Power grid fluctuation detection method and device and electronic equipment

Abstract

The invention discloses a power grid fluctuation detection method and device and electronic equipment. The method comprises the following steps: generating a high-voltage power distribution network region model and a middle-low voltage power distribution network region model in a target region, and combining the high-voltage power distribution network region model and the middle-low voltage power distribution network region model into a power grid structure model of the target region; determining parameter indexes of each load node in the high-voltage power distribution network region model and the medium-low-voltage power distribution network region model respectively to obtain a parameter index set; acquiring electric power parameters of each load node in the power grid structure model to obtain a target electric power parameter set; performing load flow calculation on the power grid structure model by using the target power parameter set to obtain a calculation result; and determining the power grid fluctuation condition of the target area according to the calculation result and the parameter index set. Through the voltage fluctuation detection method and device, the problem that a traditional voltage fluctuation detection method is low in voltage fluctuation detection accuracy in the related technology is solved.

Description

Technical Field

[0001] The present application relates to the field of power systems, and more particularly, to a method and apparatus for detecting grid fluctuations, and an electronic device. Background Art

[0002] With the rise of new energy power generation, especially wind and photovoltaic power generation, due to the intermittency and uncertainty of their power output, it poses a major challenge to the stable operation of traditional power grids. The voltage regulation technologies of traditional power grids were mainly designed for fossil fuel power plants with stable operation and predictable power output. These technologies are inadequate in dealing with the random fluctuations of new energy power generation, especially in the case where distributed new energy power stations are widely connected to regional power grids.

[0003] Traditional methods for detecting voltage fluctuations, such as voltage monitoring based on fixed - interval periodic sampling and analyzing voltage data relying on a few key nodes, due to their inherent limitations, such as long sampling periods and uneven distribution of monitoring points, are difficult to capture the instantaneous dynamics and local details of voltage changes. Especially when the new energy output fluctuates greatly, these methods often cannot detect voltage over - limit situations in a timely and accurate manner, thus affecting the operation safety and power quality of the power grid.

[0004] Aiming at the problem that the traditional methods for detecting voltage fluctuations in related technologies have low detection accuracy for voltage fluctuations, no effective solution has been proposed yet. Summary of the Invention

[0005] The present application provides a method and apparatus for detecting grid fluctuations, and an electronic device, to solve the problem that the traditional methods for detecting voltage fluctuations in related technologies have low detection accuracy for voltage fluctuations.

[0006] According to one aspect of the present application, a method for detecting grid fluctuations is provided. The method includes: generating a high - voltage distribution network area model and a medium - and - low - voltage distribution network area model within a target area, and combining the high - voltage distribution network area model and the medium - and - low - voltage distribution network area model into a grid structure model of the target area, where the high - voltage distribution network area model is a model of a power grid area where the node voltage is greater than a preset voltage, and the medium - and - low - voltage distribution network area model is a model of a power grid area where the node voltage is less than or equal to the preset voltage; respectively determining the parameter indexes of each load node in the high - voltage distribution network area model and the medium - and - low - voltage distribution network area model to obtain a parameter index set; obtaining the electrical parameters of each load node in the grid structure model to obtain an initial electrical parameter set, and correcting the abnormal parameters in the initial electrical parameters to obtain a target electrical parameter set; performing a power flow calculation on the grid structure model using the target electrical parameter set to obtain a calculation result; and determining the grid fluctuation situation of the target area according to the calculation result and the parameter index set.

[0007] Optionally, generating a high-voltage distribution network regional model within a target area includes: obtaining an initial power grid model of the target area; deleting equipment models other than those of the first voltage level in the initial power grid model to obtain a first candidate power grid model; performing topological coloring analysis on the first candidate power grid model to obtain multiple first topological islands, where each first topological island includes multiple first load nodes electrically connected together; obtaining the initial power grid model of the target area, deleting equipment models other than those of the second voltage level in the initial power grid model to obtain a second candidate power grid model; performing topological coloring analysis on the second candidate power grid model to obtain multiple second topological islands; obtaining the initial power grid model of the target area, deleting equipment models other than those of the third voltage level in the initial power grid model to obtain a third candidate power grid model; performing topological coloring analysis on the third candidate power grid model to obtain multiple third topological islands; and combining the multiple first topological islands, multiple second topological islands, and multiple third topological islands into a high-voltage distribution network regional model.

[0008] Optionally, generating a medium- and low-voltage distribution network regional model within a target area includes: obtaining a transmission network model and a distribution network model within the target area; processing the transmission network model to establish a coordinated control area based on multiple target buses in the transmission network model; processing the distribution network model, deleting all disconnectors and circuit breakers in the open state in the distribution network model, and performing topological coloring analysis on the remaining distribution network model to obtain multiple fourth topological islands; dividing the target buses connected together in each fourth topological island into a distribution network area to obtain multiple control areas, and combining the multiple control areas and the transmission network model into a medium- and low-voltage distribution network regional model.

[0009] Optionally, obtaining the power parameters of each load node in the power grid structure model to obtain an initial power parameter set, and correcting the abnormal parameters in the initial power parameters to obtain a target power parameter set includes: determining whether each power parameter in the initial power parameter set meets the corresponding parameter requirements; obtaining the abnormal power parameters that do not meet the parameter requirements, and estimating the abnormal power parameters through an integrated state estimation algorithm to obtain a target power parameter set.

[0010] Optionally, estimating the abnormal power parameters through an integrated state estimation algorithm to obtain a target power parameter set includes: determining an initial estimation parameter based on the abnormal power parameters, performing a power flow calculation through the initial estimation parameter and the initial power parameter set, and iterating the initial estimation parameter according to the calculation result of the power flow calculation until the initial estimation parameter converges and then stopping the iteration, determining the initial estimation parameter corresponding to the stop of the iteration as the updated initial estimation parameter, and using the updated initial estimation parameter to replace the abnormal power parameters in the initial power parameter set to obtain a target power parameter set.

[0011] Optionally, determining the power grid fluctuation condition of the target area according to the calculation result and the parameter index set includes: obtaining the index values of each evaluation index in the calculation result from the parameter index set, and comparing the evaluation index to which each index value belongs with the corresponding evaluation criterion to obtain multiple comparison results; determining the power grid fluctuation condition according to the multiple comparison results.

[0012] Optionally, performing a power flow calculation on the power grid structure model using the target power parameter set, and the obtained calculation result includes: inputting each power parameter in the target power parameter set into the integrated power flow calculation algorithm to obtain the calculation result. Among them, the integrated power flow calculation algorithm decomposes the power grid structure model into a high-voltage main power grid model and a medium-low voltage secondary power grid model through the master-slave splitting method. The high-voltage main power grid model contains the parameters of high-voltage side equipment, and the medium-low voltage secondary power grid model contains the parameters of medium-low voltage side equipment. In the high-voltage main power grid model, perform a decomposed power flow calculation to obtain the power flow distribution of the high-voltage main power grid model. In the medium-low voltage secondary power grid model, based on the power flow distribution of the high-voltage main power grid model, perform a matching current state estimation and power flow calculation to determine the power flow distribution of the medium-low voltage secondary power grid model, and integrate the power flow calculation results of the high-voltage main power grid model and the medium-low voltage secondary power grid model to obtain the calculation result.

[0013] According to another aspect of the present application, a device for detecting power grid fluctuations is provided. The device includes: a first acquisition unit, configured to generate a high-voltage distribution network area model and a medium-low voltage distribution network area model in the target area, and combine the high-voltage distribution network area model and the medium-low voltage distribution network area model into a power grid structure model of the target area, where the high-voltage distribution network area model is a model of a power grid area where the node voltage is greater than the preset voltage, and the medium-low voltage distribution network area model is a model of a power grid area where the node voltage is less than or equal to the preset voltage; a first determination unit, configured to respectively determine the parameter indexes of each load node in the high-voltage distribution network area model and the medium-low voltage distribution network area model to obtain a parameter index set; a second acquisition unit, configured to acquire the power parameters of each load node in the power grid structure model to obtain an initial power parameter set, and correct the abnormal parameters in the initial power parameters to obtain a target power parameter set; a calculation unit, configured to perform a power flow calculation on the power grid structure model using the target power parameter set to obtain a calculation result; a second determination unit, configured to determine the power grid fluctuation condition of the target area according to the calculation result and the parameter index set.

[0014] According to another aspect of the present invention, a computer program product is further provided, including a computer program, and when the computer program is executed by a processor, it implements a method for detecting power grid fluctuations provided in the foregoing embodiments of the present application.

[0015] According to another aspect of the present invention, there is also provided an electronic device, comprising one or more processors and a memory; computer-readable instructions are stored in the memory, and the processor is configured to run the computer-readable instructions, wherein, when the computer-readable instructions are running, they execute a method for detecting power grid fluctuations provided in the foregoing embodiments.

[0016] Through the present application, the following steps are adopted: generating a high-voltage distribution network area model and a medium- and low-voltage distribution network area model in a target area, and combining the high-voltage distribution network area model and the medium- and low-voltage distribution network area model into a power grid structure model of the target area, wherein the high-voltage distribution network area model is a model of a power grid area where the node voltage is greater than a preset voltage, and the medium- and low-voltage distribution network area model is a model of a power grid area where the node voltage is less than or equal to the preset voltage; respectively determining the parameter indexes of each load node in the high-voltage distribution network area model and the medium- and low-voltage distribution network area model to obtain a set of parameter indexes; obtaining the power parameters of each load node in the power grid structure model to obtain an initial power parameter set, and correcting the abnormal parameters in the initial power parameters to obtain a target power parameter set; using the target power parameter set to perform a power flow calculation on the power grid structure model to obtain a calculation result; and determining the power grid fluctuation condition of the target area according to the calculation result and the set of parameter indexes. This solves the problem that the traditional voltage fluctuation detection method in the related art has a low detection accuracy for voltage fluctuations. By segmenting the power grid structure model, determining the set of parameter indexes of the high-voltage distribution network area model and the medium- and low-voltage distribution network area model, and through the state estimation calculation method of integrated main and distribution, correcting the initial power parameter set to obtain a target power parameter set, and then using the target power parameter set to perform the integrated main and distribution power flow calculation to obtain all the power parameters of each load node in the power grid structure model, and then determining the fluctuation condition of the power grid according to each power parameter and the corresponding parameter index, thus achieving the technical effect of accurately determining the power grid fluctuation condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0018] Figure 1 is a flowchart of a method for detecting power grid fluctuations provided in an embodiment of the present application;

[0019] Figure 2 is a schematic diagram of a radial distribution system provided in an embodiment of the present application;

[0020] Figure 3 is a schematic diagram of a master-slave splitting method based on distribution network equivalence provided in an embodiment of the present application;

[0021] Figure 4 It is a schematic diagram of a power grid fluctuation detection device provided according to an embodiment of the present application;

[0022] Figure 5 It is a schematic diagram of an electronic device provided according to an embodiment of the present application. Specific embodiments

[0023] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of the present application described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0026] It should be noted that the power grid fluctuation detection method, device and electronic device determined by the present disclosure can be used in the power system field, and can also be used in any field other than the power system field. The application field of the power grid fluctuation detection method, device and electronic device determined by the present disclosure is not limited.

