|
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese|
ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Section 3. Protection and automation Automation and telemechanics. Automatic reclosing (AR)
Encyclopedia of radio electronics and electrical engineering / Rules for the installation of electrical installations (PUE) 3.3.2. Automatic reclosing devices should be provided for quick restoration of power to consumers or intersystem and intrasystem communications by automatically closing switches disconnected by relay protection devices. Automatic restart should be provided: 1) overhead and mixed (cable-overhead) lines of all types with voltages above 1 kV. Refusal to use APV must be justified in each individual case. On cable lines of 35 kV and below, automatic reclosure is recommended in cases where it can be effective due to a significant probability of damage with the formation of an open arc (for example, the presence of several intermediate assemblies, power supply to several substations along one line), as well as in order to correct non-selective protection actions. The issue of the use of automatic reclosure on cable lines of 110 kV and above should be decided during the design in each individual case, taking into account specific conditions; 2) buses of power plants and substations (see 3.3.24 and 3.3.25); 3) transformers (see 3.3.26); 4) critical electric motors that are switched off to ensure self-starting of other electric motors (see 3.3.38). For the implementation of automatic reclosure according to clauses 1-3, automatic reclosing devices must also be provided on bypass, bus-coupling and sectional switches. In order to save equipment, it is allowed to perform a group auto-reclosing device on lines, primarily cable ones, and other connections of 6-10 kV. At the same time, the shortcomings of the group autoreclosing device should be taken into account, for example, the possibility of a failure if, after opening the switch of one of the connections, the switch of the other connection is turned off before the automatic reclosure device returns to its original position. 3.3.3. Automatic reclosing devices must be designed so that they do not operate when: 1) switching off the circuit breaker by personnel remotely or using telecontrol; 2) automatic disconnection from relay protection immediately after switching on by personnel remotely or using telecontrol; 3) disconnection of the circuit breaker by protection against internal damage of transformers and rotating machines, emergency automatic devices, as well as in other cases of disconnection of the circuit breaker when the action of automatic reclosure is unacceptable. AR after the action of the ACR (FACR) must be carried out in accordance with 3.3.81. AR devices must be designed in such a way that the possibility of repeated switching on to a short circuit is excluded in case of any malfunction in the device circuit. AR devices must be made with automatic reset. 3.3.4. When using automatic reclosure, as a rule, it should be provided for the acceleration of the relay protection in case of unsuccessful reclosure. Acceleration of the relay protection action after an unsuccessful AR is performed using an acceleration device after closing the circuit breaker, which, as a rule, should also be used when closing the circuit breaker for other reasons (from a control key, telecontrol or ATS device). When accelerating the protection after closing the circuit breaker, measures must be taken against the possible tripping of the circuit breaker by the protection under the action of a current surge during closing due to non-simultaneous closing of the phases of the circuit breaker. It is not necessary to accelerate the protection after switching on the circuit breaker, when the line is already energized by its other circuit breaker (i.e., in the presence of symmetrical voltage on the line). It is allowed not to accelerate the action of protection lines of 35 kV and below, made on alternating operational current, after automatic reclosure, if this requires a significant complication of protection and the time of their action in case of a metal short circuit near the installation site does not exceed 1,5 s. 3.3.5. Three-phase reclosing devices (TAPV) should be carried out mainly with start-up in case of a discrepancy between the previously given operational command and the disconnected position of the circuit breaker; it is also allowed to start the automatic reclosure device from protection. 3.3.6. As a rule, single- or double-acting TAPV devices can be used (the latter, if it is permissible under the conditions of the circuit breaker). A double-acting TAPV device is recommended for overhead lines, especially for single ones with one-sided power supply. In networks of 35 kV and below, double-acting TAPV devices are recommended to be used primarily for lines that do not have network redundancy. In networks with an isolated or compensated neutral, as a rule, blocking of the second AR cycle should be used in the event of a ground fault after the AR of the first cycle (for example, due to the presence of zero sequence voltages). The TAPV time delay in the second cycle should be at least 15-20 s. 3.3.7. To speed up the restoration of the normal mode of operation of the power transmission, the time delay of the TACR device (especially for the first cycle of double-acting reclosure on lines with one-sided power supply) should be taken as minimally possible, taking into account the time of the arc extinction and deionization of the medium at the fault site, as well as taking into account the time of the circuit breaker and its drive to restart. The time delay of the TAPV device on a line with two-way power supply must also be selected taking into account the possible non-simultaneous disconnection of the fault at both ends of the line; in this case, the operation time of protections intended for long-range redundancy should not be taken into account. It is allowed not to take into account the difference in time of disconnection of circuit breakers at the ends of the line when they are disconnected as a result of high-frequency protection operation. In order to increase the efficiency of a single-acting TAPV, it is allowed to increase its time delay (if possible, taking into account the work of the consumer). 