Characteristics of high frequency interruption for vacuum DC breakers

摘要

Post arc current can reflect the residual plasma in the electrode gap and the zero zone characteristics, so it has a great influence on the interruption of the breakers. In this paper, a permanent magnet-repulsive force hybrid actuator is designed, and the post arc current measurement system is established. Based on the forced current zero method, a series of high frequency DC interruption experiments are carried out in the synthetic test circuit with vacuum interrupters. The influence of the commutation frequency and recovery voltage on the vacuum DC interruption is investigated. The results show that a short lag phase about 80 ns exists between the post arc current and recovery voltage. High commutation frequency leads to the rise of the post arc current, which is disadvantageous for the vacuum DC interruption. The post arc current also rises with the increase in the recovery voltage. The interruption is not just affected by the di/dt and du/dt. In this study, failing interruption at the first current zero happens when the transient recovery voltage is near 2800V. The current chopping occurs easily at high commutation frequency. And the chopping current value is proportional to the commutation frequency, which is up to 120A at 4.0 kHz. Published by AIP Publishing.