Power distribution network fault and load control method and device based on master-slave coordination and medium

Abstract

The application provides a power distribution network fault and load control method based on main distribution coordination, real-time monitoring of power distribution network data by an intelligent power distribution terminal, including power distribution network operation state, protection action signal, and operation parameters of a distributed unit and a microgrid; then the intelligent power distribution terminal comprehensively researches and judges system state based on the real-time monitored power distribution network data, determines three types of scenes, the three types of scenes including: a fault occurring in a power distribution network region; the power distribution network fault causing main network stability loss and the power distribution network appearing microgrid island disturbance; according to the determined three types of scenes, corresponding emergency load control measures are taken in time scale in turn, and main network stability control devices are used to complete regulation and control; the application realizes fine emergency load control targets such as fast processing of power distribution network faults, emergency load removal and automatic load shedding based on priority, and improves the safe and stable operation ability of the power grid.

Description

Technical Field

[0001] This invention relates to the field of intelligent control technology for distribution networks, specifically a method, equipment, and medium for controlling distribution network faults and loads based on primary and secondary network coordination. Background Technology

[0002] Currently, load control in power systems mainly includes marketing load control systems and stability control load control systems, which differ in their control objectives, objects, and methods. Therefore, a targeted analysis is needed to determine their suitability for participation in emergency load control of the distribution network. Marketing load control systems are generally integrated into the marketing load control master station, primarily used to collect, monitor, and analyze electricity user consumption information, and to control and manage user electricity consumption behavior. The marketing load control master station can interact with user load control terminals in the low-voltage distribution network through communication channels such as private wireless networks, public wireless networks, or fiber optics, thereby meeting the needs of real-time user load monitoring; the interaction cycle is typically on the order of seconds.

[0003] Furthermore, with the large-scale integration of distributed power sources and flexible DC equipment, the power flow of the distribution network has shifted from the traditional unidirectional mode to a bidirectional mode, making the topology and operation increasingly complex. This significantly increases the requirements for power supply reliability and the real-time and accurate control of emergency loads. Currently, power system load control mainly relies on marketing load control systems and stable load control systems. The marketing load control system has an interaction cycle on the order of seconds, which cannot meet the millisecond-level real-time requirements of emergency load control in the distribution network. Although the stable load control system has millisecond-level control capabilities, it has significant shortcomings in distribution network applications and needs targeted optimization.

[0004] 1. Traditional load shedding systems have too large granularity in emergency load shedding and lack a precise classification mechanism based on load characteristics. They cannot distinguish between attributes such as load sensitivity and user level. In emergency situations, they are prone to accidentally shedding sensitive or necessary loads, causing unnecessary power loss and impact on users.

[0005] 2. The coordination between distribution network fault handling and load control is insufficient. Traditional solutions are difficult to adapt to scenarios with bidirectional power flow and variable topology. Fault location and isolation are slow, and there is a lack of effective coordination mechanism between the main grid and distribution network load control, making it impossible to quickly respond to the control needs of different fault or disturbance scenarios. Summary of the Invention

