Statistical Description of Counterpoise Effective Length Based On Regressive Formulas

Authors: Petar Sarajcev, Josip Vasilj, Damir Jakus

Abstract:

This paper presents a novel statistical description of the counterpoise effective length due to lightning surges, where the (impulse) effective length had been obtained by means of regressive formulas applied to the transient simulation results. The effective length is described in terms of a statistical distribution function, from which median, mean, variance, and other parameters of interest could be readily obtained. The influence of lightning current amplitude, lightning front duration, and soil resistivity on the effective length has been accounted for, assuming statistical nature of these parameters. A method for determining the optimal counterpoise length, in terms of the statistical impulse effective length, is also presented. It is based on estimating the number of dangerous events associated with lightning strikes. Proposed statistical description and the associated method provide valuable information which could aid the design engineer in optimising physical lengths of counterpoises in different grounding arrangements and soil resistivity situations.

Keywords: Counterpoise, Grounding conductor, Effective length, Lightning, Monte Carlo method, Statistical distribution.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1099140

References:

[1] F. M. Gatta, A. Geri, S. Lauria, and M. Maccioni, “Backflashover simulation of HV transmission lines with enhanced counterpoise groundings,” Electric Power Systems Research, vol. 79, pp. 1076–1084, 2009.
[2] L. Grcev, “Improved design of power transmission line arrangements for better protection against effects of lightning,” in Proceedings of the International Symposium on Electromagnetic Compatibility, Roma, Italy, September, 14-18 1998, pp. 100–103.
[3] D. Cavka, D. Poljak, and R. Goic, “Transient analysis of grounding systems for wind turbines,” Renewable Energy, vol. 43, pp. 284–291, 2012.
[4] S. Sekioka and T. Funabashi, “Effective length of long grounding conductor in windfarm,” in International Conference on Power System Transients, Lyon, France, June, 4-7 2007.
[5] B. P. Gupta and B. Thapar, “Impulse characteristics of grounding electrodes,” Journal of the Institution of Engineering (India), vol. 61, no. 4, pp. 178–182, 1981.
[6] L. Grcev, “Impulse efficiency of ground electrodes,” IEEE Transactions on Power Delivery, vol. 24, no. 1, pp. 441–451, 2009.
[7] J. He, Y. Gao, R. Zeng, J. Zou, X. Liang, B. Zhang, J. Lee, and S. Chang, “Effective length of counterpoise wire under lightning current,” IEEE Transactions on Power Delivery, vol. 20, no. 2, pp. 1585–1591, 2005.
[8] S. Wojtas, “Lightning impulse efficiency of horizontal earthings,” Electrical Review, vol. 88, no. 10b, pp. 332–334, 2012.
[9] J.-H. Choi and B.-H. Lee, “An analysis of conventional grounding impedance based on the impulsive current distribution of a horizontal electrode,” Electric Power Systems Research, vol. 85, pp. 30–37, 2012.
[10] A. K. Mishra, N. Nagaoka, and A. Ametani, “Frequency-dependent distributed-parameter modelling of counterpoise by time-domain fitting,” IEE Proceedings – Generation, Transmission and Distribution, vol. 153, no. 4, pp. 485–492, 2006.
[11] R. S. Alipio, M. A. O. Schroeder, M. M. Afonso, and T. A. S. Oliveira, “The influence of the soil parameters dependence with frequency on impulse grounding behavior,” in X International Symposium on Lightning Protection, Curitiba, Brasil, November, 9-13 2009.
[12] J. He, R. Zeng, and B. Zhang, Methodology and Technology for Power System Grounding. Singapore: John Wiley & Sons Singapore Pte. Ltd., 2013.
[13] CIGRE, “Lightning parameters for engineering applications,” CIGRE, Tech. Rep., 2013, Working Group C4.407.
[14] IEEE WG, “Parameters of lightning strokes: A review,” IEEE Transactions on Power Delivery, vol. 20, no. 1, pp. 346–358, 2005.
[15] A. Borghetti, C. A. Nucci, and M. Paolone, “Estimation of the statistical distributions of lightning current parameters at ground level from the data recorded by instrumented towers,” IEEE Transactions on Power Delivery, vol. 19, pp. 1400–1409, 2004.
[16] J. Takami and S. Okabe, “Observational results of lightning current on transmission towers,” IEEE Transactions on Power Delivery, vol. 22, no. 1, pp. 547–556, 2007.
[17] Y. P. Tu, J. L. He, and R. Zeng, “Lightning impulse performances of grounding devices covered with low-resistivity-materials,” IEEE Transactions on Power Delivery, vol. 21, no. 3, pp. 1706–1713, 2003.
[18] W. K. Hardle and L. Simar, Applied Multivariate Statistical Analysis, 3rd ed. Berlin, Germany: Springer-Verlag, 2012.
[19] H. P. Langtangen, A Primer on Scientific Programming with Python, 3rd ed. Berlin, Germany: Springer-Verlag, 2012.
[20] IEC, “IEC 61400-24: Wind turbines – Part 24: Lightning protection,” 2010, International standard, Edition 1.0 2010-06.