An Investigation of Earth Grid Performance Using Graphene-Coated Copper

Large power systems are normally operated with their neutral points directly earthed. At a major generating or switching station, this results in the provision of a large earth grid buried in the ground. The design of earthing systems requires a worst case approach. There is a possibility of heavy currents flowing into the earth grid from the overhead earth wires through the tower during a line conductor fault and from lightning strikes. The flow of earth current during a fault or lightning conditions results in a rise of earth grid potential with respect to a physically remote earth point, which can lead to unsafe conditions under some conditions for personnel and connected electrical plant. This paper aims to investigate the potential of adding novel coatings to the conventional copper earth grid conductors to enhance overall conductivity and diminish corrosion. This contributes to lowering the rise of earth grid potential. Graphene-coated copper performance as an earth grid conductor is evaluated with staged low voltage fault and the corrosion behavior in both a destructive and nondestructive environment. A comparison of the simulation software packages CDEGS and CST is also carried out using lightning strike conditions.