Operational experience on HVDC and HVAC insulators at Sylmar Converter Station

Sylmar Converter Station (SCS) personnel have used two methods to prevent insulator flashovers. The most widely used method was to coat the HVDC insulators with a room temperature vulcanized (RTV) silicone coating. Once the coating was applied, no further maintenance work was done. The second less widely used method at SCS was to install composite insulators consisting of silicone rubber sheds attached to a fiberglass core. Since silicone rubber sheds are water repellent, this property eliminates the need for another surface coating. This paper examines the operational performance of using both methods at SCS to prevent flashovers.