考虑铁损的电动汽车用感应电机矢量控制及其能量优化策略

电动汽车用感应电机励磁电感一般较小,高速时铁损大,采用经典矢量控制策略存在轻载低效和由忽略铁损引起的控制不精确等问题.首先根据同步旋转坐标系下考虑铁损的感应电机动态数学模型,分析了铁损对按转子磁场定向矢量控制的影响,给出了动态和稳态两种补偿方案.然后从调节磁通水平的角度,提出了一种基于损耗模型的感应电机能量优化控制策略,并讨论了铁损等效电阻变化对优化控制的影响.仿真和实验结果表明,给出的补偿控制策略克服了经典矢量控制磁场定向及转矩控制不准确的缺陷;提出的的能量优化控制策略不但节能效果明显,而且具有寻优速度快、转矩和转速波动小等优点,为高性能要求的电动汽车电驱动系统高效运行提供了有效途径.

Vector control of induction motor for electric vehicles considering iron losses and its energy optimization strategy

Electric vehicle induction motors(IM)are usually characterized by their low magnetizing inductance, which causes a significant amount of iron losses especially in high-speed operation. Classical vector control is notorious by its low efficiency under light load and inaccurate control by neglecting iron losses. Firstly, a structure diagram of the IM is proposed in a synchronously rotating frame of reference based on its dynamic mathematical model including iron losses. The effects of iron losses on performance of rotor flux oriented controlled IM are then discussed, and the compensation strategies are also given under both steady-state and transient operations. Moreover, the losses of IM in operation are discussed and an energy optimization control strategy of IM driving system based on loss model is proposed, the effects of iron equivalent resistance variation on energy optimization are analyzed as well. Finally, experimental and simulation results show that the compensation strategy provides good performance on flux and torque control, and the energy optimization strategy improves the motor efficiency remarkably and has advantages of high optimization speed, small torque and speed fluctuation, which provide a sound solution for a good performance and high efficiency IM drive system for electric vehicles.