Analyse of Vacuum Arc Characteristics under Short-Circuit Breaking

Nowadays, the vacuum circuit breakers (VCBs) have been widely applied in the generator protective system and the medium voltage distribution and utilization power system. During the breaking process of the VCBs, the metal vapor arc plasma is inevitably generated and influences the dynamic and static insulation performance, dielectric recovery property and interrupting performance. In this paper, for analyzing the interaction of the electro-magnetic field with the metal vapor arc for the VCBs, three-dimensional magnetic field computation has been modeled and simulated for different contact structure, and the influence of the electrode contour on the axial magnetic field variation with the breaking process has been obtained and quantitively illustrated. Moreover, based on the comparison of different contact structure of AC VCB, the rational static and movable contact structure with magnetic field control scheme has been given out for improving the magnetic flow capability. And the corresponding vacuum arc test has been performed based on the established short-circuit current test system based on the IEC standard. During the vacuum arc experiment under the short-circuit current interrupting condition, intruding the experimental circuit, permanent magnet repulsion mechanism control system and high-speed image acquisition system into the whole system.