Factors Affecting the Position of Interception of an Electrical Discharge from a Rod to the Ground in a Gap Containing Grounded Conductors at a Short Distanse Over the Ground Level

In this paper, the results of the laboratory investigations concerning the probability of intercepting a lightning discharge by grounded metallic objects laying close to the surface of the soil are presented. The main parameters which have been investigated in the high voltage laboratory are the soil resistivity and the distances from the ground, as well as between the two grounded parallel conductors introduced in a short rod-plane gap and stressed by positive impulse voltages 2/40 μs. Under certain presuppositions the results of this investigation can be extrapolated for estimating the probability of a lightning discharge to strike a landed, parked aircraft in an airport. The results have proved an influence of the soil resistivity as well as of the distance between the two grounded conductors on the relative probability of a breakdown to be intercepted by these conductors.