The Influence Of Electrostatic Discharge To The Field In The Metallic Enclosure

Because of the rapidly development of electrical and electronic technology，theresearch of influence from electrostatic discharge to various equipment has become animportant issue in the field of electrical. At the same time, there inevitably exists theholes and seams caused by ducts and display screen on electrical equipment. Becauseof these holes and seams in the metallic enclosure, there will be electric ifeld coupling.So the research of electromagnetic interference in equipment is very important.In the paper, the main theory of the calculation of ESD analysis principle issummarized. Various ESD coupling path and the current of ESD are analyzed. Thecalculation of the ESD calculation method is listed. The iterative equations of theifnite difference time domain and the boundary conditions are deduced.To research the influence of the metallic enclosure bean tested to ESD radiationifeld, we use the finite difference in time domain to calculate the radiation field withor without a metallic enclosure. To research the influence of coupling field inside ofthe metallic enclosure caused by the size of the hole on the metal shielding body andthe distribution of the hole, when the metallic enclosure is placed, magnetic fielddistribution been changed very greatly, maximum of magnetic field been strengthenbetween the VCP and EUT，but magnetic field at the side away from EUT is beenweakened. We calculate the radiation field in the metallic enclosure with variousshape of single hole of the same area, the magnetic field is the minimum when there isa round hole on the metallic enclosure, square next, rectangular strongest. Researchthe metallic enclosure with a single narrow gap with different short edges, comparethe radiation ifeld of the metallic enclosure with different numbers of circular holearray and with different numbers of same narrow gap. Along with the increase of thenumber of holes the coupling ifeld reduce，with the decrease of the narrow gap widththe coupling field reduce，along with the increase in the number of narrow gap shellinternal coupling field increased.