A METHOD OF SELECTING BETWEEN FAULTED AND HEALTHY CIRCUITS IN PARALLEL LINES USING ONE-END MEASUREMENTS

摘要

The present invention is concerned with a selection between faulted and healthy circuits in parallel lines, using one-end measurements in electric power lines, applicable to parallel power lines, fit for use in the power industry for overhead transmission lines. The subject of the inventive method using measurement of current signals at one end of the line in terminal A or in terminal B, processing measuring data, determination of pre-fault and fault current signals and the zero- sequence current signal, obtaining current phasors I A1 , I B1 , I C1 , I A2 , I B2 , I C2 , I 01 , I 02 , consists in that the method further comprises the steps of: -determination of a symmetrical scaling coefficient k prefault establishing a reciprocal relation between the currents of a single line of the parallel lines, - determination of the corrected fault current phasors after scaling and calculation of current differences sum for each line sdi1, sdi01, sdl2, sdi02, - determination of fault f 1 , f i01 , f 2 , f 02 coefficients, - determination of the value of flags ff1 and ff2 having a conventional value one or zero and a selection of faulted and healthy circuits in the parallel lines.