Lightning surge response of ground electrodes

Lightning surge currents cause nonlinear ionization and transient propagation when injected into ground electrodes. The low-current footing resistance is modeled in terms of electrode length and surface area. The ionization process follows a similarity method originated by A.V. Korsuncev (1958). Calculation and experiment show the surge response of a conducting ground plane. Electrode shape, soil type, ionization and propagation are then combined to provide a comprehensive model of tower footings for use in predicting the lightning outage rates of overhead transmission lines. The model is compared with previous experimental and analytical work and is shown to provide a reasonable match