Calculation of High-Frequency Current Interruption in Vacuum Switch

Abstract

High-frequency current interruption caused by chattering of electrodes in a vacuum switch is calculated by a Mayr type macroscopic arc equation. Measured and calculated arc voltage and current are in good agreement, except for spike voltage escalations at current zero, under conditions of 75k, 100k, 120k and 200kHz resonance frequency of a L-C circuit parallel to the vacuum switch. Similar result is obtained in a case of 171kHz resonance frequency of a L-C circuit with a 1.0Ω dumping resistance. It is concluded that the use of the macroscopic arc equation is effective for calculation of arc voltage and current in vacuum switches.