Comparison of fault current calculation techniques for analysing earthing system performance


HOCAOĞLU M. H., Griffiths H.

Proceedings of the 1997 32nd Univertsities Power Engineering Conference, UPEC'97. Part 2 (of 2), Manchester, England, 10 - 12 September 1997, vol.2, pp.1106-1109 identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 2
  • City: Manchester
  • Country: England
  • Page Numbers: pp.1106-1109
  • İstanbul Ticaret University Affiliated: Yes

Abstract

Recent developments in computer technology and numerical techniques now enable full dynamic studies to be carried for fault current calculations. Existing international standards, however, are still based on hand-calculation approaches. Generally, fault current calculations are required to determine fault current interruption requirements and, in the main, consider three-phase balanced faults. However, fault current calculations are also required to establish the extent and structural design of earthing systems, and in this case the accurate calculation of single line-to-earth type of fault is required. In this paper, a review of existing earthing standards with respect to their fault current assessment techniques is represented and different fault current calculation techniques are compared on a simple network. In addition, a case study is presented based of an actual system to demonstrate the difference between dynamic and steady-state fault current calculations of earth fault current magnitude. The results show that, magnitude of the short circuit current highly over estimated by steady-state fault current calculation techniques. Also, there is clearly a need to asses dynamic potential rise specifically for systems at 132 kV and above.