4.3.6.2 Gas-insulated substations (GIS)
The criticality of GIS to electrical power generation/transmission has made it imperative
that PD activity within their enclosures is identified (see Chapter 2). Chemical
byproducts of SF6 (as used in GIS) are particularly active chemically and will readily
result in degradation within the system.
Due to their nature, and in particular the very high electric fields within their
assemblies, GIS suffer specific and relatively unique problems. These issues are
neatly summarised in a two-part series of papers [77, 78]. As indicated there, the