ABSTRACT
Ground-fault currents flowing from a substation ground-grid into the soil may also circulate through buried conductive parts, which may be present in the earth (e.g., pipes, rails entering the substation, neighboring ground-grids, etc.). As a result, these passive elements might become energized, and the risk of electric shock due to dangerous touch voltages may be present, if such parts are accessible. In addition, these elements may transfer the ground-potential from the substation, where the fault occurs, to areas away from the substation. Buried conductive parts can increase the fault current density at the segments of the ground-grid closer to their location; this may change the surface potential profile around such buried conductive parts. The analytical methodology can be applied to study the interferences between an active ground-grid, which is leaking fault current into the earth, and a buried passive conductive part in its vicinity, which may be seen as the “victim” of the effects imposed upon it by the leaking ground-grid.
