Flow electrification characteristics of transformer oil by rotating electrode systems

Author

Jagadish, R. ; Poovamma, P.K.

Author_Institution

Central Power Res. Inst., Bangalore, India

Volume

10

Issue

3

fYear

1995

fDate

7/1/1995 12:00:00 AM

Firstpage

1326

Lastpage

1331

Abstract

Flow electrification has been found to be the principal cause of a number of failures of forced oil cooled power transformers. Flow charging characteristics of oil/cellulose system with factors like electrode configuration, electrode material, presence of Benzotiriazole (BTA), metallic contaminants and copper coils were investigated for paraffinic oil by employing a rotating electrode system. A few hydrodynamic parameters (viz. Reynolds number, boundary layer thickness and friction factor) were correlated with flow charging characteristics of oil for varying temperatures concentrations of BTA. With concentrations of BTA in oil (viz. 10 ppm and 25 ppm) a marginal reduction in flow charging of oil was noticed, but about 40% reduction was observed with 150 ppm of BTA. A significant reduction in the flow charging characteristics of untreated and BTA treated oils was also observed in the presence of copper coils and metallic particle contaminants

Keywords

electric breakdown; electrodes; electrohydrodynamics; friction; insulation testing; power transformer insulation; power transformer testing; static electrification; transformer oil; Benzotiriazole; Reynolds number; boundary layer thickness; electrode configuration; electrode material; failures; flow electrification characteristics; forced oil cooled power transformers; friction factor; hydrodynamic parameters; metallic contaminants; oil/cellulose system; transformer oil; Coils; Copper; Electrodes; Friction; Hydrodynamics; Inorganic materials; Oil insulation; Petroleum; Power transformers; Temperature;

fLanguage

English

Journal_Title

Power Delivery, IEEE Transactions on

Publisher

ieee

ISSN

0885-8977

Type

jour

DOI

10.1109/61.400912

Filename

400912