A three-phase round rotor synchronous generator, rated 16kV and 200MVA, has negligible losses and synchronous reactance of 1.65 per unit. It is operated on an infinite bus having a voltage of 15kV. The internal emf Ei and the power angle Delta of the machine are found to be 24kV (line-to- line) and 27.4o, respectively. a) Determine the line current and the three-phase real and reactive power being delivered to the system. b) If the mechanical power input and the field current of the generator are now changed so that the line current of the machine is reduced by 25% at the power factor of part a, find the new internal emf Ei and the power angle Delta. c) While delivering the reduced line current of part b, the mechanical power input and the excitation are further adjusted so that the machine operates at unity power factor at tits terminals. Calculate the new values of Ei and Delta.