移相全桥变换器中整流电压应力机理研究

A Rectifier Voltage Stress Mechanism in Phase-shifted Full-bridge Converter

提出一种简单有效的方法来缓解移相全桥(PSFB)变换器整流电压应力,且能提高传统PSFB变换器总体效率。前提是PSFB零电压开关(ZVS)变换器的等效电路在电压振荡期间可视为一个五阶模型,由此,可通过改变寄生参数来调节整个整流器振铃电压幅值。当整流器的振铃电压能被抑制在一个可接受范围内时,则有可能完全去掉RC缓冲电路来提高效率。240 W(10 A,400 V/24V)实验模型电压应力减小了15 V,效率增加了2%。

A simple and effective method is proposed to release the voltage stress of phase-shifted full-bridge （PSFB） co-nverter and improve overall efficiency of the conventional PSFB converter.This method is based on the equivalent cir-cuit of the PSFB zero voltage switching （ZVS） converter during the voltage oscillation period can be treated as a fifth-order model, and the amplitude of the voltage ringing across the rectifier can be retrained by adjusting the inductor inthe primary-side.h is even possible to remove the RC snubber circuit completely to improve the effficiency,the volt-age stresses of the rectifier can still be limited in an acceptable level.Reduction of 15 V voltage stress and incrementof 2% efficiency can be obtained in the 240 W（10 A,400 V/24 V） experimental prototype.