Papers by Abdenbi Mimouni
Mathematical Modelling of Engineering Problems, 2020
The aim of this work is to evaluate the electric fields generated by vertical grounding electrode... more The aim of this work is to evaluate the electric fields generated by vertical grounding electrode in horizontally stratified soil during the passage of the lightning current through the grounding rod. The computation of the electric fields is performed using the Finite-Difference Time-Domain method in three dimensions (FDTD-3D). The observation points are located under and above ground. The effect of multi-layers soil on the transient behavior of the vertical grounding electrode and the associated electric field is illustrated and discussed. The obtained results were firstly compared and validated with other ones published in the literature for the case of homogeneous ground. The used method calculates easily the transients of grounding rod; it gives certain flexibility when taking into account the stratification of the soil and gives a better visualization of the electromagnetic field radiation. The found results can be easily used for the electromagnetic coupling problems.
IEEE Transactions on Electromagnetic Compatibility, 2019
In this paper, we present an analysis of electromagnetic fields generated by a lightning return s... more In this paper, we present an analysis of electromagnetic fields generated by a lightning return stroke to a tall tower in presence of a horizontally stratified two-layer ground. The electromagnetic fields are evaluated at a distance of 50 m from the tower for two observation points above and below the ground surface, by using the finite-difference time-domain method. The developed numerical model is validated using available experimental data obtained at the CN Tower in Toronto. To illustrate and discuss the effect of the soil stratification on the electromagnetic fields, we adopt two different cases characterized, respectively, by an upper layer less conductive than the lower level, and vice versa. The obtained results show, for the considered distance range (50 m), that the electromagnetic fields above ground at such close distance are nearly insensitive to the ground stratification. However, the underground electromagnetic fields are markedly affected by the properties of the soil layers. In the presence of a lower layer of higher conductivity, the horizontal electric field is characterized by a faster rise time, a significant decrease in amplitude and a bipolar wave-shape compared to that in the case of a homogeneous ground with the upper-layer characteristics. On the other hand, the presence of a lower layer with lower conductivity results in an increase of the peak value of the underground horizontal electric field.
Mathematical Modelling of Engineering Problems
The aim of this paper is to perform a parametric study in order to analyze factors having an effe... more The aim of this paper is to perform a parametric study in order to analyze factors having an effect on the vertical lightning field polarization to the CN-Tower in Canada, and estimate with numerical simulation, the horizontal distance for which the reversed polarity will occur. The calculation is performed using the Finite-Difference-Time-Domain technique in two dimensions (2D-FDTD), the spatial-temporal current propagation through the lightning channel and through the high structure is represented by the lumped-series voltage-source model. The obtained results show that the vertical electric lightning field behavior has a dual polarity, the transition from a negative waveform to a positive one is observed at different observation points localized near the elevated object influencing by each modification made to the tower-parameters, the medium conductivity and the return stroke speed value. These results can contribute to the understanding of the lightning-phenomenon and allow to ...
IEEE Transactions on Electromagnetic Compatibility
2010 30th International Conference on Lightning Protection (ICLP), 2010
In this paper we present a calculation method for distant horizontal electric fields radiated by ... more In this paper we present a calculation method for distant horizontal electric fields radiated by lightning return strokes over a two-layer horizontally stratified ground. A simplified expression is derived for the horizontal electric field combining the two-layer ground surface impedance and the Cooray-Rubinstein (CR) formula. The accuracy of the proposed formula to reproduce distant horizontal electric fields over a stratified ground is tested using finite-difference time-domain (FDTD) full-wave simulations. It is shown that the proposed formula is able to reproduce satisfactorily the horizontal electric field, particularly its early-time response.
The evaluation of induced overvoltages from indirect lightning has been for more years one of the... more The evaluation of induced overvoltages from indirect lightning has been for more years one of the most important problems in designing and coordinating the protection of overhead power lines. In this paper, we present the frequently coupling model used in the power lightning literature for the calculation of lightning induced overvoltages, the Agrawal approach. The algorithm applies to single conductor line above a perfectly conducting ground. The computation results are first validated by experimental results obtained using a reduced scale line model illuminated by the EMP simulator of the Swiss Federal Institute of Technology in Lausanne (SEMIRAMIS), and then are compared with the computation results obtained by the LIOV code (beta version).
