Breakdown strength of synthetic solid dielectrics immersed in high pressure gaseous mediums and subjected to direct voltages

The breakdown characteristics of synthetic solid dielectrics immersed in CCl₂F₂ and mixtures of CCl₂F₂ and N₂ and subjected to bath positive and negative direct voltages with ripple contents are reported. The peak breakdown voltage of the solid dielectric immersed in the gaseous medium decreases with increasing ripple content as well as pressure of the medium. In gaseous mixtures of CCl₂F₂ and N₂ the peak breakdown voltage at any ripple content increases with increase of N₂. The decrease in the breakdown voltage is attributed to the energy density of surface discharges.