Scheduling method and system based on linear alternating current power flow

Abstract

The invention discloses a scheduling method and system based on linear alternating current power flow, and belongs to the technical field of electric power, and the method comprises the steps: setting a probability threshold value based on a vulnerability curve of real-time disaster data, and carrying out the screening to form an anticipated initial fault set; the power grid topology is modified according to fault and overload information, and islands are identified and separated according to breadth-first search; calculating an island expected lowest frequency and executing a recovery operation; calculating power flow based on a linear alternating current power flow model, and simulating relay protection and safety self device operation; identifying an overload branch according to the overload severity index and circularly processing the overload branch; and executing the optimal scheduling strategy to eliminate overload. According to the method, the problems of low cascading failure simulation accuracy, unstable power flow solution and the like under the extreme disaster are solved, the fault simulation authenticity and the dispatching reliability are improved, cascading failure spreading can be effectively blocked, the load loss is reduced, and support is provided for stable operation of a power system in the disaster.

Description

Technical Field

[0001] This invention belongs to the field of power technology, specifically relating to a scheduling method and system based on linear AC power flow. Background Technology

[0002] In recent years, extreme disasters have occurred frequently. The impact of disasters such as typhoons, earthquakes, and heavy rainfall on power systems has become increasingly severe. Extreme scenarios, which differ from traditional operating conditions, have become a major threat to the stable operation of power systems. As a key link connecting the initial fault and system collapse in the evolution of disasters, cascading failures have complex evolution mechanisms and are affected by the coupling of multiple factors, making it difficult for existing technologies to accurately control them.

[0003] The core problems currently existing include: First, the initial fault set screening lacks scientific basis and does not fully combine multi-dimensional parameters such as component health status and disaster intensity, resulting in a large deviation in fault prediction; Second, island identification methods are inefficient and cannot quickly adapt to the dynamic changes in the power grid topology under disasters, affecting the timeliness of subsequent control measures; Third, the power flow calculation model is not stable enough and is prone to divergence in complex fault scenarios. Furthermore, it is not closely integrated with the control strategies of relay protection and safety automatic devices, and cannot accurately simulate the impact of device actions on fault evolution. Fourth, the identification of overloaded branches lacks quantitative indicators, and the decision to disconnect them is highly subjective, which can easily lead to the spread of faults. Fifth, the post-disaster dispatch strategy did not take into account both load loss and power generation costs, resulting in poor optimization.

[0004] These problems make it difficult for existing cascading failure models to accurately simulate the failure evolution process under disasters, and they cannot provide reliable support for emergency control during disasters. They can easily cause the power system to gradually evolve from an initial local failure to a complete collapse, resulting in large-scale power outages and significant economic losses. There is an urgent need for a comprehensive, adaptable, accurate and efficient dispatching method and system that integrates multiple factors. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a scheduling method and system based on linear AC power flow. This method and system are used to solve the technical problems of low accuracy in cascading fault simulation, unstable power flow solution, weak integration with relay protection and automatic safety device control strategies, unscientific initial fault screening, low efficiency in islanding identification and overload handling, and poor optimization effect of post-disaster scheduling strategies under extreme disasters. This invention achieves accurate simulation and effective control of cascading faults, provides reliable support for emergency control during disasters, and ensures stable operation of the power system.

[0006] The present invention adopts the following technical solution: A scheduling method based on linear AC power flow includes the following steps: S1. Based on the vulnerability curve of real-time disaster data, set a probability threshold and filter to form a set of anticipated initial faults; S2. Modify the power grid topology based on the initial fault information and branch overload information, and identify and separate islands based on breadth-first search; S3. For each isolated island separated in step S2, calculate the expected minimum frequency for each island and perform the corresponding frequency recovery operation. S4. Based on the grid state after frequency recovery in step S3, calculate the power flow according to the linear AC power flow model, and then simulate the operation of relay protection and automatic safety devices by combining node voltage and generator output. Repeat the power flow calculation until there are no relay protection and automatic safety devices that need to perform actions. S5. Based on the short-time thermal stability capacity of the branch, identify the overloaded branches of each island after processing in step S4 according to the overload severity index. Select the most severe overloaded branch as the overload disconnection branch and return to step S2 to re-execute the island identification until there are no overloaded branches. S6. Based on the branch capacity under normal operating conditions, implement the optimal dispatching strategy to eliminate grid overload and simulate the overload elimination operation of the dispatcher after the disaster.

