Study on surface degradation of polymer insulating materials causedby leakage current

摘要

Some artificial aging tests were performed using test rods made ofSilicone Rubber (SR) and Ethylene Propylene Rubber (EPDM), based on theRotating Wheel Dip Test (RWDT) method and the Salt Fog Chamber Test(SFCT) method, and aspects of the surface degradation were evaluated.Following the tests, it was concluded that the surface degradation ofpolymer insulating materials is directly related to the partialdischarge and that measurement of the cumulative charge of the leakagecurrent is useful in evaluating the degradation. Moreover, an energizedexposure test using prototype composite insulators was carried out forfive years. The accelerating factor from the artificial aging test foractual use was estimated by comparing the amounts of cumulative chargein the artificial aging test and in the exposure test