GTU 3150911 Power System- II Summer 2023 Question Paper & PDF

How capacitance present between the line and ground is taken into account while modelling medium length transmission line?

An overhead 3-φ short transmission line delivers 5000 kW at 22 kV at 0.8 pf lagging. The resistance and reactance of each conductor is 4Ω and 6Ω respectively. Determine

Prove that per-unit impedance of a transformer is same whether it is computed from primary or secondary side

Distinguish between symmetrical and unsymmetrical faults giving appropriate examples

In a 3-φ, 4-wire system, the currents in phase A,B and C under abnormal loading conditions are given by Ia = 100/30° A, Ib = 50/300° A, Ic = 30/180° A. Calculate the positive and zero sequence currents Ia1, Ia0 and return current in the neutral wire.

Using rigorous solution method, derive the expression for ABCD constants of a long transmission line in terms of hyperbolic sine and cosine terms

Show that symmetrical component transformation is power invariant

A 100 MVA, 33 kV, 3-φ generator has a reactance of 15%. The generator is connected to the motors through a transformer and transmission line as shown in figure 1. Motors have rated inputs of 40 MVA, 30 MVA and 20 MVA with 20% reactance each. Draw the per-unit reactance diagram. Assume a base of 100 MVA and 33 kV in generator circuit.

Draw the zero sequence reactance diagram of transformers having the following connections

A 3-φ short transmission line has a resistance of 5Ω per phase and inductive reactance of 15Ω per phase. If the sending end and receiving end voltage are 140 kV and 132 kV respectively, find the horizontal and vertical co-ordinate of the receiving end power circle diagram (i.e. centre of the circle) in MW and MVAR

Derive the expression for fault current for a double line to ground fault at the generator terminals. Also discuss how sequence networks are connected for L-L-G fault.

A wave travels over a line and enters the cable. The surge impedance of overhead line and cable are 400Ω and 40Ω. Find the value of refracted voltage wave as percentage of incident voltage wave

Explain in brief the different methods of voltage control employed in power systems

Explain the phenomena of arcing grounds in an isolated neutral systems. Discuss why it can cause severe overvoltages in a power system.