SU1721700A1 - Method of isolation of faulty section of power transmission line with two-side supply with aid of sectionalizing switches - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to relay protection and emergency control of power lines. The purpose of the invention is to improve the reliability of the allocation of the damaged area by reducing the number of switching switches. To do this, on part of the sectioning switches 5, located one at a time, starting from the automatic TSRI lirj of the reserve input (ABP) closest to the switch, control the voltage from one end only and re-adjust the time overcurrent protection (MTZ) of sectioning switches 5 and 8 upon the fact that the (at least short-term) voltage on these switches decreases below the set point for each sectioning switch, the value of which for a switch with voltage control from one (5) and two x (8) is selected the smallest of all conditions detuning from residual stress at the short-ends, respectively adjacent thereto and related (via a switch) circuit portions in total and included switch ABP. In this case, the value of the adjustable time delay of the overcurrent protection on switches 8 with voltage control at both ends is chosen to a level lower than the adjustable time delay on switches 5 with voltage control at one end and a shorter time delay of the ATS switch. Automatic reclosing (AR) of all disconnected sectional switches 5 is carried out simultaneously regardless of the presence or absence of voltage on them. 3 il. a (l c vj hO l - a

Description

The invention relates to power engineering, in particular, to methods of operation of emergency response systems for power transmission lines, mainly for agricultural purposes.

There is a known method for isolating a damaged section of a power line with two-sided power supply with the help of sectioning switches, which means that a protection kit is provided on the bypass switch that replaces the circuit breakers of the elements, which can replace, first of all, the protection with stepped characteristics of the lines connected to the buses, the last protection can be checked simultaneously with the switch. Therefore, ng an example, on the Bypass voltage switch Upa6. more than 110 kV typically provides distance protection and a cut-off current for multi-phase short-circuit and current protection against short-circuit to earth. If there is a main protection on the line with absolute selectivity (for example, a differential-phase current), the latter can switch to a bypass switch TT and act on the latter. In the case of busbar breakers, in the absence of bypass, the type of protection installed is usually chosen as for bypass switches,

With a bypass switch, this protection can be chosen more simply. In installations with a dual bus system with voltages greater than 35-110 kV, they usually operate simultaneously on both bus systems with the busbar switch on. In case of short circuits on the elements of the system and the failure of their protections or switches, in a number of cases, it is expedient to disconnect the bus connecting switch 1.

The closest to the present invention is a method for isolating a damaged section of a power line with two-sided power supply with the help of sectioning switches, which means that when a stable short-circuit appears on the line, the go / .eV switch is disconnected from the overcurrent time delay with a shorter time delay. MTZ sectioning switches, the same for all, while the latter are rebuilt upon the disappearance of the voltage in the (m AR pause for the minimum response time, the same for all and less time the main switch, turn on the main switch / .b from the automatic reclosing and disconnect the partitioning switches from the maximum protection, whether the short circuit current passed through, saTeiv, sequentially, starting from the closest to the main switch, switch on the section switches by the presence (occurrence) voltage on them for a given time, the same for all, the time gap, if, after turning on the sectioning switch, a short-circuit current appears, with the help of overcurrent protection this switch is turned off and locked / closed In the absence of a short-circuit current on the line in the control unit of this sectioning switch, they restore the initial value of the MTZ response time, with a delay time longer than the sum of the shutdown time of the main switch of the automatic reclosing switch and the disconnection and activation of the section switches located between the short circuit and the main switch, switch on the circuit breaker of the ATS point and then disconnect this circuit breaker and all sectioning switches from the circuit breaker between the ATS and the short-circuit point, then due to the presence of voltage the circuit breaker of the ATS point is switched on and in series. In fact, the presence of a power supply includes sectioning switches located between the ATS switches and the short circuit place, with the exception of the control unit of the mentioned switches, except for; closest to the short-circuit location, by the presence of voltage, the initial delay time of protection operation is restored for a specified time, the sectioning switch closest to the short-circuit location turns off the overcurrent protection with the minimum time delay and locks it in the off state, simultaneously with this switch then turn on the fact of the presence of a voltage of 2.

