Download Anna University B.Tech (Bachelor of Technology) EEE (Electrical And Electronics Engineering) 7th Sem Power System Simulation PSS Lab Manual Question Paper.

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 9

1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 9

1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 9

1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 11

Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 9

1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 11

Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 9

1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 11

Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 9

1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 11

Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 11

Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 7

To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

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(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

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1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

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Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

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(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

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Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

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DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

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(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

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DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

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DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 11

Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 8

4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 9

1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 11

Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

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Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

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1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

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Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

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(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

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Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

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DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

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1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

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EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

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VISION

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? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

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COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

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EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

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Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

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1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

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Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

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(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

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Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

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DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

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1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

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Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

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Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

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Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

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DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

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1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

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Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

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1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

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Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

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Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

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Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 24

Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 24

Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 27

1. What is meant by singular transformation method?

The matrix formed by graph theory.

2. What is meant by inspection method?

The admittance matrix calculated directly is called inspection method.

3. What is meant by bus?

Bus is junction point of transmission line.

4. What are the components of a power system?

Generator, Transformer, transmission line, load

5. What is meant by single line diagram?

Power system represented in simple graphical view

6. How are the loads represented in reactance or impedance diagram?

loads represented in reactance diagram resistor with reactor.

7. What are the different methods to solve bus admittance matrix?

Inspection method, direct method

8. What are the elements of the bus admittance matrix?

Reactance

9. What are the elements of the bus impedance matrix?

Resistor and reactor

10. What are the methods available for forming bus impedance matrix?

1. Bus building algorithm

2. using y bus

11. Define per unit value.

Per unit is defined as the ratio of actual value to base value

12. What are the advantages of per unit computations?

The manufacture is used as common value

It is easy to understand.

Viva - voce

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

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Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

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Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

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1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

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Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 27

1. What is meant by singular transformation method?

The matrix formed by graph theory.

2. What is meant by inspection method?

The admittance matrix calculated directly is called inspection method.

3. What is meant by bus?

Bus is junction point of transmission line.

4. What are the components of a power system?

Generator, Transformer, transmission line, load

5. What is meant by single line diagram?

Power system represented in simple graphical view

6. How are the loads represented in reactance or impedance diagram?

loads represented in reactance diagram resistor with reactor.

7. What are the different methods to solve bus admittance matrix?

Inspection method, direct method

8. What are the elements of the bus admittance matrix?

Reactance

9. What are the elements of the bus impedance matrix?

Resistor and reactor

10. What are the methods available for forming bus impedance matrix?

1. Bus building algorithm

2. using y bus

11. Define per unit value.

Per unit is defined as the ratio of actual value to base value

12. What are the advantages of per unit computations?

The manufacture is used as common value

It is easy to understand.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 28

Expt. No. 5: LOAD FREQUENCY DYNAMICS OF SINGLE AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a single area power

system with and without load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality of power

supply. A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor

systems) of the system leading to change in system frequency. The speed change form synchronous speed initiates

the governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new Model by selecting File - New ? Model.

3. Pick up the blocks from the simulink library browser and form a block diagram.

4. After forming the block diagram, save the block diagram.

5. Double click the scope and view the result.

Exercise:

1. An isolated power station has the following parameters:

Turbine time constant, ? T = 0.5sec, Governor time constant, ? g = 0.2sec

Generator inertia constant, H = 5sec, Governor speed regulation = R per unit

The load varies by 0.8 percent for a 1 percent change in frequency, i.e, D = 0.8

(a) Use the Routh ? Hurwitz array to find the range of R for control system stability.

(b) Use MATLAB to obtain the root locus plot.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

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Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 10

>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 12

function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 24

Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 27

1. What is meant by singular transformation method?

The matrix formed by graph theory.

2. What is meant by inspection method?

The admittance matrix calculated directly is called inspection method.

3. What is meant by bus?

Bus is junction point of transmission line.

4. What are the components of a power system?

Generator, Transformer, transmission line, load

5. What is meant by single line diagram?

Power system represented in simple graphical view

6. How are the loads represented in reactance or impedance diagram?

loads represented in reactance diagram resistor with reactor.

7. What are the different methods to solve bus admittance matrix?

Inspection method, direct method

8. What are the elements of the bus admittance matrix?

Reactance

9. What are the elements of the bus impedance matrix?

Resistor and reactor

10. What are the methods available for forming bus impedance matrix?

1. Bus building algorithm

2. using y bus

11. Define per unit value.

Per unit is defined as the ratio of actual value to base value

12. What are the advantages of per unit computations?

The manufacture is used as common value

It is easy to understand.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 28

Expt. No. 5: LOAD FREQUENCY DYNAMICS OF SINGLE AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a single area power

system with and without load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality of power

supply. A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor

systems) of the system leading to change in system frequency. The speed change form synchronous speed initiates

the governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new Model by selecting File - New ? Model.

3. Pick up the blocks from the simulink library browser and form a block diagram.

4. After forming the block diagram, save the block diagram.

5. Double click the scope and view the result.

Exercise:

1. An isolated power station has the following parameters:

Turbine time constant, ? T = 0.5sec, Governor time constant, ? g = 0.2sec

Generator inertia constant, H = 5sec, Governor speed regulation = R per unit

The load varies by 0.8 percent for a 1 percent change in frequency, i.e, D = 0.8

(a) Use the Routh ? Hurwitz array to find the range of R for control system stability.

(b) Use MATLAB to obtain the root locus plot.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 29

(c) The governor speed regulation is set to R = 0.05 per unit. The turbine rated output is 250MW at nominal

frequency of 60Hz. A sudden load change of 50 MW (?P L = 0.2 per unit) occurs.

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Without integral controller: (simulink block diagram)

With integral controller: (simulink block diagram)

Exercise: 1

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 PU MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2 s,

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Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

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ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

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COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

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EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

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Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

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1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

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(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

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Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

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DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

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Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 27

1. What is meant by singular transformation method?

The matrix formed by graph theory.

2. What is meant by inspection method?

The admittance matrix calculated directly is called inspection method.

3. What is meant by bus?

Bus is junction point of transmission line.

4. What are the components of a power system?

Generator, Transformer, transmission line, load

5. What is meant by single line diagram?

Power system represented in simple graphical view

6. How are the loads represented in reactance or impedance diagram?

loads represented in reactance diagram resistor with reactor.

7. What are the different methods to solve bus admittance matrix?

Inspection method, direct method

8. What are the elements of the bus admittance matrix?

Reactance

9. What are the elements of the bus impedance matrix?

Resistor and reactor

10. What are the methods available for forming bus impedance matrix?

1. Bus building algorithm

2. using y bus

11. Define per unit value.

Per unit is defined as the ratio of actual value to base value

12. What are the advantages of per unit computations?

The manufacture is used as common value

It is easy to understand.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 28

Expt. No. 5: LOAD FREQUENCY DYNAMICS OF SINGLE AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a single area power

system with and without load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality of power

supply. A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor

systems) of the system leading to change in system frequency. The speed change form synchronous speed initiates

the governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new Model by selecting File - New ? Model.

