Design of a novel 50 kW fast charger for electric vehicles

A novel 50 kW fast charger was proposed for electric vehicles. The proposed fast charger is divided into two main sections: an AC-DC converter performing a PFC function and a DC-DC converter performing a charging function. A transformer including leakage inductances was used in the AC-DC converter in order to obtain isolation and inductance. A series-connection topology was used in the DC-DC converter between the DC-bus and outlet. This topology enables high power conversion efficiency up to 95% for the DC-DC converter. In order to reduce the impact of the 50 kW charging on the AC grid, the proposed fast charger system includes a buffering battery unit between the two main power conversion units. This leads to reductions in the power installation costs of power companies and to improvements in the power quality on the AC grid. The performances of the proposed fast charger system were verified through simulations and experimental results.