METHOD FOR BUILDING REMOTE PROTECTION OF DOUBLE-END LINE AND DETECTION OF SHORT-CIRCUIT FAULT THEREIN Russian patent published in 2012 - IPC H02H3/08 G01R31/08 

FIELD: electricity.

SUBSTANCE: at each and of he line one measures currents and phase voltages and generates positive-sequence current and voltage that are used for determination of positive-sequence resistance from each end to the short-circuit fault (SCF) spot in the line from the expression: from the one end - from the opposite end - where Z_1B and z_1H - the determined positive-sequence resistances from the one and from the opposite ends , u_1B and u_1H generated positive-sequence voltages at the one and at the opposite ends, i_1B and i_1H - generated positive-sequence currents at the one and at the opposite ends, z_1L - positive-sequence resistance of the line protected. The obtained resistance values are compared with the given setting of resistance in excess of the line positive-sequence resistance. At occurrence of resistance values below the setting one identifies SCF in the line with such SCF location identified by such resistance values magnitude. When the setting is exceeded one identifies absence of SCF in the line.

EFFECT: reliability improvement alongside with method simplification.

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