SHORT CIRCUIT CURRENTS LIMITATION DEVICE Russian patent published in 2018 - IPC H02H9/02 

FIELD: electrical equipment.

SUBSTANCE: short-circuit currents limiting device relates to the field of electrical equipment, it is intended for use in electrical networks with short-circuit currents exceeding the breakers tripping currents threshold values, and allows to increase the operation reliability, provided by its design simplicity. Device comprises transformer, made on the magnetic circuit (1) with non-magnetic gap and with dual-lead winding from the first (2) and second (3) aluminum foil wires isolated from each other by the dielectric films (4), wherein the first wire beginning (2, 9) and the second wire (3, 12) end form the series circuit comprising switch 5, the power supply load 6 and the power supply network (7), at that, the second wire (3) beginning and the first wire (2, 10) end are connected to the spark gap 8. First wire (2) beginning lead 9, the wire end (1) lead (10), the wire (3) beginning lead (11) and the wire (3) lead (12) end the define circuit with distributed parameters. In case of the short circuit with sharp decrease in the load (6) resistance, under the mains (7) voltage influence, flowing in the circuit containing the switch (5), the wires (2 and 3), dual-lead wound double-wound on the magnetic circuit (1), dielectric films (4), insulating from each other wires (2 and 3), load current sharply increases. Voltage at the device input significantly increases relative to the leads (9, 12). Considering that the output voltage, at the leads (10), (11), that is, the voltage across the spark gap (8), in 2⋅Q times greater than the input voltage, the spark gap (8) breakdown occurs, and it becomes closed. Spark gap (8) closing corresponds to the change in boundary conditions in the circuit with quasi-distributed parameters.

EFFECT: decrease in the spark gap (8) resistance leads to the sharp increase in the input and leads (9, 12) resistance.

1 cl, 3 dwg