SU1644292A1 - Device for deblocking automatic reclosure unit of circuit breaker on bus supply end - Google Patents

Abstract

The invention relates to electrical engineering, in particular to relay protection of a distribution network. The purpose of the invention is to increase the reliability of the device in operation by preventing the development of damage on tires. The goal is achieved by the addition of a power source and a control unit to the device. 1 hp ff, 2 ill.

Description

The invention relates to electrical engineering, in particular to distribution networks.

The aim of the invention is to improve the reliability of the device in operation by preventing the development of damage to the tires.

Fig, 1 shows a functional diagram of the device; Fig. 2 shows power supply and control unit diagrams.

The device comprises a voltage transformer 1, current sensors 2-5, current executive elements 6-9, a power supply unit 10 and a control unit 11.

Figure 1 also shows a power switch 12 on the supply side, current sensors 13, a maximum overcurrent protection unit 14, an automatic reclosing unit (AR) 15, buses 16, and load current switches 17-20.

The control unit 1t is made in the form of a two-winding relay 21, a break contact 22 and a make contact 23 and 24. The power supply unit 10 is made in the form of a rectifying bridge 25. a diode 26, a resistor 27 and a capacitor 28. In addition, the device contains the closing output contacts

29-32 current actuators 6-9, respectively, and the closing block-contact 33 switch 12.

The device works as follows.

In the normal mode of operation of the network, the power supply circuit of the AR unit 15 of the switch 12 is broken by the closing contacts 24 of the two-winding relay 21.

During a short circuit (KZ) on the buses 16 (point K1), none of the current actuators 6-9 does not work, the two-winding relay 21 does not come into operation and the power supply circuit of the AR 15 remains broken. Therefore, the switch 12 does not automatically turn on again.

In the event of a short circuit at one of the connections (for example, at point K2), the current executive element 6 is activated and via the closing contact 29 supplies power to the winding I of the two-winding relay 21. The latter, with its closing contact 24, ensures the closing of the power supply circuit of the AR 15 unit lock

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After automatic reclosing, the auxiliary contact 33 of the switch 12 is closed, power is supplied to the second winding of the relay 21 and it is returned to its original state. If the first automatic reclosure fails, the closing contact 29 is again activated, and then the circuit operates in the sequence described above, as a result, the blocking of the automatic reclosing unit 15 is released again.

If all the provided auto-reclosers failed (for example, due to the failure of the load circuit breaker of the damaged connection), after the last unsuccessful shutdown, the device returns to its initial state as a result of manually turning on the circuit breaker 12 after eliminating a stable short circuit.

The power strip 10 contains a rectifying bridge 25 and a capacitor 28 connected to it via diode 26. The purpose of the capacitor 28 is to provide the necessary voltage to operate the control unit 11. In normal mode, the capacitor 28 is charged during short circuits with a deep fit voltage guarantees The required (stable) voltage at the terminals of the first winding of the relay 21 and, since the capacitor tank is selected with a certain margin, it also provides power to the restraining circuit 21 of the relay 21 (after ARA) and returns it to its original state.

Claims (2)

1. A device for unlocking a block of an av; automatic re-opening of a switch on the busbar power side, comprising a voltage transformer, designed to be connected on the supply side, current sensors designed to be installed at the outgoing connections to the output terminals of each a current sensor is connected to the input of the current actuator, characterized in that, in order to improve reliability by preventing the development of damage on the tires, a power supply and a control unit are added, and the outputs of all current actuators are combined and connected to the first input of the unit control, the second input of which is connected via the power supply unit with the output winding of the voltage transformer, the third input and the output of the control unit are designed to be connected respectively to the output and input of the automatic reclosing unit. 2. The device according to claim 1, that is, so that the control unit is made in the form of a dzukobmotechny relay with disconnecting and two closing contacts, while the sequentially connected disconnecting contact and the first winding of the relay are connected between the combined outputs current actuators and the first output terminal of the power supply unit, to the second output output of which are connected in series the second winding of the relay and the first closing contact, the second output of which is intended to be connected to the closing unit on the power switch, The second closing contact of the relay is designed to be connected to the input terminals of the auto-reclosing unit. Phie.1