Executive Summary : | The importance of a reliable earthing scheme in modern power systems is growing due to the increasing penetration of renewables and the need to efficiently dissipate a spectrum of frequencies in the current. The electrical parameters of the soil, the geometry of the grounding electrode system, and the interface between the electrode and the soil govern earthing efficiency. Corrosion in ground electrodes can significantly affect their performance, especially during lightning faults, where the magnitude of current flow can initiate soil ionization/breakdown. Isolated grounding electrode schemes, mostly made of steel, need to be quantified in different climatic conditions and soil types. Zinc coating is provided to avoid corrosion, but long-term performance remains unclear. Studies on the effect of acid rain and pollutants on soil electrical properties and grounding performance are needed. The physical characteristics of soil ionization and breakdown phenomenon under non-standard impulse voltage/current, including oscillatory impulse voltage/currents, are also important. The study aims to contribute to understanding the impact of water and acid rain on different soils, lime stabilization on expansive soil for grounding, and corrosion behavior of various electrodes under different soil conditions. Physico-chemical diagnostic studies are needed to gain important properties of soil subjected to multiple discharges, and a corrosion-resistant grounding electrode material for higher efficiency and reliable grounding. |