3. Pick up the blocks from the simulink library browser and form a block diagram.

4. After forming the block diagram, save the block diagram.

5. Double click the scope and view the result.

Exercise:

1. An isolated power station has the following parameters:

Turbine time constant, ? T = 0.5sec, Governor time constant, ? g = 0.2sec

Generator inertia constant, H = 5sec, Governor speed regulation = R per unit

The load varies by 0.8 percent for a 1 percent change in frequency, i.e, D = 0.8

(a) Use the Routh ? Hurwitz array to find the range of R for control system stability.

(b) Use MATLAB to obtain the root locus plot.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 29

(c) The governor speed regulation is set to R = 0.05 per unit. The turbine rated output is 250MW at nominal

frequency of 60Hz. A sudden load change of 50 MW (?P L = 0.2 per unit) occurs.

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Without integral controller: (simulink block diagram)

With integral controller: (simulink block diagram)

Exercise: 1

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 PU MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2 s,

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 30

Viva - voce

Load change 60 MW, The load varies by 0.8 percent for a 1 percent change in frequency, Determine the steady

state frequency deviation in Hz

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Exercise: 2

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 p.u. MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2

sec, Load change 60 MW, The system is equipped with secondary integral control loop and the integral controller

gain is K f = 1. Obtain the frequency deviation for a step response

Result:

Thus, the modeling and analysis of the frequency and tie-line flow dynamics of a single area power system with

and without load frequency controllers (LFC) were obtained using MATLAB/ simulink.

Outcome:

By doing the experiment, the students can understand the modeling and analysis of the frequency and tie-line flow

dynamics of a single area power system with and without load frequency controllers (LFC) using MATLAB/Simulink

Application:

To maintain the power and frequency constant in electrical power system.

1. What is meant by single area system?

If the generation system is considering only one generation unit and one load area it can be treated as a single area system

2. What is meant by load frequency control?

Load frequency control, as the name signifies, regulates the power flow between different areas while holding the frequency

constant

3. What is meant by automatic generation control?

In an electric power system, automatic generation control (AGC) is a system for adjusting the power output of multiple

generators at different power plants, in response to changes in the load

4. What is meant by speed regulation?

Speed regulation is no load speed to full load speed and no load speed.

5. What is meant by inertia constant?

Inertia constant is ?the ratio of kinetic energy of a rotor of a synchronous machine to the rating of a machine

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

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Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 24

Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 27

1. What is meant by singular transformation method?

The matrix formed by graph theory.

2. What is meant by inspection method?

The admittance matrix calculated directly is called inspection method.

3. What is meant by bus?

Bus is junction point of transmission line.

4. What are the components of a power system?

Generator, Transformer, transmission line, load

5. What is meant by single line diagram?

Power system represented in simple graphical view

6. How are the loads represented in reactance or impedance diagram?

loads represented in reactance diagram resistor with reactor.

7. What are the different methods to solve bus admittance matrix?

Inspection method, direct method

8. What are the elements of the bus admittance matrix?

Reactance

9. What are the elements of the bus impedance matrix?

Resistor and reactor

10. What are the methods available for forming bus impedance matrix?

1. Bus building algorithm

2. using y bus

11. Define per unit value.

Per unit is defined as the ratio of actual value to base value

12. What are the advantages of per unit computations?

The manufacture is used as common value

It is easy to understand.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 28

Expt. No. 5: LOAD FREQUENCY DYNAMICS OF SINGLE AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a single area power

system with and without load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality of power

supply. A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor

systems) of the system leading to change in system frequency. The speed change form synchronous speed initiates

the governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new Model by selecting File - New ? Model.

3. Pick up the blocks from the simulink library browser and form a block diagram.

4. After forming the block diagram, save the block diagram.

5. Double click the scope and view the result.

Exercise:

1. An isolated power station has the following parameters:

Turbine time constant, ? T = 0.5sec, Governor time constant, ? g = 0.2sec

Generator inertia constant, H = 5sec, Governor speed regulation = R per unit

The load varies by 0.8 percent for a 1 percent change in frequency, i.e, D = 0.8

(a) Use the Routh ? Hurwitz array to find the range of R for control system stability.

(b) Use MATLAB to obtain the root locus plot.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 29

(c) The governor speed regulation is set to R = 0.05 per unit. The turbine rated output is 250MW at nominal

frequency of 60Hz. A sudden load change of 50 MW (?P L = 0.2 per unit) occurs.

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Without integral controller: (simulink block diagram)

With integral controller: (simulink block diagram)

Exercise: 1

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 PU MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2 s,

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 30

Viva - voce

Load change 60 MW, The load varies by 0.8 percent for a 1 percent change in frequency, Determine the steady

state frequency deviation in Hz

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Exercise: 2

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 p.u. MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2

sec, Load change 60 MW, The system is equipped with secondary integral control loop and the integral controller

gain is K f = 1. Obtain the frequency deviation for a step response

Result:

Thus, the modeling and analysis of the frequency and tie-line flow dynamics of a single area power system with

and without load frequency controllers (LFC) were obtained using MATLAB/ simulink.

Outcome:

By doing the experiment, the students can understand the modeling and analysis of the frequency and tie-line flow

dynamics of a single area power system with and without load frequency controllers (LFC) using MATLAB/Simulink

Application:

To maintain the power and frequency constant in electrical power system.

1. What is meant by single area system?

If the generation system is considering only one generation unit and one load area it can be treated as a single area system

2. What is meant by load frequency control?

Load frequency control, as the name signifies, regulates the power flow between different areas while holding the frequency

constant

3. What is meant by automatic generation control?

In an electric power system, automatic generation control (AGC) is a system for adjusting the power output of multiple

generators at different power plants, in response to changes in the load

4. What is meant by speed regulation?

Speed regulation is no load speed to full load speed and no load speed.

5. What is meant by inertia constant?

Inertia constant is ?the ratio of kinetic energy of a rotor of a synchronous machine to the rating of a machine

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 31

6. What are the major control loops used in large generators?

Primary control loop

Secondary control loop

7. What is the use of secondary loop?

Secondary control loop is used to maintain the frequency as constant.

8. What is the advantage of AVR loop over ALFC loop?

AVR loop is much faster than the ALFC loop and therefore there is a tendency, for the

AVR dynamics to settle down before they can make themselves felt in the slower load ?

frequency control channel.

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Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

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is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

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DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

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them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

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PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

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training to compare, and to analyze various engineering industrial problems to find solutions

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them to find solutions for the real time problems in industry, and to design products

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broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

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COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

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EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

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Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

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(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

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DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

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Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 27

1. What is meant by singular transformation method?

The matrix formed by graph theory.

2. What is meant by inspection method?

The admittance matrix calculated directly is called inspection method.

3. What is meant by bus?

Bus is junction point of transmission line.

4. What are the components of a power system?

Generator, Transformer, transmission line, load

5. What is meant by single line diagram?

Power system represented in simple graphical view

6. How are the loads represented in reactance or impedance diagram?

loads represented in reactance diagram resistor with reactor.

7. What are the different methods to solve bus admittance matrix?

Inspection method, direct method

8. What are the elements of the bus admittance matrix?

Reactance

9. What are the elements of the bus impedance matrix?

Resistor and reactor

10. What are the methods available for forming bus impedance matrix?

1. Bus building algorithm

2. using y bus

11. Define per unit value.

Per unit is defined as the ratio of actual value to base value

12. What are the advantages of per unit computations?

The manufacture is used as common value

It is easy to understand.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 28

Expt. No. 5: LOAD FREQUENCY DYNAMICS OF SINGLE AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a single area power

system with and without load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality of power

supply. A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor

systems) of the system leading to change in system frequency. The speed change form synchronous speed initiates

the governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new Model by selecting File - New ? Model.

