Input-series-output-parallel phase-shift full-bridge derived DC-DC converters with auxiliary LC networks to achieve wide zero-voltage switching range

This letter proposes an input-series-output-parallel derived dc-dc converter composed of two phase-shift full-bridge (PSFB) dc-dc converters and two auxiliary LC networks. Each LC network is connected between the leading-leg midpoint of a module and the lagging-leg midpoint of the other one. For conventional PSFB converters, the lagging-leg switches may lose zero-voltage switching (ZVS) conditions at light loads. In the proposed converter, ZVS for lagging-leg switches can be achieved with the aid of the LC networks even at light loads. The efficiency of the converter at the light load is improved. Therefore, the proposed converter is suitable for the wide load range. The feature of the converter is analyzed. The performance of the proposed converter is verified by a 900 W experimental prototype.