Torque Ripple Minimization of Permanent Magnet Synchronous Motor with Non-Sinusoidal Flux Distribution Using Predictive Control

Due to non-sinusoidal flux distribution in air gap, Permanent Magnet Synchronous Motors (PMSMs) generate torque ripple which results in speed oscillation and acoustic noise. This paper develops a new method based on predictive control to reduce torque ripple. To obtain desired current in next sample as the input of predictive control, harmonic contents of back electromotive force (EMF) should be obtained. At first, a Sliding Mode Observer (SMO) is used to track back EMF waveform accurately and then Recursive Least Square (RLS) estimator determines harmonic magnitudes. The validity of proposed method is verified by simulation results.