[0007] Preferably, in step S1, the vulnerability curve is calculated based on the current score of the component health index, the disaster intensity, the critical no-failure disaster intensity, the disaster intensity that guarantees failure, and the mean and standard deviation of the log-normal distribution to calculate the component failure probability.

[0008] Preferably, in step S2, the process of identifying and separating isolated nodes based on breadth-first search includes: randomly selecting nodes based on the branch association matrix and then traversing their connected nodes according to the breadth-first principle. After completion, randomly selecting unsearched nodes until all nodes have been traversed, thereby achieving isolated node identification and separation.

[0009] Preferably, in step S3, the formula for calculating the expected lowest frequency is:

[0010] in, For unbalanced active power, and These are collections of generators and busbars. and The first The generator and the first The frequency coefficient of the load.

[0011] Preferably, in step S4, the system power flow is represented as follows:

[0012] in, , These are the phase angles corresponding to the generator node and the load node, respectively. This represents the voltage amplitude corresponding to the load node. , Inject compensation for active power and compensation for reactive power into the nodes. , , , The node admittance matrix is ​​divided into blocks according to the node type.

[0013] Preferably, the operation of the relay protection and safety automatic device includes low-voltage load shearing operation.

[0014] Preferably, in step S5, the overload severity index for:

[0015] in, For the current power, Power before the fault. This is the maximum power rating.

[0016] Preferably, the short-time thermal stability capacity of the branch is determined based on the line material and environmental parameters.

[0017] Preferably, in step S6, the optimal scheduling strategy table is:

[0018] in, For bus load, To provide power to the generator, For the initial load, For the maximum output, As a penalty factor for load loss, The cost function of the generator output. This is the correlation matrix between generators and nodes. The system susceptance matrix, The voltage phase angle at the reference node, This represents the actual active power transmitted by the branch.

[0019] Secondly, embodiments of the present invention provide a scheduling system based on linear AC power flow, comprising: The generation module is used to set probability thresholds based on the vulnerability curves of real-time disaster data and filter to form a set of anticipated initial faults; The islanding module is used to modify the power grid topology based on initial fault information and branch overload information, and to identify and separate islands using breadth-first search. The frequency module is used to calculate the expected minimum frequency for each island separated by the islanding module and perform the corresponding frequency recovery operation. The power flow module is used to complete the power grid state after frequency recovery based on the frequency module. It calculates the power flow according to the linear AC power flow model, and then simulates the operation of relay protection and automatic safety devices by combining node voltage and generator output. The power flow calculation is repeatedly executed until there is no relay protection and automatic safety device that needs to perform an action. The overload module is used to identify overloaded branches in each island after the power flow module is processed, based on the short-time thermal stability capacity of the branch and the overload severity index. It selects the most severe overloaded branch, marks it as the overload disconnection branch, and returns to the island module to re-execute the island identification until there are no overloaded branches. The scheduling module is used to execute the optimal scheduling strategy to eliminate grid overload based on the branch capacity under normal operating conditions, simulating the overload elimination operation of the dispatcher after a disaster.

[0020] Thirdly, a computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the above-described scheduling method based on linear AC power flow.

[0021] Fourthly, embodiments of the present invention provide a computer-readable storage medium including a computer program, which, when executed by a processor, implements the steps of the above-described scheduling method based on linear AC power flow.

[0022] Fifthly, a chip includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the above-described scheduling method based on linear AC power flow.

