Characteristic of Surface Partial Discharges Measured with Ultraviolet Camera

The performed research works consider diagnosis of different models of support and bushing insulators. Insulator systems undergo aging processes, which causes deterioration of the insulating properties. In addition, pollutants that accumulate on the surface of high voltage insulators cause further reduction of the insulation properties. Presence of pollutants and high humidity level cause formation of conductive paths, which acts as a source of partial discharges. Presented results depict optical signals, recorded by ultraviolet camera, which were emitted by surface partial discharges occurring on different insulator models. In particular, the effect of the relative value of camera sensitivity on the number of surface partial discharges counts was evaluated. In addition, analysis of the effect of the surface partial discharges generation time on registered counts number was made. The experiments were performed at a constant voltage of $0.9U_{p}$ and for a distance between the HV electrode and GND equal to 10 cm. The experimental study lasted over a period of 30 min, while the measurement steps were done every minute.