Novel zero-voltage transition semi bridgeless boost PFC converter with soft switching auxiliary switch

By using an active snubber, a novel implementation of the zero-voltage transition (ZVT) semi bridgeless boost power factor correction (PFC) converter is proposed. The active snubber reduces the reverse-recovery-related losses of the boost diodes and also provides zero-voltage switching (ZVS) for the main switches in the proposed converter. Furthermore, the auxiliary switch is operated at soft switching, the rest of the diodes are also realized to turn on and turn off naturally. Operating modes and optimal control strategy of the proposed converter are discussed in detail, and design of the proposed active snubber is given. On the basis of it, a prototype of 100 kHz, 600W, universal ac-line proposed circuit has been built to verify the proposed scheme. The efficiency curves show that the circuit improves efficiency significantly in the wide input voltage range and full power output.