Impact of the inverter DC bus voltage on the core losses of a permanent magnet synchronous motor at constant speed

In this paper, the impact of the DC bus voltage on the core losses of a permanent magnet synchronous motor (PMSM) fed by a pulse-width modulation inverter is evaluated. Under constant speed operation, the modulation index decreases when the DC bus voltage increases. This modifies the harmonic content of the PMSM input voltage and then affects the motor core losses. The experimental results show that, for the conditions considered in this paper, the core losses are 1.8 times larger at the lowest modulation index than at the highest one.