Input Impedance Analysis and Optimization for BEV Battery Charger

In the BEV (Battery Electric Vehicles) charging station, each charger is equivalent to the whole system of a subsystem. The interaction among the BEV chargers is likely to deteriorate the stability and dynamical performance of the whole charging system, even making the system unstable. The research on input impedance characteristics of BEV charger is very important in the stability estimation for charging systems. This paper shows that when the BEV charger topology and main circuit parameters have been set, how other parameters such as input voltage, output power, ESR of output filter, crossover frequency and phase margin affect the system performances. Through simulation, with the input voltage, output power, ESR of output filter, crossover frequency and Phase Margin as running parameters, how closed-loop input impedance change is found. Experimental results verify the theoretical analysis is correct.