Influence of the Commutation Current Frequency on the Vacuum DC Interruption

Interrupting frequency has a great influence on the breaking capacity of the breakers. In this paper, using the forced current zero method, vacuum DC interruptions were carried out in the synthetic test circuit under small current. The equipment for measuring the current was established, with which the post arc current and the chopping current were obtained. According to the results, the influence of high frequency current on DC interruption was investigated. The results indicated that the post arc current and the chopping current increased with commutation frequency. The commutation frequency and charging voltage influence the post arc current together. The chopping current reached 130A at 4.0kHz. High commutation frequency is disadvantageous for the DC interruption.