Proposed flux-based optimization method for determination of minimum superconductor material in shield-type superconducting fault current limiters

Distributed power generation and an ever growing load demand have caused the current levelof fault to exceed the nominal rating of power system devices, and fault current limiters are neededeven more. the superconducting fault current limiter, sfcl, forms an efficient category of currentlimiters. the superconductor part in sfcls is the most costly part of the device, and minimizing itsvolume, while maintaining the required characteristics of the device, would be very beneficial. in thiswork, using a simulated annealing optimization algorithm, a method has been proposed to determineminimum required bulk superconductor material in inductive shield-type sfcl structures. the flux linkagebalance, generated by the superconductor bulk and copper winding (being the base of the optimizationprocess), has been formulated versus dimensions. the optimum dimensions of the bulk superconductor ina model sfcl, having a limitation current of 3a, are determined using the proposed algorithm. a prototypehas been fabricated using determined dimensions, and is tested in an experimental circuit by applyingdifferent types of faults. these experimental results demonstrated satisfactory limiting characteristics ofthe fabricated sfcl. the optimum volume of the bulk superconductor material needed for fabrication oflarger scale sfcls has been calculated and compared with the volume of superconductors employed inworldwide sfcl projects.