CN110233478B - Method and system for quickly reconstructing millisecond-level power supply network after power grid fault - Google Patents

Method and system for quickly reconstructing millisecond-level power supply network after power grid fault Download PDF

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Publication number
CN110233478B
CN110233478B CN201910490040.1A CN201910490040A CN110233478B CN 110233478 B CN110233478 B CN 110233478B CN 201910490040 A CN201910490040 A CN 201910490040A CN 110233478 B CN110233478 B CN 110233478B
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circuit breaker
fault
substation
reconstruction
power supply
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CN110233478A (en
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段刚
娄霄楠
张琦
张玉含
刘念
郑亮亮
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Beijing Sifang Project Co ltd
Beijing Sifang Automation Co Ltd
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Beijing Sifang Project Co ltd
Beijing Sifang Automation Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
    • H02J13/00019—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using optical means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/001—Methods to deal with contingencies, e.g. abnormalities, faults or failures
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/388—Islanding, i.e. disconnection of local power supply from the network
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/16—Electric power substations
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • Y04S10/52—Outage or fault management, e.g. fault detection or location

Abstract

The invention provides a method and a system for quickly reconstructing millisecond-level power supply network after power grid failure. The method comprises the steps that a rapid network reconstruction main station collects power grid state information from a substation or a substation of a power plant and compares the power grid state information with a built-in control strategy table which is likely to have faults; when the occurrence of an expected power grid splitting fault is monitored, a closing pre-starting signal is sent to the substation corresponding to the plurality of recovery networking circuit breakers; after the fault is cleared, the substation identifies the clearing time according to the local information and sends a synchronous closing detection signal to the corresponding local recovery networking circuit breaker; meanwhile, the main station independently monitors the clearing of the fault, sends a back-up detection synchronization closing signal to the corresponding recovery networking circuit breaker, and realizes the re-grid connection of the disconnected power grid within 150ms after the disconnection based on the mechanism. And after the power grid is interconnected, the breaker forming the electromagnetic ring network is disconnected.

Description

Method and system for quickly reconstructing millisecond-level power supply network after power grid fault
Technical Field
The invention relates to the technical field of power grid control, in particular to a method and a system for quickly reconstructing millisecond level of a power supply network after a power grid fault.
Background
After an external network accident or an internal network fault occurs in the regional power grid, an island of the full-region power grid or the partial-region power grid may be formed due to the interruption of a partial power supply path. When the lost power source has a large ratio and the power generation and the load in the island have a large power difference, the frequency stability of the island power grid can be realized only by taking measures of power cutting or load shedding, which not only has a large influence on the production and power supply, but also has high difficulty in maintaining continuous and stable operation of the temporarily stable island power grid in the follow-up process. Therefore, after the power grid is isolated from the island due to the fault, a new power supply path is quickly reconstructed, the connectivity and integrity of the power grid are recovered, the power grid as large as possible is formed, and the method is the most direct measure for ensuring continuous power supply and stable power supply.
After the power failure of the load such as the motor, if the voltage is lower than 0.8 times of the rated voltage and the duration time exceeds 150ms, the load can be tripped by the undervoltage protection. Therefore, the fast restoration of power after islanding should be completed within 100 ms. The existing power supply fast switching device is usually switched out within 10ms after the switch is switched off, and the power supply switching is completed within 100 ms. However, the conventional power supply fast switching device has the following disadvantages:
(1) the existing fast switching device can only acquire information of local buses or incoming lines, cannot consider the recovery of a power supply path from the perspective of the whole network, and particularly cannot perform multipoint switching-on according to remote fault information, so that an optional channel for recovering the power supply path is limited, and the probability of recovering the connectivity and integrity of a power grid is reduced.
(2) The conventional fast switching needs to be started by depending on switch tripping or related protection signals, however, when a remote system external fault occurs in a power grid, an area monitored by the conventional power supply fast switching device has no switching action, the fast switching device cannot be started, but the frequency and the voltage are broken down, and if the frequency and the voltage are not timely isolated from the fault system and switched to a normal power supply system, a load supplied by the fault power supply loses a power supply.
(3) The on-site selection of power sources may have insufficient capacity, which may require more power source capacity to be selected for support at a remote location.
(4) A single power supply path may have overload problems where multiple power supply paths are required.
(5) The power supply fast switching has the possibility of failure due to the fact that the synchronous condition does not meet the requirement, and after the conventional single fast switching point fails, the whole fast switching defense line fails without backup measures.
In addition, the existing method called as a power grid network reconstruction method or a power grid self-healing method is based on the conventional switching operation, and power supply is recovered after load is cut off and is shut down due to power grid faults; therefore, this kind of solution cannot satisfy the requirement of recovering the power supply within 150ms after the fault is removed, and cannot achieve the purpose of recovering the power supply without stopping the motor and other loads, and thus is out of the same range as the problem solved by the present invention.
Disclosure of Invention
In view of the above, the invention provides a method and a system for quickly reconstructing millisecond-level power supply network after power grid failure.
According to an aspect of the invention, a method for the millisecond-level fast reconstruction of a power supply network after a grid fault is provided, which comprises the following characteristic steps:
step 1: the fast reconstruction master station collects all state information of the monitored power grid from the fast reconstruction substation positioned in the transformer substation or the power plant, compares the state information with built-in fault set characteristics which possibly occur, and judges whether the monitored power grid has a breaker or a fault which causes the breaker to be disconnected, namely, carries out real-time perception of the power grid disconnection fault;
step 2: when the rapid reconstruction master station monitors that a preset fault which possibly causes the circuit breaker to be disconnected occurs, sending a closing pre-starting signal to a rapid reconstruction substation where a plurality of recovery networking circuit breakers corresponding to a first type of circuit breaker are located, wherein the first type of circuit breaker can be the circuit breaker which can be disconnected;
and step 3: if the fast reconstruction master station monitors that the outer network has a disconnection fault and is broken down, disconnecting a second type of circuit breaker, and simultaneously sending a synchronous detection closing signal to a fast reconstruction substation where a plurality of recovery networking circuit breakers corresponding to the second type of circuit breaker are located, wherein the second type of circuit breaker is an outer network interconnection circuit breaker;
and 4, step 4: the fast reconstruction substation receiving the closing pre-starting signal identifies the fault clearing time in real time according to the local measurement information, and immediately or with specified time delay sends a synchronous closing detection signal to the recovery networking circuit breaker corresponding to the first type of circuit breaker when finding that the fault is cleared or is being cleared;
and 5: the method comprises the steps that a rapid reconstruction master station monitors the on-off signals of first-class circuit breakers in a whole network range in real time, and when one first-class circuit breaker is found to be on or being on, a backup detection synchronous closing signal is sent to a plurality of recovery networking circuit breakers corresponding to the first-class circuit breakers immediately or in a specified time delay mode;
step 6: checking synchronization and locking execution of synchronous closing: checking whether two sides of the switched-on recovery networking circuit breaker meet synchronous switching-on conditions or not and whether in-zone fault locking does not exist or not and standby power supply fault locking does not exist, and if the two sides of the switched-on recovery networking circuit breaker meet the requirements, sending a switching-on execution signal to the recovery networking circuit breaker;
and 7: after the power grid is interconnected, disconnecting the overcurrent recovery networking circuit breaker or limiting the current;
and 8: unfastening the existing high-low voltage electromagnetic looped network;
and step 9: resetting of the power supply network rapid reconfiguration system: and (5) resetting each device of the power supply network rapid reconstruction system 200ms after the step 8 is finished, and returning to the step 1 to monitor the next power grid splitting event.
