特种车辆重载电动轮用轮毂电机热特性分析及冷却水道优化

Thermal Performance Analysis and Water Channel Optimization of Hub Motor in the Heavy-Duty Electric Wheel for Special Vehicles

为了准确分析轮毂电机温度场,基于电磁场有限元分析,采用考虑旋转磁化及谐波磁场的方法计算铁耗,并计算了轮毂电机各部件生热率。采用基于有限体积法的流固耦合分析和基于热网络法的磁热耦合分析,分别计算了额定工况下轮毂电机温度场,将轮毂电机温升试验和仿真结果进行了对比。结果表明,基于有限体积法的流固耦合分析得出的绕组稳态温度计算误差为1.8%,基于热网路法的磁热耦合分析计算误差为2.5%,验证了两种温度场分析方法的正确性。对不同结构冷却水道的热阻和压降进行了理论分析,基于Pareto遗传算法对螺旋型水道进行多目标优化,在保证额定工况电机稳态温升基本不变的情况下使水道压降降低了22.9%。

The heavy-duty electric wheel with large bearing loads and output torque for special vehicles consists of a hub motor,a brake,a reducer and a bearing device.The excessive temperatures will affect the driving characteristic,reliability and safety of the hub motor due to its limited installation space and poor heat dissipation condition.In order to accurately analyze the temperature field of the hub motor,based on the finite element method for electromagnetic field analysis,the stator iron loss is calculated by the method considering the effect of the rotating magnetic field and harmonic components.The heat generation rate of each part of the hub motor is calculated as well.The temperature field of the hub motor under rated conditions is obtained by performing the fluid-solid coupling analysis based on the finite volume method and the magnetic-thermal coupling analysis based on the thermal network method.The motor temperature rise test results and the simulation results are compared.For the winding steady-state temperature,the calculation error from the fluid-solid coupling analysis is 1.8%and the error from the magnetic-thermal coupling analysis is 2.5%,which verifies the correctness of the two analysis methods.The thermal resistance and pressure drop of cooling water channels with different structures are theoretically analyzed.By applying the Pareto genetic algorithm,the multi-objective optimization of the spiral water channel is carried out,which reduces the pressure drop in the channel by 22.9%while the steady-state temperature rise of the motor under rated conditions remains basically unchanged.