电动汽车充电机输入阻抗特性分析

Analysis of electric vehicle charger input impedance

针对电动汽车充电机与电网之间的相互作用问题,借鉴DC/DC模块之间相互作用的研究方法,将充电机与电网之间的相互作用问题转化为研究充电机输入阻抗与电网输出阻抗之间的问题.由于电动汽车充电机的输入部分为三相PWM整流器,在d-q坐标系下建立了降阶的三相PWM整流器小信号模型,推导出其开环与闭环输入阻抗表达式.研究充电机输入阻抗随电网电压波动,PWM整流器输出电流、电感寄生电阻和电容寄生电阻,以及电压控制环路和电流控制环路对输入阻抗的影响.

The problem of interaction between electric car charger and the grid is transformed into the research on charging machine input impedance and the grid output impedance by using the research methods of DC-DC modules interaction. The electric car charger input part is three-phase PWM rectifier, so first the small signal model of three-phase PWM rectifier is established in d-q coordinate system, then the reduced order model is established and its open loop and closed loop input impedance expression are deduced. How the charging machine input impedance vary with the change of the grid voltage is discussed. PWM rectifier output current, inductance parasitic resistance, capacitance parasitic resistance, voltage control loop, and current control loop are researched. The paper can provide a basis for the stability analysis of electric vehicle chargers.