[0006] This invention provides a method, device, and medium for distribution network fault and load control based on master-distributor coordination. By controlling emergency loads in the distribution network through master-distributor coordination, it achieves refined emergency load control objectives such as rapid handling of distribution network faults, priority-based emergency load shedding, and automatic load reduction and disconnection, thereby improving the safe and stable operation capability of the power grid and solving the problems in the background art.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: A method for fault and load control in a distribution network based on primary and secondary distribution coordination includes an intelligent distribution terminal, which executes the following steps via computer equipment: S1, Monitoring, the intelligent distribution terminal monitors the distribution network data in real time, including the distribution network operating status, protection action signals, and operating parameters of distributed units and microgrids; S2, Judgment: Based on real-time monitoring of distribution network data, the intelligent distribution terminal comprehensively assesses the system status and determines three scenarios: a fault occurs within the distribution network area; a distribution network fault causes instability in the main grid; and a distribution network experiences microgrid islanding disturbances. S3, Execution: Based on the three scenarios determined, take corresponding emergency load control measures in sequence according to the time scale, and cooperate with the main grid stabilization device to complete the regulation; Preferably, the specific operation procedure of S1 is as follows: S11, Select each switch node of the distribution network along the assumed positive direction, divide the adjacent switches of each switch into upstream nodes, T nodes and downstream nodes, and complete the construction of the association relationship of all nodes of the distribution network; Furthermore, a general object-oriented real-time communication link for substation events is established between the intelligent distribution terminals of adjacent substations based on fiber optic channels. S12, the intelligent distribution terminal continuously monitors the operation status of the distribution network, and monitors and collects data in real time: including the operation status of the distribution network, protection action signals, and the operation parameters of distributed units and microgrids; S13, the intelligent power distribution terminal uses the user level, power outage loss, sensitivity and electricity consumption of each branch load as evaluation indicators, and uses fuzzy distribution method and fuzzy computing to obtain the scores of each indicator. Combined with the indicator weights calculated by the hierarchical analysis model, the hierarchical attribute score of each load branch is obtained through weighted calculation, and then the comprehensive score of the load branch is calculated. Based on the comprehensive score, the load priority hierarchical ranking is completed. S14, the intelligent distribution terminal counts the total load and available load at each level and sends it to the main distribution coordinated stability control substation. After the stability control substation summarizes the data reported by all terminals in the area, it sends it to the main distribution coordinated stability control center station in a unified manner, thus completing the hierarchical reporting of load data.

[0008] Preferably, the calculation process for the hierarchical attribute score of the load branch is as follows: The intelligent power distribution terminal uses the user level, power outage loss, sensitivity and power consumption of each branch load as evaluation indicators, calculates the level to which each load belongs through weighted calculation, and sends the total load of each level to the stability control substation. The weighted calculation method for each level is as follows:

[0009] in: For a certain level The hierarchical attribute score of each branch road; For the first The score of the i-th evaluation index of a branch is obtained using fuzzy distribution method and fuzzy computation; The weight of the i-th evaluation indicator is calculated by constructing a hierarchical analysis model; The stabilization substation summarizes and transmits the total load at each level to the terminal statistics, and evaluates the priority of each terminal. The calculation formula is as follows:

[0010] in: The comprehensive score of all branch loads of the Kth terminal in a certain level; m is the total number of branch loads connected to the terminal in this level; j is the serial number of the branch, representing the jth load branch connected to the distribution terminal in the current level. The summation calculation is a traversal variable with a traversal range of 1 to m, that is, all branches of the terminal in this level. The hierarchical attribute score of the j-th load branch to which the k-th intelligent power distribution terminal is connected within the current level.

[0011] Preferably, the specific operation process of S2 is as follows: S21, the intelligent distribution terminal collects the distribution network operation parameters, protection action signals and calculated load priorities, and synchronously receives the system status information fed back by the main grid stability control device to complete data verification and integration; S22, scenario-based judgment, based on integrated data analysis, identifies three scenarios: If the directional overcurrent protection action signal or the directional zero-sequence overcurrent protection action signal of the distribution network node is detected, it is determined to be a fault in the distribution network area; If the monitoring determines that a fault has occurred within the distribution network area, and the main grid stability control device reports a signal that the stability of the main grid has been compromised, it is determined that the main grid is unstable due to a distribution network fault, and load shedding must be performed. If, after load shedding, abnormalities are detected in the phase-to-phase voltage fundamental frequency and the maximum value of the three-phase line voltage fundamental at the microgrid connection point or centralized control point, and the frequency-voltage slip exceeds the standard threshold, it is determined that a microgrid islanding disturbance has occurred in the distribution network.

[0012] Preferably, the specific operation procedure of S3 is as follows: S31, based on the fault determination result within the distribution network area, execute a fast fault handling operation within 100ms: S32, based on the determination that the main network is unstable due to a distribution network fault, performs a load shedding operation within 200ms: S33, based on the determination result of microgrid islanding disturbance in the distribution network, initiate automatic load shedding and disconnection operation.

