Moisture effects on the electric strength of oil/pressboard insulation used in power transformers

Author

Krause, Ch. ; Brupbacher, P. ; Fehlmann, A. ; Heinrich, B.

Author_Institution

WEIDMANN Transformerboard Syst., Rappersvvil, Switzerland

fYear

2005

Firstpage

369

Lastpage

372

Abstract

This paper reports and discusses test results from extensive laboratory work, investigating the impact of moisture of cellulose pressboard on the dielectric characteristics of surrounding transformer oil. The dielectric behavior at AC-voltage stress was investigated as a function of the water content of the samples. In particular, the interface oil/cellulose revealed pronounced effects. The partial discharge inception and the breakdown voltage are reported, and the statistical occurrence of the flashover paths is evaluated and discussed.

Keywords

dielectric materials; electric breakdown; electric strength; flashover; partial discharges; power transformer insulation; power transformer testing; statistical analysis; transformer oil; AC-voltage stress; cellulose pressboard; dielectric behavior; electric strength; flashover paths; moisture effects; oil-cellulose revealed pronounced effects; oil-pressboard insulation; partial discharge inception; statistical occurrence; transformer oil; voltage breakdown; Dielectrics and electrical insulation; Laboratories; Moisture; Oil insulation; Partial discharges; Petroleum; Power transformer insulation; Power transformers; Stress; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Dielectric Liquids, 2005. ICDL 2005. 2005 IEEE International Conference on

Print_ISBN

0-7803-8954-9

Type

conf

DOI

10.1109/ICDL.2005.1490102

Filename

1490102