PD measurements can be easily applied on GIS systems without the need of interrupting the operation. Such temporary online monitoring helps to identify internal imperfections of the insulation system, which may lead to breakdown and system failure in the future.
Due to the dielectric properties of the SF6 gas, partial discharge activity in gas insulated switchgear covers a bandwidth of well beyond 2 GHz. The mechanical properties of the components of gas insulated switchgear further allow transmission of such signals over a distance of a couple of meters. Thus, the partial discharge monitoring of GIS equipment is done preferably in the UHF range.
The GISmonitor is designed to suit all currently available UHF sensors for GIS PD monitoring. This includes embedded and external retrofit UHF sensors such as window sensors type WS and external flange sensor.
A special input protection unit (IPU2) blocks strong transients (VFT). The preprocessing unit FCU2 demodulates UHF signals into a lower frequency band for easy submission over longer distances.
Window sensors type WS
Input protection units (IPU2) & preprocessing units FCU2