Wide-Range ZVS Phase-Shifted Full-Bridge Converter With Low Circulation Loss

The conventional PSFB converter has received considerable attentions for medium-or high-power applications, which is because it features high conversion efficiency and high power density. However, the hold-up-time requirement limits its operating duty ratio in nominal state and it increases the conduction loss caused by circulating current. Therefore, by introducing an auxiliary coupled inductor and a storage capacitor at primary side as well as the auxiliary winding and the auxiliary switch at secondary side, the proposed converter in this paper can not only achieve the ZVS operation in the entire line and load range but also reduce the conduction loss. Finally, the operational principle and analysis of the proposed converter are presented and verified by a 1kW/48V, 100kHz prototype.