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Article
Publication date: 1 January 2014

Sanmugasundaram Thirukumaran, Paul Ratnamahilan Polycarp Hoole, Harikrishnan Ramiah, Jeevan Kanesan, Kandasamy Pirapaharan and Samuel Ratnajeevan Herbert Hoole

As commercial and military aircraft continue to be subject to direct lightning flashes, there is a great need to characterize correctly the electrical currents and electric…

Abstract

Purpose

As commercial and military aircraft continue to be subject to direct lightning flashes, there is a great need to characterize correctly the electrical currents and electric potential fluctuations on an aircraft to determine alternative design approaches to minimizing the severity of the lightning-aircraft dynamics. Moreover, with the increased severity of thunderstorms due to global warming, the need arises even more to predict and quantify electrical characteristics of the lightning-aircraft electrodynamics, which is normally not measurable, using a reliable electric model of the aircraft. Such a model is advanced here. The paper aims to discuss these issues.

Design/methodology/approach

The case considered in this paper is that of an aircraft directly attached to an earth flash lightning channel. The paper develops a new approach to modelling the aircraft using electric dipoles. The model has the power to represent sharp edges such as wings, tail ends and radome for any aircraft with different dimensions by using a number of different sized dipoles. The distributed transmission line model (TLM) of the lightning return stroke incorporating the distributed aircraft model is used to determine aircraft electrical elements and finally the electric current induced on the aircraft body due to lightning's interaction with the aircraft. The model is validated by the waveform method and experimental results.

Findings

The dipole model proposed is a very powerful tool for minute representation of the different shapes of aircraft frame and to determine the best geometrical shape and fuselage material to reduce electric stress. This charge simulation method costs less computer storage and faster computing time.

Originality/value

The paper for the first time presents a computer-based simulation tool that allows scientists and engineers to study the dynamics of voltage and current along the aircraft surface when the aircraft is attached to a cloud to ground lightning channel.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33 no. 1/2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 October 1997

John Hardwick

Lightning strikes are potentially dangerous so aircraft manufacturers work hard to design effective protection. Explains how LTT’s expertise ensures that manufacturers’ protection…

423

Abstract

Lightning strikes are potentially dangerous so aircraft manufacturers work hard to design effective protection. Explains how LTT’s expertise ensures that manufacturers’ protection systems are reliable.

Details

Aircraft Engineering and Aerospace Technology, vol. 69 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 20 August 2018

Vesna Javor, Karl Lundengård, Milica Rančić and Sergei Silvestrov

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

Abstract

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.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 4 May 2012

Vesna Javor

The purpose of this paper is to present a new function for approximating lightning channel‐base currents which is useful in return stroke modelling and for calculating lightning

Abstract

Purpose

The purpose of this paper is to present a new function for approximating lightning channel‐base currents which is useful in return stroke modelling and for calculating lightning electromagnetic fields and induced effects in conductive structures, installations and systems.

Design/methodology/approach

The derivative and integral of the function are obtained analytically. Function parameters are calculated to approximate theoretically assumed or experimentally measured first stroke channel‐base currents using least‐squares method. The proposed expressions are useful for calculating lightning electromagnetic field using thin wire antenna approximation and lightning stroke models. Analytically obtained Fourier transform of the function is needed in the case of a lossy ground.

Findings

The function can approximate both double and one‐rise front waveshapes, so as faster and slower decaying tails. Some important function characteristics can be chosen prior to the approximation procedure, such as the current peak and rise‐time to peak, which is an advantage in comparison to other functions from literature. Parameters can be calculated so to obtain the desired decreasing‐time to half of the peak value; maximum current steepness due to analytically obtained derivative; charge transfer corresponding to the function integral; the specific energy corresponding to integral of the square of the function, etc.

Research limitations/implications

This function can be used also for approximation of other impulse quantities of interest.

Originality/value

The new proposed function for lightning current modelling is suitable for generalization of the procedure for computing electromagnetic fields and induced effects.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 3 May 2013

Jae‐bok Lee, Jun Zou, Mo Li and Sughun Chang

A fast algorithm is proposed to calculate the lightning electromagnetic field over a perfectly conducting earth surface.

Abstract

Purpose

A fast algorithm is proposed to calculate the lightning electromagnetic field over a perfectly conducting earth surface.

Design/methodology/approach

The channel base current is approximated by a number of sub‐domain quadratic functions using the proposed adaptive sampling technique, and the derivative and integral of the channel base current with respect to time can be analytically expressed. With the help of these approximations, the ideal electromagnetic field of the lightning channel can be evaluated along the lightning channel with respect to the height.

Findings

The computational time can be greatly reduced using the proposed approach to evaluate the electromagnetic field of a lightning channel in the time domain.

