Akademik Veri Yönetim Sistemi
Proceedings of the 1997 32nd Univertsities Power Engineering Conference, UPEC'97. Part 2 (of 2), Manchester, İngiltere, 10 - 12 Eylül 1997, cilt.2, ss.1106-1109
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.