Propagation of streamer discharge in dielectric liquids with various molecular structure by using high-speed schlieren photography

Prebreakdown phenomena in a point-plane gap are observed in detail in dielectric liquids which have various chemical-molecular structure, especially turning our attention to chlorine atoms or fluorine atoms included in the molecular formula, when a 1.1/225/s impulse voltage is applied to a point electrode: Experiments are carried out by means of a high-speed schlieren photography consisting of a combination of an image converter camera and a horizontal type schlieren optical system, and simultaneously the prebreakdown current is measured by using a LED current measurement system set up at the side of the high-potential point electrode. As a result, the influence of chlorine atoms or fluorine atoms included in molecular formula and the point polarity on the streamer propagation is investigated and discussed