移相控制全桥变换器的分析

Analysis of Phase Shifted Full Bridge Converter

移相控制全桥变换器利用变压器的漏感和功率管的寄生电容来实现零电压开关，同时又实现了ＰＷＭ控制，而不需要增加缓冲吸收电路。该变换器电路结构简洁，控制电路简单，是中大功率直直变换场合的理想电路拓扑之一。本文分析这种变换器的工作原理，讨论实现零电压开关的条件，以及副边占空比丢失的原因，并给出仿真和实验结果。

Phase shifted full bridge converter (PS FB converter) utilizes leakage inductance of main transformer and output capacitor of power switches to realize zero voltage switching (ZVS) of power switches and PWM control without any snubber circuit, which is simple both in topology and in control and is suited for middle to high power dc to dc conversion applications. This paper analyzes the principle of PS FB converter, discusses the differences of the realization of ZVS for leading leg and lag leg. Secondary duty loss is the peculiar characteristics of PS FB converter. The simulational and experimental results are also given.