Isolated ZVS high step-up DC-DC converter with interleaving operation

An isolated zero-voltage-switching (ZVS) high step-up DC-DC converter with interleaving operation is proposed in this paper. The proposed converter consists of two identical DC-DC converters. Their input stages are paralleled and interleaving control scheme is adopted to reduce input current ripple. In order to raise the voltage gain, output stages are connected serially. Due to this structure, the voltage gain can be increased without large turn ratios of isolation transformers. In addition, voltage doubler structure is selected for the output stage and the voltage stresses of output diodes are confined to half of the output voltage without any snubbers. Power switches and output diodes in the proposed converter can operate with soft-switching. Therefore, the switching losses are significantly reduced and high efficiency is achieved. Steady-state analysis, simulation, and experimental results for the proposed converter are presented to validate the feasibility and the performance of the proposed converter.