Post-disaster island division method and system for power system

Abstract

The invention discloses a post-disaster island division method and system for a power system, and the method comprises the steps: carrying out the simulation analysis of obtained data, and determining a circuit topological structure; carrying out analogue simulation on the circuit topological structure; performing iteration processing on the simulation output result to obtain a reference splitting point, and determining a reference splitting boundary according to the reference splitting point; performing stability domain boundary calculation on the variable at the reference splitting point according to the stability domain estimation to obtain a reference splitting boundary; outputting a final splitting priority according to the voltage stability margin of the reference splitting boundary; determining active splitting boundaries under different disaster conditions based on a selected standard condition and the splitting priority, and determining an active splitting area of the target power distribution network based on the active splitting boundaries; and in the division process of the post-disaster island power grid, executing a splitting strategy corresponding to the active splitting area matched with the disaster condition. According to the post-disaster island division method of the power system, the island division process of the power system can be optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of emergency repair and dispatching of electric power systems, and in particular to a method and system for dividing isolated islands after a disaster in an electric power system. Background Art

[0002] With the change of environmental climate, various extreme weather disasters occur frequently. The characteristics of the distribution network, such as wide distribution, many lines and huge number of users, determine that it is extremely vulnerable to the threat of natural disasters, thus causing large-scale power outages. Therefore, it is necessary to achieve reliable and continuous power supply to key loads through island division after natural disasters occur.

[0003] In the prior art, conventional island division divides all areas into islands. However, too many islands will make it extremely complicated for the power grid to coordinate the operating status and load changes of each island. Therefore, how to optimize the island division process of the power system has become a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0004] The present invention provides a method and system for dividing isolated islands after a disaster in an electric power system, so as to solve the technical problem of how to optimize the isolated island division of the electric power system and achieve the effect of power supply to key loads. The method for dividing isolated islands after a disaster in an electric power system comprises: Conduct simulation analysis on the acquired disaster data of the disaster area and the initial power data of the target distribution network to determine the circuit topology structure that currently meets the normal operation requirements; Building a power grid simulation operation model based on the circuit topology structure, and obtaining an output result of the power grid simulation operation model; Iteratively processing the output result using the Newton-Raphson method to obtain a reference decoupling point, and determining a reference decoupling boundary according to the reference decoupling point; wherein the reference decoupling boundary is configured to perform a stability domain boundary calculation on a variable at the reference decoupling point according to a stability domain estimation to obtain the reference decoupling boundary; Outputting a final decoupling priority according to the voltage stability margin of the reference decoupling boundary; Determine active disconnection boundaries under different disaster conditions based on the selected standard conditions and the disconnection priority, and determine active disconnection areas of the target distribution network based on the active disconnection boundaries; During the division of the target distribution network into islanded power grids after a disaster, a disconnection strategy corresponding to the active disconnection area matching the current disaster conditions is executed.

[0005] As one of the preferred solutions, before simulating and analyzing the acquired disaster data of the disaster area and the initial power data of the target distribution network, the post-disaster island division method of the power system further includes: The disaster-affected data of the disaster area and the initial power data of the target power distribution network are preprocessed, and the preprocessing steps include data cleaning, standardization of the disaster-affected data and normalization of the initial power data.

[0006] As one of the preferred solutions, the process of constructing the circuit topology structure includes: Perform spatial overlay analysis on the geographical scope of the disaster area and the geographical location of the target distribution network to determine the power facilities in the target distribution network affected by the disaster; The power flow parameters of the power facility are calculated based on a fast decoupling power flow algorithm, and a circuit topology structure corresponding to the current normal operation requirements is constructed based on the power facility and the power flow parameters.

[0007] As one of the preferred solutions, the output results of the power grid simulation operation model include one or more of the following: node voltage amplitude, phase angle, current and line power flow direction and size.

[0008] As one of the preferred solutions, the iterative processing of the output result by the Newton-Raphson method to obtain the reference solution point includes: A nonlinear equation group is constructed according to Kirchhoff's voltage law and the output result, and the nonlinear equation group is iteratively processed to obtain a Jacobian matrix. The Newton-Raphson method obtains the reference solution point based on the Jacobian matrix in each iteration process.

[0009] As one preferred solution, the calculation process of the stability region boundary includes: The variable of the reference solution point obtained by the Newton-Raphson method is brought into the circuit topology structure to construct a Lyapunov function, and the derivative of the Lyapunov function is calculated using the Lyapunov function method, so that the boundary of the stable domain is determined when the derivative of the Lyapunov function is zero or less than a preset threshold.

