Novel Dual Active Bridge Based Multi Port Converter for Interfacing Hybrid Energy Storage Systems in Electric Vehicles

Abstract

Supercapacitors (SC) are required in EVs to supply the large power required during starting and acceleration, which strains the battery and deteriorates its life. To match the Supercapacitor voltage and interface it to the DC link, a DC/DC converter is required in between. A multi-port converter (MPC) based on Dual Active Bridge topology is proposed in this paper, which aims at electric vehicle applications for interfacing battery and supercapacitor to the drive train. Dual active bridge converters provide isolation, bidirectional power capability and also enable soft switching, all of which are highly desirable features for an EV application. In the proposed converter, the battery is operated in current control mode to regulate the battery current and to protect the battery from power surges, whereas the difference power is supplied by the Supercapacitor. The proposed MPC can also be used to charge the battery from any DC input (higher than battery voltage) by regulating the battery current. This eliminates the need for an onboard DC/DC converter. The proposed converter has been validated using simulations and those results are presented.