[0013] Preferably, the specific procedure for the rapid fault handling operation in S31 is as follows: The intelligent power distribution terminal uses the GOOSE link to multicast the protection actions and direction signals of the fault node, and locates the fault area based on the node topology association constructed by S11; it controls the switches in the fault area to open and isolate the fault, and after successful isolation, it forwards the isolation success signal to the adjacent nodes in sequence; when the tie switch in the open position receives the isolation success signal, it closes to complete the self-healing process of the non-faulty section.

[0014] Preferably, the specific procedure for the load shearing operation in S32 is as follows: S321, Scheme Formulation and Issuance: The stability control center station coordinates the total controllable load within the distribution network area, combines power deficit, and formulates a load shedding scheme based on the total load level reported by each stability control substation. The loads to be shedding are allocated sequentially according to the total load. If the total load of a certain level is insufficient, it is carried over to the next level, and the last level is allocated proportionally according to the total load. After the scheme is issued to each stability control substation, the substation sorts and summarizes the loads according to the load level first and then the terminal priority, calculates the total load shedding of each smart distribution terminal, and issues control commands. The priority of the last terminal is determined by the comprehensive score of the branches within the level. S322, Load shedding execution: After receiving the instruction from the stability control substation, the intelligent distribution terminal executes the shedding operation sequentially according to the load hierarchy sorting result calculated in S13.

[0015] Preferably, the specific process of the automatic load shedding and decoupling operation in S33 is as follows: Based on the judgment result of the microgrid islanding disturbance in the distribution network, the low-voltage and low-frequency automatic load shedding and disconnection function is activated: at the microgrid connection point or centralized control point, the load shedding and disconnection operation is performed in accordance with the principle of four basic cycles in sequence and two special cycles independently, in conjunction with the slip differential blocking element.

[0016] In another aspect, the present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0017] In another aspect, the present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described above.

[0018] As can be seen from the above technical solution compared with the prior art, the present invention has the following beneficial effects: 1. This invention, through the coordinated control of the main and distribution networks for emergency load control, effectively improves the efficiency of emergency load shedding in the stability control system while ensuring the speed and reliability of distribution network load management.

[0019] 2. This invention improves the safe and stable operation capability of the power grid by achieving the goals of rapid handling of distribution network faults, priority-based emergency load shedding, and automatic load reduction and disconnection through the main distribution network emergency load control. Attached Figure Description

[0020] Figure 1 This is a network diagram of the simulation system in an embodiment of the present invention; Figure 2 This is a graph showing the voltage and frequency response of node 7 in scenario 1 of this embodiment of the invention; Figure 3 This is a graph showing the voltage and frequency response of node 7 in scenario 2 of this embodiment of the invention. Figure 4 This is a schematic diagram of the power distribution network load shedding control framework according to an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0022] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but should not be used to limit the scope of the present invention.

[0023] Example 1: In this embodiment, in the actual operation scenario of medium- and high-voltage distribution networks with widespread access to distributed power sources and flexible DC equipment, the power flow of the distribution network exhibits bidirectional characteristics, and its topology and operation mode are complex and variable. Once a regional fault occurs in the distribution network, or a severe fault further disrupts the stability of the main grid, without efficient main-distribution coordinated emergency load control measures, it is easy to cause the fault range to expand, regional power supply to be interrupted, or even system disturbance problems such as microgrid islanding after load shedding. Therefore, a distribution network fault and load control method based on main-distribution coordination is cited in this application, which executes the following steps through computer equipment: S1, Monitoring, the intelligent distribution terminal monitors the distribution network data in real time, including the distribution network operating status, protection action signals, and operating parameters of distributed units and microgrids; S2, Judgment: Based on real-time monitoring of distribution network data, the intelligent distribution terminal comprehensively assesses the system status and determines three scenarios: a fault occurs within the distribution network area; a distribution network fault causes instability in the main grid; and a distribution network experiences microgrid islanding disturbances. S3, Execution: Based on the three scenarios determined, take corresponding emergency load control measures in sequence according to the time scale, and cooperate with the main grid stabilization device to complete the regulation; The specific operating procedure for S1 is as follows: S11, Select each switch node of the distribution network along the assumed positive direction, divide the adjacent switches of each switch into upstream nodes, T nodes and downstream nodes, and complete the construction of the association relationship of all nodes of the distribution network; Furthermore, a general object-oriented real-time communication link for substation events is established between the intelligent distribution terminals of adjacent substations based on fiber optic channels. S12, the intelligent distribution terminal continuously monitors the operation status of the distribution network, and monitors and collects data in real time: including the operation status of the distribution network, protection action signals, and the operation parameters of distributed units and microgrids; S13, the intelligent power distribution terminal uses the user level, power outage loss, sensitivity and electricity consumption of each branch load as evaluation indicators, and uses fuzzy distribution method and fuzzy computing to obtain the scores of each indicator. Combined with the indicator weights calculated by the hierarchical analysis model, the hierarchical attribute score of each load branch is obtained through weighted calculation, and then the comprehensive score of the load branch is calculated. Based on the comprehensive score, the load priority hierarchical ranking is completed. S14, the intelligent distribution terminal counts the total load and available load at each level and sends it to the main distribution coordinated stability control substation. After the stability control substation summarizes the data reported by all terminals in the area, it sends it to the main distribution coordinated stability control center station in a unified manner, thus completing the hierarchical reporting of load data.