However, the described method is unreliable and requires a large number of switching switches.

The purpose of the invention is to increase reliability by reducing the number of switches by switches.

The supplied circuit is achieved by the method, which implies that when a stable short circuit appears on the line, the circuit breaker is disconnected, the overcurrent protection of which has the shortest time delay, control the voltage at both ends of the sectioning switches, rearrange the overcurrent time of the overcurrent sectioning switches located between short-circuit and the main switch, for a value less than the shutter speed, the time of the overcurrent protection MTZ, then successively, our head-switch, performs the automatic reclosure circuit breakers on the fact of the presence (on access) of a voltage on them for a predetermined time, while, if the circuit breaker is turned on for a predetermined period of time, a short-circuit current appears, then with the help of an overcurrent switch this switch is turned off and blocked position, in the absence of short-circuit current on the line after turning on the sectioning switch with a time delay that is the same for all and less AR, restore the initial time delay of the overcurrent overcurrent switch of this switch, with a given time delay exceeding the maximum possible time m automatic reduction of voltage on the damaged site include ABP switch, which has an overcurrent constant time delay, time delay rearrange MTZ sec- tsioniruyuschihvyklyuchateley,

located between the short-circuit point and the ATS switch, when the short-circuit current flows in the line, the circuit breakers are disconnected, whose MTZs have the shortest time delay, and then sequentially, starting with the ATS circuit breaker, the ARC is disconnected due to the presence (occurrence) of voltage within a specified time, while on all the mentioned sectioning switches, except the one closest to the short-circuit location, after maintaining the voltage for a specified time, the initial time delay of the overcurrent relay is restored, and the closest to the short-circuit location is off The user is disconnected using the overcurrent protection device and blocked in the disconnected position, on part of the sectioning switches located through one, starting from the one closest to the circuit breaker, the voltage is monitored only from one end, and the above-mentioned redesign of the overcurrent time of the overcurrent protection at least a short-term voltage lower than the setpoint set for each sectioning switch, the value of which for the switch with the control of the presence of voltage from one and two ends is chosen as the lowest out of condition oiki from residual voltage on the on switch with short circuit at the ends of the adjacent and adjacent (through one switch) sections in the complete circuit and the ATS switch on, with this value of the redesigned time of the overcurrent overcurrent on sectioning switches with control from both ends, they are selected to the level of a longer tunable time delay of the overcurrent protection at the switches, at which they control voltages at one end and at a shorter time delay of the overcurrent protection of the overcurrent protection switch, ARV of all disconnected se Voltage control switches with voltage control from one end, carry out simultaneously regardless of the presence or absence of voltage on them, in the dead time of the automatic reclosing cycle, sectioning switches with voltage control at both ends are disconnected due to the absence of current and voltage and storing the prior short circuit current .

Figure 1 shows the diagram of the power line; Fig. 2 is a control circuit of a sectioning switch; FIG. 3 shows a control unit for a sectioning switch.

The power line includes the main switches 1 and 2, each of which is equipped with a relay protection unit 3 and an AR device 4. On the line there are sectioning switches 5 with voltage control at one end using voltage sensors 6 (voltage transformers), control unit 7 for sectioning switches, section switches 8 with voltage control at both ends using sensors 6 and 9 tension Voltage relays 10 and an AVR switch 11 are connected to voltage sensors 6.

FIG. 2 shows a control circuit of a sectioning switch 5 with monitoring the presence of voltage from one end, a contact 12 of a voltage relay 10, a time relay 13 closing with a time delay a contact 14 of a relay 13 times an acceleration relay 15 or an MTZ time delay adjustment relay , contact 16 of relay 15, auxiliary contact 17 of a switch, a charge resistance 18, diodes 19, capacitors 20, an AR input pad 21, a pointing relay 22, and the emergency block contacts 23 of the switch are closed when the switch is turned on and during emergency shutdown of the switch,switch-off solenoid 24, spring or cargo actuator ready contact 25 for switching on, switch 26 contact block, spring or cargo actuator ready contact 27 for switching on, switch 28 contact block, automatic reclosing relay 29, resistance 30, contact 31 relays 29 automatic reclosing time, automatic circuit breaker 32 operating current of control circuits, contact 33 of voltage relay 10, contact 34 of relay 15.

