2-FACTOR SATURATION MODEL FOR SYNCHRONOUS MACHINES WITH MULTIPLE ROTOR CIRCUITS

It is generally felt that no major accuracy breakthrough in predicting the steady-state and transient performance of synchronous machines co uld be achieved without taking proper account of the iron saturation e ffects as well as eddy current losses. Although the two issues were of ten treated separately in the past, this paper attempts to unite them by developing a general model covering both the main-path magnetic sat uration and frequency effects in the dynamic equations. Mathematical a nalysis in the d-q space pinpoints cross-saturation coupling which, a priori, does not seem to be symmetrical for salient-pole machines. Yet the model is theoretically sound, since it fulfills at least the phys ical constraints using energy balance principles, Some test points fro m a 555-MVA turbine generator are used for an initial assessment the m odel's capability to predict the field current and internal angle for various loading conditions.