INFLUENCE OF THE INVERTER CHARACTERISTICS ON THE IRON LOSSES IN PWM INVERTER-FED INDUCTION-MOTORS

In this paper, the authors deal with the effects of the inverter chara cteristics on the iron losses increment in induction motors fed by pul sewidth modulation (PWM) controlled converters. Laboratory tests based on no-load input power measurement were carried out and in order to a void the influence of mechanical losses and rotor copper losses, diffi cult to be measured or computed, a special test bench with an unconven tional test device was employed. In particular the influence of the fo llowing inverter parameters are considered: modulation index, modulati on waveform, and switching frequency. Complete experimental results ar e presented and discussed.