FIG. 3 shows the control unit of the sectioning switch 8, voltage sensors 6 and 9, voltage relay 10 connected to one interfacial voltage, for example, AV d-etchik voltage 6, contact 12 relay 10 per -1 rp, relay 13 time, contact 14 time relay 13, closing with time delay, intermediate acceleration relay 15 or resetting the time relay MTZ to a shorter time, contact 16 relay 15, block-contact 17 switch, automatic current control device 32, voltage contact 33 of relay , contact 34 relay 15, voltage relay 35 is connected to voltage sensor 9 and, preferably, to another interfacial voltage, as compared with voltage relay 10, for example, AC, voltage relay 36 is connected to a third interphase voltage, for example CA, contact 37 voltage relay 35, contact 38 voltage relay 36, contact 39 voltage relay 35, contact 40 voltage relay 36, current relay 41 and 42, which react to possible short-circuit currents, current relay 43, which reacts to the absence of current through a switch, current contact 41, current contact 45, current resistance42, 46 diodes 47, capacitors 48, charge resistance 49, diodes 50, capacitors 51, clock cycles 52 relays 43 TOKJ, contacts 53 relays 10 voltages, contacts 54 relays 35 voltages, intermediate relay 55 for short-circuit current memory, contacts 56 for relay 55, pointer 57 relays, auxiliary contacts 58 for the switch, electromagnet 59 for the opening of the switch, contacts 60 voltage relay 10, contacts 61 voltage relay 35.

The method is carried out as follows.

To illustrate the operation of the network indicated in Fig. 1, the time delay of the overcurrent protection of the main switches 1 and 2 is taken to be 2 s. The constant time delay of the MTZ switch 1.1 AVR is assumed to be 1.5 s. The time delay M GB of sectioning switches 5 and 8 before switching to the shortest one will be equal to 2.5 s. The rebuilt (for a shorter) time delay of the overcurrent protection sectioning section switches 5 with voltage control from one end is taken equal to 0.5 s.

For sectioning switches 8 with the control of the presence of a straight line at both ends, we take a rebuilt (for a smaller) shutter speed of the MTZ period of 1 s.

Consider a short circuit in the n, e section between the third, counting from the head switch 1, the sectioning switch 5 and the fourth / counting from the head switch 1, the sectioning switch 8 (hereafter, the section switches start from the half-closed switch 1).

Select the voltage setpoint by which the time delay of the overcurrent protection is switched to a smaller value.

For the third sectioning switch 5 with the control of the presence of voltage from one end, the setpoint voltage is selected from the condition of detuning from the smallest of residual stresses at short-circuit at the end of adjacent areas, i.e. with short circuit

0, respectively, at the terminals of the second and fourth sectioning switches 8 and the short circuit current flowing through the specified third sectioning switch 5 or from the switch 11 of the ATS, if

5 at the terminals of the second sectioning switch 8, or from the main switch 1, if there is a short circuit at the terminals of the fourth sectioning switch 8.

Let this residual voltage on the third sectional switch 5 be equal to 10 V secondary at fault at the terminals of the second sectioning switch 8 and 20 V secondary at fault at the terminals of the fourth

5 sectioning switch 8.

The voltage setting is taken equal to 8 V. This setting is set on the relay 10 and the voltage (figure 1) connected to the voltage sensor 6 (transformer

0 voltage).

For the second partitioning switch 8, the voltage setting is selected by the detuning from the lowest residual voltage npt. KZ E end of adjacent (through

5 one switch) and let the value of this residual voltage be 30 V secondary as with short circuits at the terminals of the fourth sectioning switch 8 and short circuit current flowing from the head switch of body 1 through the second sectioning switch 8, and with short circuit at the terminals of the head switch 1 and short circuit current flowing through the second sectioning switch 8 from the switch 11 AVR.

