An innovative analysis of earthing grids for power substations

An innovative method for the determination of the earthing resistance and the touch potential of an earth grid for power substations has been developed in the paper. In the new scheme, each conductor of a given earthing grid is treated as a lossy transmission line. Input resistances of representative earthing grids have been evaluated, and good agreement between the data determined by the new method and the latest results published in literature has been observed. By plotting the potential variation on the earth surface three-dimensionally, the potential dips at the centre of each conductor mesh can be depicted, and with which the touch potential of the entire grid can then be enumerated.