PTU B.Tech EE Engineering 5th Semester May 2019 70567 POWER SYSTEM II 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. (Electronics & Electrical) (2013 Onwards)
B.Tech. (Electronics & Electrical) (2011 Onwards) (Sem.?5)
POWER SYSTEM ? II
Subject Code : BTEEE-502
M.Code : 70567
Time : 3 Hrs. Max. Marks : 60
INSTRUCTIONS 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
1.
Answer briefly :


a. Write any four application of isolator.

b. Define the following terms : pick-up, reset.

c. Define the theory of arc interruption.

d. Write any four application of negative sequence relay.

e. Define the impulse gap and its advantages.

f. Define the surge Absorber.

g. Define the line trap unit and coupling unit.

h. Write any two functions of Metal oxide arrestor.

i. Write any four dielectric property of SF6 gas.

j. Write any four differences between DC and AC networks.

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SECTION-B
2.
Name the parts and explain the operation of the circuit breaker during the fault clearing.
3.
Explain the principle, types and application of thermal relay.
4.
In 50 Hz. Overhead line the capacitance of one line to earth was 1.5 micro farad. It was
decided to use an earth fault neutralizer. Calculate the reactance neutralize the
capacitance of :

a. 100% of length line

b. 90% of length line

c. 95% of length line
5.
Explain the phase comparison method of carrier current protection.
6.
Explain the Buchholz relay with reference to limitations and difficulties.

SECTION-C
7.
A 30 MVA, 11.5 KV, star- delta power transformer is to be protected by differential
protection. The high voltage side phase lags behind low voltage side phase by 30?.
Formulate the complete differential protection for the transformer by selecting CT ratios,
CT connections. The continuous current carrying capacity of restraining coils of the
differential relay should not exceed 5 Amp. CT ratio is 3000/5 on 11.5 Kv side.
Determine CT ratio on 69 kV side.
8.
Shows in detail, the protection arrangement of a 60MW generator provided with :

a. Differential protection.

b. Back-up over current protection through faults.
9.
Draw the layout of substation and explain its main equipment in detail.



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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