A Novel Full-Soft-Switching Full-Bridge Converter With a Snubber Circuit And Couple Inductor

In this paper, a novel full-soft-switching full-bridge converter with a snubber circuit and couple inductor is proposed. The proposed converter can realize soft switching for all of the primary switches and rectifier diodes under light load condition because of the snubber circuit. And the snubber circuit can also achieve soft switching for all of its switches and diodes because of the couple inductor. In addition, the complementary symmetry control for primary-side switches is adopted so there is no shortages of duty cycle loss. The simulation and prototype results are presented to validate the proposed converter.

I. Introduction

High power density and high efficiency switching converters are one of the research hotspots in high frequency switching converters. The effective way to improve the power density of the converter is to increase the switching frequency of the converter. With the increase of the switching frequency, the switching loss of the traditional hard-switching PWM converter increases sharply, which leads to the reduction of the converter efficiency and limits the further improvement of the power density. The soft switching technology of converter can realize zero-voltage-switching (ZVS) or zero-current-switching (ZCS) of switch tube to reduce switching loss and improve the efficiency and power density of the converter, so more and more attention has been paid to it.