Single-Phase Single-Stage Isolated ZCS Current-Fed Full-Bridge Converter for High-Power AC/DC Applications

In this paper, a single-phase single-stage isolated zero current switched (ZCS) current-fed full-bridge ac/dc converter is proposed for IGBT-based high-power power factor correction (PFC) applications. By adding an additional commutation path and few resonant components, ZCS operation is realized for all IGBTs. The conduction loss is also lowered by the additional path. Furthermore, the control strategy for the proposed converter is compatible with that developed for traditional PFC converter. In this paper, the topology derivation and circuit operational analysis are given. The control strategy is introduced. A 3-kw prototype is developed and tested to verify the circuit functionality. Finally, the efficiency performance is investigated and comparison is made to show the advantages of the topology.