Gas Insulated Substations have
become more frequent sites due to their reduced footprint
and high reliability of operation. But this reliability can be
undermined by the presence of free moving metallic particles
originating from breaker operations or mechanical vibrations.
These particles can generate high electric fields locally
initiating partial discharges (PD) within the insulation.
Repeated partial discharges will eventually produce a flashover
necessitating shutting down the GIS for repairs.
When partial discharges occur,
they generate electromagnetic waves that propagate throughout the
switchgear. GEs PDwatch monitors these waves in the pressurized
gas in the Ultra High Frequency (UHF) range. It is permanently
fitted, generates alarms and can be interrogated remotely at any
time so as to detect and eliminate emerging dielectric
faults.
