A single-stage power factor corrected converter with continuous conduction mode operation and regenerative clamping

A single-stage two-switch forward converter with power factor correction (PFC) and regenerative clamping is proposed. Input current shaping, isolation, fast output regulation and switch turn-off voltage clamping are achieved in a single stage. The input boost inductor can be operated in continuous-conduction-mode, which results in lower conduction losses. The switching loss is reduced thanks to a snubber capacitor. For universal input applications, the voltage across the DC-bus capacitor is kept below 450 V by properly selecting the turns ratio between the additional and primary transformer winding. Therefore, a low cost capacitor can be used. The total harmonies of the converter can meet the EN610003-2 regulation. Experimental results verified the theoretical analysis.