Study On Adaptive Non-communication Protection For Transmission Line

Wavelet Analysis and Fuzzy theory considered as a burgeoning subject are appliedin many fields of power system,so much as in protective relay field. After analyzing thebasic application of Wavelet Analysis and Fuzzy in adaptive non-communicationprotection for power line, this paper presents a novel principle of trip acceleration, whichreaches to the end of the protected line in a multi-zone impedance protection, based onwavelet analysis. With the developed principle, the sensitivity of detecting the secondchange in the sequence currents is considerably improved. New trip acceleration isproposed based on fault analysis. This protection principle accelerates the â…¡zone ofdistance protection using the ratio of fault current component of non-faultphase. And a new scheme used in protection of double-circuit line isprotected based on fussy theory, correlation algorithm of the current ofcircuits fault-phase is used as the criterion.