A Full-Bridge DC-DC Converter With Zero Voltage Switching Over the Entire Conversion Range

Abstract—A new topology of full-bridge dc–dc converter is pro-posed featuring zero-voltage-switching (ZVS) of active switches over the entire conversion range. In contrast to conventional tech-niques, the stored energy in the auxiliary inductor of the proposed converter is minimal under full-load condition and it progres-sively increases as the load current decreases. Therefore, the ZVS operation over the entire conversion range is achieved without significantly increasing full-load conduction loss making the converter particularly suitable in applications where the output is required to be adjustable over a wide range and load resistance is fixed (e.g., an electromagnet power supply). The principle of operation is described and the considerations in the design of converter are discussed. Performance of the proposed converter is verified with experimental results on a 500-W, 100-kHz prototype. Index Terms—DC–DC power conversion, soft-switching, zero-voltage-switching (ZVS)