电力线通讯辐射噪声的预估与抑制

Prediction and suppression of radiated EMI noise in power line communication

介绍了电磁干扰(EMI)噪声分离网络在预估与抑制电力线通讯中系统辐射电磁干扰噪声方面的应用.首先,利用电磁干扰噪声分离网络对电力线通讯系统中的电磁干扰总噪声进行模态提取,获得该噪声中的共模分量和差模分量,并根据相应的数学模型将测量得到的噪声电压信号转化为噪声电流信号.然后,利用共模噪声电流与辐射场的关系模型对系统的电磁干扰辐射噪声进行预估.实验结果表明:通过提取引起辐射噪声的共模噪声电流,可较为准确地预估此辐射噪声;通过设计相应的EM I滤波器或采用铁氧体磁环,可实现对共模噪声电流的抑制,从而达到抑制系统中辐射电磁干扰噪声的目的;与滤波器相比,铁氧体磁环抑制辐射噪声的效果更为明显.

The electromagnetic interference(EMI) noise separating network is used to estimate and suppress the radiated electromagnetic interference noise in a power line communication system.First,the common mode noise and different mode noise can be extracted from the electromagnetic interference noise in a power line communication system by the electromagnetic interference noise separating network.The noise voltage signal can be transformed into the noise current signal by a mathematical model.Then,the radiated electromagnetic interference noise can be estimated using a model based on the relationship between the radiated electromagnetic field and the common mode current.The experimental results show that the radiated electromagnetic interference noise can be estimated exactly by extracting the common mode noise current which causes the noise.The common mode noise current can be suppressed by designing an EMI filter or using a ferrite core,which induces the suppression of the radiated electromagnetic interference noise in the power line communication system.Moreover,the suppression by the ferrite core is more effectively than that by the EMI filter.