Current limiting characteristic of saturated iron core SFCLs

Saturated Iron Core SFCL (SIC-SFCL) provides an attractive option for the suppression of fault current level in a high voltage or an extra-high capacity electric power network. Different from traditional devices, such as air core reactors, high resistance transformers, etc., the impedance of SIC-SFCL can change from very low in normal power transmission to very high for fault current limiting. The eventual value of the apparent impedance of an SIC-SFCL also varies with the magnitude of the fault current. Therefore, investigating the progressive properties in the current limiting process is key to fully understand the working mechanism and the performance of an SIC-SFCL. A computer simulation model of a 35kV SIC-SFCL was developed to study the limitation progression, and the results of these studies are presented and discussed in this paper.