Optimization of vibro-acoustic by tooth harmonics of IPMSM for EV under multiple operating conditions

Vibro-acoustic is very important considerations in the design of interior permanent magnet synchronous motor (IPMSM) for electric vehicles (EV). In this paper, the problem of large vibro-acoustic of 8-pole 48-slot IPMSM under multiple operating conditions (MOC) is theoretically analyzed to be caused by the first-order tooth harmonics. Vibro-acoustic reduction effects of continuous segmented skewed poles and V-shape segmented skewed poles are compared by finite element analysis (FEA) and optimization of the rotor with 8-segment V-shape skewed poles is given. Finally, the equivalent radiated power level (ERPL) at the largest vibration order caused by tooth harmonics of the optimized motor is decreased by 14.9%; the A-weighted sound pressure level (SPL) at 3500 RPM and 5500 RPM are decreased by 19.7% and 17.6%, respectively.