Analysis of PWM induced loss rise in a 5-kW induction machine

An industrial electrical machine prototype is measured with a pulse-width-modulated voltage supply using different switching frequencies; 4, 8, 12 and 16 kHz when the motor is operating at 25 and 40 Hz fundamental frequencies. Typically, the electrical machine losses decrease as a function of the switching frequency and in this case a similar behavior is reported in careful measurements. The loss distribution at different carrier frequencies is further explored using multi-sliced FE-model to check the trend of the measured losses.