An improved FDTD thin wire model for conductors with an asymmetrical cross section

Large structural components may carry lightning current during a lightning strike. They could affect current distribution in wiring systems connected to electrical or electronic equipment. It is then necessary to model these wire structures correctly when performing lightning surge analysis. In this paper, an improved thin wire model for conductors with an asymmetrical cross section is investigated. The frequency-dependent loss is considered. The simulation results obtained by this model are validated with an analytical method. Three cross sectional shapes are tested. The cross section edges of these structures may not be necessarily in parallel to the FDTD grid lines. Good agreements are observed. It is found that the results of the proposed models generally have the errors of less than 0.5%.