Analysis on Operational Improvement of OCR Using Voltage Component in a Power Distribution System for Application of SFCL

To protect the power systems from fault situations, the installations of protective equipment are inevitable and various types of protective devices have been installed in a power system. Overcurrent relays (OCRs), one of them, are basically used a lot in a power distribution system as a primary protective device. Recently, a rapid industrial development has made the power systems to be large. Accordingly, a fault current has been increased and a superconducting fault current limiter (SFCL), as a part of the countermeasure to reduce the fault current, has gotten a spotlight. Application of the SFCLs in the power system has abilities from the side of the fault current and ease voltage sag. However, this fault current reduction ability effects on the other protective equipment, like relaying, recloser and so on. Especially, in this paper, to reduce the effect on the trip operation of the OCR due to installation of the SFCL, the OCR using voltage component in a power distribution system has been suggested and the operational improvement of the proposed OCR has been analyzed through the PSCAD/EMTDC.