3. Pick up the blocks from the simulink library browser and form a block diagram.

4. After forming the block diagram, save the block diagram.

5. Double click the scope and view the result.

Exercise:

1. An isolated power station has the following parameters:

Turbine time constant, ? T = 0.5sec, Governor time constant, ? g = 0.2sec

Generator inertia constant, H = 5sec, Governor speed regulation = R per unit

The load varies by 0.8 percent for a 1 percent change in frequency, i.e, D = 0.8

(a) Use the Routh ? Hurwitz array to find the range of R for control system stability.

(b) Use MATLAB to obtain the root locus plot.

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(c) The governor speed regulation is set to R = 0.05 per unit. The turbine rated output is 250MW at nominal

frequency of 60Hz. A sudden load change of 50 MW (?P L = 0.2 per unit) occurs.

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Without integral controller: (simulink block diagram)

With integral controller: (simulink block diagram)

Exercise: 1

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 PU MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2 s,

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 30

Viva - voce

Load change 60 MW, The load varies by 0.8 percent for a 1 percent change in frequency, Determine the steady

state frequency deviation in Hz

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Exercise: 2

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 p.u. MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2

sec, Load change 60 MW, The system is equipped with secondary integral control loop and the integral controller

gain is K f = 1. Obtain the frequency deviation for a step response

Result:

Thus, the modeling and analysis of the frequency and tie-line flow dynamics of a single area power system with

and without load frequency controllers (LFC) were obtained using MATLAB/ simulink.

Outcome:

By doing the experiment, the students can understand the modeling and analysis of the frequency and tie-line flow

dynamics of a single area power system with and without load frequency controllers (LFC) using MATLAB/Simulink

Application:

To maintain the power and frequency constant in electrical power system.

1. What is meant by single area system?

If the generation system is considering only one generation unit and one load area it can be treated as a single area system

2. What is meant by load frequency control?

Load frequency control, as the name signifies, regulates the power flow between different areas while holding the frequency

constant

3. What is meant by automatic generation control?

In an electric power system, automatic generation control (AGC) is a system for adjusting the power output of multiple

generators at different power plants, in response to changes in the load

4. What is meant by speed regulation?

Speed regulation is no load speed to full load speed and no load speed.

5. What is meant by inertia constant?

Inertia constant is ?the ratio of kinetic energy of a rotor of a synchronous machine to the rating of a machine

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 31

6. What are the major control loops used in large generators?

Primary control loop

Secondary control loop

7. What is the use of secondary loop?

Secondary control loop is used to maintain the frequency as constant.

8. What is the advantage of AVR loop over ALFC loop?

AVR loop is much faster than the ALFC loop and therefore there is a tendency, for the

AVR dynamics to settle down before they can make themselves felt in the slower load ?

frequency control channel.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 32

Expt.No.6: LOAD FREQUENCY DYNAMICS OF TWO AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a two area power

system without and with load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality power supply.

A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor systems) of

the system leading to change in system frequency. The speed change form synchronous speed initiates the

governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units

Procedure:

1. Enter the command window of the MATLAB

2. Create a new model by selecting File - New ? Model

3. Pick up the blocks from the simulink library browser and form a block diagram

4. After forming the block diagram, save the block diagram

5. Double click the scope and view the result

Exercise:

A Two- area system connected by a tie- line has the following parameters on a 1000 MVA common base.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 5

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 6

Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 14

Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 15

(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 16

Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 24

Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 27

1. What is meant by singular transformation method?

The matrix formed by graph theory.

2. What is meant by inspection method?

The admittance matrix calculated directly is called inspection method.

3. What is meant by bus?

Bus is junction point of transmission line.

4. What are the components of a power system?

Generator, Transformer, transmission line, load

5. What is meant by single line diagram?

Power system represented in simple graphical view

6. How are the loads represented in reactance or impedance diagram?

loads represented in reactance diagram resistor with reactor.

7. What are the different methods to solve bus admittance matrix?

Inspection method, direct method

8. What are the elements of the bus admittance matrix?

Reactance

9. What are the elements of the bus impedance matrix?

Resistor and reactor

10. What are the methods available for forming bus impedance matrix?

1. Bus building algorithm

2. using y bus

11. Define per unit value.

Per unit is defined as the ratio of actual value to base value

12. What are the advantages of per unit computations?

The manufacture is used as common value

It is easy to understand.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 28

Expt. No. 5: LOAD FREQUENCY DYNAMICS OF SINGLE AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a single area power

system with and without load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality of power

supply. A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor

systems) of the system leading to change in system frequency. The speed change form synchronous speed initiates

the governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new Model by selecting File - New ? Model.

3. Pick up the blocks from the simulink library browser and form a block diagram.

4. After forming the block diagram, save the block diagram.

5. Double click the scope and view the result.

Exercise:

1. An isolated power station has the following parameters:

Turbine time constant, ? T = 0.5sec, Governor time constant, ? g = 0.2sec

Generator inertia constant, H = 5sec, Governor speed regulation = R per unit

The load varies by 0.8 percent for a 1 percent change in frequency, i.e, D = 0.8

(a) Use the Routh ? Hurwitz array to find the range of R for control system stability.

(b) Use MATLAB to obtain the root locus plot.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 29

(c) The governor speed regulation is set to R = 0.05 per unit. The turbine rated output is 250MW at nominal

frequency of 60Hz. A sudden load change of 50 MW (?P L = 0.2 per unit) occurs.

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Without integral controller: (simulink block diagram)

With integral controller: (simulink block diagram)

Exercise: 1

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 PU MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2 s,

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 30

Viva - voce

Load change 60 MW, The load varies by 0.8 percent for a 1 percent change in frequency, Determine the steady

state frequency deviation in Hz

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Exercise: 2

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 p.u. MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2

sec, Load change 60 MW, The system is equipped with secondary integral control loop and the integral controller

gain is K f = 1. Obtain the frequency deviation for a step response

Result:

Thus, the modeling and analysis of the frequency and tie-line flow dynamics of a single area power system with

and without load frequency controllers (LFC) were obtained using MATLAB/ simulink.

Outcome:

By doing the experiment, the students can understand the modeling and analysis of the frequency and tie-line flow

dynamics of a single area power system with and without load frequency controllers (LFC) using MATLAB/Simulink

Application:

To maintain the power and frequency constant in electrical power system.

1. What is meant by single area system?

If the generation system is considering only one generation unit and one load area it can be treated as a single area system

2. What is meant by load frequency control?

Load frequency control, as the name signifies, regulates the power flow between different areas while holding the frequency

constant

3. What is meant by automatic generation control?

In an electric power system, automatic generation control (AGC) is a system for adjusting the power output of multiple

generators at different power plants, in response to changes in the load

4. What is meant by speed regulation?

Speed regulation is no load speed to full load speed and no load speed.

