Influence of additives and hydrostatic pressure on streamers initiation and dielectric strength of liquids

This paper is aimed at the influence of additives and hydrostatic pressure on the initiation phase of streamers and the dielectric strength of liquids, in a point-plane electrode arrangement under dc voltages. We show that the increase of hydrostatic pressure and/or the addition of a certain concentration of an electronic scavenger compound as Iodobenzene or Carbon Tetrachloride increases the initiation voltage of streamers in liquids such as cyclohexane, silicon oil or tetra-ester. This results in an increase of the dielectric strength of these liquids. The fact that the streamer is accelerated in presence of such additives does not lead necessarily to the reduction of the dielectric strength of liquid.