SU995182A1 - Device for single phase automatic reconnection of three-phase power transmission line - Google Patents

Description

The invention relates to electrical engineering, in particular, to devices, relay protection and automation of power systems.

The main tasks in the implementation of single-phase automatic switching on (OAPV) transmission lines are the selection of the damaged phase in the event of a single-phase short call (short-circuit) on the protected line and the disconnection of the damaged phase from two sides, ensuring quick disconnection of the line by three phases during phase to . з. on hshnii, including when biphasic short-circuit. on the ground, as well as providing relay line protection in an incomplete phase mode and at the time of re-activation. These tasks are solved with the help of special organs of the organization of the UAPW, called the electoral authorities (IO).

A device for OAPV of a transmission line is known, which contains an IO unit consisting of six phase shift relays, each of which is supplied with a zero-sequence current. Phase currents of the reverse sequence of the line are also supplied to three of them, and linear voltages are hereinafter referred to hereinafter, unless there is a special reservation, by a phase shift relay is meant a relay with an operation zone close to 180 ° II.

The disadvantage of this device is incorrect action when disconnecting the damaged phase and. failure to protect the line in incomplete phase mode and during an automatic isolation circuit.

It is also known a device for

10 OAPV, transmission lines, IO in the KOTOR are made by means of six relays: three relays reacting to a phase shift between the currents of reverse and zero sequence, and three

15 remote type relays that react to the difference of phase currents and phase to phase voltage 2.

IO of this device provide line protection for interfacial circuits.

20 however, with single-phase short-circuit in incompletely Phase mode and at the time of the IOAD, they also work incorrectly.

The closest in technical essence to the present invention is a three-phase OAPV device for a three-phase transmission line, with high-speed relay protection and a current transformer (CTDT) and current measuring transformers equipped at each end, containing a disconnecting unit, the first the input and the first three outputs of which are intended for: connecting respectively to the output of the high-speed protection and to the disconnecting circuit of each phase of the line switch, and for each phase of the line a remote th electoral body (DIO).; responsive to the ratio of the phase voltage vector and phase current, compensated by the zero sequence current, three inputs of which are intended for connection, respectively, to the phase output of the voltage transformer, to the phase output and output of the zero j sequence of the CT, and the output is connected to the corresponding input of the disconnecting unit. At the same time, NOs can & JTb J equipped with a current blocking input on the phase that is disconnected in the OAPV cycle. This interlock includes a phase relay and a Delay on Response element and is controlled from the special output of the shutdown unit. This type of IO provides line protection in incomplete phase: mode and during OAPV Z. However, when the first single phase short circuit occurs. IO of a known device does not work very reliably, which leads to cascade tripping of short-circuit channels. those. to the fact that at one end of the DIO line the damaged phase is triggered only after this phase is turned off at the opposite end of the line. Such cascade trips are undesirable, as this triggers the short-circuit tripping. which leads to a large destruction of the wires in the KZ area, the time delay in the reserve trip circuit is increased. devices provided | (in case of failure of the EUT during single-phase short-circuit and two-phase short-circuit to earth), and the duration of possible overvoltages in the OAPV cycle is increased, which represents a great danger for overhead lines with a voltage of 750 kV. Thus, A disadvantage of the known device is the low reliability of operation due to the presence of cascade trips, the purpose of the invention is to increase the reliability of the device and exclude cascade trips. cottages equipped with high-speed relay protection and equipped at the cocked end izmaryatali TT and TN and switch with phase-phase drive, containing a disconnecting unit, the first input and the first three outputs of which are intended for i connection respectively to the output of the high-speed relay protection and to the breaking circuit of each phase .y are switched off, on the line, and on each line f a DIO that reacts to the ratio of the phase voltage vector and phase current vectors, the line compensated by the zero-sequence current, whose three inputs are are connected to the phase output of the voltage transformer, the phase output and the zero-sequence output of the TT, respectively, and the output is connected to the corresponding input of the disconnecting unit additionally equipped with a filter electoral authority (FULL) unit that reacts to the phase angle between the reverse and zero-sequence currents , four inputs of which are intended for connection respectively to the phase outputs and the output of the zero continuity of the TT line, the first second elements of the Delay, for operation, and for each phase line output unit name from; 9® and the first element OR, and the inputs of both elements of the response delay connected to the output Fixation command to turn off at least one phase of the shutdown unit, each phase output of the full name is connected to the first input of the output full name of the corresponding phase, the second and third inputs of which are connected. To the inverted outputs, respectively, per, ... th and second elements Delay on actuation, and the output - to the first :; the input of the first element OR of the same phase, the second input of Koioporo is connected to the output of the DIO of this phase, and you-; the stroke - with the corresponding input of the shutdown unit. In addition, each output unit name from the action may contain a second OR element and an AND element the output of the second element OR: s; is connected to the first input of the element I, the second and third inputs of which are connected respectively to the phase output of the unit, full name and inverse output g; the second element Delay on operation, the first inputs of the first and second elements are connected to the output OR, the second entrance to The second element OR is consistent with the inverse output of the first e element of the E-response to actuation. Fig. 1 shows a block diagram of the device; in fig. 2 is a block diagram of the output unit of PIL from operation; FIG. 1 shows a transmission line 1, equipped with a fast speed wiring protection 2, measuring CT 3 and TH 4 and a switch 5 with a phase control. Vzhok 6 outages, three DIO 7, blo, 8 FIAR first 9 and. second 10 elements Delay on operation of three blocks 11 for outputting the full name from the action and the first three elements OR 12 are part of the device 13. power lines. First entrance and tr

