Cancellation Technology Based On New Plane Parasitic Passive EMI Filter

Increasing frequency switching power supply, discrete EMI filter large volumes in which the parasitic inductance, parasitic capacitance parameters to some extent interfere with the high frequency characteristics of the circuit in which the high-frequency characteristics are more serious electromagnetic interference, in which EMI filter eliminates action will reduce the high frequency characteristics of the switching power supply to a certain extent.EMI filter structure of this paper is made using discrete integrated structure, from reducing the volume and improve the power density is proposed to increase the angle of the way to reduce the influence of parasitic elements, and the like by PSpice simulation software equivalent model parameter simulation study, and test prototype verification analysis, the analysis shows that this type of structure is low parasitic filter parameters to meet certain requirements in engineering, can obtain higher frequency performance, the element volume also significantly less.The main work can be summarized as follows:(1) introduces the research background and an overview of related applications EMI filter in power electronics development planar integrated EMI filter development conditions.(2) Then using the principle of magnetic circuit analysis, were analyzed to eliminate the principle of the integrated EMI filter inductance analysis, the establishment of a two-port network theory and equivalent circuit model is proposed to eliminate the principles of the model parameters and elimination, and electromagnetic field Finite element calculation and experimental testing method of extracting the electromagnetic parameters, derived a formula for calculating the insertion loss, insertion loss curves give the model, and analysis of experimental verification.(3) The difference between the common mode inductance EMI filters planar structure of the special structure to obtain planar integrated circuit inserted inductance integrated structure, the use of the plane passive integrated approach, making the experimental prototype, simulation results and experimental analysis proves the effectiveness of the filter circuit eliminate methods.