Analysis of a Large Grounding System and Subsequent Field Test Validation Using the Fall of Potential MethodReport as inadecuate




Analysis of a Large Grounding System and Subsequent Field Test Validation Using the Fall of Potential Method - Download this document for free, or read online. Document in PDF available to download.

This paper examines various aspects of the designprocess and subsequent field test measurements of a large and complexsubstation grounding system. The study and measurements show that soillayering and lead interference can have a significant impact on the appropriatetest location that yields the exact substation ground impedance. Applying a specificpercentage rule such as the 61.8% rule for uniform soils to obtain the trueground impedance may lead to unacceptable errors for large grounding systems.This poses significant problems when attempting to validate a design based onraw test data that are interpreted using approximate methods to evaluatesubstation ground impedance, and determine ground potential rise GPR, touchand step voltages. Advanced measurement methodologies and modern softwarepackages were used to obtain and effectively analyze fall of potential testdata, compute fault current distribution, and evaluate touch and step voltagesfor this large substation. Fault current distribution between the groundingsystem and other metallic paths were computed to determine the portion of faultcurrent discharged in the grounding system. The performance of the groundingsystem, including its GPR and touch and step voltages, has been accuratelycomputed and measured, taking into account the impedance of the steel materialused of the ground conductors and circulating currents within the substationgrounding system.

KEYWORDS

Ground Resistance; Fall-of-Potential; Ground Impedance Measurement; Ground Potential Rise; Ground Potential Difference; Touch Voltage; Step Voltage; Steel Conductors

Cite this paper

H. Huang, H. Liu, H. Luo, H. Du, Y. Xing, Y. Li, F. P. Dawalibi, H. Zhou and L. Fu -Analysis of a Large Grounding System and Subsequent Field Test Validation Using the Fall of Potential Method,- Energy and Power Engineering, Vol. 5 No. 4B, 2013, pp. 1266-1272. doi: 10.4236-epe.2013.54B240.





Author: Huan Huang, Hualin Liu, Hong Luo, Hao Du, Yi Xing, Yexu Li, Farid P. Dawalibi, Haijun Zhou, Longhai Fu

Source: http://www.scirp.org/



DOWNLOAD PDF




Related documents