The output of disconnecting unit 6 is intended for connecting to the output of high-speed protection 2 and disconnecting circuits of circuit breaker 5. The inputs of DIO 7 and unit 8 of full name are intended for connection to phase. the outputs of TN 4 and TT 3, as well as to the output of the zero sequence TT 3. ..,.

For each phase output DIO 7.N-. indirectly, and the output of the same .phase of the block 8 of the full name through its block 11 of the output of the full name of the action is connected to the inputs of the first element OR 12, the output of which is connected to the corresponding input of the block 6 from the key. To the command of fixing the command to turn off at least one phase of the block b disconnect Connected to the inputs of the first 9 and second 10 elements Delay on operation, the inverse outputs of which are connected to the corresponding inputs of all three blocks 11 output of the full name.

- The output name unit 11 can contain the second element OR 14 and the element AND 15, the output of the second element OR 14 is connected to the first output of the element 15, the output of which, in turn, is connected to the first input of the second element OR 14 and from the second the input of the first element OR 12 of the corresponding phase. The second entry. the second element OR 14 and the element 15 are connected to the inverse outputs of the first 9 and second 10 ele fi nents, respectively; Delay and actuation; the third input of the element 15 is connected to the corresponding phase output of the block 8 of the full name.

The device works as follows.

In the initial position, the switch 5 is turned on with all three phases, there are no signals at the outputs of the protection and all elements of the device. An exception is the inverse outputs of aneNieHts 9 and 10 Delay on operation, on which there are signals, probably in (8) full name (with;; delay bases through the elements OR 12 on the inputs of block 6). However, since the components are zero and zero the sequence of the current line is missing, block 8 does not work. If, due to asymmetry caused by external short-circuits, block 8 is triggered, the disconnection of the switch 5 from block 6 will not occur until the protection 2 1 operates.

In the event of a single-phase kgz. on the protected line 1 cpa6ai% I, the 2n high-speed protection prepares the shutdown unit b for operation. The DIO 7 of the faulty phase and the block 8 of the full name are also triggered, on which the corresponding signal appears. Both at first and

On the second input of the element OR 12, a signal appears, from the first created element of them OR 12 triggers and sends a signal to the input of block 6 of the shutdown. The latter acts on the disconnection of the damaged phase switch and triggers elements 9 and 10 Delay on operation.

The time delay of the first element 9 Delay on operation is chosen with the greatest possible time difference between DIO and FIO with two-phase kGs. on the ground in the order of 20 msD. The time delay of the second element 10 Delay on operation is chosen longer than necessary to clearly form a command to turn off the switch 5 (about 50 ms;;

Tripping the first element 9

The delay to actuation leads to the fact that the output of block 8 of the full name, on which the signal does not appear, is blocked with the help of blocks 11, and the output corresponding to the pre-damaged phase,

not blocked. The operation of the second element 10 Delay on operation leads to the fact that all the outputs of block 8 of the full name using blocks 11 of the output of the full name are blocked to

return element 10 Delay on operation, to the initial position I.e. before returning to the initial position of the entire device after completion of the full cycle of operation.

