Research on methods of starting-up and stopping magnetic reset for a three-phase single-stage full-bridge PFC converter

Methods of starting-up and stopping magnetic reset of boost inductors were investigated for a three-phase single-stage power factor correction (PFC) converter, which was based on current-fed full-bridge boost topology and operated in discontinuous current mode (DCM). The boost inductors were replaced by the central-tapped inductors with flyback windings, and a novel structure of PFC circuit was proposed which can start up and achieve stopping magnetic reset of boost inductors by itself. The converter operated in flyback mode when starting and stopping, and the charging of output filter capacitor and magnetic reset of boost inductors were realized respectively with the help of flyback windings. The process of starting and stopping magnetic reset of boost inductors of the converter was analyzed, and the constrained conditions of the key parameters were given through comparing with the characteristics of steady state. Experimental results show that it achieves starting-up and stopping magnetic reset for this converter, and prove the validity and feasibility of the proposed methods. © 2010 Chin. Soc. for Elec. Eng.