改进型移相全桥PWM ZVS DC—DC变换器的研究

An Improved Phase-shift Full-bridge PWM Converter

本文提出了一种副边加箝位网络的改进型移相全桥ZVS PWM DC-DC变换器。该箝位网络减小了移相全桥变换器续流状态时的原边环流,在宽负载范围内实现了滞后桥臂的ZCS开关,并可有效地减小副边整流二极管上的振荡尖峰。文章详细分析了变换器的工作原理及各个工作模态。在此基础上,研制了一台输出功率3kW(360V/8.5A)的DC-DC变换器样机,实验结果表明,理论分析正确,变换器整机的变换效率高。

This paper introduce an improved phase shift ZVS-PWM converter. A simple auxiliary circuit, which consists of two small capacitors and three diodes, is added in the secondary to decrease the circulating current,as well as to clamp secondary rectifier voltage. The convertor achieves zero-current switching for the lag leg due to the minimized circulating current. The principle of the convener and the operation modal are analysied in detail. A 3kW DC-DC converter is designed based on this circuit. The experiment result verify the analysis .and the efficiency of the converter is high.