FINITE ELEMENT-BASED OPTIMIZATION OF THE LIGHTNING CONDUCTION STRUCTURE IN REINFORCED POLES FOR MEDIUM VOLTAGE DISTRIBUTION LINES

Abstract

Lightning-induced overvoltages pose a significant threat to the reliability of medium voltage (MV) distribution lines in power system, particularly through their impact on line insulators. Among the key parameters influencing these overvoltages is the surge impedance of pole structures, especially reinforced concrete poles commonly used in MV networks. Traditional analytical methods for surge impedance calculation are limited to simple pole geometries and do not adequately address configurations that include external grounding wires. This paper proposes a finite element method (FEM)-based approach to accurately compute the surge impedance of more complex pole structures incorporating external grounding conductors. The proposed method enables the detailed modeling of electromagnetic interactions within the pole-ground system and facilitates the optimization of grounding designs. Simulation results demonstrate that the optimized grounding structure significantly improves lightning discharge performance, offering a practical implementation to enhance the resilience of MV distribution systems against lightning-induced transients.