5. What is meant by inertia constant?

Inertia constant is ?the ratio of kinetic energy of a rotor of a synchronous machine to the rating of a machine

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 31

6. What are the major control loops used in large generators?

Primary control loop

Secondary control loop

7. What is the use of secondary loop?

Secondary control loop is used to maintain the frequency as constant.

8. What is the advantage of AVR loop over ALFC loop?

AVR loop is much faster than the ALFC loop and therefore there is a tendency, for the

AVR dynamics to settle down before they can make themselves felt in the slower load ?

frequency control channel.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 32

Expt.No.6: LOAD FREQUENCY DYNAMICS OF TWO AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a two area power

system without and with load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality power supply.

A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor systems) of

the system leading to change in system frequency. The speed change form synchronous speed initiates the

governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units

Procedure:

1. Enter the command window of the MATLAB

2. Create a new model by selecting File - New ? Model

3. Pick up the blocks from the simulink library browser and form a block diagram

4. After forming the block diagram, save the block diagram

5. Double click the scope and view the result

Exercise:

A Two- area system connected by a tie- line has the following parameters on a 1000 MVA common base.

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Area 1 2

Speed regulation R 1=0.05 R 2=0.0625

damping coefficient D 1=0.6 D 2=0.9

Inertia constant H 1=5 H 2=4

Base power 1000MVA 1000MVA

Governor time constant ? g1 = 0.2sec ? g1 = 0.3sec

Turbine time constant ? T1 =0.5sec ? T1 =0.6sec

The units are operating in parallel at the nominal frequency of 60Hz. The synchronizing power coefficient is

computed from the initial operating condition and is given to be P s = 2 p.u. A load change of 187.5 MW occurs in

area1.

(a) Determine the new steady state frequency and the change in the tie-line flow.

(b) Construct the SIMULINK block diagram and obtain the frequency deviation response for the condition in part (a).

Simulink block diagram:

Result:

Thus, the modeling and analysis of the frequency and tie-line flow dynamics of a two area power system with and

without load frequency controllers (LFC) were obtained using MATLAB / Simulink.

Outcome:

By doing the experiment, the students can understand the modeling and analysis of the frequency and tie-line flow

dynamics of a two area power system with and without load frequency controllers (LFC) using MATLAB/Simulink.

FirstRanker.com - FirstRanker's Choice

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 1

?

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

EE 6711- POWER SYSTEM SIMULATION LABORATORY

VII SEMESTER - R 2013

Name :

Register No. :

Class :

LABORATORY MANUAL

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 2

VISION

VISION

is committed to provide highly disciplined, conscientious and

enterprising professionals conforming to global standards through value based quality education and training.

? To provide competent technical manpower capable of meeting requirements of the industry

? To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels

? To train the students to sell his brawn and brain to the highest bidder but to never put a price tag on heart and

soul

DEPARTMENT OF ELECTRICAL AND ELECTRONICS

ENGINEERING

To impart professional education integrated with human values to the younger generation, so as to shape

them as proficient and dedicated engineers, capable of providing comprehensive solutions to the challenges in

deploying technology for the service of humanity

? To educate the students with the state-of-art technologies to meet the growing challenges of the electronics

industry

? To carry out research through continuous interaction with research institutes and industry, on advances in

communication systems

? To provide the students with strong ground rules to facilitate them for systematic learning, innovation and

ethical practices

MISSION

MISSION

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 3

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science and fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems and use this knowledge to acquire higher

education

2. Core Competence

To train the students in Electrical and Electronics technologies so that they apply their knowledge and

training to compare, and to analyze various engineering industrial problems to find solutions

3. Breadth

To provide relevant training and experience to bridge the gap between theory and practice which enables

them to find solutions for the real time problems in industry, and to design products

4. Professionalism

To inculcate professional and effective communication skills, leadership qualities and team spirit in the

students to make them multi-faceted personalities and develop their ability to relate engineering issues to

broader social context

5. Lifelong Learning/Ethics

To demonstrate and practice ethical and professional responsibilities in the industry and society in the large,

through commitment and lifelong learning needed for successful professional career

PROGRAMME OUTCOMES (POs)

a. To demonstrate and apply knowledge of Mathematics, Science and engineering fundamentals in Electrical

and Electronics Engineering field

b. To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety and manufacturability

c. To demonstrate the competency to use software tools for computation, simulation and testing of electrical

and electronics engineering circuits

d. To identify, formulate and solve electrical and electronics engineering problems

e. To demonstrate an ability to visualize and work on laboratory and multidisciplinary tasks

f. To function as a member or a leader in multidisciplinary activities

g. To communicate in verbal and written form with fellow engineers and society at large

h. To understand the impact of Electrical and Electronics Engineering in the society and demonstrate

awareness of contemporary issues and commitment to give solutions exhibiting social responsibility

i. To demonstrate professional & ethical responsibilities

j. To exhibit confidence in self-education and ability for lifelong learning

k. To participate and succeed in competitive exams

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 4

COURSE OBJECTIVES

COURSE OUTCOMES

EE6711 ? POWER SYSTEM SIMULATION LABORATORY

SYLLABUS

To provide better understanding of power system analysis through digital simulation.

LIST OF EXPERIMENTS:

1. Computation of Parameters and Modeling of Transmission Lines

2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks

3. Load Flow Analysis - I Solution of load flow and related problems using Gauss- Seidel Method.

4. Load Flow Analysis - II: Solution of load flow and related problems using Newton Raphson.

5. Fault Analysis

6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System

7. Transient Stability Analysis of Multi machine Power Systems

8. Electromagnetic Transients in Power Systems

9. Load ?Frequency Dynamics of Single- Area and Two-Area Power Systems

10. Economic Dispatch in Power Systems.

1. Ability to understand the concept of MATLAB programming in solving power systems problems.

2. Ability to understand the concept of MATLAB programming in solving parameters of transmission lines.

3. Ability to understand the concept of MATLAB programming in solving medium transmission line parameters.

4. Ability to understand the concept of MATLAB programming in formation of bus admittance and impedance

matrices.

5. Ability to understand the concept of MATLAB / simulink modeling of single area system.

6. Ability to understand the concept of MATLAB / simulink modeling of two area system.

7. Ability to understand the concept of MATLAB programming in analyzing transient and small signal stability

analysis of SMIB system.

8. Ability to understand the concept of MATLAB programming in solving economic dispatch in power systems.

9. Ability to understand the concept of MATLAB Programming in analyzing transient stability analysis of multi

machine infinite bus system.

10. Ability to understand the concept of MATLAB programming in solving power flow analysis using Gauss

siedel method.

11. Ability to understand the concept of MATLAB programming in solving power flow analysis using Newton

Raphson method.

12. Ability to understand the concept of MATLAB programming in solving fault analysis in power system.

13. Ability to understand the concept of MATLAB programming in analyzing transient stability analysis of multi

machine power systems.

14. Ability to understand the concept of MATLAB / Simulink modeling of FACTS devices.

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EE6711 ? POWER SYSTEM SIMULATION LABORATORY

CONTENTS

Sl. No. Name of the experiment Page No.

