移相全桥ZVS变换器整流桥寄生振荡的抑制

Restraining Methods for Parasitic Oscillation in PS-FBZVS Converter

移相全桥零电压开关(ZVS)变换器是应用于中大功率DD-DC变换场合的理想拓扑之一,但在其输出整流二极管反向恢复时,整流桥产生寄生振荡,二极管上存在很高的尖峰电压。这将带来电路损耗,并影响整流桥的使用寿命。本文分析了振荡产生的原因,并介绍了抑制的方法。重点分析了一种原边加箝位二极管的缓冲电路形式,制做了一个5.5kW样机,并给出了对比实验结果。

There exists a problem of the Phase-shifted full-bridge zero-vohage-switching（PS-FB-ZVS） PWM converter,which is widely used at medium and high power levels, that the output rectifier diodes suffer the parasitic oscillation and voltage spike resulted by the reverse recovery of the rectifier diodes. In this paper, the reasons and restraining methods are discussed, and a novel ZVS converter is proposed which adopts two clamping diodes in the first side of transformer. The operation principle of the novel converter is analyzed and the experimental results of a 5.5kW prototype converter are also given.