The Influence of the Dielectric Effect on Discharge Sequence in Negative Discharge

The development of corona discharge in a needle-plate configuration is affected by several experimental parameters such as gap distance, tip radius, etc., but the influence of the dielectric effect was rarely mentioned. In this paper, both light radiation and the discharge current were measured under negative linear voltage. By adding an epoxy sample parallel to the needle-plate direction, the discharge sequence development of surface discharge is compared with the discharge sequence in corona discharge. Epoxy sample does not affect the initial discharge voltage, and both corona discharge and surface discharge present two stages in pulse sequence development. However, the accumulated negative charge on the epoxy sample inhibits the corona intensity at the same applied voltage and delays the transition voltage in the pulse sequence development. Moreover, the relation between the mean of current pulse magnitude and discharge frequency in surface discharge is coincident with that of corona discharge, demonstrating that epoxy has no effect on the development of continuous pulse pattern in the experimental setup.