Modeling and analysis of nonsinusoidal back electromotive force effect on electromagnetic noise in permanent magnet synchronous motors

This paper presents the modeling and analysis of electromagnetic vibration and noise in permanent magnet synchronous motor (PMSM) under the influence of nonsinusoidal back electromotive force (back-EMF). First, the actual back-EMF of the prototype and the current distortion induced by it are experimentally analyzed. Then, a control model based on the data-driven reduced-order model (ROM) of the prototype is utilized to decouple the effects from nonsinusoidal back-EMF and other non-ideal factors. By combining with a multi-physics model, the electromagnetic vibration and noise of the motor with/without nonsinusoidal back-EMF are calculated and compared. Finally, the variation of the noise and vibration peaks is explained by combining the motor’s modal characteristics and the amplitude changes of the dominant electromagnetic force. It is found that the current distortion caused by nonsinusoidal back-EMF will change the original force amplitude, thereby affecting the vibroacoustic performance of the motor. Compared with existing studies that mainly focus on the torque ripple caused by nonsinusoidal back-EMF while neglecting its impact on vibration and noise, this paper analyzes its influence independently using the prototype’s multi-physics model and ROM-based control model, thereby providing a reference for the analysis and optimization of acoustic performance in PMSMs.