Electrical tree and deteriorated region in polyethylene

Author

Shimizu, N. ; Uchida, K. ; Rasikawan, S.

Author_Institution

Dept. of Electr. Eng., Nagoya Univ., Japan

Volume

27

Issue

3

fYear

1992

fDate

6/1/1992 12:00:00 AM

Firstpage

513

Lastpage

518

Abstract

In polyethylene subjected to high electric fields, a deteriorated region is formed before tree initiation. The chemical analysis of the deteriorated region by FT-IR and Raman spectroscopy showed that it contains excess carbonyl groups (C=O) and double bonds (C=C) compared to normal polyethylene. Scanning electron microscope observation found in the deteriorated region a number of voids with diameter <0.5 μm. The observation by transmission electron microscope revealed that the lamellar structure of polyethylene is destroyed in the deteriorated region. It was found that tree initiation voltages for AC ramp and positive impulse are increased after the formation of the deteriorated region. The change of polyethylene structure is considered to be responsible for the increase of treeing resistance. It is worth noticing that the formation of the deteriorated region has a possibility as a new way for voltage hardening of practical apparatus

Keywords

bonds (chemical); dielectric properties of solids; electric breakdown of solids; organic insulating materials; polymer structure; polymers; scanning electron microscope examination of materials; spectrochemical analysis; transmission electron microscope examination of materials; voids (solid); FTIR spectra; Raman spectroscopy; SEM; TEM; chemical analysis; deteriorated region; double bonds; excess carbonyl groups; high electric fields; lamellar structure; polyethylene; tree initiation voltages; treeing resistance; voids; voltage hardening; Chemical analysis; Electrodes; Erbium; Helium; Low voltage; Needles; Petrochemicals; Polyethylene; Scanning electron microscopy; Transmission electron microscopy;

fLanguage

English

Journal_Title

Electrical Insulation, IEEE Transactions on

Publisher

ieee

ISSN

0018-9367

Type

jour

DOI

10.1109/14.142714

Filename

142714