# Download GTU B.Tech 2020 Summer 6th Sem 2160902 Power Electronics Ii Question Paper

Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Summer 6th Sem 2160902 Power Electronics Ii Previous Question Paper

Seat No.: ________
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER? VI EXAMINATION ? SUMMER 2020
Subject Code: 2160902 Date:26/10/2020
Subject Name: POWER ELECTRONICS ? II
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full mark0073.

MARKS
Q.1 (a) Classify AC converters.
03

(b) Explain requirement and function of gate driver circuit.
04

(c) Explain 3-phase inverter operation with 1800 conduction period.
07
Draw waveform of gate voltage, phase voltage and line voltage

Q.2 (a) Explain line commutation with waveforms.
03

(b) Explain concept of Pulse Width Modulation.
04

(c) Discuss effect of modulation index and carrier to modulation
07
frequency ratio on output of sine PWM technique.

OR

(c) Discuss concept of space vectors. How more output voltage can
07
be obtained in SVPWM compared to sine PWM technique.
Q.3 (a) Compare cycloconverter with matrix converter.
03

(b) Classify AC voltage controller. Draw waveform of single phase
04
full wave AC voltage controller with RL load and firing
angle=600.

(c) With circuit diagram explain basic principle of 3-phase
07
cycloconverter.

OR

Q.3 (a) Explain integral cycle control technique in brief.
03

(b) Explain selected harmonic elimination technique in brief.
04

(c) Can we control frequency of AC voltage controller? Justify the
07
answer by explaining operation of 3-phase full wave AC
controller.
Q.4 (a) Discuss various types of load that can be connected with power
03
electronics converters.

(b) What is R-L-E load? How is it different than R-L load?
04

(c) How three single phase cycloconverter can be operated as three
07
phase cycloconverter? Explain with necessary diagrams.

OR

Q.4 (a) Explain principle of current source inverter in brief.
03

(b) Explain single phase cycloconverter in brief.
04

(c) With diagram explain basic principle of matrix converter.
07
Q.5 (a) Explain load commutated cycloconverter in brief.
03

(b) Explain application of load commutated thyristors inverter.
04

(c) What is static Kramer drive? With circuit diagram explain its
07
operation.

1

OR
Q.5 (a) Discuss different region of speed torque characteristics of
03
induction motor.
(b) Explain in brief the self-controlled synchronous motor drive.
04
(c) Discuss V/f control technique of induction motor drive.
07

************
2