An Accelerated Testing Framework for Assessing the DC Erosion Resistance of Silicone Rubber Composites

This paper studies the use of an accelerated and controllable testing framework to asses the DC erosion resistance of silicone rubber composites used for high voltage outdoor insulation applications. The framework examines the use of repeatable testing methods that generate controlled dry-band arcing under wet and dry conditions using a modified DC setup of the Comparative Tracking Index test and the AC dry-arc resistance test respectively. The composites are tested under the DC Inclined Plane Tracking-Erosion test with the outcomes used as reference for the composites' DC erosion resistance. With respect to the DC Inclined Plane test, the results indicate similar erosion resistance outcomes to the accelerated tests with a more distinct variance in the outcomes under the DC Comparative Tracking Index test. Moreover, a distinct pattern for the leakage current waveforms are observed amongst the composites under the DC Comparative Tracking Index test which correlates with the DC erosion resistance outcomes. The outcomes of the accelerated tests are repeatable, controllable and thus provide low uncertainty in the measurements for assessing the erosion resistance of silicone rubber. These observations could be utilized within the proposed accelerated framework to supplement the DC Inclined Plane Tracking-Erosion test in assessing the DC erosion resistance of silicone rubber composites for outdoor insulation applications.