An Estimate of the Uncertainty in the Grounding Resistance of Electrodes Buried in Two-Layered Soils with Non-Flat Surface

Eduardo Faleiro,Gabriel Asensio,Jorge Moreno

doi:10.3390/en10020176

Eduardo Faleiro, Gabriel Asensio + Show 1 more

Open Access

https://doi.org/10.3390/en10020176

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Journal: Energies	Publication Date: Feb 4, 2017
Citations: 4	License type: CC BY 4.0

Affiliation: Universidad Politécnica de Madrid

Abstract

The influence of the irregular surface of a multi-layered soil on the estimation of the ground resistance of a complex electrode is studied. The electrode is placed in the first layer while the irregular surface is treated as the interface of an inhomogeneous volume filled with air and embedded in the first layer. A wide sample of irregular soils is generated and the variation of the electrode grounding resistance, as a function of a parameter that measures the surface unevenness, is evaluated. A stochastic model of the grounding resistance is proposed for which the variation of the electrode grounding resistance with its horizontal position relative to the surface is studied. The model features allow us to explain the variability found, as we are able to estimate the part of the uncertainty about the electrode grounding resistance measurements due to the non-planar soil surface.

Highlights

The grounding resistance is one of the most important parameters in the design of protection systems of electrical installations [1]
When irregularities occur on a small scale on the surface, i.e., at the electrode size scale, the grounding resistance measures may contain large errors which must be taken into account in the design stage of the protection system of the electrical installation
In a 3D domain, where σ ( r ) is the conductivity function and φ( r ) the potential that satisfies a set of boundary conditions which define univocally the configuration of the conductors, their electrical state and the properties of the inhomogeneous medium

Summary

Introduction

The grounding resistance is one of the most important parameters in the design of protection systems of electrical installations [1]. Variations in the content of water and mineral salts over time or the partial ionization of the terrain are some of them This is one of the main sources of uncertainty in the calculation of grounding resistance. When irregularities occur on a small scale on the surface, i.e., at the electrode size scale, the grounding resistance measures may contain large errors which must be taken into account in the design stage of the protection system of the electrical installation.

Remodeling the Layers

Background

Electrode

Findings

Conclusions