A Novel ZVS Non-isolated Bidirectional DC-DC Converter for Energy Storage Systems

This paper proposed a new soft-switched non isolated bidirectional converter for energy storage systems. The hard-switched non-isolated bidirectional converter is improved with additional soft-switch cell incorporated with auxiliary active switches, diodes and passive elements. The main operating characteristics of this topology are to transfer the power flow in both directions from low voltage to high voltage and vice versa. While converter operating in boost and buck mode using with unique soft-switch cell, the soft-turn-on feature was achieved without increasing additional losses. The main advantages of this topology are the reduced turn-on losses and improved efficiency. This paper mainly describes the operating principles, design analysis and the theoretical analysis verified by simulation. The simulations were performed on 100/350V/1kW converter system operated at 50 kHz switching frequency.