[0027] It should be noted that the information collected, user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) used in this application are all information and data authorized by the user or fully authorized by all parties. Moreover, the collection, storage, use, processing, transmission, provision, disclosure, application and other processing of relevant data comply with relevant laws, regulations and standards in the relevant regions, adopt necessary confidentiality measures, do not violate public order and good customs, and provide corresponding operation entrances for users to choose to authorize the use or refuse to use. If the user chooses to refuse, the expert decision-making process will be entered. For example, there is an interface between this system and relevant users or institutions. Before obtaining relevant information, a request for acquisition needs to be sent to the aforementioned users or institutions through the interface, and relevant information can be obtained after receiving the consent information feedback from the aforementioned users or institutions.

[0028] The embodiments or examples of the present disclosure are not exhaustive. They are only schematic illustrations of some embodiments or examples and do not constitute specific limitations on the protection scope of the present disclosure. Without contradiction, each step in a certain embodiment or example can be implemented as an independent embodiment, and the steps can be combined arbitrarily. For example, the solution after removing some steps in a certain embodiment or example can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment or example can be arbitrarily exchanged. Additionally, the optional ways or optional examples in a certain embodiment or example can be combined arbitrarily; furthermore, the embodiments or examples can be combined arbitrarily. For example, some or all of the steps of different embodiments or examples can be combined arbitrarily, and a certain embodiment or example can be combined arbitrarily with the optional ways or optional examples of other embodiments or examples.

[0029] For the convenience of description, some nouns or terms related to the embodiments of this application are explained as follows:

[0030] Power flow calculation: It is a fundamental and key technology in power system analysis, used to determine the voltage magnitudes and phase angles of each node in the power system under given operating conditions, as well as the active and reactive power flows in the lines. Through power flow calculation, the health status of the power grid can be monitored, the stability and security of the power grid can be evaluated, and the operation of the power grid can be optimized.

[0031] Distribution network: It is an important link in the power system that connects power plants (or the main power grid) with end-users, responsible for converting high-voltage electricity into medium- and low-voltage electricity suitable for households and enterprises and distributing it to each user. The structure of the distribution network is usually relatively complex, including multiple voltage levels, such as 110 kV, 35 kV, 10 kV, and 380 V, etc., as well as various electrical equipment, such as transformers, switches, capacitors, reactors, and lines.

[0032] Main power grid: It is the core part of the power system, responsible for long-distance power transmission and large-capacity power exchange. It consists of high-voltage and extra-high-voltage (such as 500 kV, 750 kV) transmission lines and large substations. The role of the main power grid is to transmit the power generated by power plants (usually at high voltage) through transmission lines and substations to various regions, and then distribute it to end-users through the distribution network.

[0033] Figure 1 It is a flowchart of the method for detecting power grid fluctuations provided by the embodiments of the present application. As Figure 1 shown, the method includes the following steps:

[0034] Step S101, generate a high-voltage distribution network area model and a medium- and low-voltage distribution network area model in the target area, and combine the high-voltage distribution network area model and the medium- and low-voltage distribution network area model into a power grid structure model of the target area. Among them, the high-voltage distribution network area model is a model of the power grid area where the node voltage is greater than the preset voltage, and the medium- and low-voltage distribution network area model is a model of the power grid area where the node voltage is less than or equal to the preset voltage.

[0035] It should be noted that the target area refers to a specific electrical area for reactive power and voltage analysis. The power grid structure model includes the topological structure, parameter information, and operating status of all power grid equipment. The high-voltage distribution network area model is a power grid area model where the node voltage is greater than the preset voltage (such as 110 kV), and the medium- and low-voltage distribution network area model is a power grid area model where the node voltage is less than or equal to the preset voltage (such as 110 kV).

[0036] Specifically, when analyzing the power grid fluctuations in the target area, first, it is necessary to obtain the complete power grid model data from the system according to the voltage level of the power grid, and divide the power grid model into a high-voltage distribution network area model and a medium- and low-voltage distribution network area model according to the voltage level standard (such as taking 110 kV as the boundary). Finally, recombine these two area models to form a complete power grid structure model of the target area, thus ensuring the integrity of the analysis model and laying a foundation for subsequent reactive power and voltage characteristic analysis and power grid fluctuation situation assessment.

[0037] Step S102, respectively determine the parameter indicators of each load node in the high-voltage distribution network area model and the medium- and low-voltage distribution network area model to obtain a set of parameter indicators.

[0038] It should be noted that the parameter indicators are quantitative data describing the characteristics of load nodes, including but not limited to load power, power factor, load type, etc.

[0039] Specifically, after determining the high-voltage distribution network regional model and the medium- and low-voltage distribution network regional model, it is necessary to determine the parameter indicators for the load nodes in the high-voltage distribution network model (such as the loads served by 110 kV substations) and the load nodes in the medium- and low-voltage distribution network model (such as the loads served by 35 kV, 10 kV substations, and distributed power sources connected to the grid at 380 V), which may include the active and reactive power demands of the loads, the load types (constant impedance, constant power, constant current), the power factor of the loads, etc. The parameter indicator set provides the basic information of the load demand and is the basis for calculating the grid fluctuation conditions and adjusting the reactive power voltage control strategy.

[0040] Step S103: Obtain the electrical parameters of each load node in the grid structure model to obtain an initial electrical parameter set, and correct the abnormal parameters in the initial electrical parameters to obtain a target electrical parameter set.

[0041] It should be noted that the initial electrical parameter set is also the original data set based on real-time measurements and other non-real-time data, including node voltages, branch powers, reactive power compensation equipment status, etc. The abnormal parameters are also the measurement data or unreasonable parameters that exceed the normal operating range, such as voltage mutations, power measurement errors, etc. The target electrical parameter set is also the data set used for subsequent state estimation and power flow calculation after correcting the parameters in the initial set and filling in pseudo-measurements, ensuring the accuracy and completeness of the data.

[0042] Specifically, after obtaining the parameter indicators, it is also necessary to obtain the electrical parameter values of each load node in the grid. Real-time measurement data (such as voltage, current, and power measurements) can be obtained from the system. At the same time, due to insufficient measurement configuration in the distribution network, pseudo-measurement data (based on historical data or prediction data) can be used to make up for the missing information. By detecting and correcting abnormal measurement data, an accurate grid operation state data set, that is, the target electrical parameter set, is formed. These data will be used for state estimation and power flow calculation to ensure the reliability and practicality of the results.

[0043] Step S104: Use the target electrical parameter set to perform a power flow calculation on the grid structure model to obtain a calculation result.

[0044] It should be noted that the calculation result is also the grid operation state data obtained after the power flow calculation, which reflects the power flow situation in the grid.

[0045] Specifically, after obtaining the power parameters, the power flow calculation of the power grid structure model can be performed using the calibrated and optimized target power parameter set. Among them, a power transmission and distribution integrated power flow calculation method based on decomposition and coordination can be used to simulate and predict the power flow in the power grid, especially when considering the randomness and uneven distribution characteristics of new energy generation such as distributed photovoltaics on the load side. The calculation results provide key information on the node voltage distribution, branch power flow, and power grid operation status of the power grid, which is a prerequisite for evaluating the power grid fluctuation situation and formulating reactive power voltage control strategies.

[0046] Step S105, determine the power grid fluctuation situation of the target area according to the calculation results and the parameter index set.

[0047] Specifically, after obtaining the calculation results, the power grid fluctuation situation in the target area can be evaluated by combining the calculation results of the power flow calculation and the parameter index set, which may include detecting voltage over-limit (i.e., the degree of voltage deviation from the allowable range), analyzing the balance between reactive power sources and reactive power loads, and evaluating the voltage support ability and reactive power regulation ability of the power grid in the face of load fluctuations or changes in new energy output. By detecting and comprehensively evaluating the power grid fluctuation situation, a reasonable reactive power voltage control strategy can be formulated to ensure the safe and stable operation of the power grid while improving the economy and efficiency of the power grid operation.

[0048] The power grid fluctuation detection method provided by the embodiments of this application obtains the power grid structure model of the target area, and divides the power grid structure model according to the voltage levels of the power grid to obtain a high-voltage distribution network area model and a medium- and low-voltage distribution network area model. Among them, the high-voltage distribution network area model is the model of the power grid area where the node voltage is greater than the preset voltage, and the medium- and low-voltage distribution network area model is the model of the power grid area where the node voltage is less than or equal to the preset voltage; respectively determine the parameter indicators of each load node in the high-voltage distribution network area model and the medium- and low-voltage distribution network area model to obtain a parameter indicator set; obtain the power parameters of each load node in the power grid structure model to obtain an initial power parameter set, and correct the abnormal parameters in the initial power parameters to obtain a target power parameter set; use the target power parameter set to perform a power flow calculation on the power grid structure model to obtain a calculation result; determine the power grid fluctuation situation of the target area according to the calculation result and the parameter indicator set. This solves the problem that the traditional voltage fluctuation detection method in the related technology has a low detection accuracy for voltage fluctuations. By dividing the power grid structure model, determining the parameter indicator sets of the high-voltage distribution network area model and the medium- and low-voltage distribution network area model, and through the state estimation calculation method of integrated main and distribution, correcting the initial power parameter set to obtain a target power parameter set, and then using the target power parameter set to perform the integrated main and distribution power flow calculation to obtain all the power parameters of each load node in the power grid structure model, and then determining the fluctuation situation of the power grid according to each power parameter and the corresponding parameter indicator, thus achieving the technical effect of accurately determining the power grid fluctuation situation.

