高频开关电源电磁兼容研究

High-frequency Switching Power Supply EMC Research

在高频开关电源电路中,经常会产生复杂的电磁干扰,因此,满足国际法规电磁兼容性是至关重要的。该文介绍了一种具备良好电磁兼容性的高频开关电源系统方案。通过分析高频开关电源产生电磁干扰传导骚扰的原因,该文对传导骚扰的传播路径进行了探究,并对产生干扰信号的线路以及元器件采取新型抑制措施,截断或改变了产生传导骚扰的路径。此外,本方案中还进行了线性阻抗稳定网络LISN测试,最后得到满足国际标准规定的电磁兼容EMC问题的高频开关电源设计。经测试结果表明,该方案设计可以在频率20MHz处通过EN55022B标准中规定的CLASS B限制要求。

In the high-frequency switching power supply circuit,complex electromagnetic interference often occurs.In view of this problem,it is crucial to meet the electromagnetic compatibility in accordance with the international regulations.A design of high-frequency switching power supply system with good electromag- netic compatibility is introduced in this paper.By analyzing the reason why high-frequency switching power supply generates electromagnetic interference,the propagation path of conducted emission is studied and new suppression measures are adopted in circuits and components that may generate interference signal, so that the path of conducted emission can be truncated or changed.Moreover,the linear impedance stabi- lization network LISN test is also carried out in this design,and the high-frequency switching power supply design that can meet international standards for electromagnetic compatibility EMC problems is finally achieved.The test result shows that this design can meet the CLASS B limits of EN55022B standards in the frequency of 20MHz.