Problem: A 100MVA, 50Hz generator having a power factor of 0.8 lagging has an inertia
constant of 2MJ/MVA. The machine is initially operating in steady state at synchronous
speed, producing 1.0 per-unit real power. The initial value of rotor angle is 5°, when a
bolted there-phase to ground short circuit occurs at its terminals. Find the angular
displacement of the rotor at 0.02 seconds after the fault, assuming that the prime mover
input is maintained at 1.0 per-unit.
Problem: A power station consists of two synchronous generators A and B of ratings
250MVA and 500MVA with inertia constant 1.6 per-unit and 1.0 per-unit respectively on
their own base MVA ratings. Determine the equivalent per-unit inertia constant for the
complete system on 100MVA common base.