A Versatile Two-Port Extreme Fast Charger with Wide EV Range Application

Abstract:
This research proposes a novel two-port Extreme Fast Charger (XFC) system capable of charging vehicles of different power and voltage rating simultaneously and independently with smaller passives requirements. Currently available single-port or multi-converter-based architectures are effective but research suggests there are concerns over complexity, power management, and trade offs. The proposed system integrates a voltage balancer stage with a three-leg Voltage Source Converter (VSC) interfaced through a line-frequency transformer. It enables simultaneous and independent charging across multiple output ports at different voltage and power levels ranging from large buses to smaller two/three-wheelers. Through coordinated control of the VSC and voltage balancer, the system supports precise constant current–constant voltage (CC–CV) charging tailored to modern EV battery profiles. This single-stage architecture significantly reduces the number of power switches and the size of passive components, enhancing power density and efficiency. Furthermore, the design supports bidirectional power flow, facilitating integration of energy storage, and vehicle-to-grid (V2G) or vehicle-to-vehicle (V2V) functionalities. These features enable grid-supportive operations such as peak shaving and backup power, making the solution highly suitable for urban, highway, and other scenarios.