Generator model for power system studies

Modelling of generators for power systems studies is a difficult task, Uncertainties surrounding the choice of equivalent circuit and parameter measurement are compounded by the effects of saturation, whereby machine reactances vary with changes in voltage and current. The authors address these problems. A method of modelling is described involving the step by step solution of differential equations based on a simple d-q equivalent circuit, with damping represented by a single element in each axis. The equivalent circuit parameters and their saturation characteristics are derived using semi-empirical curve fitting techniques from the results of standard works tests