A Novel Method for High Current Vacuum Arc Interruption Using Externally Applied Ultra High Axial Pulsed Magnetic Field

Axial Magnetic Field (AMF) is widely used in vacuum interrupters to keep the arc in the diffused mode. With increasing axial magnetic field, the multiple arc mode extends to higher arc currents. In this mode of arc, the fault current can be easily interrupted due to fast recovery of the diffused vacuum arc. The magnetic field amplitudes considered in the preceding studies are all less than hundreds of mT. In this paper, the interaction of the vacuum arcs with much more intense magnetic fields of several T are considered. For this purpose, the MHD equations describing the behavior of the high current vacuum arc are simulated in presence of a very intense pulsed magnetic field that is generated by a high current pulsed power source (Cascaded Flux Compression Generators), and imposed to the interruption chamber externally. It can be possible by using a current carrying inductor, which firmly surrounds the chamber. This helical inductor is placed as FCG load. The results indicate that FCG can multiply the seed current, i.e., fault current (150-kA) up to 1-MA and consequently generate magnetic flux density in order of 10 T interior of the chamber. According to the simulation results, in such a magnetic flux density, the high current vacuum arc (150-kA) can remain in diffused mode; this method can be applied to improve the interruption capability of vacuum interrupters.