移相全桥ZVS直流变换器研究综述

摘要：移相全桥ZVS(Zero Voltage Switching)直流变换器具有工作频率恒定、拓扑结构简单、功率密度高且能利用器件自身的寄生参数谐振实现ZVS等特点，在中高功率应用场合中备受青睐。然而，传统移相全桥ZVS变换器软开关范围有限，存在环流损耗、副边占空比丢失以及整流桥寄生振荡等缺陷。本文对移相全桥ZVS变换器存在的问题进行分析，针对典型的拓扑结构和调制策略进行分类，比较了各方案的优势与不足，并提出一种基于互补占空比的改进方案，建立模型并进行仿真验证。

Review of Research on Phase-shifted Full-bridge ZVS DC-DC Converter

Abstract: Owing to their characteristics of constant frequency operation, simple topology, high power density and utilizing the resonance between their own parasitic parameters to realize Zero Voltage Switching(ZVS), phase-shifted full-bridge ZVS DC-DC converters are favored in medium- and high-power applications. However, the conventional phase-shifted full-bridge ZVS converters still have drawbacks such as limited soft switching range, loss of circulating current-related power, loss of secondary-side duty cycle, and parasitic oscillation on rectifier diodes. These drawbacks lead to the limitation of their optimization performance, which also becomes a hot issue that scholars are trying to explore. In this paper, the existing problems in phase-shifted full-bridge ZVS converters are analyzed. The typical topological structures and modulation strategies are classified, and the advantages and disadvantages of each scheme are compared by combining the corresponding characteristics. On the basis of the above summary, a novel improved scheme based on complementary duty cycle is proposed. Finally, a model is built and simulated to verify the feasibility of the proposed scheme.