A Soft Switching PFC Converter Operating Discrete Conduction Mode with Reduced Losses of the Auxiliary Circuit

In this paper, a new family of zero-current-transition (ZCT) power factor correction (PFC) converters is introduced. The proposed converter operates in discrete conduction mode (DCM) and provides soft switching for the main switch and the auxiliary switch with a small inductor and capacitor even in high power / high voltage application. The auxiliary circuit of proposed converter operates for an enough short time compared with the switching period. Furthermore, the auxiliary circuit maintains an almost constant operation time during a power line cycle. As a result, the proposed converter can reduce the losses of the auxiliary circuit. In this study, a steady-state analysis of the proposed converter is described, and features of this converter are compared to ones of zero-voltage-transition (ZVT) converter in theory. These theoretical analyses are verified by a prototype converter.