SU1757005A1 - Device for automatic reclosing of electric power line - Google Patents

Abstract

Usage: automatic re-activation of the switch equipped with a drive. Summary of the invention: when the switch is disconnected from the relay protection, the contact of the switch 3 is closed, the contact of the switch 4 is closed and the square pulses, whose frequency is proportional to the frequency of the monitored network, begin to flow from the square pulse shaper 2 to the counting input of the time relay 7. After the set the number of pulses at the output of Q 1 time relay 7 appears 1, which through the logic element OR 8 starts the execution unit 10 and the switch is turned on. If the FPV fails, the time relay 7 continues counting and after passing the set number of pulses at its output Q 2, 1 appears, which re-opens the switch. In the case of a successful first or second PPV cycle, the time relay 7, via the logic element OR 13, clears the time relay 5 and returns the device to the initial state. 1 il. ate C XI ate XI

Description

fyw / ll. Manually

The invention relates to an emergency control device for a power supply network with a voltage of 0.4-35 "V. used for automatic restarting (ARC) of an equipped-drive circuit breaker.

There are known automatic reclosing devices that contain a time relay with a slipping contact, two-position relays, auxiliary switches of the switch, and a block of actuator contacts.

The disadvantage of such an automatic reclosing is that the first cycle of the automatic reclosing is carried out without a time delay, the time delay is not long enough and depends on the winding time delay during an operational shutdown. In addition, the use of such a device is possible only with switches equipped with a spring drive.

An AR device is known that contains two time relays of the first and second cycles, the reference capacitors, and the output element.

Such a device can be used with switches that are equipped with drives of any type, is completely blocked during operational shutdown.

The disadvantages of such a device are low moisture resistance due to the fact that the insulation resistance (actually about 1 MΩ) can be commensurate with the timing resistors. Therefore, in order to ensure high moisture resistance, it is necessary to use high-capacity capacitors (specific capacity more than 1 µF for 1s of exposure time), which dramatically increases the size of the device, since only low-leakage thermostable capacitors can be used as these capacitors

In addition, such a device has low accuracy due to technological variations in resistances and capacitances of timing components, temperature deviations, as well as exponential charging characteristics,

The closest in technical essence and the achieved result is a device for automatic re-activation of the power line, containing the Off button, two time relays, an execution unit, a blocking element and a power supply unit, a pulse converter, a coincidence element.

Such a device is distinguished by high accuracy, moisture resistance, small dimensions, which allows to provide high reliability, the possibility of

reliable information for the diagnostic control of the switch disconnection.

The disadvantage of such a device is that it implements only one cycle.

re-enable. The implementation of the second cycle is fundamentally impossible. In addition, a pulse shaper is turned on at the output of the power supply unit and pulses are fed through the switch contacts, which reduces the system noise immunity due to the switch contacts bounce, and also increases the reliability requirements of these contacts when transmitting low power signals. Bounce contacts on the initial

Stage 5 will necessarily cause an uncontrollable set of times.

The purpose of the invention is to improve the reliability of the power supply of the consumer, the accuracy of cycle shutter speeds and the introduction of

0 alarm on unsuccessful reclosing,

The goal is achieved by the fact that the device for automatic re-activation of the power line, equipped with a switch with a drive, contains a control key and a square pulse shaper connected to a source of supply voltage, a zero setting circuit, two time relays, made in the form of meters 0 pulses, the executive unit, the closing and opening auxiliary contacts of the switch, a third time relay additionally introduced, designed as a pulse counter, the second form tel pulses, the frequency of which is proportional to the frequency of control of the network, two logical elements OR, an alarm element. Moreover, the input of the first rectangular pulse former is connected

0 with the power supply source through the closing auxiliary contact of the switch, the input of the second rectangular pulse former through the disconnecting auxiliary contact of the switch, and the output of the first rectangular pulse former is connected to the counting input of the first and third time relay, the output of the second rectangular pulse is connected to account entry

This is an expensive time relay, the output of the first relay is connected to the setup input of the second time relay, the first and second outputs of which are connected respectively to the first and second inputs of the first logical element OR, the output of which is connected to the executive unit and the installation input of the third time relay, the third output of the second time relay is connected to the signal element, and the time relay output is connected with the second, the input of the second

an OR logic element, the first input of which is connected to the output of the zero setup circuit, and the output with the installation input of the first time relay, the setup zero input is connected to a control key that opens when the switch is manually turned on or off,

The introduction of new elements and connections will allow double reclosing, i.e. expand the functionality of the device compared to the prototype, while retaining its advantages over analogs, resulting from the use of digital pulse counting, the frequency of which is proportional to the frequency of the monitored network, and providing higher accuracy and moisture resistance compared to analogues.

In addition, the use of two pulse shapers connected through the auxiliary contacts of the switch directly to the monitored network, allows to avoid the influence of contact bounce, and, consequently, an uncontrollable set of time from the pulses generated when the contacts bounce. The introduction of a signal element connected to the third output of the second time switch allows the operating personnel to perform device diagnostics and its operation indicates a good automatic reclosing device and permanent damage to the line,

The drawing shows a functional diagram of the device for the automatic re-inclusion of the power line.

