Optimal design of rotor structure for vibration and noise reduction in electric vehicle generator

In order to reduce the vibration noise of an extended-range electric vehicle (EREV) generator, an optimization method based on changing the rotor structure is proposed in this paper. Firstly, the specific optimization scheme is determined by theoretical and simulation analysis to perform skew pole segmentation of the rotor, while using an eccentric pole arc design to determine the optimal parameters with the target of cogging torque. Then, in order to verify the feasibility of the scheme, the main performance of the generator before and after the optimization is analyzed, including radial electromagnetic force wave, counter-electromotive force (counter EMF), electromagnetic torque, and rotor strength. Finally, a high-precision finite element model of the generator was established, the vibration acceleration, as well as the sound pressure level before and after optimization, were calculated, and a noise test was completed. The results show that the optimized scheme significantly weakened the cogging torque of the generator, while reducing the radial electromagnetic force wave and counter EMF distortion rate to a certain extent, and finally significantly improved the vibration and noise performance of the generator.