Power distribution network operation fault detection method, system and device based on topology reconstruction and storage medium

Abstract

The invention discloses a power distribution network operation fault detection method, system and device based on topology reconstruction and a storage medium, and belongs to the technical field of power system automation, and the method comprises the steps: obtaining the real-time operation parameters of a power grid, and building a three-dimensional node coordinate system based on a power grid topology structure to calibrate a fault point location; matching an optimal power grid topological structure protection strategy of current power grid operation according to the real-time operation parameters of the power grid, and evaluating the operation state of the current power grid after matching; performing dynamic switching of a power grid topological structure protection strategy on the power grid based on the operation state evaluation result, and performing comparative analysis on fault point locations before and after switching of the power grid topological structure protection strategy so as to identify topological structure changes; and determining a network reconstruction direction and executing a self-healing control strategy by combining the relevance of the fault point locations before and after switching based on a topological structure change identification result. The fault detection efficiency and accuracy of the power distribution network are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system automation, and in particular to a power distribution network operation fault detection method, system, device and storage medium based on topology reconstruction. BACKGROUND

[0002] With the rapid development of smart grids, the importance of power distribution network topology reconstruction technology in improving power grid operation reliability and optimizing fault detection efficiency is increasingly prominent. As the terminal link of the power system, the power distribution network has a radial or open-loop ring topology structure, contains a large number of sectional switches, tie switches and distributed power sources. The traditional method determines the fault location by the action time sequence of current and voltage protection devices, but it is difficult to adapt to topology changes.

[0003] At present, the method of topology reconstruction is realized by real-time detection of the power change of each line switch and automatic updating of the change switch state in the network topology diagram, which significantly improves the intelligent level and operation convenience without manual intervention. However, the detection of abnormal power of the switch is only based on single-dimensional data analysis, lacking comprehensive processing capability of multi-source data, which may lead to inaccurate fault location. In addition, this method does not fully consider the dynamic interaction characteristics between nodes in the power distribution network, which may make it difficult to achieve efficient fault isolation and recovery under complex topology structure. The above problems show that the existing power distribution network operation fault detection technology based on topology reconstruction still has certain deficiencies in dynamic adaptability, multi-source data analysis capability and fault location accuracy. SUMMARY

[0004] In view of the above problems, the present application is proposed. Therefore, the present application provides a power distribution network operation fault detection method, system, device and storage medium based on topology reconstruction to solve the problems of insufficient fault location accuracy and fault detection efficiency, and poor adaptability to complex topology.

[0005] To solve the above technical problems, the present application provides the following technical solutions: a power distribution network operation fault detection method based on topology reconstruction, comprising: obtaining real-time operation parameters of the power grid, and establishing a three-dimensional node coordinate system based on the power grid topology structure to calibrate the fault point; matching the optimal power grid topology structure protection strategy for the current power grid operation according to the real-time operation parameters of the power grid, and evaluating the operation state of the current power grid after matching; based on the operation state evaluation result, dynamically switching the power grid topology structure protection strategy of the power grid, and comparing and analyzing the fault points before and after the switching of the power grid topology structure protection strategy to identify the topology structure change; based on the topology structure change identification result, determining the network reconstruction direction in combination with the correlation of the fault points before and after the switching, and executing the self-healing control strategy.

[0006] As a preferred scheme of the power distribution network operation fault detection method based on topology reconstruction, wherein: the three-dimensional node coordinate system is established based on the power grid topology structure to calibrate the fault point position, comprising: The three-dimensional node coordinate system maps each node in the power grid to a three-dimensional space, and each node has a unique coordinate value in the three-dimensional coordinate system; the position of the fault point in the three-dimensional coordinate system is calibrated by the positioning device.

[0007] As a preferred scheme of the power distribution network operation fault detection method based on topology reconstruction, wherein: the real-time operation parameters of the power grid include voltage fluctuation, current harmonic and load distribution, and the optimal power grid topology structure protection strategy for the current power grid operation is matched according to the real-time operation parameters of the power grid, comprising: using a multi-objective optimization algorithm to match and analyze the current power grid to obtain the optimal power grid topology structure protection strategy for the current power grid operation; the optimization objectives of the multi-objective optimization algorithm include minimizing voltage deviation, minimizing harmonic distortion rate, balancing load distribution and maximizing protection speed.

