Title :
Transient charging for impulse surface flashover development in vacuum
Author :
Nakano, Yoshiaki ; Kojima, H. ; Tsuchiya, K. ; Hayakawa, Naoki
Author_Institution :
Nagoya Univ., Nagoya, Japan
fDate :
Sept. 28 2014-Oct. 3 2014
Abstract :
Surface discharge on solid insulator in vacuum is one of the significant issues in the development of vacuum circuit breakers and vacuum interrupters. By measuring induced current in electrostatic probes behind alumina dielectrics due to explosive electron emission (EEE) at surface flashover inception, we studied transiently formed charge characteristics on the alumina dielectrics in the development process of surface flashover. From experimental results, we found that EEE affects the flashover development through two effects of the transient charge: one is the suppression of the EEE current by the relaxation of the electric field below the cathode, the other is promotion of the secondary electron emission avalanche. In the latter effects, because of negative charge on the alumina dielectrics below the cathode, the secondary electron can fly longer along the alumina surface. As a result, the current channel on the alumina dielectrics is formed more easily.
Keywords :
alumina; flashover; secondary electron emission; surface discharges; Al2O3; alumina dielectrics; alumina surface; current channel; electric field relaxation; electrostatic probes; explosive electron emission current; impulse surface flashover development; induced current; negative charge; secondary electron emission avalanche; solid insulator; surface discharge; transient charge effects; transient charging; transiently formed charge characteristics; vacuum circuit breakers; vacuum interrupters; Anodes; Cathodes; Dielectrics; Electric fields; Flashover; Probes; Transient analysis;
Conference_Titel :
Discharges and Electrical Insulation in Vacuum (ISDEIV), 2014 International Symposium on
Conference_Location :
Mumbai
Print_ISBN :
978-1-4799-6750-6
DOI :
10.1109/DEIV.2014.6961618