A 3-phase synchronous generator rated at 75 MVA, 13.8 kV (L-L) is connected to a power system that has a Thevenin equivalent of j0.23 per unit at 1.0 per unit voltage. The synchronous reactance of the generator is j1.35 per unit. (Neglect armature resistance). Both per unit impedances were calculated on the base MVA rating of the generator .
a) Determine the maximum power in MW transferred to the system when the internal voltage (Eaf) of the generator is 1.10 pu.
b) Assuming that the generator is being operated with constant excitation, determine the power transferred to the system in MW when the power angle (δ) is adjusted to 30° and the Thevenin equivalent voltage drops to 0.9 per unit.