Power grid state estimation method and device based on load flow calculation, medium and equipment

Abstract

The invention discloses a power grid state estimation method and device based on load flow calculation, a medium and equipment, and relates to the technical field of power grid system state data processing, and the method comprises the following steps: obtaining and analyzing power grid system state data of a historical regulation and control system to obtain an initial condition of load flow calculation, the power grid system state data comprises first power grid state estimation data and second provincial dispatching power grid operation boundary data; carrying out load flow calculation on the initial condition by combining a CapG load flow calculation module to obtain a Jacobian matrix; performing matrix operation on the Jacobian matrix to obtain a power grid state sensitivity matrix; and applying the power grid state sensitivity matrix to a power grid optimization and fault analysis system.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid state estimation methods based on power flow calculation, and more specifically, the present invention relates to a power grid state estimation method, device, medium and equipment based on power flow calculation. Background Art

[0002] The power system is one of the most complex systems in the world, with high nonlinearity and dimensional complexity. The most critical state variable of the power system is the voltage vector of each node in the power grid. The voltage is the variation of the power frequency, including the amplitude and phase of the voltage. The calculation of voltage is also an important issue in the operation of the power grid.

[0003] For voltage, more information can be obtained when calculating power flow, such as the Jacobian matrix, which reflects the relationship between active power, reactive power and the real part, imaginary part or amplitude phase of voltage. Therefore, it is worthwhile to further explore the voltage calculation method through basic knowledge, use the existing data files in the power grid, quickly calculate the mathematical information related to voltage, and provide the dispatcher with a reference strategy for real-time voltage adjustment.

[0004] In the existing real-time operation system of the power grid, firstly, the voltage calculation ability is insufficient, there are no effective methods and tools, and the voltage calculation depends on the system flow calculation. At present, the actual power grid uses BPA for offline calculation, and the input data are all typical offline data, which is quite different from the actual operation data, resulting in inaccurate voltage analysis; secondly, due to the difficulty in voltage calculation and analysis, it is difficult to form a voltage adjustment strategy. When the voltage of a certain node in the system is too high or too low, the power grid dispatcher has no effective means to make quick and accurate adjustments. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a method, device, medium and equipment for estimating the state of a power grid based on power flow calculation, which solves the problem in the prior art that voltage regulation is insufficient according to manual experience in power grid dispatching by processing the power grid system state data.

[0006] To achieve the above object, the present invention provides the following technical solutions: A power grid state estimation method based on power flow calculation comprises the following steps: acquiring power grid system state data of a historical control system and parsing it to obtain initial conditions for power flow calculation, wherein the power grid system state data comprises first power grid state estimation data and second provincial power grid operation boundary data; performing power flow calculation on the initial conditions in combination with a Cap_G power flow calculation module to obtain a Jacobian matrix; performing matrix operations on the Jacobian matrix to obtain a power grid state sensitivity matrix; and applying the power grid state sensitivity matrix to a power grid optimization and fault analysis system.

[0007] In a preferred embodiment, the first grid state estimation data includes model parameters, model modeling timestamps and measurement data of all equipment in the grid, and the model parameters of all equipment in the grid include grid node voltage amplitude, phase angle and line power flow; the second provincial dispatching grid operation boundary data includes maintenance plan data, provincial dispatching unit power generation plan data, provincial dispatching bus load forecast data, interconnection line port plan data, and system load forecast data.

[0008] In a preferred embodiment, the acquisition of the power grid system status data of the historical control system is carried out, specifically: obtaining the first power grid status estimation data derived from the network control system and the provincial control system, and integrating the first power grid status estimation data; splicing and constructing an external network model based on the first power grid status estimation data derived from the network control system and the provincial control system; obtaining the second provincial power grid operation boundary data, combining the first power grid status estimation data and the external network model, to obtain the initial conditions for the flow calculation.

