DETERMINATION OF THE MUTUAL GROUND RESISTANCE OF ADJACENT GROUNDING GRIDS

Abstract

The article discusses the determination of the mutual ground resistance of two adjacent metallically connected grounding grids. For this purpose, an original analytical expression for calculating the corresponding mutual ground resistance of two adjacent grounding grids has been developed. There is a complex electromagnetic coupling between adjacent grounding grids. The conductive component of this coupling is particularly evident. During a ground fault, this component markedly increases the ground resistance of the corresponding grounding system. It is essential to establish the aforementioned mutual ground resistance correctly in order to determine the distribution of the partial ground fault currents in a system of adjacent grounding grids. The determination of mutual ground resistance is presented using two specifi c grounding grids buried in poorly conductive soil.