Fast Method for the Iron Loss Prediction in Inverter-Fed Induction Motors

In this paper, an easy method for the iron loss prediction in pulsewidth-modulation (PWM) inverter-fed induction motors is presented. The method was initially proposed and validated for the prediction of iron losses in a nonoriented soft magnetic material with PWM supply. 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 a motor can be obtained too. The method requires the separation of the iron losses in the hysteresis and the eddy current components with a sinusoidal supply, plus the average rectified and rms values of the applied PWM voltage. The proposed method has been proved on an induction motor prototype that is able to provide a good accuracy in the iron loss measurement. The comparison between the measured and predicted iron losses with PWM supply has shown an excellent agreement with an error lower than 5%, confirming the method validity.