Measurement of Electrode Surface Temperature and Post-Arc Current in Vacuum Interrupter

In vacuum interrupters, plasma remains between the electrodes after the current zero due to arcs generated by the interruption of short-circuit current. This residual plasma affects the insulation recovery characteristics after current interruption. The post-arc current is a parameter that correlates with this ion density. It is also affected by the secondary electrons generated when the ions hit the high-temperature electrode. In this study, a prototype spiral electrode was mounted in a vacuum chamber, and the electrode surface temperature and the post-arc current were measured. The electrode was made of Cu-Cr material, and the interruption current of 10-24 kA was applied. The electrode surface temperature was measured two-dimensionally using a two-color pyrometer method. The results showed that the higher the electrode surface temperature, the higher the post-arc current and post-arc charge after current zero. (Abstract)