NEGATIVE SEQUENCE CURRENT FILTER Russian patent published in 2018 - IPC G01R29/16 

FIELD: electrical equipment.

SUBSTANCE: invention relates to the electrical equipment, in particular to the electrical signal symmetrical components isolation devices, and can be used as part of three-phase AC systems with isolated neutral measuring, protection and alarm devices. Negative sequence current filter contains two toroidal cores, on each of which ballast resistor and a choke, located with the shift of 90° relative to each other the first, second, third and fourth primary windings are arranged, number of the first and fourth primary windings turns is twice as large as the second and third ones, the twelve-pulse rectifier connected to the toroidal cores first, second, third, fourth, fifth, sixth secondary windings, which connections form two six-phase systems having the spatial shift relative to each other for 60°, at that, the first, third and fifth secondary windings are located with the spatial shift of 120° relative to each other, and with the spatial shift of 30° relative to the second, fourth and sixth secondary windings, at that, the first toroidal core first secondary winding is connected to the second toroidal core first secondary winding, first toroidal core second secondary winding is connected to the second toroidal core second secondary winding, first toroidal core third secondary winding is connected to the second toroidal core third secondary winding, first toroidal core fourth secondary winding is connected to the second toroidal core fourth secondary winding, first toroidal core fifth secondary winding is connected to the second toroidal core fifth secondary winding, first toroidal core sixth secondary winding is connected to the second toroidal core sixth secondary winding.

EFFECT: technical result is increase in the relay protection reliability and accuracy.

1 cl, 1 dwg