Surface charging of aluminas excited by impulse voltage in vacuum

Author

Kitani, M. ; Yamashina, T. ; Kobayashi, S. ; Saito, Y.

Author_Institution

Dept. of Electr. & Electron. Syst., Saitama Univ., Urawa, Japan

Volume

1

fYear

1998

fDate

17-21 Aug 1998

Firstpage

155

Abstract

An investigation was made of the charging properties of alumina insulators and the relation between the surface flashover properties and the surface condition. An electrode configuration composed of a needle electrode and a backside electrode, which formed an extremely nonuniform field, was used. Experimental investigation of the charging properties revealed that surface charging with positive voltage applications started at the anode triple junction and that surface charging formed by voltage application attenuated little with time. Surface analysis of the insulators before and after heat treatment and repetitive flashovers revealed that heat treatment at 150°C in vacuum reduced the oxides but could not remove the organic contaminants. However, after repetitive flashovers, the organic contaminants were removed from the alumina surface. Therefore, conditioning the alumina surface improves the flashover voltage as the number of flashovers accumulates

Keywords

alumina; electrodes; flashover; heat treatment; impulse testing; insulator testing; surface charging; vacuum breakdown; vacuum insulation; 150 C; Al₂O₃; alumina insulators; anode triple junction; backside electrode; charging properties; electrode configuration; heat treatment; impulse voltage; needle electrode; nonuniform field; organic contaminants removal; positive voltage application; repetitive flashovers; surface charging; surface condition; surface flashover properties; vacuum; Anodes; Electrodes; Flashover; Heat treatment; Insulation; Needles; Surface charging; Surface contamination; Surface treatment; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Discharges and Electrical Insulation in Vacuum, 1998. Proceedings ISDEIV. XVIIIth International Symposium on

Conference_Location

Eindhoven

ISSN

1093-2941

Print_ISBN

0-7803-3953-3

Type

conf

DOI

10.1109/DEIV.1998.740597

Filename

740597