[0024] The calculation process for the hierarchical attribute score of the load branch is as follows: The intelligent power distribution terminal uses the user level, power outage loss, sensitivity and power consumption of each branch load as evaluation indicators, calculates the level to which each load belongs through weighted calculation, and sends the total load of each level to the stability control substation. The weighted calculation method for each level is as follows:

[0025] in: For a certain level The hierarchical attribute score of each branch road; For the first The score of the i-th evaluation index of a branch is obtained using fuzzy distribution method and fuzzy computation; The weight of the i-th evaluation indicator is calculated by constructing a hierarchical analysis model; The stabilization substation summarizes and transmits the total load at each level to the terminal statistics, and evaluates the priority of each terminal. The calculation formula is as follows:

[0026] in: The comprehensive score of all branch loads of the Kth terminal in a certain level; m is the total number of branch loads connected to the terminal in this level; j is the serial number of the branch, representing the jth load branch connected to the distribution terminal in the current level. The summation calculation is a traversal variable with a traversal range of 1 to m, that is, all branches of the terminal in this level. The hierarchical attribute score of the j-th load branch to which the k-th intelligent power distribution terminal is connected within the current level.

[0027] The specific operating procedure for S2 is as follows: S21, the intelligent distribution terminal collects the distribution network operation parameters, protection action signals and calculated load priorities, and synchronously receives the system status information fed back by the main grid stability control device to complete data verification and integration; S22, scenario-based judgment, based on integrated data analysis, identifies three scenarios: If the directional overcurrent protection action signal or the directional zero-sequence overcurrent protection action signal of the distribution network node is detected, it is determined to be a fault in the distribution network area; If the monitoring determines that a fault has occurred within the distribution network area, and the main grid stability control device reports a signal that the stability of the main grid has been compromised, it is determined that the main grid is unstable due to a distribution network fault, and load shedding must be performed. If, after load shedding, abnormalities are detected in the phase-to-phase voltage fundamental frequency and the maximum value of the three-phase line voltage fundamental at the microgrid connection point or centralized control point, and the frequency-voltage slip exceeds the standard threshold, it is determined that a microgrid islanding disturbance has occurred in the distribution network.

[0028] The specific operating procedure for S3 is as follows: S31, based on the fault determination result within the distribution network area, execute a fast fault handling operation within 100ms: S32, based on the determination that the main network is unstable due to a distribution network fault, performs a load shedding operation within 200ms: S33, based on the determination result of microgrid islanding disturbance in the distribution network, initiate automatic load shedding and disconnection operation.

[0029] The specific procedure for rapid fault handling in S31 is as follows: The intelligent power distribution terminal uses the GOOSE link to multicast the protection actions and direction signals of the fault node, and locates the fault area based on the node topology association constructed by S11; it controls the switches in the fault area to open and isolate the fault, and after successful isolation, it forwards the isolation success signal to the adjacent nodes in sequence; when the tie switch in the open position receives the isolation success signal, it closes to complete the self-healing process of the non-faulty section.

