电动汽车充电系统滑模控制方法研究

Research on Sliding Mode Control Method for Electric Vehicle Charging System

该文将电动汽车充电系统分为整流系统和降压系统。整流系统集充电、驱动与一体,根据磁场抵消原则,使电机在充电过程中保持静止。针对降压系统输出电压动态响应速度慢,稳态精度不高等缺点,提出一种基于改进幂次趋近律的滑模控制方法。改进幂次趋近律使系统在一定时间内到达滑模面。在受到有界外部扰动时,滑模面与其导数收敛到平衡点附近邻域内。定义降压系统输出电压误差和误差变化率作为状态变量,设计二阶滑模控制器,并给出控制器参数选择范围。搭建控制器仿真模块和实验平台,仿真和实验结果表明,整流系统直流侧电压稳态性能较好,基于改进幂次趋近律的降压系统能较好提高系统动态性能,增强稳态精度,减小抖振。

The paper divided electric vehicle charging system into a rectification system and a buck system.The rectification system integrates charging,driving and integration,and kept motor stationary during charging process according to the principle of magnetic field cancellation.Aiming at the shortcomings of slow output dynamic voltage and low steady-state accuracy of buck system,a sliding mode control method based on improved power reaching law was proposed.The improved power reaching law caused the system to reach sliding surface over a certain period of time.When subjected to a bounded external disturbance,the sliding surface and its derivative converged into the neighborhood near the equilibrium point.Define output voltage error and error rate of the buck system as state variables,designed the second-order sliding mode controller,and gave controller parameter selection range.The controller simulation module and experimental platform were built.The simulation and experimental results show that the steady-state performance of rectifier system DC side is better.The buck system based on improved power reaching law can improve dynamic performance of the system and enhance the steady-state accuracy,reduce chattering.