On the Effects of EMI and the Soil Structure on Transmission Line Parameters — Part I: Theoretical Model

Abstract

This paper presents a methodology for computing the electrical parameters of overhead transmission lines accounting for metallic pipeline interferences and soil stratification effects. The method is based on the closed-form analytical solution of the Carson’s integral, which is used to calculate self and mutual line parameters. Obtained results reveal that zero sequence impedances may be significantly affected by uncertainties due to metallic pipeline interferences and soil layered structure, thereby a more robust line parameter calculation in practical applications is required to avoid errors in line design which uses zero sequence as fundamental parameters. In a companion paper, the methods developed discussed in this part are employed to evaluate a wide variety of fault scenarios on a 230 kV transmission line 200 km long, 60 Hz, considering a hypothetical case of interferences with a metallic pipeline and soil stratification based on resistivity measurements.