Identification of Surface Discharges Over New and Aged Polymeric Chain Insulators Using a Non Invasive Method

Surface discharges generated over polymeric insulators installed in power equipment and transmission lines can eventually lead to failure, as damage over the surface of affected insulation can slowly evolve into severe faults. Thus, early detection of surface discharges can avoid an important disruption of the equipment. There are several methods for the early detection of surface discharges however most of them require decommissioning of the equipment. This paper briefly illustrates the differences in the emission of surface discharges between new and aged insulators using both radiated and conducted measurements in a High Voltage Laboratory. Test equipment including antennas as a mean of detection, and digital processing techniques for signal analysis, were used. This research is a basis for the early detection and identification of surface partial discharges in power substations and transmission lines. The measurement system has the advantage that no physical connection is required, allowing the electrical equipment to remain in continuous operation