What are the Phenomena and Features of Surface Partial Discharge Evolution Triggered by Fixed Metallic Particles on GIS Insulator ?

Abstract: Phenomena and features of surface partial discharge evolution triggered by fixed metal particles on GIS insulator are studied in this paper. With application of incremental voltage, long-term tests are conducted on a set of 220kV GIS equipment platform to observe the entire process of surface partial discharge from its initiation to gradual development and the eventual occurrence of surface flashover. Features of surface PD phenomena at various stages are recorded in the form of trend diagram, scatter diagrams, two-dimensional histograms and gray-scale maps. Test results show that the phenomena of surface PD triggered by fixed metallic particles on GIS insulator indicates three developing stages from corona discharge domination to co-existence of corona discharge and surface streamer discharge, and finally, surface streamer discharge domination.
Key words: GIS, partial discharge (PD), fixed metal particles, insulator, surface discharge