The synchronous machine of Problem 13.3.2 is to be used as a motor. Determine the following:
(a) The exciter setting Vex for operation at rated conditions and a power factor of
(i) 0.866 lagging, and
(ii) 0.866 leading.
(b) Vex in part (a) for unity power factor and the same real power input as in part (a).
(c) The complex power absorbed by the machine in parts (a) and (b).
Problem 13.3.2
A three-phase, wye-connected, 2300-V, four pole, 1000-kVA, 60-Hz synchronous machine has a synchronous reactance Xs = 5 Ω, a field resistance Rf = 10 Ω, and an approximately linear magnetization characteristic (Ef versus If ) with a slope Kag = 200 Ω.
The machine is connected to a balanced three-phase ac system and is used as a generator. Determine the following:
(a) The rated stator current.
(b) The exciter setting Vex = If Rf for operating the machine at rated conditions, at a power factor of
(i) 0.866 lagging and
(ii) 0.866 leading.
(c) Vex in part (b) for unity power factor and the same real power output as in part (b).
(d) The complex power delivered by the generator to the system for parts (b) and (c).