A NEW APPROACH FOR OPEN AIR INSULATOR TEST STATIONS: EXPERIENCE FROM TALOS AND THE POLYDIAGNO PROJECT

Abstract

Insulator performance is strongly linked to local installation parameter such as the weather, induced stress, location, pollution etc. Therefore, insulator performance under actual service conditions is hard to be predicted based on laboratory tests, even though such tests may provide valuable hints and directions. Therefore, power utilities, especially these that have part of their network suffering from intense pollution problems, construct open air insulator testing stations in order to gain further insight on insulator performance. There, insulators are stressed under conditions that are as close as possible to the actual service conditions. The parameters usually monitored are the leakage current along with weather conditions. The Greek power, HEDNO, has gained significant experience from constructing and operating TALOS, its own open air test station in a heavily polluted location in the island of Crete. Recently, HEDNO and TALOS participated in a research project focused on the monitoring and diagnosis of polymer based outdoor insulators used in high voltage applications. This paper focuses mainly on the innovations implemented in the test station regarding to the monitoring scheme, set-up, hardware and software. These include adopting a variation of the usual leakage current monitoring set-up scheme, following a distributed approach for the DAS and using general purpose DAQs equipped with custom made Labview based software.