3.3.8. On single lines of 110 kV and higher with single-sided power supply, for which, in the event of an unsuccessful RCST, the transition to long-term operation with two phases is acceptable, a double-acting ARRC should be provided at the supply end of the line. The transfer of the line to work in two phases can be carried out by personnel on site or by telecontrol. To transfer the line after an unsuccessful automatic reclosure to two-phase operation, phase-by-phase control of disconnectors or switches at the supply and receiving ends of the line should be provided. When transferring the line to long-term operation in two phases, if necessary, measures should be taken to reduce interference in the operation of communication lines due to the open-phase operation of the line. For this purpose, it is allowed to limit the power transmitted over the line in open-phase mode (if this is possible due to the operating conditions of the consumer). In some cases, if there is a special justification, a break in the operation of the communication line for the duration of the open-phase mode is also allowed. 3.3.9. On lines, the disconnection of which does not lead to a disruption of the electrical connection between the generating sources, for example, on parallel lines with one-sided power supply, TAPV devices should be installed without checking synchronism. 3.3.10. On single lines with two-sided power supply (in the absence of shunt connections), one of the following types of three-phase auto-recloser (or their combinations) must be provided: a) fast-acting TAPV (BAPV) b) non-synchronous TAPV (NAPV); c) TAPV with synchronization detection (TAPV US). In addition, a single-phase automatic reclosure (SAR) can be provided in combination with various types of TAPV, if the circuit breakers are equipped with phase-by-phase control and the stability of the parallel operation of parts of the power system in the SAR cycle is not disturbed. The choice of types of automatic reclosure is made on the basis of a combination of specific operating conditions of the system and equipment, taking into account instructions 3.3.11 - 3.3.15. 3.3.11. High-speed automatic reclosing, or BAPV (simultaneous switching on with a minimum time delay at both ends), is recommended to be provided on the lines according to 3.3.10 for automatic reclosing, as a rule, with a small difference in the angle between the EMF vectors of the connected systems. BAPV can be used in the presence of switches that allow BAPV, if, after switching on, the synchronous parallel operation of the systems is maintained and the maximum electromagnetic torque of synchronous generators and compensators is less (taking into account the necessary margin) of the electromagnetic torque that occurs during a three-phase short circuit at the machine outputs. The assessment of the maximum electromagnetic moment should be made for the maximum possible divergence of the angle during the BAPV time. Accordingly, the launch of the BAPS should be carried out only when the high-speed protection is triggered, the coverage area of which covers the entire line. The BAS should be blocked when the back-up protections are triggered and blocked or delayed when the breaker is operating. If, in order to maintain the stability of the power system in the event of an unsuccessful BAPS, a large amount of actions from emergency control automation is required, the use of BAPS is not recommended. 3.3.12. Non-synchronous auto-reclosing (NAR) can be used on lines according to 3.3.10 (mainly 110-220 kV) if: a) the maximum electromagnetic torque of synchronous generators and compensators that occurs during non-synchronous switching is less (taking into account the necessary margin) of the electromagnetic torque that occurs during a three-phase short circuit at the machine terminals, while the calculated initial values of the periodic components of the stator currents are taken as practical criteria for assessing the admissibility of the ARCR at an angle of inclusion of 180º; b) the maximum current through the transformer (autotransformer) at a switching angle of 180º is less than the short-circuit current at its terminals when powered by tires of infinite power; c) sufficiently fast resynchronization is ensured after AR; if a long asynchronous run is possible as a result of non-synchronous automatic reclosing, special measures must be taken to prevent or stop it. If these conditions are met, NAVC can also be used in the repair mode on parallel lines. When performing the NAVC, it is necessary to take measures to prevent excessive operation of the protection. For this purpose, it is recommended, in particular, to close the circuit breakers during ARCR in a certain sequence, for example, by performing AR from one side of the line with control of the presence of voltage on it after a successful ARCR from the opposite side. 3.3.13. Synchro-catching reclosure can be used on lines according to 3.3.10 to turn on the line with significant (up to approximately 4%) slips and an acceptable angle. The following AR execution is also possible. At the end of the line, which should be switched on first, an accelerated TAPV is performed (with fixation of the operation of high-speed protection, the coverage area of \uXNUMXb\uXNUMXbwhich covers the entire line) without line voltage control (UTAPV BK) or TAPV with line voltage absence control (TAPV ON), and on its other end is TAPV with synchronism catching. The latter is performed under the condition that the switching on of the first end was successful (this can be determined, for example, by monitoring the presence of voltage on the line). To capture synchronism, devices built on the principle of a synchronizer with a constant advance angle can be used. Automatic reclosing devices should be designed in such a way that it is possible to change the sequence of switching on switches at the ends of the line. When performing the AR US device, it is necessary to strive to ensure its operation with the largest possible frequency difference. The maximum allowable switching angle when using the automatic reclosure of the US must be taken taking into account the conditions specified in 3.3.12. When using the AR device US, it is recommended to use it to turn on the line by personnel (semi-automatic synchronization). 