METHOD OF DIRECTED DIFFERENTIAL PROTECTION OF TWO THREE-PHASE PARALLEL LINES Russian patent published in 2018 - IPC H02H3/34 

FIELD: electrical engineering.

SUBSTANCE: field of application: electrical engineering. According to the method, currents of each of the phases of each of the parallel lines are converted in the current transformers, the geometrical summation of the phase currents of the first line is carried out with the shifted by 180° currents of the corresponding phases of the second line, the resultant three-phase sequence of currents is obtained, when the first and the second lines are asymmetric, the disconnection of the corresponding lines is achieved. Method is characterized by the fact that the matrix description of the current ratio of the two three-phase parallel lines is performed with the formation of current matrices based on the graph theory and on the double recording method, the operations on current matrices are implemented and the signaling signs of the functioning of differential protection are generated, the signal characteristics are determined by means of the combination of the results of operations on the current matrices, the issuance of the control signal ids carried out, when the faults of current transformers are detected, and the tripping of the lines and the issuance of the control signal in case of the faults detected by the current transformers are performed taking into account the signaling signs of the differential protection functioning.

EFFECT: technical result is the increase in the reliability of the directional differential protection of two three-phase parallel lines.

1 cl, 3 dwg