ZERO SEQUENCE CURRENT FILTER ON REED SWITCHES Russian patent published in 2023 - IPC H02H3/38 

FIELD: electrical engineering.

SUBSTANCE: invention related to the field of electrical engineering for the protection of electrical installations from single-phase short circuits. The zero-sequence current filter contains the first and second reed switches, a logic part connected to the contacts of the first reed switch, an actuator connected to the output of the logic part, the first and second windings wound on the first and second reed switches, respectively, the first amplifier connected to the second winding, the first phase-shifting scheme. According to the invention, the third and fourth reed switches are introduced into the filter. The contacts of the fourth reed switch are connected to the logical part. The third and fourth windings are wound on the third and fourth reed switches, respectively, and the second amplifier is connected to the third winding. The second phase-shift circuit is connected by the inputs to the outputs of the second amplifier, and by the outputs, through the second control resistor, to the fourth winding. The comparison unit is connected by inputs to the outputs of the first and fourth windings, and by the output - to the signaling unit.

EFFECT: increasing the reliability of the zero-sequence current filter on reed switches and expanding its functionality due to the timely detection of faults in its elements.

1 cl, 1 dwg