Power System Analysis II
EE 605
Question
2079 BhadraChapter 5: Unsymmetrical Faults on Power Systems5.1 Sequence Networks of Synchronous Generators
Draw the positive, negative and zero sequence impedance networks for the power system shown in figure below. Choose a base of 50 MVA, 220 kV in 50 Ω transmission lines and mark all reactances in pu. The ratings of the generators and transformers are:
Generator 1: 25 MVA, 11 kV, X'' = 20%
Generator 2: 25 MVA, 11 kV, X'' = 20%
Three-phase transformer (each): 20 MVA, 11 Y/220 kV, x = 15%
The negative sequence reactance of each synchronous machine is equal to its substransient reactance. The zero sequence reactance of each machine is 8%. Assume that the zero sequence reactances of lines are 25% of their positive sequence reactances.
[IMAGE: Figure from the original question paper with labels: Two j50 Ω lines; X = 5% at machine 1 rating; X = 5% at machine 2 rating]Add an answerChecking contribution access...