Protection coordination of directional overcurrent relays: new time current characteristic and objective function. Issue 1 (20th October 2017)

• Record Type: Journal Article
• Authors: Yazdaninejadi, Amin; Naderi, Mehdi S.; Gharehpetian, Gevork B.; Talavat, Vahid
• Is Part Of: IET generation, transmission & distribution. Volume 12:Issue 1(2018)
• Page Start: 190
• Page End: 199
• Publication Date: 2017-10-20
• Subjects: relay protection -- overcurrent protection -- power grids -- fault diagnosis -- power distribution protection -- nonlinear programming -- numerical analysis; protection coordination -- directional overcurrent relays -- DOCR -- time current characteristic -- objective function -- power grid faults -- meshed distribution networks -- multisource distribution networks -- classical operation time model -- auxiliary variables -- coordination constraints -- TCC -- numerical relays -- operation time -- nonlinear programming model -- particle swarm optimisation algorithm -- 8‐bus test systems -- IEEE 14‐bus test systems; Electric power production -- Periodicals; Electric power transmission -- Periodicals; Electric power distribution -- Periodicals; 621.3105
• DOI: 10.1049/iet-gtd.2017.0574
• Languages: English
• ISSNs: 1751-8687

Abstract

Abstract : Clearing power grid faults swiftly and selectively offers higher security, reliability and sustainability. Accomplishing this aim by deploying directional overcurrent relays (DOCRs) is one of the major challenges in meshed and multisource distribution networks. To overcome this challenge, the current study elaborates a new coordination strategy which concentrates on minimising overall operation time of relays. In this strategy, an auxiliary variable is added to classical operation time model of each DOCR. All the auxiliary variables are considered as coordination constraints which help to yield new and well‐defined time current characteristics (TCCs). In other words, more flexibility is attained in adjusting relay's characteristic which helps to alleviate clearing time of faults. The obtained TCCs can be easily performed by numerical relays. In addition, a new objective function is defined to steer the relay settings towards optimal solutions conveniently. It was shown that the proposed approach not only reduces the operation time of relays, but also prevents miscoordinations. This approach demonstrates a non‐linear programming model tackled by particle swarm optimisation algorithm. The effectiveness of the proposed approach is verified via 8‐bus and IEEE 14‐bus test systems and results are discussed in depth.