Medium Voltage Dual Active Bridge Using 3.3 kV SiC MOSFETs for EV Charging Application

Electric vehicle charging technology has come a long way and seen progressive outcomes toward a wide adoption of EVs. To further accelerate the EV evolution, though, the recharging time of electric vehicles will require much improvement. In order to address such a challenge, it is critical to develop a technology that would enable faster, more efficient, and more effective ways of charging an electric vehicle. In order to address such a challenge, it is critical to develop a technology that would enable faster, more efficient, and more effective ways of charging an electric vehicle. The current fast-charging solution involves a heavy and bulky MV-LV transformer, which adds installation complexity for EV charging stations. Therefore, this paper presents an alternative power-delivery solution utilizing a medium-voltage (MV) dual-active-bridge (DAB) converter. The proposed architecture is designed to directly interface the MV grid for high-power, fast-charging capability while eliminating the need for the installation of the MV-LV transformer. The MV DAB converter utilizes 3.3 kV SiC MOSFETs to realize the next 800 V EV charging system. This paper also provides an extended zero-voltage-switching (ZVS) scheme for the MV DAB converter by varying the input (DC-Link) voltage and the switching frequency of the converter. With the system specifications and requirements, a scaled-down 12 kW MV DAB prototype was developed, and its charging operation along with the extended ZVS scheme was simulated and verified by experiments.