Experience of GIS condition diagnosis using partial discharge monitoring by UHF method

Partial discharge (PD) monitoring system by UHF method is suitable for internal condition diagnosis of gas-insulated switchgear (GIS) due to its high sensitivity.We have developed the UHF method diagnostic system, which uses the neural network. Through the experience of using PDM system, we have built confidence in its performance. The GIS condition diagnosis using PDM by UHF method is quite useful on site. This paper describes outline of our PDM system and also introduces some examples of our experiences during both factory test and on-site test with which we have ensured advance diagnoses for insulation reliability of GIS.