Melhoramento da malha de aterramento da linha de transmissão CL1

Abstract

Unscheduled shutdowns that occur in a transmission line constitute an important parameter in defining its performance, with atmospheric discharge being the main electromagnetic event responsible for such occurrences. The grounding mesh plays a fundamental role in dissipating fault currents, ensuring operational safety and equipment integrity. One of the important methods related to the grounding of transmission lines is the reduction of the grounding resistance of the structures, it is known that this constitutes one of the effective means of controlling overvoltages caused by atmospheric discharges and also the system's surge currents. Based on this information, field measurements were made of the grounding resistance of the counterweights and the resistivity of the soil, where it was possible to verify through the results that some towers presented values that exceeded the standardized values. Collecting this information is the main focus of this study, which aims to provide support for the identification of towers that present resistance above the normalized value. In this work, the main physical aspects and appropriate methodologies for analyzing grounding are evaluated, with more specifically studying techniques to reduce grounding resistance, as well as grounding measurement routines and calculations involved in the process of obtaining data.