Design and simulation of bidirectional DC-DC converter topology for battery applications

Abstract

Recently, energy storage has become a significant topic for renewable energy based power system applications. Batteries are one of the most popular energy storage devices adopted by renewable energy sources, electrical vehicles and grid connected systems. In this context, the bidirectional DC-DC converter (BDC) enables bidirectional power flow by controlling the charging and discharging stage of the battery in battery applications. Accordingly, the battery current is regulated through the duty cycle of the BDC considering the state of charge of the battery and current direction. In this study, a non-isolated BDC, has a buck and boost principle of operation, is designed, analysed and simulated under various case studies. In the designed system, BDC controls the bidirectional power flow between the battery and DC link. Specifically, in the charging stage of battery operating in buck mode, DC-link supplies the power to the battery and BDC regulates the battery current using proportional-integral (PI) controller. On the other hand, in the discharging stage of the battery operating in boost mode, when DC source is disconnected, the battery supplies the power to DC load and DC-link voltage is controlled by the BDC via PI controller. The simulation results are presented to show the operation and control of the BDC under different scenarios.