Title :
Design and Performance Evaluation of a High-Impedance REF Scheme for MV/LV Transformers
Author :
Apostolopoulos, Christos ; Tsakiris, Dimitris
Author_Institution :
PROTASIS SA, Athens, Greece
Abstract :
This paper presents the detailed engineering study conducted to design a high-impedance restricted earth fault (REF) scheme for four 11/0.415-kV, Dyn11, and 2500-kVA power transformers in an industrial power system. Analytical calculations carried out to specify the components constituting the REF scheme and to determine the appropriate relay settings are provided. The proposed REF scheme is evaluated using reliable Alternative Transients Program-Electromagnetic Transients Program simulations. The obtained results validate the adequacy of the design and highlight the advantages of using such a protection, such as fast and reliable operation even under severe current transformer saturation conditions.
Keywords :
EMTP; electrical faults; power transformers; alternative transients program simulations; apparent power 2500 kVA; electromagnetic transients program simulations; high-impedance REF performance; industrial power system; low voltage transformer; medium voltage transformer; power transformers; restricted earth fault; voltage 0.415 kV; voltage 11 kV; Circuit faults; Current transformers; Earth; Impedance; Power transformers; Relays; Resistors; ATP-EMTP; Alternative Transients Program???Electromagnetic Transients Program (ATP???EMTP); CT saturation; Restricted earth fault protection; current transformer (CT) saturation; high impedance; high-impedance; protective relaying; restricted earth fault (REF) protection;
Journal_Title :
Industry Applications, IEEE Transactions on
DOI :
10.1109/TIA.2015.2435003
