Enhanced real time coordination of distance and user defined over current relays. (June 2018)

• Record Type: Journal Article
• Authors: Singh, Manohar; Telukunta, Vishnuvardhan; Srivani, S.G.
• Is Part Of: International journal of electrical power & energy systems. Volume 98(2018)
• Page Start: 430
• Page End: 441
• Publication Date: 2018-06
• Subjects: Distance relays -- Optimization -- Hardware in-loop testing -- Real time and user defined time inverse relay characteristics; Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2017.12.018
• Languages: English
• ISSNs: 0142-0615

Abstract

Highlights: Modified combined distance and over current relay coordination. User defined time inverse relay characteristics are developed to improve the operating time of backup relays. Adaptive feature for zone-2 of main distance relays. Hardware in loop validation of the proposed relay coordination in real time using RTDS. In real time the performance is evaluated for different faults and faults resistances. Abstract: Faults on the transmission lines are primarily cleared by pilot wire differential protection as well as from zone-1 and zone-2 of distance relays, depending upon their location on the lines. If the main distance relays fails to operate, then standard time inverse directional over current ( DOCR ) relays are set as backup protection in coordination with main distance relays. The desired coordination time margins between main distance relays and backup standard time inverse over current relays should be maintained at start of zone-1 and zone-2 of distance relays. Coordination of fixed zone-2 setting of distance relays with standard time inverse relays results in poor tripping time of backup DOCR . In this research article, zone -2 setting of distance relays are made adaptive, so that minimum coordination time margin is maintained for complete reach of distance relays. User defined time inverse over current relays are proposed in conjugation with flexible feature of zone-2 setting of distance for improving the operating time of backup DOCR s. The performance of the proposed algorithm is validated in real time simulation with hardware in loop testing of numerical distance and user defined DOCR . From hardware in loop simulation results, it is observed that the performance of the proposed combined distance & DOCR coordination algorithm is in close concurrence with simulated results. The sensitivity of proposed algorithm is checked for different phase as well as ground faults with different fault resistance and it is also observed that the proposed algorithm is highly robust for different fault conditions.