[0030] The specific procedure for load shedding in S32 is as follows, and the load shedding control framework is as follows: Figure 4 As shown: S321, Scheme Formulation and Issuance: The stability control center station coordinates the total controllable load within the distribution network area, combines power deficit, and formulates a load shedding scheme based on the total load level reported by each stability control substation. The loads to be shedding are allocated sequentially according to the total load. If the total load of a certain level is insufficient, it is carried over to the next level, and the last level is allocated proportionally according to the total load. After the scheme is issued to each stability control substation, the substation sorts and summarizes the loads according to the load level first and then the terminal priority, calculates the total load shedding of each smart distribution terminal, and issues control commands. The priority of the last terminal is determined by the comprehensive score of the branches within the level. S322, Load shedding execution: After receiving the instruction from the stability control substation, the intelligent distribution terminal executes the shedding operation sequentially according to the load hierarchy sorting result calculated in S13.

[0031] The specific procedure for automatic load shedding and decoupling in S33 is as follows: Based on the judgment result of the microgrid islanding disturbance in the distribution network, the low-voltage and low-frequency automatic load shedding and disconnection function is activated: at the microgrid connection point or centralized control point, the load shedding and disconnection operation is performed in accordance with the principle of four basic cycles in sequence and two special cycles independently, in conjunction with the slip differential blocking element.

[0032] Example 2: To effectively verify the engineering effectiveness and practicality of the main-distribution coordinated distribution network emergency load control method proposed in Example 1 under such actual operating scenarios, this embodiment implements the main-distribution coordinated distribution network emergency load control method in the power system simulation software PSCAD. A 3-machine 9-node system is constructed to verify the effectiveness of the strategy. The system network structure is as follows: Figure 2 As shown.

[0033] Figure 1 In the middle: Three synchronous generators are connected to the system through nodes 1, 3 and 7, with output active power of 80, 170 and 90MW respectively; nodes 5, 8 and 9 are connected to loads of 120, 80 and 50MW respectively; two regional distribution networks are connected to the grid through nodes 2 and 6 via 220kV transformers, each carrying a load of 45MW.

[0034] A main distribution coordinated stability control substation is configured at substations A and B to divide the load in the distribution network into 8 levels and to count the total load of each level in real time. The load distribution of each level is shown in Table 1.

[0035] Table 1 Load distribution at each level

[0036] Simulation results: Scenario 1 employs a traditional low-frequency, low-voltage load shedding control scheme. When a fault causes generator G1 to disconnect, the system experiences a significant power deficit, resulting in a rapid drop in voltage and frequency. To prevent grid instability, the stability control device, according to a preset strategy, disconnects a total of 50MW of load from the 10kV feeders in substations A and B, restoring the system frequency and voltage to acceptable levels. The transient response curve of node 7 is shown below. Figure 2 As shown.

[0037] Although the power grid remains stable under severe power shortages, traditional load shedding control based on cycles has a long response time and large granularity of basic load shedding units, causing the system to operate in a low-voltage, low-frequency state for extended periods. Furthermore, directly disconnecting all outgoing lines from pre-set distribution terminals can cause power outages for a large number of critical users.

[0038] Scenario 2 employs a refined emergency control method based on main and distribution coordination. After generator G1 is disconnected, the stability control center calculates and issues load shedding commands based on the total shedding load and priority of each substation. The intelligent distribution terminal then sequentially executes the shedding of its subordinate branch lines according to the total load shedding command for the regional distribution network calculated by the stability control substation. The transient response curve of node 7 is shown below. Figure 3 As shown.

[0039] Compared to traditional load shedding schemes, the new method proposed in this paper offers shorter response times, significantly improved load shedding accuracy, and rapid recovery of system frequency and voltage. Furthermore, the basic unit for load shedding has been changed from random distribution across distribution network feeder lines to precise implementation based on branch load levels and terminal priorities, avoiding important and sensitive users and effectively reducing the impact and cost of stability control measures.

[0040] This application, by combining the current state of domestic distribution automation communication technology with the control characteristics and communication topology of the stability control system that require high speed and reliability, and making full use of the network resources of the existing distribution automation system and stability control system, proposes a set of main and distribution coordinated distribution network emergency load control system architecture and method, and conducts pilot application, which has the following main advantages.

