The effect of electrical connection structures on the spectra of radiated partial discharge signals

Partial discharges (PD) generated in high-voltage equipment can lead to its complete destruction, as damage in external and internal insulation slowly evolves into severe faults. Thus, early detection of this condition is imperative. Recent developments in the application of radiometry to this area have shown how PD can be detected from the vicinity of energized equipment. Radiometric PD detection is advantageous to electric utilities since the high-voltage equipment need not be taken out of service and the measurement can be made from a safe area, without the need for any physical or electrical connection. This paper describes how the electrical connection arrangements influence the emission of radio frequency radiation generated by PD. The radio frequency response of a high-voltage test rig has been measured in order to compensate the received signal for the effect of the structure. The results show that compensated frequency response significantly differs from the uncompensated response.