Dielectric Recovery Characteristics after High‐Frequency Current Interruption in Vacuum Circuit Breaker

Abstract

SUMMARY When the contacts of circuit breaker are opened just before current zero, the gap between contacts will still be very short. Therefore, it cannot withstand recovery voltage between the contacts. In such a case, multiple reignition is likely to take place. Many investigators had tried to clarify this phenomenon, and many reports have been published. However, high‐frequency current interruption and dielectric recovery characteristics are related to some parameters (value of current, arc time, and so on). In addition, arc phenomenon has also been implicated. Hence, it is difficult to understand this phenomenon accurately. In this paper, we conducted dielectric recovery test and high‐frequency current interruption test. Further, we conducted observation experiment using vacuum chamber in order to investigate the effect of small dc current. At the end, we calculated plasma density in the electrodes after high‐frequency current interruption by considering the result of observation experiment and dielectric recovery test.

A Hybrid DC Circuit Breaker Combining a Multilevel Converter and Mechanical Contactors: Verification of the Principles of Operation by Experiment and Simulation

“…After that, i CB drops to zero stepwise. This phenomenon is called "current chopping", being known to cause a switching charge in v CB [17,18]. As can be seen from Fig.…”

“…On the other hand, switching surge of VCB has to be properly suppressed to prevent re-ignition. It is reported that the switching surge can be suppressed by connecting an RC snubber circuit (CR surge suppressor) in parallel to VCB [18]. Thus, we evaluate operating characteristics with and without RC snubber circuit.…”