The device contains the first shaper 1 of rectangular pulses (FPI) and the second FPI 2, the pulse frequency at the output of which is proportional to the frequency of the monitored network. FPI 1 is connected to the power supply source through the opening auxiliary contact of the switch (VCB), FPI 2 - through the closing VCV 4, the first time relay (PB) and the third PB 6 are connected to the output of the FPI to the third PB 6. the counting input of the second PB 7, the Output PB 5 is connected to the setup input of the PB 7, the first and second outputs of which are connected respectively to the first and second inputs of the logic element 8 (LE) OR. The third output of the LE 7 is connected to the signal element 9 (SC). The output of the LE 8 OR is connected to the input of the execution unit (IB) 10 and to the installation input of the PB 6. The installation diagram (SU) zero is connected by its input to the source

supply voltage through a contact that is opened when the switch is manually turned on or off, the control key 12 (CU). To the output of KU 12 is connected

the first input of which is connected to the output of P86,

The device works as follows

After switching on the switch with the aid of KU 12 at the moment of time ta (Fig. 2, voltage diagrams) it closes VHB 3 and SU 11 with a short pulse of duration t through LE OR 13 sets O at the output of RV 5 and gives permission to read

5 times (chart 1). The PB 5, which is a pulse counter, starts counting the pulses coming from the output of the DRF 1 (fig. 2), and after passing the set number of pulses during

0 t at its output is set to logical 1, which prepares the reading of PB 7 (figure 4).

When the switch is disconnected from the relay protection at the moment of time tb, the VKV 3 is closed and VKV 4 is closed. The pulses from the output of the FPI 2 begin to flow to the counting input PB 7 {diag. 3). After the arrival of the set number of pulses, the output Q1 PB 7 {diag. 5) through time

0 and at time tc appears 1, which starts up through IB 8 OR OR. IB 10 turns on the switch and simultaneously the resolution for counting pulses is applied to PB 6. If the automatic reclosure is successful, the switch remains in the on position and the pulses coming from FPI 1 are counted by PB 6 during the time m.4 and at time td, logical 1 (diag. 6) is set, which will set the relay through LE OR 13

0 time PB 5 to its original state (O at the output), PB 5 will reset PB 7, which in turn will clear the time relay PB 6. After cleaning all time relays, the PB 5 will prepare for counting the pulses coming from

5 FPI 1. After passing a predetermined number of pulses through time t2, logical 1 will be set at its output and the automatic reclosing device will be ready for re-operation.

In case the inclusion after the first

0 cycle will fail, then the relay protection turns off the switch and the PB 7 continues to count the pulses coming from the DRF 2 After passing the set number of pulses at its output Q2

5, a logical unit appears that gives a command to the second AR. If the second recloser is successful, the device is reset as well as after the first reclose cycle. When the second reclosing fails, the PB7 continues counting

pulses and when the meter is completely filled, a T is set at its output, which turns on the signal element 9, indicating that both re-starts were unsuccessful, and also confirms the operation of the device.

The device is reset to initial state when the switch is manually turned on using the installation circuit 0. When the switch is manually turned off, all the counters (PB) are also cleared, so the automatic recloser does not occur, since for this the PB 5 must give permission for the reading of PB 6.

For effective operation of the device, the following condition must be met: the time delay of the time relay 6 must be longer than the time delay of the relay protection

 Max.

The device uses the principle of counting pulses, a frequency proportional to the frequency of the sinusoid of the monitored network, which makes it possible to increase the accuracy of the AR cycles and, therefore, to determine the switch of the line to be switched off remotely using network analyzers. In addition, counting circuits, in contrast to circuits made on the basis of timing capacitors, are characterized by higher moisture resistance and smaller dimensions. The device can be used as single or triple reclosing.

Claims (1)

Apparatus of the Invention A device for automatically restarting a transmission line equipped with a motorized switch, comprising a control key and a square pulse shaper connected to a power supply source, a zero setting circuit, two time relays made in the form of pulse counters, an execution unit, The closing and opening auxiliary contacts of the switch, characterized in that, in order to increase the reliability of the power supply of the consumer, the accuracy of the cycle time and signal timing unsuccessful automatic restart, it additionally introduces a third time relay, made in the form of a pulse counter, a second pulse shaper, whose frequency is proportional to the frequency of the monitored network, two logical elements OR, an alarm element, and the input of the first square pulse shaper is connected to the source the supply voltage through the closing auxiliary contact of the switch, the input of the second rectangular pulse former through the opening auxiliary a switch contact, and the output of the first square pulse generator is connected to the counting inputs of the first and third time relays, the output of the second square pulse generator is connected to the counting input of the second time relay, the output of the first time relay is connected to the setup input of the second time relay, the first and second outputs which is connected respectively to the first and second inputs of the first logical element OR, the output of which is connected to the executive unit and the installation input of the third time relay, the third The output of the second time relay is connected to the signal element, and the output of the third time relay is connected to the signal element, and the output of the third time relay is connected to the second input of the second OR logic element, the first input of which is connected to the output of the zero setting circuit, and the output to the setting input of the first the time relay, the input of the zero-setting circuit is connected to the self-rectifying contact of the control key, which opens when the switch is manually turned on or off by a switch.