Investigation on Vacuum Arc Dynamics and Discharge Transition Modes under Different Conditions

摘要

Arc dynamics and discharge mode transitions of vacuum arcs on Cu/Cr50/50 electrodes were investigated using high-speed camera technique in a wide parameter range. Current pulses with variable AC frequency of 25-100 Hz as well as pulsed DC currents with duration from 5 to 20 ms have been studied. The total charge transferred by the arc was kept constant through the variation of current amplitude. In addition, the influence of mean contact separation speed in the range of 0.3 up to 1.3 m/s was considered. The characteristics of the voltage recordings and optical imaging of the observed arcs indicate the conditions for the change between high-current anode modes. Optical and electrical characteristics of the arc as well as the existence diagrams of various modes are presented and discussed.