Impact of Frequency-Dependent Soils on Transient Responses of Lightning Protection System

Walter Luiz Manzi de Azevedo; Wagner Costa da Silva; José Luciano Aslan D’Annibale; Anderson Ricardo Justo de Araújo; Jaimis Sajid Leon Colqui; José Pissolato Filho

doi:10.20906/SBAI-SBSE-2023/3980

Walter Luiz Manzi de Azevedo School of Electrical and Computer Engineering, University of Campinas, SP
Wagner Costa da Silva School of Electrical and Computer Engineering, University of Campinas, SP
José Luciano Aslan D’Annibale School of Electrical and Computer Engineering, University of Campinas, SP
Anderson Ricardo Justo de Araújo School of Electrical and Computer Engineering, University of Campinas, SP
Jaimis Sajid Leon Colqui School of Electrical and Computer Engineering, University of Campinas, SP
José Pissolato Filho School of Electrical and Computer Engineering, University of Campinas, SP

DOI: https://doi.org/10.20906/SBAI-SBSE-2023/3980

Keywords: Electromagnetic transients, lightning protection system, grounding electrodes, frequency-dependent soils, full-wave electromagnetic modeling

Abstract

Lightning Protection System (LPS) must be properly designed to guarantee safe levels of transient voltages for people in the surrounding of the hit building and avoid damage to equipment. LPS comprises an upper grid, down conductors, and a grounding system (GS) in this context. The latter comprises an arrangement of vertical and horizontal electrodes whose precise representation must consider the frequency-dependent impedance and that these conductors are buried into a frequency-dependent soil. Additionally, the upper grid and down conductor can be represented by many transmission line models available. This paper investigates transient currents and voltages for an LPS subjected to lightning strikes, whose grounding system is buried in homogeneous frequency-constant (FC) and frequency-dependent (FD) soils. Results show that transient responses are considerably affected by the frequency dependence of the soil parameters, which are more pronounced in soils of high resistivity.