On the Use of Electromagnetic Models and the 3D-FDTD Method in the Evaluation of Radiations Due to Lightning Strikes to Tall Objects

Abstract

The purpose of this paper is the investigation of the use of a lightning return stroke current electromagnetic model and the Finite Difference Time Domain (FDTD) method, in three dimensions, in order to study the Lightning Electromagnetic Pulse (LEMP) due to lightning strikes to tall objects (towers). The proposed approach and the developed code are validated by the comparison with the measured data taken obtained in the specialized literature. The evaluation of the LEMP propagation, in presence of different values of ground conductivity, is finally presented and discussed. It is found out that the use of electromagnetic models, which are close to the physical reality of the lightning phenomena, yields reasonably accurate results. The obtained simulation results, using a calculation code developed on Matlab, have turned out to be in very good agreement with measurement data. It has been found out also that the spatiotemporal current distribution along the tower and the lightning channel is influenced by the conductivity variation. Indeed, the LEMP propagation is significantly affected by both lightning current change and ground conductivity variation. It can be noted that the simulation results obtained can be exploited in order to study the coupling problems between LEMP due to lightning strikes to tall objects with different electrical, electronic and telecommunication systems.