电动汽车新型永磁同步电机的非均匀气隙建模及性能分析

Modeling and Performance Analysis for Non-Uniform Air Gap in New Type of Permanent Magnet Synchronous Motor of Electric Vehicle

针对电动汽车永磁同步电机输出扭矩大、恒功率调速范围宽的需求,研制了一种新型内置切向径向并联磁路非均匀气隙永磁同步电机。通过建立非均匀气隙转子正弦分布子域模型,并结合能量法和傅里叶分解法,推导了均匀气隙和非均匀气隙时齿槽转矩的解析表达式,获得了转子偏心距对齿槽转矩、弱磁扩速倍数的影响规律。结果表明:对于提出的内置切向径向并联磁路永磁同步电机,当转子偏心距为4mm时,电机峰值齿槽转矩削减了62%,弱磁扩速倍数提高了16.7%。试制的样机通过试验验证了理论分析的正确性。

Aiming at the demand of large output torque and constant-power speed regulation range for permanent magnet synchronous motor for electric vehicles,a new type of permanent magnet synchronous motor with interior tangential-radial parallel non-uniform magnetic flux gap is developed.Establishing the sinusoidal distribution sub-domain model of non-uniform air gap and combining the energy method with Fourier decomposition method,the analytical expressions of the cogging torque in the uniform air gap and non-uniform air gap are derived,and the influences of the rotor eccentricity on the cogging torque and the flux-weakening speed expansion rate are revealed.The results show that for the permanent magnet synchronous motor with interior tangential-radial parallel magnetic flux gap,when the rotor eccentricity gets 4mm,the peak value of cogging torque is reduced by 62% and the flux-weakening speed expansion is increased by 16.7%.The prototype is manufactured,and the correctness of the theoretical analysis is verified by the experiments.