UHF PARTIAL DISCHARGE DIAGNOSIS OF PLUG-IN CABLE TERMINATIONS

The experiences in on-line application of the ultrawide band partial discharge (PD) detection in high voltage plug-in cable terminations are presented. Issues of sensitivity of capacitive and inductive field couplers (sensors) are discussed. A series of comparative tests was done using an artificial defect to establish a link between peak voltage, as well as the energy of UHF pulses and the corresponding apparent charge, provided with a conventional IEC 60270 method. Examples of the UHF phase resolved PD measurements and measurements with a power detector are given. Experiences from a field testing are reported as well. The diagnostic system can be applied as a quality check on the just assembled terminations, as well as for the purposes of the condition assessment of insulation integrity after years in service