DEVICE FOR DISCONNECTION OF LINE WITH GROUND FAULT IN NETWORK WITH INSULATED NEUTRAL Russian patent published in 2020 - IPC H02H3/16 

FIELD: electric power engineering.

SUBSTANCE: use in the field of electric power engineering, currents, from which one or two lines are disconnected. Proposed device comprises power lines connected to substation buses via power line switches, alternating current source, between phase and zero wires of which each circuit breaker is connected: series-connected first closing limit switch of closing springs and motor of automatic motor gearbox; through "disconnect" switch of control switch to three positions with self-reset and through first closing auxiliary contact of power circuit breaker – shutoff solenoid; through series-connected: detachable jumper, emergency shutdown emergency contact, closing contact of automatic reclosure (ARC) time relay, the first indicating relay coil, the second closing limit switch of the closing springs, the second opening auxiliary contact of the power circuit breaker, the actuation solenoid; wherein between the zero wire and the connection point of the accident contact disconnection unit and the ARC time relay contact is connected a chain of series-connected ARC time relay coils and the third opening auxiliary contact of the power circuit breaker, and between the phase conductor and the point of connection of the first indicating relay coil with the second closing limit switch of the closing springs, the control switch "on" contact is connected to the three self-resetting positions, characterized in that a voltage transformer is connected to the buses of the substation, to the secondary winding of which connected to an open triangle, a voltage relay is connected to the closing and opening contacts, and to phase and zero wires of said alternating current source are connected first and second inputs of programmed time relay and inputs of single-phase double-wave diode bridge, first output of which through voltage relay closing contact is connected to third input of time programmable relay, in which fourth input is connected to second output of diode bridge, and to outputs of programmed time relay in control circuit of each power circuit breaker are connected in series connected charging resistance and connected to second output of diode bridge capacitor, parallel to which are connected in series connected threshold element and coil of intermediate relay, having first closing contact, shunting contact "disconnect" control key, and a second normally closed contact, which connects, via the voltage relay opening contact to the outputs of the diode bridge in the control circuit of each switch, the second indicating relay coil, breaking contacts of which are connected to the said chain from the ARC time relay coil and the third opening auxiliary contact of the power circuit breaker.

EFFECT: provision of automatic selection and disconnection of only line, on which there occurred a ground fault.

1 cl, 3 dwg