Title :
Charging mechanisms of polymer spacers electrically stressed in SF 6 environment
Author :
Al-Najmawi, J.S. ; Farish, O. ; Fouracre, R.
Author_Institution :
Dept. of Electron. & Electr. Eng., Strathclyde Univ., Glasgow
Abstract :
An attempt is made to elucidate the mechanisms causing charge accumulation on and inside insulating spacers. The experiments were conducted inside a glass cruciform vessel which could be evacuated to 10 -2 torr and had a maximum SF6 working pressure of 2 bar. Cylindrical spacers of polytetrafluorethylene and polyethylene (diameter 20 mm, height 10 mm) were investigated. The charge accumulation on smooth-surfaced insulators was controlled by three mechanisms: dielectric polarization producing heterocharge, surface charge injection from the electrode, and bulk injection from the electrode. The charge accumulated was of the same polarity as the applied voltage. The rough-surfaced insulator produced charge distributions which had charge densities higher than those of the comparable smooth-surfaced insulator
Keywords :
dielectric polarisation; electric breakdown of solids; gaseous insulation; high field effects; organic insulating materials; polymers; static electrification; sulphur compounds; surface discharges; 10 kV; 10 mm; 10-2 torr; 2 bar; 20 mm; 30 kV; SF6 environment; bulk injection; charge accumulation; charge densities; charge distributions; charging mechanism; cylindrical spacers; dielectric polarization; glass cruciform vessel; insulating spacers; polyethylene; polymer spacers; polytetrafluorethylene; rough-surfaced insulator; smooth-surfaced insulators; surface charge injection; Dielectrics and electrical insulation; Electrodes; Glass; Plastic insulation; Polarization; Polyethylene; Polymers; Rough surfaces; Surface roughness; Voltage;
Conference_Titel :
Electrical Insulation and Dielectric Phenomena, 1992. Annual Report. Conference on
Conference_Location :
Victoria, BC
Print_ISBN :
0-7803-0565-5
DOI :
10.1109/CEIDP.1992.283231
