High-efficiency bidirectional soft switching DC-DC converter

In order to reduce size of bidirectional DC-DC converter, conventional topologies using hard switching method operate with high frequency. As switching frequency is getting higher, switching loss is increased. Conventionally an auxiliary circuit is implemented by using soft switching method in order to overcome this drawback,. The switch of the auxiliary circuit, however, is operated as hard switching. In this paper, high efficient bi-direction DC-DC converter is proposed. The suggested auxiliary circuit consists of one resonant inductor and two capacitors. Loss reduction is induced from both switches since the switches operate under ZVS turn-on and off condition. Main characteristic of the proposed topology is not only operated with soft switching method but has simple structure. The efficiency of proposed bidirectional soft switching DC-DC converter is verified by experimental results.