An Integrated Power Converter Topology for Electric Vehicles With Supercapacitor Energy Management and Soft-Switching

Abstract

Electric vehicles (EVs) require power converters that are efficient, compact, and capable of managing hybrid energy storage systems. Conventional designs use separate DC-DC converters for the supercapacitor and battery, which increases hardware count and losses. This paper proposes an integrated converter topology that combines the supercapacitor interface with the motor-side inverter through a modified auxiliary resonant commutated pole (ARCP) converter. The integration eliminates multiple DC-DC converters while enabling bidirectional energy transfer between the supercapacitor and the drivetrain during acceleration and regenerative braking, and providing soft-switching for the inverter during normal cruise operation. Simulation and experimental validation confirm the stability of DC-link functionality and the efficiency of energy transfer for various driving modes, such as acceleration, constant-speed operation, and regenerative braking. The converter provides soft-switching conditions for the main and auxiliary switches, resulting in a 51% reduction in total losses relative to a conventional hard-switched inverter. The results validate the design’s efficiency and practicality. By simplifying hardware, reducing passive components, and enhancing regenerative energy recovery, the topology provides a compelling option for next-generation EV propulsion systems with the potential to extend driving range, lower cost, and facilitate the wider utilization of sustainable transportation.