Electromagnetic Design and Performance Analysis of a Flux-Coupling-Type SFCL

Abstract

Superconducting fault current limiter (SFCL) is an efficient way to solve the short-circuit problems in modern power systems. A flux-coupling-type SFCL (FC-SFCL) based on disconnecting coupling windings for current reduction has been developed in this study. FC-SFCL is considered as a potential scheme to limit fault currents due to its low steady impedance before fault and higher current-limiting impedance after fault. It contains a pair of high-temperature superconducting (HTS) coupling coils, wound on an iron core with air gaps. Raising the coupling coefficient of the HTS coils and reducing the loss are essential issues to improve its performance, which is mainly affected by the iron core structure and winding processes of HTS coils. In this study, the electromagnetic design of a 10 kV/500 A FC-SFCL one-phase prototype is completed based on a genetic algorithm, along with the performances of current-limiting capacity, response time, and loss of the prototype. The simulation results show the FC-SFCL prototype with electromagnetic parameters meets the design requirements, and has good performances in terms of current reduction and loss.