The Sinusoidal Ground Electrode: Theory and Case Study Results.

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. [ABSTRACT FROM AUTHOR]