Lightning Surge Characteristics Analysis of Electrical Distribution Poles using the Method of Moments

Although various models of electrical distribution poles (EDPs) have been proposed for the investigation of lightning surge characteristics, it is still difficult to realize an accurate analysis. In this research, surge characteristics of EDPs are investigated using the method of moments. The models of a metallic pole, two models of a concrete pole with reinforcing steel rods, and a wooden pole are established from construction information. The lightning strikes are simulated as a vertical lightning channel 27m in length and an impulse generator is employed as the lightning strike. A grounding wire is connected along the surface of the poles to detect the lightning surge impedance change. The step responses of the voltage and current on each pole, with and without a connecting ground wire, are described. The simulation results show that surge impedance on the wooden pole with a connecting grounding wire is lower than the case without a grounding wire. In contrast, the grounding wire has only a slight effect on the surge impedance of the concrete poles and has no effect for the metallic poles.