Axial magnetic field electrode is preferbility high-voltage vacuum circuit breaker

Vacuum circuit breakers are considered an attractive solution to climate change concerns regarding SF
₆
gas. From the beginning of vacuum circuit breaker, it was known that vacuum has the high arc extinguishing ability and insulation performances. At the time of the electrode, spiral electrode on contrate electrode is used, The contact materials were Bi on CuCr. There was a problem that was not able to be intercepted when the breaking current became 40 kA or more as the development of vacuum circuit breakers advanced. In the 1970s, vacuum circuit breaker was successfully interrupting from 12kV-200kA by the development of axial magnetic field (AMF) electrode. Research on AFM electrodes was carried out in laboratory.