[0023] In a sixth aspect, embodiments of the present invention provide an electronic device, including a computer program, which, when executed by the electronic device, implements the steps of the above-described scheduling method based on linear AC power flow.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects: A scheduling method based on linear AC power flow integrates a linear AC power flow model, breadth-first search for islanding detection, frequency recovery, protection device simulation, overload identification, and optimal scheduling to form a closed-loop processing flow. This overcomes the limitations of existing methods, such as fragmented processes and poor coordination between stages. By cyclically executing islanding detection and overload handling, it effectively prevents the spread of cascading faults. The combination of the linear AC power flow model with the operation simulation of relay protection and safety automation devices improves the stability of power flow solutions and the realism of fault simulation, avoiding the poor adaptability of single models. The entire process requires no complex and redundant operations, balancing processing efficiency and control accuracy. It provides systematic technical support for emergency control during disasters, effectively preventing the system from evolving from an initial fault to a complete collapse, and is adaptable to dynamic power grid scenarios under extreme disasters.

[0025] Furthermore, by using the vulnerability curves of component health index and disaster parameters, the initial fault set can be accurately screened, improving the authenticity and representativeness of the initial fault set; and providing reliable input for subsequent cascading fault simulation.

[0026] Furthermore, a breadth-first search is employed to achieve fast and accurate island identification. The algorithm is simple and efficient, suitable for large-scale power grid topology changes, and ensures the integrity of island separation.

[0027] Furthermore, by calculating the expected minimum frequency, a quantitative assessment of the frequency stability of each island can be achieved. Advantages: Provides a scientific basis for frequency recovery operations; prevents system crashes caused by frequency instability.

[0028] Furthermore, a linear AC power flow model is adopted to accurately simulate the power flow distribution of the system, balancing computational efficiency and accuracy; it can accurately reflect the impact of node voltage and reactive power.

[0029] Furthermore, the operation of protection devices such as low-voltage load shearing is incorporated into the simulation process to improve the consistency between the model and the actual system operation, thereby enhancing the realism of fault simulation.

[0030] Furthermore, an overload severity index is introduced to quantify the degree of branch overload, providing a scientific basis for decision-making regarding the disconnection of overloaded branches and avoiding system risks caused by blind operation.

[0031] Furthermore, the short-term thermal stability capacity is determined based on line materials and environmental parameters to improve the accuracy of overload assessment and ensure the rationality of branch circuit disconnection decisions.

[0032] Furthermore, an optimal scheduling model that considers load loss penalties and power generation costs is constructed to achieve a balance between economy and safety, providing an optimized scheduling scheme for post-disaster recovery.

[0033] It is understood that the beneficial effects of the second to sixth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0034] In summary, this invention, based on multi-parameter fault prediction, achieves accurate simulation and effective control of cascading faults through efficient islanding identification, stable power flow calculation, quantified overload processing, and multi-objective optimized scheduling, taking into account reliability, efficiency, and economy, and providing comprehensive technical support for the stability of power systems during disasters.

[0035] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0036] Figure 1 This is a flowchart of the present invention; Figure 2 This is a schematic diagram of the topology and earthquake hazard distribution of the test system; Figure 3 A schematic diagram of a computer device provided in an embodiment of the present invention; Figure 4 This is a block diagram of a chip provided according to an embodiment of the present invention.

[0037] Among them, 60. Computer equipment; 61. Processor; 62. Memory; 63. Computer program; 600. Electronic device; 610. Processing unit; 620. Storage unit; 6201. Random access memory unit; 6202. Cache memory unit; 6203. Read-only memory unit; 6204. Program / utility; 6205. Program module; 630. Bus; 640. Display unit; 650. Input / output interface; 660. Network adapter; 700. External device. Detailed Implementation

[0038] 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 only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0040] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0041] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0042] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0043] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0044] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0045] This invention provides a scheduling method based on linear AC power flow. An initial fault set is generated based on the vulnerability curve under disaster conditions. Breadth-first search is used to identify and separate islands. Then, the expected frequency is calculated to select relay protection and safety automatic control measures. Next, a linear AC power flow model is used to calculate the power flow, and overload severity indicators are combined to select disconnected lines. The process then returns to island identification, continuously iterating until no overload occurs. This invention has better power flow solution stability, can be better integrated with relay protection and safety automatic control strategies, and more accurately simulates real-world cascading faults.