[0041] The main-distribution coordinated distribution network emergency load control not only ensures the speed and reliability of distribution network load management, but also effectively improves the level of precision in emergency load shedding of the stability control system.

[0042] The coordinated emergency load control of the main distribution network not only achieves the goals of rapid handling of distribution network faults, priority-based emergency load shedding, and automatic load reduction and disconnection, but also improves the safe and stable operation capability of the power grid.

[0043] In another aspect, the present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0044] In another aspect, the present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described above.

[0045] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the above embodiments of a distribution network fault and load control method based on master-distributor coordination.

[0046] It is understood that the systems, devices, and storage media provided in the embodiments of the present invention correspond to the methods provided in the embodiments of the present invention, and the explanations, examples, and beneficial effects of the relevant content can be referred to the corresponding parts of the above methods.

[0047] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another.

[0048] For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media.

[0049] The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid state disks (SSDs)).

[0050] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0051] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0052] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0053] The embodiments of the present invention are given for the purposes of illustration and description. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for fault and load control in a distribution network based on primary and secondary distribution coordination, comprising an intelligent distribution terminal, characterized in that, Perform the following steps using a computer device: S1, Monitoring, the intelligent distribution terminal monitors the distribution network data in real time, including the distribution network operating status, protection action signals, and operating parameters of distributed units and microgrids; S2, Judgment: Based on real-time monitoring of distribution network data, the intelligent distribution terminal comprehensively assesses the system status and determines three scenarios: a fault occurs within the distribution network area; a distribution network fault causes instability in the main grid; and a distribution network experiences microgrid islanding disturbances. S3, Execution: Based on the three scenarios identified, take corresponding emergency load control measures in sequence according to the time scale, and cooperate with the main grid stabilization device to complete the regulation.

2. The method for distribution network fault and load control based on master-distributor coordination as described in claim 1, characterized in that: The specific operation procedure of S1 is as follows: S11, Select each switch node of the distribution network along the assumed positive direction, divide the adjacent switches of each switch into upstream nodes, T nodes and downstream nodes, and complete the construction of the association relationship of all nodes of the distribution network; Furthermore, a general object-oriented real-time communication link for substation events is established between the intelligent distribution terminals of adjacent substations based on fiber optic channels. S12, the intelligent distribution terminal continuously monitors the operation status of the distribution network, and monitors and collects data in real time: including the operation status of the distribution network, protection action signals, and the operation parameters of distributed units and microgrids; S13, the intelligent power distribution terminal uses the user level, power outage loss, sensitivity and electricity consumption of each branch load as evaluation indicators, and uses fuzzy distribution method and fuzzy computing to obtain the scores of each indicator. Combined with the indicator weights calculated by the hierarchical analysis model, the hierarchical attribute score of each load branch is obtained through weighted calculation, and then the comprehensive score of the load branch is calculated. Based on the comprehensive score, the load priority hierarchical ranking is completed. S14, the intelligent distribution terminal counts the total load and available load at each level and sends it to the main distribution coordinated stability control substation. After the stability control substation summarizes the data reported by all terminals in the area, it sends it to the main distribution coordinated stability control center station in a unified manner, thus completing the hierarchical reporting of load data.

3. The method for distribution network fault and load control based on primary and secondary distribution coordination as described in claim 2, characterized in that: The calculation process for the hierarchical attribute score of the load branch is as follows: The intelligent power distribution terminal uses the user level, power outage loss, sensitivity and power consumption of each branch load as evaluation indicators, calculates the level to which each load belongs through weighted calculation, and sends the total load of each level to the stability control substation. The weighted calculation method for each level is as follows: in: For a certain level The hierarchical attribute score of each branch road; For the first The score of the i-th evaluation index of a branch is obtained using fuzzy distribution method and fuzzy computation; The weight of the i-th evaluation indicator is calculated by constructing a hierarchical analysis model; The stabilization substation summarizes and transmits the total load at each level to the terminal statistics, and evaluates the priority of each terminal. The calculation formula is as follows: in: The comprehensive score of all branch loads of the Kth terminal in a certain level; m is the total number of branch loads connected to the terminal in this level; j is the serial number of the branch, representing the jth load branch connected to the distribution terminal in the current level. The summation calculation is a traversal variable with a traversal range of 1 to m, that is, all branches of the terminal in this level. The hierarchical attribute score of the j-th load branch to which the k-th intelligent power distribution terminal is connected within the current level.

