Analysis Of Induction Characteristics Of Transmission Line Under Strong Electromagnetic Pulse Environment

Strong electromagnetic pulse,with the characteristics of high energy,wide frequency band and wide coverage area,can be coupled into electronic equipment/system through front door coupling path and back door coupling path,For this reason,it causes irreparable losses.This powerful destructive force is not only highly concerned in the military field,but also concerned in the people's livelihood.Therefore,the coupling effect of strong electromagnetic pulse and strong electromagnetic pulse protection have become one of the most important research topics in modern times.In the paper,based on the finite difference time domain(FDTD)method and BLT equation,at the same time,combining with transmission line theory,the electromagnetic coupling law of transmission lines in the different circumstances is solved and analyzed under strong electromagnetic pulse.The problem of electromagnetic protection and reinforcement under special circumstances is discussed.The details go as follows:Firstly,the generation principle of thunder-and-lightning and High-altitude Nuclear Electromagnetic Pulse(HEMP),the common standard time domain waveform and its potential destruction capability are introduced in the paper.Secondly,the electromagnetic induction characteristics of the transmission line inside the building irradiated by HEMP pulse were studied by usage-circuit combination method,and the effects of the incidence direction,polarization and height on the induced current were analyzed.Thirdly,The derivation process of BLT equation under different conditions is introduced in detail,and the solution of coupling effect of single conductor transmission line,multi-conductor transmission line,terminal connected with nonlinear load transmission line and transmission line in half-space with different ground conductivity is given.Finally,in view of electromagnetic pulse protection,this paper introduces the type of grounding wire and grounding mode,compares the difference of power line arrangement modes,simulates the electromagnetic induction characteristics of strong electromagnetic pulse in and out of the shielding layer,and analyzes the shielding effect of the shielding layer.