According to another aspect of the invention, a millisecond-level fast reconstruction system of a power supply network after power grid failure is provided based on the method, the system comprises a fast reconstruction main station and a fast reconstruction substation, wherein the main station and the substation are realized based on a hardware device and a platform for safe and stable control of a power system meeting the requirements of national standard and row standard, and the hardware performance of the main station and the substation meets the following conditions: the sampling rate of the power frequency recording data of the substation is not less than 1200Hz, the calculation processing period of the measured data of the substation is not more than 0.83ms, the information transmission period and the instruction scanning period of the main station and the substation are not more than 1.67ms, a 2M data private network is adopted for communication among devices in the system, and the main station and the substation respectively adopt hard wiring to collect voltage and current equivalent measured data from a protection CT and a PT.
The technical effects are as follows:
(1) and a strategy master station for centralizing key information of the whole network is set, the equipment information of each power supply area of the whole network is obtained through the master station, the potential fault is determined according to the equipment information and the network topology, and a plurality of circuit breakers corresponding to the potential fault are controlled. According to the power supply network rapid reconstruction method provided by the embodiment of the invention, the 10 ms-level rapid recovery of a power supply path is realized from the perspective of the whole network: the multiple circuit breakers corresponding to the potential faults are determined, when the potential faults occur, the multiple circuit breakers can be controlled, rapid switching-on at multiple grid-connected points is achieved, the success rate of recovering the disconnected power grid to the network is improved, and therefore continuous operation without stopping of loads such as motors and station service power is achieved. The multipoint switching-on is also beneficial to improving the success rate of the recovery interconnection of the power grid by utilizing the characteristic that the switching-on synchronous conditions of all circuit breakers are different due to different bus voltage change processes; the multi-point switch-on also reduces the possibility of overcurrent of a switching path of a newly-connected power supply.
(2) When a potential fault which can cause the disconnection of the circuit breaker is actually monitored, the main station sends a pre-starting signal to the related recovery networking circuit breaker substation, the pre-started substation judges the clearing time of the remote fault according to the local measurement information, namely the disconnection time of the first or second circuit breaker, and then actively starts the synchronous closing of the recovery networking circuit breaker on the spot, so that the situation that the closing of the recovery networking circuit breaker needs to be started by means of remote communication after the power grid is disconnected is avoided, and the remote communication time is saved.
(3) And the master station sends a quick closing signal to the substation corresponding to the plurality of broken circuits when detecting that the voltage of the bus with the lowest voltage is recovered to be normal. Therefore, if the substation does not successfully judge that the voltage of the bus with the lowest voltage is recovered to be normal, the substation can carry out remediation through the quick closing signal sent by the main station.
(4) A tripping outlet signal of a protection or automatic device is used as a trigger signal for rapid switching-on, and a fault power grid circuit breaker is ensured to break a fault first and then switch on a standby power supply circuit breaker through certain time delay, so that switching-on failure caused by incomplete disconnection of the circuit breaker of a fault power grid is avoided.
(5) When a remote system external fault (external network breakdown) occurs in a power grid, the area monitored by the conventional power supply quick switching device has no switching action, and the quick switching device cannot be started; however, the frequency and the voltage are collapsing, and the method can actively isolate the frequency and the voltage from a fault system in time and switch to a normal power supply system, so that the stability and the normal operation of a power grid are ensured.
(6) According to the method of the embodiment of the invention, when the electromagnetic ring network is successfully formed by switching on the plurality of circuit breakers, the electromagnetic ring network can be disconnected in time, so that the power grid can stably operate.
Other features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention.
Fig. 1 shows a block diagram of a physical structure of a power supply network rapid reconfiguration system according to an embodiment of the present invention.
Fig. 2 shows a flow chart of a method for fast reconstruction of a power supply network after a grid fault according to an embodiment of the invention.
Fig. 3 shows a schematic diagram of the rapid reconfiguration of the power supply network in the event of an internal fault in the regional power grid.
Fig. 4 shows a schematic diagram of the rapid reconfiguration of the supply network in the event of a disconnection fault remote from the external network.
Detailed Description
Various exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In some instances, methods, procedures, components, and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present invention.
In order to solve the technical problem of a conventional power supply quick switching device, the invention provides a power supply network quick reconstruction method after a power grid fault.
Fig. 1 shows a block diagram of a physical structure of a power supply network rapid reconfiguration system according to an embodiment of the present invention. As shown in fig. 1, a power supply network fast reconfiguration system (hereinafter referred to as a system) according to an embodiment of the present invention may include a fast reconfiguration master station (hereinafter referred to as a master station) and a fast reconfiguration slave station (hereinafter referred to as a slave station), where the master station and the slave station may be implemented based on a software and hardware platform of a power system safety and stability control device meeting national and international requirements, and hardware performance of the master station and the slave station satisfies the following conditions: the substation power frequency recording data sampling rate is not less than 1200Hz, the substation measurement data calculation processing period is not more than 0.83ms, the main station and substation information transmission period and the instruction scanning period are not more than 1.67ms, a 2M data private network is adopted for communication among devices in the system, the main station and the substation respectively adopt hard wiring to collect voltage and current equivalent measurement data from a protection CT (current transformer) and a PT (potential transformer), and a breaker tripping signal is directly output to a breaker executing mechanism through the hard wiring.
In a possible implementation manner, the master station may be set in a hub substation of a regional power grid, the master station is configured to collect device information of the whole grid and perform a centralized decision, the slave station may be set in a substation or a power plant in the regional power grid, the substation is in charge of collecting device information in the substation or the power plant, for example, voltage, current, and the like, and the slave station is also in charge of executing an instruction sent by the master station. The system of the embodiment of the invention can comprise a plurality of different substations which are respectively responsible for collecting the equipment electrical state information of the transformer substations or the power plants in different power supply areas.