CYCLE 1 EXPERIMENTS

1 Introduction to MATLAB 05

2 Computation of transmission line parameters 13

3 Modeling of transmission line parameters 19

4 Formation of bus admittance and impedance matrices 21

5 Load frequency dynamics of single area system 26

6 Load frequency dynamics of two area system 29

7 Transient and small signal stability analysis of single machine infinite bus system 32

CYCLE 2 EXPERIMENTS

8 Economic dispatch in power systems using MATLAB 35

9 Transient Stability Analysis of Multi machine Infinite bus system 41

10 Solution of power flow using Gauss Seidel method. 44

11 Solution of power flow using Newton Raphson method 50

12 Fault analysis in power system 58

Mini Project

13 Modeling of FACTS devices using SIMULINK 68

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Expt. No.1: INTRODUCTION TO MATLAB

Aim:

To procure sufficient knowledge in MATLAB to solve the power system Problems

Software required:

MATLAB

Theory:

1. Introduction to MATLAB:

MATLAB is a high performance language for technical computing. It integrates computation, visualization and

programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical

notation. MATLAB is numeric computation software for engineering and scientific calculations. MATLAB is primary

tool for matrix computations. MATLAB is being used to simulate random process, power system, control system and

communication theory. MATLAB comprising lot of optional tool boxes and block set like control system, optimization,

and power system and so on.

1.1 Typical uses:

? Mathematics tools and computation

? Algorithm development

? Modeling, simulation and prototype

? Data analysis, exploration and visualization

? Scientific and engineering graphics

? Application development, including graphical user interface building

MATLAB is a widely used tool in electrical engineering community. It can be used for simple mathematical

manipulation with matrices for understanding and teaching basic mathematical and engineering concepts and even

for studying and simulating actual power system and electrical system in general. The original concept of a small

and handy tool has evolved replace and/or enhance the usage of traditional simulation tool for advanced engineering

applications.to become an engineering work house. It is now accepted that MATLAB and its numerous tool boxes

1.2 Getting started with MATLAB:

To open the MATLAB applications double click the MATLAB icon on the desktop. To quit from MATLAB type?

>> quit

(Or)

>>exit

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To select the (default) current directory click ON the icon [?] and browse for the folder named ?D:\SIMULAB\xxx?,

where xxx represents roll number of the individual candidate in which a folder should be created already.

When you start MATLAB you are presented with a window from which you can enter commands interactively.

Alternatively, you can put your commands in an M- file and execute it at the MATLAB prompt. In practice you will

probably do a little of both. One good approach is to incrementally create your file of commands by first executing

them.

M-files can be classified into following 2 categories,

i) Script M-files ? Main file contains commands and from which functions can also be

called

ii) Function M-files ? Function file that contains function command at the first line of the

M-file

M-files to be created should be placed in your default directory. The M-files developed can be loaded into the work

space by just typing the M-file name.To load and run a M-file named ?ybus.m? in the workspace

>> ybus

These M-files of commands must be given the file extension of ?.m?. However M-files are not limited to being a

series of commands that you don?t want to type at the MATLAB window, they can also be used to create user defined

function. It turns out that a MATLAB tool box is usually nothing more than a grouping of M-files that someone created

to perform a special type of analysis like control system design and power system analysis. One of the more

generally useful MATLAB tool boxes is simulink ? a drag and-drop dynamic system simulation environment. This will

be used extensively in laboratory, forming the heart of the computer aided control system design (CACSD)

methodology that is used.

>> Simulink

At the MATLAB prompt type simulink and brings up the ?Simulink Library Browser?. Each of the items in the

Simulink Library Browser are the top level of a hierarchy of palette of elements that you can add to a simulink model

of your own creation. The ?simulink? pallete contains the majority of the elements used in the MATLAB. Simulink

has built into it a variety of integration algorithm for integrating the dynamic equations. You can place the dynamic

equations of your system into simulink in four ways.

1 Using integrators

2. Using transfer functions

3. Using state space equations

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4. Using S- functions (the most versatile approach)

Once you have the dynamics in place you can apply inputs from the ?sources? palettes and look at the results in

the ?sinks? palette. Finally, the most important MATLAB feature is help. At the MATLAB Prompt simply typing

helpdesk gives you access to searchable help as well as all the MATLAB manuals.

>> helpdesk

To get the details about the command name sqrt, just type?

>> help sqrt

(like 5+j8) and matrices with the same ease as manipulating scalars (like5,8). Before diving into the actual

commands everybody must spend a few moments reviewing the main MATLAB data types. The three most common

data types you may see are,

1) arrays 2) strings 3) structures Where sqrt is the command name and you will get pretty good description in

the MATLAB window as follows.

/SQRT Square root. SQRT(X) is the square root of the elements of X. Complex results are produced if X is not

positive.

1.3 MATLAB workspace:

The workspace is the window where you execute MATLAB commands (Ref. figure-1). The best way to probe the

workspace is to type whos. This command shows you all the variables that are currently in workspace. You should

always change working directory to an appropriate location under your user name.Another useful workspace like

command is

>>clear all

It eliminates all the variables in your workspace. For example, start MATLAB and execute the following sequence

of commands

>>a=2;

>>b=5;

>>whos

>>clear all

The first two commands loaded the two variables a and b to the workspace and assigned value of 2 and 5

respectively. The clear all command clear the variables available in the work space. The arrow keys are real handy

in MATLAB. When typing in long expression at the command line, the up arrow scrolls through previous commands

and down arrow advances the other direction. Instead of retyping a previously entered command just hit the up arrow

until you find it. If you need to change it slightly the other arrows let you position the cursor anywhere. Finally any

DOS command can be entered in MATLAB as long as it is preceded by any exclamation mark.

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1.3 MATLAB data types:

The most distinguishing aspect of MATLAB is that it allows the user to manipulate vectors As for as MATLAB is

concerned a scalar is also a 1 x 1 array. For example clear your workspace and execute the commands.

>>a=4.2:

>>A=[1 4;6 3];

>>whos

Two things should be evident. First MATLAB distinguishes the case of a variable name and that both a and A are

considered arrays. Now let?s look at the content of A and a.

>>a

>>A

Again two things are important from this example. First anybody can examine the contents of any variables simply

by typing its name at the MATLAB prompt. When typing in a matrix space between elements separate columns,

whereas semicolon separate rows. For practice, create the matrix in your workspace by typing it in all the MATLAB

prompt.

>>B= [3 0 -1; 4 4 2;7 2 11];

(use semicolon(;) to represent the end of a row)

>>B

Arrays can be constructed automatically. For instance to create a time vector where the time points start at 0

seconds and go up to 5 seconds by increments of 0.001

>>mytime =0:0.001:5;

Automatic construction of arrays of all ones can also be created as follows,

>>myone=ones (3,2)

1.4 Scalar versus array mathematical operation:

Since MATLAB treats everything as an array, you can add matrices as easily as scalars.

Example:

>>clear all

>> a=4;

>> A=7;

>>alpha=a+A;

>>b= [1 2; 3 4];

>>B= [6 5; 3 1];

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>>beta=b+B

The violation of the rules in matrix algebra can be understood by the following example.

>>clear all

>>b=[1 2;3 4];

>>B=[6 7];

>>beta=b*B

In contrast to matrix algebra rules, the need may arise to divide, multiply, raise to a power one vector by another,

element by element. The typical scalar commands are used for this ?+,-,/, *, ^? except you put a ?.? in front of the

scalar command. That is, if you need to multiply the elements of [1 2 3 4] by [6 7 8 9], just

>> [1 2 3 4].*[6 7 8 9]

1.6 Conditional statements :

Like most programming languages, MATLAB supports a variety of conditional statements and looping statements.

