Severity diagnosis and assessment of the partial discharge provoked by protrusion in GIS

It is a common partial discharge phenomenon that is provoked by metal spikes on the surface of the high voltage bus bar of the GIS (Gas Insulated Switchgear). To measure the partial discharge based on UHF(Ultra High Frequency) under frequency voltage is also a very common field test project. In order to diagnose and assess the severity levels of the PD (partial discharge) provoked by metal spikes on the surface of the high voltage bus bar of the GIS, with the application of gradually increased voltage, long-term tests were conducted on a well-established 363 kV GIS experiment platform to observe the entire evolution process of PD from its very initiation till breakdown. And this paper also captures the PRPD and PRPS spectrograms during the tests from initial stage to breakdown stage. The results of this paper provide an effective rule to diagnose and assess the severity levels of the PD provoked by metal spikes on the surface of the high voltage bus bar of the GIS.