In a possible implementation, a developer can pre-select and set the breakers that are likely to be disconnected, i.e. the first type of breakers (breakers disconnected by devices other than the power supply network rapid reconfiguration system, such as a relay protection or stability control device) and the second type of breakers (breakers disconnected by the power supply network rapid reconfiguration system itself), which need to be monitored, and the restoration networking breakers associated with the breakers (i.e. the breakers that are likely to be disconnected), according to the analysis of the power supply network; the system can record the association between the circuit breakers that are likely to open and the recovery networking circuit breakers associated therewith; when the system monitors that the circuit breaker which is likely to be disconnected is disconnected, the associated recovery networking circuit breaker can be obtained according to the association relation, and the associated recovery networking circuit breaker is controlled to be rapidly switched on. In another possible implementation, the system can also perform real-time network topology analysis of the power supply network in the master station based on the state of the circuit breaker, determine on-line the circuit breaker which needs to be monitored and is likely to be opened and the recovery network circuit breaker associated with the circuit breaker, and control the action of the circuit breaker according to the real-time monitored information.
Fig. 2 shows a flowchart of a method for fast reconstruction of a power supply network after a power grid fault according to an embodiment of the present invention, where the method can be applied to a master station and a slave station in the system of fig. 1, and specifically includes the following steps:
step 1: the fast reconstruction master station collects all state information of a monitored power grid (also called controlled power grid) from a substation located in a transformer substation or a power plant, compares the state information with built-in characteristics of a fault set which possibly occurs, and judges whether a breaker of the monitored power grid is disconnected or a disconnection fault which causes the breaker to be disconnected occurs, namely, the real-time perception of the disconnection fault of the power grid is carried out;
the fast reconstruction substation acquires and measures electrical information in a plant station through hard wiring, uploads substation measurement information and local decision information to the main station through network communication and receives a switching-on pre-starting signal and a switching-on signal transmitted by the main station; and the quick reconstruction substation judges the trigger logic of the on-site circuit breaker and the synchronous closing logic of the circuit breaker, and gives closing or tripping signals to the circuit breaker through hard wiring.
The fast reconstruction main station collects information of key equipment in the power grid measured by each plant station from each substation through a communication network, performs centralized analysis and decision making, and then issues an active splitting signal, a closing pre-starting signal and a closing signal to each substation. In addition, the main station also has the function of quickly reconstructing the substation of the station.
The following requirements are provided for information acquisition and transmission of the fast reconstruction master station and the fast reconstruction substation:
s2-1) the quick reconstruction substation acquires and measures the electrical information in the plant station through hard wiring;
s2-2) rapidly reconstructing the transmission of information and instructions between the master station and the substation through network communication; for example, 2M private communication network is adopted;
s2-3) rapidly reconstructing the power frequency wave recording data sampling rate of the substation to be not less than 1200 Hz;
s2-4) rapidly reconstructing the substation data, wherein the calculation processing period is not more than 0.83 ms;
s2-5) quickly reconstructing the information transmission period and the instruction scanning period between the master station and the substation, which are not more than 1.67 ms;
s2-6) rapidly reconstructing switching values collected by the substation at the substation or the power plant comprises the following steps: the position of the circuit breaker, a protection trip signal and a trip signal of the stability control device;
s2-7) the analog quantity collected by the quick reconstruction substation in the transformer substation or the power plant comprises the following steps: the voltage of the key bus, the current and the voltage of an external power line, a transformer branch, a generator branch, an inter-station tie line or a bus tie. Among the faults that will cause the circuit breaker to open include, but are not limited to, the following:
s3-1) short-circuit fault;
s3-2) overcurrent fault;
s3-3) a power or voltage oscillation fault;
s3-4) the outer net is remotely split to form an isolated net.
The circuit breakers disconnected by the non-power-supply-network rapid reconstruction system are called as such circuit breakers disconnected by the relay protection device, the power grid stability control device and other devices, and the circuit breaker of the island power grid without the original fault after the circuit breaker is disconnected is a first type of circuit breaker.
When the outer network is remotely disconnected to form an isolated network, the monitored power grid and the outer network are actively disconnected at a tie line breaker by the power supply network rapid reconstruction system, and the monitored power grid forms an isolated island.
Step 2: when the master station monitors that a preset fault which possibly causes the circuit breaker to be switched off occurs, the master station sends a closing pre-starting signal to a substation where a plurality of recovery networking circuit breakers corresponding to the circuit breaker which is possibly switched off, namely a first type of circuit breaker, are located;
the method for monitoring the preset fault which may cause the breaker to be disconnected comprises the following steps:
s4-1) rapidly reconstructing the main station to evaluate the voltage of each bus in the monitored power grid in real time, and when the lowest bus voltage is lower than a first voltage threshold and lasts for a first time period threshold, selecting the bus corresponding to the lowest bus voltage as a fault bus; the present invention preferably has a first voltage threshold of 0.5 times the nominal voltage and a first time period threshold of 10 ms.
S4-2) selecting the branch with the largest current as a fault branch according to the magnitude of the current of each branch connected with the fault bus, and selecting the circuit breaker close to the fault bus on the fault branch as a first-class circuit breaker;
s4-3) if the fault occurs on the bus, determining a first type breaker by adopting the method of S4-2.
Wherein the recovery networking breaker has the following characteristics:
s5-1) the recovery networking circuit breaker can connect the island power grid with other power grids through switching-on operation;
s5-2) after the networking circuit breaker is recovered to be switched on, the overcurrent protection action is not triggered within a second time period threshold value, and the second time period threshold value is preferably 20S. (ii) a
S5-3) if there are a plurality of recovery networking breakers for an island formed by a certain first type breaker or second type breaker and these recovery networking breakers belong to three or more voltage classes, only the recovery networking breaker of the highest two voltage classes is reserved.
S5-4) each recovery networking breaker belongs to a quick reconstruction substation, and the instruction sent by the main station to the recovery networking breaker is forwarded through the quick reconstruction substation.
Fig. 3 shows a schematic diagram of the rapid reconfiguration of the power supply network in the event of a fault in the local network. As shown in fig. 3, when a 4# step-down branch circuit breaker in the regional power grid fails and a breaker trips in 304 for protection, the method according to the present invention should select a fast-closing recovery networking breaker as: 3200 buscouple of 35kV, 6101 buscouple of 6kV, 6102 buscouple and 6103 buscouple. The 6kV bus coupler is far away from the fault and has a large number of motor loads, so that the phase angle difference between the 6kV buses is usually smaller than that between the 35kV buses, and the synchronous closing success rate of the bus coupler is high; in addition, the reason for simultaneously selecting 3 6kV bus-coupled switches is as follows: when the 3200 bus coupler is not switched on successfully, if the fast switching-on is realized by only using 16 kV bus coupler, for example, a 6101 circuit breaker is switched on, the 35kV III section supplies power to three groups of loads of the 35kV IV section through 2# and 1# transformers, and the transformers are likely to be overloaded, so that 3 6kV bus couplers are adopted to participate in the fast switching-on simultaneously, and the possibility of the overload of each 35/6kV transformer can be reduced.
