SU792455A1 - Device for protecting three-phase electric equipment from asymmetric modes - Google Patents

Description

ensuring protection of electrical installations with redundant power supply,

To achieve this goal, in the proposed device, there are sensors for controlling modes, made in the form of two antenna filters of zero sequence voltage, one of which is installed on the main, power buses of the protected installation, the outputs of which are connected to an actuator made in the form of two blocks , each of which contains a current bridge, to which are connected in series a thyratron, a resistor and a winding of a current relay, in parallel with which a capacitor is connected, two control circuits and, the first of which contains in series. the first closing contact of the current relay of the first block, the first closing contact of the current relay of the second block and the first output relay, the second control circuit contains the second closing contact of the second relay of the first block sequentially connected, the unit and the second output relay, the third closing contact of the current relay of the first block is connected in series to the circuit of the second unit thyratron, the second antenna filter The zero sequence is installed on the backup buses of the protected electrical installation, with an additional third thyratron connected in series with an additional resistor, the winding of the third current relay and the fourth closing contact of the current relay of the first block, in parallel with which an additional capacitor connected to the output of the first rectifier bridge, the first and second rectification bridges are interconnected by one end directly, the other through two opposite Secondary isolation diodes are connected, the second block is connected between the common connection point of the mentioned separation diodes and the common point of the rectifying bridges, the closing contact of the third current relay is connected in series to the first control circuit, the disconnect terminal. The tact of the third current relay is connected in series to the second control ...

Fig. 1 shows a functional diagram; Fig. 2 shows an electrical circuit of the executive body that explains the operation of the device for protection of redundant power lines from non-full-phase modes with automatic switching of the reserve.

The object of power supply 1 through switching devices, for example, switches 2 and 3 is powered by power lines 4, 5, one of which

is the main, and the other is the backup partitioning switch 6 located between these lines. Antenna filter zero-sequence voltage 7 is installed on line 4, the antenna filter zero-sequence voltage 8-on line 5, the outputs of the antenna filter zero-sequence voltage 7, 8 are connected to the input of the actuator U, The antenna filter zero-sequence voltage 7 is connected to rectifying bridge 10, the output of which includes a capacitor 11, in parallel with which are connected in series the closing contact 12 of relay 13, thyratron 14, resistor 15 and winding of current relay 16. Antenna f A zero-voltage voltage regulator 8 is connected to a rectifying bridge 17, the output of which includes a capacitor 18, Parallel to the capacitor 18 are connected in series the closing contact 19 of relay 13, thyratron 20, resistor 21 and winding of the current relay 22. Parallel to capacitors II and 18 are through separating Iody 23, 24 are connected in series connected resistor 25, capacitor 26 and series-connected thyratron 27, resistor 2B, winding of current relay 13. Closing contact 29 of relay 13 connected in series with lFl by touch

30 relay 16, with break contact

31 relay 22 with disconnecting coil

32 switch 2, the on coil 33 of the switch 3, the closing contact 34 of the relay 13, are connected in series with the closing contact 35 of the relay 22 and the closing contact 36 of the relay 16, with the turning off coil 37 of the switch 3 and the turning on coil 38 of the switch 2,

Claims (2)

The operation of the device. When an incomplete-phase mode of operation occurs, for example, on line 4 a signal is generated on the antenna filter of a voltage of zero sequence m, a capacitor 11 is charged through a rectifying bridge 10 and a capacitor 26 through a resistor 25 charges the trigger voltage of the thyratron 27, it is turned on and the capacitor 26 through the resistor 28 is discharged to the winding of the current-relay 13, contact-12 is closed and the capacitor 11 is discharged through the thyratron 14 to the winding of the current relay 16, P The contacts 29 of the relay 13 and 30 of the relay 16 in the opening coil circuit 32 are disconnected and the switch 2 is turned off, and the switch-on coil 33 turns on the switch 3 and the section switch 6. If a half-phase mode is present at the same time on line 5, the device will not work, because a zero-sequence voltage filter appears on the antenna filter 8 and after the rectifying bridge the capacitor 18 is charged, when the relay 13 is triggered, the contacts 19 are closed and the capacitance is discharged to the winding of the current relay 22, And. the circuit remains in its original state. In the case of power supply on line 5 and the appearance of an incomplete phase mode, a signal appears on the antenna filter of a zero-sequence voltage 8, which charges capacitors 18 and 26 through rectifying bridge 17. When the voltage on the capacitor 26 reaches the level of the thyratron 27 the last one is triggered and the capacitor 26 is discharged to the winding of the current relay 13, which is triggered, the contacts 19, 34, 12. fill up. The capacitor 18 times extends to the winding of the current relay 22, which closes the contacts 35, since living on the ondensator 11 is absent, relay 1 does not work and contacts 36 will stop with in the closed position. The closed contacts circuit 34, 35, 36 is energized by the opening coil 37 of the switch 3 and the switch coil 38 of the switch 2 and the oil switch 6. If there is a non-phase mode on line 4 at the same time, the device does not work, as the zero-voltage voltage antenna filter 7 and the capacitor 11 are charged through the rectifying bridge, when the relay 13 is triggered, the contacts 12 are closed, as a result, the capacitor 11 is discharged to the winding of the current relay 16, which contacts 36 open. power circuit coils Thus, the device performs a protection against non nofaznogo mode on each of the lines and the automatic source. The tests showed the high reliability of the device to protect redundant power lines from non-phase-phase modes with automatic switching of the reserve. The invention The device for protection of a three-phase electrical installation of alternating current against asymmetrical modes, contains mode control sensors made in the form of two antenna filters of zero-sequence voltage, one of which is installed on the main power supply buses of the protected electrical installation, the outputs of which are connected to the actuator, made in the form of two blocks, each of which contains a rectifying bridge, to which serially connected thyratron, resistor and current winding are connected The second relay, in parallel with which a capacitor is connected, has two control circuits, the first of which contains the first pin of the current relay of the first block connected in series, the first disconnecting contact of the current relay of the second block and the first output relay, and the second control circuit of the relay to be connected in series vts of the third block, the second closing contact of the current relay of the first block and the second output relay, the third closing contact of the current relay of the first block is connected in series to the chain of the said thyratron of the second unit, characterized in that, in order to expand the functionality of the device by providing protection of the electrical installation with backup power, the second antenna filter of zero sequence voltage is installed on the backup tires of the protected electrical installation, with the third thyratron connected in series with additional resistor, winding of the third current relay and the fourth closing contact of the current relay of the first block, parallel but with which an additional capacitor connected to the output of said first rectifying bridge is connected, the first and second rectifying bridges are interconnected to each other at one end, to the other through two oppositely connected isolation diodes, the second unit is connected between the common connection point of said separation diodes and about- the rectifier bridge, the contact of the third current relay is connected in series to the first control circuit, the opening contact of the third current relay is connected in series to the second control circuit. Sources of information taken into account during the examination 1. Gelfand Ya.S.Dolubev ML. and Tsarev M.I. Relay protection and electric on AC operational current. M., Energie, 1966, p. 235. 2. Selivakhin A.I., Slonov I.L., Saguzhdinov R.Sh. and Kuznetsov A.P. The device for zigicity from asymmetrical mode of operation of the section of a three-phase AC network with insulated neutral. For application number 2552532 / 24-07 1977. v-: ....-  f  79; 2455 X /.