Method and apparatus for limiting high current electrical faults in

Abstract

The present invention pertains to an electrical fault limiter. The fault limiter comprises a first magnetic core. There is also a second magnetic core opposing the first magnetic core. The fault limiter additionally comprises a third magnetic core adjacent the first magnetic core. Also, there is a fourth magnetic core opposing the third magnetic core and adjacent the second magnetic core. The electrical fault limiter also moreover comprises a rotor disposed between the first and second magnetic cores, and the third and fourth magnetic cores. The rotor is rotatable about a rotor axis. The first and second magnetic cores are disposed on a first side of the rotor axis and the third and fourth magnetic cores are disposed on a second side of the rotor axis. Each core has a first arm, a second arm and a body to which the first and second arms are connected. Each body has a superconducting bias coil disposed about it. Each arm has a conduction mode coil disposed about it. The rotor has a high magnetic reluctance sector and a return flux sector such that when the magnetomotive force from each superconducting bias coil balances with the magnetomotive force from associated load coils on an associated core, there is no force on the rotor. But, when the magnetomotive force from the superconducting bias coil is less than the magnetomotive force from associated load coils on the associated core, then a force is produced on the rotor causing it to accelerate and the reluctance of the primary magnetic circuit is decreased, thereby causing an increase in the self-inductance of the primary coil.