Current and radiated electromagnetic fields due to lightning return strokes when hitting elevated objects

Purpose – Tall towers have a high potential for being struck by lightning which is a major source of electromagnetic radiation with adverse effects on electric, electronic and telecommunication instruments. The purpose of this paper is to present an accurate method for predicting the radiated electromagnetic fields and current distribution along the lightning channel and the tower hit by the lightning. Design/methodology/approach – The electromagnetic model is utilized to model the lightning channel and the tower is represented by lossy conducting wires. The finite-difference time-domain (FDTD) method is used to solve for the governing Maxwell’s equations. Due to the large computational space, the FDTD code is paralleled between several computer processors. To enhance the efficiency of the code, a non-uniform mesh is used, reducing the mesh length in the air-ground interface. For model evaluation, simulated current distribution along the lightning channel and tower, and the radiated electromagnetic fields...