[0010] As one of the preferred solutions, before outputting the final disconnection priority according to the voltage stability margin of the reference disconnection boundary, the post-disaster islanding division method of the power system further includes: The voltage critical value and the actual voltage amplitude of the reference disconnection boundary in the target distribution network are obtained, and the voltage stability margin of the reference disconnection boundary is calculated, wherein the process of obtaining the voltage critical value of the reference disconnection boundary is configured to solve the voltage critical value when the derivative of the Lyapunov function is zero according to the constraints of the circuit topology structure when using the Lyapunov function method to estimate the stability domain.

[0011] As one of the preferred solutions, after determining the active disconnection area of ​​the target distribution network based on the active disconnection boundary, the post-disaster island division method of the power system further includes: The grid power flow data of the active splitting area is simulated based on the Newton-Raphson method. If the local power flow is abnormal, the node power-voltage amplitude curve of the active splitting area is calculated according to the voltage stability analysis to optimize the active splitting area.

[0012] As one of the preferred solutions, the abnormal local power flow conditions include one or more of the following: the power flow value on the line exceeds the rated current carrying capacity, the voltage amplitude of the node exceeds the rated voltage and the power is unbalanced.

[0013] Another embodiment of the present invention provides a post-disaster islanding system for a power system, comprising: The simulation module is used to simulate and analyze the acquired disaster data of the disaster area and the initial power data of the target distribution network to determine the circuit topology structure that currently meets the normal operation requirements; An acquisition module, used to construct a power grid simulation operation model based on the circuit topology structure, and obtain an output result of the power grid simulation operation model; An iteration module, configured to iteratively process the output result using a Newton-Raphson method to obtain a reference decoupling point, and determine a reference decoupling boundary according to the reference decoupling point; wherein the reference decoupling boundary is configured to perform a stability domain boundary calculation on a variable at the reference decoupling point according to a stability domain estimation to obtain the reference decoupling boundary; An output module, used for outputting a final decoupling priority according to a voltage stability margin of the reference decoupling boundary; A determination module, configured to determine an active disconnection boundary under different disaster conditions based on a selected standard condition and the disconnection priority, and determine an active disconnection area of ​​the target distribution network based on the active disconnection boundary; An execution module is used to execute a disconnection strategy corresponding to the active disconnection area matching the disaster conditions during the division of the post-disaster isolated power grid of the target distribution network.

[0014] Compared with the prior art, the embodiments of the present invention have the following advantages: (1) This method uses the Newton-Raphson method for iterative processing to obtain the reference disconnection point, which provides accurate initial data for the stability domain estimation. The stability domain estimation calculates the stability domain boundary based on the variables at these reference disconnection points, thereby accurately determining the reference disconnection boundary. The combination of the Newton-Raphson method and the stability domain estimation enables the key position that causes system instability to be accurately found in the power grid, providing a reliable basis for the disconnection operation of the power grid. (2) Stability domain estimation can evaluate the stability of the power grid as a whole. By calculating the boundary of the stability domain, the stability range of the power grid under different operating conditions can be determined, thereby optimizing the islanding process of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG1 is a schematic flow chart of a method for dividing isolated islands after a disaster in a power system in one embodiment of the present invention; FIG. 2 is a schematic diagram of the structure of a post-disaster island partitioning system for a power system in one embodiment of the present invention.

[0016] Reference numerals: Among them, 11, simulation module; 12, acquisition module; 13, iteration module; 14, output module; 15, determination module; 16, execution module. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] In the description of this application, the terms "first", "second", "third", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0019] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. The terms "vertical", "horizontal", "left", "right", "upper", "lower" and similar expressions used herein are only for illustrative purposes, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0020] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0021] An embodiment of the present invention provides a method for dividing isolated islands after a disaster in a power system. Specifically, please refer to FIG. 1 , which shows a flow chart of a method for dividing isolated islands after a disaster in a power system in one embodiment of the present invention. The method includes: S1: Simulate and analyze the disaster data of the disaster area and the initial power data of the target distribution network to determine the circuit topology that currently meets the normal operation requirements; S2: constructing a power grid simulation operation model based on the circuit topology structure, and obtaining an output result of the power grid simulation operation model; S3: Iteratively process the output result using the Newton-Raphson method to obtain a reference decoupling point, and determine a reference decoupling boundary according to the reference decoupling point; wherein the reference decoupling boundary is configured to perform a stability domain boundary calculation on the variable at the reference decoupling point according to a stability domain estimation to obtain the reference decoupling boundary; S4: outputting a final decoupling priority according to the voltage stability margin of the reference decoupling boundary; S5: determining active disconnection boundaries under different disaster conditions based on the selected standard conditions and the disconnection priority, and determining an active disconnection area of ​​the target distribution network based on the active disconnection boundaries; S6: During the division of the target distribution network into islanded power grids after a disaster, executing a disconnection strategy corresponding to the active disconnection area matching the disaster conditions.

