A Novel ZVS PWM FB DC/DC Converter Using Auxiliary Resonant Net

Abstract

In conventional converter phase-shifted zero-voltage-switching DC/DC converter, lagging leg losses ZVS capability at light load conditions, and output rectifier diodes operate with hard switching. A novel soft-switching bi-directional converter employing auxiliary resonant net is proposed to solve these problems. The proposed converter can not only achieve soft switching but also eliminate the circulating current by adding an active clamp circuit in the secondary side and using saturable inductor in the primary side. In result, soft-switching operation range is extended. And all switches satisfy ZVS conditions. Synchronous rectifier technique is adopted in the converter, so the conduction loss is eliminated. In this paper TMS320F240 DSP is used as control chip, and the digital control system of the converter is designed. The experimental results show the feasibility of the proposed converter.