新能源汽车(NEV)驱动电机对于转矩密度、功率密度、转矩脉动、振动噪声和高效率区间等参数有着较为严格的性能要求。转子拓扑及其结构尺寸直接影响电机的磁场大小、磁场分布和谐波磁场含量，对于汽车电机性能起着重要影响。针对该类电机多工况多性能参数的特点，利用有限元软件建立主要工况的电磁场计算模型，确定需要优化的转子结构尺寸。根据车用电机的主要性能指标，以转矩脉动、齿槽转矩、气隙反电动势谐波畸变率和输出转矩作为优化目标，根据不同工况性能需求定义目标函数，选择遗传算法作为多目标优化设计算法，再根据优化计算结果进行方案筛选，最终确定电机的最优转子尺寸。该优化设计方法可快速确定车用永磁电机的最优电磁设计方案，丰富了该类电机的高效优化设计途径。

The new energy vehicle (NEV) motor has strict performance requirements for such parameters as torque density, power density, torque ripple, vibration noise and high efficiency section. Rotor topology and its structural parameters directly affect the magnetic flux density, magnetic field distribution and harmonic magnetic field contents, so they play an important role in the performance of NEV motor. For NEV motor, there are different operating conditions and various performance parameters. Finite element software is used to build the electromagnetic field calculation model for the main operating conditions and determine the structural parameters to be optimized. According to the main performance of vehicle motor, the optimization objective is defined with torque ripple, cogging torque, airgap induced voltage total harmonic distortion (THD) and output torque. The objective function is defined according to the performance requirements of different working conditions, and the genetic algorithm is selected as the multiobjective optimization design algorithm. According to the optimized calculation results, the scheme selection is outlined. Finally, the optimal structure and size parameters of the rotor are determined. The optimization design method can quickly determine the optimal electromagnetic design scheme of vehicle permanent magnet motor and enrich the efficient optimization design approaches of this kind of motor.