电动汽车电驱动系统高速区快响应控制策略

Study of High Dynamic Response Strategy for Electric Vehicle Drive System in the High-Speed Region

电动汽车电驱动系统要求宽调速范围内转矩响应迅速,同时要有较高的效率。本文首先结合汽车典型循环工况,分析了电动汽车行驶过程中电动机的工作特点,给出了一种基于损耗模型的感应电机效率优化方法,并探讨了其在基频以上的最优磁通选择限制;然后在分析优化运行对感应电机动态响应速度影响的基础上,提出一种适用于基频以上的快速转矩响应控制策略,根据动态过程中电压限制的偏移调整分配电机的励磁和转矩电流给定,突破了基于稳态分析的最大转矩控制策略在分析和解决动态过程转矩输出能力问题时的局限性;并以TMS320LF2407ADSP为控制核心组建了实验系统。仿真和实验结果表明,提出的控制策略可在动态中提供较大的转矩输出,减小了采用效率优化控制对电动汽车高速运行时动态响应速度的影响。

Electric vehicle drive systems request fast torque response speed in wide range of velocity and high efficiency as well. In this paper, the operation characteristics of induction motor in typical drive cycle are analyzed at first, an efficiency optimization strategy based on loss model is given, and the optimization magnetic flux choice restriction above the base frequency is discussed; then by analyzing infection of dynamic response speed caused by efficiency optimization strategy, a fast torque response control strategy suitable above base frequency, which distribute magnetizing current and torque current according to the voltage constraint offset in the dynamic process, is proposed. The strategy breaks through the limitation of maximum torque control strategy, which based on the steady state analysis, when solving fast torque output problem in dynamic process. The experiment system is built with TMS320LF2407A DSP. The simulation and the experimental results indicate that the proposed control strategy can provide fast torque response speed in dynamic process, reduce the infection of electric vehicle＇s dynamic response speed caused by efficiency optimization strategy.