Controlled large-scale tests of practical grounding electrodes - Part II: Comparison of analytical and numerical predictions with experimental results

D. Clark, Dongsheng Guo, D. Lathi, N. Harid, H. Griffiths, Alan Ainsley, A. Haddad

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

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.

Original languageBritish English
Article number6742638
Pages (from-to)1240-1248
Number of pages9
JournalIEEE Transactions on Power Delivery
Volume29
Issue number3
DOIs
StatePublished - Jun 2014

Keywords

  • Conductivity
  • electric variables measurement
  • grounding
  • grounding electrodes
  • impedance
  • impedance measurement
  • impulse testing
  • resistance measurement
  • simulation
  • transient analysis

Fingerprint

Dive into the research topics of 'Controlled large-scale tests of practical grounding electrodes - Part II: Comparison of analytical and numerical predictions with experimental results'. Together they form a unique fingerprint.

Cite this