DEVICE FOR DETECTING DAMAGED SECTION OF OVERHEAD ELECTRIC LINE WITH SUBBRANCES IN 6-35 kV DISTRIBUTION NETWORK Russian patent published in 2021 - IPC G01R31/08 

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering and power systems engineering and can be used to determine the location of damage in overhead electric lines with subbranches in the distribution network with a voltage of 6-35 kV. Essence is that the device for determining the damaged section of the overhead power transmission line with subbranches in the medium voltage distribution network contains in each of the phases of the overhead power transmission line with subbranches the current sensors and indicators of the subbranches, as well as means for radio communication with the receiver installed at the substation.The device contains a zero sequence voltage relay, a fault-phase selection detector, three “AND” elements, one “OR” element, two single-phase switches and a resistor. The zero sequence voltage relay input is connected to the zero sequence voltage output of the voltage transformer installed on the substation switchgear bus bars, whereas the output is connected to the first inputs of the first, second and third "AND" elements. The faulty phase selector inputs are connected to the secondary phase circuits of the voltage transformer installed on the switchgear bus bars of the substation. Outputs of phases A, B and C of the faulty phase selector are connected to the second inputs of the first, second and third elements of the “AND” element, respectively. The outputs of the first and second “AND” elements are connected to the first and second inputs of the “OR” element, respectively. The output of the "OR" element is connected to the controlled input of the first switch. The output of the third "AND" element is connected to the controlled input of the second switch. One of the inputs of the first switch is connected to phase C of the substation switchgear. One of the inputs of the second switch is connected to phase A of the substation switchgear. Other inputs of the first and second switches are combined and connected to the first input of the resistor.

The second input of the resistor is grounded.

EFFECT: increased reliability of operation due to the current input into the undamaged phase of the overhead electric line (OEL) with single phase-to-ground fault protection (SPGFP), sufficient to trigger the phase fault indicators.

1 cl, 1 dwg