An Overview of the Role of Solid State Transformer in Extreme Fast Charging of Electric Vehicles

The traditional extreme fast charging (XFC) system of electric vehicle (EV) typically interfaces a centralized front-end converter (FEC) with the medium voltage grid using line frequency transformer (LFT). However, LFT has high volume, weight and power losses, as such cannot be used where space and environmental friendliness are of great concern. This paper presents a solid state transformer (SST) based XFC system with the aim of outlining the role of the SST in providing a compact system with reduced space and volume, free from greenhouse emission and providing other ancillary services such as voltage regulation, reactive power compensation and smooth integration of renewable energy resources (RESs).