Originality/value

The adaptive sampling technique is a general‐purposed approach, which can be potentially used in other applications to fit a function with the minimal number of intervals.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 17 March 2016

Maryam Hajebi, Mojtaba Khosravi-Farsani, Seyed Hossein Hesamedin Sadeghi and Rouzbeh Mazandarani Moini

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…

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.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 35 no. 3
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 1 September 2001

Amedeo Andreotti, Federico Delfino, Paola Girdinio and Luigi Verolino

An identification procedure for lightning return strokes is proposed. It makes it possible to reconstruct the return stroke height‐dependent attenuation function making use only…

Abstract

An identification procedure for lightning return strokes is proposed. It makes it possible to reconstruct the return stroke height‐dependent attenuation function making use only of the measured vertical component of the electric field radiated by the lightning channel and it can be performed without any information about the channel base current, the measurement of which is generally very difficult and noisy. It is also shown that the method, with suitable modifications, can also be employed for the mathematical evaluation of the lightning channel height, which is a physical quantity a priori unknown. The approach has been validated by means of the numerical simulation of classical TL, MTLL and MTLE engineering models for a wide class of return strokes, with height ranging in the interval 15‐30km.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 20 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 11 November 2013

Jun Zou, Chenglong Zhou, Wenwen Li, Jae-bok Lee and Sughun Chang

The electromagnetic field radiated from a lightning channel is the excitation for analyzing the field-to-transmission line coupling problem. The purpose of this paper is to…

Abstract

Purpose

The electromagnetic field radiated from a lightning channel is the excitation for analyzing the field-to-transmission line coupling problem. The purpose of this paper is to propose a novel efficient approach to evaluate the horizontal electric field of the lightning channel expressed by the generalized Sommerfeld integral.

Design/methodology/approach

The asymptotic integral is extracted from the original one, which actually makes the Sommerfeld integral tail reach its convergence very quickly. To handle the sharp variance around k0, a closed-form integral, which is obtained by replacing the original kernel with an approximated function, is presented in detail. The numerical examples validated the proposed approach in the both frequency and time domain.

Findings

The approach proposed in this paper has been validated by the comparison with results in other papers. The agreement among these results reaches very well, and the approach proposed in this paper is more efficient and easy to implement, especially for the calculation of the tail integral part.

Originality/value

In accordance with the numerical experiments, the proposed approach can be served as a qualified candidate in terms of computational efficiency to evaluate the electromagnetic field generated by the lightning channel.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 32 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 13 July 2010

Nassima M'ziou, Leila Mokhnache, Ahmed Boubakeur, Zineddine Azzouz and Rafic Kattan

The purpose of this paper is to propose a numerical method in time domain in order to solve the electric and magnetic fields radiated from lightning in the presence of the tall…

Abstract

Purpose

The purpose of this paper is to propose a numerical method in time domain in order to solve the electric and magnetic fields radiated from lightning in the presence of the tall tower. This paper is very important in calculating lightning electromagnetic field – obtaining directly the solution in time domain with a reduced computation time and reduced space memory.

Design/methodology/approach

In this paper, a HYBRID method is proposed for the calculation of the electromagnetic field associated with lightning strikes to tall towers. The proposed method is a combination between a numerical integration method and the finite difference time domain (FDTD) method. The HYBRID method is an alternative approach that takes advantage of this combination to calculate, first, the radiated magnetic field; this field is obtained by the use of the Simpson method, and, second the electric field, based partially on the FDTD method.

Findings

The results of lightning electromagnetic field in the presence of a tall tower obtained by this proposed method: HYBRID method are in agreement with experimental results or simulated results (by the use of other methods: method in frequency domain). This method can be applied to solve the lightning electromagnetic field equation for far distances or close distances from lightning stroke.

Originality/value

This paper presents a temporal method to obtain the lightning electromagnetic field in the presence of a tall tower with reduced space memory and reduced time.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 8 May 2018

Mostafa Kheshti and Xiaoning Kang

Distribution network protection is a complicated problem and mal-operation of the protective relays due to false settings make the operation of the network unreliable. Besides…

Abstract

Purpose

Distribution network protection is a complicated problem and mal-operation of the protective relays due to false settings make the operation of the network unreliable. Besides, obtaining proper settings could be very complicated. This paper aims to discuss an innovative evolutionary Lightning Flash Algorithm (LFA) which is developed for solving the relay coordination problems in distribution networks. The proposed method is inspired from the movements of cloud to ground lightning strikes in a thunderstorm phenomenon. LFA is applied on three case study systems including ring, interconnected and radial distribution networks. The power flow analysis is performed in Digsilent Power Factory software; then the collected data are sent to MATLAB software for optimization process. The proposed algorithm provides optimum time multiplier setting and plug setting of all digital overcurrent relays in each system. The results are compared with other methods such as particle swarm optimization and genetic algorithm. The result comparisons demonstrate that the proposed LFA can successfully obtain proper relay settings in distribution networks with faster speed of convergence and lower total operation time of relays. Also, it shows the superiority and effectiveness of this method against other algorithms.

Design/methodology/approach

A novel LFA is designed based on the movements of cloud to ground lightning strikes in a thunderstorm. This method is used to optimally adjust the time multiplier setting and plug setting of the relays in distribution system to provide a proper coordination scheme.

Findings

The proposed algorithm was tested on three case study systems, and the results were compared with other methods. The results confirmed that the proposed method could optimally adjust the relay settings in the electric distribution system to provide a proper protection scheme.

Practical implications

The practical implications can be conducted on distribution networks. The studies provided in this paper approve the practical application of the proposed method in providing proper relay protection in real power system.

Originality/value

This paper proposes a new evolutionary method derived from the movements of cloud to ground lightning strikes in thunderstorm. The proposed method can be used as an optimization toolbox to solve complex optimization problems in practical engineering systems.

1 – 10 of 571