SU1065950A1 - Starting device of three-phase automatic reclosing unit - Google Patents

Abstract

THE DEVICE OF STARTING A THREE-PHASE AUTOMATIC REPEATED SWITCHING on the mismatch between the position of the control switch key and the switch of the transmission line, equipped with a transformer, voltage transformer, differential-phase protection, fast relay protection unit, fast-acting current relay unit, transformer, transformer, transformer, and fast relay. a linear switch that is connected between the linear switch and the current transformer through a series circuit of the control unit for the absence of voltage, block 3 of the current relay, the second output of which is connected through the backup relay protection unit to the input of the switch control unit, to which the first differential-phase protection output is also connected, to the first input of which the second output of the backup relay protection unit is connected, and the transformer to the second output line voltage, the second input of the backup protection unit and the first input of the control unit for the synchronization of the line voltages and buses adjacent to the power line and equipped with a voltage bus transformer connected between the output of the voltage absence control unit and the first output of the three-phase automatic reclosing unit, to the input of which the second output of the control unit of the switch is connected, and to the second output - the second input of the voltage-free control unit, to the third input of which the voltage transformer is connected , the third input of the voltage synchronization control unit is connected to the output of a bus voltage transformer, which is characterized by the fact that, in order to increase the efficiency of a three-phase automatic repeat switching on due to the line in operation in all cases of potentially successful three-phase automatic reclosing, it additionally contains four AND logical blocks, two time delay blocks, the second j OHTpojiR block has no line voltage, a line voltage control block and control connected between the inputs of the prohibition unit and the third output of the backup relay protection unit through the series-connected first logic block AND, the first block of time delay, the second logic block AND, second a third time block, a third logical block AND, and a third of its third logical block AND is connected to the second input, the second, the input of the first logical block AND, and the output of the second control unit for the absence of line voltage, whose input is connected to the output of the line voltage transformer that is connected through the control unit, the voltage across the line to the second input of the second logical block I, and. the fourth logical block AND is connected to the output of the first block of time delay, to the second input of the third logical block AND and to the third input of the differential-phase protection, the second output of which is switched to the second

Description

control key input, and the third output - to the third input of the first logical block, And, and the second output of the block

control switch is connected to the fourth input of the first logical block I.

The invention relates to electrical engineering, in particular, to relay protection and automation of electrical networks and systems, and is intended to increase the efficiency of three-phase automatic reclosing (TPV). The principle of operation of TAPV devices on a power transmission line (LEP) is well known. The principle is that TAPV devices with synchrocheck check are performed at one end of the line with no voltage control on the line and with synchronization control, and at the other end only with the presence control synchronism l. The disadvantage of this solution is the rigid sequence of switching the power line switches at its TAPV after short circuit, which means that the switch of one end of the line is always turned on first and the other one is second. At the same time, if the switch of one of the ends of the line for the first time turns off the short-circuit current, close to or even equal to the current of its breaking capacity, then the automatic re-activation of this circuit breaker on the non-eliminating short-circuit. the condition of his work during the second shutdown of the short circuit is significantly improved. Such an activation is possible, since the sequence of switching the line breakers during TAPV does not allow to vary the place of the first start of the automatic restarting (AR) of the line. Known technical solution for the launch of automatic re-inclusion of an element of the electrical system, including transmission lines. In general, power lines are equipped at each of their ends with current transformers in each phase and voltage transformers. On power lines with a voltage of 220, 500 kV and above, the main differential-phase protection and a backup relay protection system are installed. If there are power supply systems at the ends of the power lines, the TAPV devices of the linear switches are triggered by the mismatch between the position of the control key of the linear switch and the switch itself and control the absence of voltage on the power lines or synchronism of line voltages and busbars adjacent to the line through the linear switch. With increasing power-to-power systems, the level of short-circuit currents (short-circuit), switched off by linear switches, increases: and it can approach or even exceed the limit cut-off current normalized to the switch. It is proposed to measure the magnitude of the short-circuit current. in the circuit of a breaker of a damaged element, including power lines, compare it with a predetermined amount of current depending on the actual breaking capacity of the switch by the time the switch is turned on again. Current level measurement k.z. The circuit breaker is manufactured using a fast current relay 2. The disadvantage of this solution is an unambiguous rejection of the ARC line in these cases without taking into account the results of the process of deionization of the arc gap in the space of the short-circuit. when the voltage is removed from the line after it is disconnected. It is known that most k.z. on 110-500 kV power lines, they are self-destructing, therefore blocking of the automatic reclosing is off; the drive of one of the ends of the line prevents the line from being turned on again if the short circuit is removed. in auto reclose cycle. The purpose of the invention is to increase the efficiency of a TAPV by putting the line into operation in all cases of potentially successful TAPV. This goal is achieved by the fact that a three-phase automatic reclosing start-up device (TAPV) due to a mismatch between the position of the switch control key and the power line switch (TL) equipped at each of the ends with a current transformer (CT), a voltage transformer (TNL),. phase protection (DFZ), backup relay protection unit (RNS), high-speed current relay (BRT), containing the control unit of the linear switch (WEL) connected between the linear switch and the CT through a series the absence of a voltage absence control unit (BKON), an inhibit unit (BZ) and a high-speed current relay (ART), the second output of which is connected to the second output of a CCU through the BRRZ, which is connected to the first output of the DPS, and the second output of the BRRZ is connected to the first output ,

