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Max. Marks: 100

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11078 Pages: 2

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

SIXTH SEMESTER B.TECH DEGREE EXAMINATION(R&S), MAY 2019
Course Code: EE308

Course Name: Electric Drives

PARTA
Answer all questions, each carries5 marks.

What is an Electric Drive? Explain the function of each blocks with the help of a neat

block diagram.

Explain the armature voltage control and field weakening mode control of DC
separately excited motor drive system.

With a chopper circuit and waveforms explain the regenerative braking of a DC
motor drive.

Explain the speed control method of induction motor with stator voltage and also
state the disadvantages of this method.
Compare CSI fed IM drive with VSI fed IM drive
Explain the Park’s transformation.
With a block diagram explain the variable frequency control of SM drive in self-
control mode.
Explain the V/F control characteristics in torque-speed plane of a SM drive
PART B

Answer any two full questions, each carries10 marks.

a) What are the different components of a load torque? Explain each component in

detail.

b) Derive the mathematical condition to obtain the steady state stability of
equilibrium point.

With a neat sketch, explain the motoring and braking operation of three phase
fully controlled rectifier control of separately excited DC motor.

A 200 V, 875 rpm, 150 A separately excited ‏عل‎ motor has an armature resistance
of 0.0642. It is fed from a single phase fully controlled rectifier with an ac
voltage of 220 V,50Hz. Assuming continuous conduction, calculate

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Duration: 3 Hours

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