[0049] Optionally, in the power grid fluctuation detection method provided by the embodiments of this application, generating the high-voltage distribution network area model in the target area includes: obtaining the initial power grid model of the target area, and deleting the equipment models other than those of the first voltage level in the initial power grid model to obtain a first candidate power grid model; performing topological coloring analysis on the first candidate power grid model to obtain multiple first topological islands, where each first topological island includes multiple first load nodes that are electrically connected together; obtaining the initial power grid model of the target area, and deleting the equipment models other than those of the second voltage level in the initial power grid model to obtain a second candidate power grid model; performing topological coloring analysis on the second candidate power grid model to obtain multiple second topological islands; obtaining the initial power grid model of the target area, and deleting the equipment models other than those of the third voltage level in the initial power grid model to obtain a third candidate power grid model; performing topological coloring analysis on the third candidate power grid model to obtain multiple third topological islands; combining the multiple first topological islands, the multiple second topological islands, and the multiple third topological islands into a high-voltage distribution network area model.

[0050] It should be noted that the target area refers to a specific geographical or electrical area for reactive voltage assessment. The first voltage level, the second voltage level, and the third voltage level respectively refer to the 220 kV, 110 kV, and 35 kV voltage levels, which are used to divide grid models at different levels. The equipment models include models of transformers, lines, capacitors, reactors, generators, etc. in the power grid. Topological coloring analysis is a systematic analysis method that can identify electrically connected equipment in the power grid and form topological islands for hierarchical analysis and control. The first load node refers to the load node at the first voltage level (such as 220 kV).

[0051] Specifically, obtaining the initial grid model means reading the complete grid model data of the target area from the system or database, including equipment models and topological structures at all voltage levels. In the case of obtaining the initial grid model, it is necessary to delete equipment models other than those at the 110 kV voltage level, including: deleting all line models other than those at the 110 kV voltage level; deleting all switch-disconnector models other than those at the 110 kV voltage level; deleting all switch-disconnector models in the 110 kV voltage level that are in the off state, to obtain the first candidate grid model, which mainly consists of equipment models at low voltage levels (110 kV, 35 kV, and 10 kV).

[0052] Furthermore, it is necessary to perform topological analysis on the first candidate grid model, and calibrate electrically connected equipment with the same color through the closing state of the bus coupler switch to form multiple first topological islands, and each island represents an independent operating area where 110 kV and 35 kV equipment are connected through 220 kV main transformers.

[0053] Next, it is necessary to read the complete grid model data of the target area from the system or database, and delete equipment models other than those at the 35 kV voltage level to obtain the second candidate grid model. For example, delete all line models other than those at the 35 kV voltage level; delete all switch-disconnector models other than those at the 35 kV voltage level; delete all switch-disconnector models in the 35 kV voltage level that are in the off state. Furthermore, perform topological coloring analysis on the second candidate grid model in the same way to identify multiple second topological islands, and each island consists of an area where 35 kV equipment is connected through 110 kV main transformers.

[0054] Next, it is necessary to read the complete grid model data of the target area from the system or database, and delete equipment models other than those at the 35 kV voltage level to obtain the third candidate grid model. For example, delete all line models other than those at the 35 kV voltage level; delete all switch-disconnector models other than those at the 35 kV voltage level; delete all switch-disconnector models in the 35 kV voltage level that are in the off state, and perform topological coloring analysis in the same way to form multiple third topological islands, and each island represents an area where 10 kV equipment is connected through 35 kV main transformers.

[0055] Finally, combine the first topological island, the second topological island, and the third topological island to form a high-voltage distribution network regional model for the target area. This model contains power grid structure information from 220 kV to 10 kV.

[0056] Through the above steps, a high-voltage distribution network regional model within the target area can be automatically generated. This model can accurately reflect the power grid structure and load distribution at each voltage level, providing a solid foundation for the evaluation and control of reactive power and voltage. Based on 220 kV, 110 kV, and 35 kV as benchmarks, perform topological analysis step by step to divide the power grid into multiple independent control areas, facilitating the implementation of hierarchical and zonal reactive power and voltage evaluation and optimization control strategies. This process not only improves the intelligent level of power grid management but also enhances the analysis accuracy of power grid voltage fluctuations, ensuring the stability and economy of power grid operation.

[0057] For example, the following is an optional generation process for the regional model of a high-voltage distribution network. It should be noted that the currently mainly operating voltage levels of the power grid are 500 kV (750 kV), 220 kV (330 kV), 110 kV (110 kV), 35 kV, and 10 kV. The operating modes between power grids at each voltage level are as follows:

[0058] 1. The 500 kV (750 kV) power grid adopts the operation mode of regional power grid loop closing, that is, all 500 kV substations in the large regional power grid (such as the North China Power Grid) are connected together to form an electrical island for operation.

[0059] 2. The 220 kV (330 kV) power grid adopts the operation mode of partial loop closing, that is, some 220 kV (330 kV) substations are connected together and supplied by several upper-level 500 (750) kV substations, forming a many-to-many power supply relationship. Multiple upper-level 500 (750) kV power supply substations supply power to multiple lower-level load 220 kV (330 kV) substations. Such an area is generally called a supply area. The number of upper-level power supply substations in the supply area may generally range from 1 to more than a dozen, and the number of lower-level load 220 kV (330 kV) substations may generally range from several to dozens.

[0060] 3. Power grids with a voltage level of 110 kV and below adopt a radial operation mode, that is, some 110 kV (110 kV) substations are connected together and supplied by 1 upper-level 220 kV (330 kV) substation. It may be supplied by multiple main transformers operating in parallel in the upper-level substation or by some main transformers in the upper-level substation. Overall, a one-to-many power supply relationship is formed. 1 upper-level 220 (330) kV power supply substation supplies power to multiple lower-level load 110 kV (110 kV) substations. This power supply relationship is also called a radial supply area.

[0061] Therefore, to analyze the reactive power and voltage operation of 500 kV to 10 kV busbars across the entire network, it is necessary to analyze the reactive power flow between the upper and lower levels within the closed-loop area of 500 kV - 220 kV, the reactive power exchange between regions, and to analyze the multi-level radiation regional power grid of 220 kV - 110 kV - 35 kV; analyze the reactive power flow between different voltage levels within the region, including:

[0062] 1) Automatic generation technology for reactive power and voltage regions at all voltage levels across the entire network;

[0063] 2) Analysis of the reactive power and voltage operation characteristics and reactive power and voltage indicators of each regional power grid.

[0064] When generating the 220 kV - 110 kV - 35 kV regional model of the high-voltage distribution network on the load side, it can be generated through the following process:

[0065] (I) Definition of the regional model

[0066] In the above regional power grid model, the complete area of the subordinate 110 kV and 35 kV substations starting from the 220 kV busbar is defined as the regional power grid coordinated control area. Without loss of generality, the coordinated control area is expressed in the following form.

[0067]

[0068] Among them:

[0069] There are a total of N 220 kV main transformers.

[0070] There are a total of H 220 kV busbars connected to the high-voltage windings of the 220 kV main transformers (busbars operating in parallel through closed bus-tie switches are combined into one, the same below).

[0071] There are a total of M 110 kV busbars connected to the medium-voltage windings of the 220 kV main transformers.

[0072] There are a total of L 35 kV busbars connected to the low-voltage windings of the 220 kV main transformers.

[0073] There are a total of J high-voltage busbars of the subordinate 110 kV substations connected, J ≥ M.

[0074] There are a total of P high-voltage busbars of the subordinate 35 kV substations connected, P ≥ L.

[0075] Each 110kV substation high voltage side bus The 110-35kV sub-area is May bring one or more That is, K≥J.

[0076] Each sub-region Further defined as:

[0077]

[0078] in:

[0079] 110kV main transformers, totaling N′ units.

[0080] There are H′ 110kV busbars in total connected to the high-voltage side winding of the 110kV main transformer.

[0081] There are M′ 35kV busbars in total connected to the medium voltage side winding of the 110kV main transformer.

[0082] The total number of high-voltage side busbars of the connected downstream 35kV substation is P′, and J′≥M′.

[0083] It should be noted that since the buses running in parallel through the closed bus tie switch have been merged into one, the following conditions should be met:

[0084] H≤N,M≤N,L≤N

[0085] H′≤N′, M′≤N′, L′≤N′

[0086] In regional power grids, since power grids below 220kV mostly adopt radial operation, multiple transformers may be operated in parallel or separately inside 220kV substations and 110kV substations; the closed-loop operation mode is not adopted between 110kV substations and 35kV substations. In this case, the following conditions should be met:

[0087] H=1,M≥H,L≥H,K≥H

[0088] H′=1, M′≥H′, L′≥H′, K′≥H′

[0089] Since the operation mode of the regional power grid often changes, it is necessary to automatically generate the regional power grid coordinated control partition in real time in the regional power grid automatic voltage control. It is necessary to study the method of automatically generating coordinated control zones. It mainly consists of two parts: the part connected to the 220 kV main transformer: and the lower-level 35 kV sub-region part connected to the 110 kV main transformer in the 110 kV substation: Therefore, the process of automatically generating the coordinated control area is also divided into two steps, which respectively complete the topological analysis of the network powered by the 220 kV main transformer and the topological analysis of the network powered by the 110 kV main transformer. Through multi-level topological analysis, the coordinated control area of the entire regional power grid is automatically generated.

[0090] (2) Regional automatic generation algorithm

[0091] 1) First, conduct a topological analysis of the network powered by the 220 kV main transformer in the power grid:

[0092] For the topological analysis of the network powered by the 220 kV main transformer, first generate the model of the 110 kV power grid connected to the 220 kV main transformer and generate the coordinated control area Z 220 , and the process is as follows:

[0093] Step 1: Obtain the complete power grid model from the regional power grid system;

[0094] Step 2: Process the complete power grid model, delete all line models outside the 110 kV voltage level; delete all switch-disconnector models outside the 110 kV voltage level; delete all switch-disconnector models in the off state within the 110 kV voltage level;

[0095] Step 3: Conduct topological coloring analysis on the remaining power grid model to form several topological islands, and each topological island includes several power grid devices that are electrically connected together.