[0008] As a preferred scheme of the power distribution network operation fault detection method based on topology reconstruction, wherein: the evaluation of the operation state of the matched current power grid comprises: modeling the dynamic interaction characteristics of the power grid topology nodes of the power grid topology structure corresponding to the matched optimal power grid topology structure protection strategy, and constructing a power grid topology node dynamic interaction model; The power grid topology node dynamic interaction model is linearized by using a differential equation, the eigenvalues of the power grid topology node dynamic interaction model at the power grid topology nodes are obtained, and the real part and imaginary part of the eigenvalues are obtained by decomposing the eigenvalues; Based on the active power and reactive power at the power grid topology nodes, the average coupling of the power grid topology nodes is calculated; and the power grid topology loop stability is calculated according to the average coupling of the power grid topology nodes and the eigenvalues at the power grid topology nodes; If the power grid topology loop stability is not less than the preset evaluation threshold, it is judged that the power grid operation state is normal, and if the power grid topology loop stability is less than the preset evaluation threshold, it is judged that the power grid operation state is abnormal.

[0009] As a preferred scheme of the power distribution network operation fault detection method based on topology reconstruction, wherein: the dynamic switching of the power grid topology structure protection strategy of the power grid based on the operation state evaluation result comprises: If the power grid operation state is normal, the power grid topology structure protection strategy remains unchanged; if the power grid operation state is abnormal, the power grid topology structure protection strategy is dynamically switched.

[0010] As a preferred scheme of the power distribution network operation fault detection method based on topology reconfiguration, wherein: the fault point positions before and after the switching of the power grid topology structure protection strategy are compared and analyzed to identify the topology structure change, including: The fault point position coordinates before the switching of the power grid topology structure protection strategy and the fault point position coordinates after the switching of the power grid topology structure protection strategy are compared and analyzed, and the analysis result includes the disappearance of the fault point position after the switching, the coincidence of the fault point positions before and after the switching, and the non-coincidence of the fault point positions before and after the switching. When the analysis result is the disappearance of the fault point position after the switching, it is identified that the topology structure change based on the power grid topology structure protection strategy after the switching is effective, and the identification result is normal; when the analysis result is the coincidence or non-coincidence of the fault point positions before and after the switching, it is identified that the topology structure change based on the power grid topology structure protection strategy after the switching is ineffective, and the identification result is abnormal, and the correlation of the fault point positions before and after the switching is judged.

[0011] As a preferred scheme of the power distribution network operation fault detection method based on topology reconfiguration, wherein: based on the topology structure change identification result, the network reconfiguration direction is determined and the self-healing control strategy is executed in combination with the correlation of the fault point positions before and after the switching, including: The correlation is judged based on the time difference of the fault of the fault point positions before and after the switching, the spatial distance of the fault point positions before and after the switching, the current similarity of the fault point positions before and after the switching, and the resistance consistency of the fault point positions before and after the switching. When the correlation judgment result is greater than a preset threshold, the judgment result is strong correlation; when the correlation judgment result is not greater than the preset threshold, the judgment result is weak correlation. When the topology anomaly is detected, the network reconfiguration direction is determined and the self-healing control strategy is executed according to the correlation judgment result.

[0012] To solve the above technical problems, the present application provides the following technical scheme: a power distribution network operation fault detection system based on topology reconfiguration, comprising: A data acquisition terminal operation module is used to acquire real-time operation parameters of a power grid, and a three-dimensional node coordinate system is established based on a power grid topology structure to calibrate fault point positions. A topology structure strategy matching module is used to match an optimal power grid topology structure protection strategy for the current power grid operation according to the real-time operation parameters of the power grid. A power grid operation state evaluation module is used to evaluate the operation state of the current power grid after matching. A topology structure dynamic switching module is used to dynamically switch the power grid topology structure protection strategy of the power grid based on the operation state evaluation result. The control platform tracking and identification module is used to compare and analyze the fault locations before and after the power grid topology protection strategy switching in order to identify topology changes. The identification result output module is used to determine the network reconstruction direction and execute self-healing control strategies based on the identification results of topology changes and the correlation between fault points before and after the switchover.

[0013] The present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, characterized in that the processor executes the computer program to implement the steps of the aforementioned method for detecting faults in the operation of a distribution network based on topology reconfiguration.

