VARIABLE PARAMETER INDUCTION MOTOR MODEL FOR POWER SYSTEM ANALYSIS.

The effect of frequency of the rotor currents on the parameters of the rotor of an induction motor plays a significant role in the determination of its transient performance. A digital computer model of a 3-phase stator-fed induction motor whose rotor resistance and reactance may be varied independently with rotor current frequency is considered. A simple method of varying the rotor parameters to correspond to those values obtained from experimental data is discussed. The results of start-up tests, short-circuit tests subsequent to attaining 90% rated speed and load tests are presented and the effect of large motor loads on stability is also investigated. It is the aim of this paper to present the computed effects of including the variations of the rotor parameters on the transient performance of an induction motor and their effects on the local generator during start-up, short-circuit and load tests.