Self-controlled pre-breakdown discharges in planar symmetry

Author

Altafim, Ruy A C ; Ferreira, G. F Leal ; Giacometti, Jose A.

Author_Institution

Inst. de Fisica de Sao Carlos, Sao Paulo Univ., Brazil

Volume

5

Issue

1

fYear

1998

fDate

2/1/1998 12:00:00 AM

Firstpage

77

Lastpage

81

Abstract

In measurements on Teflon FEP films charged in ⩽50 μm air gaps by microsecond impulse voltages, a uniform charge deposition on the films was observed. A regular increase of the film surface potential from a threshold value of the peak impulse voltage was found. However, for 300 μm air gap it was observed that abrupt charging occurs at a lower threshold voltage, indicating breakdown, and the charge deposition on the film becomes nonuniform. The behavior in air gaps <50 μm is explained here using Townsend´s theory of pre-discharges. It is shown how and why the interposed insulating film acts to make the system self-controlled, thus avoiding breakdown in the air gap, despite the large values of the applied peak impulse voltage

Keywords

Townsend discharge; air gaps; electric breakdown; insulating thin films; organic insulating materials; polymer films; surface potential; Teflon FEP film; Townsend pre-discharge; air gap; charge deposition; impulse voltage; insulating film; planar symmetry; self-controlled pre-breakdown discharge; surface potential; threshold voltage; Air gaps; Breakdown voltage; Charge measurement; Current measurement; Electric breakdown; Electric variables measurement; Electrodes; Electrostatic measurements; Surface discharges; Threshold voltage;

fLanguage

English

Journal_Title

Dielectrics and Electrical Insulation, IEEE Transactions on

Publisher

ieee

ISSN

1070-9878

Type

jour

DOI

10.1109/94.660774

Filename

660774