摘要：Heat generated inside a permanent-magnet (PM) in-wheel motor is usually not well dissipated due to the narrow space inside wheel hub, causing degrading performance and even safety risk. To improve the cooling performance of PM in-wheel motor, we propose a cooling structure in which cooling channels are moved into deepened stator slots. The cooling performance and electromagnetic influence are evaluated through electromagnetic-thermal coupling analysis. The results show that when the output power is kept unchanged, cooling channels at the bottom of deepened stator slots shortens the heat flow path from windings to coolant, lowering the maximum motor temperature from 153.7 to 144.4 °C compared with the scenario of cooling channels in housing. Meanwhile, the motor efficiency is slightly reduced by 0.02% due to the increase of stator teeth height. Moving cooling channels from the bottom to the middle of deepened stator slots increases the contact area between windings and cooling channels, which further lowers the maximum temperature to 129.5 °C. The motor efficiency is further reduced by 0.15% because of the change of winding position. The analysis shows that moving cooling channels into deepened stator slots can significantly lower the motor temperature and yet exerts little influence on the motor efficiency.
关键词：PM in-wheel motor Deepening stator slots Enhancing heat transfer Electromagnetic-thermal coupling analysis
