Breakdown and Pre-Breakdown Phenomena in Water Under Impulse Voltage:Propagation of Positive Streamers

摘要

This paper presents investigations on streamerrninitiation and propagation in water under positive polarityrnimpulses up to 60kV. Experiments were carried out in arnpoint-plane geometry with gap distance from 10 to 60mmrn(breakdown measurements, streamer visualization,rncurrents, and emitted light). Different streamer types withrnvelocities from 10m/s up to 40km/s are evidenced over arnlarge voltage range. A negligible influence of electricalrnconductivity on streamer propagation is observed (fromrn10-1 to 25μS/cm). The comparison with streamerrnphenomena previously observed in non polar liquidsrnshows many similarities, but with much lower voltagesrnrequired to initiate and propagate streamers in water.