Seat No.: ______Enrolment No.______

GUJARAT TECHNOLOGICAL UNIVERSITY BE - SEMESTER–VI (NEW) EXAMINATION – WINTER 2017 Subject Code: 2162404 Date: 03/11/2017 Subject Name:Industrial Drives & Control-I Time:02:30 PM TO 05:00PM Total Marks: 70 Instructions: 1. Attempt all questions. 2. Make suitable assumptions wherever necessary. 3. Figures to the right indicate full marks.

Q.1 (a) Is Ward Leonard Control technic existing? Where? 03 (b) Discuss Ward Leonard Control technic. 04 (c) Discuss types of motor duty and selection of motor rating. 07 Q.2 (a) Draw and explain basic block diagram of DC Drive. 03 (b) Enumerate the benefits of Power Electronics Drive over old conventional DC Motor 04 control strategy. (c) Derive the formula of speed and torque for DC Series motor for single phase semi- 07 converter and full converter operation. Also draw the speed -torque characteristics. OR (c) Explain the operation of single phase semi-converter circuit for DC Series Motor 07 with discontinuous current condition at α = 30o. Draw various wave-forms. Q.3 (a) Explain steady state & transient stability of electric drive. 03 (b) Discuss transfer function of field controlled . 04 (c) Explain the operation of 1-phase full converter with conventional current condition 07 having high speed and high inductive load for separately excited DC motor at α = 45o. Also draw various wave-forms. OR Q.3 (a) Explain braking of separately excited dc Motor using chopper circuit. 03 (b) Draw various waveforms of separately excited dc Motor braking using chopper 04 circuit. (c) Derive the equation of speed and torque for single phase full converter separately 07 excited DC shunt motor. Also draw speed-torque characteristics for the same. Q.4 (a) Enlist the importance of PI control for DC Drive. 03 (b) Brief the Servo requirement. 04 (c) Compare P, PI & PID controller. 07 OR Q.4 (a) Discuss Phase Locked Loop control of DC drive. 03 (b) Write short-note on micro-computer control of DC drive. 04 (c) Explain Permanent Motor Drive. 07 Q.5 (a) Explain multi-phase chopper circuit. 03 (b) Enlist advantages and disadvantages of multi-phase chopper circuit. 04 (c) Discuss chopper control technic used in Traction. 07 OR Q.5 (a) Write merit & demerit of dual converter for non-circulating current. 03 (b) Write advantages and disadvantages of dual converter having circulating current. 04 (c) Discuss transfer function of armature controlled dc motor. 07

*************

1