Adopting Spectral Analysis in Partial Discharge Fault Diagnosis of GIS With a Micro Built-in Optical Sensor

As partial discharge (PD) monitoring has become a significant means of insulation fault diagnosis, built-in UHF sensors is increasingly adopted in GIS. In this letter, we report a hypersensitive triple-band optical PD sensor which is combined to a UHF sensor with an existing flange assembled on GIS. By experiments performed on an 110 kV GIS chamber, it demonstrates that with the spectral information obtained by this novel optical sensor, the discharge severity evaluation and the multi-source discharge clustering can be realized without any signal strength and phase-resolves statistics, which has a practical significance for the fault diagnosis of HVDC equipment such as DC GIL and DC bushing.