Theoretical considerations about partial discharge detection in distributed systems

Partial discharges are localised breakdowns at low strength material or at local field enhancement sites, and may lead to a progressive total breakdown. Within high voltage power equipment they may arise at voids, contamination, poor conductor profiles and floating metal-work. A partial discharge test is, therefore, a widely used quality control test. It will be shown by the analysis in this paper, that rather than being theoretically correct, the formula given is only intuitive and offers a grossly underestimated partial discharge magnitude in all realistic circumstances