METHOD FOR DETERMINING INSTALLATION SITE FOR DEVICES FOR SECTIONALIZATION OF 380 V OVERHEAD LINE Russian patent published in 2017 - IPC H02H5/04 

FIELD: electrical engineering.

SUBSTANCE: invention can be applied to electrical engineering. Proposed method includes the following: calculating the minimum currents of the single-phase short circuit along the length of the overhead line considering the arc resistance at the fault location and “thermal decay” effect; constructing the graph depicting the changing value of the minimum current of the single-phase short circuit along the length of the section of the 380 V overhead line between the transformer substation and the location of the single-phase short circuit; selecting the nominal current of the fuse insert based on the offset from the working and peak currents of the electric load of the 380 V overhead line and setting it in the transformer substation at the beginning of the 380 V overhead line; calculating and constructing the graph depicting the relationship between the time of actuation of the selected fuse and the length of the 380 V overhead line voltage based on the nominal protective time-current characteristics of the selected fuse and the graph depicting the changing value of the minimum current of the single-phase short circuit of the length of the section of the 380 V overhead line voltage; determining the protected zone of the selected fuse based on this dependence, the fuse being installed in the transformer substation at the beginning of the 380 V overhead line voltage, in which the time of actuation is not more than 5 seconds; installing the sectionalizing fuse at the end of its protected zone, if the fuse installed at the beginning of the 380 V overhead line does not provide the protection of the entire line with the actuation time of not more than 5 seconds, wherein the rated current of the insert of the sectionalizing fuse is selected based on the offset from the working and peak load currents of the remaining section of the 380 V overhead line.

EFFECT: technical result is the reduced time of the actuation of the protection.

1 cl, 2 dwg