Leakage current measurement of epoxy resin compound with silicon rubber

Currently polymer materials have been widely used in the distribution and transmission as electrical insulators such as epoxy resin. Several advantages of using epoxy resin as an insulating material are its low density, better dielectric properties, and epoxy resin has higher volume resistivity than that of the glass and porcelain. However, epoxy resin has some disadvantages when it is used in tropical areas concerning with the humidity factor, high ultraviolet radiation, acid rain and effects of contaminants. Consequently, insulator surface will be easily damaged due to electrical tracking, which is indicated by the surface tracking. Silicon rubber was added to improve the dielectric properties such as hydrophobicity angle. In this paper, the influence of silicon rubber compound on leakage current characteristic of epoxy resin samples has been investigated. The test was based on the method of Inclined Planed Tracking (IPT) IEC 587:1984 with NH4C1 as contaminants. The flow rate of contaminant was 0.3 ml/min. The 3.5 kV AC high voltage 50 Hz was applied to the top electrodes The experimental results showed that the leakage current characteristic was affected by filler treatment. The samples with the greatest hydrophobicity angle had longer time to have surface damage. This shows that it is more difficult for large hydrophobicity angle samples to have surface discharge.