Voltage oscillation elimination in output rectifier diodes in zero-voltage-switching PWM full-bridge converter: An overview

In the basic zero-voltage-switching (ZVS) full-bridge (FB) converter, the output rectifier diodes suffer from hard-switching, results in severe voltage spike and oscillation across the output rectifier diodes. In this paper, a fundamental approach is proposed to tackle this issue, indicating that clamping the voltage across the winding of the power transformer could eliminate the voltage oscillation in output rectifier diodes. According to the proposed approach, two basic clamping circuits are put forward, based on which, different clamping schemes in the previous publications can be derived and the relevance among them with respect to the structure of the circuit topology are revealed. Finally, a brief review and comparison is conducted on ZVS PWM FB converters with these different clamping schemes, which helps to further demonstrate the similarities and differences among these FB converters.