and to the second - TNTL, the second input of the SRRZ and the first input of the synchronism control unit for line and busbar voltage (BKR) adjacent to the power line and equipped with a voltage transformer connected between the BKON output and the first TAPV output, the input of which is the second output BOOV, and the second output - the second input of the BKON, the third input of which includes the TNL, the third input of the BCS is connected to the output of the TNSh, additionally contains four logical blocks AND (BI), two blocks of time delay (BV), the second control unit is absent for example line wiring (BKON), control unit the presence of voltage on the line (BKNN) and the control key (CU) connected between the inputs of the BZ and the third output of the SRRZ through a series-connected first BI, first BV, second BI, second BV, third BI, and connected to the second input of the third logical block I the second input of the first logical block And the output of the second BKON, whose input is connected to the output of the TNL, which is connected through BKNN to the second input of the second logical block And, the fourth logical block And connected to the output of the first BV, the second input of the third logical block And and the third input of the DFZ, the second output of which is connected to the second input of the control unit, and the third output to the third input of the first logic unit and, and the second output of the VUV is connected to the fourth input of the first logic unit I,

The drawing shows a schematic block diagram of a device for starting three-phase automatic reclosing of power lines,

The device is installed on power line 1, the second is connected via high-voltage switches 2 and 3 to power systems 4 and 5, respectively, through busbars B and 7, Line 1 is equipped at each of the ends of the TNL 8 and TT 9, and busbars 6 - with a TNSh voltage transformer 10, with the outputs of the TNL 8 and TNS 10 connected to the first and third inputs of the BCS 11, respectively, to the second input of which the first output of the TAPV 12 is switched. Between the TT 9 and the switch 2 there is a sequential circuit from BRT 13 RDC 14 / DFZ 15, BUV 16, TNL 8 is associated with the second turbine control unit BUV 16 through the VRRZ 14 The first output of the BRT 13 is connected to the first input of the CCU 10 via serially connected VZ 17 and BKON 18, the output of the BCS 11 is also connected to the first input of the CPU 16. The TAPV 12 is connected between the second output of the CCU 16 to the second inputs of the BKON 18 and the Third output of the SRB 14. included in the chain of series-connected BI 19-21 and BV 22 and 23, and BI 22 is connected between BI 19 and 20, and BV 23 - between BI 20

and 21. The second input VI g1 is connected to the second input of BI 19 and the output of BKON 24, the input of which is connected to the output of the TNL 8 directly and the second input of BI 20 through BKNN 25. Bi 26 is connected between the first input of BI 20 and the third input of DFZ 15, and to the second input of BI 26 is connected to the output of the BKON 24. KU 27 is connected between the output of BI 21 and the input of the BR 17, the second input is connected to the second input of KU 27

0 DFZ 15 output, the third output of which is connected to the third input of BI 19, the fourth input of which is connected to the second output of the CCU 16. The second input of the DFZ 15 is connected to the output of the TNL 8.

5 Short circuits on power lines 1 are designated 28–30, and areas of power lines within which these short-circuits arise, are designated respectively 31–33.

The device, similar to that described, is also installed at the other end of power lines 1 at switch 3, devices at both ends of power lines 1 include both the BKON 18 circuit and the BCS circuit 11. The time delay of the TAPV devices 12 at both ends of power lines 1 must

5 is somewhat different.

