Correlation between insulator surface and DC flashover characteristics in vacuum

Author

Sudarshan, T.S.

Author_Institution

Dept. of Electr. & Comput. Eng., South Carolina Univ., Columbia, SC, USA

fYear

1988

fDate

16-20 Oct 1988

Firstpage

53

Lastpage

59

Abstract

The high-voltage DC flashover characteristics of a large number of solid insulating materials were investigated. These materials included high-density aluminas from different manufacturers varying in bulk composition and surface microstructure, coated aluminas to reduce surface charging, steatite, and forsterite. The results show a strong correlation between the first and conditioned breakdown strengths, the rapidity of conditioning, and the surface microstructure. Specifically, it is shown that `generic alumina´ has widely varying voltage withstand strengths depending on the bulk composition, surface microstructure, and chemical surface state. Materials with a finely granular, closely packed structure exhibited the best voltage hold-off performance. Also, nonporous materials exhibit rapid conditioning to its final value

Keywords

alumina; flashover; high-voltage techniques; insulating materials; insulation testing; surface chemistry; surface structure; Al₂O₃; DC flashover characteristics; breakdown strengths; bulk composition; chemical surface state; coated aluminas; conditioning; high-density aluminas; insulator surface; nonporous materials; solid insulating materials; surface microstructure; Chemicals; Composite materials; Electric breakdown; Flashover; Insulation; Manufacturing; Microstructure; Solids; Surface charging; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Insulation and Dielectric Phenomena, 1988. Annual Report., Conference on

Conference_Location

Ottawa, Ont.

Type

conf

DOI

10.1109/CEIDP.1988.26308

Filename

26308