Abstract: GIS equipment has superior performance and less maintenance, and is widely used in main power grid with the voltage level of 220kV and above. Carrying out AC withstand voltage test for GIS is the last process to inspect the production and installation quality, so as to ensure the smooth operation of the equipment. This paper has introduced a case of partial discharge detection of 252kV GIS during AC withstand voltage test, analyzed the partial discharge detection and positioning process carried out during the test in detail, and verified the accuracy of the detection and positioning result through inspection and disassembly test by returning to the factory, which provides a certain reference for quality evaluation of GIS before putting into operation.

GIS; AC withstand voltage; partial discharge; detection