UHF PD detection in GIS substations during on-site testing

This paper handles the experience with ultra high frequency (UHF) partial discharge (PD) detection during on-site testing of GIS. A typical PD monitoring system is described. The Cigre sensitivity verification for the UHF method is explained with reference to a test section of a GIS. Examples of PD events from on-site testing are given and discussed in terms of risk assessment. A new procedure for risk assessment of free moving particles by detection of PD bursts is introduced. During on-site testing the conditioning process on GIS can be made visible and evaluated with the help of UHF PD detection.