Estudio del comportamiento de líneas de transmisión frente al impacto directo de rayo utilizando diversas configuraciones de pararrayos de línea. Estudio de caso colombiano

Abstract

Colombia is a tropical country characterized by its extreme climatic conditions, topographic and orographic diversity. This causes intense lightning activity in the country, which is reflected in high densities of discharges to ground, elevated keraunic levels and high peak lightning currents. As a result of these conditions, the population is exposed to risk and the damage to electrical systems is frequently reported. Due to, great economic losses and social impacts are caused. Part of this problem are the outputs and failures of the national interconnected system assets. Therefore, studies associated with quantifying and evaluating the harmful effects of lightning must be developed to comply not only with adequate safety conditions, but also with the CREG reliability and regulation standards. In this way, this degree work analyzes the transitory behavior of a Colombian typical double circuit transmission line. For this, a test system was implemented in the ATP/EMTP© software with reference to the Copey Fundacion line # 2, which has operated since 2020 at 220 kV. In this system, three case studies are developed including different configurations of arresters and variables such as: the magnitude of the lightning current, the tower footing resistance, and the instantaneous phase voltage. With these factors, the appearance of back flashover (BFO) and dissipated energy by the arresters are analyzed. The results show that the energy and phases with BFO depend on the selected study variables, especially a high tower footing resistance and the magnitude of the lightning current. With the results it´s possible to understand the effects of including line surge arresters (LSA) in transmission lines. Likewise, as part of the investigation results, to maintain the service continuity the installation of LSA in one, two or three phases of the same circuit is recommended. As well, design suggestions for lightning protection levels I, II, III y IV are given, and future researchers are suggested.