ABSTRACT

Ibrahim Abduh.  The Performance of Polymeric Materials for Isolators in High Voltage Application (supervised by Muhammad Arief and Salama Manjang).

This research project is a study on the performance of newly promoted polymeric materials – such as silicon rubber – as compared to the performance of conventional ceramic materials – such as porcelain or glass - when both used as isolators in high voltage application. The main feature of high voltage isolators made of polymeric materials is their hydrophobic characteristic.  

Laboratory experiments have shown that in clean air condition, the ceramic isolator has a surface contact angle of 45o, while the same test for the polymeric isolator yields a surface contact angle of 108o. This fact indicates that the ceramic isolators are hydrophilic, and the polymeric isolators are hydrophobic Even in polluted air condition, the surface contact angle of polymeric isolator is 75o which is very good as compared to the ceramic isolator’s only 0o. Electrical tests have shown that the surface leakage current of polymeric isolators is generally very small, i.e. 0.6 mA in dry and clean air condition, 0.77 mA in wet and clean air condition and 0.80 mA in wet and polluted air condition. The ceramic isolators have more than 3 times greater surface leakage current, i.e. 2.15 mA in dry and clean air condition, 2.52 mA in wet and clean air condition and 2.76 mA in wet and polluted air condition. Large surface leakage current of ceramic isolators is due to their hydrophilic characteristic that increases the surface conductivity. The hydrophobic characteristic of polymeric isolators, on the other hand, reduces the surface conductivity to limit the surface leakage current. 

. 

.