A novel lossless passive snubber for soft-switching boost-type converters

A novel lossless passive snubber is proposed for soft switching the boost-type converters. The proposed snubber does not use any auxiliary switches, but uses two identical snubber capacitors which are charged in parallel at turn off of the main switch and discharged in series at turn on automatically, and the discharged energy is recovered effectively (more than 95% recovery) into the output capacitor. Thus, the snubber provides zero-voltage switching for the converter main switch, reducing both the turn-off losses and the electromagnetic interference (EMI) noise, which improves the converter performance. The experimental results of a 20-kHz 600-W de-de boost converter and a single-phase ac-dc boost rectifier with the new snubber are presented.