Dual-Transformer-Based Hybrid Phase-Shift PWM DC-DC Converter With Wide ZVZCS Range

This brief proposes a dual-transformer-based hybrid phase-shift full-bridge (PSFB) converter. Instead of adopting auxiliary components, the proposed hybrid PSFB converter widens the zero-voltage switching (ZVS) range with the help of the current generated by additional transformer and additional half-bridge. Unlike the conventional method utilizing auxiliary circuit, the additional transformer and half-bridge can also transmit a large part of the power to reduce the burden on the main transformer. Meanwhile, the circulating current on the primary side can be effectively reduced due to the structure of hybrid bridge, and the additional half-bridge can achieve zero-current switching (ZCS) with reduced switching loss. The proposed converter can obtain a wide ZVZCS range with simple phase-shift pulse width modulation under fixed switching frequency. The operating principle, ZVZCS performance, and parameter design are analyzed in this brief. Finally, a 1 kW experimental prototype was built to verify the effectiveness of the proposed solution.