Power System Analysis And Simulation — Summer 2019

State and advantages of per unit system.

Derive the ABCD constants for nominal –π representation of medium length transmission line.

Explain Sub-Transient, Transient and Steady State reactance of synchronous machine.

Write a brief note on selection of circuit breaker.

A 50 Hz transmission line 300 km long has a total series impedance of (40 + j 125) ohms and a total shunt admittance of 10-3 mho. The receiving end load is 50 MW at 220 kV with 0.8 lagging power factor. Find the sending end voltage and current using exact method.

Derive the relationship between symmetrical components of line and delta currents.

Agenerator is rated 1000 MVA, 11 KV. Its star connected winding has reactance of 0.9 PU Find (1) Ohmic value of reactance (2) If the generator is working in a circuit for which the base values are specified as 250 MVA, 22 KV, find out its PU reactance on the specified base.

Derive the equation of the capacitance of a three phase line with equilateral spacing.

Explain ‘type 2 modification’ of Zbus building algorithm.

Derive an expression for the fault current for a double-line fault as an unloaded generator.

Asynchronous generator is rated 25 MVA, 11 kV. It is star connected with neutral point solidly grounded. The generator is operating on no-load at rated voltage. Its reactances are X’’ = X2 = j0.20 pu and X0 = j0.08 pu. Calculate the symmetrical sub transient line current for (i) LG fault (ii) LL fault (iii) LLG fault (iv) LLL fault

Explain the need of neutral grounding of system. Describe any one method of neutral grounding.

Discuss corona formation phenomenon.

Derive the equation for attenuation of a travelling wave.

A 500 kV, 2µS, rectangular surge travels along the line which is terminated by a capacitance of 2500 pF. Determine the voltage across the capacitance and the reflected voltage wave if the surge impedance is 400Ω.1

What is bus impedance matrix? How it is useful in symmetrical fault analysis?

Briefly explain the importance of power circle diagrams. Draw and explain the receiving end circle diagram for a transmission line.