[0009] In a preferred embodiment, the initial conditions for the flow calculation are obtained by the following method: according to the maintenance plan data, the commissioning and decommissioning equipment of the power grid equipment in the future time period is obtained; the commissioning and decommissioning equipment of the power grid equipment in the future time period is found in the external network model, and the disconnection processing is performed in the planned time period to obtain the first initial condition; based on the first power grid state estimation data, the first initial condition is used to calculate the measurement data of the historical planned time period corresponding to the planned time period, and the measurement data of the historical planned time period is superimposed on the external network model to obtain the future form of the external network model; based on the provincial dispatching unit power generation plan data, the provincial dispatching bus load forecast data, the interconnection line port plan data and the system load forecast data, the first initial condition is used to calculate the measurement data of the historical planned time period, and the measurement data of the historical planned time period is superimposed on the model of the equipment in the network dispatching power grid to obtain the future form of the model of the equipment in the network dispatching power grid; the initial conditions for the flow calculation are generated according to the future form of the external network model and the future form of the model of the equipment in the network dispatching power grid.

[0010] In a preferred embodiment, the first power grid state estimation data exported by the network control system and the provincial control system is spliced ​​to construct an external network model, specifically: determining the boundary equipment between the network control grid and the provincial control grid, and determining the plant station of the boundary equipment; determining the boundary range according to the connection between the boundary equipment and the plant station; deleting the equipment outside the boundary range in the provincial control grid; deleting the equipment within the boundary range in the network control grid; and generating an external network model by splicing the model parameters and measurement data of the equipment that has not been deleted.

[0011] In a preferred embodiment, the Cap_G power flow calculation module is combined to perform power flow calculation on the initial conditions of the power flow calculation, specifically: determining the node type of each node in the power grid, the node type including PQ node, PV node, and balance node; constructing a power flow equation based on the initial conditions of the power flow calculation; linearizing the power flow equation in combination with the initial Jacobian matrix, and obtaining the final Jacobian matrix after convergence through the Newton-Raphson method.

[0012] In a preferred embodiment, a device using the power grid state estimation method based on power flow calculation as described in any one of claims 1 to 7 is characterized in that it includes: a data acquisition module: used to acquire and analyze the power grid system state data of the historical control system to obtain the initial conditions for the power flow calculation, the power grid system state data including the first power grid state estimation data and the second provincial power grid operation boundary data; a power flow calculation module: used to perform power flow calculation on the initial conditions in combination with the Cap_G power flow calculation module to obtain the Jacobian matrix; a sensitivity matrix calculation module: used to perform matrix operations on the Jacobian matrix to obtain a power grid state sensitivity matrix; an optimization and fault analysis module: used to apply the power grid state sensitivity matrix to the optimization and fault analysis system of the power grid.

[0013] The technical effects and advantages of a power grid state estimation method, device, medium and equipment based on power flow calculation of the present invention are as follows: 1. The present invention achieves quantitative and accurate calculation of the sensitivity relationship between each node voltage and the node power, thereby solving the problem of inaccurate voltage regulation based on manual experience in power grid dispatching in the prior art.

[0014] 2. The present invention uses rigorous matrix operations to accurately determine that each unit change in active power or reactive power at any node in the power grid reduces the impact on the voltage amplitude of the node of concern.

[0015] 3. By splicing the models of the grid-controlled power grid and the provincial power grid, an external grid model is constructed, thereby ensuring accurate modeling of the grid connection part, improving the accuracy of the external grid model, and enhancing the accuracy of the power flow calculation results.

[0016] 4. The calculation of the grid state sensitivity matrix can more accurately reflect the relationship between the voltage amplitude and power of the node, making the grid optimization and fault analysis more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a flow chart of a method for estimating a power grid state based on power flow calculation according to the present invention; Figure 2 The present invention is a functional module diagram of a device for a power grid state estimation method based on power flow calculation.

[0018] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0019] 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. 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.

[0020] Embodiment 1, Figure 1 A flow chart of a method for estimating a power grid state based on power flow calculation of the present invention is given. In this embodiment, the method for estimating a power grid state based on power flow calculation comprises the following steps: S1, acquiring and analyzing the power grid system status data of the historical control system to obtain the initial conditions for power flow calculation, wherein the power grid system status data includes first power grid status estimation data and second provincial power grid operation boundary data; S2, combine the Cap_G power flow calculation module to perform power flow calculation on the initial conditions and obtain the Jacobian matrix; S3, performing matrix operation on the Jacobian matrix to obtain a power grid state sensitivity matrix; S4, applying the power grid state sensitivity matrix to a power grid optimization and fault analysis system.

[0021] The first grid state estimation data includes model parameters, model modeling timestamps and measurement data of all devices in the grid, and the model parameters of all devices in the grid include grid node voltage amplitude, phase angle and line power flow; The second provincial dispatching power grid operation boundary data includes maintenance plan data, provincial dispatching unit power generation plan data, provincial dispatching bus load forecast data, interconnection line port plan data, and system load forecast data.

[0022] The method for obtaining the power grid system status data of the historical control system is as follows: Obtaining first grid state estimation data in the form of QS files, and sorting the data according to file generation timestamps; Saving the sorted first power grid state estimation data in the form of a QS file in a designated directory to which the QS file belongs; Get the QS files from the specified directory to which they belong and parse them in sorted order.

[0023] The power grid system status data of the historical control system is obtained and analyzed. The purpose of the analysis is to convert the power grid system status data into an input format suitable for power flow calculation. The analysis process is as follows: Acquire first power grid state estimation data derived from the network control system and the provincial control system, and perform integrated identification on the first power grid state estimation data; splicing and constructing an external network model according to the first power grid state estimation data derived from the network control system and the provincial control system; The operation boundary data of the second provincial power grid is obtained, and the initial conditions for power flow calculation are obtained by combining the first power grid state estimation data and the external network model.

[0024] The initial conditions for the power flow calculation are obtained as follows: According to the maintenance plan data, the commissioning and decommissioning equipment of the power grid equipment in the future period is obtained; Find the commissioning and decommissioning equipment of the power grid equipment in the future period in the external network model, and perform disconnection processing in the planned period to obtain the first initial condition; Based on the first power grid state estimation data, using the first initial condition to calculate the measurement data of the historical planning period corresponding to the planning period, superimposing the measurement data of the historical planning period into the external network model to obtain the future form of the external network model; Based on the provincial dispatching unit power generation plan data, the provincial dispatching bus load forecast data, the tie line port sub-plan data and the system load forecast data, the first initial condition is used to calculate the measurement data of the historical planning period, and the measurement data of the historical planning period is superimposed on the model of the equipment in the network dispatching power grid to obtain the future form of the model of the equipment in the network dispatching power grid; The initial conditions for power flow calculation are generated according to the future form of the external network model and the future form of the model of the equipment in the network control power grid.

[0025] It should be noted that the integrated identification of the first power grid state estimation data can ensure that the identification of each of the devices is unique.

[0026] The significance and role of integrated representation processing are mainly reflected in: Data integration and consistency: Eliminate data differences between different control systems and ensure data consistency; Improved grid modeling accuracy: Ensure that the grid model can truly reflect the actual status and improve the accuracy of power flow calculation; External network splicing and boundary definition: Supports the splicing of external network models and accurate definition of power grid boundaries to ensure accurate modeling of the connected parts of the power grid; Optimization of calculation efficiency and accuracy: Improve the accuracy and efficiency of power flow calculation; Support dispatching and optimization decisions: Provide basic data for real-time dispatching and power grid optimization to ensure the safe and stable operation of the power grid.

[0027] The first power grid state estimation data derived from the network control system and the provincial control system are spliced ​​to construct an external network model, specifically: Determine the boundary equipment between the network dispatching power grid and the provincial dispatching power grid, and determine the plant station of the boundary equipment; Determining a boundary range according to a connection line between the boundary equipment and the plant station; Deleting equipment outside the boundary range in the provincial power grid; Deleting equipment within the boundary range in the network control grid; The external network model is generated based on the model parameters and measurement data of the devices that have not been deleted.

[0028] It should be noted that, in each process of building an external network model, if the model building time of the device to be spliced ​​is the same as the model building time of the last process of building an external network model, only its measurement data will be updated.

[0029] Power flow calculation is a term in electrical engineering, which refers to the calculation of the distribution of active power, reactive power and voltage in the power grid under given power system network topology, component parameters, and power generation and load parameters.

[0030] The Cap_G power flow calculation module is combined to perform power flow calculation on the initial conditions of power flow calculation, specifically: Determine the node type of each node in the power grid, wherein the node type includes a PQ node, a PV node, and a balancing node; Based on the initial conditions of the power flow calculation, construct a power flow equation; The power flow equation is linearized in combination with the initial Jacobian matrix, and the final Jacobian matrix is ​​obtained after convergence through the Newton-Raphson method.

[0031] It should be noted that the PQ node is a node with known active power and reactive power, but unknown voltage amplitude and phase angle, and the voltage amplitude is a fixed value; the PV node is a node with known active power and voltage amplitude, but unknown reactive power and phase angle; the balancing node is a reference node of the power grid, the voltage amplitude and phase angle of the balancing node are known, and the power balance of other nodes is supplied by the power of the balancing node.

[0032] It should be noted that before calculating the power flow, because it is necessary to examine the relationship between the voltage amplitude of the node in the power grid and the active power and reactive power of any other node, the other arbitrary nodes to be examined must be PQ nodes and should not be set to PV nodes.

[0033] The power flow equation of the power system can be described by Kirchhoff's voltage law and Kirchhoff's current law. The power flow equation is defined as follows:

[0034] Where: is the active power of the ith node, is the reactive power of the ith node, is the voltage amplitude of the ith node, is the voltage amplitude of the jth node, is the phase angle of the ith node, is the phase angle of the jth node, is the real part of the admittance matrix of branch ij, is the imaginary part of the admittance matrix of branch ij.

[0035] It should be noted that admittance is a physical quantity in the circuit and is the reciprocal of impedance; the real part of the admittance matrix is ​​called the conductivity of the admittance; the imaginary part of the admittance matrix is ​​called the admittance of the admittance; therefore, each element of the admittance matrix can represent the electrical connection relationship between two different branches in the circuit (such as transformers, transmission lines, loads, etc.).

[0036] The Jacobian matrix is ​​the partial derivative of the power flow equation with respect to the voltage phase angle and the voltage amplitude. The Jacobian matrix is ​​defined as follows:

[0037] Where: is the Jacobian matrix, is the partial derivative of the active power of the i-th node with respect to the phase angle of the j-th node, is the partial derivative of the active power of the i-th node with respect to the voltage amplitude of the j-th node, is the partial derivative of the reactive power of the i-th node with respect to the phase angle of the j-th node, is the partial derivative of the reactive power of the i-th node with respect to the voltage amplitude of the j-th node, is the active power of the ith node, is the reactive power of the ith node, is the voltage amplitude of the jth node, is the phase angle of the jth node.

[0038] The partial derivative of the active power of the i-th node with respect to the phase angle of the j-th node is calculated as follows:

[0039] The partial derivative of the active power of the i-th node with respect to the voltage amplitude of the j-th node is calculated as follows:

[0040] The partial derivative of the reactive power of the i-th node with respect to the phase angle of the j-th node is calculated as follows:

[0041] The partial derivative of the reactive power of the i-th node with respect to the voltage amplitude of the j-th node is calculated as follows:

[0042] Where: is the active power of the ith node, is the reactive power of the ith node, is the active power of the jth node, is the reactive power of the jth node, is the voltage amplitude of the ith node, is the voltage amplitude of the jth node, is the phase angle of the ith node, is the phase angle of the jth node, is the real part of the admittance matrix of branch ij, is the imaginary part of the admittance matrix of branch ij.

