华南理工大学学报(自然科学版) ›› 2003, Vol. 31 ›› Issue (1): 60-64.

• • 上一篇    下一篇

正激式变换器轻载条件下的同步整流分析

谢运祥 王 浩   

  1. 华南理工大学 电力学院‚广东 广州510640
  • 出版日期:2003-01-20 发布日期:2022-04-07
  • 通信作者: 谢运祥 (1965-)‚男‚博士‚教授‚主要从事电力电子技术的研究.
  • 作者简介:谢运祥 (1965-)‚男‚博士‚教授‚主要从事电力电子技术的研究.

Synchronous Rectifier Analysis of Forward Converter under the Condition of Light Load

Xie Yun-xiang Wang Hao   

  1. College of Electrical Power ‚South China Univ.of Tech.‚Guangzhou510640‚China
  • Online:2003-01-20 Published:2022-04-07
  • Contact: 谢运祥 (1965-)‚男‚博士‚教授‚主要从事电力电子技术的研究.
  • About author:谢运祥 (1965-)‚男‚博士‚教授‚主要从事电力电子技术的研究.

摘要: 针对具有同步整流的正激变换电路在轻载条件下‚因输出滤波电感电流经同步整流 MOSFET 管反 向流动而形成环流的现象‚提出了利用 UC3842检测轻载条件‚并通过禁止续流 MOSFET 导通来阻止电感 反向电流的技术方案‚理论分析和实验研究证明该方法是可行的‚并且能明显提高变换器轻载运行时的变换 效率.

关键词: 正激变换器, 同步整流, 开关电源

Abstract: While the converter works at light load‚the output filter inductor current will go negative through MOSFET in synchronous rectifier and the circulating current will be formed.In order to solve this problem‚the detection method of light load condition of converter used by UC3842is proposed in this paper‚meanwhile‚the technique has also been studied which is used to make the inductor current cannot be flow negatively by switching off the MOSFET while converter works at light load.The theory analysis and experiment have proved that the proposed method is effect‚the converter efficiency has also been improved a lot at light load. 

Key words: forward converter, synchronous rectifier, switching mode power supply

中图分类号: