The Sinusoidal Ground Electrode: Theory and Case Study Results
Keywords:
Electrical power distribution, ground electrodes, layered soil, matrix methodAbstract
This paper presents the analytical analysis of the sinusoidal ground electrode commonly used in Portugal by the Portuguese Electric Company. This electrode is easy to install, particularly for two layer soils with rocky bottom layer, and costs much less than it does a strip conductor. Both the theoretical results as well as measurements in the field have shown that the empirical model used by the company leads to large errors. Here the authors propose a new procedure to calculate the grounding resistance for this type of electrode using the average resistance between the wire and strip electrodes, which the calculation is well-established. To avoid heavy computation, the authors also propose the use of simple formulas in order to easily compute the strip resistance. The theoretical results and field measurements are compared and show the validity of the procedure being proposed here.
Downloads
References
M. M. Salama, M. M. Elsherbiny, and Y. L. Chow, “Calculation and interpretation of a grounding grid in two-layer earth with the synthetic-asymptote approach,” Electrc. Pow. Syst. Res., vol. 35, no. 3, pp. 157-165, Dec. 1995.
S. Berberovic, Z. Haznadar, and Z. Stih, “Method of moments in analysis of grounding systems,” Eng. Anal. Bound. Elem., vol. 27, no. 4, pp. 351- 360, Apr. 2003.
D. Sharma and S. De Four, “Parametric analysis of grounding systems in two-layer earth using Galerkin’s moment method,” IEEE PES T&D Conference & Exposition, Dallas, TX, pp. 541-547, May 21-24, 2006.
I. Colominas, J. Gomez-Calvino, F. Navarrina, and M. Casteleiro, “A general numeric model for grounding analysis in layered soils,” Adv. Eng. Softw., vol. 33, no. 7, pp. 641-649360, Jul. 2002.
I. Colominas, F. Navarrina, and M. Casteleiro, “A numerical formulation for grounding analysis in stratified soils,” IEEE Trans. Power Deliver., vol. 17, no. 2, pp. 587-595, Apr. 2002.
I. Colominas, J. Aneiros, F. Navarrina, and M. Casteleiro, “A BEM formulation for computational design of grounding systems in stratified soils,” The IV World Conf. on Comp. Mechanics, Buenos Aires, Argentina, 1998.
U. Adriano, O. Bottauscio, and M. Zucca, “Boundary element approach for the analysis and design of grounding systems in presence of nonhomogeneousness,” IEE Gener. Transm. Distrb. Proc., vol. 150, no. 3, pp. 360-366, May 2003.
L. M. Coa, “Comparative study between IEEE Std. 80-2000 and finite elements method application for grounding system analysis,” IEEE PES T&D Conference & Exposition, Caracas, Venezuela, pp. 1-5, Aug. 15-18, 2006.
J. Ma, F. P. Dawalibi, and R. D. Southey, “On the equivalence of uniform and two-layer soils to multilayer soils in the analysis of grounding systems,” IEE Gener. Transm. Distrb. Proc., vol. 143, no. 1, pp. 49-55, Jan. 1996.
Y. Liu, N. Theethayi, R. Thottappillil, R. M. Gonzalez, and M. Zitnik, “An improved model for soil ionization around grounding systems and its application to stratified soil,” J. Electrostat., vol. 60, no. 2-4, pp. 203-209, Mar. 2004.
E. Mombello, O. Trad, J. Rivera, and A. Andreoni, “Two-layer soil model for power station grounding system calculation considering multilayer soil stratification,” Electr. Pow. Syst. Res., vol. 37, no. 1, pp. 67-78, Apr. 1996.
Y. Than, F. R. Pazheri, N. H. Malik, A. A. AlArainy, and M. I. Qureshi, “Novel approach of estimating grounding rod optimum dimensions in high resistivity soils,” Electr. Pow. Syst. Res., vol. 92, pp. 145-154, 2012.
http://www.edpdistribuicao.pt/pt/profissionais/Lis ts/EDPDocumentosNormativos/Attachments/353/ DRE-C11-040N.pdf.
R. Meliopoulos, Power System Grounding and Transients, Marcel Dekker, Inc., New York, 1988.
IEEE, Grounding of Industrial and Commercial Power Systems, IEEE Std. 142-2007, 2007.
G. F. Tagg, Earth Resistances, George Newnes Limited, London, 1964.
E. B. Joy, A. P. Meliopoulos, and R. P. Webb, “Touch and step calculations for substation grounding systems,” IEEE Trans. Power Ap. Syst., vol. PAS-98, no. 4, pp. 1143, July/Aug. 1979.