[0043] Power flow calculation is the calculation of steady-state operating parameters of each part of the power system based on the given grid structure, parameters and operating conditions of generators, loads and other components. Usually the given operating conditions include the power of each power source and load point in the system, the voltage of the hub point, the voltage and phase angle of the balance point. The operating state parameters to be calculated include the voltage amplitude and phase angle of each bus node of the power grid, the power distribution of each branch, the power loss of the network, etc.

[0044] The power flow calculation module has the following functions and uses: Analyze the steady-state performance of the power system: The power flow calculation module is used to analyze the steady-state performance of the power system under various operating conditions. It is a basic analysis tool for planning, designing and operating transmission and distribution systems and industrial distribution networks. ‌Detect whether power components are overloaded‌: Through power flow calculation, it is possible to detect whether each power component is overloaded to ensure safe operation of the system; ‌Check bus voltage‌: Check whether the bus voltage in the system meets the power supply requirements and ensure that the voltage is within the allowable range; ‌Adjust the grid operation mode‌: During the operation of the grid, adjust the grid operation mode according to the power flow calculation results to deal with grid failures or defects; ‌Provide planning basis‌: According to the calculated values ​​of power flow (power, voltage), provide basis for power system planning, protection setting, conductor cross-sectional area selection, etc. ‌

[0045] The Newton-Raphson method, also known as the Newton iteration method, is a numerical optimization method based on the Newton method. The Newton-Raphson method is one of the important methods for finding the roots of an equation. Its greatest advantage is that it has square convergence near a single root of the equation, and the method can also be used to find repeated roots and complex roots of the equation.

[0046] The Jacobian matrix is ​​subjected to matrix operation to obtain a power grid state sensitivity matrix, which is specifically: The Jacobian matrix is ​​inverted to obtain a power grid state sensitivity matrix, which is defined as follows:

[0047] Right now,

[0048] Where: correspond , reflects the relationship between active power and real part of voltage; correspond , reflects the relationship between reactive power and real part of voltage; correspond , reflects the relationship between active power and imaginary part of voltage; correspond , reflects the relationship between reactive power and imaginary part of voltage, is the active power of the ith node, is the reactive power of the ith node, is the active power of the jth node, is the reactive power of the jth node, is the voltage amplitude of the ith node, is the voltage amplitude of the jth node, is the phase angle of the ith node, is the phase angle of the jth node, is the phase angle of the kth node.

[0049] It should be noted that, from a formal point of view, the positions of the relationships represented by the main diagonal elements of the grid state sensitivity matrix have not changed, but the positions of the elements of the relationships represented by the secondary diagonal elements have been swapped relative to the Jacobian matrix.

[0050] The grid state sensitivity matrix is ​​applied to the optimization and fault analysis system of the grid, which can reflect the precise relationship between the voltage amplitude of the node and the reactive power and active power of the node, and can be used for precise voltage adjustment of the grid. The grid state sensitivity matrix represents the change in the voltage of the i-th node caused by the power change of the j-th node.

[0051] like Figure 2As shown, it is a functional module diagram of a device for processing power grid system status data. According to the functions to be implemented, the device for a power grid state estimation method based on power flow calculation may include a data acquisition module, a power flow calculation module, a sensitivity matrix calculation module, and an optimization and fault analysis module. The module described in the present invention may also be referred to as a unit, which refers to a series of computer program segments that can be executed by a processor of a device for a power grid state estimation method based on power flow calculation and can complete fixed functions, which are stored in the memory of the device for processing power grid system status data.

[0052] In this embodiment, the functions of each module / unit are as follows: Data acquisition module: used to acquire and analyze the power grid system status data of the historical control system to obtain the initial conditions for power flow calculation, wherein the power grid system status data includes the first power grid status estimation data and the second provincial power grid operation boundary data; Power flow calculation module: used to combine Cap_G power flow calculation module to perform power flow calculation on initial conditions and obtain Jacobian matrix; Sensitivity matrix calculation module: used for performing matrix operation on the Jacobian matrix to obtain a power grid state sensitivity matrix; Optimization and fault analysis module: used for applying the power grid state sensitivity matrix to the optimization and fault analysis system of the power grid.

