Electromagnetic Vibration Reduction of Surface-Mounted Permanent Magnet Synchronous Motors Based on Eccentric Magnetic Poles

As an important indicator to evaluate the performance of electric vehicles, the electromagnetic vibration of the motor is excited by the electromagnetic force waves acting on the stator core. Considering the influence of complex stator slot structure and inevitable saturation at teeth, the electromagnetic force waves of surface-mounted permanent magnet synchronous motor with eccentric magnetic poles are calculated quickly and accurately by combining the magnetomotive force-permeance method and the improved subdomain method, the amplitudes, orders, and frequencies of electromagnetic force waves are calculated and summarized. Considering the anisotropy of the stator material and the influence of the enclosure and windings, the natural frequencies of the entire stator are analyzed, and the vibration accelerations are calculated by the multiphysics model including electromagnetic, structural, and vibration models. Furthermore, the components of electromagnetic force waves that have a great impact on electromagnetic vibration are summarized, and the optimal parameters of eccentric magnetic poles that can effectively weaken the electromagnetic vibration are obtained by combining the particle swarm optimization algorithm and the subdomain method. For the 6-pole 36-slot motor, the maximum vibration accelerations of the motor are reduced by 45.14% at no load and 42.74% at rated load by optimizing the parameters of eccentric magnetic poles.