Nonisolated Bidirectional Zero-Voltage-Switching DC–DC Converter

A new nonisolated bidirectional zero-voltage-switching (ZVS) dc-dc converter is proposed. The proposed converter can operate with ZVS, fixed switching frequency, and a ripple-free inductor current regardless of the direction of power flow. To provide ZVS of the power switches and a ripple-free inductor current, the proposed converter utilizes a very simple auxiliary circuit that consists of an additional winding to the main inductor and an auxiliary inductor. Due to ZVS operation, the reverse recovery problem of the antiparallel body diode of the power switch does not occur. Moreover, the ripple-free inductor current can reduce the voltage ripple. Theoretical analysis of the proposed bidirectional dc-dc converter and the experimental results obtained on 100-W prototype are discussed.