Analysis and Design of a High-Frequency Isolated Full-Bridge ZVT CLL Resonant DC–DC Converter

In this paper, a new pulsewidth modulated gating scheme and a zero-voltage transition (ZVT) auxiliary circuit is proposed for a fixed frequency full-bridge CLL dc-dc resonant converter with a capacitive output filter. An approximate complex ac circuit approach is used for the steady-state analysis of the converter. The optimum design of the converter is described with the help of design curves for a sample converter of 200-W power rating operating at a switching frequency of 100 kHz. The converter with applied gating scheme and ZVT auxiliary circuit provides zero-voltage switching to all the switches for the entire variations in loading and input voltage conditions ensuring higher conversion efficiency. PSIM simulations are carried out to verify theoretical predictions about the performance of the converter for various operating conditions. Finally, experimental results are provided to verify the feasibility of the proposed converter. The theoretical, simulation, and experimental results are given and discussed.