An Adaptive Current Quick Break Protection Based on Power Frequency Variation

A mathematical model of resistance type superconducting fault current limiter (R-SFCL) is established and the influence to power frequency variation distance relay has been analyzed firstly. Then, it indicates that the input of the superconducting current limiter changes the circuit model before and after the fault, so that the power frequency variation impedance relay based on the pre fault memory data does not satisfy the superposition condition. An adaptive current quick break protection considering the impedance characteristics of superconducting current limiter is proposed, after the similarity and difference in principle and performance of the adaptive current quick break protection and power frequency variation impedance relay are discussed. Finally, the feasibility and effectiveness of the new method is verified by simulation in EMTDC/PSCAD.