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

Abstract

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 paper aims 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 are compared with the measurement data and those obtained using the engineering models. Findings The proposed modeling technique has proved to be more accurate than the conventional methods, particularly in the prediction of current distribution along the tall tower and the vertical component of the radiated electric field. Originality/value The main feature of the proposed technique is its ability to consider the impact of metallic structures in a large space around lightning channel on the predicted radiated electromagnetic fields, having no concern on computer memory requirements.

Measurement and approximation by simulation of the instantaneous breakdown voltage of lightning discharge in the presence of protection

“…Protection against lightning has always been a subject of researches because of several damages caused by this phenomenon (Hajebi et al , 2016; Piantini and Janiszewski, 1994; Rakov et al , 2003; Zou et al , 2013). To ensure optimal protection, the electrogeometrical model was developed and adopted for the dimensioning of the protection (Cooray and Becerra, 2010; Haddad and Warne, 2007; Kuffel et al , 2000).…”

Modeling of artificially triggered lightning currents by multi-peaked analytically extended functions

“…Lightning currents are measured not only at the tall instrumented towers during natural lightning discharges but also in artificially triggered lightning experiments (Leteinturier et al, 1990, Uman et al, 2002, Rakov, 2001, 2010, Hajebi et al, 2016. Waveshapes of the currents in lightning discharges to specific low objects and installations of interest, trees, ground or water surfaces, cannot be measured because of the low probability of striking to a certain point.…”