Detection Properties of Partial Discharge-emitted Electromagnetic Waves in Silicone Gels during the Electric Trees Development to Breakdown

In this study, the electromagnetic (EM) waves radiated by partial discharges from the electrode system placed in two types of silicone gels were measured with two different antennas with different bandwidths. The results showed that the EM waves radiated by partial discharge (PD) during electrical tree progression could be obtained in each gel, and that amplitude of the EM waves differed depending on the antenna type as well as the gel type. This result suggests that frequency bandwidth of the sensor or antenna should be selected to detect the EM waves radiated by PDs in gel insulator effectively.