Research on Electromagnetic Noise Optimization of Permanent Magnet Synchronous Motor Based on Harmonic Injection

Taking the permanent magnet synchronous motor used in electric vehicle drives as the research object, this paper analyzes the influence of harmonic components on the vibro-acoustic response. A speed/torque harmonic injection method has been constructed to suppress the electromagnetic noise. Based on a certain NVH test and its related results, the harmonic influence on the electromagnetic acoustic noise has been firstly analyzed. Secondly, a high-speed mathematical motor model and a radial electromagnetic force model, considering the magnetic interaction between the stator winding harmonics and the permanent magnet, are fully established. The correlation between harmonic components and radial electromagnetic force has been also analyzed considering the speed/torque factors. Then, a harmonic injection method based on SVPWM is further proposed, in which the control model for the 5th and 7th harmonic currents are also implemented. Finally, with the experimental verification under different speed and torque conditions, the results show that the harmonic injection method can effectively suppress electromagnetic noise. This work can provide the theoretical and practical basis for optimizing the electromagnetic noise in the drive motor system.