DocumentCode :
71028
Title :
Evaluation of Lightning Electromagnetic Fields and Their Induced Voltages on Overhead Lines Considering the Frequency Dependence of Soil Electrical Parameters
Author :
Akbari, Mohammad ; Sheshyekani, K. ; Pirayesh, A. ; Rachidi, Farhad ; PAOLONE, MARIO ; Borghetti, Alberto ; Nucci, Carlo Alberto
Author_Institution :
Electr. & Comput. Eng. Dept., Shahid Beheshti Univ., Tehran, Iran
Volume :
55
Issue :
6
fYear :
2013
fDate :
Dec. 2013
Firstpage :
1210
Lastpage :
1219
Abstract :
This paper presents a comprehensive study on the effect of the frequency dependence of soil electrical parameters on the lightning radiated electromagnetic fields as well as their associated induced voltages on overhead lines. To this aim, a full-wave approach based upon the finite-element method (FEM) is utilized. In the analyses, frequency dependence of soil conductivity and relative permittivity is introduced, using available analytical formulae that is obtained from experimental data. It is shown that the radial electric field is the only component which is significantly affected by the frequency dependence of soil electrical parameters at observation points as close as some tens of meters from the lightning channel. The vertical component of the electric field and the azimuthal component of the magnetic field are not much influenced by this property of soil at moderate distances (up to several hundred meters) from the lightning channel. For distant observation points and for poorly conducting grounds, however, these components are also affected. It is also shown that for soils characterized by relatively moderate and low resistivity values (less than 1000 Ω.m), lightning-induced voltages are not significantly affected by the frequency dependence of soil electrical parameters. For poorly conducting soils, instead, the frequency dependence of soil electrical parameters results in a decrease of lightning-induced voltages.
Keywords :
electromagnetic fields; finite element analysis; lightning; permittivity; soil; telecommunication transmission lines; FEM; azimuthal component; conducting soils; distant observation points; finite-element method; frequency dependence; full-wave approach; induced voltages; lightning channel; lightning electromagnetic fields evaluation; lightning radiated electromagnetic fields; lightning-induced voltages; overhead lines; relative permittivity; resistivity values; soil conductivity; soil electrical parameters; Conductivity; Frequency dependence; Lightning; Magnetic domains; Permittivity; Soil; Electromagnetic fields; FEM; frequency dependence; lightning induced voltages; lightning return stroke channel;
fLanguage :
English
Journal_Title :
Electromagnetic Compatibility, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9375
Type :
jour
DOI :
10.1109/TEMC.2013.2258674
Filename :
6517983
Link To Document :
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