B B4B0102

Total Pages: 2
Reg No.: Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FOURTH SEMESTER B.TECH DEGREE EXAMINATION, JULY 2017
Course Code: EE202
Course Name: SYNCHRONOUS AND INDUCTION MACHINES (EE)

Max. Marks: 100 Duration: 3 Hours
PARTA
Answer all questions. Each carries 5 marks.
1 Enumerate various methods for minimising harmonics in alternators. (5)
2 What are the different methods of finding the voltage regulation of an alternator. (5)
3 Describe the slip test method for finding the Xaand Xq of synchronous machines. (5)
4 Explain the constructional details of a synchronous motor. (5)
5 Differentiate between the phenomenon cogging and crawling of an induction (5)
motor.
6 List the various methods adopted for braking of an induction motor. (5)
Compare induction generator with synchronous generator. (5)
8 With a sketch describe the principle of working of a shaded pole motor. (5)
PART ‏تا‎

Answer any two questions. Each carries 10 marks.
9 ஐ) Explain various types of armature winding of an alternator. (5)

0) Find the distribution and pitch factor of a 3, 4 pole, 24 slots alternator having its (5)
armature coils short pitched by one slot.
10 A 0.5 MVA, 1.1KV, 50 Hz, 30, star connected alternator has Ra and ‏ۂ‎ per phase (10)
as 0.1Q and 1.5Q respectively. Find its voltage regulation at different power factor
of (i) unity (ii) 0.9 lag and (111) 0.8 lead at full load.
11 A 22017 6 pole, 50 Hz, star connected alternator gave the following test results:- (10)

Field current
inA

Open circuit 29 172 232 | 261 | 284 | 300 | 310
line voltage in

Volts

ZPF test line 177 | 208 | 230
voltage

volts

SCC in A 6 32.4 | 40 | 46.3 | 59

Find % voltage regulation at full load current of 40A at power factor 0.8 lag by
(1) m.m.f method (ii)ZPF method. R,=0.06 Q /phase.

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