A Novel Method to Determine Earth Fault Split Factor For Grounding Grid Design of HV Substations

To design a safe substation grounding grid, it is necessary to compute the split factor for earth fault current, and also current distribution in other possible paths. In this paper, a novel, simple and accurate method is developed for the determination of split factor. In the proposed algorithm grounding grid impedance of adjacent substations, nonsimilar tower footing resistances and parallel circuits, more than one earth wires and different spans in transmission lines can be considered. Finally, the results are compared with the others which show good agreement and accuracy.