Cited By (since 1996):4, Export Date: 1 December 2013, Source: Scopus
In this paper, our purpose is to compute radiated lightning electromagnetic fields using the hybr... more In this paper, our purpose is to compute radiated lightning electromagnetic fields using the hybrid method principle. The proposed method called the quasi-FDTD method is a new version of the classical hybrid method which is based partially on the use of the finite difference method in time domain (FDTD) for the calculation of the electric field components after the evaluation of the magnetic flux density using the images theory. However, the particularity of the proposed method is to take into account the finite conductivity of the ground in the lightning electromagnetic field calculations. This is obtained by a modification brought to the formulation of the classical hybrid method presented by Sartori and al in [2]. Furthermore, in the proposed method, the representation of the lightning current distribution is achieved by the use of engineering models typically the MTLE and MTLD models since they have showed reasonable agreement with measurements. Finally the simulation results ar...
IEEE Transactions on Electromagnetic Compatibility, 2014
2007 IEEE Lausanne Power Tech, 2007
Radio Science, 2011
In this paper we review simplified analytical expressions derived by Wait using the concept of at... more In this paper we review simplified analytical expressions derived by Wait using the concept of attenuation function for the analysis of the propagation of lightning‐radiated electromagnetic fields over a mixed propagation path (vertically stratified ground). Two different formulations proposed by Wait that depend on the relative values of ground surface impedances are discussed. It is shown that both formulations give nearly the same results for the time domain electric field. However, depending on the values of the normalized surface impedance for each ground section, the use of one of the two formulations is computationally more efficient. The accuracy of the Wait formulations was examined taking as reference full‐wave simulations obtained using the finite difference time domain technique. It is shown that Wait's simplified formulas are able to reproduce the distant field peak and waveshape with a good accuracy.
Journal of Electrostatics, 2008
We present an analysis of the electromagnetic fields at very close range from a tower struck by l... more We present an analysis of the electromagnetic fields at very close range from a tower struck by lightning. The electromagnetic fields are evaluated for observation points above, on the surface and below the ground plane characterized by a finite conductivity. The computations are obtained using the Finite-Difference Time-Domain (FDTD) technique, in which the so-called engineering models are incorporated to represent the spatial-temporal distribution of the current along the channel and along the strike object. The approach is tested using a set of simultaneously recorded data published in the literature consisting of the current measured at the top of the Peissenberg tower and the associated electric and magnetic fields and very good agreement has been found. Simulation results are performed for an observation point located 50 m from the base of the channel (or tower, when present) and for three cases, namely (i) a lightning strike to ground, and (ii) a lightning strike to a 168-m tall tower, and (iii) a lightning strike to a 553-m tall tower. The effect of the presence of the tower and the effect of finite ground conductivity on the generated above-ground and underground electromagnetic fields are illustrated and discussed. It is shown that the underground electric fields are markedly affected by the ground conductivity. The underground electric field is predominantly horizontal with a negative polarity. The vertical electric field component is characterized by a bipolar wave-shape. The ground conductivity affects in a lesser degree the magnetic field penetrating into the ground. Above the ground and on the ground surface, the vertical electric field and the azimuthal magnetic field generated by a lightning return stroke initiated at ground level are nearly insensitive to the height of the observation point above ground. For the considered distance range (50 m), they can be computed assuming the ground as a perfectly conducting plane. The magnetic field above ground at such close distance is virtually not affected by the ground conductivity. The presence of a tower results in a significant decrease of the vertical electric field in the immediate vicinity of the tower. Unlike the case of a ground-initiated return stroke, the above-ground vertical electric field associated with a return stroke to tall tower is very much affected by the ground conductivity. Depending on the value of this latter, this component could exhibit an inversion of polarity.
Journal of Applied Sciences, 2006
IEEE Transactions on Electromagnetic Compatibility, 2014
IEEE Transactions on Electromagnetic Compatibility, 2010
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Papers by Abdenbi Mimouni