Study on surface deterioration of polymer insulating materials Investigation of hydrophobicity loss process of silicone rubber by Dynamic Drop Test

摘要

In comparison to porcelain insulators, silicone rubber is lightweight and has an advantage of hydrophobicity, it has excellent withstand performances under contaminated conditions. Therefore, it is expected to expand the use of it. CIGRE WG D1.14 aimed to establish new test procedure, Dynamic Drop Test. This test can evaluate the property of hydrophobicity loss of silicone rubber and is easy to install and handle. We studied the process of hydrophobicity loss in Dynamic Drop Test from three viewpoints. The first is the behavior and phenomena of water droplets on the surface when voltage is applied. The second is the leakage current. The third is the time variation of hydrophobicity. We measured contact angle to quantify the hydrophobicity by STRI method. Although we could not observe the change of hydrophobicity until first discharge occurred, the great reduction of the hydrophobicity was observed after first discharge occurred.