Simple current‐based algorithm for directional relays. Issue 17 (15th September 2017)

• Record Type: Journal Article
• Authors: Jafarabadi Ashtiani, Hamid; Samet, Haidar; Ghanbari, Teymoor
• Is Part Of: IET generation, transmission & distribution. Volume 11:Issue 17(2017)
• Page Start: 4227
• Page End: 4237
• Publication Date: 2017-09-15
• Subjects: relay protection -- overcurrent protection -- fault currents -- power grids -- power distribution faults -- power distribution protection -- power system stability -- fault diagnosis -- load flow; simple current‐based algorithm -- directional relays -- power grids -- fault current -- distribution networks -- distributed generation resources -- transmission networks -- overcurrent relays -- power system stability -- post‐fault current phasor -- power flow direction -- fault direction detection; Electric power production -- Periodicals; Electric power transmission -- Periodicals; Electric power distribution -- Periodicals; 621.3105
• DOI: 10.1049/iet-gtd.2017.0058
• Languages: English
• ISSNs: 1751-8687

Abstract

Abstract : In power grids, directional relays are used in situations that direction of fault current is not fixed. Distribution networks including distributed generation (DG) resources and transmission networks are some of these situations. Directional relays as key elements of distance and over current relays provide selectivity for these protections to improve their performance and power systems stability. In this study, a directional algorithm is proposed, which is able to discriminate fault direction just by sign of imaginary part of post‐fault current phasor. To evaluate the algorithm, plenty of simulations and experiments are carried out in different fault conditions. Moreover, impact of power flow direction at normal operation of the power system is considered in the evaluation of the algorithm. Also, its performance is compared with some other directional algorithms. The results confirm that the proposed algorithm is able to detect fault direction with high degree of accuracy. Moreover, simplicity of the algorithm represents its competence for practical implementation in transmission and distribution networks.