Overview of Torque Ripple Minimization Methods for Permanent Magnet Synchronous Motors Based on Harmonic Injection

Permanent magnet synchronous motors (PMSMs) are widely used because of their high power/torque density and high efficiency, particularly in applications with strict requirements for arrangement space or weight, such as in the electric vehicle (EV) and aerospace fields. Recently, the PMSM torque ripple problem has received increasing interest because PMSM drive requirements continuously improve. For applications with complex transmission and a wide speed range, torque ripple can easily cause system resonance, which deteriorates the driving performance. The research status and latest progress in the minimization of PMSM torque ripple based on harmonic injection are discussed. First, the causes of PMSM torque ripple are analyzed. Subsequently, the research status of the PMSM analytical model is introduced, and multiple current harmonic control and optimization methods are described in detail. Finally, future development trends in this field are analyzed.