Removing the full name from the action requires preventing the consequences of their possible malfunctioning after disconnecting the damaged phase of the line, at least on one side, at which the phase relationships between the currents of the reverse and zero sequences can adversely change. .In addition, in the event of a single-phase short-circuit fault. in the full-phase mode of operation, the full name lines have greater sensitivity, and a significantly lower dependence on the transient resistance at the short-circuit location than the DIO. Therefore, in the event of a short-circuit it is advisable to use a combination

DIO and full name, and in the incomplete phase peiiuiMe to at the time of OAPV - only DIO.

When a two-phase short circuit occurs, a high-speed relay protection of the line, two DIOs of the damaged phases and a full name on the intact phase are triggered, which leads to a quick and reliable disconnection of all three phases of the line. Since block b is disabled

contains a majority element, the inputs of which are connected to the outputs of the elements OR 12, in order to ensure that the three phases of the line are disconnected, it is enough to trigger the EUT on any two phases. After the first element 9 is triggered

and any of the EUT using blocks 11 of the name of the damaged phases are deactivated, and after the second element 10 is triggered. The response delay is the name of the intact phase.

In case of occurrence on the line of interphase short circuit. without a part of the earth, the j line is disconnected by three phases from the unit in disconnection in addition to the EUT. In this case, as a rule, the operation of relay protection and the failure of current organ or (and) zero-sequence line voltage are not shown. .

Thus, increasing the reliability of the device is achieved mainly due to the fact that with single-phase short-circuits. on the DNO line and. Name reserve each other srabaty-a. on the same phase, and when e} of a phase phase short-circuit. they reserve each other to the ground, - it works on different phases. .

In the proposed device when the occurrence short-circuit. The name and surname are used with the action directly on the phase disconnection, regardless of the type of zakykai on the ground.

Reliable operation of the electoral authorities allows us to exclude cascades in the deviation of both single-phase and high-phase short-circuits. to the ground, which is especially important on 750 kV lines, since the time of overvoltages at CZ is significantly reduced. Elimination of cascade disconnects reduces the dead time at CIA and the time of the short circuit itself. and, if available, the EUT of the EUT systems allows to significantly reduce the time delay in the redundancy chains (in the shutdown unit b) provided for the occurrence of the EUT in the case of short circuit with the participation of seg-shi.

Dao can be equipped with a current blocking input on the phase that is disconnected in the CIPS cycle. The proposed implementation (Fig. 2) Vloka. 11, the withdrawal of the name from the action provides the possibility of reliable operation and the action of the name in case of occurrence (the first short-circuit) and prevents the possibility of their wrong action in the last. Since in the initial position on the inverted outputs of the emitters 9 and 10, the delay in sending wave signals are present, when a signal appears at the output of block 6, the full name corresponding to the damaged phase, therefore, at the third input of the element 15 of block 11 of the same phase, the element AND 15 is triggered, it supplies the second input of the first: element OR 12 and the first input of the second element OR 14, after which its operation will not depend on the position of the first element 9 Delay

to trigger. After the second element 10 trips, the signal for triggering the signal from the output element I 15, i.e. from the output of block 11, the faulty phase disappears and no longer appears independently of the signals at the output of block 8 of the full name. The signals to the output of the full name of the intact phases will be blocked as soon as the first element 9 Delay

o to trigger.

The invention can be implemented using known elements produced by industry. Technical and economic efficiency of the invention is determined by the increase in the reliability of the device and transmission capacity due to the increase in speed when turning off the short circuit.

Q duration of overvoltages and reduction of the dead time due to the elimination of cascade short-circuit trips on the protected line.

The proposed device is advantageously used on high and ultra high voltage lines. It can also be applied on lines that are not equipped with measuring VTs, it is only necessary that the HPs be on tires to which

connected line.

