An advanced induction machine model for predicting inverter-machine interaction

The classical qd induction motor model typically used in drive simulations is very inaccurate in predicting machine performance, except perhaps for the fundamental component of the current and average torque near rated operating conditions. Predictions of current and torque ripple are often in error by a factor of two to five. This work sets forth an induction machine model specifically designed for use with inverter models to study machine-inverter interaction. Key features include stator and rotor leakage saturation as a function of magnetizing flux, distributed effects in the rotor circuits, and a highly computationally efficient implementation. The model is considerably more accurate than the traditional qd model, particularly in its ability to predict switching frequency phenomena such as current and torque ripple. The predictions of the proposed model are compared to those of a standard qd induction motor model and to experimental measurements for a 50 hp induction motor drive.