Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 7th Sem 2171707 Industrial Drives And Control Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?VII (NEW) EXAMINATION ? WINTER 2020
Subject Code:2171707 Date:19/01/2021
Subject Name:Industrial Drives and Control
Time:10:30 AM TO 12:30 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) Why do we require drive circuit to run the motor?
03
(b) Explain the effect of DC motor back emf on performance of drive circuit.
04
(c) With appropriate block diagram, explain cascade control in DC motor
07
closed loop control.
Q.2 (a) Discuss the selection criteria for electric motor drive
03
(b) Explain the electro-mechanical modeling of DC motor drive.
04
(c) Explain four quadrant operation of DC motor drive using chopper circuit.
07
Q.3 (a) Where do we require chopper based drive?
03
(b) Draw and explain closed loop control of chopper drive.
04
(c) Give output voltage waveform of full wave controlled rectifier, driving
07
DC shunt motor, for 30 degree firing angle.
Q.4 (a) Draw any appropriate circuit to convert line voltage into chopper input
03
voltage of 100 VDC.
(b) Explain the principle of operation of chopper in brief.
04
(c) Give output voltage waveform of full wave controlled rectifier, driving
07
DC shunt motor, for 60 degree firing angle.
Q.5 (a) Draw basic voltage inverter circuit with resistive load
03
(b) Draw practical sources for voltage source inverter nd current source
04
inverter.
(c) Explain with necessary circuit diagram, the working of modified half
07
bridge Macmurray voltage source inverter
Q.6 (a) Explain why power factor is high in induction motor ?
03
(b) With block diagram explain induction motor speed control with variable
04
speed PWM.
(c) What is the limitation of cyclo converter based induction motor drive ?
07
Suggest and explain any other scalar control method for induction motor.
Q.7 (a) Draw torque v/s angular displacement characteristic curve for 3 phase VR
03
step motor
(b) What is micro stepping in step motor? Why is it required?
04
(c) With necessary circuit diagram and waveforms, explain recovery at high
07
voltage drive for step motor.
1
Q.8 (a) Draw torque v/s angular displacement characteristic curve for 4 phase PM
03
step motor
(b) List out essential components of DC servo control
04
(c) With necessary circuit and waveforms, explain zener + resistance type and
07
capacitor suppression drive for step motor.
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This post was last modified on 04 March 2021