Charge and Current Simulation Method with Boundary Element Method for Grounding System Calculations in Case of MultiLayer Soil

Abstract

Grounding resistance is not only the measurable parameter to give an information about the performance of grounding grids due to discharging current into grounding grids Grounding grids but it is preferable to include the distribution of surface potential and, subsequently, the touch and step voltages over the area above the substation grounding grid and beyond. This paper focuses on the analytical methods to compute not only the Grounding resistance but also the earth surface potential. Three methods are used to compute (Rg) and (ESP). The first one is the charge simulation method , the second is current simulation method and the last one is the boundary element method (BEM). For BEM, commercial software TOTBEM by university of La Cournia, Spain is used for computing ESP and Rg. The owned Fortran code for the first and second method is developed to calculate the ESP and Rg. This study is taken into account the type of the soil. In case of grounding resistance, a comparison between the three methods results and IEEE Standard formula is presented. The results refers that the Fortran code is valid for ESP and Rg calculations.