A partial discharge data acquisition system based on programmable digital oscilloscopes

This paper describes a partial discharge measurement system based on a programmable digital oscilloscope. The system enables the acquisition of partial discharge data both on phase-resolved and time-resolved basis, thus allowing these two analyses. After the acquisition of partial discharge data, statistical operators are applied over the phase distributions, as a way to identify the type of defect present on the equipment under test and its corresponding degradation level. To check for the system performance and develop an initial database on partial discharges, it was used to measure partial discharges in air and solid insulation, and their main characteristics were determined. These measurements were carried out in a measurement cell developed with great care to prevent signal deterioration, allowing the registration of almost distortion-free PD pulses.