应用qZSI的车用IPMSM驱动系统能效优化控制

Efficiency Optimization Control of IPMSM Driving System for Electric Vehicles Using Quasi-Z Source Inverter

针对电动汽车动力电池电压水平较低且驱动系统效率低下的问题,利用准Z源逆变器改善电动汽车用内置式永磁同步电动机驱动系统动力性能,并对系统稳态采用混合效率优化控制。分析准Z源逆变器工作特性,提出一种直流母线电压控制策略,确定准Z源电容电压表达式。系统稳态时采用效率优化控制,推导出电动机损耗表达式,求出气隙电流的励磁分量与转矩分量之间的最优比率,得到直轴电流次优值,再以该值为初始值采用改进型黄金分割法进行二次寻优,该算法寻优速度快且鲁棒性强。同时加入动态定子电流分配,提高电动机动态响应速度。仿真和实验结果表明,所提控制策略能明显提高电动机高速区动力性能和动态响应速度,同时稳态效率提升约4%。

In view of the low voltage level of electric vehicle power battery and low efficiency of driving system, the quasi-Z source inverter is used to improve dynamic performance of the interior permanent magnet synchronous motor driving system for electric vehicles, and hybrid efficiency optimization control is adopted for system steady state. The operating characteristics of quasi-Z source inverter are analyzed, a control strategy of DC bus voltage is proposed and quasi-Z source capacitance voltage expression is determined. Efficiency optimization control is used in steady state, motor loss expression is deduced, and the optimized ratio between excitation component and torque component of air gap current is calculated to get the direct axis current sub optimal value. Then with this value as initial value, an improved golden section algorithm which is fast and robust is used to find the best system operating point. The dynamic stator current distribution is also added to improve the dynamic response speed of the motor. Simulation and experimental results show that, the proposed control strategy can significantly improve the dynamic performance in high speed area and response speed of driving motor, also the steady-state efficiency of system is improved about 4%.