Consider the operation of the device for | case extension; the time delay TAPV 12 on the side of the switch 2 is 4 s, and on the other side of the transmission lines 1 - 2 s.

0

When k.z. 28 in zone 31, switch 2 turns off the short-circuit current, close to or 5-10% higher than its breaking capacity, similarly happens for switch 3 when short-circuit. thirty

5 in zone 33. Shutdown of the short-circuit current, which is close at slightly higher than the cut-off current normalized to the switch, yxysjuaeT conditions of its functioning. no3TON y especially

0 it is advisable to exclude the possibility that in a small time interval such a switch-off of a significant short-circuit current can be repeated. in case of unsuccessful TAPV LEP 1. This can be done by starting TAPV LEP 1 From the end, most

5 remote from the point of k.z. At the same time, even in the case of an illiquid c. the circuit breaker used to test the transmission lines 1 will shut off the short circuit current limited by the line reactivity. In the case of an unsuccessful one-time TAPV, the line is turned off and is no longer automatically turned on.

So, when k.z. in the zone 31 it is advisable to start TAPV transmission lines 1 from the switch 3 side, and in case of a short circuit. in zone 33, from the side of switch 2, since this prevents re-activation for possible non-removal of the short-circuit short circuit. switch, the first time has already disconnected a large current short circuit.

In the event of a short-circuit 28 in zone 31, according to information from TT 9, BRT 13 is triggered, and according to information from TT 9 and TNL 8, SRRZ 14 and DFZ 15 operate,

5, the last two blocks act on the opening of switch 2 through its CCU 16. The operation of BRT 13 at block 3 of this zone occurs as a result of the current short circuit flowing through switch 2 close to or exceeding the breaking capacity of switch 2, therefore From BRT 13 through BR 17 there is a signal to prohibit the command to turn on switch 2 through the VCON 18 circuit, and switch 2 can be automatically turned on only after testing power lines 1 with TAPV switch 3, the occurrence of voltage and running TAPV 12 for control of synchronism of linear voltage wives and walks and bus 6 with BCS 11. The control does not match the position of the switch 2 and its control key is implemented with the help of the CCU 16, and the signal from this block goes to the input of the TPV 12. A similar sequence of action takes place at the short circuit. 30 in zone 33, when the TAPV start of this end of the line is blocked along the BKON 18 circuit and TAG 3 of the switch 3 is allowed only along the chain of the BCS unit And of the same end of the line. When k, h. 29 in zone 32, there are no restrictions on the operation of switches 2 and 3, but the requirement of the TSP for a single TAPV of the LEP 1 is taken into account in the case of an unresponsive QFZ recloser pause, In accordance with the accepted TLP of the TAPV time on the LEP 1 after the line of its protection first from TAPV, voltage is applied to the line by switch 3, which TAPV controls the absence of voltage on the line and has a time delay of 2 s, i.e. smaller than the device TAPV 12 switch 2 (4c). If the TAPV transmission line 1 was successful, then the switch 2 is turned on from TAPV 12 through the BCS 11 circuit as usual. If the switching on of the VZ was unsuccessful on the asymmetrical short-circuit K3, then on the power transmission line 1 there is a short but one voltage or spirit phase, which is fixed by the BKNN 25 from the switch 2 side. This voltage transmits after switching off the power transmission line 1 by the switch 3. In the case of switch 2, however, TAPV will be prohibited along the BKON 18 circuit for the following reason. Already when short circuit 29 starts and switches off 2 and 3 from relay devices for power transmission lines 1, four signals arrive at input 19 BI: from SRRZ 14 , DFZ 15, from BUV 16 06 off switch and from the BC OH 24 about the absence of a line voltage on each of the three phases. After that, at the output of the BI 19, a signal is formed and enters the BS 22, where it is delayed by about 2 seconds (which corresponds approximately to the time required for the switch 3 to turn on from its TAPV). Then the signal from BV 22 is fed to the input of BI 20, to the second input of which, in the case of an unliquidated asymmetrical short-circuit, 29, the second signal also arrives at the transmission line 1 from BKNI 25. When they coincide, a signal appears at the output of BI 20, which, after passing through BV 23, and a delay of approximately 1 s here, arrives at BI 21 input, the second input of which also receives a signal from BKON 24 in the event of a TL 1 disconnection switch 3 after its unsuccessful TAPV and the disappearance of the voltage on the line. When the signals at the input of BI 24 coincide, its signal through KU 27 sends a signal that, after passing through BZ 17, the TAPV start-up switch 2 through VKON 18 passes through, and BAPV switch 2 is thus prohibited, TAPV switch 2 does not have a BPS 11 target due to the absence of linear voltage. If k.z. 29 was three-phase non-removable, then after switching on from TAPV switch 3 with a time delay of 2 s along the BKON circuit, the voltage on the transmission lines 1 at switch 2 does not vary. In this case, when a signal appears at the output of the BV 22, it will go to the input of BI 26, the second input of which will receive a signal from the BKON 24 output, and when these signals fall from the BI 26 output, a command will be sent to the DPS 15 input, where high-frequency transceiver of this protection. At this start, RF signals will go to the line, which, reflecting from a three-phase short circuit on the line, will return to the end of the transmission line 1, to switch 2 and go to the DPS protection receiver 15. Upon receiving the reflected signals from the output of the DPS unit 15, the signal goes through KU 27 to the input of the prohibition block BZ 17, and TAPV 12 switch 2 on the chain of the BKON 18 prohibit. The switched on state of the BKON circuits by the buttons of the power transmission lines 1 makes it possible to have a TAPV line in the event of a breakdown and a failure of the equipment of the NKBP TAPV at one of the ends of the line. Block KU 27 can be made on the basis of a traditional switch and allows, if necessary, to quickly bring the proposed device out of action. The blocks 19-21 and 26 and BV 22 and 23 are standard logical blocks AND and Time, manufactured on the basis of semiconductor elements. Blocks BKNN and BKON are also traditional and control respectively the presence of one or three of the phase elements. line voltage or the complete absence of voltage on any of the line phases.

