Calculation of Electromagnetic Fields in the Vicinity of the Lightning Channel

2015 ◽  
Vol 51 (3) ◽  
pp. 1-4 ◽  
Author(s):  
Ping Wang ◽  
Lin Li
Keyword(s):  
Electromagnetic Fields ◽  
Lightning Channel

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

2016 ◽  
Vol 35 (3) ◽  
Author(s):  
Maryam Hajebi ◽  
Mojtaba Khosravi-Farsani ◽  
Seyed Hossein Hesamedin Sadeghi ◽  
Rouzbeh Mazandarani Moini
Keyword(s):  
Electromagnetic Fields ◽  
Current Distribution ◽  
Design Methodology ◽  
Fdtd Method ◽  
Measurement Data ◽  
Vertical Component ◽  
Uniform Mesh ◽  
Large Space ◽  
Lightning Channel ◽  
The Impact

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.

scholarly journals EVALUATION OF ELECTROMAGNETIC FIELDS DUE TO INCLINED LIGHTNING CHANNEL IN PRESENCE OF GROUND REFLECTION

2013 ◽  
Vol 135 ◽  
pp. 677-694 ◽  
Author(s):  
Mahdi Izadi ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Maryam Hajikhani
Keyword(s):  
Electromagnetic Fields ◽  
Lightning Channel

Analysis of Electromagnetic Fields Generated by Inclined Lightning Channel

2015 ◽  
Vol 40 (9) ◽  
pp. 2585-2608
Author(s):  
Said I. Abouzeid ◽  
G. Shabib ◽  
Adel Zein El Dein
Keyword(s):  
Electromagnetic Fields ◽  
Lightning Channel

scholarly journals On the Lightning Electromagnetic Fields due to Channel with Variable Return Stroke Velocity

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
M. Izadi ◽  
M. Z. A. Ab Kadir ◽  
M. Hajikhani
Keyword(s):  
Electromagnetic Fields ◽  
Time Domain ◽  
Calculation Methods ◽  
Return Stroke ◽  
Average Value ◽  
Lightning Current ◽  
Lightning Channel ◽  
The Time Domain ◽  
General Velocity ◽  
Good Agreement

Numerical field expressions are proposed to evaluate the electromagnetic fields due to the lightning channel with variable values of return stroke velocity. Previous calculation methods generally use an average value for the return stroke velocity along a lightning channel. The proposed method can support different velocity profiles along a lightning channel in addition to the widely used channel-base current functions and also the general form of the engineering current models directly in the time domain without the need to apply any extra conversions. Moreover, a sample of the measured lightning current is used to validate the proposed method while the velocity profile is simulated by the general velocity function. The simulated fields based on constant and variable values of velocity are compared to the corresponding measured fields. The results show that the simulated fields based on the proposed method are in good agreement with the corresponding measured fields.

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

2018 ◽  
Vol 37 (4) ◽  
pp. 1354-1365
Author(s):  
Vesna Javor ◽  
Karl Lundengård ◽  
Milica Rančić ◽  
Sergei Silvestrov
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Wire Antenna ◽  
Lightning Protection ◽  
Approximation Procedure ◽  
Content Type ◽  
Lightning Channel ◽  
Triggered Lightning ◽  
Lightning Discharges ◽  
Extended Function

Purpose This paper aims to present the approximation of lightning currents waveshapes by the multi-peaked analytically extended function (MP-AEF) for the experimentally measured channel-base currents in the artificially triggered lightning discharges. Modified transmission line model of lightning return strokes having the channel current both linearly decaying and sinusoidally changing with height (MTLSIN) is used to calculate the lightning electromagnetic field. Design/methodology/approach MP-AEF’s parameters for the artificially triggered lightning channel-base currents are calculated by using Marquardt least squares method (MLSM). Lightning electromagnetic fields are calculated based on electromagnetic theory relations, thin-wire antenna model of the vertical lightning channel and the assumption of the perfectly conducting ground. MTLSIN model as an engineering model of lightning strokes is used to obtain the electric field results as these are simultaneously measured in rocket-triggered lightning experiments together with the channel-base currents. Findings MP-AEF approximates multi-peaked pulse waveshapes. Some important function parameters are chosen prior to the approximation procedure, such as current peaks and the corresponding time moments of those peaks, which presents an advantage in comparison to other functions. The desired accuracy of approximation is obtained by choosing an adequate number of function terms. MLSM is used for the estimation of unknown parameters. Using MTLSIN model, the influence of the channel height and return stroke speed on the lightning electromagnetic field waveshape is analyzed in this paper. Research limitations/implications MP-AEF may be used for approximation of various multi-peaked waveshapes. It has no errors in the points of maxima which is important for the lightning protection systems design. MTLSIN model may be validated by using simultaneously measured lightning electromagnetic fields at various distances from the channel and for channel heights estimated in the experiments. It is also possible to approximate measured current derivatives by MP-AEF and use them for further computation. Originality/value MTLSIN model is proposed in this paper for the evaluation of lightning electromagnetic fields induced by artificially triggered lightning discharges. The procedure is based on the approximation of lightning channel-base currents by the multi-peaked analytically extended function previously proposed by the authors. This function may be used not only for representing lightning currents but also for other waveshapes as current derivatives, electric and magnetic fields and their derivatives, which are all important for the lightning protection design. MTLSIN gives lightning electromagnetic fields results which are in better agreement with measured fields than those obtained by other models from literature.

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