Investigações relativas ás linhas de transmissão horizontal e vertical de perdas elevadas

Abstract

This document presents the laboratory measurements and time and frequency domain simulations and calculations regarding the high loss horizontal and vertical transmission lines aiming at improve the knowledge of their performance and well understand the electromagnetic interaction between the lightning channel and the electrical facilities. Impulsive and harmonic 5 MHz to 100 MHz signal generators, were used for the high losses transmission lines excitation. The lines were mounted with series resistors. The laboratory tests were done in the Extra High Voltage Laboratory of the Federal University of Minas Gerais, in the Antenna Laboratory of the Catholic University of Minas Gerais, and in FIAT Shielded Anechoic Electromagnetic Chamber in Betim, Minas Gerais. For the measurements, digital osciloscopes and network analyser were used. The softwares 'Orcad' and 'Mathcad' with its Fast Fourrier Transform and the Inverse Fourrier Transform functions were used respectively for time and frequency domains simulations, The experimental results were compared with the calculations, allowing the proposition of suitable models for horizontal and vertical high losses transmission lines, including impulsive and harmonics current distribution and propagation parameters.