b) Why stator voltage control is suitable for speed control of induction motors in fan and pump drives.

(2
mark)

a) Using suitable Drive, Explain the Sub synchronous and super synchronous modes of operation of a three
phase wound rotor induction motor.

(8 mark)

0) Using block diagram, explain the implementation of direct vector control of three phase induction motor
with respect to rotor flux orientation

(4mark)

a) Distinguish between Direct and Indirect vector control scheme and mention the advantages of indirect
vector control.

(Smark)

b) Using block diagram of indirect vector controller, describe the implementation of vector control of VSIfed
three phase induction motor drive.

(7 mark)
PART -3

a) Draw and explain the performance characteristics of synchronous motor drive in constant torque region
and field weakening region.

(3 mark)

b) Using block diagram, explain V/F method of speed control of fed Three Phase Synchronous Motor drive.
Explain clearly how the motor speed should be able to track the command frequency, without loosing
synchronism.

(6 mark)

a) Explain the working of a self controlled load commutated inverter fed synchronous motor drive for speed
control applications.

(5 mark)

b) Using block diagram, explain how closed loop speed control operation could be achieved in the above
synchronous motor drive.

(4 mark)

a) Obtain the dynamic machine model of a permanent magnet BLDC motor and derive the equation for
electromagnetic torque developed.

(5 mark)

b) Draw and explain the Current Control Loop Configuration for the speed control of a BLDC Motor

drive.

(4 mark)