5 Voltage setpoint is assumed to be 24 V secondary for the second partitioning switch 8.

If a stable short circuit occurs in the area between the third and fourth sectioning switches 5 and 8, it is possible to disconnect the first sectioning switch 5 or the second sectioning switch 8 or the head switch 1 closest to the short circuit location.

5 The closest to the fault location sectionalization switch 5 is first shut off if the fault is three-phase, or between those phases whose residual voltage controls the voltage relay 10 (figure 1) and the residual voltage on it is lower

setpoint voltage, which switch the time delay MTZ to a smaller value. In this case, when a short-circuit relay 10 occurs (Fig. 1), it opens its contacts 12 in the intermediate relay circuit 15 and closes its contacts 33, which connect a shorter time delay of the overcurrent protection. When contact 12 is closed, intermediate relay 15 will disconnect and close its contacts 34 which parallel to the contacts 33 also connect a shorter time delay of the overcurrent protection, for example 0.5 s. Contacts 33 and 34 are connected in parallel to increase the reliability of the connection of a shorter shutter speed MTZ. The third partitioning switch 5 is disconnected from the overcurrent protection relay with the overload time of the overload protection system rebuilt for a shorter time. Regardless of the presence or absence of voltage, the automatic reclosing time relay 29 is started up by its shunting by means of the drive readiness 27 to be switched on sequentially and the auxiliary contacts 28 of the switch. The sectioning switch is switched on along the circuit: the point between the diodes 19 and the capacitor 20, the contacts 31 of the time relay 29, the pad of the AR input 21, the indicating relay 22, the emergency block contacts of the switch 23, the solenoid 24 on, the block 25 on the drive ready to turn on, the block -contact switch 26, the second capacitor plate 20. The sectioning switch 5, closest to the fault location, turns on from the AR, is disconnected again from the overcurrent protection with a rearrangement by a shorter time overcurrent protection, for example, 0.5 s, entered by contacts 33 and 34 respectively of the voltage relay and intermediate relay 15. The switch is locked in the off state.

The first shutdown of the second sectioning switch 8 with a short circuit in the area between the third and fourth sectioning switches 5 and 8 occurs if the residual voltage of at least one of the three voltage relays 10, 35 and 36 (Fig. 3) of the second sectioning switch 8 is less in front of the setpoint voltage, which is used to switch the time delay of overcurrent protection to a smaller, but at the same time, residual voltage on the relay 10, the voltage of the third sectioning switch 5 is greater than the setpoint voltage, m nshe which the switching dwell time at a lower overcurrent or short circuit between the phases, which does not include the relay 10 voltage of the third switch 5 is partitioned.

In order to disconnect the second partitioning switch 8, it is first necessary that the third partitioning exhauster 5 does not switch to

a shorter time delay of the overcurrent protection at the onset of a short circuit, and at the second sectioning switch 8, at least one of the three relays 10.35 and 36 voltage (Fig. 3) the residual voltage was less in front

0 set point voltage. At least one of the three contacts 12, 37, and 38, respectively, the voltage relays 10, 35, and 36 (Fig. 3) will open the overcurrent relay relay circuit 15 for a shorter time and close

5, a shorter time overcurrent connection circuit with at least one of the contacts 33.39 and 40, respectively, of the relay 10.35 and 36 voltage, and also contacts 34 of the intermediate relay in parallel with these contacts

0 relay 15. The second sectioning switch 8 is turned off with an adjustment for a shorter time delay of the overcurrent protection, for example, 1 s. After the second sectioning switch 8 is disconnected, the voltage from the third sectioning switch 5 closest to the short circuit will be removed and, as described earlier, a shorter time delay of the overcurrent protection of this switch is connected.

After the second sectioning switch 8 is turned off, its automatic reclosing is started up by the presence of voltage on the voltage relay 10 (Fig. 3) by closing its contacts 60.

