A fast method to compute the grounding resistance of a coated electrode using the coated electrode equivalent radius

• Published in: International journal of electrical power & energy systems Vol. 137; p. 107879
• Main Authors: Faleiro, E., Asensio, G., Denche, G., Moreno, J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2022
• Subjects: Coated electrode equivalent radius; Conductive material layer; Grounding resistance; Oxide layer; Coated electrode equivalent radius; Conductive material layer; Grounding resistance; Oxide layer
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2021.107879

•A fast calculation of electrical parameters of coated grounding electrodes.•Simulating the effect of oxidation by modifying the electrode radius.•Introducing the Coated Electrode Equivalent Radius by simple expression.•Conventional calculation methods are used by modifying the radius of the coated electrodes. The effect of an oxide layer or any conductive material layer surrounding the electrode surface on the performance of grounding system is studied in this paper. The boundary elements method applied to the electrode surface together with the Equivalent Surface Charge Distribution model to assess the contribution of the material-soil interface are used to compute the grounding resistance of an electrode buried in a semi-infinite soil and energized by a low frequency current. Due to the high computation time required to apply the numerical method to find the solution of the problem, the Coated Electrode Equivalent Radius is introduced from the study of the grounding resistance as a tool to simulate the effect of the material layer on the electrode. This equivalent radius is a function of the thickness of the material layer and can be used in common methods for calculating parameters of a grounding system such as grounding resistance and step and touch potentials. The proposed expression for the equivalent radius is tested in several synthetic examples and also in a real case. Some of the tests carried out are also compared with the results of using commercial software.