[0022] In S1, the disaster data of the disaster area and the initial power data of the target distribution network are obtained, wherein the disaster data are different under different disaster conditions. Taking flood disaster as an example, the disaster data obtained include flooding water level parameters and flooding time parameters, etc. The initial power data of the target distribution network includes power grid operation data and equipment monitoring data of substations, etc. After preprocessing these data, the preprocessing steps include data cleaning, disaster data standardization and initial power data normalization. Using simulation software such as MATLAB / Simulink, PSCAD / EMTDC, OpenDSS, etc., simulation analysis is performed on these data, and the geographical scope of the disaster area and the geographical location of the target distribution network are spatially superimposed and analyzed to determine the power facilities affected by the disaster in the target distribution network, and the power flow parameters of the power facilities are calculated based on the fast decoupling power flow algorithm. Based on the power facilities and the power flow parameters, a circuit topology structure that currently meets the normal operation requirements is constructed. The circuit topology structure is the basis of the power grid simulation operation model, which can describe in detail the connection relationship between various components (such as generators, transformers, lines, loads, etc.) in the power grid under natural disaster conditions.

[0023] Specifically, taking flood disasters as an example, the preprocessing of disaster data can accurately locate the position of electric poles buried by mudslides through high-resolution satellite images, and the close-range inspection of drones can clearly show the damage and deformation details of the substation equipment casing, assisting in judging the impact of internal components; the preprocessing of the initial power data of the target distribution network can be done by cross-checking the initial power data from different sources using a data verification algorithm, eliminating outliers and filling missing values; using the Grubbs criterion based on statistical principles to identify outliers in current and power data; with the help of interpolation method, based on the parameters of the surrounding normal nodes, the key node voltage data missing due to sensor failure is supplemented to ensure that the circuit topology structure corresponds to the current normal operation requirements.

[0024] For the local power grid where the power facilities affected by the disaster are located, the corresponding node admittance matrix is ​​constructed. The node admittance matrix reflects the electrical connection relationship between nodes in the power grid and the electrical parameters (such as conductance, susceptance, reactance, etc.) of components such as lines and transformers, and is the basic data structure for power flow calculation.

[0025] The fast decoupled power flow algorithm is used for iterative calculation, and finally the voltage amplitude and phase angle of each node and the power flow parameters such as active power and reactive power of each line are obtained. Based on the power facilities and power flow parameters, the circuit topology structure that meets the normal operation requirements is constructed.

[0026] By constructing a power grid simulation operation model using the circuit topology structure, the output results of the power grid simulation operation model can be obtained.

[0027] Specifically, the steady-state operation of the power grid simulation operation model constructed based on the circuit topology follows the power system flow equation. For a power grid with n nodes, the power flow equation in polar coordinate form is often used to describe it, and the node power equation can be written as: For the load node, the active power equation is: The reactive power equation is: Among them, , is the injected active and reactive power of node i, is the voltage amplitude of the node, is the voltage phase difference between node i and node j, and are the real and imaginary elements of the node admittance matrix, respectively.

[0028] For the generator node, the active power is known and voltage amplitude , the above active power equation and the supplementary voltage amplitude constraint equation are solved simultaneously.

[0029] Among them, the voltage amplitude constraint equation is ,in is the set value of the node voltage amplitude.

[0030] Based on the power grid simulation operation model, simulation conditions are set, including normal operation, anticipated faults (line short circuit, generator tripping, etc.), load peak impact scenarios, etc. The model outputs multiple results, including the voltage amplitude and phase angle of each node, as well as the line power flow direction and size, etc., which help to detect overload hazards and voltage over-limit problems.

[0031] In S3, a nonlinear equation group is constructed according to Kirchhoff's voltage law and the output results of the power grid simulation operation model, and the nonlinear equation group is iteratively processed to obtain a Jacobian matrix. The Newton-Raphson method obtains the reference solution point based on the Jacobian matrix in each iteration process. The specific calculation process is as follows.

