Optimum design of an EV/PHEV charging station with DC bus and storage system

In this paper the optimum design of a fast-charging station for PHEVs and EVs is proposed to minimize the strain on the power grid while supplying the vehicles with the required power. By studying the power demand of the charging station, a conclusion is reached that the size of the grid tie can be reduced substantially by sizing the grid tie for the average rather than the peak power demand. Therefore the charging station architecture with a single AC/DC conversion and a DC distribution to DC/DC charging units is proposed. An energy storage system is connected to the DC bus to supply power when the demand exceeds the average that can be provided from the grid. Various topologies for both the AC/DC and DC/DC conversion are studied to find the optimum design for this application.