Electrical treeing properties of polyethylene degassed and impregnated with SF₆

authored by

H. K. Xie, M. Vester, Ernst Gockenbach, Manfred Beyer

Abstract

The electrical treeing properties of low-density polyethylene (LDPE) degassed and SF₆-impregnated have been studied for a needle-plane configuration. The experimental results show that the electrical treeing properties of LDPE can be improved by impregnating with SF₆, depending on the impregnating pressure and duration, i.e., the amount of SF₆ dissolved in LDPE, and improved more remarkably by degassing in a vacuum of 10^-6 bar for 170 h. Degassed and then SF₆-impregnated LDPE gives the best electrical treeing properties. On the basis of the results obtained, a model for tree inception and propagation of polyethylene in a divergent field is proposed which suggests that the tree initiation is due to the breakage of bonds of the polyethylene chain by injected high-energy charge carriers and the rapid reaction between energy-enriched singlet oxygen and polyethylene. Therefore, reducing the action of injected high energy electrons by impregnating with SF₆ and decreasing the concentration of oxygen in polyethylene can inhibit the initiation and the propagation of trees. The model is consistent with all the experimental results.

Organisation(s)

High Voltage Engineering and Asset Management Section (Schering Institute)

Type

Conference contribution

Pages

105-108

No. of pages

4

Publication date

1992

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Engineering(all)

Electronic version(s)

https://doi.org/10.1109/ICPADM.1991.172017 (Access: Closed)