全桥软开关电路滞后臂性能的改进与研究

Research and Improvement on the Lag Bridge in Full-Bridge Soft-Switch Converter

在全桥PWM调制加移相控制的DC/DC变换器中,滞后臂比较难以实现零电压开关(ZVS),针对这一问题提出了相关的解决方案,并对一种带有无源谐振电路比较实用的电路进行了详细地分析,给出了在一个工作周期中的工作过程及其波形。对改进前和改进后的电路和输出波形进行了分析。结果表明,使用无源谐振电路确实能够增加整个系统的稳定性,降低系统的损耗。

In a PWM plus phase-shift control DC/DC converter,it is very hard for the lag bridge to achieve zero voltage switch（ZVS）. Several schemes are proposed to solve this problem. A practical structure with an auxiliary passive resonant circuit is analyzed,and the waveform and process during one duty cycle is presented. The waves of the PWM plus phase-shift con- trol DC/DC converter with and without auxiliary passive resonant circuit are compared. It is shown that the stability is enhanced and the loss is reduced with the application of the auxiliary passive resonant circuit.