[0096] Step 4: Check all topological islands in turn. If a topological island i contains a 220 kV transformer and a 110 kV substation, then establish a coordinated control area corresponding to this topological island i

[0097] Step 5: Process the 220 kV transformer on the topological island i, and add the 220 kV transformer Add Add the bus connected to the high-voltage side winding of the 220 kV transformer (buses connected in parallel through closed bus coupler switches are merged into one, the same below) Add Add the medium-voltage side bus of the 220 kV transformer Add Add the low-voltage side bus of the 220 kV transformer Add

[0098] Step 6: Process the 110 kV substation on the topological island i, and add the high-voltage side busbar of the 110 kV substation to

[0099] After completing the above steps, at this time

[0100] Furthermore, continue to add the 35 kV substation connected to the low-voltage side of the 220 kV transformer to as follows:

[0101] Step 1: Obtain a complete power grid model from the regional power grid system;

[0102] Step 2: Process the complete power grid model, delete all line models except those of the 35 kV voltage level; delete all switch-disconnector models except those of the 35 kV voltage level; delete all switch-disconnector models in the 35 kV voltage level that are in the open state;

[0103] Step 3: Conduct topological coloring analysis on the remaining power grid model to form several topological islands, each of which includes several power grid devices that are electrically connected together.

[0104] Step 4: Check all topological islands in turn. If a topological island contains a 220 kV transformer and a 35 kV substation, mark this transformer as Check all the generated coordinated control areas. If a certain coordinated control area is satisfied:

[0105]

[0106] then add the high-voltage side busbar of the 35 kV substation to as well.

[0107] In the regional power grid, the 35 kV busbars on the low-voltage side of the 220 kV main transformers generally operate in a split mode, that is, there is a situation where L = N. Therefore, in the above steps, only the unique satisfies the formula.

[0108] After completing the above steps, at this time

[0109] Furthermore, it is necessary to analyze the network powered by the 110 kV main transformer:

[0110] 2) Topological analysis of the network powered by the 110 kV main transformer in the power grid:

[0111] Generate a model of the 35 kV power grid connected to the 110 kV main transformer and generate a coordinated sub-control area z 110 , the process is as follows:

[0112] Step 1: Obtain a complete power grid model from the regional power grid system;

[0113] Step 2: Process the complete power grid model, delete all line models except those at the 35 kV voltage level; delete all switch disconnector models except those at the 35 kV voltage level; delete all switch disconnector models in the 35 kV voltage level that are in the open state;

[0114] Step 3: Conduct topological coloring analysis on the remaining power grid model to form several topological islands, each of which includes several power grid devices electrically connected together.

[0115] Step 4: Check all topological islands in sequence. If a certain topological island k contains a 110 kV transformer and a 35 kV substation, then establish a coordinated control area corresponding to this topological island k

[0116] Step 5: Process the 110 kV transformer on topological island k, add the 110 kV transformer join Add the bus connected to the high-voltage side winding of the 110 kV transformer join Add the medium-voltage side bus of the 110 kV transformer join

[0117] Step 6: Process the 35 kV substation on topological island k, add the high-voltage side bus of the 35 kV substation join

[0118] After the above steps are completed, for each A complete sub-region model has been obtained.

[0119] 3) Add the 110 kV sub-region to the coordinated control area:

[0120] Check all the generated ones in sequence For in If a certain in Satisfies the following formula:

[0121]

[0122] That is, if the above three conditions are simultaneously satisfied, then add to in.

[0123] Through the above three steps, a complete reactive power voltage coordinated control area model of the high-voltage distribution network on the load side is finally formed:

[0124] Optionally, in the power grid fluctuation detection method provided in the embodiments of the present application, generating a medium- and low-voltage distribution network area model in a target area includes: obtaining an initial power grid model of the target area; processing the transmission network model, and establishing a coordinated control area according to multiple target buses in the transmission network model; processing the distribution network model, deleting all disconnector switches and circuit breakers in the distribution network model in the off state, and performing topological coloring analysis on the remaining distribution network model to obtain multiple fourth topological islands; dividing the target buses connected together in each fourth topological island into a distribution network area to obtain multiple control areas, and combining the multiple control areas and the transmission network model into a medium- and low-voltage distribution network area model.

[0125] It should be noted that the target area refers to a specific electrical area for reactive power voltage assessment, such as the distribution network system of a city. The coordinated control area is a control area based on specific buses or power grid nodes, aiming to optimize the reactive power voltage control within this area. The fourth topological island is also a set of multiple power grid devices that are electrically connected together obtained through topological coloring analysis, representing an independent area in the 10kV power grid.

[0126] Specifically, when generating the medium- and low-voltage distribution network area model, it is first necessary to read the complete power grid model in the target area from the system, and for the transmission network model in the power grid model, establish a coordinated control area according to multiple target buses (such as 10kV buses) therein, so as to identify the control area centered on the 10kV bus, facilitating subsequent reactive power voltage control and assessment.

[0127] Furthermore, it is also necessary to process the distribution network model, remove all disconnector switches and circuit breakers in the separated or disconnected state to ensure that the model only contains the devices that are electrically connected during actual operation, and perform topological coloring analysis on the remaining distribution network model, calibrating the 10kV devices that are electrically connected together with the same color to form multiple fourth topological islands, and each island represents an independent area composed of 10kV lines, capacitors, voltage regulators, new energy power stations, and distribution transformers.

[0128] Finally, divide the target buses connected together in each fourth topological island into a distribution network area to form multiple distribution network coordinated control areas, and then combine these control areas with the previous transmission network model to construct a medium- and low-voltage distribution network area model covering the target area.

[0129] For example, assume that the target area is the distribution network of a certain urban area, including devices of different voltage levels of 110kV, 35kV, and 10kV.

[0130] First, obtain the distribution network model of the entire area from the system, including equipment below the 10kV bus. Then, delete all 10kV disconnectors and circuit breakers in the open state to ensure that all electrical equipment in the distribution network model is connected. Next, perform topological coloring analysis on the processed distribution network model to identify multiple fourth topological islands composed of 10kV equipment and electrically connected to each other. Divide the equipment (such as feeders, capacitors, voltage regulators, new energy power stations, and distribution transformers) connected to the same 10kV bus in each fourth topological island into a distribution network area D to form multiple distribution network coordinated control areas Z:10. Finally, combine these Z:10 areas with the coordinated control area Z:110 at the 110kV level that has been processed to form the medium and low voltage distribution network area model of the target area.

[0131] Through the above steps, the medium and low voltage distribution network area model within the target area can be automatically and intelligently generated, including the distribution network structure accurate to the 10kV level and the related control areas. The generation of this model not only depends on topological analysis but also verifies the operating status of power grid equipment (such as removing disconnected switches), ensuring the accuracy and effectiveness of the model. In addition, by integrating the medium and low voltage distribution network area model with the transmission network model, a model covering the entire distribution network from high voltage to low voltage is formed, facilitating the grid operator to conduct hierarchical and zonal evaluation and optimal control of the reactive power and voltage of the entire area, improving the stability and economy of grid operation, especially when dealing with voltage fluctuation problems caused by large-scale access of distributed new energy on the load side.

[0132] For example, the following is an optional generation process of the medium and low voltage distribution network area model. It should be noted that the distribution network control objects include 10kV capacitors and voltage regulators carried by 10kV distribution network lines; new energy power stations and small hydropower stations connected to 10kV; as well as capacitors on the low voltage side of distribution transformers and distributed power sources (such as rooftop photovoltaic and energy storage batteries) connected to the 380V grid on the low voltage side of distribution transformers. Among them, 10kV capacitors and voltage regulators can be directly controlled by issuing remote control and remote adjustment commands through the distribution network automation system. The new energy power stations connected to 10kV are controlled by issuing the voltage and reactive power at the grid connection point to the AVC substation (Automatic Voltage Control Substation). Capacitors on the low voltage side of distribution transformers and distributed power sources connected to the 380V grid on the low voltage side of distribution transformers are controlled through the AVC substation deployed at the distribution transformer. In the operation of the distribution network, radial operation is mostly adopted, that is, one or several 10kV lines of 110kV and 35kV substations bring out several 10kV distribution network feeders and distribution transformers, and open-loop operation is adopted between different 10kV outgoing lines (groups) without direct electrical connection.

[0133] Therefore, analyze the reactive power and voltage operation conditions of the distribution network, including:

[0134] 1) Automatic generation technology for distribution network coordination control areas;

[0135] 2) Analysis of reactive power voltage operation characteristics and reactive power voltage indexes in distribution network coordination control areas.

[0136] When generating the regional model of the medium and low voltage distribution network, it can be generated through the following process:

[0137] (I) Definition of regional model

[0138] In the power grid model, starting from the 10kV bus, the area served by the 10kV outgoing line (group) forms the basic calculation and control unit of the distribution network AVC - the distribution network coordination control area. Without loss of generality, the coordination control area is expressed in the following form.

[0139]

[0140] Where:

[0141] 10kV bus, one or multiple parallel operating buses, that is, the power source root nodes of the area, belonging to 110kV or 35kV substations, with a total of N;

[0142] 10kV feeder area, one or multiple loop - operating lines whose connected equipment constitutes the feeder area, with a total of O;

[0143] Among them, the 10kV feeder area is defined as:

[0144]

[0145] Where, 10kV outgoing line, one or multiple loop - operating lines, that is, the lines connected to the 10kV bus, which belong to a certain 10kV bus, with a total of M;

[0146] 10kV line segment, multiple 10kV distribution network feeder line segments connected from the 10kV outgoing line, whose start and end are connected to the upper - level 10kV line or other line segments, with a total of H;

[0147] 10kV capacitor, reactive power compensation capacitor connected to the 10kV line segment, whose endpoints are connected to a certain 10kV line segment node, with a total of J;

[0148] 10kV voltage regulator, voltage regulator connected to the 10kV line segment, whose start and end are connected to the 10kV line segment node, with a total of K;

[0149] 10 kV grid-connected new energy power stations, new energy stations connected to the grid through 10 kV, act as an adjustable equivalent generator in the distribution network, and their endpoints are connected to a certain 10 kV line node, with a total of P stations;

[0150] 10 kV distribution transformers, distribution transformers connected to the 10 kV line, whose high-voltage side windings are connected to a certain 10 kV line node, and the low-voltage side is connected to loads or distributed adjustable reactive power resources, with a total of Q units;

[0151] There is a hierarchical relationship between various objects in the area. At the same time, through the 10 kV bus in the area, the upper-level area of the distribution network coordinated control area can be found, that is, the 220 - 110 - 35 kV area formed in the master station. The distribution network coordinated control area can be automatically generated online through the power grid model and real-time operation data provided by the distribution network automation system. When the operation mode changes, it can be adaptively reconfigured.