[0053] In detail, the modules described in the device of the power grid state estimation method based on power flow calculation described in the embodiment of the present invention adopt the same technical means as the power grid state estimation method based on power flow calculation described in the accompanying drawings when used, and can produce the same technical effects, which will not be repeated here.

[0054] The electronic device may include a processor, a memory, a communication bus, and a communication interface, and may also include a computer program stored in the memory and executable on the processor.

[0055] Among them, the processor is the control core (Control Unit) of the electronic device, which uses various interfaces and lines to connect the various components of the entire electronic device, and executes various functions of the electronic device and processes data by running or executing programs or modules stored in the memory and calling data stored in the memory.

[0056] The memory includes at least one type of readable storage medium, and in some embodiments, the memory may be an internal storage unit of the electronic device, such as a mobile hard disk of the electronic device. The memory may be used to store not only application software installed in the electronic device but also various data.

[0057] The communication bus is configured to realize connection and communication between the memory and at least one processor.

[0058] The communication interface is used for communication between the above electronic device and other devices, including a network interface and a user interface.

[0059] The figure only shows an electronic device with components. Those skilled in the art will understand that the structure shown in the figure does not constitute a limitation on the electronic device, and may include fewer or more components than shown in the figure, or combine certain components, or arrange the components differently.

[0060] It should be understood that the embodiment is for illustration only and the scope of the patent application is not limited to this structure.

[0061] The external network model generation program stored in the memory in the electronic device is a combination of multiple instructions, and when running in the processor, the steps in the above-mentioned power grid state estimation method based on power flow calculation can be implemented.

[0062] Specifically, the specific implementation system of the processor for the above instructions can refer to the description of the relevant steps in the corresponding embodiment of the accompanying drawings, which will not be repeated here.

[0063] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor of an electronic device, the steps in the above-mentioned power grid state estimation method based on power flow calculation can be implemented.

[0064] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0065] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0066] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0067] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0068] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0069] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for estimating power grid state based on power flow calculation, characterized in that: The steps include: Acquire and analyze the power grid system status data of the historical control system to obtain the initial conditions for power flow calculation, wherein the power grid system status data includes first power grid state estimation data and second provincial power grid operation boundary data; Combined with the Cap_G power flow calculation module, the power flow calculation of the initial conditions is performed to obtain the Jacobian matrix; Performing matrix operations on the Jacobian matrix to obtain a power grid state sensitivity matrix; The power grid state sensitivity matrix is ​​applied to the optimization and fault analysis system of the power grid.

2. The power grid state estimation method based on power flow calculation according to claim 1, characterized in that: The power grid system state data includes first power grid state estimation data and second provincial power grid operation boundary data, specifically: The first grid state estimation data includes model parameters of all devices in the grid, model modeling timestamps, and measurement data of historical planning periods, wherein the model parameters of all devices in the grid include grid node voltage amplitudes, phase angles, and line power flows; The second provincial dispatching power grid operation boundary data includes maintenance plan data, provincial dispatching unit power generation plan data, provincial dispatching bus load forecast data, interconnection line port plan data, and system load forecast data.

3. The power grid state estimation method based on power flow calculation according to claim 2 is characterized in that: The obtaining and parsing of the power grid system status data of the historical control system is specifically as follows: Acquire first power grid state estimation data derived from the network control system and the provincial control system, and perform integrated identification on the first power grid state estimation data; splicing and constructing an external network model according to the first power grid state estimation data derived from the network control system and the provincial control system; The operation boundary data of the second provincial power grid is obtained, and the initial conditions for power flow calculation are obtained by combining the first power grid state estimation data and the external network model.

