Performance Evaluation of 10kV SiC-based Extreme Fast Charger for Electric Vehicles with Direct MV AC Grid Interconnection

Abstract

This paper evaluates the performance of a 10kV SiC MOSFET based direct Medium Voltage (MV) connected Extreme Fast Charger (XFC) for Electric Vehicle (EV) charging applications. Two-stage converter topology is considered, where the Active Front End (AFE) is directly connected to the 4.16kV MV grid. The MVDC output of the AFE is processed by the isolated DC-DC converter to achieve the output voltage that is compatible with the EV battery. Thanks to the reconfiguration capability, the proposed XFC can charge both 400V and 800V EVs without any significant performance degradation. The data collected through experimental characterization of the 10kV SiC MOSFETs is used for simulating the complete converter of MV-XFC and performing loss analysis through MV SiC modeling in PLECs software. Analytical transformer losses and multiobjective design optimization are obtained using MATLAB. Based on the outcome of the multiobjective design optimization, the converter design parameters are selected and the trade-off between the loss and volume of the proposed design has been evaluated.