In fact, because the distance between each bus and a fault point is different due to different motor loads or generators, the voltage amplitude and phase angle change conditions are different, the synchronous switching-on condition of fast switching is not met between a certain pair of buses, and the synchronous switching-on condition is probably met between other buses, so that the success rate of fast switching can be improved by simultaneously carrying out fast switching attempts on power supplies among different buses.
And step 3: if the main station monitors that the outer network has a (island) disconnection fault and breaks down, the main station disconnects an outer network connection breaker, namely a second type breaker, and simultaneously sends synchronous detection closing signals to the substation where a plurality of recovery networking breakers corresponding to the second type breaker are located;
the method comprises the following steps that an island disconnection fault of an external network is determined, and the external network is broken down and needs to meet all the following criteria at the same time:
s6-1) the frequency deviation of the bus connected with the external network interconnection line exceeds a first frequency deviation threshold value from the rated frequency (50 Hz); the first frequency deviation threshold value is preferably 0.1 Hz;
s6-2) the frequency deviation of the bus connected with the external network interconnection line and the bus frequency of the standby power supply area exceeds a second frequency deviation threshold value; the second frequency deviation threshold value is preferably 0.2 Hz;
s6-3) the frequency of the bus in the spare power supply area is within a first frequency range; the first frequency range is preferably 49 Hz-51 Hz;
s6-4) the frequency change rate of the bus connected with the external network interconnection line exceeds a first frequency change rate threshold value; the first frequency change threshold value is preferably 0.2 Hz/s;
s6-5) the above conditions are all satisfied, and the duration is greater than a third time period threshold; the present invention preferably has the third time period threshold of 150 ms.
When the main station monitors that the outer network has an island disconnection fault and breaks down in step 3, the following signals are sent:
s8-1) the master station sends a tripping signal to an external network interconnection breaker, namely a second type breaker;
s8-2) delaying for 5 milliseconds, and sending a synchronous detection closing signal to the substation where the plurality of recovery networking circuit breakers corresponding to the second type of circuit breaker are located.
The requirements for restoring the networked breakers in step 3 are the same as in step 2.
When a remote system external fault (external network collapse) occurs in a power grid, an area monitored by a conventional power supply quick switching device has no switching action, the quick switching device cannot be started, but the frequency and the voltage are collapsing.
Fig. 4 shows a schematic diagram of the fast reconfiguration of the power supply network in the event of a remote disconnection fault of the external network. As shown in fig. 4, a remote fault on the external grid JJN causes a remote breaker to trip, which results in the disconnection of the JJN external grid from the large grid and the formation of a large-scale island grid with the regional grid, but because the 112 tie switch is not open, the conventional power source fast switching device cannot be started, and the island grid cannot be reconnected to the normally-supplied XJZ external grid through the quick connection of the 100 breaker. The method can actively disconnect 112 circuit breakers under the condition of an external network island, thereby triggering the rapid switching of the power supply, then selecting a 100 bus coupler with a rapid switching 110kV voltage grade and a 3000 bus coupler with a 35kV voltage grade, and rapidly switching on the regional power grid of the island to an XJZ power grid, wherein the switching can be completed within 150ms, so that the island can be eliminated under the condition that the load keeps continuous operation. Both simulation and actual measurement show that under the condition of an external network fault, at the same moment, the 110kV bus connection is close to the fault, so that the phase angle difference between 110kV buses is usually larger than that between 35kV buses, and the probability of successful synchronous closing detection of a 3000 circuit breaker is higher than that of a 100 circuit breaker.
And 4, step 4: the substation receiving the switching-on pre-starting signal identifies the fault clearing time in real time according to the local measurement information, and immediately or after a specified time, sends a synchronous detection switching-on signal to a recovery networking circuit breaker corresponding to the first type of circuit breaker when finding that the fault is cleared or is being cleared; the faults and the first-type circuit breakers are not limited to the plant station where the substation is located, and the faults and the first-type circuit breakers of other remote plant stations are also included.
In step 4, the substation receiving the closing pre-start signal identifies the time when the fault is cleared or is being cleared by adopting the following method, and sends a closing signal in the detection period to the corresponding recovery networking circuit breaker (in the plant station where the fast reconstruction substation is located):
s10-1) if the substation and the first type of circuit breaker are in the same station, the substation directly receives a tripping signal of the first type of circuit breaker through hard wiring, and after receiving the tripping signal, the substation immediately sends a synchronous detection closing signal to a recovery networking circuit breaker corresponding to the first type of circuit breaker;
s10-2) if the sub-station and the first type of circuit breaker are in the same station, the sub-station directly receives a tripping exit signal sent by an automatic device such as a protection device or a stability control device related to the first type of circuit breaker through hard wiring; after receiving the tripping exit signal, the substation delays a fourth time period threshold value to send a synchronous detection closing signal to a recovery networking circuit breaker corresponding to the first type of circuit breaker; the invention preferably selects the fourth time period threshold value as 5 ms;
s10-3) if the sub-station and the first-type circuit breaker are not in the same station, the sub-station judges the moment when the fault is cleared through the state of the voltage at two ends of the circuit breaker receiving the closing pre-starting signal in the monitoring station; and when the fault is cleared, the substation immediately sends a synchronous closing detection signal to the recovery networking circuit breaker corresponding to the first type of circuit breaker.
The specific method for judging the moment when the fault is cleared according to the state of the voltage at two ends of the circuit breaker is as follows:
s11-1) the substation monitors the bus voltage Uy at the lower side of the voltage in the buses at the two sides connected with the circuit breaker receiving the closing pre-starting signal in real time;
s11-2) when Uy is greater than 0.9 times the rated voltage or the voltage rises more than 0.1 times the rated voltage within 20ms, the fault is considered to be cleared, and the time is recorded as the clearing time when the fault is cleared.
The term "immediately" in the present invention means that the delay from the time when the substation receives the occurrence of the opening of the first type breaker should not exceed 5 ms.
