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The soil characterization is one of the major prerequisites in grounding system studies. Along with an adequate measurement procedure and a reliable field data processing, they are responsible for the success in the design and the installation of grounding grids in electrical power systems. In this frame of reference, the purpose of this work is to present an embracing investigation combining in-situ measuring data from soil resistivity and geological survey, supported by the Wenner method and standard penetration test (SPT). The study is focused on investigating the differences in the apparent soil resistivity interpretation, provided by distinct approaches, identifying the one that better correlates with SPT. Furthermore, a geoelectrical and geotechnical soil characterization is in-depth evaluated, culminating in the derivations among soil resistivity, moisture content, and its mechanical properties. The study has a particular application, but not restricted, to electrical substations design, in which a proper soil modeling and representation are mandatory. The obtained results are promising serving as a foundation for further investigation. [ABSTRACT FROM AUTHOR]

This article presents a methodology to calculate grounding potentials in adjacent electrodes present in high-voltage substations subjected to a short-circuit current dissipated in the main grid. The contribution of the technique is the consideration of the coupling by the soil among electrodes taking into account a two-layer soil and irregular geometry of the conductors. This problem is of special concern due to the presence of passers-by near metallic fences, not directly connected to the grounding grid, whose potentials usually have not been evaluated. In this context, the article presents a general analytical formulation aiming to estimate the potential in multiple electrodes, leading to a possible risk to human beings close to the substation. Sensitivity studies are performed in order to evaluate the effect of the soil resistivity and the distance from the faulted grid and the coupled electrode. A practical application in a substation grounding system is discussed. Finally, a huge grounding system is evaluated in order to verify the robustness of the proposed formulation. [ABSTRACT FROM AUTHOR]