纯电动汽车驱动电动机系统效率模型的试验

为了在工况变换控制过程中,实现基于电动机系统最佳效率的优化控制,构建了电动机系统效率与转速及转矩之间的关系式.由实车测得的数据,确定了研究工况的范围,在电动机加载试验台上对电动机系统效率特性进行了测试,结果显示被测驱动电动机系统效率η>80%的区域面积占整个测试区域范围的77.1%.基于最小二乘法,对电动机系统效率进行曲面拟合,综合考虑拟合结果的精度及运算工作量,确定采用4次函数构建电动机系统效率模型;利用驱动电动机外特性部分工况点测试结果对模型进行了验证.结果表明:模型计算值与实测值的最大相对误差为3.9%,建立的模型是有效的,该模型能够为在整车控制器中制定基于电动机系统最佳效率的优化控制策略提供依据.

Efficiency model test of electric vehicle driving motor system

To optimize vehicle control process according to optimal efficiency of motor system,the relationship of motor efficiency versus motor speed and torque was established.The experimental research was curried out under the work conditions measured from a real vehicle,and efficiency characteristics of the motor were obtained through a bench test.The results show that the motor system efficiency over 80% can be achieved within the range of 77.1% testing area.Electric motor efficiency data were fitted by Ordinary Least Squares(OLS).A quartic function was selected to describe the efficiency of the motor system based on the accuracy of fitting results and calculation complexity.The simulation was validated by the measured results which were obtained at full load characteristics of electric motor.The maximum relative error of 3.9% indicates that the function or model is reasonable.The proposed model can provide basis for optimizing vehicle control strategy based on the best efficiency of motor system.