Impact of corona on the long-term performance of nonceramic insulators

This work discusses with the impact of corona on the long-term performance of nonceramic insulators. The aging mechanism of insulating materials and the partial discharges measurement (PD) on insulating materials is also discussed. In this measurement the rise of surface temperature of some solid insulating materials during activity of corona in point-dielectric-plain electrode arrangement by means of noncontact infrared (IR) measuring system. As the method measures the mean temperature of the sample surface, it is important to keep the diameter of the measuring target, in a given electrode arrangement, as small as possible. The smallest spot diameter of the sensor was 2.5 mm. The measurements made in the same electrode arrangements but with another IR camera proved that the spot diameter is even smaller than 2.5 mm. It means that the actual surface temperature is higher than indicated one.