An external rotor permanent magnet synchronous generator (ERPMSG) model for Range-Extended Electric Vehicles is developed. The temperature field simulation model of the ERPMSG is established. Experimental test of the winding temperature shows that the simulation model is believable and then it is used to optimize the structural parameters of the cooling water channel. It is found that the pressure loss increases with the number of layers of the cooling water channel increasing and the width of the water channel decreasing. In order to obtain a large turbulent effect and a minimum pressure loss simultaneously, the number of layers of the cooling water channel is set to be 3 and the width of the waterway 8 mm. The corner of the water channel is designed round with an optimum radius of 20 mm. After optimization, the cooling performance of the ERPMSG is obviously improved. Compared with the ERPMSG before optimization, the temperature of the ERPMSG with optimum structure parameters of the cooling water channel is lower. The maximum temperatures of the winding, the stator core and the rotor of the ERPMSG with optimum structure parameters of the cooling water channel decrease 8.19 °C, 5 °C and 7.42 °C respectively. Temperature distribution is more uniform in the permanent magnet of the ERPMSM with waterway structure optimization.

开发了用于增程电动车的外转子永磁同步发电机（ERPMSG）模型。建立了ERPSMSG的温度场模拟模型。绕组温度的实验测试表明，仿真模型是可信的，可用于优化冷却水通道的结构参数。发现随着冷却水通道的层数增加和水通道的宽度减小，压力损失增加。为了同时获得大的湍流效果和最小的压力损失，将冷却水通道的层数设置为3，将水路的宽度设置为8 mm。水道的拐角设计成圆形，最佳半径为20毫米。经过优化后，ERPMSG的冷却性能明显提高。与优化前的ERPMSG相比，具有最佳冷却水通道结构参数的ERPMSG的温度更低。带有冷却水通道最佳结构参数的ERPMSG的绕组，定子铁心和转子的最高温度分别降低了8.19°C，5°C和7.42°C。通过优化水路结构，ERPMSM永磁体中的温度分布更加均匀。分别为5°C和7.42°C。通过优化水路结构，ERPMSM永磁体中的温度分布更加均匀。分别为5°C和7.42°C。通过优化水路结构，ERPMSM永磁体中的温度分布更加均匀。