Technocrats Institute of Technology (Excellence)
MST II
EE 701- Electrical Drive
Total Marks: 70
Note:
Time: 3:00 Hr
(i) Attempt any five Question
(ii) All Question carry equal marks
Q 1 (a) Explain the operation of a single phase semi-controlled converter fed separately excited D.C
motor drive.
(b) Draw and explain block diagram of Electrical Drive uses in industrial application.
Q 2 (a) Derive an expression for the average output voltage of a 3φ semi-controlled converter
(b) Explain the operation of 1- φ fully controlled converter fed separately excited DC drive.
Q 3 (a) Explain the working of dual converter in all quadrants.
(b) Draw and explain the block diagram of closed loop operation of DC Drive.
Q 4 (a) Explain multi-quadrant operation of a separately excited DC motor drive fed from a dual
converter in detail.
(b) Explain with circuit diagram how regenerative braking is applied to
i) Separately excited dc motor and
ii) Series dc motor
Q 5 (a) Explain Cyclo-converter fed Induction motor Drive.
(b) Compare the operation of VSI and CSI fed Induction motor drive.
Q 6 (a) Discuss variable frequency control of IM drive. Draw the relevant speed torque characteristics
and derive the mathematical expression showing the relationship of max torque and operating
frequency.
(b) Show that a variable frequency induction motor drive develops at all frequencies the same torque for
a given slip-speed when operating at constant flux.
Q 7 (a) Explain the slip power recovery scheme of a three phase induction motor control. What are its
advantages and disadvantages?
(b) Describe self controlled synchronous motor drives in detail and compare with load commutated
inverter controlled drives.
Q 8 Write Short Notes of any of two:
i. Separate and self controlled synchronous motor
ii. Static Scherbius drive
iii.
Static Kramer Drive