THE IMPULSE CHARACTERISTICS AND ELECTRIC STRENGTH OF VARISTORS PILES DEPEND ON GEOMETRY OF THE ELECTRODES


Abstract

The paper describes the results of the impulse characteristics and electric strength measurements of the pile of varistors with modified side surface. Basing on the impulse voltage tests on the surge arresters it was found that one of the reasons of the failures of these devices may be the surface discharge at the varistor - insulating housing phase boundary, through the gas between them. Flashover voltage of power protecting systems can be increase by applying of semi – conducting covers which will carry away the generated surface charge and uniform the distribution of electric field on material surface. Comparing two types of electrodes configuration on varistors, it was found that systems without gap between electrode and side surface of varistor exhibited higher values of withstanding voltage whether their side surfaces were covered or not covered with insulating or semiconducting layer.


Keywords

varistors; surface discharge; electric strength; flashover voltage

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Published : 2014-09-26


Kogut, K., Kasprzyk, K., & Zboromirska-Wnukiewicz, B. (2014). THE IMPULSE CHARACTERISTICS AND ELECTRIC STRENGTH OF VARISTORS PILES DEPEND ON GEOMETRY OF THE ELECTRODES . Informatyka, Automatyka, Pomiary W Gospodarce I Ochronie Środowiska, 4(3), 6-9. https://doi.org/10.5604/20830157.1121330

Krzysztof Kogut  k.kogut@iel.wroc.pl
Electrotechnical Institute, Division of Electrotechnology and Materials Science, Wrocław  Poland
Krzysztof Kasprzyk 
Electrotechnical Institute, Division of Electrotechnology and Materials Science, Wrocław  Poland
Beata Zboromirska-Wnukiewicz 
Electrotechnical Institute, Division of Electrotechnology and Materials Science, Wrocław  Poland