Passive resonant snubber-assisted two-switch flyback converter with auxiliary pulse transformer for energy recovery

In this paper, a two-switch high frequency flyback transformer linked zero voltage soft switching PWM DC-DC power converter implemented in distributed power conditioning supplies is proposed. This DC-DC power converter circuit is mainly composed of two active power switches and a flyback high frequency transformer. In addition to this, two passive lossless resonant snubbers with pulse current regeneration loops for energy recovery, consisting of a three winding auxiliary high frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this DC-DC power converter has some advantages such as low cost circuit configuration, simple control scheme and high efficiency. Its operating principle is described and discussed here. To determine circuit parameters, some practical design considerations are discussed. Moreover, the effectiveness of the proposed soft switching PWM DC-DC power converter is evaluated and compared with its equivalent hard switching PWM power DC-DC converter from an experimental point of view.