EFFECTIVE NUMERICAL APPROACH TO TRANSIENT PHENOMENA INDUCED IN GROUNDED TRANSMISSION LINES

摘要

The aim of this paper is to present a numerical approach that lead to the design and then to the development of a suitable numerical software tool in order to consider effectively the transient phenomena induced by the action of external electromagnetic fields impinging on grounded multiconductor transmission line structures, G-MTL. The external interfering electromagnetic fields here considered are typical lightning induced phenomena, and in particular both direct and indirect stroke will be addressed. The algorithm stands first of all on the discretization of the set of differential equations, in the frequency domain, modeling the G-MTL behavior, even considering non-homogeneous lines, or the introduction of lumped loads and/or generators even in different points along the multiconductor line itself. The set of discretized equations is then solved just for the excited subset of frequencies of interest and finally the solution is rephrased in the time domain. Some numerical examples of particularly significant test cases, such as the indirect stroke of an optical fiber cable and the direct stroke on a real three-phase line, are here reported showing the effectiveness of the considered approach.