Design And Analysis For Zvs Forward-Flyback Dc-Dc Converter

This paper presents a ZVS forward-flyback DC-DC converter for photovoltaic applications. The converter operates at boundary mode or discontinuous mode to achieve ZVS. Variable frequency with constant off time is used for reducing core losses of the transformer, achieving high efficiency. Meanwhile, power distribution between forward and flyback is discussed as well. Finally, a 200W prototype (22Vdc-50Vdc input, 230Vdc output) is built to evaluate the performance. © 2011 IEEE