Open AccessPartial operating current characteristics to discriminate internal and external faults of differential protection zones during CT saturation
Author(s) -
Hossain Monir,
Leevongwat Ittiphong,
Rastgoufard Parviz
Publication year - 2018
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2017.0283
Subject(s) - differential protection , saturation (graph theory) , current (fluid) , control theory (sociology) , materials science , geology , mechanics , computer science , voltage , mathematics , engineering , physics , electrical engineering , artificial intelligence , control (management) , transformer , combinatorics
To protect transformers, transmission lines and busbar systems, low impedance current differential protection schemes based on percentage restraint characteristics are widely used in power systems. The main application issue of these schemes is mis‐operation due to current transformer (CT) saturation during close‐in external faults. A comprehensive fault discrimination algorithm is highly required for current differential protection schemes to overcome the CT saturation issue. The purpose of this study is to introduce a methodology based on partial operating current (POC) characteristics which discriminate internal and external faults of differential protection zones. The study includes the mathematical model of POC characteristics, a fault discriminating algorithm using POC features, and bus differential protection zone results. The results documented encompasses various possible short‐circuit (fault) scenarios and indicate the capability of the proposed algorithm in discriminating internal and external faults under CT saturation conditions.