Phase-shifted full-bridge DC-DC converter with high efficiency and reduced output filter using center-tapped clamp circuit

Abstract

In this paper, a phase-shifted full-bridge converter employing a new center-tapped clamp circuit is proposed to achieve high efficiency and reduced output filter in electric- vehicle battery charger applications. By using a simple center- tapped clamp circuit, which consists of two diodes and a capacitor, many limitations in conventional PSFB converters such as circulating current during the freewheeling interval, severe voltage overshoots across the full-bridge rectifier (FBR) on the secondary side, significant reverse-recovery current in the FBR, and the demand of a large output inductor are all solved. With these advantages, high efficiency can be achieved with saving the cost. In order to confirm the effectiveness of the proposed converter, a 3.3-kW prototype was tested.