The dynamic voltage/current characteristics of vacuum arcs after breakdown at currents in the lower kHz-range

A test set-up is presented which is able to measure the arc voltage of vacuum interrupters after breakdown with currents in the lower kHz-range. Arc voltage measurements from this set-up are presented. The obtained dynamic voltage/current characteristics are discussed and compared to the known voltage current characteristic of a power frequency arc in vacuum. A simple vacuum arc model is presented describing the voltage current characteristic. The model is applied to assess the energy dissipation in the arc.