Practical evaluation of ground enhancing compounds for high soil resistivities

In order to study the long-term effect of using “ground enhancing compounds” in conjunction with various ground electrodes, a common project between Electrical Research Institute (IIE) and the Mexican Electrical Utility (CFE), was started in 2007. The aim of the project is to characterize the ground enhancing compounds in order to obtain the relative benefit and take into account their limitations, to get the best results when applied in transmission lines. The project is divided into two main tasks: short-term measurements by laboratory studies and long-term measurements by field evaluation. In the lab, mechanical and electrical [1], corrosion and chemical measurements were performed, and in the field soil resistivity and ground resistances were measured [2]. This work shows the behavior of the ground resistance of ground electrodes made of ground enhancing compounds, and the results are compared with mathematical relationships available in the literature. Good agreement is observed for all compounds, mainly for up to 1500 Ωm, and the benefit will depend of the ground enhancing compound used and the soil resistivity.