Lightning Surge Analysis Model of Reinforced Concret Pole and Grounding Lead Conductor in Distribution Line

Abstract

AbstractThe grounding resistance is one of the most important factors to determine lightning overvoltages on a distribution line. A reinforced concrete pole should be treated as a kind of a grounding lead conductor and a grounding electrode for lightning overvoltages. The grounding lead conductors for surge arresters, shielding wires, and transformers in Japanese distribution lines are laid along the reinforced concrete pole. The grounding resistance in the distribution lines becomes low due to breakdown between the concrete pole and the lead conductors caused by the lightning overvoltages. Soil ionization due to high current reduces the grounding resistance. Thus, lightning currents make the grounding resistance low. This paper proposes a lightning surge analysis model of the grounding system. The proposed model represents surge characteristics of the reinforced concrete pole and the grounding lead conductor, and current dependence of the grounding resistances due to the soil ionization. Simulation results using the proposed model suggest the importance of the surge characteristics of the reinforced concrete pole. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.