3.3.14. On lines equipped with voltage transformers, to control the absence of voltage (KOH) and control the presence of voltage (KNN) on the line for various types of TAPV, it is recommended to use bodies that respond to linear (phase) voltage and to negative and zero sequence voltages. In some cases, for example on lines without shunt reactors, it is possible not to use a zero-sequence voltage. 3.3.15. Single-phase automatic reclosing (SAR) can only be used in networks with a large earth fault current. SAR without automatic transfer of the line to a long-term open-phase mode in case of stable phase damage, the following should be used: a) on single heavily loaded intersystem or intrasystem power lines; b) on heavily loaded intersystem lines of 220 kV and higher with two or more bypass connections, provided that the disconnection of one of them can lead to a violation of the dynamic stability of the power system; c) on inter-system and intra-system lines of different voltage classes, if a three-phase shutdown of a high voltage line can lead to an unacceptable overload of low voltage lines with the possibility of violating the stability of the power system; d) on lines connecting large block power plants with the system without significant local load; e) on power lines, where the implementation of TAPV is associated with a significant load shedding due to a decrease in voltage. The OAPV device must be designed so that when it is taken out of operation or power is lost, the action of the line protections is automatically transferred to the disconnection of three phases in addition to the device. The choice of damaged phases in case of a short circuit to earth should be carried out using selective bodies, which can also be used as additional high-speed protection of the line in the SAR cycle, with TAPV, BAPV and one-way switching on of the line by operational personnel. The time delay of the ARCA should be tuned from the time of the extinction of the arc and the deionization of the medium at the site of a single-phase short circuit in the open-phase mode, taking into account the possibility of non-simultaneous operation of the protection at the ends of the line, as well as the cascade action of the electoral bodies. 3.3.16. On the lines according to 3.3.15, the APPV should be used in combination with various types of TAPV. It should be possible to prohibit TAPV in all cases of APPV or only in case of unsuccessful APPV. Depending on the specific conditions, TAPV may be performed after an unsuccessful APPV. In these cases, the operation of the TAPV is provided first at one end of the line with the control of the absence of voltage on the line and with an increased time delay. 3.3.17. On single lines with two-way power supply, connecting the system with a power plant of small capacity, automatic self-synchronization (APVS) of hydroelectric generators for hydroelectric power plants and TAPV in combination with dividing devices for hydro and thermal power plants can be used. 3.3.18. On lines with two-way power supply, in the presence of several bypass connections, the following should be used: 1) in the presence of two connections, as well as in the presence of three connections, if a simultaneous long-term shutdown of two of these connections is likely (for example, a double-circuit line):
For critical lines in the presence of two connections, as well as in the presence of three connections, two of which are a double-circuit line, if it is impossible to use ARCA for the reasons specified in 3.3.12, it is allowed to use the devices ARPA, BAPV or ARCS (see 3.3.11 , 3.3.13, 3.3.15). In this case, the AR and BAPV devices should be supplemented with an AR device with a synchronism check; 2) in the presence of four or more connections, as well as in the presence of three connections, if in the latter case a simultaneous long-term disconnection of two of these connections is unlikely (for example, if all lines are single-circuit), - automatic reclosure without checking synchronism. 3.3.19. Automatic reclosing devices with synchronism check should be performed at one end of the line with control of the absence of voltage on the line and with control of the presence of synchronism, at the other end - only with control of the presence of synchronism. Schemes of the automatic reclosure device with a line synchronism check should be the same at both ends, taking into account the possibility of changing the order of switching on the line switches during automatic reclosure. It is recommended to use an autoreclosing device with a synchronism check to check the synchronism of the connected systems when the line is turned on by personnel. 3.3.20. It is allowed to use several types of three-phase automatic reclosure on the line, for example, BAPV and TAPV with synchronism check. It is also allowed to use various types of automatic reclosing devices at different ends of the line, for example, UTAPV BK (see 3.3.13) at one end of the line and TAPV with voltage and synchronism control at the other. 3.3.21. A combination of TAPV with non-selective high-speed protections is allowed to correct the non-selective action of the latter. In networks consisting of a number of series-connected lines, when applying non-selective high-speed protections for them, it is recommended to use alternate auto-reclosing to correct their action; AR devices can also be used with protection acceleration up to AR or with a multiplicity of action (no more than three), increasing towards the power source. 