一种基于有界不确定性和扰动估计器的大功率充电桩控制策略

A Control Strategy for High-Power Charging Piles Based on Bounded Uncertainty and Disturbance Estimator

大功率充电桩接入电网是实现多电压等级电动汽车充放电的关键设备,但因电动汽车的即插即用需求和充电功率冲击特性,大功率充电桩接入将对电网运行稳定性带来挑战。提出基于不确定性和扰动估计器(uncertainty and disturbance estimator, UDE)的大功率充电桩控制策略。首先,在大功率充电桩双主动全桥换流器(dualactivebridge,DAB)模块采用虚拟直流电机控制策略,实现对直流电压的基本控制。然后,考虑电动汽车投切对电网稳定运行的影响,基于LC滤波器建立UDE补偿控制环节,对滤波单元动态误差进行反馈,将其输出量作为补偿分量,实现对直流母线电压的补偿控制,从而有效提升直流电压稳定性。最后,基于PSCAD/EMTDC搭建充电桩系统仿真模型,其仿真结果验证了所提控制策略的可行性。

The high-power charging piles integrated into power grid are the key devices for the charging and discharging operation of electric vehicles across multiple voltage levels.However,due to the plug-and-play requirements and impulse charging power characteristics of electric vehicles,the integration of high-power charging piles will bring challenges for the stability of the grid operation.In this paper,a control strategy for high-power charging piles based on uncertainty and disturbance estimator(UDE)was proposed.First,in the dual active bridge converter(DAB)module of the high-power charging pile,the virtual direct current machinery(VDM)control strategy is adopted to realize the basic control of the DC voltage.Then,considering the impact of electric vehicle switching on the stable operation of the power grid,the UDE compensation control link is established based on the LC filter.The dynamic error of the filter unit is fed back with its output taken as the compensation component to achieve the compensation control of the DC bus voltage.In this way the stability of DC voltage can be effectively improved.Finally,by virtue of PSCAD/EMTDC software,a system simulation model with high-power charging pile is built.From the simulation analysis results the feasibility of the proposed control strategy has been verified.