For the situation shown in fig. 3, when the 4# step-down transformer branch is short-circuited, the main station of the 110kV/35kV substation triggers the substation located in the 35kV/6kV distribution substation in advance, and when the substation monitors the voltage recovery of the 6kV I-segment, it indicates that the 304 switch has been protected and tripped, so that the operation of quickly switching on the 6kV bus coupler can be performed, a switching-on signal sent by the main station is not required, communication time of several milliseconds is saved, and the satisfaction of synchronous switching-on conditions in the subsequent step 6 is facilitated.
And 5: the master station monitors the on-off signals of the first-class circuit breakers in the whole network range in real time, and when a certain first-class circuit breaker is found to be on or being on, the master station immediately or with a specified time delay sends a backup detection synchronous closing signal to a plurality of recovery networking circuit breakers corresponding to the first-class circuit breakers. The specific method comprises the following steps:
s12-1) the master station receives the on-off signals of all first-class circuit breakers or the tripping signals of protection devices or stability control devices associated with the first-class circuit breakers in the whole network range from the substation through a communication network in real time;
s12-2) the main station receives the on-off signal of each first type of circuit breaker in the plant station or the trip signal of a protection device or a stable control device associated with the first type of circuit breaker in real time through hard wiring;
s12-3) when the master station monitors that a certain first type of circuit breaker is disconnected, the master station immediately sends synchronous closing detection signals to the substations of a plurality of recovery networking circuit breakers corresponding to the first type of circuit breaker through a communication network, and the recovery networking circuit breakers can belong to different control substations or plant stations;
s12-4) when the main station monitors that the protection or stability control device sends a tripping signal to a certain first type of circuit breaker, 5ms of delay time sends synchronous closing detection signals to the substation of a plurality of recovery networking circuit breakers corresponding to the first type of circuit breaker through a communication network, and the recovery networking circuit breakers can belong to different control substations or plant stations. When a tripping outlet signal of a protection device or an automatic device is used as a trigger signal for detecting synchronous switching-on, the circuit breaker of a fault power grid is ensured to break the fault first and then switch on the standby power supply circuit breaker through a certain time delay, so that the phenomenon that the standby power supply is switched on the fault due to the fact that the circuit breaker of the fault power grid is not completely broken and the fault range is expanded is avoided.
S12-5) when the sub-station sends out the synchronous closing detection signal and the synchronous closing detection signal sent by the sub-station is executed, the synchronous closing detection signal of the main station is ignored; otherwise, executing a synchronous closing detection signal of the master station; namely, the detection synchronization closing signal of the main station is a backup signal of the detection synchronization closing signal of the sub station.
The term "immediately" in the present invention means that the delay from the time when the master station receives the occurrence of the opening of the first type of circuit breaker should not exceed 5 ms.
For example, when receiving the following signals, the fast reconfiguration master station transmits a fast closing signal to the control substation of the associated closing circuit breaker through the following corresponding set delays:
(5.1) the main station in-situ station breaker tripping signal has no time delay;
(5.2) delaying for 30ms by a trip exit signal sent by a protection or automatic device associated with a circuit breaker in the main station local station or a trip exit signal sent by an active splitting module of the reconstruction main station;
(5.3) a remote station circuit breaker tripping signal is not delayed;
(5.4) delaying for 10ms by a tripping outlet signal sent by a protection or automatic device associated with a circuit breaker in a remote station;
when receiving the following signals, the fast reconstruction substation sends a fast closing signal to a local substation control module of an associated closing circuit breaker through the following corresponding set time delay:
(5.5) rapidly reconstructing a rapid switching-on signal sent by the master station to the substation without time delay;
(5.6) rapidly reconstructing a trip signal of a circuit breaker in the substation in the site without time delay;
(5.7) rapidly reconstructing a trip exit signal sent by a protection or automatic device associated with a circuit breaker in the substation or a trip exit signal sent by an active splitting module of the main reconstruction station, and delaying for 30 ms;
(5.8) if the fast reconfiguration sub-station receives a switching-on pre-triggering instruction for a certain circuit breaker in the step 3, the fast reconfiguration sub-station monitors the bus with the lower voltage in the buses on the two sides connected with the circuit breaker in real time, and when the voltage of the bus is greater than 0.9 times of rated voltage or the voltage rises to exceed 0.1 times of rated voltage within 20ms, the fast reconfiguration sub-station sends a fast switching-on signal to a control module of the circuit breaker without delay.
Because the complete disconnection of the circuit breaker requires tens of milliseconds, a tripping outlet signal of a protection or automatic device is used as a trigger signal for rapid switching-on, and the fault power grid circuit breaker is firstly disconnected and then switched on by a standby power supply circuit breaker through certain time delay.
For the situation shown in fig. 3, when the 4# step-down transformer branch is short-circuited, the master station of the 110kV/35kV substation triggers the substation located in the 35kV/6kV distribution substation in advance, and when the substation does not successfully judge 304 to trip, the closing signal remotely sent by the master station becomes a backup remedy.
Step 6: and (4) checking synchronization and locking execution of synchronous closing. Whether the two sides of the switched-on recovery networking circuit breaker meet the synchronous switching-on condition and whether the in-zone fault locking and the standby power supply fault locking do not exist is checked, and if the requirements are met, a switching-on execution signal is sent to the recovery networking circuit breaker.
The synchronous closing condition of the recovery networking circuit breaker meets the following requirements at the same time:
s15-1) recovering the phase angle difference of the voltages at the two sides of the networked circuit breaker to be less than 20 degrees;
s15-2) recovering the frequency difference of the two sides of the networked circuit breaker to be less than 1 Hz;
s15-3) restoring the difference of the voltage auxiliary values at the two sides of the networked circuit breaker to be less than 0.2 times of the rated voltage.
Restoring the node voltage of the networked circuit breaker on the island region side to meet any one of the following conditions, and then generating the intra-region fault locking of the circuit breaker:
s16-1) the existing phase voltages are all less than 0.7 times of rated voltage;
s16-2) in the three-phase voltage amplitude, the difference between the maximum value and the minimum value is more than 30%.
The voltage and the frequency of the nodes of the recovery networking circuit breaker on the side of the standby power supply meet any one of the following conditions, and then the standby power supply fault locking of the recovery networking circuit breaker is generated:
s17-1) the phase voltage is out of the range of 0.85-1.2 times of the rated value;
s17-2) frequency is out of the range of 49.2 Hz-50.8 Hz.
And 7: and after the power grid is interconnected, disconnecting the overcurrent recovery networking circuit breaker or limiting the current. The method comprises the following steps: if the current of the circuit breaker exceeds the allowable current threshold value after the networking circuit breaker is restored to be switched on and lasts for more than the threshold value of the fifth time period, the circuit breaker is switched off or a quick switch corresponding to the substation is triggered to enter a high-impedance state; the present invention preferably has the fifth time period threshold value of 100 ms.
