A VSFPWM Strategy for High Frequency Torque Ripple Control of PMSM Based on Stator Flux Ripple Prediction

Abstract

Vector-controlled AC motor drives utilize pulse width modulation (PWM) to synthesize the desired output voltage of the voltage source inverter (VSI). In space vector PWM (SVPWM) techniques, the average realization of the space vector applying the volt-sec balance principle results in an instantaneous error voltage that generates high frequency torque ripple. It may lead to an increase in motor vibration and acoustic noise. This article presents a high frequency torque ripple prediction model based on stator flux ripple and proposes a targeted designed variable switching frequency PWM (VSFPWM) strategy to diminish high frequency torque ripple. The switching frequency is dynamically adjusted according to the peak value of the predicted stator flux ripple to mitigate high frequency torque ripple. In contrast to existing strategies, the strategy outlined in this article directly suppresses high frequency torque ripple, thus remaining unaffected by inaccurate motor parameters. Additionally, due to the introduction of the power factor angle, the proposed strategy can better adapt to the full speed range operating conditions of the motor. Detailed simulations and experiments are provided to validate the effectiveness of the proposed strategy.