[0152] (2) Regional automatic generation algorithm

[0153] Topological analysis of the distribution network coordinated control area is as follows:

[0154] Step 1: Obtain the complete transmission network model and distribution network model from the power grid system;

[0155] Step 2: Process the complete transmission network model, merge the 10 kV buses (buses operating in parallel through closed bus-tie switches into one), and establish a coordinated control area based on this bus

[0156] Step 3: Process the complete distribution network model, and delete the disconnector switches and circuit breakers in the off state;

[0157] Step 4: Conduct topological coloring analysis on the remaining distribution network model to form several topological islands, and each topological island includes several power grid devices that are electrically connected together.

[0158] Finally, check all topological islands in turn. For one or multiple 10 kV outgoing lines in the topological island that are connected to the same 10 kV bus (buses operating in parallel through closed bus-tie switches are merged into one) or are in a loop operation, form a feeder area with the feeder where the one or multiple 10 kV outgoing lines are located And add it to the coordinated control area corresponding to the connected 10 kV bus as Add the 10 kV outgoing lines, 10 kV lines, 10 kV capacitors, 10 kV voltage regulators, 10 kV grid-connected new energy power stations, and 10 kV distribution transformers connected to one or multiple 10 kV outgoing lines in the topological island to the feeder area Thus, a regional model of the medium and low voltage distribution network is obtained.

[0159] Optionally, in the power grid fluctuation detection method provided in the embodiments of the present application, obtaining the power parameters of each load node in the power grid structure model, obtaining an initial power parameter set, and correcting the abnormal parameters in the initial power parameters to obtain a target power parameter set includes: determining whether each power parameter in the initial power parameter set meets the corresponding parameter requirements; obtaining the abnormal power parameters that do not meet the parameter requirements, and estimating the abnormal power parameters through an integrated state estimation algorithm to obtain a target power parameter set.

[0160] It should be noted that the power grid structure model refers to the models of the load-side high-voltage distribution network (220kV - 110kV - 35kV region model) and the medium and low voltage distribution network (10kV and below) that have been obtained through the regional automatic generation algorithm. A load node refers to a point in the power grid that consumes electrical energy, including industrial and residential loads, as well as distributed power sources connected to the power grid. Power parameters include node voltage, branch power, load active and reactive power, the input status of capacitors and reactors, etc. The initial power parameter set is also the power grid operation state parameter set obtained based on real-time measurement and pseudo-measurement data, and may contain outliers. Abnormal parameters refer to power parameters that exceed the normal operating range, such as voltage mutations, power measurement errors, etc. The integrated state estimation algorithm is a calculation method based on robust technology to estimate the state of the power grid to provide more accurate parameter values and is applicable to the integrated environment of the transmission and distribution network.

[0161] Specifically, since there may be outliers in the obtained initial power parameters, it is necessary to obtain the real-time and pseudo-measurement data of each load node from the power grid structure model to form an initial power parameter set. By setting the normal operating range and data quality standards, each power parameter in the set is checked to identify outliers that exceed the normal range.

[0162] In the case where outliers are determined, the integrated state estimation algorithm can be applied to correct based on historical data, the power grid model, and other reliable parameters, and estimate parameter values that are closer to the actual operating state, thereby improving the accuracy of the power parameters and providing reliable data for subsequent reactive power voltage evaluation and control strategy formulation.

[0163] For example, taking a certain regional power grid as an example, this power grid includes a high-voltage distribution network (220kV - 110kV - 35kV) and a medium and low voltage distribution network (10kV and below).

[0164] First, a power grid structure model of the target area is generated, including a hierarchical and zonal model of the high-voltage distribution network on the load side and a hierarchical and zonal model of the medium- and low-voltage distribution network. Real-time measurement data and pseudo-measurement data are collected from the system, including the voltage, power, etc. of the load nodes, to form an initial set. The voltage and power data in the set are checked. For example, it is found that the voltage measurement value of a certain 10 kV node suddenly jumps and exceeds the normal operating range. An integrated state estimation algorithm is applied, combining the power grid model and historical data, to re-estimate the voltage of this 10 kV node, obtaining a more reasonable target voltage value, thereby correcting the abnormal parameters. After correction, a more accurate set of power parameters is obtained, including the corrected values of all load nodes, which is used for subsequent reactive power voltage evaluation and optimal control.

[0165] Through the above steps, abnormal power parameters of load nodes in the power grid structure model can be effectively identified and corrected, ensuring the accuracy and reliability of the data set used for reactive power voltage evaluation and control strategy formulation. The introduction of the integrated state estimation algorithm, especially the use of robust techniques, improves the robustness and accuracy of parameter estimation, and can adapt to the uncertainty and incompleteness of measurement data in the power grid, which is crucial for the operation analysis, control optimization, and accurate evaluation of voltage fluctuation levels of the high-voltage distribution network and medium- and low-voltage distribution network on the load side. By eliminating the interference of abnormal parameters, state analysis can be carried out based on a more realistic data set to formulate a more scientific reactive power voltage control strategy, ensuring the safe, high-quality, and economical power supply of the power grid. Especially when dealing with the challenges brought by load fluctuations and distributed new energy generation, more accurate decisions can be made.

[0166] Optionally, in the power grid fluctuation detection method provided in the embodiment of the present application, the abnormal power parameters are estimated by an integrated state estimation algorithm, and the obtained target power parameter set includes: determining initial estimation parameters according to the abnormal power parameters, performing power flow calculation through the initial estimation parameters and the initial power parameter set, and determining the initial estimation parameters corresponding to the stop of iteration as the updated initial estimation parameters, and using the updated initial estimation parameters to replace the abnormal power parameters in the initial power parameter set to obtain the target power parameter set.

[0167] It should be noted that high-voltage estimation parameters: state estimation parameters corresponding to the high-voltage distribution network (such as 220 kV and 110 kV levels), including node voltage, branch power, etc. Medium- and low-voltage estimation parameters: state estimation parameters corresponding to the medium- and low-voltage distribution network (such as 35 kV, 10 kV levels), also including node voltage, branch power, etc.

[0168] Specifically, when estimating abnormal power parameters, it is first necessary to identify outliers from the initial power parameter set, such as excessive voltage measurement value fluctuations, unreasonable power measurement data, etc. Then, set the initial estimation parameters, including the preliminary estimated values of abnormal parameters and other normal parameter values, to provide a starting point for state estimation.

[0169] When performing the estimation, the matching current state estimation algorithm can be used to perform power flow calculations based on the current initial estimation parameters and the initial power parameter set (including real-time measurement and pseudo-measurement data). By adjusting the initial estimation parameters according to the difference (residual) between the calculation result and the measurement value, the residual can be reduced and the accuracy of state estimation can be improved.

[0170] Furthermore, a convergence judgment criterion needs to be set. After each iteration, check whether the residual meets the convergence criterion. If not, continue to adjust the initial estimation parameters and perform the next round of calculations. When the residual reaches the set threshold (or changes very little), it indicates that the state estimation parameters have tended to be stable, and at this time, the iteration is stopped.

[0171] After the state estimation parameters converge and the iteration stops, the finally determined parameters are the corrected abnormal parameters. This includes key grid operation parameters such as the corrected voltage value and branch power. Then, use the corrected abnormal parameters to replace the abnormal power parameters in the initial power parameter set to obtain the target power parameter set, and then use the target power parameter set to perform subsequent reactive power voltage evaluation and control strategy formulation operations.

[0172] Through the precise iteration of the integrated state estimation algorithm in this embodiment, the effective correction of abnormal power parameters is achieved, and finally the accurate state estimation parameters of the high-voltage and medium-low-voltage grids are determined. This technical path not only overcomes the challenges of incomplete data and outliers, but also improves the accuracy of state estimation, which is of great significance for the refined management of the load-side grid, reactive power voltage optimization control, and coping with the voltage fluctuation problems brought by large-scale distributed new energy access. Through stable and accurate state estimation, grid operators can make more scientific and timely decisions, improving the safety and economy of grid operation.

[0173] For example, the following is an estimation process for optional state parameters. It should be noted that the integrated transmission and distribution network state estimation method can be executed through the integrated transmission and distribution network advanced analysis software. Building a smart distribution network first requires real-time perception of the operating state. State estimation is to calculate a consistent and reliable state of the main and distribution networks through limited measurements. Currently, the measurement configuration of the distribution network is still very poor. Except for the voltage, active and reactive power measurements at the root node within the autonomous substation, there are only real-time current measurements at some pole-mounted switches and branch lines, and there are quasi-real-time partial load measurements collected through the electricity billing system in the distribution substation area. Therefore, the existing distribution network state estimation algorithms are difficult to be actually applied in the distribution network field.

[0174] Aiming at the problems of low redundancy of real-time measurements and only partial current measurements in the distribution system, this embodiment proposes a state estimation technology of matching current to solve the state estimation. The matching current equation under the meaning of optimal estimation and its systematic solution method are deduced. The matching current technology is applicable to the situation with real-time current measurements and conforms to the current situation of the distribution network.

[0175] Specifically, first consider a typical distribution measurement configuration system. Figure 2 is a schematic diagram of a radial distribution system provided according to an embodiment of the present application, as Figure 2 shown. There can be N load nodes in this system, and the r node is the root node.

[0176] The root node has three-phase current and three-phase voltage amplitude measurements There are real-time power measurements at some important load nodes. N M load nodes have real-time three-phase active power measurements and real-time three-phase reactive power measurements Among them, C M is the set of nodes with real-time active and reactive power measurements.

[0177] The metering system collects three-phase load power measurements of the substation area every about 15 minutes. Due to the problem of time synchronization, these measurements do not match the real-time measurements and can only be used as pseudo-measurements, denoted as: active pseudo-measurement and reactive pseudo-measurement Among them, C - C M is the set of nodes configured with pseudo-measurements.