The overcurrent quick-break can be realized in the quick reconstruction device; if the over-current limiting scheme is adopted, a fast switch needs to be additionally arranged, and when the current of the switch is larger than a certain fixed value, the reactance of the switch is changed from 0 to a large value, so that the purpose of limiting the current is achieved.
And 8: the method for unlocking the existing high-low voltage electromagnetic looped network comprises the following steps:
19-1) after the closing execution signal is sent out in the step 6, if the first type of circuit breaker and the second type of circuit breaker which should trip are still in a closing state and continue for a sixth time period threshold, sending a tripping instruction to the circuit breakers; the sixth time period threshold value is preferably 150 ms;
19-2) after the closing execution signal is sent out in the step 6, if the recovery networking circuit breakers of the high voltage class are in a closing success state and continue for a sixth time period threshold, a tripping instruction is sent out to all recovery networking circuit breakers of the lower voltage class which are successfully closed; the present invention preferably has the sixth time period threshold of 150 ms.
It should be noted that the selected circuit breakers are not opened if the following conditions are met, and the selection of the circuit breakers not involved in opening can be realized by offline setting or online topology analysis:
19-3) if the cut-off of the low-voltage circuit breaker reduces the access amount of the external power supply, not tripping the low-voltage circuit breaker;
19-4) if the external network is a single power supply, it is impossible to form a high-low voltage electromagnetic ring network in which the external network power crosses the power grid in the region.
For the case of fig. 3, after the closing execution signal is sent, if the 3200 circuit breaker of 35kV is detected to be successfully closed and lasts for 150ms, the 6101, 6102 and 6103 circuit breakers of 6kV are opened.
In the case of fig. 4, after the closing execution signal is sent, if it is checked that the 100 circuit breaker of 110kV is successfully closed and lasts for 150ms, the 3000 circuit breaker of 35kV is opened.
And step 9: and resetting the power supply network quick reconstruction system. And (5) resetting each device of the power supply network rapid reconstruction system 200ms after the step 8 is finished, and returning to the step 1 to monitor the next power grid splitting event.
By adopting the method, the grid connection of the separated isolated network can be recovered within the longest 150ms after the power grid is separated, so that the normal grid connection operation of the motor load can be recovered in a non-stop state after the power failure.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (26)

1. A method for the millisecond-level fast reconstruction of a power supply network after a power grid fault is characterized by comprising the following characteristic steps:
step 1: the fast reconstruction master station collects all state information of the monitored power grid from the fast reconstruction substation positioned in the transformer substation or the power plant, compares the state information with built-in fault set characteristics which possibly occur, and judges whether the monitored power grid has a breaker or a fault which causes the breaker to be disconnected, namely, carries out real-time perception of the power grid disconnection fault;
step 2: when the rapid reconstruction master station monitors that a preset fault which possibly causes the circuit breaker to be disconnected occurs, sending a closing pre-starting signal to a rapid reconstruction substation where a plurality of recovery networking circuit breakers corresponding to a first type of circuit breaker are located, wherein the first type of circuit breaker can be the circuit breaker which can be disconnected;
and step 3: if the fast reconstruction master station monitors that the outer network has a disconnection fault and is broken down, disconnecting a second type of circuit breaker, and simultaneously sending a synchronous detection closing signal to a fast reconstruction substation where a plurality of recovery networking circuit breakers corresponding to the second type of circuit breaker are located, wherein the second type of circuit breaker is an outer network interconnection circuit breaker;
and 4, step 4: the fast reconstruction substation receiving the closing pre-starting signal identifies the fault clearing time in real time according to the local measurement information, and immediately or with specified time delay sends a synchronous closing detection signal to the recovery networking circuit breaker corresponding to the first type of circuit breaker when finding that the fault is cleared or is being cleared;
and 5: the method comprises the steps that a rapid reconstruction master station monitors the on-off signals of first-class circuit breakers in a whole network range in real time, and when one first-class circuit breaker is found to be on or being on, a backup detection synchronous closing signal is sent to a plurality of recovery networking circuit breakers corresponding to the first-class circuit breakers immediately or in a specified time delay mode;
step 6: checking synchronization and locking execution of synchronous closing: checking whether two sides of the switched-on recovery networking circuit breaker meet synchronous switching-on conditions or not and whether in-zone fault locking does not exist or not and standby power supply fault locking does not exist, and if the two sides of the switched-on recovery networking circuit breaker meet the requirements, sending a switching-on execution signal to the recovery networking circuit breaker;
and 7: after the power grid is interconnected, disconnecting the overcurrent recovery networking circuit breaker or limiting the current;
and 8: unfastening the existing high-low voltage electromagnetic looped network;
and step 9: resetting of the power supply network rapid reconfiguration system: and (5) resetting each device of the power supply network rapid reconstruction system 200ms after the step 8 is finished, and returning to the step 1 to monitor the next power grid splitting event.
2. The method for quickly reconstructing millisecond-level power supply network after power grid fault according to claim 1, wherein the following requirements are placed on information acquisition and transmission of the quickly reconstructing main station and the quickly reconstructing sub-station in the step 1:
s2-1) the quick reconstruction substation acquires and measures the electrical information in the plant station through hard wiring;
s2-2) information and instruction transmission is carried out between the quick reconstruction master station and the quick reconstruction substation through network communication;
s2-3) rapidly reconstructing the power frequency wave recording data sampling rate of the substation to be not less than 1200 Hz;
s2-4) rapidly reconstructing the substation data, wherein the calculation processing period is not more than 0.83 ms;
s2-5) the information transmission period and the instruction scanning period between the quick reconstruction master station and the quick reconstruction substation are not more than 1.67 ms;
s2-6) rapidly reconstructing switching values collected by the substation at the substation or the power plant comprises the following steps: the position of the circuit breaker, a protection trip signal and a trip signal of the stability control device;
s2-7) the analog quantity collected by the quick reconstruction substation in the transformer substation or the power plant comprises the following steps: the voltage of the key bus, the current and the voltage of an external power line, a transformer branch, a generator branch, an inter-station tie line or a bus tie.