[0032] Specifically, Kirchhoff's voltage law states that in any closed loop, the algebraic sum of the voltage drops on each component is equal to zero. For the circuit topology of the power system, this means that along each closed loop in the power grid, the voltage equations listed based on the characteristics of the components such as resistance, reactance corresponding to the voltage drop and the electromotive force of the power supply must satisfy the condition of a total sum of zero. Therefore, a nonlinear set of equations is constructed based on Kirchhoff's voltage law and the output results of the power grid simulation operation model.

[0033] In order to solve the nonlinear equations constructed above, an iterative method is usually used. The Newton-Raphson method is a commonly used efficient iterative algorithm. Its core idea is to first give the initial values ​​of the variables in the equations, and then gradually approach the exact solution of the equations by continuously correcting the initial values.

[0034] In each iteration process, it is necessary to calculate the partial derivatives of each equation in the nonlinear equation group with respect to each variable, and arranging these partial derivatives according to certain rules constitutes the Jacobian matrix.

[0035] After obtaining the Jacobian matrix, the Newton-Raphson method is used to iterate the variables. For the above nonlinear equations, let the variable vector be , the equation vector is , the Jacobian matrix is , then the iteration formula is: in, Indicates the number of iterations.

[0036] By repeating this iterative process continuously until certain convergence conditions are met, the variable values ​​obtained at this time are the solutions to the system of equations.

[0037] After the iteration converges, the obtained electrical quantities such as voltage and current of each node are analyzed. Nodes that present special conditions, such as voltage amplitude close to the lower limit allowed by the system (if the voltage is too low, the equipment will not be able to operate normally), line flow approaching the thermal stability limit (that is, the transmission power is close to the maximum power that the line can carry), or the Jacobian matrix is ​​close to singular (which means that the system is in a very unstable state, and a small disturbance may cause a large change) will be marked as reference decoupling points. Once the area where these points are located has abnormal conditions such as faults, the power grid is likely to become unstable, which is a key vulnerable part of the power grid structure.

[0038] In S3, the stability domain boundary is calculated for the variable at the reference solution point according to the stability domain estimate to obtain the reference solution boundary.

[0039] Specifically, the stability region estimation is based on the relevant theories of power system stability. The power system is regarded as a dynamic system. After being disturbed, the trajectory of the system state variables over time determines whether the system can maintain stable operation. The system state variables include those voltages, currents, phase angles, etc. at the reference decoupling point. If the trajectory of the system state variables can eventually converge to a stable equilibrium point, then the system is stable; conversely, if the trajectory diverges or enters an uncontrollable state, the system will be unstable.

[0040] The variables of the reference solution points obtained by the Newton-Raphson method are used to construct the Lyapunov function. The derivative of the Lyapunov function is calculated using the Lyapunov function method, and is set equal to zero or less than a certain threshold to determine the boundary of the stable domain.

[0041] At the same time, the voltage stability margin of the reference disconnection boundary can be calculated according to the voltage critical value when the derivative of the Lyapunov function is zero and the actual voltage amplitude in the target distribution network, and the disconnection priority can be determined with reference to its voltage stability margin.

[0042] Specifically, the voltage stability margin is an indicator to measure the voltage stability of the power system. It indicates how much safety margin the system has from the voltage instability state under the current operating state. Simply put, it is the degree of disturbance (such as load increase, generator failure, etc.) that the system can withstand without causing voltage collapse.

[0043] When determining the active disconnection area and disconnection strategy, areas with lower voltage stability margins are more likely to experience voltage instability when the system is disturbed, so they will be given priority in the disconnection priority sorting. For example, when a fault occurs, priority is given to disconnecting those areas where the voltage stability margin is close to zero, isolating the unstable part from the main grid, preventing the fault from spreading, and ensuring the power supply safety of other areas.

[0044] Under different disaster conditions, the priority of decoupling is different. The priority of decoupling can also be controlled manually or through different considerations, such as load importance and disaster type targeting. Taking load importance as an example, different types of loads are distinguished. Hospitals, fire protection, transportation hubs, etc. that are related to public safety and emergency rescue are classified as first-level critical loads, and power supply must be guaranteed first; general industrial enterprises, large commercial centers, etc. can be classified as second-level loads. Power outages will bring certain economic losses, but they can be relatively tolerated within a certain period of time; ordinary residential communities, etc. are classified as third-level loads, and the impact of power outages is mainly in terms of living convenience. According to this load classification, when determining the active decoupling boundary, priority is given to ensuring stable power supply in the area where the critical load is located, and it is reasonably included or excluded in different active decoupling areas.

