The Study of Cooling Enhancement in Axial Flux Permanent Magnet Motors for Electric Vehicles

In this article, the thermal properties of axial flux permanent magnet motors are investigated. A modified cooling structure is designed to enhance the cooling performance for end windings compared with the conventional cooling structure. The heat flow path in the end thermal conduction region is studied based on the lumped-parameter thermal network model. The influence of the thermal conductivity of potting material and the thickness of stator yoke on cooling performance is discussed. The computational fluid dynamics thermal analysis is also employed to give verification and to get the temperature of hot spot. In the end, a prototype motor with the modified cooling structure is tested.