4. The method for distribution network fault and load control based on primary and secondary coordination as described in claim 3, characterized in that: The specific operation procedure of S2 is as follows: S21, the intelligent distribution terminal collects the distribution network operation parameters, protection action signals and calculated load priorities, and synchronously receives the system status information fed back by the main grid stability control device to complete data verification and integration; S22, scenario-based judgment, based on integrated data analysis, identifies three scenarios: If the directional overcurrent protection action signal or the directional zero-sequence overcurrent protection action signal of the distribution network node is detected, it is determined to be a fault in the distribution network area; If the monitoring determines that a fault has occurred within the distribution network area, and the main grid stability control device reports a signal that the stability of the main grid has been compromised, it is determined that the main grid is unstable due to a distribution network fault, and load shedding must be performed. If, after load shedding, abnormalities are detected in the phase-to-phase voltage fundamental frequency and the maximum value of the three-phase line voltage fundamental at the microgrid connection point or centralized control point, and the frequency-voltage slip exceeds the standard threshold, it is determined that a microgrid islanding disturbance has occurred in the distribution network.

5. The method for distribution network fault and load control based on master-distributor coordination as described in claim 4, characterized in that: The specific operation procedure of S3 is as follows: S31, based on the fault determination result within the distribution network area, execute a fast fault handling operation within 100ms: S32, based on the determination that the main network is unstable due to a distribution network fault, performs a load shedding operation within 200ms: S33, based on the determination result of microgrid islanding disturbance in the distribution network, initiate automatic load shedding and disconnection operation.

6. The method for distribution network fault and load control based on master-distributor coordination as described in claim 5, characterized in that: The specific procedure for the rapid fault handling operation in S31 is as follows: The intelligent power distribution terminal uses the GOOSE link to multicast the protection actions and direction signals of the fault node, and locates the fault area based on the node topology association constructed by S11; it controls the switches in the fault area to open and isolate the fault, and after successful isolation, it forwards the isolation success signal to the adjacent nodes in sequence; when the tie switch in the open position receives the isolation success signal, it closes to complete the self-healing process of the non-faulty section.

7. The method for distribution network fault and load control based on primary and secondary distribution coordination as described in claim 5, characterized in that: The specific procedure for the load shearing operation in S32 is as follows: S321, Scheme Formulation and Issuance: The stability control center station coordinates the total controllable load within the distribution network area, combines power deficit, and formulates a load shedding scheme based on the total load level reported by each stability control substation. The loads to be shedding are allocated sequentially according to the total load. If the total load of a certain level is insufficient, it is carried over to the next level, and the last level is allocated proportionally according to the total load. After the scheme is issued to each stability control substation, the substation sorts and summarizes the loads according to the load level first and then the terminal priority, calculates the total load shedding of each smart distribution terminal, and issues control commands. The priority of the last terminal is determined by the comprehensive score of the branches within the level. S322, Load shedding execution: After receiving the instruction from the stability control substation, the intelligent distribution terminal executes the shedding operation sequentially according to the load hierarchy sorting result calculated in S13.

8. The method for distribution network fault and load control based on primary and secondary coordination as described in claim 5, characterized in that: The specific process of the automatic load shedding and decoupling operation in S33 is as follows: Based on the judgment result of the microgrid islanding disturbance in the distribution network, the low-voltage and low-frequency automatic load shedding and disconnection function is activated: at the microgrid connection point or centralized control point, the load shedding and disconnection operation is performed in accordance with the principle of four basic cycles in sequence and two special cycles independently, in conjunction with the slip differential blocking element.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it causes the processor to perform the steps of the method as described in any one of claims 1 to 8.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the computer program is executed by the processor, it causes the processor to perform the steps of the method as described in any one of claims 1 to 8.

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