[0178] The above measurement configuration is a very typical situation under the current low level of distribution network automation. The real-time measurements are not sufficient to ensure the observability of the system. Even with the addition of load pseudo-measurements, the redundancy is very low. For this reason, in this embodiment, it is assumed that the real-time measurements are accurate and error-free. It can be assumed that the power factor of the load remains almost unchanged within a 15-minute time interval. Therefore, the ratio of the active power to the reactive power of the load The accuracy is matched with that of real-time measurement. Therefore, in state estimation, λ can also be considered to be accurate and error-free, which is equivalent to adding a real-time measurement to the system.

[0179] To adapt to the problem of three-phase imbalance in the distribution network, the methods of this embodiment all adopt a three-phase model. However, for the sake of simplified expression, the following formulas all adopt a single-phase model.

[0180] When performing estimation, the main distribution network state estimation problem can be converted into a calculation problem of matching power flow, and its matching power flow equation is:

[0181]

[0182] In the formula, i ∈ C M is N M the numbers of N load nodes with real-time active and reactive power measurements; PL k and QL k the total sum of the branch power flows flowing out of node k; P loss (V, θ), Q loss (V, θ) are the total active and reactive power network losses of the distribution network; △P ∑ , △Q ∑ are the boundary power mismatch amounts, and α and β are the boundary power mismatch amount distribution coefficients, simply referred to as distribution coefficients Given a set of α and β, a unique power flow distribution can be obtained. For the three-phase model, the 6N + 6 unknowns in the matching power flow equation include V, θ, △P ∑ , △Q ∑ , and the number of equations is 6N + 6, which satisfies the definite solution conditions of the equations.

[0183] However, for the measurement configuration proposed in this embodiment, the matching power flow equation is no longer applicable. For this reason, the matching current equation proposed in this embodiment is:

[0184]

[0185] where δ is the phase angle difference between the root node current and voltage, and are respectively the real-time measurements of the root node current and voltage, α is the boundary power mismatch amount distribution coefficient,

[0186] The matching current equation proposed in this embodiment has 6N + 6 unknowns including V, θ, ΔP ∑ , δ. The number of equations is 6N + 6, which satisfies the definite solution conditions of the equations. Given a set of α, a unique power flow distribution can be obtained.

[0187] It should be noted that in the case where the power flow distribution is calculated by the matching current equation proposed in this embodiment, the optimal matching current can also be selected from multiple power flow calculation results. Among them, the optimal matching current is essentially optimized in the space. If the residual vector is taken as the state quantity of the optimal estimate, the optimal estimate is:

[0188]

[0189] S.t.

[0190]

[0191] In the formula, is the weight coefficient of the active power pseudo-measurement of the given k-node load.

[0192] According to the KKT condition, if the network loss P loss and Q loss are ignored for derivatives (mainly considering that after being divided into multiple small measurement areas according to current measurements, has little impact on network loss and δ), and then we get:

[0193]

[0194] Among them,

[0195]

[0196] From the perspective of the optimal estimate, given the weight of the pseudo-measurement, the distribution coefficient of the boundary mismatch active power can be calculated using the above formula, so as to calculate a definite power flow solution.

[0197] Furthermore, when calculating the optimal matching current, it can be calculated through the following process:

[0198] (a) Initialize and take as the root node voltage V r , and assign initial values to the voltages of other nodes Given the active power distribution factor α that satisfies, assign the initial value to the boundary mismatch power

[0199] (b) According to take as the new load value.

[0200] (c) Given the load data, calculate the branch power and current through a single forward operation.

[0201] (d) Trace back from the root node to calculate the voltages of each node.

[0202] (e) Determine whether the voltage difference between two adjacent iterations is less than the given convergence index. If it is satisfied, stop; otherwise, return to (b), thus completing the iterative calculation process of the optimal matching current.

[0203] Optionally, in the power grid fluctuation detection method provided in the embodiments of the present application, determining the power grid fluctuation condition of the target area according to the calculation result and the parameter index set includes: obtaining the index values of each evaluation index in the calculation result from the parameter index set, and comparing the evaluation index to which each index value belongs with the corresponding evaluation criterion to obtain a plurality of comparison results; determining the power grid fluctuation condition according to the plurality of comparison results.

[0204] It should be noted that the parameter index set refers to a set of quantitative indexes for evaluating the operation state of the power grid, such as the maximum value, minimum value, and average value of voltage, the configured amount, usage amount, and usage rate of reactive power resources, as well as reactive power balance and reserve rate, etc. The calculation result is the data obtained after implementing the analysis method of the present invention, and it includes the specific values of each reactive power voltage evaluation index. The evaluation criterion is the reference range or threshold set for each index, which is used to judge whether the value of the index is normal, whether it is high, low, or within the safe range.

[0205] Specifically, in the case of obtaining the final power flow calculation result, the index interval of each index in the parameter index set can be obtained, and it can be judged whether each parameter in the calculation result is located in the corresponding index interval. In the case of being located in the index interval, it can be determined that the parameter is normal; in the case of not being located in the index interval, it is determined that the parameter is abnormal, that is, it indicates that the power grid has fluctuations. Furthermore, according to the comparison relationship between each parameter and the corresponding index interval, it is determined whether there are fluctuations in the regional power grid.

[0206] For example, assume that a specific load-side regional power grid is being evaluated, and this area contains multiple 110 kV substations. First, extract data from the calculation result. For example, the maximum value of the 110 kV bus voltage is 1.05 pu, the minimum value is 0.98 pu, and the average value is 1.01 pu. Next, check the evaluation criterion. Assume that the maximum value does not exceed 1.05 pu, the minimum value is not lower than 0.95 pu, and the average value remains within the range of 1.0 pu ± 5%. Compare these index values with the evaluation criterion, and it is found that the maximum value and the average value both meet the standard, but the minimum value is slightly lower than the standard lower limit.

[0207] Further compare the configuration and usage of reactive power resources. Assume that the configured reactive power of the reactive power capacitor is 100 MVar, the currently input reactive power is 80 MVar, and the input rate is 80%. The evaluation criterion requires that the input rate is not lower than 90%. The comparison result shows that the input rate of the reactive power capacitor is lower than the standard.

[0208] Combining these comparison results, it can be determined that there is a certain risk of voltage fluctuation in this regional power grid. Especially during peak load periods, the bus voltage may be low. Although the reactive power resources are adequately configured, their utilization efficiency is not high, which may affect the power grid's response ability to voltage fluctuations, and more reactive power resources need to be called to improve voltage stability.

[0209] In this embodiment, by carefully comparing each index value in the calculation results with the evaluation criteria, the operation risks of the regional power grid can be accurately identified, especially the problems of voltage fluctuation and reactive power imbalance. This precise evaluation mechanism helps to timely adjust the power grid operation strategy, optimize the reactive power resource allocation, ensure the stability and security of the power grid operation, avoid risks such as voltage over-limit and equipment overload, and thus improve the overall operation quality of the power grid.

[0210] Optionally, in the power grid fluctuation detection method provided in the embodiment of the present application, a power flow calculation is performed on the power grid structure model using the target power parameter set, and the calculation results include: inputting each power parameter in the target power parameter set into an integrated power flow calculation algorithm to obtain the calculation results. Among them, the integrated power flow calculation algorithm decomposes the power grid structure model into a high-voltage main power grid model and a medium-low voltage secondary power grid model through the master-slave splitting method. The high-voltage main power grid model contains the parameters of high-voltage side equipment, and the medium-low voltage secondary power grid model contains the parameters of medium-low voltage side equipment. In the high-voltage main power grid model, a decomposed power flow calculation is performed to obtain the power flow distribution of the high-voltage main power grid model. In the medium-low voltage secondary power grid model, based on the power flow distribution of the high-voltage main power grid model, a matching current state estimation and power flow calculation are performed to determine the power flow distribution of the medium-low voltage secondary power grid model, and the power flow calculation results of the high-voltage main power grid model and the medium-low voltage secondary power grid model are integrated to obtain the calculation results.

[0211] It should be noted that the target power parameter set contains real-time operation parameters for power flow calculation, such as the voltage of each node, the current of each branch, and the power of each power source and load. The integrated power flow calculation algorithm is also a comprehensive model that can simultaneously process the power flow calculations of the high-voltage main power grid and the medium-low voltage secondary power grid to achieve the overall power flow analysis of the power grid. The master-slave splitting method is a calculation strategy that divides a large and complex power grid into two parts, namely high voltage and medium-low voltage, for separate calculations and finally integrates the results. The matching current state estimation is also to estimate the current state of the medium-low voltage side in the medium-low voltage secondary power grid model based on the power flow distribution of the high-voltage main power grid model, providing initial conditions for the power flow calculation. The integration of power flow calculation results is also to combine the calculation results of the high-voltage main power grid model and the medium-low voltage secondary power grid model to form the power flow calculation results of the entire power grid.

[0212] Specifically, when performing power flow calculations, it is first necessary to collect real-time grid operation data, including but not limited to the voltage, current, and power on the high-voltage side, the voltage, current, and power on the medium- and low-voltage sides, as well as parameters such as the impedance and admittance of all equipment. These data are used as the input of the algorithm, and the entire power grid model is divided into a high-voltage main grid model and a medium- and low-voltage secondary grid model, corresponding to the equipment and parameters on the high-voltage side and the medium- and low-voltage sides respectively. Use methods such as the fast decoupled method or the Newton-Raphson method to calculate the power flow distribution of the high-voltage main grid model, that is, analyze the power flow situation on the high-voltage side. Using the calculation results on the high-voltage side, perform matching current state estimation to obtain the current state on the medium- and low-voltage sides. After obtaining the state estimation, perform power flow calculations on the medium- and low-voltage sides to analyze the power flow situation. In the medium- and low-voltage secondary grid model, use the electrical parameters (such as voltage, current, and power) on the medium- and low-voltage sides to determine the power flow distribution. Finally, integrate the power flow calculation results of the high-voltage main grid model and the medium- and low-voltage secondary grid model to obtain the calculation results.

