13 a)
b)

14 a)
b)

15 (a)

(b)

G7908 Pages: 2

current. Ratio of pole are 10 pole pitch is 0.67.

Distinguish between cylindrical pole and salient pole construction,
Determine the main dimensions of a 2500 KVA 187.5 rpm. 50112 3 phase 3 (7)
kV, salient pole synchronous generator. The generator is to be a vertical, water
Wheel type. The specilig magnetic loading is 0.6 wh/mm? and the specific
electric loading is 34000۸۸7. Use circular poles with ratio of core length to

Pole pitch= 0.05. Specify the type of pole construction used if the run away

speed is about 2 times the nornial speed,

Explain the design procedure of interpoles in DC machines? (5)
Determine the main dimensions of a 500 kVA, 50112 3 phase alternator to ಗ... (5)
at 375 rpm. The average air gap flux density is 0.55wb/mm?’, the specific

electric loading is 25000A/m. The peripheral speed should not exceed
35m/sec.
PART D

Answer any ۱۷۷ full questions, each carries 10 marks.
With all details of the various parameters including the units derive the output (5)
equation of a 3 phase squirrel cage induction motor.
Design the main dimensions of a 25 kW, 3 phase. 415V, 50 Hz, 14752൩ (5)
squirrel cage induction motor having an efficiency of 85 % and full load power
factor of 0.86. Assume Ba, = 0.51, ac = 28000A/m. The rotor peripheral

velocity is 25 m/s at synchronous speed.
Explain how finite element method is used for analysis of electrical machines. ( 6)

List out the advantages of FEM based methods over conventional design (4)
procedures. ۱
Explain the procedure for separation of D and L from 1271, product while (൭)
designing induction motors.

8100 (5)

What is computer aided design’? How does it help in designing electrical

machines?
a of ok %

Scanned with CamScanner