3. A power supply network millisecond-level rapid reconstruction method after the grid fault is carried out according to claim 1, wherein in the step 1, whether a breaker is disconnected or a fault which will cause the breaker to be disconnected occurs is judged according to the collected grid information at the rapid reconstruction master station, wherein the fault which will cause the breaker to be disconnected comprises the following faults:
s3-1) short-circuit fault;
s3-2) overcurrent fault;
s3-3) a power or voltage oscillation fault;
s3-4) remotely splitting the outer net to form an isolated net;
wherein, short-circuit fault, overcurrent fault, power or voltage oscillation trouble will trigger the corresponding first class circuit breaker of device disconnection outside the quick reconsitution system of power supply network, cause the electric wire netting to separate out and form the isolated island, and can appear an isolated island electric wire netting that does not contain original trouble after the disconnection, the device outside the quick reconsitution system of power supply network includes: relay protection and power grid stability control devices;
when the outer network is remotely disconnected to form an isolated network, the monitored power grid and the outer network are actively disconnected at a tie line breaker, namely a second type breaker by the power supply network rapid reconstruction system, and the monitored power grid forms an isolated island.
4. A method for millisecond-level fast reconstruction of a power supply network after a grid fault according to claim 1, wherein the method for monitoring the preset fault which may cause the breaker to open in the step 2 is as follows:
s4-1) rapidly reconstructing the main station to evaluate the voltage of each bus in the monitored power grid in real time, and when the lowest bus voltage is lower than a first voltage threshold and lasts for a first time period threshold, selecting the bus corresponding to the lowest bus voltage as a fault bus;
s4-2) selecting the branch with the largest current as a fault branch according to the magnitude of the current of each branch connected with the fault bus, and selecting the circuit breaker close to the fault bus on the fault branch as a first-class circuit breaker;
s4-3) if the fault occurs on the bus, determining a first type breaker by adopting the method S4-2).
5. A method for the millisecond-level fast reconfiguration of a supply network after a grid fault according to claim 1, wherein the recovery networking breakers in steps 2 and 3 have the following characteristics:
s5-1) the recovery networking circuit breaker connects the island power grid with other power grids through switching-on operation;
s5-2) after the networking circuit breaker is recovered to be switched on, the overcurrent protection action is not triggered within a second time period threshold value;
s5-3) if a plurality of recovery networking circuit breakers exist in an island formed by a certain first type circuit breaker or a certain second type circuit breaker, and the recovery networking circuit breakers belong to more than two voltage classes, only the recovery networking circuit breaker with the highest two voltage classes is reserved;
s5-4) each recovery networking breaker belongs to a quick reconstruction substation, and the instruction sent by the main station to the recovery networking breaker is forwarded through the quick reconstruction substation.
6. A method for millisecond-level fast reconstruction of a power supply network after a grid fault according to claim 1, wherein in step 3, all the following criteria are simultaneously satisfied to determine that the external grid has a disconnection fault and has crashed:
s6-1) the frequency deviation of the bus connected with the external network interconnection line exceeds a first frequency deviation threshold value from the rated frequency;
s6-2) the frequency deviation of the bus connected with the external network interconnection line and the bus frequency of the standby power supply area exceeds a second frequency deviation threshold value;
s6-3) the frequency of the bus in the spare power supply area is within a first frequency range;
s6-4) the frequency change rate of the bus connected with the external network interconnection line exceeds a first frequency change rate threshold value;
s6-5) the above conditions are all satisfied and the duration is greater than the third time period threshold.
7. The method for rapidly reconstructing the millisecond level of the power supply network after the power grid fault according to claim 1, wherein when the rapid reconstruction master station monitors that a preset fault occurs in the step 2, before the circuit breaker is disconnected due to the preset fault, a switching-on pre-starting signal is sent to a substation where a plurality of recovery networking circuit breakers are located.
8. A method for millisecond-level fast reconstruction of a power supply network after a grid fault according to claim 1, wherein when the fast reconstruction master station monitors that the outer grid has a disconnection fault and has crashed in step 3, the following signals are sent:
s8-1) sending a tripping signal to an external network connection breaker, namely a second type breaker;
s8-2) delaying for 5 milliseconds, and sending a synchronous detection closing signal to the substation where the plurality of recovery networking circuit breakers corresponding to the second type of circuit breaker are located.
9. The method for quickly reconstructing the millisecond level of the power supply network after the power grid fault according to claim 1, wherein when the fast reconstruction substation receiving the closing pre-starting signal in the step 4 identifies that the fault is cleared or is being cleared in real time according to the local measurement information, namely when the first type of circuit breaker is disconnected or is being disconnected, the fast reconstruction substation sends a synchronous closing detection signal to a recovery networking circuit breaker in a plant station where the fast reconstruction substation is located, wherein the fault and the first type of circuit breaker are not limited to the plant station where the fast reconstruction substation is located, and the fault and the first type of circuit breaker of other remote plant stations are included.
10. A power supply network millisecond-level fast reconstruction method after the grid fault according to claim 1, wherein the fast reconstruction substation receiving the closing pre-starting signal in the step 4 adopts the following method to identify that the fault is cleared or is being cleared:
s10-1) if the quick reconstruction substation is in the same station as the first type of circuit breaker, the quick reconstruction substation directly receives a tripping signal of the first type of circuit breaker through a hard wire, and after receiving the tripping signal, the quick reconstruction substation immediately sends a synchronous closing detection signal to a recovery networking circuit breaker corresponding to the first type of circuit breaker;
s10-2) if the fast reconstruction substation and the first type of circuit breaker are in the same station, the fast reconstruction substation directly receives a tripping exit signal sent by a protection device or a stability control device related to the first type of circuit breaker through hard wiring; after receiving a tripping exit signal, the quick reconstruction substation delays a fourth time period threshold value to send a synchronous detection closing signal to a recovery networking circuit breaker corresponding to the first type of circuit breaker;
s10-3) if the quick reconstruction substation is not in the same station as the first-type circuit breaker, the quick reconstruction substation judges the moment when the fault is cleared through the state of the voltage at two ends of the circuit breaker receiving the closing pre-starting signal in the monitoring station; and when the fault is cleared, the quick reconstruction substation immediately sends a synchronous closing detection signal to the recovery networking circuit breaker corresponding to the first type of circuit breaker.
11. A method for rapid reconstruction of the millisecond level of a power supply network after a grid fault according to claim 10, wherein S10-3) identifies the moment when the fault is cleared by the following method:
s11-1) the fast reconstruction substation monitors the bus voltage U with lower voltage in the buses at two sides connected with the breaker receiving the closing pre-starting signal in real timey；
S11-2) when U is presentyGreater than 0.9 times rated voltage or voltage rise of more than 0.1 times within 20msWhen the voltage is fixed, the fault is considered to be cleared, and the moment is recorded as the moment when the fault is cleared.
