A symmetrical short circuit is suddenly applied to a synchronous generator on open circuit, terminal voltage 1.0 p.u. The initial peak values of the oscillogram of the short circuit current during the sub-transient, transient and steady state periods are 8.0 p.u., 5.7 p.u. and 1.8 p.u. respectively.
a. Neglecting resistance, determine the synchronous, transient and sub-transient reactances.
b.If the machine is delivering 1.0 p.u. current at 0.8 power factor lagging at the rated terminal voltage when the short circuit is applied, calculate the new sub-transient, transient and steady state currents.