Dielectric characteristics of static shield for coil-end of gas-insulated transformer

Author

Inui, A. ; Inoue, T. ; Teranishi, T. ; Murase, H. ; Ohshima, I. ; Toda, K.

Author_Institution

Toshiba Corp., Tokyo, Japan

Volume

27

Issue

3

fYear

1992

fDate

6/1/1992 12:00:00 AM

Firstpage

572

Lastpage

577

Abstract

The impulse breakdown characteristics of insulation models simulating static shields for coil ends of SF₆ gas-insulated transformers are studied. The static shield is composed of a double-covered electrode and a filler between the coverings. If a filler made of elastomer material is fitted closely on the covered electrode to eliminate gas gaps between the filler and the covered electrode, the impulse breakdown voltage of the static shield is higher than with gas gaps. If a low-permittivity filler is used, the impulse breakdown voltage of the static shield is still higher. The breakdown voltage can be explained by considering that the breakdown is caused by small gas gaps between the filler and the covered electrode. The dielectric strength of the coil end can be increased by applying a static shield with an elastomer filler

Keywords

electric breakdown of gases; electric strength; gaseous insulation; high-voltage engineering; impulse testing; power transformers; sulphur compounds; transformer insulation; SF₆ gas insulation; coil ends; dielectric strength; double-covered electrode; elastomer; filler; gas-insulated transformer; impulse breakdown characteristics; insulation models; small gas gaps; static shields; Coils; Cooling; Dielectric breakdown; Dielectrics and electrical insulation; Electric breakdown; Electrodes; Gas insulation; Positron emission tomography; Power transformer insulation; Sheet materials;

fLanguage

English

Journal_Title

Electrical Insulation, IEEE Transactions on

Publisher

ieee

ISSN

0018-9367

Type

jour

DOI

10.1109/14.142721

Filename

142721