[0046] Please see Figure 1 The present invention provides a scheduling method based on linear AC power flow, comprising the following steps: S1. Based on the vulnerability curve of real-time disaster data, set probability thresholds, filter to form a set of anticipated initial faults, and then input them into the model in sequence; Relationship between fragility curves, specific component parameters, and disaster data:

[0047] in, As for the intensity of the disaster, The critical level of disaster intensity where no failure occurs. To ensure the severity of the disaster in the event of a malfunction, and These are the mean and standard deviation of a log-normal distribution, respectively. This is the current score for the component health index.

[0048] S2. Modify the power grid topology based on the initial fault information and branch overload information, and identify and separate islands based on breadth-first search; Based on the branch association matrix, after randomly selecting a node, its connected nodes are traversed in a breadth-first manner. After completion, unsearched nodes are randomly selected until all nodes have been traversed, and finally the island identification and separation are completed.

[0049] S3. Calculate the expected minimum frequency for each isolated island and perform recovery operations at different frequencies. The system's expected minimum frequency is expressed as:

[0050] in, For unbalanced active power, and These are collections of generators and busbars. and The first The generator and the first The frequency coefficient of the load, and These represent the active power generated by the generator and the active power consumed by the load, respectively. The active power loss of a system or isolated network.

[0051] S4. Calculate the power flow based on the linear AC power flow model, simulate the operation of relay protection and safety automatic devices such as low-voltage load shedding according to node voltage and generator output, and repeatedly execute the power flow calculation until no operation is executed. The system power flow is represented as:

[0052] in, , These are the phase angles corresponding to the generator node and the load node, respectively. This represents the voltage amplitude corresponding to the load node. , Inject compensation for active power and compensation for reactive power into the nodes. , , , The node admittance matrix is ​​divided into blocks according to the node type.

[0053] S5. Based on the short-time thermal stability capacity of the branch, identify the overloaded branches in each island according to the overload severity index, select the most severe branch as the overload disconnection branch and go to step S2; if there are no overloaded branches, go to step S6. The overload severity index is expressed as:

[0054] in, For the current power, Power before the fault. This is the maximum power rating.

[0055] S6. Based on the branch capacity under normal operating conditions, implement the optimal scheduling strategy to eliminate overload and simulate the overload elimination operation of the dispatcher after the disaster.

[0056] The optimal strategy is expressed as:

[0057] Among them, the variable is the bus load. With generator output The bus load is limited to With initial load Between, meaning only load reduction is allowed, the generator output is within With the extreme value of output between, As a penalty factor for load loss, The cost function for generator output.

[0058] In another embodiment of the present invention, a scheduling system based on linear AC power flow is provided. This system can be used to implement the above-mentioned scheduling method based on linear AC power flow. Specifically, the scheduling system based on linear AC power flow includes a generation module, an islanding module, a frequency module, a power flow module, an overload module, and a scheduling module.

[0059] The generation module is used to set probability thresholds based on the vulnerability curves of real-time disaster data and to filter and form a set of anticipated initial faults. The islanding module is used to modify the power grid topology based on initial fault information and branch overload information, and to identify and separate islands using breadth-first search. The frequency module is used to calculate the expected minimum frequency for each island separated by the islanding module and perform the corresponding frequency recovery operation. The power flow module is used to complete the power grid state after frequency recovery based on the frequency module. It calculates the power flow according to the linear AC power flow model, and then simulates the operation of relay protection and automatic safety devices by combining node voltage and generator output. The power flow calculation is repeatedly executed until there is no relay protection and automatic safety device that needs to perform an action. The overload module is used to identify overloaded branches in each island after the power flow module is processed, based on the short-time thermal stability capacity of the branch and the overload severity index. It selects the most severe overloaded branch, marks it as the overload disconnection branch, and returns to the island module to re-execute the island identification until there are no overloaded branches. The scheduling module is used to execute the optimal scheduling strategy to eliminate grid overload based on the branch capacity under normal operating conditions, simulating the overload elimination operation of the dispatcher after a disaster.

