Influence of grounding system modeling on Transient analysis of transmission lines due to direct lightning strike

Abstract

The aim of this paper is to implement different grounding system (GS) models in order to compare its influence on the calculation of overvoltages in transmission lines, produced by direct lightning strikes. The models studied were a lumped DC resistance, a non linear resistance, and a synthesized circuit based on the frequency response of the GS. The latest model is proposed by the authors and takes into account the frequency dependent transient behavior of the GS.The overvoltages simulations were carried out by means of the EMTP-ATP program.

La investigación del rayo en Colombia: Parámetros del rayo, sistemas de protección, evaluación de riesgos y sistemas de alerta

“…The main cause of transmission line failures is lightning, being the direct strike to shielding wires one of the most frequent origin of lightning overvoltages. Among other factors, the parameter with the biggest influence in the direct lightning strikes overvoltages is the Grounding System (GS) [40]- [42]. For this reason, some Colombian electric companies have centered their attention in the study of grounding systems in power systems and distribution networks [41]- [43].…”

“…In Rondon et al [42] and Montaña et al [43] an evaluation of the most suitable way to analyze transient phenomena in transmission lines using ATP/EMTP and applying two models of a transmission tower for the lightning-surge analysis was presented. In these papers, different GS On the other hand, Moreno et al [41] presented an electromagnetic model to evaluate the transient behavior of the grounding system and its effect in the calculation of lightning overvoltages.…”

Tower Models for Power Systems Transients: A Review

“…All these models assume that the tower supports a propagating TEM mode, i.e., the electromagnetic field to be a spherical wave, or that this mode represents the major contribution to the tower response. Other researchers presented non-uniform TL models: Randon et al [46], Saied et al [47] and Oufi et al [48] proposed modeling the tower as a non-uniform, lossless, exponential TL to be studied in the Laplace domain, with the characteristic impedance varying continuously along the tower. Correia de Barros and Almeida [49,50] investigated the propagation along a non-uniform lossy TL equivalent of the tower in the TD through FDTD methods.…”