A General Model to Predict the Iron Losses in PWM Inverter-Fed Induction Motors

Abstract

This paper presents an accurate and efficient method for predicting the iron losses in pulsewidth modulation (PWM) inverter-fed induction motors. The method was initially proposed for the prediction of iron losses in a nonoriented soft magnetic material with the same supply conditions. The proposed method requires the separation of the iron losses in the hysteresis and eddy-current components and the average rectified and rms of the PWM voltage values. Starting from the iron losses measured with a sinusoidal supply and the PWM waveform characteristics, a fast and reliable prediction of the iron losses in the motor with the new voltage supply can be obtained. The proposed method has been proved on an induction-motor prototype capable of providing good accuracy in the iron-loss measurement. The comparison between the measured and predicted iron losses with the PWM supply has shown excellent agreement, confirming the validity of the method.