A novel passive lossless snubber for current-fed half-bridge isolated dc/dc converter

In this paper, a novel passive lossless snubber is proposed for current-fed half-bridge isolated dc/dc converter. The snubber is composed of two small inductors, three diodes and two capacitors. Compare with traditional hard-switched current-fed half-bridge isolated dc/dc converter, ZVS turned-off for the switches are realized in the proposed converter and the voltage spike of turned-off switch, which caused by the leakage of transformer is alleviated. The operation principles, performance analysis and simulation results with OrCAD/Pspice of the topology are described in detail. A 1000W, 30V-input and ±380V-output prototype has been developed and experimental results validate the analysis and design and the highest efficiency of converter is 92.3%.