Download PTU (Punjab Technical University) B.Tech (Bachelor of Technology) / BE (Bachelor of Engineering) 2021 January EE 9th Sem 75642 Power System Analysis Previous Question Paper
Total No. of Pages : 02
Total No. of Questions : 18
B.Tech. (EE) PT (Sem.?9)
POWER SYSTEM ANALYSIS
Subject Code : BTEE-801
M.Code : 75642
Time : 3 Hrs. Max. Marks : 60
INST RUCT IONS T O CANDIDAT ES :
1 .
SECT ION-A is COMPULSORY cons is ting of TEN questions carrying TWO marks
each.
2 .
SECT ION-B c ontains F IVE questions c arrying FIVE marks eac h and s tud ents
have to atte mpt any FOUR q ues tions.
3 .
SECT ION-C contains THREE questions carrying T EN marks e ach and s tudents
have to atte mpt any T WO questio ns.
SECTION-A
Write briefly :
1.
What is meant by fault level?
2.
What are the approximates in short circuit analysis?
3.
What are the current limiting reactors?
4.
Name the fault which do not have zero-sequence currents flowing.
5.
Draw the zero-sequence network for a star connected generator earthed through a
resistance R.
6.
Write the general expression for complex power injected by the source into ith bus of a
power system.
7.
What is meant by acceleration factor in load flow solution and its best value?
8.
Define steady state stability.
9.
What is meant by power angle curve?
10. Write swing equation for single machine system.
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SECTION-B
11. Explain the positive, negative and zero sequence components. Also mention its
significance in Power System Analysis. Discuss the limitations of sequence components.
12. A single phase transformer is rated 100kVA, 11/0.4 kV. Its leakage reactance is 0.15
when referred to low voltage side. Determine its leakage reactance in percent and per
unit.
13. What are the causes of unsymmetrical faults in power system? Derive an expression for
the fault current for a single line to ground fault.
14. Discuss the advantages of using Ybus model of power system network for load flow
analysis.
15. A 100 MVA synchronous generator operates on full load at a frequency of 50 Hz. The
load is suddenly reduced to 50 MW. Due to time lag in governor system, the steam valve
begins to close after 0.4 second. Determine the change in frequency that occur in this
time. Given H = 5 kW- s/kVA f generator capacity.
SECTION-C
16. A generator operating at 50 Hz. Delivers 1 pu power to an infinite bus when a fault
occurs and reduces the maximum power transferable to 0.4 pu. The maximum power
transferable before the occurrence of fault was 1.75 pu. The maximum power transferable
after clearance of the fault is 1.25 pu. Compute critical clearing angle.
17. Derive the load flow algorithm using Neuton Raphson method with flow chart and
discuss the advantages of the method.
18. A 3phase star connected alternator is rated 30 MVA, 13.8 kV and has the following
sequence reactance values: X1 = 0.25 pu; X2 = 0.35 pu; and X0 = 0.10 pu. The neutral of
the alternator is solidly grounded. Determine the alternator line currents when a double
line to grounds fault occurs on its terminals. Assume that the alternator is unloaded and is
operating at rated voltage when the fault occurs.
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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This post was last modified on 26 June 2021