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Soil Ionization Due to High Pulse Transient Currents Leaked by Earth Electrodes

By Guido Ala, Maria Luisa Di Silvestre, Fabio Viola, and Elisa Francomano
Progress In Electromagnetics Research B, Vol. 14, 1-21, 2009


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.


Guido Ala, Maria Luisa Di Silvestre, Fabio Viola, and Elisa Francomano, "Soil Ionization Due to High Pulse Transient Currents Leaked by Earth Electrodes," Progress In Electromagnetics Research B, Vol. 14, 1-21, 2009.


    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

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

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

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

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