To explore these simply type

>>help if

>>help for

>>help while

Example :

]Looping :

>>if z=0

>>y=0

>>else

>>y=1/z

>>end

>>for n=1:2:10

>>s=s+n^2

>>end

- Yields the sum of 1^2+3^2+5^2+7^2+9^2

1.7 Plotting:

MATLAB?s potential in visualizing data is pretty amazing. One of the nice features is that with the simplest of

commands you can have quite a bit of capability.

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Graphs can be plotted and can be saved in different formulas.

>> clear all

>> t=0:10:360;

>> y=sin (pi/180 * t);

To see a plot of y versus t simply type,

>> plot(t,y)

To add a label, legend, grid and title use

>> xlabel (?Time in sec?);

>>ylabel (?Voltage in volts?)

>>title (?Sinusoidal O/P?);

>>legend (?Signal?);

The commands above provide the most plotting capability and represent several shortcuts to the low-level

approach to generating MATLAB plots, specifically the use of handle graphics. The helpdesk provides access to a

pdf manual on handle graphics for those really interested in it.

1.8 Functions:

As mentioned earlier, a M-file can be used to store a sequence of commands or a user-defined function. The

commands and functions that comprise the new function must be put in a file whose name defines the name of the

new function, with a filename extension of '.m'. A function is a generalized input/output device. We can give some

input arguments and provides some output. MATLAB functions allow us much capability to expand MATLAB?s

usefulness. We will start by looking at the help on functions :

>>help function

We will create our own function that given an input matrix returns a vector containing the admittance matrix(y) of

given impedance matrix(z)?

z= [5 2 4;

1 4 5] as input, the output would be,

y= [0.2 0.5 0.25;

1 0.25 0.2] which is the reciprocal of each elements.

To perform the same name the function ?admin? and noted that ?admin? must be stored in a function M-file named

?admin.m?. Using an editor, type the following commands and save as ?admin.m?.

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function y = admin(z)

y = 1./z

return

Simply call the function admin from the workspace as follows,

>>z=[5 2 4;

1 4 5]

>>admin(z)

The output will be,

ans = 0.2 0.5 0.25

1 0.25 0.2

Otherwise the same function can be called for any times from any script file provided the function M-file is available

in the current directory. With this introduction anybody can start programming in MATLAB and can be updated

themselves by using various commands and functions available. Concerned with the ?Power System Simulation

Laboratory?, initially solve the Power System Problems manually, list the expressions used in the problem and then

build your own MATLAB program or function.

Result:

Thus, the sufficient knowledge about MATLAB to solve power system problems were obtained.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving power

systems problems.

Application:

MATLAB Used

Algorithm development

Scientific and engineering graphics

Modeling, simulation, and prototyping

Application development, including Graphical User Interface building

Math and computation

Data analysis, exploration, and visualization

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 13

1. What is meant by MATLAB?

MATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming

in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation.

2. What are the different functions used in MATLAB?

The different function intersect , bitshift, categorical, isfield

3. What are the different operators used in MATLAB?

Arithmetic, Relational Operations, Logical Operations, Set Operations, Bit-Wise Operations

4. What are the different looping statements used in MATLAB?

For , while

5. What are the different conditional statements used in MATLAB?

If, else

6. What is Simulink?

Simulink, developed by Math Works, is a graphical programming environment for modeling, simulating and analyzing multi

domain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block

libraries.

7. What are the four basic functions to solve Ordinary Differential Equations (ODE)?

ode45, ode15s, ode15i

8. Explain how polynomials can be represented in MATLAB?

poly, polyval, polyvalm , roots

9. What is meant by M-file?

An m-file, or script file, is a simple text file where you can place MATLAB commands. When the file is run, MATLAB reads

the commands and executes them exactly as it would if you had typed each command sequentially at the MATLAB prompt.

10. What is Interpolation and Extrapolation in MATLAB?

Interpolation in MATLAB

is divided into techniques for data points on a grid and scattered data points.

11. List out some of the common toolboxes present in MATLAB?

Control system tool box, power system tool box, communication tool box,

12. What are the MATLAB System Parts?

MATLAB Language, MATLAB working environment, Graphics handler, MATLAB mathematical library, MATLAB Application

Program Interface.

13. What are the different applications of MATLAB?

Algorithm development, Scientific and engineering graphics, Modeling, simulation, and prototyping, Application

development, including Graphical User Interface building, Math and computation,Data analysis, exploration, and

visualization

Viva - voce

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Aim:

Expt.No.2: COMPUTATION OF TRANSMISSION LINES

PARAMETERS

To determine the positive sequence line parameters L and C per phase per kilometer of a three phase single and

double circuit transmission lines for different conductor arrangements

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Algorithm:

Step 1: Start the Program

Step 2: Get the input values for distance between the conductors and bundle spacing of

D 12, D 23 and D 13

Step 3: From the formula given calculate GMD

GMD= (D 12* D 23*D 13)

1/3

Step 4: Calculate the Value of Impedance and Capacitance of the line

Step 5: End the Program

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Exercise:1

A three phase transposed line has its conductors placed at a distance of 11 m, 11 m & 22 m. The conductors have

a diameter of 3.625cm Calculate the inductance and capacitance of the transposed conductors.

(a) Determine the inductance and capacitance per phase per kilometer of the above three lines.

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(b) Verify the results using the MATLAB program.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Program:

%3 phase single circuit

D12=input('enter the distance between D12in cm: ');

D23=input('enter the distance between D23in cm: ');

D31=input('enter the distance between D31in cm: ');

d=input('enter the value of d: ');

r=d/2;

Ds=0.7788*r;

x=D12*D23*D31;

Deq=nthroot(x,3);

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Y=log(Deq/Ds);

inductance=0.2*Y

capacitance=0.0556/(log(Deq/r))

fprintf('\n The inductance per phase per km is %f mH/ph/km \n',inductance);

fprintf('\n The capacitance per phase per km is %f mf/ph/km \n',capacitance);

Output:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Exercise:2

A 345 kV double-circuit three-phase transposed line is composed of two AC SR, 1,431,000-cmil, 45/7 bobolink

conductors per phase with vertical conductor configuration as show in figure. The conductors have a diameter of

1.427 inch and a GMR of 0.564 inch. The bundle spacing in 18 inch. Find the inductance and capacitance per phase

per Kilometer of the line.

Calculation:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

D s = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = r' = 0.7788 r

Where, r is the radius of conductor

Three phase ? symmetrical spacing :

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor &

GMR r' = 0.7788 r

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 17

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various

cases.

