ZVZCS asymmetrical half-bridges in series hybrid DC-DC converter

A novel zero-voltage and zero-current-switching (ZVZCS) asymmetrical half-bridges in series hybrid DC-DC converter is proposed. Voltage stress of each main switch in this converter is reduced to half of the input voltage, which makes the converter quite suitable for high input voltage applications. The ZCS condition for lagging switches under wide load range is provided by a secondary auxiliary circuit, and an unbalanced-voltage-division flaw which inheres in ZVS half-bridges in series hybrid DC-DC converter is overcome in the proposed converter, consequently the converter is more practical. Furthermore, the ZVZCS converter's efficiency is enhanced owing to its primary circulating current being eliminated basically. The principle and characteristics of the proposed converter is analyzed, and based this a 240 W (24 V/10 A output) experimental prototype is designed and built. The experimental results are presented.