Gas‐Insulated Switchgear (GIS)

Abstract

Gas‐insulated switchgear (GIS) is effectively used in dense urban areas or in other situations where high energy‐density is required but space for conventional outdoor air‐insulated switchgear substations is simply not available. This chapter concentrates on the particulars of partial discharge (PD) phenomena in GIS and GIL (gas‐insulated lines, a subset of GIS), with emphasis on the typical PD sources/defects found in GIS, the risk they present, and their PD signal behavior. Since a large portion of PD detection and especially PD monitoring is today done using radio‐frequency (RF) techniques, commonly and historically referred to as “the ultrahigh‐frequency method,” the RF signal environment presented by GIS will be covered along with typical signal processing techniques employed when using these methods. The chapter also touches on acoustic techniques, mainly used for locating PD sources, online PD monitoring, and the special considerations associated with high‐voltage DC GIS.