volume | PIER Journals

Abstract

This paper proposes a numerical model of soil ionization phenomena that can occur when earth electrodes are injected by high pulse transient currents, as the current associated with a direct lightning stroke. Based on finite difference time domain numerical scheme, this model ascribes the electrical breakdown in the soil to the process of discharge in the air. In fact, as soon as the local electric field overcomes the electrical strength, the air in the voids trapped among soil particles is ionized, and the current is conducted by ionized plasma paths locally grow. The dimension of these ionized air channels are strictly dependent upon the local temperature. Thus, a local heat balance is enforced in order to obtain the time variable conductivity profile of the medium. This model can be implemented both for concentrated and extended electrodes, since no hypothesis has to be enforced about the geometric shape of the ionized region. Validation of the proposed model is obtained by comparing simulation results with experimental data found in technical literature.

1. Poljak, D. and V. Doric, "Wire antenna model for transient analysis of simple grounding systems, Part II: The horizontal grounding electrode," Progress In Electromagnetics Research, Vol. 64, 167-189, 2006.
doi:10.2528/PIER06062102 Google Scholar

2. Poljak, D. and V. Doric, "Wire antenna model for transient analysis of simple grounding systems, Part I: The vertical grounding electrode," Progress In Electromagnetics Research, Vol. 64, 149-166, 2006.
doi:10.2528/PIER06062101 Google Scholar

3. Grcev, L. and F. Dawalibi, "An electromagnetic model for transients in grounding systems," IEEE Trans. on Power Delivery, Vol. 5, No. 4, 1773-1781, Oct. 1990.
doi:10.1109/61.103673 Google Scholar

4. Dawalibi , F., W. Xiong, and J. Ma, "Transient performance of substation structures and associated grounding systems," IEEE Trans. on Industry Application, Vol. 31, No. 3, 520-527, May/Jun. 1995.
doi:10.1109/28.382112 Google Scholar

5. Grcev, L., "Computer analysis of transient voltages in large grounding systems," IEEE Trans. on Power Delivery, Vol. 11, No. 2, 815-823, Apr. 199.
doi:10.1109/61.489339 Google Scholar

6. Ala, G. and M. L. Di Silvestre, "A simulation model for electromagnetic transients in lightning protection systems," IEEE Trans. on Electromagnetic Compatibility, Vol. 44, No. 4, 539-554, Nov. 2002.
doi:10.1109/TEMC.2002.804773 Google Scholar

7. Geri, A., "Behaviour of grounding systems excited by high impulse currents: The model and its validation ," IEEE Trans. on Power Delivery, Vol. 14, No. 3, 1008-1017, Jul. 1999.
doi:10.1109/61.772347 Google Scholar

8. Geri, A., G. M. Veca, E. Garbagnati, and G. Sartorio, "Non-linear behaviour of ground electrodes under lightning surge currents: Computer modeling and comparison with experimental results," IEEE Trans. on Magnetics, Vol. 28, No. 2, 1442-1445, Mar. 1992.
doi:10.1109/20.123966 Google Scholar

9. Zhang, B., He, J.-B. Lee, X. Cui, Z. Zhao, J. Zou, and S.-H. Chang, "Numerical analysis of transient performance of grounding systems considering soil ionization by coupling moment method with circuit theory ," IEEE Trans. on Magnetics, Vol. 41, No. 5, 1440-1443, May 2005.
doi:10.1109/TMAG.2005.844547 Google Scholar

10. Habjanic, A. and M. Trlep, "The simulation of the soil ionization phenomenon around the grounding system by the finite element method," IEEE Trans. on Magnetics , Vol. 42, No. 4, 867-870, Apr. 2006.
doi:10.1109/TMAG.2006.871625 Google Scholar

11. Mohamad, N. N., A. Haddad, and H. Griffiths, "Characterization of ionization phenomena in soils under fast impulses," IEEE Trans. on Power Delivery , Vol. 21, No. 1, 353-361, Jan. 2006.
doi:10.1109/TPWRD.2005.852352 Google Scholar

12. Zeng, R., X. Gong, J. He, B. Zang, and Y. Gao, "Lightning impulse performance of grounding grids for substations considering soil ionization," IEEE Trans. on Power Delivery, Vol. 23, No. 2, 667-675, Apr. 2008.
doi:10.1109/TPWRD.2007.915194 Google Scholar

13. Bellaschi, P. L., "Impulse and 60-cycle characteristics of driven grounds," Trans. Am. IEE, Vol. 60, 123-128, 1941. Google Scholar

14. Liew, A. C. and M. Darveniza, "Dynamics model of impulse characteristics of concentrated earth," Proc. IEE, Vol. 121, No. 2, 123-135, Feb. 1974. Google Scholar

15. Kenneth, J. N., I. R. Jandrell, and A. J. Phillips, "A simplified model of the lightning performance of a driven rod earth electrode in multi-layer soil that includes the effect of soil ionisation," Industry Applications Conference. 41st IAS Annual Meeting Conference Record of the 2006 IEEE, Vol. 4, 1821-1825, 2006.

