An optimal pulse width modulation method for high-speed permanent magnet synchronous motor

Abstract

This paper proposes an optimal pulse width modulation (PWM) method for high-speed permanent magnet synchronous motor (PMSM), which combines the proposed fundamental voltage component invariance (FVCI) PWM method ensuring the same voltage and current fundamental components as the command waveforms, with the minimum current harmonic PWM method. First, the paper regards the third harmonic injection PWM (THIPWM) with 25% third harmonic as the minimum current harmonic PWM method, and proposes a simple algorithm to generate the third harmonic based on the three-phase fundamental voltage waves. Then the paper proposes a FVCI-PWM method, which ensures that the PWM waveform has the same fundamental component as the command sinusoidal voltage waveform without current closed-loop control. The simulation and experimental results upon the 60000rpm PMSM are carried out finally to verify the effectiveness of the proposed PWM method.