Switchgears represent the hubs of electrical energy grids. Gas-insulated switchgear (GIS) is a space-saving alternative to classic outdoor switchgear. The compressed gas (typically SF6) boasts significantly greater insulation strength than air and the distances to ground can be drastically smaller.
Switchgears are particularly important and maintenance-intensive components, since they comprise many moving parts. In many cases they remain standing still for several years, but in the event of a malfunction they have to reliably disconnect fault currents of many kiloamps within just a few milliseconds. Junction and transfer points of busbars and disconnectors are prone to error and therefore should be tested regularly.
The high voltage in switchgear creates stress for the materials being used in the equipment. Therefore, insulation tests are recommended. In principle, GIS systems require exactly the same tests as other systems. However, they are often difficult to access and this is why they require special solutions.
