Investigation of partial discharge distribution under different DC ramp speeds

This study investigates the occurrence and distribution of partial discharge during a ramped high-voltage DC test. The activation mechanism occurs within a layered polymer stack, situated between conductive cylindrical high-voltage electrodes. One of the layers contains circular apertures to simulate a gasfilled cavity. Analytical results for three independent voltage ramp rates revealed differences in partial discharge inception voltage, total count, and peak amplitude. A series of consecutive tests was conducted for each ramp rate setting to establish repeatability and generate probability distributions for the peak amplitude and time difference between discharge events. The probability distribution indicated the presence of outliers and a degree of non-Gaussian behavior in both the partial discharge amplitude and the time between events. It also demonstrated that the data appeared nonsymmetric and positively skewed, with variations observed among the ramp settings.