PTU B.Tech EE Engineering 5th Semester May 2019 70554 SYNCHRONOUS MACHINES Question Papers

PTU Punjab Technical University B-Tech May 2019 Question Papers 5th Semester Electrical and Electronics Engineering (EEE)-EE-Electrical Engineering

Roll No.
Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(EE)PT/(EE) (2011 Onwards)
B.Tech.(Electrical & Electronics) (2011 & 2012 Batch)
B.Tech. (Electrical Engineering & Industrial Control) (2012 Onwards)
(Sem.?5)
SYNCHRONOUS MACHINES
Subject Code : BTEE-501
M.Code : 70554
Time : 3 Hrs. Max. Marks : 60
INSTRUCTION TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.




SECTION-A
Q1 Answer briefly :

a. Define synchronous impedance of an alternator.

b. What is excitation voltage of an alternator?

c. Why damper winding is provided in salient pole synchronous motor?

d. Write the conditions of parallel operation of alternators.

e. What is a turbo alternator?

f. Define synchronous reactance.

g. What is salient pole type synchronous machine?

h. What is synchronous condenser?

i. What type of voltage is supplied to field of synchronous motor?

j. Define transient stability of synchronous machine.
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SECTION-B
2.
Draw and explain phasor diagram of a cylindrical rotor alternator at leading power factor
load.
3.
Draw and explain the phasor diagrams at lagging power factor for salient pole synchronous
motor.
4.
What is the necessity of computing voltage regulation of an alternator?
5.
Draw and explain internal and external characteristic of an alternator.
6.
Describe briefly the construction and application of a hysteresis motor.

SECTION-C
7.
Derive the expressions of electromagnetic power, reluctance power and total output power
of a salient pole synchronous generator based on its phasor diagram. Draw and explain the
power-angle characteristic for this machine.
8.
Describe the constructional features, working principle and applications of single- phase
reluctance motor.
9.
A 2200 V, 400 kW, 3-phase star connected synchronous motor has a synchronous
impedance of 0.3 + j3 ohm. Determine the excitation emf and the power angle if the motor
works at rated load at 0.8 power factor leading and with an efficiency of 94%.








NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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