On-Line Partial Discharge Diagnostics for Cable Terminations

Abstract: The experiences in on-line application of the ultrawide band partial discharge detection on high voltage cable terminations are presented. Issues of sensitivity, spatial selectivity and noise rejection for capacitive and inductive field couplers are discussed. A series of comparative tests was done to establish an interconnection between peak voltage, as well as the energy of UHF pulses and the corresponding apparent charge provided with a conventional IEC 60270 method. 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.