DocumentCode :
1766369
Title :
Comparative aging characteristics between a high oleic natural ester dielectric liquid and mineral oil
Author :
Singha, Santanu ; Asano, Roberto ; Frimpong, George ; Claiborne, C. Clair ; Cherry, Don
Author_Institution :
Corp. Res., ABB AB, Vasteras, Sweden
Volume :
21
Issue :
1
fYear :
2014
fDate :
41671
Firstpage :
149
Lastpage :
158
Abstract :
This paper presents a comparative evaluation of the aging characteristics between a high oleic natural ester dielectric liquid (HONE) and mineral oil based on an accelerated single-temperature thermal aging experiment at 150°C for a period of 3000 hours. The important physical (e.g., viscosity, moisture content, acidity) and dielectric (e.g., power factor, alternating current (AC) dielectric breakdown) properties of both the oils were measured and analyzed at different aging intervals. As expected, results show differences in aging behaviors between mineral oil and the natural ester liquid. The relative moisture content in HONE had stable and lower values during the aging duration as compared to the case of mineral oil, where the relative moisture content increased with the aging duration. Further, unlike the observations in mineral oil, the power factor (PF) and acidity of HONE increased drastically with increasing aging times. The most relevant observation made from this study was that in spite of this significant increase in the PF and acidity of HONE with aging, its AC dielectric breakdown voltage was quite stable, which is not observed in the case of mineral oil. This indicates that for natural ester liquids, higher values of PF (or dielectric dissipation factor) and/or acidity due to aging may not necessarily give a true picture on the dielectric performance of the ester. It is therefore important to note here that the threshold limits of some of the diagnostic parameters which are already established for mineral oil do not apply for ester liquids.
Keywords :
ageing; dielectric liquids; electric breakdown; power factor; power transformer insulation; transformer oil; AC dielectric breakdown voltage; HONE acidity; PF; accelerated single-temperature thermal aging; comparative aging characteristics; dielectric dissipation factor; dielectric properties; high oleic natural ester dielectric liquid; mineral oil; power factor; relative moisture content; temperature 150 degC; time 3000 hour; transformer oil; Aging; Dielectric liquids; Liquids; Minerals; Moisture; Oil insulation; Power transformer insulation; Natural ester; acidity; diagnostics; dielectric; insulating; moisture; power factor; thermal aging; transformer;
fLanguage :
English
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
Publisher :
ieee
ISSN :
1070-9878
Type :
jour
DOI :
10.1109/TDEI.2013.003713
Filename :
6740735
Link To Document :
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