DocumentCode :
2926611
Title :
A method for the measurement of leakage current due to surface discharge at the oil-pressboard interface
Author :
Zainuddin, H. ; Mitchinson, P.M. ; Lewin, P.L.
Author_Institution :
Tony Davies High Voltage Lab., Univ. of Southampton, Southampton, UK
fYear :
2011
fDate :
5-8 June 2011
Firstpage :
41
Lastpage :
44
Abstract :
Surface tracking is the conducting path formed on the surface of an insulation material as a result of surface currents. Tracking has commonly been associated with solid insulation in air such as overhead line insulators but is now recognized to occur at the oil-pressboard insulation interface inside large transformers. The surface current is effectively the drift of charge under the action of an electric field which may be either the general electric field or a locally enhanced field developed around a space charge. A needle-bar configuration has been developed to promote surface tracking under controlled conditions at the oil-pressboard interface without surface flash-over or breakdown. This method is used to study the leakage current associated with surface discharge applied from a high voltage source on the oil-pressboard interface. This paper outlines the experimental set-up and presents results which compare the measured current against the corresponding partial discharges. Subsequently a mechanism describing the process by which leakage current is formed is proposed.
Keywords :
current transformers; electric current measurement; leakage currents; partial discharges; space charge; surface discharges; transformer oil; insulation material; leakage current measurement; needle-bar configuration; oil-pressboard insulation interface; overhead line insulator; partial discharge; space charge; surface breakdown; surface current; surface discharge; surface flashover; surface tracking; transformer; Current measurement; Discharges; Electrodes; Leakage current; Needles; Partial discharges; Surface discharges; surface discharge; transformers;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electrical Insulation Conference (EIC), 2011
Conference_Location :
Annapolis, MD
ISSN :
pending
Print_ISBN :
978-1-4577-0278-5
Electronic_ISBN :
pending
Type :
conf
DOI :
10.1109/EIC.2011.5996112
Filename :
5996112
Link To Document :
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