Influence of Voltage Distortion Shape on Partial Discharge Activity in Internal Voids

Electrical insulation materials, especially polymers, may contain miniature internal voids. Insulation systems created from such materials might hence suffer from the development of partial discharges in the voids. These discharges tend to erode the insulation material, which further increases their magnitude and quantity and leads to a significant enhancement of the degradation rate. Lately, due to the high number of power electronic components connected to the grid, repetitive high-frequency distortions occur in the parts of the network adjacent to these devices. Such distortions may cause the inception of partial discharge, which would usually not happen.This paper thus researches the effect of high-frequency voltage distortions on partial discharges in an artificially created internal void. Test samples containing the artificial voids were prepared by fused filament fabrication (FFF) method from PET-G material using a standard 3D printer. The employed FFF method of sample preparation achieved satisfactory precision in both the shape and size of the voids. The main observed parameters were oscillation waveform's frequency and its phase shift relative to the supply voltage. PRPD patterns were gathered for a variety of different setups, and the influence of both parameters was evaluated.