Program:

%3 phase double circuit

%3 phase double circuit

S = input('Enter row vector [S11, S22, S33] = ');

H = input('Enter row vector [H12, H23] = ');

d = input('Bundle spacing in inch = ');

dia = input('Conductor diameter in inch = '); r=dia/2;

Ds = input('Geometric Mean Radius in inch = ');

S11 = S(1); S22 = S(2); S33 = S(3); H12 = H(1); H23 = H(2);

a1 = -S11/2 + j*H12;

b1 = -S22/2 + j*0;

c1 = -S33/2 - j*H23;

a2 = S11/2 + j*H12;

b2 = S22/2 + j*0;

c2 = S33/2 - j*H23;

Da1b1 = abs(a1 - b1); Da1b2 = abs(a1 - b2);

Da1c1 = abs(a1 - c1); Da1c2 = abs(a1 - c2);

Db1c1 = abs(b1 - c1); Db1c2 = abs(b1 - c2);

Da2b1 = abs(a2 - b1); Da2b2 = abs(a2 - b2);

Da2c1 = abs(a2 - c1); Da2c2 = abs(a2 - c2);

Db2c1 = abs(b2 - c1); Db2c2 = abs(b2 - c2);

Da1a2 = abs(a1 - a2);

Db1b2 = abs(b1 - b2);

Dc1c2 = abs(c1 - c2);

DAB=(Da1b1*Da1b2* Da2b1*Da2b2)^0.25;

DBC=(Db1c1*Db1c2*Db2c1*Db2c2)^.25;

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 18

DCA=(Da1c1*Da1c2*Da2c1*Da2c2)^.25;

GMD=(DAB*DBC*DCA)^(1/3)

Ds = 2.54*Ds/100; r = 2.54*r/100; d = 2.54*d/100;

Dsb = (d*Ds)^(1/2); rb = (d*r)^(1/2);

DSA=sqrt(Dsb*Da1a2); rA = sqrt(rb*Da1a2);

DSB=sqrt(Dsb*Db1b2); rB = sqrt(rb*Db1b2);

DSC=sqrt(Dsb*Dc1c2); rC = sqrt(rb*Dc1c2);

GMRL=(DSA*DSB*DSC)^(1/3)

GMRC = (rA*rB*rC)^(1/3)

L=0.2*log(GMD/GMRL) % mH/km

C = 0.0556/log(GMD/GMRC) % micro F/km

Output of the program:

The inductance per phase per km is 1.377882 mH/ph/km

The capacitance per phase per km is 0.008374 mf/ph/km

Result:

Thus, the positive sequence line parameters L and C per phase per kilometer of a three phase single and double

circuit transmission lines for different conductor arrangements were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving

parameters of transmission lines.

Application :

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 19

1. What is meant by geometric mean distance?

GMD stands for Geometrical Mean Distance. It is the equivalent distance between conductors. GMD comes into picture

when there are two or more conductors per phase used as in bundled conductors.

2. What is meant by geometric mean radius?

GMR stands for Geometric mean Radius. GMR is calculated for each phase separately

3. What is meant by transposition of lines?

transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next

physical location in a regular sequence. Purpose of Transpostion. The transposition arrangement of high voltage lines

also helps to reduce the system power loss.

4. What is meant by bundling of conductors?

Mostly long distance power lines are either 220 kV or 400 kV, avoidance of the occurrence of corona is desirable. The

high voltage surface gradient is reduced considerably by having two or more conductors per phase in close proximity.

This is called Conductor bundling

5. What is meant by double circuit line?

A double-circuit transmission line has two circuits. For three-phase systems, each tower supports and insulates six

conductors. Single phase AC-power lines as used for traction current have four conductors for two circuits.

6. What is meant by ACSR conductor?

Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically

used in overhead power lines. The outer strands are high-purity aluminium, chosen for its good conductivity, low weight

and low cost

7. List out the advantages of bundled conductors.

Bundled conductors are primarily employed to reduce the corona loss and radio interference. However they have several

advantages: Bundled conductors per phase reduces the voltage gradient in the vicinity of the line.

8. What is meant by symmetrical spacing?

9. What is meant by skin effect?

Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of an electrical conductor, such

as metal wire. The effect becomes more and more apparent as the frequency increases.

10. What is meant by proximity effect?

When the conductors carry the high alternating voltage then the currents are non-uniformly distributed on the cross-

section area of the conductor. This effect is called proximity effect. The proximity effect results in the increment of the

apparent resistance of the conductor due to the presence of the other conductors carrying current in its vicinity.

11. What is meant by Ferranti effect?

In electrical engineering, the Ferranti effect is an increase in voltage occurring at the receiving end of a long transmission

line, above the voltage at the sending end. This occurs when the line is energized, but there is a very light load or the load

is disconnected.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 20

Expt.No.3: MODELING OF TRANSMISSION LINE

PARAMETERS

Aim:

To perform the modeling and performance of medium transmission lines

Software required:

MATLAB 7.6

Theory:

Transmission line has four parameters namely resistance, inductance, capacitance and conductance. The

inductance and capacitance are due to the effect of magnetic and electric fields around the conductor. The

resistance of the conductor is best determined from the manufactures data, the inductances and capacitances can

be evaluated using the formula.

Formula used:

Inductance:

The general formula:

L = 0.2 ln (D m / D s) mH / Km

Where,

D m = geometric mean distance (GMD)

Ds = geometric mean radius (GMR)

Single phase 2 wire system:

GMD = D

GMR = re-1/4 = r' = 0.7788 r

Where r is called the radius of conductor

Three phase ? symmetrical spacing:

GMD = D GMR = re-1/4 = r'

Where, r = radius of conductor & GMR = re-1/4 = r' = 0.7788 r

Capacitance:

A general formula for evaluating capacitance per phase in micro farad per km of a transmission line is given by,

C = 0.0556/ ln (Deq / r) ?F/km

Where, GMD is the ?Geometric mean distance? which is same as that defined for inductance under various cases.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 21

Algorithm:

Step 1: Start the Program.

Step 2: Get the input values for conductors.

Step 3: To find the admittance (y) and impedance (z).

Step 4: To find receiving end voltage and receiving end power.

Step 5: To find receiving end current and sending end voltage and current.

Step 6: To find the power factor and sending ending power and regulation.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by either pressing Tools ? Run.

5. View the results

Result:

Thus, the modeling and performance of medium transmission lines were obtained using MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving medium

transmission line parameters.

Application

It is used in transmission and distribution of electrical power system.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 22

1. What is meant by regulation?

Regulation is the ratio of no load to full load and no load

2. What are the different types of transmission line?

Single circuit

Double circuit

3. What is meant by efficiency of transmission line?

Transmission line efficiency is the ratio of receiving end power to sending end power.

4. What is meant by nominal ? method?

The transmission line analysis with inductor and capacitor arrange in ? model.

5. What is meant by nominal T method?

The transmission line analysis with inductor and capacitor arrange in T model.

6. What is the need for different transmission line models?

1. Nominal ?

2. Nominal T

7. What is meant by surge impedance?

The capacity to withstand the transmission line loading.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 23

Expt.No.4: FORMATION OF BUS ADMITTANCE AND

IMPEDANCE MATRICES

Aim:

To determine the bus admittance and impedance matrices for the given power system network

Software required:

MATLAB 7.6

Theory:

Formation of Y

bus

matrix:

Y-bus may be formed by inspection method only if there is no mutual coupling between the lines. Every

transmission line should be represented by ?- equivalent. Shunt impedances are added to diagonal element

corresponding to the buses at which these are connected. The off diagonal elements are unaffected. The equivalent

circuit of Tap changing transformers is included while forming Y-bus matrix.