16. Liew, A. C., J. Wang, and M. Darveniza, "Extension of dynamic model of impulse behaviocurrentsur of concentrated earths at high ," IEEE Trans. on Power Delivery, Vol. 20, No. 3, 2160-2165, Jul. 2005. Google Scholar

17. Liu, Y., N. Theethayi, R. Thottappillil, R. M. Gonzales, and M. Zitnik, "An improved model for soil ionization around grounding system and its application to stratified soil," Journal of Electrostatics,, Vol. 60, No. 2-4, 203-209, Mar. 2004.
doi:10.1016/j.elstat.2004.01.012 Google Scholar

18. Sekioka, S., M. I. Lorentzou, M. P. Philippakou, and J. M. Prousalidis, "Current dependent grounding resistance model based on energy balance of soil ionization," IEEE Trans. on Power Delivery, Vol. 21, No. 1, 194-201, Jan. 2006.
doi:10.1109/TPWRD.2005.852337 Google Scholar

19. Leadon, R. E., T. M. Flanagen, C. E. Mallon, and R. Denson, "Effect of ambient gas on ARC initiation characteristics in soil ," IEEE Trans. on Nuclear Science, Vol. 30, No. 6, 4572-4576, Nov. 1983.
doi:10.1109/TNS.1983.4333173 Google Scholar

20. Ala, G., P. L. Buccheri, P. Romano, and F. Viola, "Finite difference time domain simulation of earth electrodes soil ionization under lightning surge condition," IET Science, Measurement and Technology, Vol. 2, No. 3, 134-145, May 2008.
doi:10.1049/iet-smt:20070001 Google Scholar

21. Cooray, V., M. Zitnik, M. Manyahi, R. Montano, M. Rahman, and Y. Liu, "Physical model of surge current characteristics of buried vertical rods in the presence of soil ionization," Journal of Electrostatics, Vol. 60, No. 2-4, 193-202, Mar. 2004.
doi:10.1016/j.elstat.2004.01.017 Google Scholar

22. Mousa, A. M., "The soil ionization gradient associated with discharge of high currents into concentrated electrodes," IEEE Trans. on Power Delivery , Vol. 9, 1669-1677, Jul. 1994. Google Scholar

23. D'Angola, A., M. Capitelli, G. Colonna, and C. Gorse, "Transport properties of high temperature air in local thermodynamic equilibrium," The European Physical Journal D, Atomic, Molecular, Optical and Plasma Physics, Vol. 11, No. 2, 279-289, Jul. 2000. Google Scholar

24. Capitelli, M., G. Colonna, and A. D'Angola, "Thermodynamic properties and transport coefficients of high temperature air," Pulsed Power Plasma Science. PPPS-2001. Digest of Technical Papers, Vol. 1, No. 7-22, 694-697, Jun. 2001. Google Scholar

25. Prager, J., G. Baldea, U. Riedel, and J. Warnatz, "Equilibrium composition and electrical conductivity of high-temperature air," 21st ICDERS, 23-27, Jul. 2007. Google Scholar

26. Yee, K. S., "Numerical solution of initial boundary value problems involving Maxwell's equations in isotropic media," IEEE Trans. on Antennas and Propagation, Vol. 14, 302-307, 1966. Google Scholar

27. Taflove, A. and S. Hagness, Computational Electro Dynamics: The Finite-difference Time-domain Method, Artech House, 2000.

28. Sullivan, D. M., Electromagnetic Simulation Using the FDTD Method, IEEE Press Series on RF and Microwave Technology, Jul. Jul. 2000.

29. Cassie, A. M., Arc rupture and circuit severity: A new theorie, No. 102 CIGRE Report, Paris, France, 1939.

30. Noda, T. and S. Yokoyama, "Thin wire representation in finite difference time domain surge simulation," IEEE Trans. on Power Delivery, Vol. 17, No. 3, 840-847, Jul. 2002.
doi:10.1109/TPWRD.2002.1022813 Google Scholar

Professor Guido Ala

Dr. Maria Luisa Di Silvestre

Professor Fabio Viola

Prof. Elisa Francomano