In connection with the increase in the power of the energetic unions and the strengthening of the connections between their separate parts, the level of the maximum short-circuit currents. constantly growing. Such an increase can be gradual, and the level of the short-circuit current. comes to the limit of the diverting capacity of the switch

also gradually. Therefore, exceeding the maximum calculated TokoB k.z. under the breaking capacity of switches within 10-20%, it occurs quite often in networks of x 110 kV and above.

The proposed system of TAPV organization on a power transmission line with two-way power will allow the use of switches in the conditions mentioned above for short circuit currents.

Claims (1)

DEVICE FOR STARTING THE THREE-PHASE AUTOMATIC RETURNING ON the inconsistency of the position of the control switch key and off. of a power line switch, equipped at each end with a current transformer, voltage transformer, differential-phase protection, redundant relay protection unit, high-speed current relay, containing a linear circuit breaker control unit connected between the linear circuit breaker and the transformer • fock through a serial circuit of the voltage absence control unit , a prohibition unit and a high-speed current relay, the second output of which is connected to the second input of the control unit through the backup relay protection unit by a switch, to which the first output of the differential-phase protection is also connected, to the first input of which is connected the second output of the backup relay protection unit, and to the second - the line voltage transformer, the second input of the backup protection unit and the first input of the line voltage synchronism control unit and busbars adjacent to the power line and equipped with a bus transformer, voltage connected between the output of the voltage monitoring unit | the first output of the three-phase automatic restart block, to the input of which the second output of the circuit breaker control unit is connected, and to the second output is the second input of the voltage absence control unit, the line voltage transformer is connected to the third input, the third input of the voltage synchronization control unit is connected to the output bus voltage transformer, characterized in that, in order to increase the efficiency of the three-phase ° automatic re-inclusion due to the inclusion of the line in the work in all cases potentially successful three-phase automatic restart, it additionally contains four logical AND blocks, two time delay blocks, a second line voltage absence control unit (a line voltage control unit and a control key connected between the inputs of the prohibition unit and the third output of the backup relay protection unit through ^- the first logical block And, the first block of time delay, the second logical block And, the second block of time delay, the third logical block · And, and to the second a third of its logical block And is connected, the second one, the input of the first logical block And and the output of the second line voltage absence control unit, the input of which is connected to the output of the line voltage transformer, which is connected through the line voltage control unit to the second input of the second logical unit And, the fourth logical block And is connected to the output of the first block of time delay, the second input of the third logical block And and the third input of the differential-phase protection, the second output of which is connected to the second; 096S90I ^{, n} OS is the input of the control key, and the third output is to the third input of the first logical block And, and the second output of the control unit of the switch is connected to the fourth input of the first logical block I.