New Two-Transformer Phase-Shift Full-Bridge Converter With Low Conduction Loss

초록

A two-transformer phase-shift full-bridge (PSFB) converter has features of zero-voltage switching (ZVS) capability, clamped voltage stress of the primary switches. However, when a wide input voltage range is required, the two-transformer PSFB converter operates with extended freewheeling mode. In addition, a large freewheeling current is reflected on the primary side, which causes a large circulating current. As a result, the freewheeling current flows through high voltage rating diodes, resulting in a large conduction loss. To overcome this problem, a new two-transformer phase-shift full-bridge converter with low conduction loss is proposed in this paper. By employing a diode which has a low voltage stress in the secondary side, the proposed converter eliminates the circulating current in the primary side. As a result, the proposed converter reduces the primary and secondary conduction loss. The effectiveness and feasibility were verified with a 300-400 V input and 12 V/400 W output prototype. © 2023 The Korean Institute of Power Electronics.

키워드