全桥移相变换器的开关电源设计

Design of Shift Full-bridge Phase Converter Switching Power Supply

全桥移相变换器ZVS作为一种性能优秀的变换器,前后两个桥臂的开关管都在零电压软开关条件下运行,开关功耗小,结构和控制也简单,符合了现代开关电源小型化、高频化的发展趋势,因此在中大功率场合得到了广泛的使用和研究。但是,在使用和研究的过程中,也发现移相全桥变换器ZVS存在副边占空比丢失和整流桥寄生振荡等问题。重点分析这些关键问题产生的原因,给出相应的解决方案。

ZVS phase-shifted full-bridge converter as an excellent phase-shifted full-bridge converter,two bridge arm switch to run in the zero-voltage soft-switching conditions,the switching loss is small and simple structure,and control is also simple, in line with the trend of development of small switching power supply,high frequency,a wide range of research and appli- cation of occasions in the high-power DC/DC converter.However,in the use and course of the study also found that phase-shifted full-bridge ZVS converters existence of the secondary side duty cycle loss and rectifier bridge parasitic os- cillation problems.This paper focuses on analyzing the causes of these key issues, and gives a reasonable solution.