[0213] In this embodiment, the power grid is segmented by the master-slave splitting method, and the power flows on the high-voltage side and the medium- and low-voltage sides are calculated separately. Finally, the results are integrated, which not only improves the calculation speed and accuracy, but also solves the problem of poor coordination caused by the independent calculation of the high-voltage and medium- and low-voltage power grids in the traditional method. In practical applications, this method can help power system operators detect and handle voltage fluctuations and reactive power imbalance problems in a timely manner, avoid equipment overload and unstable grid operation, thereby improving the operation efficiency, stability, and safety of the power grid. For example, in the actual operation of the North China Power Grid, using this method can quickly and accurately identify abnormal power flows in specific areas, and timely adjust reactive power compensation and voltage control strategies to maintain the reliability of grid operation.

[0214] It should be noted that the master-slave splitting method is also:

[0215] Let the complex voltage of the main grid nodes be The complex voltage of the distribution network nodes is The main and distribution networks are connected through boundary nodes, and the complex voltage of the boundary nodes is Then the global power flow calculation can be reduced to the solution problem of the following non-linear algebraic equations:

[0216]

[0217] Then the equations (1) can be split into:

[0218]

[0219] Equation (1) is the main power flow equation, and equations (2)(3) are the distribution power flow equations. The complex power injected from the boundary nodes into the distribution network is used as the intermediate variable for master-slave splitting iteration.

[0220] According to the boundary system voltage Solve the distribution power flow equation to obtain the distribution system voltage And from and Calculate the injection power of the distribution network

[0221] From the injection power of the distribution network Solve the main power flow equation to obtain the transmission system voltage vector

[0222] Judge the maximum value of the modulus of the complex voltage difference of each boundary node between two adjacent iterations Whether it is less than the given convergence index. If so, the global power flow iteration converges; otherwise, k = k + 1, and go to (2) and (3).

[0223] However, according to the convergence theory of the master-slave splitting method, if the above master-slave splitting method has good convergence, the following requirements are required:

[0224] ① In the main power grid, the boundary node voltage changes little with the injection power of the distribution network.

[0225] ② In the distribution network, the boundary injection power changes little with the root node voltage.

[0226] For the structure with loops between the feeders of the distribution network, due to the existence of circulating power closely related to the root node voltage, it is difficult to meet the above second requirement, which deteriorates the convergence of this traditional master-slave splitting method when solving the global power flow of the distribution network with loops, and even fails to converge.

[0227] To solve this problem, rewrite Equation (1) as:

[0228]

[0229] The introduced in Equations (4) and (5) is called the boundary virtual power, which is the new intermediate variable of the master-slave splitting iteration. Compared with Equations (2) and (3), Equations (4) and (5) only split the global power system into different master-slave systems. When the distribution network contains loops, how to appropriately construct the boundary virtual power so that the new intermediate variable of the master-slave splitting iteration satisfies the requirement of being smaller, then the convergence of the master-slave splitting method is expected to be improved. Therefore, how to construct the boundary virtual power becomes the key problem.

[0230] Figure 3 is a schematic diagram of a master-slave splitting method based on the equivalence of the distribution network provided by an embodiment of the present application, as Figure 3As shown, its physical meaning is that in the new master-slave splitting iteration, the distribution equivalent network is incorporated into the main power grid to form a new main transmission system. At the same time, the equivalent network is removed from the distribution network to form a new distribution subsystem, and the new distribution subsystem is equivalent to a radial distribution subsystem. Further extended to a distribution network with k feeders and complex loops. Keep k feeder root nodes, perform Gaussian elimination on the distribution network admittance matrix to obtain the distribution network equivalent admittance matrix The negative of its off-diagonal elements is the loop admittance between feeders.

[0231] In the global power flow calculation, when there are loops between the feeders of the distribution network, the equivalent branches of the distribution network need to be taken into account in the main power grid. Therefore, the main power grid at this time is no longer the original main power grid, but the main power grid with the relevant equivalent branches of the distribution network added.

[0232] Finally, the correction is reflected in the main power grid admittance matrix, and the self-admittance and mutual-admittance elements of the corresponding boundary nodes (load nodes of the main power grid) are modified; once the admittance matrix is formed, it remains fixed during the global power flow calculation process.

[0233] It should be noted that if the fast decoupled method is used for the main power grid power flow calculation, considering that the r / x in the distribution network may be large and the r / x of its equivalent branches may also be large, directly taking these equivalent branches into account in the main power grid may affect the convergence of the fast decoupled method of the main power grid. To solve this problem, according to the need, the impedance angle of the equivalent branches can be changed, which can improve the convergence of the fast decoupled method of the main power grid on the premise of little impact on the global power flow convergence.

[0234] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0235] The embodiment of the present application also provides a device for detecting power grid fluctuations. It should be noted that the device for detecting power grid fluctuations in the embodiment of the present application can be used to execute the method for detecting power grid fluctuations provided by the embodiment of the present application. The following introduces the device for detecting power grid fluctuations provided by the embodiment of the present application.

[0236] Figure 4 is a schematic diagram of the device for detecting power grid fluctuations provided by the embodiment of the present application. As Figure 4 shown, the device includes: a first acquisition unit 41, a first determination unit 42, a second acquisition unit 43, a calculation unit 44, and a second determination unit 45.

[0237] The first acquisition unit 41 is configured to generate a high-voltage distribution network area model and a medium- and low-voltage distribution network area model within the target area, and combine the high-voltage distribution network area model and the medium- and low-voltage distribution network area model into a power grid structure model of the target area, where the high-voltage distribution network area model is a model of a power grid area with a node voltage greater than a preset voltage, and the medium- and low-voltage distribution network area model is a model of a power grid area with a node voltage less than or equal to the preset voltage.

[0238] The first determination unit 42 is configured to respectively determine the parameter indexes of each load node in the high-voltage distribution network area model and the medium- and low-voltage distribution network area model, and obtain a parameter index set.

[0239] The second acquisition unit 43 is configured to acquire the power parameters of each load node in the power grid structure model, obtain an initial power parameter set, and correct the abnormal parameters in the initial power parameters to obtain a target power parameter set.

[0240] The calculation unit 44 is configured to perform a power flow calculation on the power grid structure model using the target power parameter set to obtain a calculation result.

[0241] The second determination unit 45 is configured to determine the power grid fluctuation condition of the target area according to the calculation result and the parameter index set.

[0242] The power grid fluctuation detection device provided by the embodiment of the present application generates a high-voltage power distribution network area model and a medium- and low-voltage power distribution network area model in a target area through a first acquisition unit 41, and combines the high-voltage power distribution network area model and the medium- and low-voltage power distribution network area model into a power grid structure model of the target area. Among them, the high-voltage power distribution network area model is a model of a power grid area where the node voltage is greater than a preset voltage, and the medium- and low-voltage power distribution network area model is a model of a power grid area where the node voltage is less than or equal to the preset voltage; a first determination unit 42 respectively determines the parameter indexes of each load node in the high-voltage power distribution network area model and the medium- and low-voltage power distribution network area model to obtain a parameter index set; a second acquisition unit 43 acquires the power parameters of each load node in the power grid structure model to obtain an initial power parameter set, and corrects the abnormal parameters in the initial power parameters to obtain a target power parameter set; a calculation unit 44 performs a power flow calculation on the power grid structure model using the target power parameter set to obtain a calculation result; a second determination unit 45 determines the power grid fluctuation condition of the target area according to the calculation result and the parameter index set. It solves the problem that the detection accuracy of traditional voltage fluctuation detection methods for voltage fluctuations is relatively low in the related art. By segmenting the power grid structure model, determining the parameter index sets of the high-voltage power distribution network area model and the medium- and low-voltage power distribution network area model, and through the state estimation calculation method of integrated main and distribution, correcting the initial power parameter set to obtain a target power parameter set, and then using the target power parameter set to perform the integrated main and distribution power flow calculation to obtain all the power parameters of each load node in the power grid structure model, and then determining the fluctuation condition of the power grid according to each power parameter and the corresponding parameter index, thus achieving the technical effect of accurately determining the power grid fluctuation condition.

[0243] Optionally, in the power grid fluctuation detection device provided in the embodiments of the present application, the first acquisition unit 41 includes: a first acquisition module, configured to acquire an initial power grid model of a target area, and delete device models other than the first voltage level in the initial power grid model to obtain a first candidate power grid model; a first analysis module, configured to perform topological coloring analysis on the first candidate power grid model to obtain a plurality of first topological islands, where each first topological island includes a plurality of first load nodes electrically connected together; a second acquisition module, configured to acquire an initial power grid model of the target area, and delete device models other than the second voltage level in the initial power grid model to obtain a second candidate power grid model; a second analysis module, configured to perform topological coloring analysis on the second candidate power grid model to obtain a plurality of second topological islands; a third acquisition module, configured to acquire an initial power grid model of the target area, and delete device models other than the third voltage level in the initial power grid model to obtain a third candidate power grid model; a third analysis module, configured to perform topological coloring analysis on the third candidate power grid model to obtain a plurality of third topological islands; a first combination module, configured to combine the plurality of first topological islands, the plurality of second topological islands, and the plurality of third topological islands into a high-voltage distribution network area model.

[0244] Optionally, in the power grid fluctuation detection device provided in the embodiments of the present application, the first acquisition unit 41 includes: a fourth acquisition module, configured to acquire a transmission network model and a distribution network model in a target area; process the transmission network model, and establish a coordinated control area according to a plurality of target buses in the transmission network model; a processing module, configured to process the distribution network model, delete all disconnectors and circuit breakers in the distribution network model in the off state, and perform topological coloring analysis on the remaining distribution network model to obtain a plurality of fourth topological islands; a second combination module, configured to divide the target buses connected together in each fourth topological island into a distribution network area to obtain a plurality of control areas, and combine the plurality of control areas and the transmission network model into a medium- and low-voltage distribution network area model.

[0245] Optionally, in the power grid fluctuation detection device provided in the embodiments of the present application, the first determination unit 42 includes: a judgment module, configured to judge whether each power parameter in the initial power parameter set meets the corresponding parameter requirements; an estimation module, configured to acquire abnormal power parameters that do not meet the parameter requirements, and estimate the abnormal power parameters through an integrated state estimation algorithm to obtain a target power parameter set.

