A Dynamic Circuit Model for Pole Amplitude Modulated Induction Motors

A dynamic circuit model for a pole amplitude modulated three phase, induction motor is developed. The only parameter values required, in addition to the standard ones for ordinary induction motors, are an equivalent rotor slot depth to model skin effect in the bars and the distribution of rotor resistance and leakage reactance between the endrings and bars. Characteristics predicted by the model are compared with those measured on a 6/8-pole and a 6/4-pole machine. The effects of the mmf harmonics are correctly modelled, the difference between computed and measured torques being consistent with stray loss effects.