Substation grounding grid resistance measurement using auxiliary circuits vertically disposed on the ground

An innovative methodology is proposed for measuring the resistance of substation grounding grids located in congested areas, particularly those in urban regions. The significant innovation is the use of auxiliary current and potential circuits vertically arranged on the ground. The feasibility of using the Fall of Potential (FoP) Method is experimentally investigated using the reduced model technique and an appropriate measuring electrode setup is proposed. The possibility of measurement using the two auxiliary electrodes, positioned in relation to the grid under test, obeying a ratio of 76%, is also evaluated. The depth of these measuring auxiliary electrodes for reliable measurements was determined from a theoretical study, a series of computer simulations, an experimental study in a reduced model, as well as measurements on a 100 m 2 grounding grid. The results show the feasibility of using the FoP Methodology as well as the two auxiliary electrodes whose distances to the grid obey the proportion of 76%.