具全區域零電壓切換範圍之全橋相移同步倍流轉換器分析與設計

Analysis and Design of a Full-Range Zvs Phase-Shifted Full-Bridge Converter with Synchronous Current-Doubler Rectifier

本文提出一具全區域零電壓切換範圍之全橋相移同步倍流轉換器，於變壓器二次側使用同步整流技術取代整流二極體，僅須簡單之邏輯電路驅動，即具有全負載零電壓切換範圍與同步整流之優點，不須外加複雜之輔助電路，可提升轉換器效率。本文依轉換器之操作模式分成正－連續導通模式、正－臨界導通模式、負－連續導通模式與負－臨界導通模式。藉分析此四種操作模式，探討轉換器參數與全橋主開關之全負載零電壓切換範圍關係。最後以一輸入電壓為200V，輸出電壓為12V，輸出功率為250W之轉換器，以實驗結果驗證此理論分析之正確性與可行性。

This paper proposes a phase-shifted full-bridge converter with synchronous current-doubler rectifier for full-load range zero-voltage switching (ZVS), the proposed converter only uses a synchronous rectifier to replace rectifier diodes in the secondary side of the phase-shifted full-bridge with a current-doubler rectifier. You do not need to add the complicated auxiliary circuit, just adopt a simple logic circuit to derive the signal for driving the synchronous rectifier. It can achieve full-load range zero-voltage switching (ZVS) and can increase efficiency of the converter. The operating mode of the converter divided into positive continuous conduction mode (PCCM), positive boundary conduction mode (PBCM), negative continuous conduction mode (NCCM) and negative boundary conduction mode (NBCM). According to the analysis of the four modes of the theoretical operations, the relationship between the major switches of the full-bridge for full-load range zero-voltage switching (ZVS) and each circuit component parameters of the converter are discussed. Finally, a prototype of full-load range ZVS phase-shifted full-bridge with synchronous current-doubler rectifier with an input voltage of 200V, output voltage of 12V, and output power of 250W are developed to verify the correctness and feasibility of this analysis of the four operating modes.