Torque Ripple Reduction for PMSM based on PWM Pulse Merging Method for High Speed Range

Abstract

Permanent magnet synchronous motors (PMSMs) are widely used because of their high efficiency and lower energy consumption. However, the motor noise and the vibration caused by the torque ripple is a well-known problem because of an imperfect sinusoidal flux distribution. To reduce the torque ripple, the current controller based on the perfect tracking control (PTC) is reported. Although it has improved the tracking performance of a current reference compared to the proportional-integral (PI) feedback control and the suppression effect, there is still room for improvement of the current control by reference value oversampling. Thus, we have proposed the pulse merging method that samples a reference value twice more than the conventional method to improve the current control and applied it to the torque ripple suppression at the high-speed range. The proposed method could suppress the torque ripple more than the PTC from the simulation results.