Enhancing Electric Vehicle Charging Stations with High Efficiency Sic- Based Three-Port Dc/Dc Converters

This paper introduces an inventive isolated port of three DC/DC converter that melds a series resonant converter (SRC) and a dual active bridge (DAB) converter, with a specific focus on catering to the charging needs of electric vehicle (EV) stations, including both fast and slow charging capabilities. The port configuration of the proposed converter simplifies the component requirements, leading to cost reductions and a more compact system design when compared to standalone charger systems. The control approach is straight forward, employing phase shift and frequency modulation to concurrently regulate the output power of both fast and slow charging ports. Furthermore, an phase shift angle is determined to minimize transformer current when exclusively operating the DAB adapter for slow charging. To validate the converter's performance, a 5-kW SiC-based simulation with an impressive power density of 2.74 kW/dm³ is tested using a 600 V input voltage, and a 400W SiC-based prototype is assembled and tested with a 48 V input voltage. The converter consistently delivers high-efficiency over a wide variety of output voltages, with rated efficiency reaching 98.2%.