Earth Potential Rise (EPR) Computation for a Fault on Transmission Mains Pole

Authors: M. Nassereddine, J. Rizk, A. Hellany, M. Nagrial

Abstract:

The prologue of new High Voltage (HV) transmission mains into the community necessitates earthing design to ensure safety compliance of the system. Conductive structures such as steel or concrete poles are widely used in HV transmission mains. The earth potential rise (EPR) generated by a fault on these structures could result to an unsafe condition. This paper discusses information on the input impedance of the over head earth wire (OHEW) system for finite and infinite transmission mains. The definition of finite and infinite system is discussed, maximum EPR due to pole fault. The simplified equations for EPR assessments are introduced and discussed for the finite and infinite conditions. A case study is also shown.

Keywords: Coupling Factor, Earth Grid, EPR, Fault Current Distribution, High Voltage, Line Impedance, OHEW, Split Factor, Transmission Mains.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1328021

References:

[1] Andrenyi J. "Analysis of Transmission Tower Potentials During Ground Faults" IEEE Transaction on Power Apparatus and Systems, Vol. Pas- 86, No. 10, 1967
[2] Nassereddine M, Hellany A, Rizk J, "How to design an effective earthing system to ensure the safety of the people" International Conference on Advances in Computational Tools for Engineering Applications, pp 416-421, 2009
[3] Nassereddine M, Hellany A, Nagrial M, "Analysis of the impact of the OHEW under full load and fault current" International Jurnal of Energy and Environment (IJEE), Volume 1, Issue 4, pp. 727-736. 2010
[4] Nassereddine M, Hellany A, Nagrial M. Rizk J. "Soil Resistivity Structure and its implication on the Earth Grid of HV substation" World Academy of Science, engineering and Technology , Vol 60, pp 1322- 1326, 2011
[5] Nassereddine M, Hellany A, "AC Interference Study on Pipeline: the Impact of the OHEW under Full Load and Fault Current", Proceeding in the 2009 International Conference on Computer and Electrical Engineering, pp 497-501, 2009
[6] Nassereddine M, Hellany A, Nagrial M. Rizk J. " Safety Compliance of Substation Earthing Design" World Academy of Science, engineering and Technology , Vol 60, pp 525-529, 2011
[7] IEEE guide to safety in AC substation grounding, 2000- (IEEE, New York, 2000).
[8] Dawalibi F. "Effects of Sustained Ground Fault Current on Concrete poles", 1982 IEEE Transactions on Power Apparatus and Systems, Vol. PAS-101
[9] Verma, R. "Ground fault current distribution in substation, tower and ground wire" IEEE transactions on power apparatus and systems, Vol. PAS-98, 1979