Abstract: A capacity configuration scheme and a filter design method for power electronic transformer topology with electric vehicles fast charging interface are presented. First, the electric vehicle fast charging load forecasting based on Monte Carlo method is introduced. Considering the relationship between the EV fast charging and the basic predicted AC load, the capacity of the switchable power module is configured. Then, in order to reduce the apparent power of the inverter module and reduce the PET investment and operation loss, the low voltage side filter is designed with common inductor and its capacitor is considered to compensate the reactive power of load. Finally, the proposed capacity configuration scheme and filter design method are verified by an example analysis and simulation.