Iron losses analysis with different supply techniques in high poles number induction motors for automotive applications

High poles number in induction motors makes the iron losses analysis even more important than in conventional induction motors. A high pole number induction motor prototype, for automotive applications, has been designed and tested. This motor has been designed to be installed between the internal combustion engine and the gearbox, to operate either as starter or alternator. The iron losses in the inverter supplied motor have been experimentally measured, analyzed and compared with those generated in the case of sinusoidal supply. The iron losses variations related to the inverter supply conditions (PWM switching frequency and modulation index) have been determined, with the aim of helping the proper choice of the supply system and of improving the motor design.