Soft Switching Forward-Flyback DC-DC Converter

This paper presents a zero-voltage switching (ZVS) forward-flyback DC-DC converter, which is able to process and deliver power efficiently over a wide input voltage variation. The converter operates at boundary mode between current continuous and discontinuous mode to achieve ZVS. Variable frequency with fixed off time is used for reducing core losses of the transformer, achieving high efficiency. Meanwhile, power distribution between forward and flyback is analyzed as well. Finally, experiment results provided from a 200W prototype (25Vdc-50Vdc input, 230Vdc output) that validates the feasibility and good performance of the proposed converter.

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