微型电动车轮毂电机的磁热耦合分析

Magneto-thermal Coupling Analysis on the In-wheel Motors of Micro Electric Vehicles

针对温度变化对微型电动车轮毂电机工作性能和使用寿命的影响,提出了一种磁热耦合分析方法,并对轮毂电机进行了磁场和热场分析。采用Ansoft Maxwell软件建立了轮毂电机的有限元仿真模型,并通过仿真获得了其内部复杂磁通密度云图和磁力线分布图。建立了温度场的数学模型,计算了绕组损耗、定转子铁损和永磁体的涡流损耗,并以此耦合到温度场作为热源。采用Ansys Workbench软件,计算了轮毂电机稳态温度场和各部件的温度分布以及起动过程中定子铁芯与转子铁芯瞬态温度曲线。仿真结果与试验实测温度值基本一致,表明采用磁热耦合方法分析轮毂电机的热源分布与温度分布准确可行,可为今后的轮毂电机优化设计提供基础。

Aiming at the effects of temperature change on the performance and service life of the in-wheel motors in micro electric vehicles, a magneto-thermal coupling analysis method is proposed with the magnetic and thermal fields of in-wheel motor analyzed. A finite element model for in-wheel motor is built with software Ansoft Maxwell, and its internal magnetic flux density nephogram and magnetic line distribution chart are obtained by simu- lation. Then a mathematical model for temperature field is established, and the winding losses, stator and rotor iron losses and permanent magnet eddy current losses are calculated, which are coupled to temperature field as heat sources. Finally Ansys Workbench software is used to calculate the steady-state temperature field and components temperature distribution of in-wheel motor, as well as the transient temperature curve of stator and rotor cores in starting process. The simulation results well agree with tested temperatures, indicating that the analyses on the heat sources and temperature distributions with the magneto-thermal coupling method are accurate and feasible, providing a basis for subsequent optimal design of in-wheel motors.