A unique sensitivity verification combined with real-time partial-discharge identification method

The sensitivity verification with the ultrahigh-frequency (UHF) method will be discussed in this paper. The sensitivity line with the UHF method based on the conventional (IEC 60270) one is different in the radial position of the defects inside gas-insulated substation (GIS), because transverse-electromagentic mode can be more weakened while transverse electric (TE)/transverse magnetic (TM) modes can be more enhanced as the defect comes close to the enclosure than the conductor. The result makes it difficult to detect the free particle with IEC 60270. A unique sensitivity verification, which is combined with real-time PD identification method, first enables us to identify the defects and thereafter to calibrate the apparent charge of each specified defect according to the sensitivity line.