摘要：根据车用水冷型高功率密度永磁同步电机的结构特点建立了三维流体场物理模型。采用三维有限元法对机内空气的流动特性和冷却水道散热性能进行了详细分析，得到了机内空气端部空气和气隙空气的分布规律以及冷却水道的散热系数，并对20 kW车用永磁同步电机进行了稳态温度场计算和实验，测试结果验证了分析方法和结果的有效性，为车用高功率密度永磁同步电机的开发提供了参考依据。

关键词：电动汽车；永磁同步电机；流体场；温度场；流动特性
Abstract: According to the structure characteristics of water cooling high power density of permanent magnet synchronous motor (PMSM), a physical model of 3D fluid field
was established. The air flow characteristics and water channel heat transfer performance was analyzed in details by 3D finite element method (FEM), the distribution law of inner air in end region and air gap region and the heat transfer coefficient of water channel was obtained. Then, based on these results, a steady thermal filed calculation of 20 kW PMSM for electric vehicles (EVs) and a temperature rise experiment was carried out. The analysis results were verified by the temperature test results, and the reference gist for the development of high power density PMSM for EVs was provided. 

Key words: Electric Vehicles；PMSM； Fluid Field； Thermal Field； Fluid Characteristics