High-Frequency Fully-ZVS Isolated Current-Fed Bidirectional DC-DC Converter

In this paper, an isolated high-frequency current-fed DC-DC bidirectional converter with zero voltage switching (ZVS) operating is proposed. The proposed converter can be operated as both step-up and step-down converter. In the proposed converter, there is a main transformer which is used for isolation of low voltage side from the high voltage side. Moreover, the proposed converter has achieved the capabilities of having an isolated structure with lower volume, bidirectional operation, high voltage conversion ratio, zero voltage switching operation of all four switches, simple switching pattern, achieving a simple controlling scheme for the whole range of duty cycle (0<D<1), high-frequency operation, and high-power density. The proposed converter is implemented for an operating frequency of 1MHz and the experimental results verify the theoretical results.