A new soft switching PWM DC-DC converter with auxiliary circuit and centre-tapped transformer rectifier

Abstract

This paper proposes a novel soft switching isolated dc to dc converter. The proposed topology consists of a basic half-bridge dc-dc converter and an auxiliary circuit. The auxiliary circuit consists of two active switches and one capacitor. The main power switches operate with ZVZCS while the power switches of auxiliary switches operate under ZCS conditions. The output voltage of the proposed converter is varied by PWM control. The main features of the proposed converter are simple circuit, less component count and soft-switching operation over the wide control range. The operating principle, theoretical analysis and design example of the proposed converter are provided. The experimental results obtained from a laboratory scale down prototype are presented and discussed in this paper. The presented results confirm the soft-switching operation of the converter.