An Ac-Dc Single-Stage PWM Full-Bridge Converter with a Magnetic Switch

A new ac-dc single stage voltage-fed PWM full-bridge converter is proposed in the paper. The converter can simultaneously perform input power factor correction and dc-dc conversion using conventional phase-shift PWM and can maintain a primary side dc bus voltage of less than 450 V even at a high input line voltage of 265 V. The proposed converter has these features due to the novel implementation and design of a "magnetic switch", which is an auxiliary transformer winding placed in series with the input inductor. In the paper, the general operation of the proposed converter is explained and its operation during a switching cycle is examined in detail. The converter\´s steady-state characteristics are discussed and guidelines for the design of the converter are given. Experimental results, obtained from a prototype, that confirm the feasibility of the converter are presented in the paper