Responses of Airport Runway Lighting System to Direct Lightning Strikes: Comparisons of TLM Predictions With Experimental Data

A test airport runway lighting system, including a buried cable protected by a counterpoise and vertical ground rods, was subjected to direct lightning strikes, and currents and voltages measured in different parts of the system were reported earlier by Bejleri et al. In this paper, we attempt to model the lightning interaction with this system using the transmission line theory. Lumped devices along the cable such as current regulator and transformers are ignored; possible nonlinear phenomena (arcing) in the system are neglected; the soil is assumed to be homogeneous. The model-predicted currents in the counterpoise, ground rod, and the cable are compared with the measurements, and a reasonable agreement was found for the currents along the counterpoise. It is found that current in the counterpoise is not much influenced by the presence of the cable. Further, vertical ground rods connected to the counterpoise do not have significant influence on the current distribution along the counterpoise. It appears that the model is unable to predict cable currents and voltages in the test system, presumably due to neglecting nonlinear phenomena in the soil and in cable´s insulation and electromagnetic coupling with the lightning channel.