Resposta Dinâmica de Linhas de Transmissão Submetidas à Combinação de Ventos Convectivos e Sinóticos

Vanessa Vanin¹; Leandro Fleck Fadel Miguel¹

¹ Federal University of Santa Catarina

doi:10.20906/CPS/CILAMCE2017-0519

Resumo

Numerous failures of transmission lines are linked to the occurrence of Thunderstorms. The localized nature of this type of meteorological event is particularly damaging to large structures, as in the case of transmission lines, because it generates uneven distributions of forces. In this context, this work proposes to analyze the dynamic nonlinear geometric response of a section of transmission line composed of a tower and two spans of adjacent cable. This section of LT will be subjected to the loadings coming from some scenarios of combinations between downbursts and synoptic winds. The model of wind velocity fields during thunderstorms, described by Ponte (2005) and Ponte and Riera (2007), adapted by Miguel and Riera (2013), and later by Gheno (2014) and Gheno, Menezes and Miguel (2015), was adopted in this work, because it is based on meteorological variables, which are susceptible to statistical evaluation. For the same wind speed at a height of 10 m above the ground, the response of the cables and the lightning rods presented the highest value in the case in which the synoptic wind is perpendicular to them, which consequently also generated the greatest effort the tower uprights. In the other cases, in relation to the cables combinations between bottom wind and downburst could generate greater efforts. However, in the analyzed tower uprights, maximum forces always occurred in the presence of synoptic wind only, because all the cables are exposed to the same wind load, unlike what occurs during downbursts, which induce localized and unequal loads.

Palavras-chave: High Intensity Winds; Wind Action,; Downbursts; Transmission Lines; Synoptic Wind