石墨烯复合绝缘结构的轮毂电机定子散热能力研究

Research on heat dissipation capacity of hub motor stator with graphene composite insulation structure

轮毂电机的效率和稳定性对新能源汽车的品质起着决定性的作用。轮毂电机工作空间紧凑,温升直接决定着轮毂电机的工作效率及寿命,因此研究轮毂电机的散热能力至关重要。以75 kW外转子轮毂电机为例,建立了电机三维物理模型,对该轮毂电机额定工况下的损耗和发热量进行了计算,并计算出轮毂电机各部分的导热系数及换热系数。对比了3种环氧树脂复合材料的导热性能以及电气绝缘性能,最终选定了氧化铝@石墨烯/环氧树脂复合材料作为本文研究电机的绝缘结构材料。对比分析了绝缘结构分别采用普通绝缘材料以及石墨烯复合绝缘材料的定子温度分布,通过对定子铁心关键位置特征点温度分布的提取,揭示了两种材料条件下轮毂电机各特征点沿轴向温度分布规律,研究表明:石墨烯复合材料能够显著增强轮毂电机定子散热能力。

The efficiency and stability of hub motor play a decisive role in the quality of new energy vehicles.The working space of the hub motor is compact,and the temperature rise directly determines the working efficiency and life of the wheel hub motor.In this paper,taking 75 kW outer rotor hub motor as an example,the three-dimensional physical model of the motor is established,the loss and heat generation of the hub motor under rated conditions are calculated,and the thermal conductivity and heat transfer coefficient of each part of the hub motor are calculated.The thermal conductivity and electrical insulation properties of three kinds of epoxy resin composites were compared.Finally,alumina@graphene/epoxy resin composite was selected as the insulation structure material of motor.The temperature distribution of the stator with ordinary insulation material and graphene composite insulation material was compared and analyzed.By extracting the temperature distribution of the characteristic points in the key position of the stator core,the axial temperature distribution of each characteristic point in the two materials was revealed.The research shows that the graphene composite material can significantly enhance the heat dissipation capacity of the hub motor stator.