Investigation And Design Of The Test 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. 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 source filter is the efficient component makes the electronical equipments accord with the EMC standard.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 doesn't use any methods to distinguish the two types of interference. That is the prevalent disfigurement in the actual test system of the conducted interference. Because the common-mode and the differential-mode are two separate parts during the EMI source filter's design. To different mode interference, there are different technologies to solve. If users know which one work, and its level , they can choose and design the correct EMI source filter to solve the problems.Aim at the prevalent disfigurement in the actual test system of the conducted interference, a test and diagnosis system for the conducted interference is designed in this paper. Firstly, the conducted interference is illustrated. Then the differences between the common-mode interference and the differential-mode interference are explained. Several actual test systems are enumerated. To solve the prevalent problem of these systems, a mode-separated system must be added. The mode-separated methods of the common-mode interference and the differential-mode interference are collected and compared. The most appropriate one is chosen and applied. The frequency characteristic bases the electrocircuit theory and simulated result bases PSpice show the feasibility of the noise separator.Considered the error brought by the instrument and the noise separator, the instrument corrected software and the noise separator corrected software are designed using C# and MATLAB. The spectrum of the common-mode interference and the differential-mode interference provided by this system would be guidance for the selection and design of the EMI source filter.