SITARAMBHAI NARANJI PATEL INSTITUTE OF
TECHNOLOGY & RESEARCH CENTRE, UMRAKH
(Affiliated With Gujarat Technological University, Ahmedabad)
B.E. Semester-V ReMid Semester Exam
Electrical Engineering Department
Course: Power System - 2 (3150911)
Date: 21/10/2024
Time: 10:30 AM TO 11:30 AM
Marks: 30
Instructions: a) All questions are compulsory.
b) Make suitable assumptions wherever necessary.
c) Figure to the right indicates full marks.
Q.1(a)
Q.1(b)
Define active, reactive and apparent power in details.
CO1
CO1
U
E
03
07
Q.2(a)
Q.2(b)
What are the causes of overvoltage in power system?
CO4
What is a surge arrester? What is the difference between lightning arrester and surge arrester? CO4
Explain why the control of reactive power is essential for maintaining a desired voltage profile?
OR
Explain methods of reducing corona.
CO4
U
U
03
07
A
03
Define critical disruptive voltage. Derive necessary formula to calculate critical disruptive CO4
voltage.
Discuss: Transients on a transmission line during a short circuit.
CO3
Write a brief note on phase shift of symmetrical components in Y-Δ transformer banks
CO3
U
07
E
A
03
07
R
N
03
07
Q.2(a)
Q.2(b)
Q.3(a)
Q.3(b)
Q.3(a)
Q.3(b)
OR
Write a brief note on selection of circuit breakers.
CO3
Three 6.6 kv generator A, B & C each of 10% leakage reactance and MVA rating of 40,50 & 25 CO-3
as shown in figure. Each are interconnected by a tie bar through current liming reactors, each
of 12% reactance. A. three-phase feeder is supplied from the bus bar of generator A at a line
voltage of 6.6 kV. The feeder has resistance of 0.06 ohm/phase and inductive reactance of 0.12
ohm/phase. Estimate the maximum MVA that can be fed into a symmetrical short circuit at the
far end of the feeder.