摘要
三明治绕法通常用来增大变压器初、次级绕组之间的耦合系数,减小漏感,提高电源整体效率。但该方法往往会恶化共模传导电磁干扰。本文基于次级绕组净感应电荷的理论模型,深入分析了屏蔽体接地点位置及屏蔽高度对变压器共模传导EMI的影响。提出在反激变压器采用三明治绕法的同时,调节屏蔽层与次级绕组之间间距的方法来兼顾整个系统的效率和电磁兼容问题。采用优化设计的反激变压器使得系统的效率提高2.31%,共模传导EMI改善了15d B。实验结果验证了理论分析的正确性和实际有效性。
Sandwich winding is often used to reduce the transformer losses because of increasing the coupling coefficient transformer between primary winding and secondary winding and reducing the leakage inductance. But it tends to worsen common-mode electromagnetic interference. This paper analyzes the common-mode electromagnetic interference characteristics of the transformer by changing the height of Shield and the location of grounding point based on the model of induced charge in the secondary side. Sandwich winding is used, while using some shielding and adjusting spacing between shield and the secondary winding to improve transformer common-mode electromagnetic interference characteristics are proposed. By means of optimization design of common-mode electromagnetic interference and efficiency of the Fly-back transformer, the prototype is manufactured and tests are carried. The results show that the efficiency is improved by 2.31%, and common-mode electromagnetic interference is reduced by 15 d B. Finally, the model is verified with experimental results.
出处
《电气技术》
2015年第10期8-12,44,共6页
Electrical Engineering
关键词
反激变压器
效率
共模传导EMI
优化设计
fly-back transformer
efficiency
common-mode electromagnetic interference
optimization design
