电动汽车驱动电机结构参数优化设计

在研究电动汽车驱动电机参数匹配过程中, 提出了一种驱动电机结构参数优化设计方法。在已知电机基本参数基础上, 分析了电机轴向长度、转子外径、绕组匝数、线径、极弧因数、永磁体厚度等参数对电机效率的影响。建立了电机主要本体结构参数与效率特性的映射关系, 提出了电机本体结构参数的初始设计和优化设计流程。利用优化设计得到的电机效率特性, 通过正向仿真整车模型, 在4种典型工况下进行了整车的经济性仿真验证。仿真结果表明: 在外特性方面, 优化电机相比初始电机的转矩脉动明显降低, 其中恒转矩区域降低为14%, 恒功率区域不超过40%, 且最高效率提升为94%;在整车经济性方面, 优化电机在NEDC、UDDS、JC08、1015工况使整车单位里程能耗分别降低7.1%、6.7%、4.1%、2.9%, 平均为5.2%。可见, 优化设计方法在满足整车动力性需求的前提下, 改善了电机在高效率区间的工作点分布, 显著提高了电机在高转速、低转矩范围的平均效率; 设计方法能更好地提升电机的驱动效率, 为从整车性能要求出发的电动汽车驱动电机本体结构参数优化设计提供理论指导。

Optimal design of driving motor structural parameters for electric vehicle

In the process of parameters matching study of driving motor for electric vehicle, an optimal design method for structural parameters of driving motor was proposed.Based on the basic given motor parameters, the influences of axial length, rotor outer diameter, winding turns, wire diameter, pole arc factor, and permanent magnet thickness on motor efficiency were analyzed.The mapping relationships between the main ontology structural parameters and the efficiency characteristic of the motor were established.The procedures of the preliminary design and the optimal design for the motor ontology structural parameters were proposed.Based on the optimized motor efficiency characteristic, the economic performance of whole vehicle was simulated and verified by using the forward-facing simulation vehicle model under 4typical working conditions.Simulation result shows that in the aspect of output characteristic, compared with the initial motor, the torque ripple of optimized motor reduces obviously, the value in constant torque area reduces to 14%, the value in constant power area reduces to no more than40%, and the top efficiency increases to 94%.In the aspect of whole vehicle economy performance, the energy consumptions per kilometer of optimized motor for whole vehicle reduceby about 7.1%, 6.7%, 4.1%, and 2.9% under NEDC、UDDS、JC08、1015working conditions, and the average value is 5.2%.Under the premise of meeting the driving requirements, the operating point distribution in higher efficiency range is improved, and the average efficiency in the area with higher rotational speed and lower torque rises significantly by using the proposed optimal design method.The design method can better improve the driving efficiency of motor, and can supply the theoretical supervision for the optimal design of driving motor ontology structural parameters according to the requirement of vehicle performance.