The second partitioning switch 8 is turned on by the presence of voltage (as

5 sectional switch with voltage control at both ends) and the third sectional switch 5 closest to the fault location is turned off with a resetting switch for a shorter time delay

0 MTZ, for example 0.5 s, the value of which is less than the adjustment for a shorter time delay MTZ of the second sectioning switch is equal to, for example, 1 s (as a sectioning switch with control

5 voltages at both ends). Then, as described above, the partition switch 5, closest to the short-circuit location, is switched off again from the automatic reclosing, is again disconnected from the overcurrent protection with the overload protection system rebuilt to a shorter time delay and blocked in the off state.

When a short circuit occurs in the area between the third and fourth section switches 5 and 8, the first

5 head switch 1, if the residual voltages at the second and third sectioning switches 8 and 5 are higher than the predetermined voltage settings, according to which the overcurrent time of the overcurrent protection switches to a smaller one, for example, at short circuit

the leads of the fourth sectioning switch 8 between the third and fourth sectioning switches 5 and 8 with the time delay of the overcurrent protection of the main switch 1, for example 2 seconds, the slower overloading time of the overcurrent protection sectioning switches for 2.5 seconds, the main switch 1 is turned off. The sectioning switches 8 with the control of the presence of voltage at both ends are turned off due to the absence of current and voltage and the storage of the preceding short-circuit current.

When a short circuit occurs, any of the current relays 42 and 43 will close and close its contacts 44 and 45 in the response circuit of the intermediate relay 55 (FIG. 3).

Intermediate relay 55 operates in a circuit: a point between the diodes 47 and the capacitor 48, one of the closed contacts 44 or 45, or both together (in parallel with the contacts 44 and 45), the relay 55, the second capacitor plate 48.

The circuit breaker trips on the circuit: the point between the diodes 50 and the capacitor 51, normally closed contacts 52 current relays 43, normally closed contacts 53 voltage relays 10, contacts 54 voltage relays 35, contacts 56 of intermediate relay 55 with a delay time delay , pointer relay 57, auxiliary contacts 58 of a switch, a shutoff electromagnet59, a second capacitor plate 51. The second partitioning switch 8 with the control of the presence of voltage on both sides is turned off. Immediately after turning off the head switch 1, on the sectioning switches located between the short-circuit and the head switch 1, the time delay of the overcurrent protection device is changed to a smaller one, which is less than 0.5 s for sectioning switches 5, for example, rebuilt for a shorter time MTZ second partitioning switch 8 with the control of the presence of voltage from both ends, for example 1 sec.

A shorter time delay of the overcurrent protection overcurrent of sectionalizing switches 5 is connected with the closure of the contacts 33 and 34, respectively, of the voltage relay 10 and the intermediate relay 15, as described earlier. A shorter time delay MTZ of the second sectioning switch 8 with the control of the presence of voltage at both ends is introduced by closing the parallel-connected contacts 33,34,39 and 40, respectively, of the voltage relay 10, the intermediate relay 15, the voltage relay 35 and 36.

After switching on the ARC of the head switch 1 on the switch 5 next to it, the voltage relay 10 activates and closes its contacts 12. Time relay 13 is connected to the operating current voltage through contacts 12 and the auxiliary contacts 17 of time switch 13, after a specified time, for example, 3 seconds, we return the time delay of the overcurrent protection to the initial state. After a time, for example 3.5 seconds, longer delay time of resetting the overcurrent protection, the second sectioning switch 8 is turned on from the automatic reclosing and the third sectioning switch 5 closest to the short-circuit location is turned off with the overload time adjusted for a shorter time delay and, as described, turns on again from auto reclosing and again disconnected and locked in the disconnected state.

By the time the third sectioning switch 5 closest to the short-circuit location of the second sectioning switch 8 is turned on, the initial time delay of the overcurrent protection by opening the contacts 33.39 and 40 immediately after the occurrence of a voltage on the voltage relay 10.35 and 36 (Fig. 3) is restored and after the time relay 13, connected to the operating current voltage by contacts 12.37 and 38 and the auxiliary contacts 17 of the switch, counts the set time and closes its contacts 14; the intermediate relay 15 will work and will open its contacts 34 in the connection circuit of a shorter time delay of overcurrent protection. The time delay of the overcurrent protection overcurrent of the second partitioning switch 8 is reset.

