Evaluation of degradation degree of artificially degraded silicone rubber surface

Polymer materials such as silicone rubber (SiR) have been used as housing material for insulators in distribution lines, however because polymer insulators are more expensive than porcelain insulators in Japan, their application is still limited. If their price can be reduced, there is potential for the installation of polymer insulators to accelerate. One way to reduce the cost is to improve the materials. Finding optimal alternative materials, requires grasping the extent to which such materials resist degradation during long-term use. In this study, we first propose a method for making degraded surfaces that resemble the surface characteristics of aged insulators. Additionally, we propose a method for evaluating the degree of surface degradation at which surface discharge (SD) is generated for a short time on the SiR surface. These two methods can contribute to the introduction of new materials for polymer insulators.