Reduction in Circulating Current with Improved Secondary Side Modulation in Isolated Current-Fed Half Bridge AC-DC Converter

Current-fed half bridge converter with bidirectional switches on ac side and a full dc of high frequency transformer is an optimal topology for single stage galvanically isolated ac-dc onboard vehicle charging application. AC are actively commutated to achieve zero current switching (ZCS) using phase shift modulation (SPSM) discontinuous (DCPSM). Furthermore, voltage turn-on (ZVS) achieved switches. Compared SPSM, DCPSM maintains constant peak in the throughout grid cycle mains voltage. However, contributes circulating near crossings also at light load conditions.This paper proposes improved (IDCPSM) increase efficiency across different loading conditions. A dual control variable adopted reduce while maintaining soft both 1.5 kW laboratory prototype has been developed experimentally validate analysis, design improvement performance