Frequency-dependent grounding impedance of the counterpoise based on the dispersed currents

- Journal title : Journal of Electrical Engineering and Technology
- Volume 7, Issue 4, 2012, pp.589-595
- Publisher : The Korean Institute of Electrical Engineers
- DOI : 10.5370/JEET.2012.7.4.589

Title & Authors

Frequency-dependent grounding impedance of the counterpoise based on the dispersed currents

Choi, Jong-Hyuk; Lee, Bok-Hee; Paek, Seung-Kwon;

Choi, Jong-Hyuk; Lee, Bok-Hee; Paek, Seung-Kwon;

Abstract

When surges and electromagnetic pulses from lightning or power conversion devices are considered, it is desirable to evaluate grounding system performance as grounding impedance. In the case of large-sized grounding electrodes or long counterpoises, the grounding impedance is increased with increasing the frequency of injected current. The grounding impedance is increased by the inductance of grounding electrodes. This paper presents the measured results of frequency-dependent grounding impedance and impedance phase as a function of the length of counterpoises. In order to analyze the frequency-dependent grounding impedance of the counterpoises, the frequency-dependent current dissipation rates were measured and simulated by the distributed parameter circuit model reflecting the frequency-dependent relative resistivity and permittivity of soil. As a result, the ground current dissipation rate is proportional to the soil resistivity near the counterpoises in a low frequency. On the other hand, the ground current dissipation near the injection point is increased as the frequency of injected current increases. Since the high frequency ground current cannot reach the far end of long counterpoise, the grounding impedance of long counterpoise approaches that of the short one in the high frequency. The results obtained from this work could be applied in design of grounding systems.

Keywords

Grounding impedance;Ground current dissipation;Distributed parameter circuit model;Counterpoise;Soil resistivity;

Language

English

Cited by

1.

Potential Rise Characteristics of a Grounding Grid Subjected to Lightning Currents,;;

1.

2.

3.

References

1.

B. Nekhoul, P. Labie, F. X. Zgainski, G. Meunier, "Calculating the Impedance of a Grounding System", IEEE Trans. on Magnetics. Vol.32, No.3, pp.1509- 1512, 1996.

2.

Y. Liu, N. Theethayi, R. Thottappillil, "Investigating the validity of existing definitions and empirical equations of effective length/area of grounding wire/grid for transient studies", Journal of Electrostatics, Vol. 65, pp.329-335, 2007.

3.

Korea Electric Association, "Korea Electrotechnical Regulation", 2009.

4.

British Standards Institution, "Protection of structures against lightning", BS 6651, 1999.

5.

M. Heimbach, L. D. Grcev, "Grounding System Analysis in Transients Programs Applying Electromagnetic Field Approach", IEEE Trans. Power Del. Vol. 12, No. 1, pp. 186-193, 1997.

6.

A. Rousseau, P. Gruet, "Practical high frequency measurement of a lightning earthing system." Proc. 27th ICLP, pp.526-530, 2004.

7.

P. Llovera, J. A. LLiso, A. Quijano, V. Fuster, "High frequency measurements of grounding impedance on resistive soils", Proc. 28th ICLP, pp.727-729, 2006.

8.

B. R. Gupta, B. Thapar, "Impulse Impedance of Grounding Grides", IEEE Trans. P.A.S., Vol. PAS-99, No. 6, pp. 2357-2362, 1980.

9.

S. Visacro, "A Comprehensive Approach to the Grounding Response to Lightning Currents", IEEE Trans. on P.D., Vol. 22 No. 1, pp.381-386, 2007.

10.

IEEE Std. 142, Grounding of Industrial and Commercial Power Systems", pp.161-164, 2007

11.

H. Motoyama, "Electromagnetic Transient Response of Buried Bare Wire and Ground Grid", IEEE Trans. Power Del. Vol. 22, No. 3, pp. 1673-1679, 2007.

12.

IEEE Std. 81.2-1991, "IEEE Guide for Measurement of Impedance and Safety Characteristics of Large, Extended or Interconnected Grounding Systems"

13.

M. E. Almeida and M.T. Correia de Barros, "Fundamental considerations on long ground electrodes design", Proc. 13th ISH, pp.241-244, 2003.

14.

C. Mazzetti and D. Mukhedkr, "Impulse to impedance of buried ground wires", IEEE Trans. PAS, Vol. PAS-102, No.9, pp.3148-3156, 1983.

15.

Bok-Hee Lee, Jeong-Hyeon Joe, Jong-Hyuk Choi, "Simulations of Frequency-dependent Impedance of Ground Rods Considering Multi-layered Soil Structures", JEET, Vol.4, No.4, pp.531-537, 2009.

16.

C. M. Portela, J. B. Gertrudes, M. C. Tavares, J. Pissolato, "Earth conductivity and permittivity data measurements: Influence in transmission line transient performance", Electric Power Systems Research, Vol. 76, pp.907-915, 2006.

17.

S. Visacro, R. Alipio, M. H. M. Vale, C. Pereira, "The Response of Grounding Electrodes to Lightning Currents: The Effect of Frequency-Dependent Soil Resistivity and Permittivity", IEEE Trans. on EMC, Vol. 53, No. 2, pp.401-406, 2011.

18.

ASTM G57-95a, "Standard test method for field measurement of soil resistivity using the wenner four-electrode method".

19.

S. Visacro and C. Portela, "Soil permittivity and conductivity behavior on frequency range of transient phenomena in electric power systems", Proc. ISH-87, Germany, Aug. 1987.