New No-isolated Interleaved Bidirectional soft-switching DC-DC Converter with a Novel Auxiliary ZVT Cell

An interleaved bidirectional soft-switching dc-dc converter with a novel auxiliary zero-voltage-transaction (ZVT) cell is proposed in this paper. Two main switches realizes zero-current-switching (ZCS) turn-on by phase circuits of the converter working in critical conduction mode (C-DCM) in both directions, and realizes ZVT turn-off by proposed auxiliary ZVT cells. Simultaneously, two auxiliary switches achieve ZCT turn-on and small magnetizing-current turn-off. Since the novel auxiliary ZVT cell transferring only the soft-switching energy and not transferring the main power of the converter, the auxiliary ZVT cell can be designed with smaller size and low rated power to achieve the low cost and better efficiency. In addition, the current stress of auxiliary switches can be reduced lower than the load current with no any additional voltage stress. The operating modes and design of the proposed converter have been discussed in this paper, and simulation and experiments are finally conducted to verify their validity.