Comparison of electromagnetic torque ripple in square wave and sine wave permanent magnet motor drives

Abstract

This paper presents the comparison of torque ripple in a permanent magnet motor drive with trapezoidal and sine wave back EMFs, excited by quasi square and sinusoidal currents. The analysis is done for an application where the speed range requirement spans from 10 RPM to 500 RPM. The simulation results show that the permanent magnet motor drive with sinusoidal back EMF excited by a sinusoidal current, which is in phase with the back EMF, gives minimum torque ripple and maximum efficiency.