The Test And Diagnoses System Of The Conducted Interference

With the application of the electric productions and the electronical productions, conducted interference has become a kind of social effects of pollution. It not only disturb other electronical equipments nearby, but also threaten the health of the humen. The conducted interference can be divided into two types: the common-mode interference and the differential-mode interference. The EMC only tests the general conducted interference ,and dosen't take any easures to distinguish the two types of interference. But actually, the two types of interference exist in all of the EUTs., and one of them is dominant. If users know which one work, and its level, they can find the origin of the interference, adopt the appropriate steps, choose the correct EMI filters to solve the problems. With the maturity of the EMC rules at home and abroad, how to reduce the electromagnetic interference, improve the EMC capability of the electronical productions has become important for the possession of the market, the cuts of the exploiture period and the reduction of the cost. As the research indicates, the conducted interference producted by the electronical productions can be reduced to the level not preponderates over the EMC standard. The EMI filter is the efficient component makes the electronical equipments accord with the EMC standard.EMI filter is the basic method to restrain the electromagnetic interference of the electric productions and the electronical productions. But the actual capability of the EMI filter is not only determined by its own parameters, but also by the radio- impedance of the electric net., the interference source inside the equipment, and the transmitted impedance of the electromagnetic interference. The engineer will meet many intractable problems during the application of the EMI filter. If they choose the existing filters, the capability of the filters was measyred under the condition of 50Ω. It didn't accord with the actual condition for the users. The exact description of the conducted interference of the electric productions and the electronical productions is important for the hold of the electromagnetic interference of the electronical equipments, the restraint of the electromagnetic interference, and the boost of the design of the EMC. Aiming at the existing problems during the test of the conducted interference and the design of the filter, I analyse and design a test and diagnosis system for the conducted interference. I analyse the signal of the conducted interference in theory, and design the separation net. Besides, I design the correction software considering the error of the test. I also design the software for the design of the filter. It would be guidance for the elimination of the conducted interference...