Analysis of Lightning-Induced Voltages on Overhead Lines Using a 2-D FDTD Method and Agrawal Coupling Model

In this paper, the lightning-generated electromagnetic fields over lossy ground produced by lightning strikes either to flat ground or to a tall tower are calculated using the 2-D finite-difference time-domain (FDTD) method. The resultant horizontal and vertical electric fields are used as forcing functions in the discretized Agrawal electromagnetic coupling equations for the calculation of induced voltages on overhead horizontal conductors without employing the Cooray-Rubinstein formula. Comparison of the results with those obtained using the 3-D FDTD method and with experimental data found in the literature is used to test the validity of the examined method. The approach employed here generally provides sufficient accuracy while allowing significant reduction in computation time and storage requirements as compared to the 3-D FDTD method. From the analysis carried out in this paper, induced voltages appear to be strongly dependent on ground conductivity, somewhat influenced by return-stroke speed, and essentially independent of return-stroke model [transmission-line (TL), modified transmission line with linear current decay with height (MTLL), or modified transmission line with exponential current decaywith height (MTLE)].

[1]  Vernon Cooray,et al.  Horizontal fields generated by return strokes , 1992 .

[2]  Ashok K. Agrawal,et al.  Transient Response of Multiconductor Transmission Lines Excited by a Nonuniform Electromagnetic Field , 1980 .

[3]  T. A. Short,et al.  Induced voltage measurements on an experimental distribution line during nearby rocket triggered lightning flashes , 1996 .

[4]  M. Uman,et al.  Magnetic field of lightning return stroke , 1969 .

[5]  Hans Kristian Hoidalen,et al.  Analytical formulation of lightning-induced voltages on multiconductor overhead lines above lossy ground , 2003 .

[6]  Vernon Cooray,et al.  Lightning-induced overvoltages in power lines: validity of various approximations made in overvoltage calculations , 1998 .

[7]  Vernon Cooray.  Some considerations on the "Cooray-Rubinstein" formulation used in deriving the horizontal electric field of lightning return strokes over finitely conducting ground , 2002 .

[8]  M. Uman,et al.  Lightning return stroke current models with specified channel‐base current: A review and comparison , 1990 .

[9]  S.H.H. Sadeghi,et al.  Analysis of lightning-radiated electromagnetic fields in the vicinity of lossy ground , 2005, IEEE Transactions on Electromagnetic Compatibility.

[10]  C. Yang,et al.  Calculation methods of electromagnetic fields very close to lightning , 2004, IEEE Transactions on Electromagnetic Compatibility.

[11]  M. Ianoz,et al.  Influence of a lossy ground on lightning-induced voltages on overhead lines , 1996 .

[12]  Pritindra Chowdhuri,et al.  Voltage surges induced on overhead lines by lightning strokes , 1967 .

[13]  Masaru Ishii,et al.  Voltage induced on a test distribution line by negative winter lightning strokes to a tall structure , 2003 .

[14]  Yoshihiro Baba,et al.  On the use of lumped sources in lightning return stroke models , 2005 .

[15]  S. Rusck,et al.  Induced-lightning overvoltages on power transmission lines with special reference to the overvoltage protection of low voltage networks , 1958 .

[16]  James R. Wait,et al.  Concerning the horizontal electric field of lightning , 1997 .

[17]  Farhad Rachidi,et al.  Formulation of the field-to-transmission line coupling equations in terms of magnetic excitation field , 1993 .

[18]  Yoshihiro Baba,et al.  Lightning electromagnetic environment in the presence of a tall grounded strike object , 2005 .

[19]  M. Ianoz,et al.  On lightning return stroke models for LEMP calculations , 1988 .

[20]  Y. Baba,et al.  Voltages induced on an overhead wire by lightning strikes to a nearby tall grounded object , 2006, IEEE Transactions on Electromagnetic Compatibility.

[21]  M. Rubinstein,et al.  An approximate formula for the calculation of the horizontal electric field from lightning at close, intermediate, and long range , 1996 .

[22]  C. Taylor,et al.  The response of a terminated two-wire transmission line excited by a nonuniform electromagnetic field , 1965 .

[23]  G. Mur.  Absorbing Boundary Conditions for the Finite-Difference Approximation of the Time-Domain Electromagnetic-Field Equations , 1981, IEEE Transactions on Electromagnetic Compatibility.