After a time longer than the possible time of automatic recovery of the voltage in the damaged area, switch on the AVR switch 11, located between the fault point and the ATS switch, the sectional switch 5 that is closest to the ATS switch, turns off with a shorter time delay MTZ, the fourth section switch 8s monitoring the presence of voltage at both ends, which is closest to the fault location, is turned off by the absence of current and voltage and the memorization of the preceding fault current.

The sectioning switch 5 closest to the ATS switch is turned off regardless of the presence or absence of reclosing voltage, the fourth sectioning switch 8 is turned on after the ACB switch voltage has been applied to the voltage relay 35, which by its contacts 61 initiates the reclosure by the time switching on from the automatic reclosing of the fourth sectioning switch 8, on the sectioning switch 5 closest to the AVR switch, the initial time delay of the overcurrent protection relay, the sectioning switch 8 closest to the fault location, is restored after for prison from APV again disconnected from overcurrent rebuilt to a smaller time delay and blocked in disconnected state.

The damaged area is highlighted.

Claims (1)

Claim Method A method for isolating a damaged portion of a power line with two-way power using section switches means that when a stable short circuit (short circuit) occurs on a line, the circuit breaker is disconnected, the overcurrent protection (MTZ) of which has the shortest time delay both ends of the sectioning switches, rebuild the time delay of the overcurrent protection of sectioning switches located between the short circuit and the main switch, on the less than the time delay of the overcurrent protection of the main switch, then successively, starting with the main switch, automatic re-activation (AR) of the disconnected switches is performed upon the presence (appearance) of the voltage on them for a predetermined time; a short-circuit current appears in the circuit breaker for a given period of time, then with the help of overcurrent protection this switch is disconnected and blocked in the open position, if there is no short-circuit current on the line after the sectionalizing switch is turned off Belts that are the same for all and shorter AR time, restore the initial time delay of the overcurrent protection of this switch, with a given time delay exceeding the maximum possible time of automatic voltage recovery in the damaged section, turn on the automatic reserve transfer switch (MTD) of which has a constant shutter speed time, rebuild the time delay of the overcurrent protection of sectionalizing switches located between the short circuit and the automatic transfer switch, and the flow of short-circuit current in the line, the circuit breakers are disconnected, the overcurrent overload relays of which have the shortest time lag switches on the fact of the presence (occurrence) of the voltage on them for a predetermined time, while on all sectioning switches, except the one closest to the short-circuit location, after the voltage is maintained for a specified time, the initial time delay of the overcurrent relay is restored, and the closest to the place A short circuit breaker is disconnected by means of an overcurrent protection device and blocked in an open position, characterized in that In order to increase the reliability of the allocation of a damaged area by reducing the number of switching by switches, parts of sectioning switches located through one, starting from the closest to the circuit breaker, control the voltage only from one end, while redesigning the overcurrent time of the overcurrent at least briefly lower than the setpoint set for each sectioning switch, the value of which for a switch with voltage control from one and two ends is chosen as the smallest of the conditions for tuning from residual voltage on the on switch with short-circuit at the ends of the adjacent and adjacent (through one switch) sections in the full circuit and the ATS switch, while the value of the adjustable time delay of the overcurrent protection on sectionalizing switches with voltage control at both ends is chosen to be lower than the adjustable time delay of the overcurrent protection on the switches on which the voltage is controlled from one end, and lower than the time delay of the overcurrent protection of the circuit breaker AVR, automatic reset all disabled Partitioning switches with voltage control from one end carry out simultaneously regardless of the presence or absence of voltage on them; in the dead time of the automatic reclosing cycle, sectioning switches with voltage control both ends are disconnected due to the absence of current and voltage and the memorization of the preceding short-circuit current. with r-t-tn LVlj silt AND A and Ш 28 mouth J Pl. vzm am 0 // r2 L§-3-5J