4. The method for estimating power grid state based on power flow calculation according to claim 3, characterized in that: The initial conditions for the power flow calculation are obtained as follows: According to the maintenance plan data, the commissioning and decommissioning equipment of the power grid equipment in the future period is obtained; Find the commissioning and decommissioning equipment of the power grid equipment in the future period in the external network model, and perform disconnection processing in the planned period to obtain the first initial condition; Based on the first power grid state estimation data, using the first initial condition to calculate the measurement data of the historical planning period corresponding to the planning period, superimposing the measurement data of the historical planning period into the external network model to obtain the future form of the external network model; Based on the provincial dispatching unit power generation plan data, the provincial dispatching bus load forecast data, the tie line port sub-plan data and the system load forecast data, the first initial condition is used to calculate the measurement data of the historical planning period, and the measurement data of the historical planning period is superimposed on the model of the equipment in the network dispatching power grid to obtain the future form of the model of the equipment in the network dispatching power grid; The initial conditions for power flow calculation are generated according to the future form of the external network model and the future form of the model of the equipment in the network control power grid.

5. The method for estimating power grid state based on power flow calculation according to claim 4, characterized in that: The first power grid state estimation data derived from the network control system and the provincial control system are spliced ​​to construct an external network model, specifically: Determine the boundary equipment between the network dispatching power grid and the provincial dispatching power grid, and determine the plant station of the boundary equipment; Determining a boundary range according to a connection line between the boundary equipment and the plant station; Deleting equipment outside the boundary range in the provincial power grid; Deleting equipment within the boundary range in the network control grid; The external network model is generated based on the model parameters and measurement data of the devices that have not been deleted.

6. The method for estimating power grid state based on power flow calculation according to claim 5, characterized in that: The Cap_G power flow calculation module is combined to perform power flow calculation on the initial conditions of power flow calculation, specifically: Determine the node type of each node in the power grid, wherein the node type includes a PQ node, a PV node, and a balancing node; Based on the initial conditions of the power flow calculation, construct a power flow equation; The power flow equation is linearized in combination with the initial Jacobian matrix, and the final Jacobian matrix is ​​obtained after convergence through the Newton-Raphson method.

7. The method for estimating power grid state based on power flow calculation according to claim 6, characterized in that: The grid state sensitivity matrix is ​​defined as follows: Right now, Where: correspond , reflects the relationship between active power and real part of voltage; correspond , reflects the relationship between reactive power and real part of voltage; correspond , reflects the relationship between active power and imaginary part of voltage; correspond , reflects the relationship between reactive power and imaginary part of voltage, is the partial derivative of the active power of the i-th node with respect to the phase angle of the j-th node, is the partial derivative of the active power of the i-th node with respect to the voltage amplitude of the j-th node, is the partial derivative of the reactive power of the i-th node with respect to the phase angle of the j-th node, is the partial derivative of the reactive power of the i-th node with respect to the voltage amplitude of the j-th node, is the active power of the ith node, is the reactive power of the ith node, is the active power of the jth node, is the reactive power of the jth node, is the voltage amplitude of the ith node, is the voltage amplitude of the jth node, is the phase angle of the ith node, is the phase angle of the jth node.

8. A device using the power grid state estimation method based on power flow calculation as claimed in any one of claims 1 to 7, characterized in that: include: Data acquisition module, power flow calculation module, sensitivity matrix calculation module, optimization and fault analysis module: Data acquisition module: used to acquire and analyze the power grid system status data of the historical control system to obtain the initial conditions for power flow calculation, wherein the power grid system status data includes the first power grid status estimation data and the second provincial power grid operation boundary data; Power flow calculation module: used to combine Cap_G power flow calculation module to perform power flow calculation on initial conditions and obtain Jacobian matrix; Sensitivity matrix calculation module: used for performing matrix operation on the Jacobian matrix to obtain a power grid state sensitivity matrix; Optimization and fault analysis module: used for applying the power grid state sensitivity matrix to the optimization and fault analysis system of the power grid.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute a power grid state estimation method based on power flow calculation as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for estimating a power grid state based on power flow calculation as claimed in any one of claims 1 to 7 is implemented.

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