Analysis on Coordination of Over-Current Relay Using Voltage Component in a Power Distribution System With a SFCL

Abstract

To reduce the more increased fault current due to the increase of the power generation with the power demand, the superconducting fault current limiter (SFCL) has received attention as one of the effective methods to resolve the fault current problem. However, the operation of the protection device, especially dependent on the amplitude of the fault current, can be affected by the application of the SFCL. For the protection coordination between the SFCL and the over-current relay (OCR), one of the typical protection devices in the power distribution system, the resetting of operational parameters in the OCRs, which can be troublesome, is required. For these resetting's of the protection devices, the fault current calculation from the power distribution system considering the impedance of the SFCL is inevitable. In this paper, the method using the voltage component as the effective parameter of the OCR for the protection of the power distribution system with the SFCL was suggested. Through the analysis on the simulation results from the modeling of the OCR, the suggested method using the voltage component in the OCR could be confirmed to be more effective compared to the previous resetting method of the OCR.