Characteristics of PM Synchronous Motor Drives with a trapezoidal EMF

Abstract

A permanent magnet synchronous motor (PMSM) with non-sinusoidal electromotive force (EMF) generates torque ripple even if the sinusoidal PWM inverter drives the PMSM. A new modified trapezoidal modulating signal for PWM inverter suitable for PMSM drive with non-sinusoidal EMF is proposed in this paper. A new modulating signal for the PMSM drive is determined by the condition of reducing torque ripple of the motor with various trapezoidal EMF. When the PWM inverter using modified trapezoidal modulating signal drives the PMSM having a non-sinusoidal EMF, the torque ripple of the motor can be reduced, the DC link voltage utilization is improved and reduction of switching loss can be obtained.