Conductive Emi Noise Diagnosis And Inhibition Of An Integrated Approach To Research

As so many conducted EMI problems emerge in our life and EMC standards are excuted compulsively, people now attach importance to EMC problems over again. How to do noise diagnosis and suppression, and to set up an intellectual system both technical and economical is still a problem to research.Several conducted EMI noise diagnosis technics are described in this paper, and research is mianly done on four noise diagnosis networks. By experimental analysis and simulation, network which has the best performance is picked out. Taking example by Switch Mode Power Supply, this paper analyzes the transmittted route of conducted EMI noise, dose modeling of noise source impedance and tests it in both two current probes method and single current probe method, sets up its circuit model, which is very helpful for filter design. Next, EMI filter is designed for noise suppression. Based on CM , DM nosie and their noise source impedance, EMI filter is designed through network analytical method. After that, an intellectual system of conducted EMI noise diagnosis and suppression is set up, which is consisted of hardware and software. Experimental results show that the system could do noise diagnosis and suppression efficiently. At last, research is done on decision making of this intellectual system. It aims to choose a best nosie disposal scheme by decision making, not only to satisfy technical standards, but also to decrease economic cost mostly, making the technic and economy a whole.