SYMMETRICAL FAULT CALCULATIONS – PART – 06 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

A 50 MVA, star connected 11kV synchronous generator is connected to a 50 MVA, 11 kV/132 kV , Delta/Star transformer, sub-transient reactance of the generator is 0.12 p.u on a 50 MVA base and the transformer reactance is 0.1 p.u reactance on the same base. The generator is unloaded when a symmetrical fault occurs at point A. Find the sub-transient symmetrical fault current on both sides of the transformer.