Integrated Simulation of Electrochemical Corrosion for Dynamic Assessment of Substation Grounding System Condition

Electrochemical corrosion is one of the main causes of degradation of substation grounding devices and directly impacts the operational reliability of electric power facilities. Despite numerous studies on individual corrosion factors, comprehensive models considering the combined effects of soil physical and chemical properties and electrical operating conditions remain limited. This study analyzes emergency situations associated with grounding system failures and examines the effect of the main factors of electrochemical corrosion, including chloride ion concentration, soil moisture, environmental acidity, seasonal temperature changes, and leakage currents. Based on Faraday’s law, a mathematical model of electrochemical corrosion rate is proposed that combines the influence of the factors considered through correction factors. For practical implementation, an algorithm for the dynamic assessment of degradation of grounding system elements has been developed. The proposed model predicts changes in the cross-sectional area of grounding device elements, changes in grounding resistance, and the occurrence of potentially hazardous operating conditions. The developed algorithm assesses the risk of exceeding the permissible grounding potential, violating thermal withstand, the occurrence of hazardous step voltages, insulating breakdown, and disrupting the selectivity of relay protection devices.