While insulators account for less than 10% of the total cost of new overhead lines and substations, the potential consequences of their improper selection and poor performance are estimated to account for up to 60% of the Life Cycle Cost of these installations. In addition, insulator failures are the most frequent cause of costly unplanned system outages.
Similarly, it has been widely documented that many factors other than creepage distance and axial length influence insulator performance under polluted conditions. These include insulator material, shed diameter and profile, orientation with regard to direction of the main source of pollution and mounting angle – whether horizontal, vertical or inclined. All play a determining role in external insulation field and notably influence pollution flashover performance.
It is also widely recognized that no existing standard will simulate natural pollution and its diversity from location to location using one test in a laboratory simulation. Unforeseen elements at the site can still lead to insulator failure or flashover.
Naturally energized test stations are used by researchers and power utilities as a tool to achieve results that are viewed as fully representative of a site, while also offering a platform to test new insulator geometries and materials. Moreover, such test stations are one of the most cost-effective monitoring techniques to assess service performance of insulators under natural pollution conditions.
Attend the 2017 INMR WORLD CONGRESS in Barcelona-Sitges from November 5 to 8 to hear a paper by Ahmad Al-Thagafi who will present details of the Al Fadhili Pilot Insulator Test Station, used to support insulator selection and maintenance at the Gulf Cooperation Council Interconnection Authority.