[0060] This invention provides a terminal device comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to implement a corresponding method flow or corresponding function. The processor described in this embodiment can be used for the operation of a scheduling method based on linear AC power flow, including: Based on the vulnerability curves of real-time disaster data, probability thresholds are set to filter and form a set of anticipated initial faults. The power grid topology is modified according to the initial fault information and branch overload information, and islands are identified and separated using breadth-first search. For each separated island, the expected minimum frequency is calculated, and the corresponding frequency recovery operation is performed. Based on the power grid state after frequency recovery, the power flow is calculated according to the linear AC power flow model, and the operation of relay protection and automatic safety devices is simulated in combination with node voltage and generator output. The power flow calculation is repeatedly performed until no relay protection or automatic safety device needs to perform an action. Based on the short-term thermal stability capacity of the branches, overload branches are identified for each processed island according to the overload severity index. The most severely overloaded branch is marked as the overload disconnection branch, and the island identification is re-executed until there are no overloaded branches. Based on the branch capacity under normal operating conditions, the optimal scheduling strategy for eliminating power grid overload is executed, simulating the overload elimination operation of the dispatcher after the disaster.

[0061] Please see Figure 3The terminal device is a computer device. In this embodiment, the computer device 60 includes a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When executed by the processor 61, the computer program 63 implements the scheduling method based on linear AC power flow in this embodiment. To avoid repetition, these details are not elaborated here. Alternatively, when executed by the processor 61, the computer program 63 implements the functions of each model / unit in the scheduling system based on linear AC power flow in this embodiment. To avoid repetition, these details are not elaborated here.

[0062] Computer device 60 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. Computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will understand that... Figure 3 This is merely an example of computer device 60 and does not constitute a limitation on computer device 60. It may include more or fewer components than shown, or combine certain components, or different components. For example, computer device may also include input / output devices, network access devices, buses, etc.

[0063] The processor 61 may be a Central Processing Unit (CPU), or other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0064] The memory 62 can be an internal storage unit of the computer device 60, such as a hard disk or RAM of the computer device 60. The memory 62 can also be an external storage device of the computer device 60, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., provided on the computer device 60.

[0065] Furthermore, the memory 62 may include both internal storage units of the computer device 60 and external storage devices. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 can also be used to temporarily store data that has been output or will be output.

[0066] Please see Figure 4 The terminal device is an electronic device 600, which is manifested in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including storage unit 620 and processing unit 610), a display unit 640, etc.

[0067] The storage unit stores program code, which can be executed by the processing unit 610 to perform the steps described in the method section of this specification according to various exemplary embodiments of the present invention. For example, the processing unit 610 can perform actions such as... Figure 1 The steps are shown in the figure.

[0068] Storage unit 620 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 6201 and / or cache memory 6202, and may further include a read-only memory (ROM) 6203.

[0069] Storage unit 620 may also include a program / utility 6204 having a set (at least one) program module 6205, such program module 6205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0070] Bus 630 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the multiple bus structures.

[0071] Electronic device 600 can also communicate with one or more external devices 700 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 600, and / or with any device that enables electronic device 600 to communicate with one or more other computing devices (e.g., router, modem). This communication can be performed via input / output interface 650. Furthermore, electronic device 600 can also communicate with one or more networks (e.g., local area network, wide area network, and / or public network, such as the Internet) via network adapter 660. Network adapter 660 can communicate with other modules of electronic device 600 via bus 630. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms.

[0072] Example 4 This invention also provides a storage medium, specifically a computer-readable storage medium, which is a memory device in a terminal device for storing programs and data. It is understood that the computer-readable storage medium here can include both built-in storage media in the terminal device and extended storage media supported by the terminal device; it can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor, which can be one or more computer programs (including program code). More specific examples of the computer-readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical fiber, portable compact disk read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0073] Computer-readable storage media also include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable storage medium can also be any readable medium other than a readable storage medium that can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium can be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, radio frequency, etc., or any suitable combination thereof.

