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Identifying magnetizing inrush in power transformers based on symmetry of current waveforms
Author(s) -
Zhang Luliang,
Li Mengshi,
Ji Tianyao,
Zeng Jie
Publication year - 2017
Publication title -
ieej transactions on electrical and electronic engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.254
H-Index - 30
eISSN - 1931-4981
pISSN - 1931-4973
DOI - 10.1002/tee.22488
Subject(s) - inrush current , transformer , waveform , symmetrical components , differential protection , similarity (geometry) , computer science , electronic engineering , engineering , voltage , control theory (sociology) , electrical engineering , artificial intelligence , control (management) , image (mathematics)
This letter proposes a novel method for the discrimination between magnetizing inrush and internal fault in power transformers based on the similarity of the current waveforms. The proposed method first normalizes and sorts the sample points of the differential current in a full fundamental frequency cycle to obtain a new sequence which is independent of the magnitude and initial phase angle of the original signal. Afterward, three indices are introduced to measure the similarity between the new sequence and a template, which are used to discriminate the inrush from an internal fault. Simulation studies demonstrate the effectiveness of the proposed method and its advantages over the conventional second harmonic restraint method. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.