[0246] Optionally, in the power grid fluctuation detection device provided in the embodiments of the present application, the estimation module includes: a calculation sub-module, configured to determine an initial estimation parameter according to the abnormal power parameter, perform power flow calculation through the initial estimation parameter and the initial power parameter set, and iterate the initial estimation parameter according to the calculation result of the power flow calculation until the initial estimation parameter converges and then stop the iteration, and determine the initial estimation parameter corresponding to the stop of the iteration as the high-voltage estimation parameter and the medium- and low-voltage estimation parameter.

[0247] Optionally, in the power grid fluctuation detection device provided in the embodiments of the present application, the second determination unit 45 includes: a comparison module, configured to obtain the index values of each evaluation index in the calculation result from the parameter index set, and compare the evaluation index to which each index value belongs with the corresponding evaluation criterion to obtain a plurality of comparison results; a determination module, configured to determine the power grid fluctuation situation according to the plurality of comparison results.

[0248] Optionally, in the power grid fluctuation detection device provided in the embodiments of the present application, the calculation unit 44 includes: a calculation module, configured to input each power parameter in the target power parameter set into an integrated power flow calculation algorithm to obtain a calculation result, where the integrated power flow calculation algorithm decomposes the power grid structure model into a high-voltage main power grid model and a medium- and low-voltage secondary power grid model through the master-slave splitting method, where the high-voltage main power grid model contains the parameters of high-voltage side equipment, and the medium- and low-voltage secondary power grid model contains the parameters of medium- and low-voltage side equipment. In the high-voltage main power grid model, perform decomposed power flow calculation to obtain the power flow distribution of the high-voltage main power grid model. In the medium- and low-voltage secondary power grid model, based on the power flow distribution of the high-voltage main power grid model, perform matching current state estimation and power flow calculation to determine the power flow distribution of the medium- and low-voltage secondary power grid model, and integrate the power flow calculation results of the high-voltage main power grid model and the medium- and low-voltage secondary power grid model to obtain the calculation result.

[0249] The above-mentioned power grid fluctuation detection device includes a processor and a memory. The above-mentioned first acquisition unit 41, first determination unit 42, second acquisition unit 43, calculation unit 44, second determination unit 45, etc. are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to implement corresponding functions.

[0250] The processor contains a kernel, and the kernel retrieves the corresponding program unit from the memory. One or more kernels can be set, and by adjusting the kernel parameters, the problem that the traditional voltage fluctuation detection method in the related art has a low detection accuracy for voltage fluctuations is solved.

[0251] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash memory (flash RAM), and the memory includes at least one storage chip.

[0252] The embodiments of the present invention provide a computer-readable storage medium, on which a program is stored, and when the program is executed by a processor, a power grid fluctuation detection method is implemented.

[0253] The embodiments of the present invention provide a processor, and the processor is used to run a program, where when the program runs, a power grid fluctuation detection method is executed.

[0254] Figure 5 is a schematic diagram of an electronic device provided according to an embodiment of the present application. As Figure 5 shown, an embodiment of the present invention provides an electronic device. The electronic device 50 includes a processor, a memory, and a program stored on the memory and executable on the processor. When the processor executes the program, the steps of the above-mentioned power grid fluctuation detection method are implemented. The device herein may be a server, a PC, a PAD, a mobile phone, etc.

[0255] The present application also provides a computer program product which, when executed on a data processing device, is adapted to execute a program for initializing the steps of the above-mentioned power grid fluctuation detection method.

[0256] Those skilled in the art should understand that the embodiments of the present application may be provided as a method, a system, or a computer program product. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0257] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or multiple flows and / or blocks

[0258] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one or more of the flows Figure 1 or multiple flows and / or blocks

[0259] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide for implementing the process Figure 1 one process or multiple processes and / or blocks Figure 1 steps of the functions specified in one block or multiple blocks.

[0260] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0261] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of computer-readable media.

[0262] Computer-readable media includes permanent and non-permanent, removable and non-removable media and can store information by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media such as modulated data signals and carrier waves.

[0263] It should also be noted that the term "comprises", "comprising" or any other variant thereof is intended to cover a non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0264] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A method for detecting power grid fluctuations, characterized in that Including: Generating a high-voltage distribution network regional model and a medium- and low-voltage distribution network regional model within the target area, and combining the high-voltage distribution network regional model and the medium- and low-voltage distribution network regional model into the power grid structure model of the target area, where the high-voltage distribution network regional model is a model of the power grid area with node voltage greater than the preset voltage, and the medium- and low-voltage distribution network regional model is a model of the power grid area with node voltage less than or equal to the preset voltage; Respectively determining the parameter indexes of each load node in the high-voltage distribution network regional model and the medium- and low-voltage distribution network regional model to obtain a parameter index set; Obtaining the power parameters of each load node in the power grid structure model to obtain an initial power parameter set, and correcting the abnormal parameters in the initial power parameters to obtain a target power parameter set; Performing a power flow calculation on the power grid structure model using the target power parameter set to obtain a calculation result; Determining the power grid fluctuation condition of the target area according to the calculation result and the parameter index set.

2. The method according to claim 1, wherein Generating a high-voltage distribution network regional model within the target area includes: Obtaining the initial power grid model of the target area, and deleting the equipment models other than the first voltage level in the initial power grid model to obtain a first candidate power grid model; Performing topological coloring analysis on the first candidate power grid model to obtain a plurality of first topological islands, where each first topological island includes a plurality of first load nodes electrically connected together; Obtaining the initial power grid model of the target area, and deleting the equipment models other than the second voltage level in the initial power grid model to obtain a second candidate power grid model; Performing topological coloring analysis on the second candidate power grid model to obtain a plurality of second topological islands; Obtaining the initial power grid model of the target area, and deleting the equipment models other than the third voltage level in the initial power grid model to obtain a third candidate power grid model; Performing topological coloring analysis on the third candidate power grid model to obtain a plurality of third topological islands; Combining the plurality of first topological islands, the plurality of second topological islands and the plurality of third topological islands into the high-voltage distribution network regional model.

3. The method according to claim 1, wherein Generating a medium- and low-voltage distribution network regional model within the target area includes: Obtaining the transmission network model and the distribution network model within the target area; Processing the transmission network model and establishing a coordinated control area according to a plurality of target buses in the transmission network model; Processing the distribution network model, deleting all the disconnectors and circuit breakers in the off state in the distribution network model, and performing topological coloring analysis on the remaining distribution network model to obtain a plurality of fourth topological islands; Dividing the target buses connected together in each fourth topological island into a distribution network area to obtain a plurality of control areas, and combining the plurality of control areas and the transmission network model into the medium- and low-voltage distribution network regional model.

4. The method according to claim 1, wherein Obtaining the power parameters of each load node in the power grid structure model to obtain an initial power parameter set, and correcting the abnormal parameters in the initial power parameters to obtain a target power parameter set includes: Judging whether each power parameter in the initial power parameter set meets the corresponding parameter requirements; Obtain abnormal power parameters that do not meet the parameter requirements, and estimate the abnormal power parameters through an integrated state estimation algorithm to obtain the set of target power parameters.

5. The method according to claim 4, characterized in that Estimating the abnormal power parameters through an integrated state estimation algorithm to obtain the set of target power parameters includes: Determine initial estimation parameters according to the abnormal power parameters, perform power flow calculation through the initial estimation parameters and the initial power parameter set, and iterate the initial estimation parameters according to the calculation results of the power flow calculation until the initial estimation parameters converge and stop iterating. Then, determine the initial estimation parameters corresponding to the stop iteration as the updated initial estimation parameters, and use the updated initial estimation parameters to replace the abnormal power parameters in the initial power parameter set to obtain the set of target power parameters.

6. The method according to claim 1, characterized in that, Determining the power grid fluctuation situation of the target area according to the calculation results and the parameter index set includes: Obtain the index values of each evaluation index in the calculation results from the parameter index set, and compare the evaluation index to which each index value belongs with the corresponding evaluation criterion to obtain multiple comparison results; Determine the power grid fluctuation situation according to the multiple comparison results.

7. The method according to claim 1, wherein Performing power flow calculation on the power grid structure model using the set of target power parameters, and the calculation results obtained include: Input each power parameter in the set of target power parameters into an integrated power flow calculation algorithm to obtain the calculation results. Among them, the integrated power flow calculation algorithm decomposes the power grid structure model into a high-voltage main power grid model and a medium-low voltage secondary power grid model through the master-slave splitting method. The high-voltage main power grid model contains the parameters of high-voltage side equipment, and the medium-low voltage secondary power grid model contains the parameters of medium-low voltage side equipment. In the high-voltage main power grid model, perform decomposed power flow calculation to obtain the power flow distribution of the high-voltage main power grid model. In the medium-low voltage secondary power grid model, based on the power flow distribution of the high-voltage main power grid model, perform matching current state estimation and power flow calculation to determine the power flow distribution of the medium-low voltage secondary power grid model, and integrate the power flow calculation results of the high-voltage main power grid model and the medium-low voltage secondary power grid model to obtain the calculation results.

8. A detection device for power grid fluctuations, characterized in that, Includes: A first acquisition unit for generating a high-voltage distribution network area model and a medium-low voltage distribution network area model in the target area, and combining the high-voltage distribution network area model and the medium-low voltage distribution network area model into the power grid structure model of the target area. The high-voltage distribution network area model is a model of a power grid area where the node voltage is greater than a preset voltage, and the medium-low voltage distribution network area model is a model of a power grid area where the node voltage is less than or equal to the preset voltage; A first determination unit for respectively determining the parameter indexes of each load node in the high-voltage distribution network area model and the medium-low voltage distribution network area model to obtain a parameter index set; A second acquisition unit for acquiring the power parameters of each load node in the power grid structure model to obtain an initial power parameter set, and correcting the abnormal parameters in the initial power parameters to obtain a set of target power parameters; A calculation unit for performing a power flow calculation on the power grid structure model using the set of target power parameters to obtain a calculation result; A second determination unit for determining the power grid fluctuation condition of the target area according to the calculation result and the set of parameter indicators.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein when the executable program runs, it controls the device where the computer-readable storage medium is located to execute the power grid fluctuation detection method according to any one of claims 1 to 7.

10. An electronic device, characterized in that, Comprising: A memory storing an executable program; A processor for running the program, wherein when the program runs, it executes the power grid fluctuation detection method according to any one of claims 1 to 7.

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