PROTECTIVE RELAYING APPARATUS FOR PROVIDING FAULT- RESISTANCE CORRECTION

摘要

23 49,578ABSTRACT OF THE DISCLOSUREProtective relay apparatus for providing acompensated fault impedance measurement for the determina-tion of a better estimate of fault location along a trans-mission line is disclosed. In an power system networkincluding local and remote generating sources disposed atrespective ends of a transmission line segment of thetransmission line, the protective relay apparatus isdisposed at the local end of the line segment to measurethe fault impedance for use in determining fault location.However, load flow conditions rendered by the generatingsources interact with a fault which contributes resistancesubstantially to the fault impedance of the transmissionline to cause an erroneous component in the fault impedancemeasurement rendering the determination of an erroneousfault location. The protective apparatus disclosed gener-ates a signal as a measure of this erroneous component andcompensates the fault impedance measurement as a functionof the erroneous component signal, a predetermined imped-ance characteristic of the transmission line segment, andthe fault impedance measurement to provide the compensatedfault impedance measurement.