Three-phase Fly-back AC/DC Converter with Novel Resonant Snubber Circuit

The paper presents a new three-phase fly-back single stage AC/DC converter topology with a novel particular ZCS circuit that provides a high power factor, low switching component stress, low cost and low complexity power supply interface to the utility such as mobile telecommunication base station. The circuit topology of the converter is based on the three phase discontinuous current mode (DCM) fly-back converter. By means of a new resonant snubber circuit which involves an assistant switching component, the effective control of the peak current and voltage at the time of the switching-off operations, nearly zero current switch-off and lower switching loss is realized. The simulation and implementation results verify that the proposed converter achieves a near-unity power factor at the input and a high quality DC voltage at the output side of the interface.