Formula Invention

1. A device for single-phase automatic reclosing of a three-phase transmission line, equipped with high-speed relay protection and equipped at each end with measuring CT and voltage transformer and a phase-operated switch containing a disconnecting unit, the first input and the first three outputs of which are connected to the high-speed output respectively relay protection and disconnecting circuit of each phase of the line switch, and for each phase of the line DIO, reacting to the ratio of the phase voltage and phase vectors the current of the line compensated by the zero-sequence current, the three inputs to the high side are designed to be connected respectively to different output of the voltage transformer, to the phase output and output of the zero sequence of the current transformer, and the output is connected to the corresponding input of the disconnecting unit, to increase reliability and enable cascade outages, a block of full name is added to it, reacting to the phase shift angle between the currents of the reverse and zero sequence of the line, four inputs of which are intended for connection with respectively, to the phase 5 output outputs and the zero-sequence output of the current line transformers, the first and second elements of the Delay for operation, and for each phase of the line the output unit of the full name of the action and the first element OR, and the inputs of both elements Zg of the response to the operation are connected to the output of the command latch for disconnecting at least one phase of the disconnecting unit, each phase output of the full name unit is connected to the first input of the output unit of the full name of the corresponding phase, the second and third inputs of which are connected to the inverse outputs respectively This is the first and second elements, the second input of which is connected to the DIO output of this phase, and the output with the corresponding input of the disconnecting unit.

2. Device for and. 1, characterized by; that each output unit of the full name of the action contains a second element, OR, and an AND element, and the output of the second OR element is connected to the first input of the AND element,

the second AND third inputs of which are connected respectively to the phase output of the block name and inverse output of the second element Delay on operation, and the output is connected to the first inputs of the first and second elements OR, the second input of the second element OR is connected to the inverse output of the first element Delay for operation.

10 Sources of information

taken into account with expert

.one. Ermolenko V.M. Principles for the implementation of electoral authorities for phase-out in protection, and-g

15 sennye selective ability. On Sat Automation and telemechanics in electrical systems. M.-L., Gosenergoie. dates, 1959, p. 253.

2. Atabekov G.I. Theoretical

20 bases of relay protection of high-voltage networks. M.-L., Gosenergoiedat, 1957, p. 285-295.

3. Bogorad A.M., Nazarov Yu.G. Automatic reclosing

25 power systems. M., Enerta, 1969, p. 251-255.

- at

Claims (3)

Claim 1. A device for single-phase automatic restarting of a three-phase power line, equipped with high-speed relay protection and equipped at each 4Q end with measuring CTs and TH and a switch with a phase-by-phase drive, containing a trip unit, the first input and the first three outputs of which are intended to be connected to the output, respectively high-speed relay protection and tripping circuit of each phase of the line switch, and for each phase of the DIO line, responding to the ratio of the phase voltage and phase t the eye of a line compensated by a 5th zero-sequence current, the three inputs of which are intended to be connected respectively to the phase output of TH, to the phase output and output of the CT neutral sequence, and the output 55 is connected to the corresponding input of the trip unit, characterized in that, in order to increase reliability and exceptions for cascade trips, it additionally contains a block of full names that respond to the phase angle between the currents of the reverse and zero sequence of the line, the four inputs of which are designed to connect respectively fazde-retarded to you to exit and exit zero posledo9 995182 successive lines of the current transformers, the first and second elements triggering delay, and for each phase line output unit name of the action and the first OR gate, the inputs of the two delay elements The triggering. Batches are connected to the output. Fixing the command to turn off at least one phase of the shutdown unit, each phase output of the name block is connected to the first input of the name block of the name of the corresponding phase, the second and third inputs of which are connected to the inverse outputs of the first and second elements, respectively, Operation delay, and the output is to the first input of the first OR element of the same phase, the second input of which is connected to the DIO output of this phase, and the output to the corresponding input of the shutdown unit. 2. The device according to π. 1, characterized in that each full name output block from the action contains a second OR element and an AND element, the output of the second element or connected to the first input of the AND element, to the second third inputs of which the phase output of the full name block and the inverse output of the second element are connected, respectively to operate, and per5 is connected to the output outside the inputs of the first and second elements, or, the second input of the second element OR is connected to the inverse output of the first element Delay to operate. 10 Sources of information taken into account in the examination 1. Ermolenko V.M. The principles of the implementation of electoral bodies for phase-by-phase shutdown in protections 15 genuinely selective. On Sat Automation and telemechanics in electrical systems. M.-L., Gosenergoiz. dates, 1959, p. 253. 2. Atabekov G.I. Theoretical 2θ basics of relay protection of high-voltage networks. M.-L., Gosenergoediat, 1957, p. 285-295. 3. Bogorad A. M., Nazarov Yu.G. Auto re-enable in 25 power systems. M., Energy, 1969, p. 251-255. Fig.f Fig 2