The half-wave quasi-resonant ZCS flyback converter as an automatic power factor preregulator: an evaluation

The flyback topology presents several advantages over the popular boost configuration for the design of power factor preregulators. In particular, the transformer provides input-output isolation and the output may be a low voltage DC bus as needed in distributed power supply systems. In this paper, the authors show that a QR-ZCS flyback power converter can provide automatic line current shaping. Experimental results taken from a 150 W prototype validate the theoretical analysis