AC & DC Pollution Testing Methods: Accuracy & Limitations
Pollution performance of insulator strings is key in design of towers for overhead lines and even more pressing with silicone hydrophobic surfaces whose properties respond differently to various service conditions. This presentation summarizes relevant observations and test details when evaluating insulator strings under such conditions. It also explains why the testing of hydrophobic surfaces requires further work, as now underway in IEC, and why the issue of heavy and very heavy pollution conditions remains an open question. Finally, it seeks to demonstrate how DC glass insulators with appropriate shape can outperform the USCD expected from the IEC Guide.