A Nonisolated Bidirectional ZVS-PWM Active Clamped DC–DC Converter

Power electronic converter systems for applications such as telecom, automotive, and space can have dc voltage buses that are backed up with batteries or supercapacitors. These batteries or supercapacitors are connected to the buses with bidirectional dc-dc converters that allow them to be discharged or charged, depending on the operating conditions. Bidirectional dc-dc converters may be isolated or nonisolated depending on the application. A new soft-switched bidirectional dc-dc converter will be proposed in this letter. The proposed converter can operate with soft switching, a continuous inductor current, fixed switching frequency, and the switch stresses of a conventional pulsewidth modulation converter regardless of the direction of power flow. These features are due to a very simple auxiliary active clamp circuit that is operational regardless of the direction of power flow. In the letter, the operation of the converter will be discussed and its feasibility will be confirmed with experimental results obtained from a prototype.