Defect detection and identification of sources in GIS based on laboratory and on-site experience

The most common defects in GIS apparatus are due to the presence of metallic particles, protrusions, as well as floating shields which originate mainly from imperfect manufacturing process, operation of switches, or may become trapped during assemble. The presence of defects deteriorates the insulation strength of a compressed SF/sub 6/ GIS apparatus and causes serious limitation in its practical application. These defects can be detected by several techniques, one of which is that using acoustic sensors placed on the enclosure. This paper reports on the defect detection and identification of sources in GIS apparatus using acoustic technique, based on laboratory and on-site experience. The tests give satisfactory result.