12. A method for quickly reconstructing millisecond level of a power supply network after a power grid fault according to claim 1, wherein in the step 5, the method for the quick reconstruction master station to monitor the on/off of the first type of circuit breaker and send a backup detection synchronous closing signal comprises the following steps:
s12-1) the fast reconstruction master station receives the on-off signals of all first-class circuit breakers or the tripping signals of protection devices or stability control devices associated with the first-class circuit breakers in the whole network range in real time from the fast reconstruction substation through a communication network;
s12-2) the fast reconstruction master station receives the on-off signal of each first type of circuit breaker in the plant station or the trip signal of a protection device or a stable control device associated with the first type of circuit breaker in real time through hard wiring;
s12-3) when the rapid reconstruction master station monitors that a certain first type of circuit breaker is disconnected, instantly sending synchronous closing detection signals to rapid reconstruction substations of a plurality of recovery networking circuit breakers corresponding to the first type of circuit breaker through a communication network, wherein the recovery networking circuit breakers can belong to different rapid reconstruction substations or plant stations;
s12-4) when the fast reconstruction master station monitors that the protection device or the stable control device sends a tripping signal to a certain first type of circuit breaker, 5ms of delay is carried out to send synchronous closing detection signals to fast reconstruction substations of a plurality of recovery networking circuit breakers corresponding to the first type of circuit breaker through a communication network, and the recovery networking circuit breakers can belong to different fast reconstruction substations or plant stations;
s12-5) when the rapid reconstruction substation sends out a synchronization detection closing signal and the synchronization detection closing signal sent by the rapid reconstruction substation is executed, the synchronization detection closing signal of the rapid reconstruction main station is ignored; otherwise, quickly reconstructing the detection synchronization closing signal of the main station; namely, the detection synchronization closing signal of the fast reconstruction main station is a backup signal of the detection synchronization closing signal of the fast reconstruction substation.
13. A method for millisecond-level fast reconstruction of a power supply network after a power grid fault according to claim 1, wherein when the first type breaker is found to be disconnected in steps 4 and 5, a synchronous closing detection signal is immediately sent to the corresponding recovery networking breaker, and the "immediate" time delay relative to the time when the fast reconstruction substation or the fast reconstruction master station receives the disconnection occurrence time of the first type breaker is not more than 5 ms.
14. The method for quickly reconstructing the millisecond level of the power supply network after the power grid fault is provided according to claim 1, wherein in the step 6, the quick reconstruction substation of the recovery networking circuit breaker which receives the synchronous closing detection signal judges whether the recovery networking circuit breaker simultaneously meets synchronous closing conditions, no intra-area fault blocking and no standby power supply fault blocking, and if so, a closing execution signal is sent to the recovery networking circuit breaker.
15. The method for rapidly reconstructing millisecond-level power supply network after grid fault according to claim 1 or 14, wherein in the synchronization detection method in the step 6, the synchronization closing condition for recovering the networked circuit breakers simultaneously meets the following requirements:
s15-1) recovering the phase angle difference of the voltages at the two sides of the networked circuit breaker to be less than 20 degrees;
s15-2) recovering the frequency difference of the two sides of the networked circuit breaker to be less than 1 Hz;
s15-3) restoring the difference of the voltage auxiliary values at the two sides of the networked circuit breaker to be less than 0.2 times of the rated voltage.
16. A method for fast reconstruction of millisecond level of a power supply network after a grid fault according to claim 1 or 14, wherein the blocking of the intra-zone fault in the step 6 means that the blocking of the intra-zone fault of the recovery networked circuit breaker is generated when the node voltage of the recovery networked circuit breaker on the island region side meets any one of the following conditions:
s16-1) the existing phase voltages are all less than 0.7 times of rated voltage;
s16-2) in the three-phase voltage amplitude, the difference between the maximum value and the minimum value is larger than 30% of rated voltage.
17. A method for fast reconstruction of a power supply network millisecond after a power grid fault according to claim 1 or 14, wherein the backup power source fault blocking in the step 6 means that the backup power source fault blocking of the recovery networked circuit breaker is generated when the node voltage and frequency of the recovery networked circuit breaker on the backup power source side meet any one of the following conditions:
s17-1) the phase voltage is out of the range of 0.85-1.2 times of the rated value;
s17-2) frequency is out of the range of 49.2 Hz-50.8 Hz.
18. A method for millisecond-level fast reconstruction of a power supply network after a grid fault according to claim 1, wherein in step 7, the overcurrent recovery network breaker is opened or current limiting is performed by the following method: and if the current of the circuit breaker exceeds the allowable current threshold value after the networking circuit breaker is restored to be switched on and lasts for more than the threshold value of the fifth time period, the circuit breaker is switched off or the quick switch corresponding to the quick reconstruction substation is triggered to enter a high-impedance state.
19. A method for millisecond-level fast reconstruction of a power supply network after a grid fault according to claim 1, wherein in step 8, the high-low voltage electromagnetic ring network is untied by adopting the following method:
19-1) after the closing execution signal is sent out in the step 6, if the first type of circuit breaker and the second type of circuit breaker which should trip are still in a closing state and continue for a sixth time period threshold, sending a tripping instruction to the circuit breakers;
19-2) after the closing execution signal is sent out in the step 6, if the recovery networking circuit breakers of the high voltage class are in a closing success state and continue for a sixth time period threshold, a tripping instruction is sent out to all recovery networking circuit breakers of the lower voltage class which are successfully closed;
it should be noted that the selected circuit breakers are not opened if the following conditions are met, and the selection of the circuit breakers not involved in opening can be realized by offline setting or online topology analysis:
19-3) if the cut-off of the low-voltage circuit breaker reduces the access amount of the external power supply, not tripping the low-voltage circuit breaker;
19-4) if the external network is a single power supply, it is impossible to form a high-low voltage electromagnetic ring network in which the external network power crosses the power grid in the region.
20. The method for rapidly reconstructing millisecond-level power supply network after grid fault according to claim 1, wherein after the grid is disconnected, the grid connection of the disconnected grid is recovered within the longest 150 ms.
21. A method for supply network millisecond rapid reconfiguration after a grid fault according to claim 4, wherein the first voltage threshold is set to 0.5 times the rated voltage and the first time period threshold is set to 10 ms.
22. A method for supply network millisecond quick reconstruction after grid fault according to claim 5, wherein the second time period threshold is set to 20 s.
23. A power supply network millisecond-level rapid reconstruction method after the grid fault according to claim 6, wherein the method comprises the following steps: the first frequency deviation threshold value is 0.1Hz, the second frequency deviation threshold value is 0.2Hz, the first frequency range is 49 Hz-51 Hz, the first frequency change threshold value is 0.2Hz/s, and the third time period threshold value is 150 ms.
24. A method as claimed in claim 10, wherein the fourth time period threshold is 5 ms.
25. A method according to claim 18, wherein the fifth time period threshold is 100 ms.
26. A method according to claim 19, wherein the sixth time period threshold is 150 ms.
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