DocumentCode :
2584723
Title :
Transformer Fault Analysis Using Event Oscillography
Author :
Labuschagne, Casper ; Fischer, Normann
fYear :
2007
fDate :
27-29 March 2007
Firstpage :
467
Lastpage :
482
Abstract :
Transformer differential protection operates on Kirchhoff\´s well-known law that states, "the sum of currents entering and leaving a point is zero". Although Kirchhoff\´s law is well understood, the implementation of the law in transformer differential protection involves many practical considerations such as current transformer (CT) polarity, phase-angle correction, zero-sequence removal, and CT grounding. Still, even correctly implemented transformer differential protection misoperates occasionally, resulting from conditions such as CT saturation during heavy through faults. Whereas electromechanical and electronic relays provide no or very little fault information, numerical relays provide an abundance of information. However, the analyst must still select the correct fault information from this abundance of information to perform useful fault analysis. This paper demonstrates how to begin analysis of such events by using real-life oscillographic data and going through a step-by-step analysis of the relay algorithm using a mathematical relay model. Relay engineers can use this paper as a reference for analyzing transformer oscillography in a systematic and logical manner
Keywords :
current transformers; oscillographs; power transformer protection; relay protection; CT grounding; CT saturation; Kirchhoff´s law; current transformer; differential protection; electromechanical relays; electronic relays; mathematical relay model; numerical relays; oscillography; phase-angle correction; transformer fault analysis; Algorithm design and analysis; Circuit faults; Current transformers; Grounding; Information analysis; Kirchhoff´s Law; Performance analysis; Protection; Protective relaying; Relays;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Protective Relay Engineers, 2007. 60th Annual Conference for
Conference_Location :
College Station, TX
Print_ISBN :
1-4244-0994-2
Electronic_ISBN :
1-4244-0995-0
Type :
conf
DOI :
10.1109/CPRE.2007.359917
Filename :
4201112
Link To Document :
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