Power System Engineering-II SPPU Endsem Question Paper May 2025
All 8 questions from this SPPU endsem paper, as printed. Read them here or open the PDF.
- Subject code
- 303148
- Pattern
- 2019 pattern
- Exam
- Endsem
- Session
- May 2025
- Max. marks
- 70
- Time
- 2½ Hours
- Semester
- VI
- Paper code
- [6403]-68
Printed for: T.E. (Electrical)
Instructions to the candidates
- Solve Q1 or Q2, Q3 or Q4, Q5 or Q6 and Q7 or Q8.
- Use of calculator is allowed.
- Assume suitable data if necessary.
Questions
Q1
- a)[8]
Show that in transformer the per unit impedance of referred to primary and secondary is same.
Also asked:Nov 2024
- b)[8]
This part has equations that don’t show as text. Open the PDF to read it.
OR- a)
Q2
- a)[8]
i) The transmission line impedance is 0.1 + j0.2 Ohm/km. If the length of line is 150km, what is the per unit impedance of the line on the base of 200MVA, 10kV? ii) The impedance of a 200MVA, 10kV/200kV transformer referred to primary is (2 + j4) Ohm. What is the per unit impedance of the transformer referred to secondary? iii) The per unit base on primary side of the transformer is 100MVA, 10kV. The rating of the transformer is 150MVA, 11kV/220kV. What is the base MVA and kV to be taken on secondary side of the transformer? iv) A 100MVA, 11 kV alternator has reactance 10% on its own rating. What is the percentage reactance of alternator on 50MVA, 22kV base?
- b)[8]
Derive the generalize power flow equations for “ n ” bus power system. 2
- a)
Q3
- [18]
Let all phases of an alternator is short circuited at its terminal:
Also asked:Nov 2025
- a)[3]
Draw the waveform of fault current showing sub transient, transient and steady state period.
Also asked:Nov 2025
- b)[3]
From above diagram comment on time period sub transient, transient and steady state period.
Also asked:Nov 2025
- c)[3]
Draw the reactance diagram and write its formula for sub transient, transient and steady state period.
Also asked:Nov 2025
- d)[3]
If the damper winding reactance is j0.1 pu, field winding reactance is j0.2 pu, armature reactance is j0.3 pu and leakage reactance is j0.5 pu. Calculate sub-transient, transient and steady state reactance.
Also asked:Nov 2025
- e)[3]
Justify that the fault current under sub transient period is more that transient and steady state period.
Also asked:Nov 2025
ORQ4
- a)[8]
Show that when an alternator (or RL circuit) is shorted at its terminal derive the formula for maximum possible fault current to be supplied by the alternator?
- b)[10]
Determine the fault current and fault MVA when the three phase fault is occurred at point F in following: i) Draw per unit impedance diagram with generator 1 rating as a base. [3] ii) Find the per unit impedance upto fault point. [2] iii) Fault current in kA. [3] iv) Fault current supplied by each generator in kA. [2] 3
- a)
Q5
- a)[9]
Derive the equation of fault current in case of LLG fault.
- b)[9]
This part has equations that don’t show as text. Open the PDF to read it.
OR- a)
Q6
- a)[9]
Draw the zero sequence impedance diagram for following connections of transformer i) Delta-Star ii) Star-Star secondary neutral with solid ground iii) Delta-delta
- b)[9]
This part has equations that don’t show as text. Open the PDF to read it.
- a)
Q7
- a)[9]
Draw the single line diagram of a HVDC system showing all components with proper labels. Explain the working of any three components used in HVDC transmission.
- b)[9]
Write a short note on Monopolar and Bipolar HVDC transmission line.
OR- a)
Q8