Detection of GHz frequency components of partical discharge in various media

This paper concentrates on the characterization of high frequency radiation from Partial Discharge sources in dielectric materials. It is envisaged that identifying partial discharge radiation in this band could provide an advantageous detection solution, as interferers such as television and other common radio communication bands will not cloud the signal analysis. The experimental setup consists of a high voltage electrode in a point-to-plane excitation architecture. Three insulator materials are considered as the dielectric medium between the point and plane. A wideband double-ridged waveguide horn antenna located in close proximity to the partial discharge source is used as the partial discharge radiation sensor. The Power Spectral Density (PSD) is calculated and analyzed from 0 to 2.5 GHz. The influence of insulator geometry, dielectric properties, and imperfections (cavities/voids) on the resulting partial discharge radiation is under investigation. Results have shown that partial discharge generation in the material samples tested displays consistent PSD fluctuations in the frequency range between 300 MHz and 1.1 GHz.