Studies on the improvement of breakdown strength of polyolefins

Author

Niwa, T. ; Hatada, M. ; Miyata, H. ; Takahashi, T.

Author_Institution

Fujikura Ltd., Tokyo, Japan

Volume

28

Issue

1

fYear

1993

fDate

2/1/1993 12:00:00 AM

Firstpage

30

Lastpage

34

Abstract

Breakdown tests were conducted on a variety of polyethylenes and polypropylenes. High density polyethylene (HDPE) and polypropylene random copolymers (PPR) exhibited the highest breakdown strengths among the examined polyolefins. Model cables insulated with HDPE and PPR were manufactured, and the impulse breakdown strength of the HDPE cables made under some specific manufacturing conditions was 1.6×larger than that of conventional crosslinked polyethylene (XLPE). However, improvements were not observed in the impulse breakdown strength of PPR. The AC breakdown strength of HDPE and PPR cables also did not improve. The reason for the improvement in impulse breakdown strength of HDPE is the increased crystallinity of the insulating material, is brought about by the heat annealing applied to the cable in a manufacturing process

Keywords

annealing; cable insulation; electric breakdown of solids; electric strength; impulse testing; insulation testing; organic insulating materials; polymer blends; polymers; AC breakdown strength; HDPE cables; PPR; PPR cables; XLPE; breakdown test; crosslinked polyethylene; crystallinity; heat annealing; high density polyethylene; impulse breakdown strength; insulating material; manufacturing conditions; manufacturing process; model cable; polyolefins; polypropylene random copolymers; Breakdown voltage; Cable insulation; Crystallization; Dielectric materials; Dielectrics and electrical insulation; Electric breakdown; Electrodes; Insulation testing; Polyethylene; Polymers;

fLanguage

English

Journal_Title

Electrical Insulation, IEEE Transactions on

Publisher

ieee

ISSN

0018-9367

Type

jour

DOI

10.1109/14.192237

Filename

192237