Analyses of partial discharges in dielectric samples under DC excitation

Abstract

The main focus of the paper is to develop a better understanding of partial discharges under DC excitation. Partial discharges studied will initially be limited to discharges from well-defined discharge sites. These include corona, surface discharges and internal voids. The samples are first tested under AC excitation as a sense check to ensure the samples yield the expected PD events. The samples were then subjected to DC excitations where the PD events were recorded and subsequently analysed. A number of analysis techniques will be applied to potentially enable the identification and classification of the type of PD event occurring in the DC system under investigation

Partial discharge activity in polymeric cable insulation under high voltage AC and DC

“…Overall, results from the AC testing were as expected for a single void in LDPE insulation [14]- [18], [12]. This validates the test set-up and methodology and allows for knowledge generation under DC conditions.…”

Long term testing and analysis of dielectric samples under DC excitation

“…A ramp test method was used during DC PD testing on the dielectric sample. Previous work [9] has been conducted using the peak value of the AC inception voltage (VR) to determine three hold voltages for DC PD ramp testing. The three hold voltages are defined as VR/2, VR and 3VR/2.…”

“…This work builds on previous work detailing ramp testing of dielectric samples under DC conditions [9]- [10]. The ramp profile has been altered to reflect findings in previous work.…”