[0074] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0075] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the scheduling method based on linear AC power flow in the above embodiments; one or more instructions in the computer-readable storage medium are loaded and executed by the processor to perform the following steps: Based on the vulnerability curves of real-time disaster data, probability thresholds are set to filter and form a set of anticipated initial faults. The power grid topology is modified according to the initial fault information and branch overload information, and islands are identified and separated using breadth-first search. For each separated island, the expected minimum frequency is calculated, and the corresponding frequency recovery operation is performed. Based on the power grid state after frequency recovery, the power flow is calculated according to the linear AC power flow model, and the operation of relay protection and automatic safety devices is simulated in combination with node voltage and generator output. The power flow calculation is repeatedly performed until no relay protection or automatic safety device needs to perform an action. Based on the short-term thermal stability capacity of the branches, overload branches are identified for each processed island according to the overload severity index. The most severely overloaded branch is marked as the overload disconnection branch, and the island identification is re-executed until there are no overloaded branches. Based on the branch capacity under normal operating conditions, the optimal scheduling strategy for eliminating power grid overload is executed, simulating the overload elimination operation of the dispatcher after the disaster.

[0076] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0077] 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 only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0078] Please see Figure 2 , Figure 2 This diagram illustrates the topology and seismic hazard distribution of the test system. The system comprises 32 nodes, multiple transmission lines, and power components, clearly showing the topological connections of the power grid and the spatial distribution characteristics of seismic hazards. Significant differences in hazard intensity are observed across different regions, with high-hazard-intensity areas concentrated in the central and southern parts of the system. Transmission lines in these areas (such as lines 6-7 and 15-16) face a higher risk of failure due to the hazard, providing a realistic scenario basis for selecting the initial fault set. The scheduling method of this invention is based on the actual topology and hazard distribution of this test system, with targeted design of technical measures for each stage, ensuring a high degree of fit between the technical solution and the actual application scenario.

[0079] Table 1. Examples of results from running the cascading failure model on the test system.

[0080] Please refer to Table 1 for an example of the results of the cascading failure model running on the test system. The data clearly demonstrates the significant advantages of this invention: when the initial fault line is 14-15 or 4-14, 12-13, the full-process scheduling of this invention prevents subsequent faults, and the total load loss rate is 0, proving that it can effectively block the evolution of mild to moderate initial faults; when the initial fault is 14-15, 16-19, only one subsequent fault line appears, and the total load loss rate is controlled at 0.1087, demonstrating effective control over moderate faults; even when the initial fault is more severe (6-7, 6-31, 15-16 fail simultaneously), although four subsequent fault lines appear, the total load loss rate is still controlled at 0.4254, which significantly reduces losses compared to existing technologies. These test results fully verify the core advantages of this invention in accurately simulating cascading faults, curbing fault propagation, and reducing load loss rates, proving that it can provide reliable technical support for emergency control during disasters.

[0081] In summary, this invention provides a scheduling method and system based on linear AC power flow. It generates an initial fault set based on vulnerability curves under disaster conditions, uses breadth-first search to identify and separate islanded faults, then calculates the expected frequency to select relay protection and safety automatic control measures, and further uses a linear AC power flow model to calculate the power flow. Combining this with overload severity indicators, it selects lines to be disconnected, then returns to islanded fault identification, continuously looping until no overload occurs. Compared with existing cascading fault models, this method offers better power flow solution stability, better integration with relay protection and safety automatic control strategies, and more accurately simulates real-world cascading faults.

