A New Strategy for Determining Fault Zones in Distance Relays

• Published in: IEEE transactions on power delivery 2008-10, Vol.23 (4), p.1857-1863
• Main Authors: Gilany, M., Al-Kandari, A., Madouh, J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Availability; Backups; Boundaries; Circuit faults; Commands; Connection and protection apparatus; Distance relays; Electrical engineering. Electrical power engineering; Exact sciences and technology; Exchanging; fault zones; Faults; Impedance; Integrated circuit interconnections; Networks; pilot schemes; Power system faults; Power system protection; Power system relaying; Protective relaying; Relays; setting problems; Stations; Strategy; Substation protection
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/TPWRD.2008.2002871

A new strategy (denoted P-SS) for estimating the correct fault zone in distance relays is introduced. The main difference between the P-SS and conventional setting strategies is that the P-SS does not depend on fixed boundaries for backup zones. It depends on exchanging information between local relays in the same station in addition to a command from the remote end relay. With the proposed strategy, zone-1 covers the entire length of the protected line, zone-2 covers the entire length of any next line irrespective of its length, and zone-3 covers the entire length of any line next to zone-2. The governing rules for the proposed strategy are presented. The strategy is examined against a wide range of setting problems of a real part of a high-voltage network with real relay settings. The results confirm that the P-SS achieves the required accurate, sensitive, and selective relay operation.