Controlled Large-Scale Tests of Practical Grounding Electrodes—Part II: Comparison of Analytical and Numerical Predictions With Experimental Results

Autor:	Huw Griffiths, Noureddine Harid, Alan Ainsley, D. Lathi, D. Guo, David Clark, Abderrahmane Haddad
Rok vydání:	2014
Předmět:	Engineering Ground business.industry Extrapolation Impedance matching Energy Engineering and Power Technology Mechanics High impedance Electronic engineering Damping factor Output impedance Voltage source Electrical and Electronic Engineering business Electrical impedance
Zdroj:	IEEE Transactions on Power Delivery. 29:1240-1248
ISSN:	1937-4208 0885-8977
Popis:	This paper presents tests carried out at an outdoor experimental facility, described in the companion Part 1 paper, to investigate the performance of practical grounding systems. Here, the results of low-voltage dc, ac, and impulse tests performed on rod and grid electrodes are described, and the measured quantities are compared with computed values obtained from numerical models. Measured ground resistance and impedance at low frequency (including power frequency) showed reasonable agreement with simple standard formulae and computational models, but revealed a significant falloff with current magnitude in the range often used for practical testing of high-voltage grounding systems. This may have implications for the specifications of grounding test equipment and extrapolation of measured ground resistance/impedance at low-voltage/current to values representative of realistic fault currents. A frequency dependence of ground impedance was also measured. Specifically, a fall in impedance over a frequency range up to 100 kHz is not generally accounted for in grounding models.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::a67e5356024be6b49c53a8a1cb791538 https://doi.org/10.1109/tpwrd.2014.2298358 Zobrazit plný text záznamu