Formation of Z

bus

matrix:

In bus impedance matrix the elements on the main diagonal are called driving point impedance and the off-

diagonal elements are called the transfer impedance of the buses or nodes. The bus impedance matrix is very useful

in fault analysis.

The bus impedance matrix can be determined by two methods. In one method we can form the bus admittance

matrix and than taking its inverse to get the bus impedance matrix. In another method, the bus impedance matrix can

be directly formed from the reactance diagram and this method requires the knowledge of the modifications of

existing bus impedance matrix due to addition of new bus or addition of a new line (or impedance) between existing

buses.

Algorithm:

Step 1: Start the program.

Step 2: Enter the bus data matrix in command window.

Step 3: Calculate the values:

Y=y bus (busdata)

Y= y bus (z)

Z bus = inv(Y)

Step 4: Form the admittance Y bus matrix.

Step 5: Form the Impedance Z bus matrix.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 24

Step 6: End the program.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new M ? file by selecting File - New ? M ? File

3. Type and save the program in the editor window.

4. Execute the program by pressing Tools ? Run.

5. View the results.

Exercise:

(i) Determine the Y bus matrix for the power system network shown in fig.

(ii) Check the results obtained in using MATLAB.

2. (i) Determine Z bus matrix for the power system network shown in fig.

(ii) Check the results obtained using MATLAB.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 25

Line data:

From To R X B/2

Bus Bus

1 2 0.10 0.20 0.02

1 4 0.05 0.20 0.02

1 5 0.08 0.30 0.03

2 3 0.05 0.25 0.03

2 4 0.05 0.10 0.01

2 5 0.10 0.30 0.02

2 6 0.07 0.20 0.025

3 5 0.12 0.26 0.025

3 6 0.02 0.10 0.01

4 5 0.20 0.40 0.04

5 6 0.10 0.30 0.03

Program:

% Program to form Admittance and Impedance Bus Formation....

clc

fprintf('FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRIX\n\n')

fprintf('Enter linedata in order of from bus,to bus,r,x,b\n\n')

linedata = input('Enter line data : ');

fb = linedata(:,1); % From bus number...

tb = linedata(:,2); % To bus number...

r = linedata(:,3); % Resistance, R...

x = linedata(:,4); % Reactance, X...

b = linedata(:,5); % Ground Admittance, B/2...

z = r + i*x; % Z matrix...

y = 1./z; % To get inverse of each element...

b = i*b; % Make B imaginary...

nbus = max(max(fb),max(tb)); % no. of buses...

nbranch = length(fb); % no. of branches...

ybus = zeros(nbus,nbus); % Initialise YBus...

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 26

% Formation of the Off Diagonal Elements...

for k=1:nbranch

ybus(fb(k),tb(k)) = -y(k);

ybus(tb(k),fb(k)) = ybus(fb(k),tb(k));

end

% Formation of Diagonal Elements....

for m=1:nbus

for n=1:nbranch

if fb(n) == m | tb(n) == m

ybus(m,m) = ybus(m,m) + y(n) + b(n);

end

end

end

ybus = ybus % Bus Admittance Matrix

zbus = inv(ybus); % Bus Impedance Matrix

zbus

Result:

Thus, the bus admittance and impedance matrices for the given power system network were obtained using

MATLAB.

Outcome:

By doing the experiment, the students can understand the concepts of MATLAB programming in solving bus

admittance and impedance matrix.

Application:

Bus admittance matrix is used for load flow analysis

Bus impedance matrix is used to short circuit study

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 27

1. What is meant by singular transformation method?

The matrix formed by graph theory.

2. What is meant by inspection method?

The admittance matrix calculated directly is called inspection method.

3. What is meant by bus?

Bus is junction point of transmission line.

4. What are the components of a power system?

Generator, Transformer, transmission line, load

5. What is meant by single line diagram?

Power system represented in simple graphical view

6. How are the loads represented in reactance or impedance diagram?

loads represented in reactance diagram resistor with reactor.

7. What are the different methods to solve bus admittance matrix?

Inspection method, direct method

8. What are the elements of the bus admittance matrix?

Reactance

9. What are the elements of the bus impedance matrix?

Resistor and reactor

10. What are the methods available for forming bus impedance matrix?

1. Bus building algorithm

2. using y bus

11. Define per unit value.

Per unit is defined as the ratio of actual value to base value

12. What are the advantages of per unit computations?

The manufacture is used as common value

It is easy to understand.

Viva - voce

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 28

Expt. No. 5: LOAD FREQUENCY DYNAMICS OF SINGLE AREA

POWER SYSTEM

Aim:

To become familiar with modeling and analysis of the frequency and tie-line flow dynamics of a single area power

system with and without load frequency controllers (LFC) and to design better controllers for getting better responses

Software required:

MATLAB / SIMULINK

Theory:

Active power control is one of the important control actions to be performed in the normal operation of the system

to match the system generation with the continuously changing system load in order to maintain the constancy of

system frequency to a fine tolerance level. This is one of the foremost requirements in proving quality of power

supply. A change in system load causes a change in the speed of all rotating masses (Turbine ? generator rotor

systems) of the system leading to change in system frequency. The speed change form synchronous speed initiates

the governor control (primary control) action result in the entire participating generator ? turbine units taking up the

change in load, stabilizing system frequency. Restoration of frequency to nominal value requires secondary control

action which adjusts the load - reference set points of selected (regulating) generator ? turbine units.

Procedure:

1. Enter the command window of the MATLAB.

2. Create a new Model by selecting File - New ? Model.

3. Pick up the blocks from the simulink library browser and form a block diagram.

4. After forming the block diagram, save the block diagram.

5. Double click the scope and view the result.

Exercise:

1. An isolated power station has the following parameters:

Turbine time constant, ? T = 0.5sec, Governor time constant, ? g = 0.2sec

Generator inertia constant, H = 5sec, Governor speed regulation = R per unit

The load varies by 0.8 percent for a 1 percent change in frequency, i.e, D = 0.8

(a) Use the Routh ? Hurwitz array to find the range of R for control system stability.

(b) Use MATLAB to obtain the root locus plot.

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 29

(c) The governor speed regulation is set to R = 0.05 per unit. The turbine rated output is 250MW at nominal

frequency of 60Hz. A sudden load change of 50 MW (?P L = 0.2 per unit) occurs.

(i) Find the steady state frequency deviation in Hz.

(ii) Use MATLAB to obtain the time domain performance specifications and the frequency deviation step response.

Without integral controller: (simulink block diagram)

With integral controller: (simulink block diagram)

Exercise: 1

An isolated power system has the following parameter:

Turbine rated output 300 MW, Nominal frequency 50 Hz, Governer speed regulation 2.5 Hz per unit MW, Damping

co efficient 0.016 PU MW / Hz, Inertia constant 5 sec, Turbine time constant 0.5 sec, Governer time constant 0.2 s,

Format No. FirstRanker/Stud/LM/34/Issue:00/Revision:00 30

Viva - voce

Load change 60 MW, The load varies by 0.8 percent for a 1 percent change in frequency, Determine the steady

state frequency deviation in Hz

(i) Find the steady state frequency deviation in Hz.

(ii) Use