3.3.22. When using a three-phase single automatic reclosure of lines supplying transformers, from the higher voltage side of which short-circuiters and separators are installed, in order to disconnect the separator during a dead pause, the time of operation of the automatic reclosure device must be detuned from the total time of switching on the short-circuiter and disconnecting the separator. When using a three-phase double-acting automatic reclosure (see 3.3.6), the time of action of the automatic reclosure in the first cycle according to the specified condition should not increase if the disconnection of the separator is provided for during the dead time of the second reclosure cycle. For lines where separators are installed instead of circuit breakers, the disconnection of separators in case of unsuccessful AR in the first cycle must be carried out during the dead time of the second AR cycle. 3.3.23. If, as a result of the action of automatic reclosure, non-synchronous switching on of synchronous compensators or synchronous electric motors is possible, and if such switching on is unacceptable for them, as well as to exclude replenishment from these machines of the damage site, it is necessary to provide for automatic shutdown of these synchronous machines in the event of a power failure or transfer them to asynchronous mode by turning off the AHS with subsequent automatic closing or resynchronization after voltage recovery as a result of a successful auto-reclosing. For substations with synchronous compensators or synchronous motors, measures must be taken to prevent unnecessary operation of the AFC during the operation of the automatic reclosure. 3.3.24. Auto-reclosing of busbars of power plants and substations in the presence of special protection of busbars and switches that allow auto-reclosing should be carried out according to one of two options: 1) automatic testing (setting tires under voltage by a switch from the automatic reclosure of one of the supply elements); 2) automatic circuit assembly; at the same time, one of the supply elements (for example, a line, a transformer) is switched on from the automatic reclosure device; if this element is successfully turned on, a subsequent, possibly more complete automatic restoration of the pre-emergency mode circuit is performed by turning on other elements. Reclosing busbars according to this option is recommended to be used primarily for substations without constant personnel on duty. When performing autoreclosing of tires, measures must be taken to exclude non-synchronous switching (if it is unacceptable). Sufficient sensitivity of busbar protection should be provided in the event of an unsuccessful reclosure. 3.3.25. At two-transformer step-down substations, with separate operation of transformers, as a rule, automatic reclosing devices for medium and low voltage buses should be provided in combination with AVR devices; in case of internal damages of transformers, ATS should operate, in case of other damages - automatic reclosing (see 3.3.42). It is allowed for a two-transformer substation, in the normal mode of which the parallel operation of transformers on buses of a given voltage is provided, to install, in addition to the automatic reclosure device, an ATS device designed for the mode when one of the transformers is put into reserve. 3.3.26. All single step-down transformers with a capacity of more than 1 MB A at substations of power systems that have a circuit breaker and maximum current protection on the supply side should be equipped with automatic reclosure devices when a transformer disconnection leads to a blackout of consumers' electrical installations. In some cases, the action of automatic reclosure is also allowed when the transformer is turned off by protection against internal damage. 3.3.27. If the automatic reclosure of the element switched on by the first circuit breaker connected by two or more circuit breakers is unsuccessful, the reclosure of the remaining circuit breakers of this element, as a rule, should be prohibited. 3.3.28. If there are switches with electromagnetic drive at the substation or power plant, if two or more switches can be simultaneously switched on from the automatic reclosure device, in order to ensure the required level of battery voltage when switching on and to reduce the cross-section of the cables of the power supply circuits of the closing electromagnets, as a rule, automatic reclosure should be performed as follows so that the simultaneous closing of several circuit breakers is excluded (for example, by using automatic reclosure on connections with different time delays). It is allowed in some cases (mainly at a voltage of 110 kV and a large number of connections equipped with automatic reclosure) simultaneous closing of two circuit breakers from automatic reclosure. 3.3.29. The action of automatic reclosure devices must be recorded by indicating relays, operation indicators built into the relay, operation counters or other devices of a similar purpose.
Air trap for insects
01.05.2024 The threat of space debris to the Earth's magnetic field
01.05.2024 Solidification of bulk substances
30.04.2024
▪ Found a mechanism that turns off the feeling of hunger ▪ Panasonic MeganeX Virtual Reality Glasses ▪ Neuroimplant - memory amplifier ▪ Thunderbolt from Intel will reach 20Gbps
▪ site section Low frequency amplifiers. Article selection ▪ article Correspondence of models and chassis of GRUNDIG TVs. Directory ▪ article Why can human tears have different chemical composition? Detailed answer ▪ Daikon article. Legends, cultivation, methods of application ▪ article Improved GIR. Encyclopedia of radio electronics and electrical engineering
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua |
See other articles Section 
Latest news of science and technology, new electronics:
All languages of this page