虑及互耦效应的线缆辐射EMI建模

Radiated EMI Modeling of Cables Considering Mutual-coupling Effect

并行布线结构的开关电源线缆是开关电源辐射电磁干扰EMI(electromagnetic interference)的重要干扰源。针对并行线缆间辐射场互耦效应机理不明晰使得辐射电磁干扰预测不准确的问题,提出1种虑及线缆间互耦效应开关电源线缆的辐射电磁干扰模型。通过对描述线缆互耦效应的互阻抗建模,得到描述开关电源线缆辐射特性的辐射EMI输入阻抗模型,进而得到虑及互耦效应开关电源线缆的辐射EMI模型;搭建辐射EMI测试实验平台进行测试。实验结果表明,所提虑及互耦效应的辐射电磁干扰模型能够更为准确地预测开关电源线缆的辐射电磁干扰。

The cables of switching power supply which are connected in parallel is an important radiated electromagnetic interference(EMI)source for the switching power supply.Aimed at the problem of inaccurate prediction of radiated EMI of cables connected in parallel due to an unclear mutual-coupling effect,a radiated EMI model of cables of switching power supply is proposed by taking into account the mutual-coupling effect between cables.Through the modeling of mutual-impedance which describes the mutual-coupling effect between cables,the radiated EMI input impedance model describing the radiation characteristics of cables of switching power supply is obtained.Then,the radiated EMI model of cables of switching power supply is obtained considering the mutualcoupling effect.Finally,an experimental platform for measuring the radiated EMI was built,and experimental results show that the proposed radiated EMI model which takes the mutual-coupling effect into account can predict the radiated EMI of cables of switching power supply more accurately.