Modulated-Coupled-Inductor-Based ISOP Phase-Shifted Full-Bridge Converter With Wide ZVS Range and Reduced Duty-Cycle Loss

This article proposes a modulated-coupled-inductor-based input-serial-output-parallel (ISOP) phase-shifted full-bridge (PSFB) converter. Instead of using the variable saturation inductor in conventional method, the adoption of modulated-coupled-inductor simplifies the control complexity without additional auxiliary circuits. The equivalent leakage inductance of the converter is determined by the operating phases of the two modules. Therefore, it can be easily changed by modulating the phase difference between the two modules to achieve zero-voltage switching (ZVS) at light load condition and reduce duty-cycle loss at heavy load condition. The proposed topology, operating principle, and the characteristics are analyzed in this article. Finally, the experimental results have verified the realization of ZVS, and the comparison with the traditional converter have verified the wide load regulation range.