[0082] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0083] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0084] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0085] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0086] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0087] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0088] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random-access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0089] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus, and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0090] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0091] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0092] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A scheduling method based on linear AC power flow, characterized in that, Includes the following steps: S1. Based on the vulnerability curve of real-time disaster data, set a probability threshold and filter to form a set of anticipated initial faults; S2. Modify the power grid topology based on the initial fault information and branch overload information, and identify and separate islands based on breadth-first search; S3. For each isolated island separated in step S2, calculate the expected minimum frequency for each island and perform the corresponding frequency recovery operation. S4. Based on the grid state after frequency recovery in step S3, calculate the power flow according to the linear AC power flow model, and then simulate the operation of relay protection and automatic safety devices by combining node voltage and generator output. Repeat the power flow calculation until there are no relay protection and automatic safety devices that need to perform actions. S5. Based on the short-time thermal stability capacity of the branch, identify the overloaded branches of each island after processing in step S4 according to the overload severity index. Select the most severe overloaded branch as the overload disconnection branch and return to step S2 to re-execute the island identification until there are no overloaded branches. S6. Based on the branch capacity under normal operating conditions, implement the optimal dispatching strategy to eliminate grid overload and simulate the overload elimination operation of the dispatcher after the disaster.

2. The scheduling method based on linear AC power flow according to claim 1, characterized in that, In step S1, the vulnerability curve calculates the component failure probability based on the current score of the component health index, disaster intensity, critical failure-free disaster intensity, guaranteed failure-free disaster intensity, and the mean and standard deviation of the log-normal distribution.

3. The scheduling method based on linear AC power flow according to claim 1, characterized in that, In step S2, the process of identifying and separating isolated nodes based on breadth-first search includes: randomly selecting nodes based on the branch association matrix and then traversing their connected nodes in a breadth-first manner. After completion, randomly selecting unsearched nodes until all nodes have been traversed, thereby achieving the identification and separation of isolated nodes.

4. The scheduling method based on linear AC power flow according to claim 1, characterized in that, In step S3, the formula for calculating the expected minimum frequency is: in, For unbalanced active power, and These are collections of generators and busbars, respectively. and The first The generator and the first The frequency coefficient of the load.

5. The scheduling method based on linear AC power flow according to claim 1, characterized in that, In step S4, the system power flow is represented as follows: in, , These are the phase angles corresponding to the generator node and the load node, respectively. This represents the voltage amplitude corresponding to the load node. , Inject compensation for active power and compensation for reactive power into the nodes. , , , The node admittance matrix is ​​divided into blocks according to the node type.

6. The scheduling method based on linear AC power flow according to claim 5, characterized in that, The operation of the relay protection and safety automatic device includes low-voltage load shedding operation.

7. The scheduling method based on linear AC power flow according to claim 1, characterized in that, In step S5, the overload severity index for: in, For the current power, Power before the fault. This is the maximum power rating.

8. The scheduling method based on linear AC power flow according to claim 7, characterized in that, The short-time thermal stability capacity of the branch is determined based on the line materials and environmental parameters.

9. The scheduling method based on linear AC power flow according to claim 1, characterized in that, In step S6, the optimal scheduling strategy table is as follows: in, For bus load, To provide power to the generator, For the initial load, For the maximum output, As a penalty factor for load loss, The cost function of the generator output. This is the correlation matrix between generators and nodes. The system susceptance matrix, The voltage phase angle at the reference node, This represents the actual active power transmitted by the branch.

10. A scheduling system based on linear AC power flow, characterized in that, include: The generation module is used to set probability thresholds based on the vulnerability curves of real-time disaster data and filter to form a set of anticipated initial faults; The islanding module is used to modify the power grid topology based on initial fault information and branch overload information, and to identify and separate islands using breadth-first search. The frequency module is used to calculate the expected minimum frequency for each island separated by the islanding module and perform the corresponding frequency recovery operation. The power flow module is used to complete the power grid state after frequency recovery based on the frequency module. It calculates the power flow according to the linear AC power flow model, and then simulates the operation of relay protection and automatic safety devices by combining node voltage and generator output. The power flow calculation is repeatedly executed until there is no relay protection and automatic safety device that needs to perform an action. The overload module is used to identify overloaded branches in each island after the power flow module is processed, based on the short-time thermal stability capacity of the branch and the overload severity index. It selects the most severe overloaded branch, marks it as the overload disconnection branch, and returns to the island module to re-execute the island identification until there are no overloaded branches. The scheduling module is used to execute the optimal scheduling strategy to eliminate grid overload based on the branch capacity under normal operating conditions, simulating the overload elimination operation of the dispatcher after a disaster.

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