Research On Time-domain Finite Difference Algorithm With Thin Wires In Electromagnetic Compatibility Environment

The main content of this paper is the time-domain finite-difference algorithm with thin wires.In FDTD,wires are usually modelled as perfect electric conductors by forcing all tangential electric field components on their surfaces to zero.For wires with very small cross-sections,a very high resolution grid is necessary in order to accurately model the wires.But FDTD with such a high resolution grid is prohibitively computational expensive.In order to model these small but important structural features with possible run time and few nodes.The thin-strut FDTD formalism by Holland et al.captured the effects of a thin wire present in the discretized three-dimensional space by introducing an “in-cell inductance” model of the wire.The wire was separated from the three-dimensional volume,and partial differential equations governing currents and charge densities on the wire were developed.Then the simultaneous,coupled equations for currents and charge densities were solved concurrently with the FDTD time stepping.We first introduce the basic thesis of the finite-difference time domain algorithm,and then make a detailed derivation of thin-wire model algorithm including the proposed new stability conditions.The free-space thin wire model is simulated.Through research,we can get the quantitative coupling characteristics of different lengths of thin wires for different electromagnetic pulses.In order to study the effect of mutual inductance between wires,this algorithm is extended to a multi-conductor model,and the causes of these phenomena are analyzed.The law of electromagnetic pulse coupling to thin wires is obtained.Finally,the problem of thin-wires is extended to modeling in large-scale electromagnetic systems,and the interaction between thin-wires and the entire environment is studied.We use the CST simulation software to simulate the model and compare it with the numerical calculation results of the thin-wire FDTD algorithm,which verifies the correctness of the algorithm and the advantage of the calculation speed.These calculation results are of great significance for studying the electromagnetic interference related fields such as the impact of electromagnetic pulses on transmission lines,cables,and wires in the system.