Technique for Grounding System Design in Distribution Substation

Authors: N. Rugthaicharoencheep, A. Charlangsut, B. Ainsuk, A. Phayomhom

Abstract:

This paper presents the significant factor and give some suggestion that should know before design. The main objective of this paper is guide the first step for someone who attends to design of grounding system before study in details later. The overview of grounding system can protect damage from fault such as can save a human life and power system equipment. The unsafe conditions have three cases. Case 1) maximum touch voltage exceeds the safety criteria. In this case, the conductor compression ratio of the ground gird should be first adjusted to have optimal spacing of ground grid conductors. If it still over limit, earth resistivity should be consider afterward. Case 2) maximum step voltage exceeds the safety criteria. In this case, increasing the number of ground grid conductors around the boundary can solve this problem. Case 3) both of maximum touch and step voltage exceed the safety criteria. In this case, follow the solutions explained in case 1 and case 2. Another suggestion, vary depth of ground grid until maximum step and touch voltage do not exceed the safety criteria.

Keywords: Grounding System, Touch Voltage, Step Voltage, Safety Criteria.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1060058

References:

[1] T. Thasananutariya, K. Spuntupong, and S. Chatratana, "Design of Grounding System for GIS Indoor Substation", in Proc. TENCON IEEE Region 10 Conf. pp. 413 - 416, 2004.
[2] IEEE Std 80-2000, "IEEE Guide for Safety in AC Substation Grounding", 2000.
[3] ANSI/IEEE Std 81-1983, "IEEE Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Ground System",1983.
[4] A. Phayomhom, S. Sirisumranikul, T. Kasirawat and A. Puttarach, "Safety Design Planning of Ground Grid for Outdoor Substation in MEA-s Power Distribution System", in Proc. Electrical Engineering/ Electronics Computer Telecom. and Information Technology International Conf. pp. 298-302, 2010.
[5] P. A. Zotos, "Ground Grid Design in Large Industrial Plants", IEEE Tran. Industry Applications, vol. 24, no. 3, pp.521-525, May/June, 1988.
[6] IEEE Std 367-1996, "IEEE Recommended Practice for Determining the Electric Power Station Ground Potential Rise and Induced Voltage From a Power Fault", 1996.
[7] M. Mitolo, P. E. Sutherland and R. Natarajan, "Effects of High Fault Currents on Ground Grid Design", IEEE Trans. Industry Applications, vol. 46, no. 3,May/June, 2010
[8] A. Puttarach, N. Chakpitak, T.Kasirawat, and C. Pongsriwat, "Substation Grounding Grid Analysis with theVariation of Soil layer depth Method",in Proc. IEEE Lausanne, Power Tech. pp. 1881-1886, 2007.
[9] H. M. Khodr, G. A. Salloum, J. T. Saraiva, and M.A. Matos, "Design of grounding systems in substations using a mixed-integerlinear programming formulation", Electric Power Systems Research, Vol. 79, pp. 126-133, 2007.
[10] A. Phayomhom, S. Sirisumrannukul, T.Kasirawat, A. Puttarach, C. Klinsopon, and P. Pearnont, "Safety Analysis for Grounding System of Two Neighbouring Substations: Case Study of Metropolitan ElectricityAuthority-s System", GMSARN International Journal 5 pp. 169 - 178, 2011.
[11] Marcus O. Durham, and Robert A. Durham, "Grounding System Designfor IsolatedLocationsand Plant Systems",in Proc. Petroleum and chemical Industry Conf. pp. 145-153, 1995.
[12] Yanqing GAO, Rong Zeng, Xidong Liang, Jinliang HE, Weimin Sun and Qi SU, "Safety Analysis of Grounding Grid for Substation with Different Structure",In Proc. Power System Tech. International Conf. pp. 1487-1492, 2000.
[13] F.Dawalibi, and D.Mukhedkar, "Optimum Designof Substation Grounding in a Two Layer Earth StructurePart III Study of Grounding Grids Performanceandnew Electrodes Configuration",IEEE Tran. Power Apparatus and Systems, vol. 94, no. 2, pp. 267-282, March/April, 1975.
[14] Jinliang He, RongZeng, YanqingGao, YoupingTu, Weimin Sun, Jun Zou,and Zhicheng Guan, "Seasonal Influences on Safety of Substation Grounding System", IEEE Tran. Power Delivery, vol. 18, no. 3, pp. 788-795, July, 2003.