On the nature of prebreakdown emission currents in vacuum interrupters

Author

Pursch, H. ; Siemroth, P. ; Jüttner, B.

Author_Institution

Central Inst. of Electron Phys., Acad. of Sci., Berlin, East Germany

Volume

24

Issue

6

fYear

1989

fDate

12/1/1989 12:00:00 AM

Firstpage

917

Lastpage

920

Abstract

Characteristics of prebreakdown emission currents were studied for electrodes of CuCr before and after DC breakdown. The characteristics were analyzed by using the Fowler-Nordheim equation for field emission. Measurements were carried out with fresh electrodes and after various conditioning procedures. It was found that the value of the microscopic breakdown field strength E_b (calculated from the measured field amplification factor β) is reasonably constant for all surface conditions, with a value of (8.1±1.4)×10⁹ V/m. Therefore changes of the macroscopic breakdown voltage are obviously caused by different values of the field amplification factor. It was found that for all surface conditions investigated there exist well-defined correlations between the parameters β and S of the Fowler-Nordheim equation. The existence of this correlation and the constancy of the microscopic breakdown strength is regarded as an argument for the equality of the emitting points

Keywords

circuit breakers; electric breakdown; electron field emission; CuCr; DC breakdown; Fowler-Nordheim equation; conditioning procedures; field strength; macroscopic breakdown voltage; microscopic breakdown; prebreakdown emission currents; vacuum interrupters; Breakdown voltage; Electric breakdown; Electrodes; Equations; Helium; Interrupters; Microscopy; Shape; Surface cleaning; Vacuum breakdown;

fLanguage

English

Journal_Title

Electrical Insulation, IEEE Transactions on

Publisher

ieee

ISSN

0018-9367

Type

jour

DOI

10.1109/14.46311

Filename

46311