Electrical performance of semiconducting glazed insulators under natural pollution in Thailand

Overhead lines supported by insulators are still widely used in different environmental conditions. In a polluted area the electrical performance of insulators will be degraded, which affects the reliability of the electrical power system. Such problems can be solved by utilizing semiconducting glazed insulators. This paper reports the results of experimental investigation on semiconducting glazed insulators in differently polluted areas namely, industrial chemical pollution, salt from sea and dust pollution. The investigation was carried out on small long rod insulators for 33 kV. The comparison of results are made between normal glaze and semiconducting glazed insulators. In addition under polluted conditions the performance of both porcelain insulators are compared with a silicone insulator. Investigation was conducted for two years. The results show that the semiconducting glazed insulator has flashover voltage about two times higher than that of normal glaze and also a little bit higher than that of the silicone insulator