[0045] Around high-priority nodes and areas, the initial active disconnection boundary is drawn according to their electrical connection characteristics, surrounding power grid topology, etc. Subsequently, dynamic adjustments are made based on the situation of low-priority areas. For example, when the risk of fault propagation increases due to changes in the surrounding environment (such as adjacent line faults causing power flow transfer and exposing it to new risks), the active disconnection boundary is expanded in a timely manner to ensure that the boundary can cover all areas that may be unstable under disaster conditions and require disconnection operations, thereby accurately determining the active disconnection area of ​​the target distribution network.

[0046] It is also possible to simulate the grid flow data of the active splitting area based on the Newton-Raphson method. If the local flow is abnormal, the node power-voltage amplitude curve of the active splitting area is calculated according to the voltage stability analysis to optimize the active splitting area.

[0047] The local power flow abnormality includes one or more of the following: the power flow value on the line exceeds the rated current carrying capacity, the voltage amplitude of the node exceeds the rated voltage and the power imbalance, wherein the power imbalance includes active power imbalance and reactive power imbalance.

[0048] An embodiment of the present invention provides a post-disaster islanding system for a power system. Specifically, please refer to FIG. 2 , which shows a schematic diagram of the structure of a post-disaster islanding system for a power system in one embodiment of the present invention. The system includes: The simulation module 11 is used to simulate and analyze the acquired disaster data of the disaster area and the initial power data of the target distribution network to determine the circuit topology structure that currently meets the normal operation requirements; An acquisition module 12 is used to construct a power grid simulation operation model based on the circuit topology structure and obtain an output result of the power grid simulation operation model; An iterative module 13 is used to iteratively process the output result using the Newton-Raphson method to obtain a reference decoupling point, and determine a reference decoupling boundary according to the reference decoupling point; wherein the reference decoupling boundary is configured to perform a stable domain boundary calculation on the variable at the reference decoupling point according to a stable domain estimation to obtain the reference decoupling boundary; An output module 14, configured to output a final decoupling priority according to a voltage stability margin of the reference decoupling boundary; A determination module 15, configured to determine an active disconnection boundary under different disaster conditions based on a selected standard condition and the disconnection priority, and determine an active disconnection area of ​​the target distribution network based on the active disconnection boundary; The execution module 16 is used to execute the disconnection strategy corresponding to the active disconnection area matching the disaster conditions during the division process of the post-disaster isolated power grid of the target distribution network.

[0049] Compared with the prior art, the embodiments of the present invention have the following advantages: (1) This method uses the Newton-Raphson method for iterative processing to obtain the reference disconnection point, which provides accurate initial data for the stability domain estimation. The stability domain estimation calculates the stability domain boundary based on the variables at these reference disconnection points, thereby accurately determining the reference disconnection boundary. The combination of the Newton-Raphson method and the stability domain estimation enables the key position that causes system instability to be accurately found in the power grid, providing a reliable basis for the disconnection operation of the power grid. (2) Stability region estimation can evaluate the stability of the power grid as a whole. By calculating the boundary of the stability region, the stability range of the power grid under different operating conditions can be determined, thereby formulating a more reasonable power grid control strategy.

[0050] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for dividing isolated islands after a disaster in a power system, characterized in that: include: Conduct simulation analysis on the acquired disaster data of the disaster area and the initial power data of the target distribution network to determine the circuit topology structure that currently meets the normal operation requirements; Building a power grid simulation operation model based on the circuit topology structure, and obtaining an output result of the power grid simulation operation model; Iteratively processing the output result using the Newton-Raphson method to obtain a reference decoupling point, and determining a reference decoupling boundary according to the reference decoupling point; wherein the reference decoupling boundary is configured to perform a stability domain boundary calculation on a variable at the reference decoupling point according to a stability domain estimation to obtain the reference decoupling boundary; Outputting a final decoupling priority according to the voltage stability margin of the reference decoupling boundary; Determine active disconnection boundaries under different disaster conditions based on the selected standard conditions and the disconnection priority, and determine active disconnection areas of the target distribution network based on the active disconnection boundaries; During the division of the target distribution network into islanded power grids after a disaster, a disconnection strategy corresponding to the active disconnection area matching the current disaster conditions is executed.

