SU754560A1 - Device for cutting-out sectionalising separator in the mains with insulated neutral wire - Google Patents

Description

The invention relates to the field of electrical engineering and can be applied at substations with short circuits and separators.

A device for disconnecting the separator is known, which contains an intermediate relay, the winding of which is connected to the first capacitor through the contact of the current-free control relay through the short-circuit connector and the contact block of the latter. The contact of the intermediate relay in series with the winding of the shutdown electromagnet is connected to the second capacitor. Both capacitors are connected via diodes to the device power buses.

The disadvantages of this device is the lack of control of the current in the power line switched by the separator, and as a result, the possibility of the disconnecting of the damage by the current separator due to misalignment of the short-circuit blocker contact.

The closest in technical essence to the proposed device is a device containing a three-phase current relay, the disconnecting contact which sequentially with

a shorting contact is connected to the parallel winding of the intermediate relay and the first capacitor. The contact of the intermediate relay in series with the winding of the electromagnet off the separator is connected to the second capacitor. Both capacitors through t diodes are connected to the power source I.

The drawbacks of such a device are low reliability due to short-circuit block short-circuit block circuits having a considerable length and subject to interference, as well as the laboriousness of adjusting block contacts.

The aim of the invention is to improve the reliability of the device by eliminating the circuits of the short-circuit block contact and lower operating costs.

This is achieved by the fact that a known device for shutting down a sectioning separator installed in a network with an insulated neutral contains two current transformers connected in two-phase circuits, two discharge bridges, two diodes, two

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capacitor, three-phase current relay, first intermediate relay and separator disconnect electromagnet, while the outputs of the rectifier bridges are connected in parallel and connected to the device power supply buses and to the winding of the three-phase current relay, the first intermediate relay winding, the first capacitor through the first diode the second capacitor, in parallel with which through the closing contact of the first intermediate relay, is connected the winding of the tripping electromagnet, is additionally equipped with two acting as “current” relays, the closing contacts of which are connected in parallel and directly connected in series with a resistor and a capacitor, a second intermediate relay, a zener diode connected in parallel to the device supply buses, the secondary windings of current transformers connected to the rectifier bridge inputs through the windings of current relays, the winding of the first transformer < weft relay through a series-connected break and make contacts of a three-phase current relay, the second diode and the first resistor are connected to the second The second power bus, the winding of the second intermediate relay is connected between the first power bus and the connection point of the three-phase current relay contacts, the current relay and the closing contact of the second intermediate relay, the first capacitor, the current relay contacts are connected at one point and connected to the second power bus through a second resistor.

To improve the durability of the contact of the first intermediate relay, the coil of the shut-off electromagnet is connected to the second resistor ‘via the output of the amplifier with a common collector, the base circuit of which is connected via the first contact of the first intermediate relay to the first’ diode.

The drawing shows a diagram of the proposed device.

Current transformers 1 are included in two phases of a power line switched by a separator. The secondary windings of transformers 1 through the windings of current relays 2 are connected to the inputs of the rectifier bridges 3 connected in parallel with the rectified current side and connected to the device power buses. The latter are connected to a three-phase current relay 4 to monitor the presence of current in the line, Zener diode 5, designed to limit the voltage of the power supply bus, the first and second capacitors 6.7 energy storage devices to ensure operation of the device during dead time. The parallel-connected contacts 8 and 9 of the current relay 2 are connected in series with the winding of the second intermediate relay 10, the contacts 11 and 12 of which are connected to the capacitor 6 to reconnect it from charge to discharge through the relay winding 10. The winding of the relay 10 is connected through pin 13 of relay 4, diode 14 and a resistor 15 with a relay coil 4. The second pin 16 of the relay 4 is connected in series with the coil of the first intermediate relay 17, the pin 18 of which is connected to the base circuit of the transistor 19.

At the output of the latter is connected winding 20 of the electromagnet off the separator. Pins 8 and 9 are shunted by a chain of 21 s of a series-connected resistor and capacitor. Diode 22 separates the capacitor circuit 6 and 7. Resistors 23 and 25 are designed to limit the currents.

In emergency mode, when the current in the protected line reaches the actuation value of the current relays 2, the latter contacts 8 and 9 close the winding circuit of the relay 10, which is triggered and disconnects the capacitor 6 from the power bus and contacts 11 to it. After the switch is disconnected at the power end of the line, relay 4 will be kept in the actuated state due to the discharge current of capacitor 6 through pin 13, diode 14 and resistor 15, the value of which is selected from the condition of relay 4 returning faster than relay 10. Relay 4 delay On the return is provided for testing the line on the stability of damage with automatic restart (AR) on the switch of the power end of the line.

In case of unsuccessful reclosing, the voltage on the capacitor 6 decreases due to discharge to the voltage of the return relay 4. The latter returns and contacts 16 closes the winding circuit of the relay 17, which connects capacitor 7 through the resistor 24 to the base circuit of transistor 19 by contact 18 and the capacitor 7 is discharged through the winding of the electromagnet off the separator, which turns off the damaged section of the line. In case of successful AR, the relay 4 does not return due to the presence of the line current and the separator is not disconnected. Relay 10 returns in this case.

when the voltage drops on the capacitor 6, while its contacts 11 and 12 switch the capacitor 6 to the charge from the power bus.

Thus, the introduction to the known device of additional elements and the connections between them allows

stop using chains

blocking contact short circuit and increase the reliability of the device to turn off the separator, as well as reduce the cost of its operation.

Claims (2)

Claim 1. A device for disconnecting a sectioning separator installed in a network with an insulated neutral, containing two transformers such as two phases, two rectifier bridges, two diodes, two capacitors, a three-phase current relay, a first intermediate relay and a shut-off electromagnet, the outputs of the rectifier bridges are connected in parallel and connected to the device's power supply buses and to the winding, ke three-phase. current relay connected to the first bus one pole winding of the first intermediate relay, the first capacitor through the first diode second capacitor, in parallel to which through the closing contact of the first intermediate relay the electromagnet winding is disconnected in order to improve reliability by eliminating the block contact circuits shorting device and reducing operating costs, it is additionally equipped with two current relays, the closure contacts of which are connected in parallel and eauntied after ovatelno connected resistor and capacitor, the second intermediate relay Zener diode connected in parallel buses pi754560 '6 device, while the secondary ^4- nd current transformer windings connected to the inputs of rectifier bridges through the windings of current relays, the winding of the first intermediate relay 5 through the series-connected disconnecting and closing contacts of the three-phase current relay, the second diode and the first resistor connected to the second power bus, the winding of the second intermediate relay connected between the first power bus and the connection point the contacts of the three-phase current relay, the current relay and the closing contact of the second intermediate relay, the first capacitor, the contacts of the current relay are connected at one point and black of the second resistor connected to the second power supply bus. 2. The device according to claim 1, characterized in that, in order to increase the durability of the contact ί of the first intermediate relay, the coil of the shutdown electromagnet is connected to the second resistor through the output of the amplifier with a common collector, 25 which has a base circuit through the closing contact of the first intermediate relay attached to the first diode.