Title :
Failure of service aged 230 kV current transformers
Author :
McDermid, W. ; Black, T.
Author_Institution :
Manitoba Hydro, Winnipeg, MB, Canada
Abstract :
As of the spring of 2008 Manitoba Hydro had in service up to 39 current transformers rated 230 kV from a particular supplier. These had been manufactured in 1969, 1971 and 1975. Three failed explosively beginning in the summer of 2008. Dissolved gas-in-oil analysis revealed others with significant fault gas. As of the end of 2011 all remaining 230 kV current transformers of this type had been removed from service. The paper reviews the design, transport, service conditions and age which may have contributed to the high failure rate.
Keywords :
chemical analysis; current transformers; failure analysis; power transformer insulation; transformer oil; dissolved gas-in-oil analysis; failure analysis; fault gas; high failure rate; oil filled current transformers; service aged current transformer failure; voltage 230 kV; Circuit faults; Current transformers; Hair; Hydrogen; Nitrogen; Partial discharges; Windings; failure analysis; oil filled current transformers;
Conference_Titel :
Electrical Insulation (ISEI), Conference Record of the 2012 IEEE International Symposium on
Conference_Location :
San Juan, PR
Print_ISBN :
978-1-4673-0488-7
Electronic_ISBN :
1089-084X
DOI :
10.1109/ELINSL.2012.6251464
