# Power system Analysis BE Fifth Sem

1. What is the need for system analysis in planning and operation of
power system?
2. How are the base value chosen in per unit representation of a
power system?
3. Draw the p equivalent circuit of a transformer with off nominal
tap ratio.
4. Define bus incidence matrix.
5. Mention two objectives of short circuit analysis.
6. Draw the zero sequence n/w of a star connected generator with
zero sequence impedance Zgo, when the neutral is grounded
through an impedance Zno.
7. What are the three classes of busses of a power system used in
power flow analysis? What are the quantities to be specified and
to be completed for each class during power flow solution?

8. Compare Gauss-Seidal method and Newton Raphson method
with respect to number of iterations taken for convergence and
memory requirement.
9. Define critical clearing time.
10. Write the power angle equation of a synchronous machine
connected to an infinite bus and also the expression for maximum
power transferable to the bus.
PART – B (5 x 12 = 60)
11. Explain single line and reactance diagram of a power system.
Also explain the per unit system of analysis power system
(or)
12. Explain in detail about the per phase analysis of symmetrical
three phase system.
13. Explain bus admittance and bus impedance matrix formation.
Discuss the p-equivalent circuit of transformer with off-nominal
tap-ratio.
(or)
14. Explain the modeling of generator, load and transmission line for
short circuit, power flow and stability.
15. Derive the formula for fault current, fault bus voltages and
current through the lines for a 3 phase symmetrical fault at a bus
in a power system using Z bus. State the assumptions made in
the derivation.
(or)
16. Explain the various objectives in short circuit analysis. Derive the
components of Z bus in sequence frame fault matrices.

17. (a) Discuss the procedure for representing a tap charging
transformer in the formation of system matrix (YBUS) for
(b) Explain the procedure for calculating line flows and line
flows and line losses.
(or)
18. For the network shown in fig. obtain the complex bus bar voltage
at bus 2 at the end of first iteration. Use Gauss-Siedal method.
Line impedance shown in fig are in per unit.
Given: Bus 1 in black bus with V1 = 1.00°
= Ð °
= Ð °
=
+ = − +
V o
Assume V o and
V
P jQ j and
o 1
: 1.02
| | 1.02
5.96 1.46
2
3
3
2 2
o
19. (a) Derive the swing equation of a synchronous machine
connected to an infinite bus.
(b) Deduce the condition of equal area criterion for transient
stability analysis.
(or)
20. Explain the step wise procedure of determining the swing curve
of a synchronos machine connected to infinite bus through a
double circuit transmission line using modified Euler’s method.