2. The post-disaster island division method for a power system according to claim 1, characterized in that: Before simulating and analyzing the acquired disaster affected data of the disaster area and the initial power data of the target distribution network, the post-disaster island division method of the power system further includes: The disaster-affected data of the disaster area and the initial power data of the target power distribution network are preprocessed, and the preprocessing steps include data cleaning, standardization of the disaster-affected data and normalization of the initial power data.

3. The post-disaster islanding method for a power system according to claim 1, characterized in that: The construction process of the circuit topology structure includes: Perform spatial overlay analysis on the geographical scope of the disaster area and the geographical location of the target distribution network to determine the power facilities in the target distribution network affected by the disaster; The power flow parameters of the power facility are calculated based on a fast decoupling power flow algorithm, and a circuit topology structure corresponding to the current normal operation requirements is constructed based on the power facility and the power flow parameters.

4. The post-disaster islanding method for a power system according to claim 1, characterized in that: The output results of the power grid simulation operation model include one or more of the following: node voltage amplitude, phase angle, current and line power flow direction and magnitude.

5. The post-disaster islanding method for a power system according to claim 1, characterized in that: The iterative processing of the output result by the Newton-Raphson method to obtain a reference solution point includes: A nonlinear equation group is constructed according to Kirchhoff's voltage law and the output result, and the nonlinear equation group is iteratively processed to obtain a Jacobian matrix. The Newton-Raphson method obtains the reference solution point based on the Jacobian matrix in each iteration process.

6. The post-disaster island division method for a power system according to claim 1, characterized in that: The calculation process of the stability region boundary includes: The variable of the reference solution point obtained by the Newton-Raphson method is brought into the circuit topology structure to construct a Lyapunov function, and the derivative of the Lyapunov function is calculated using the Lyapunov function method, so that the boundary of the stable domain is determined when the derivative of the Lyapunov function is zero or less than a preset threshold.

7. The post-disaster islanding method for a power system according to claim 1, characterized in that: Before outputting the final disconnection priority according to the voltage stability margin of the reference disconnection boundary, the post-disaster islanding division method of the power system further includes: The voltage critical value and the actual voltage amplitude of the reference disconnection boundary in the target distribution network are obtained, and the voltage stability margin of the reference disconnection boundary is calculated, wherein the process of obtaining the voltage critical value of the reference disconnection boundary is configured to solve the voltage critical value when the derivative of the Lyapunov function is zero according to the constraints of the circuit topology structure when using the Lyapunov function method to estimate the stability domain.

8. The method for dividing isolated islands after a disaster in a power system according to claim 1, characterized in that: After determining the active disconnection area of ​​the target distribution network based on the active disconnection boundary, the post-disaster island division method of the power system further includes: The grid power flow data of the active splitting area is simulated based on the Newton-Raphson method. If the local power flow is abnormal, the node power-voltage amplitude curve of the active splitting area is calculated according to the voltage stability analysis to optimize the active splitting area.

9. The method for dividing isolated islands after a disaster in a power system according to claim 8, characterized in that: The local power flow abnormality includes one or more of the following: the power flow value on the line exceeds the rated current carrying capacity, the voltage amplitude of the node exceeds the rated voltage and the power is unbalanced.

10. A post-disaster islanding system for a power system, characterized in that: include: The simulation module is used to simulate and analyze the acquired disaster data of the disaster area and the initial power data of the target distribution network to determine the circuit topology structure that currently meets the normal operation requirements; An acquisition module, used to construct a power grid simulation operation model based on the circuit topology structure, and obtain an output result of the power grid simulation operation model; An iteration module, configured to iteratively process the output result using a Newton-Raphson method to obtain a reference decoupling point, and determine a reference decoupling boundary according to the reference decoupling point; wherein the reference decoupling boundary is configured to perform a stability domain boundary calculation on a variable at the reference decoupling point according to a stability domain estimation to obtain the reference decoupling boundary; An output module, used for outputting a final decoupling priority according to a voltage stability margin of the reference decoupling boundary; A determination module, configured to determine an active disconnection boundary under different disaster conditions based on a selected standard condition and the disconnection priority, and determine an active disconnection area of ​​the target distribution network based on the active disconnection boundary; An execution module is used to execute a disconnection strategy corresponding to the active disconnection area matching the current disaster conditions during the division of the post-disaster isolated island power grid of the target distribution network.

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