High Frequency Modelling of Permanent Magnet Synchronous Machine

Abstract

This paper addresses the modelling of PMSM under high frequency PWM control. The high frequency components of input voltage have different responses in terms of induced current and iron losses, due to eddy currents in the magnets, phase conductors and in the core lamination. Both inductance and HF iron loss behavior of the machine were investigated through experiment, modelled, and reproduced by circuit simulation. Inductance is treated separately for low frequency and high frequency components to build the current response of the machine. HF iron losses are determined for each HF cycle individually, according to peak-to-peak HF current. The configuration of the model can be realized either from locked rotation tests or from Finite Element Analysis. The model is suited for the optimization of control strategy with respect to losses, including adaptation of switching frequency or over-modulation.