基于直流虚拟同步机的直流充电桩反推电流控制

Backstepping Current Control of DC Charging Piles for Electric Vehicles Based on DC Virtual Synchronous Machines

针对电动汽车负载投切容易引起公共电网的电压扰动以及功率变化等问题,比较交流与直流系统中增加惯性的方式,在交流虚拟同步机的基础上,提出一种适用于直流充电桩的直流虚拟同步机控制策略;利用反推法构造反推电流环控制器,以弥补传统比例积分控制动态性能较弱问题,随后将基于直流虚拟同步机的反推电流控制器引入电动汽车直流充电桩,并对电动汽车直流充电桩的应用场景进行模拟。结果表明,所提方法能够很好地稳定直流电压,并能将电压波动限制在10 V以内,验证了所提控制策略的正确性和有效性。

To solve the problems of voltage disturbance and power change of public power grid caused by electric vehicle load switching,comparing the ways of increasing inertia in alternating current(AC)and direct current(DC)systems,a DC virtual synchronous machine control strategy was proposed based on AC virtual synchronous machines.In order to compensate the weak dynamic performance of traditional proportional integral control,backstepping method was used to construct a backstepping current loop controller.The backstepping current control based on DC virtual synchronous machines was then introduced to DC charging piles for electric vehicles,and the application scenario of DC charging piles for electric vehicles was simulated.The results show that the proposed method can stabilize DC voltage well and limit voltage fluctuation to less than 10 V,which verify the correctness and effectiveness of the proposed control strategy.