Search results for "earth electrodes"
showing 3 items of 3 documents
Soil ionization of earth electrodes under high pulse transient currents
2007
This paper proposes a numerical model of soil ionization phenomena that can occur when earth electrodes are injected by high pulse transient currents. The model is solved by a finite difference time domain numerical scheme. It has been developed from a thorough analysis of the available studies in technical literature about the peculiar physical dynamics of soil ionization phenomena. As already underlined, soil ionization can occur, for example, when the earth electrode has to drain a lightning current into the soil. In this case, the electric field can overcome the electrical strength and conductive plasma paths can locally grow. The dimension of these ionized air channels are strictly dep…
Results of the research on global earthing systems: A contribution to the problem of their identification
2013
The paper presents a study on the factors that can have influence on the rise of a Global Earthing System. The first part of the work deals with: - the definition of proximity, interconnection and quasi-equipotential; - the influence of the presence of HV/MV stations on the dangerous voltages and on the permissible voltage limits; - the dependence of the hazardous condition for persons on the different kind of fault; - the effects on safety of the coexistence of HV, MV and LV systems. In the second part, starting from the discussion on the themes above-mentioned and on the results of the studies, measurement campaigns and simulations on interconnected earthing systems done in the last fifte…
Earthing System's Design in presence of non-uniform soil
2007
The Authors propose a practical approach for facing the problem of the design of the earthing systems in two-layer soils. The approach is based on the calculation of an equivalent resistivity of the non-uniform soil through which the designer can treat this one as it was uniform. The purpose of the Authors is to provide an innovative simple method and some easy-to-use graphs for an easy earthing systems’ design in two-layer soils.