Lossless passive snubber for half bridge interleaved flyback converter

Discontinues output current of regular flyback converter will cause several problems such as large volume of output capacitor and also high output voltage noise. Interleaved structure can reduce output current ripple and process more power compared with single-phase flyback converter. Normally, reducing the weight and size of a converter is an important goal while designing. An efficient way to reduce the size and weight of a converter and thus increasing power density is increasing switching frequency. However, in this way, switching losses increases. A half bridge interleaved flyback converter with clamp circuit is introduced and improved with a passive lossless snubber circuit. In this structure, the stored energy in parasitic elements is absorbed by passive snubber at turn off instant to provide soft switching condition for all semiconductor elements. The proposed snubber is load independent which is an important characteristic. In addition, a 500 W prototype converter is implemented which can improve the efficiency more than 6%.