A novel scheme for current-only directional overcurrent relay

Current‐based directional relaying scheme to protect series compensated transmission lines used to transmit bulk power produced by power electronics interfaced renewable energy power plants

“…Reverse faults: Similar to steps taken for forward faults, (10) to (14) can be derived for reverse faults according to Fig. 3a…”

“…A comparison between (9) and (14) reveals that there is 180° (π rad ) difference between the phase angle of Δ in forward and reverse faults. Therefore, the relay would be able to distinguish between forward and reverse faults properly.…”

“…To solve this problem, increasing the sampling rate has been proposed while it will increase the complexity and computational burden of the approach. A current only directional relaying scheme has been proposed in [14], which used samples of superimposed current components to detect the fault direction. The performance of this scheme has been affected by the threshold value.…”

“…The performance of this scheme has been affected by the threshold value. Since the introduced approach in [14] employed pre-fault current samples to detect the fault direction, its algorithm needs to be updated by power flow direction state in power system; consequently, it will lose its performance ability during reverse power flow, leading to limiting its application to where the potential transformer (PT) is available. Therefore, the main objective of the study is to provide a simple and highly efficient directional relaying scheme, which is able to detect fault direction in SCTLs integrated with PE-REPPs.…”

Yeni Nesil Elektrik Dağıtım Şebekeleri İçin Çok Fonksiyonlu Dijital Aşırı Akım Rölesi Tasarımı ve Geliştirilmesi

“…Polarizasyon miktarı olarak arıza öncesi akım sinyalini kullanır. Algoritma, arızanın yönünü tespit etmek için mevcut sinyalin üst üste binen bileşenini kullanır ve bu algoritma fazör tahmini gerektirmez[12].Ağ topolojisi değişikliği, örgü ağdaki yönlü aşırı akım rölelerinin koordinasyonunu etkileyen sorunlardan biridir. Hattın bir tarafındaki rölenin hattın diğer tarafındaki röleye göre daha hızlı çalışması, ağ topolojisinin hata sırasında değişmesine neden olur ve diğer taraf rölesinden ve onun yedek rölesinden geçen kısa devre akımında değişikliğe neden olur.…”