Time Characteristic Curve Based Earth Fault Relay Selectivity Assessment for Optimal Overcurrent Relay Coordination in Distribution Networks

Atsever M. B., Hocaoğlu M. H.

57th International Universities Power Engineering Conference: Big Data and Smart Grids, UPEC 2022, İstanbul, Türkiye, 30 Ağustos - 02 Eylül 2022 identifier identifier

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Doi Numarası: 10.1109/upec55022.2022.9917673
  • Basıldığı Şehir: İstanbul
  • Basıldığı Ülke: Türkiye
  • Anahtar Kelimeler: optimization, relay coordination, earth fault
  • İstanbul Ticaret Üniversitesi Adresli: Evet

Özet

Coordination of overcurrent relays has been handled with optimization techniques. Time and pick up settings are optimized by using three-phase fault magnitudes. Generally, Standard Inverse Characteristic (SIC) has been used for three-phase fault protection settings. However, single line to earth fault is the most common fault types in distribution networks. Definite Time Characteristic (DTC) is, widely, used for coordination of earth fault relays. Topology type, neutral earthing resistance and capacitive currents of underground cables may cause selectivity issues when DTC is used for the coordination. In this work, time characteristic curve (TCC) based earth fault relay selectivity assessment carried out on distribution network. Different earthing resistance and TCC are taken into account during optimization processes. Results show that both DTC and SIC have issues in terms of operating time and selective protection.