[0014] The present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the steps of the aforementioned method for detecting faults in a distribution network based on topology reconfiguration.

[0015] The beneficial effects of this invention are as follows: This invention ensures the timeliness of fault detection by real-time monitoring of power grid operating parameters through a data acquisition terminal; it matches power grid topology protection strategies based on real-time power grid operating parameters, avoiding the limitations of traditional fixed strategies and improving the accuracy and flexibility of fault detection; by real-time assessment of the power grid status, combined with comprehensive analysis by the topology analysis unit and fault diagnosis unit, it can accurately determine the health status of the power grid, providing strong support for fault risk prediction; it dynamically switches power grid topology protection strategies, flexibly adjusting protection strategies according to the power grid operating status, effectively reducing the risk of fault occurrence; furthermore, by comparing and analyzing fault locations before and after the switch, it achieves effective identification of topology changes, providing a reliable basis for network reconfiguration and self-healing control, and feeding back early warning commands and topology change identification results to user terminals in real time, enabling users to respond quickly and take corresponding measures, ensuring the safe and stable operation of the distribution network. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of a method for detecting faults in a distribution network based on topology reconfiguration, provided as an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the system structure of a distribution network operation fault detection system based on topology reconfiguration, provided as an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are 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 skilled in the art without creative labor should belong to the protection scope of the present application.

[0020] Embodiment 1, Reference Figure 1 For an embodiment of the present application, the embodiment provides a power distribution network operation fault detection method based on topology reconstruction, comprising: S100: acquiring real-time operation parameters of the power grid, and establishing a three-dimensional node coordinate system based on the power grid topology structure to calibrate the fault point position; Further, the three-dimensional node coordinate system based on the power grid topology structure to calibrate the fault point position comprises: The three-dimensional node coordinate system maps each node in the power grid to a three-dimensional space, and each node has a unique coordinate value in the three-dimensional coordinate system; the position of the fault point position in the three-dimensional coordinate system is calibrated by a positioning device.

[0021] S200: matching the optimal power grid topology structure protection strategy of the current power grid operation according to the real-time operation parameters of the power grid, and evaluating the operation state of the current power grid after matching; Further, the real-time operation parameters of the power grid include voltage fluctuation, current harmonic and load distribution, and the optimal power grid topology structure protection strategy of the current power grid operation is matched according to the real-time operation parameters of the power grid, comprising: A multi-objective optimization algorithm is used to match and analyze the current power grid to obtain the optimal power grid topology structure protection strategy of the current power grid operation; the optimization objectives of the multi-objective optimization algorithm include minimizing voltage deviation, minimizing harmonic distortion rate, balancing load distribution and maximizing protection speed.

[0022] Specifically, the multi-objective optimization algorithm is expressed as:

[0023] Wherein, V represents the node voltage, U represents the rated voltage, THD represents the total harmonic distortion rate of the node current, MAX represents the maximum value of the node line load rate, MIN represents the minimum value of the node line load rate, T represents the fault clearing time, N represents the total number of power grid topology nodes, Wherein Indicates the node number. The function that minimizes the voltage deviation is the objective function. The function that optimizes to minimize the harmonic distortion rate. The function that optimizes the load distribution is the load balancer. The function that optimizes to maximize the protection of speed.

[0024] Furthermore, the evaluation of the current power grid operation status after matching includes: modeling the dynamic interaction characteristics of the power grid topology nodes for the power grid topology protection strategy corresponding to the optimal matching power grid topology structure, and constructing a dynamic interaction model of the power grid topology nodes; A differential equation linearization model of the dynamic interaction of power grid topology nodes is adopted to obtain the eigenvalues ​​of the dynamic interaction model of power grid topology nodes at the power grid topology nodes, and the eigenvalues ​​are decomposed to obtain the real and imaginary parts of the eigenvalues. The average coupling of the power grid topology nodes is calculated based on the active and reactive power at the nodes; the stability of the power grid topology loop is calculated based on the average coupling of the nodes and the eigenvalues ​​at the nodes. Specifically, the formula for calculating the average coupling of nodes in the power grid topology is as follows:

[0025] in, This represents the average coupling of nodes in the power grid topology. Indicates the node number of the power grid topology, and , and They represent the first The active and reactive power of each node. and They represent the first The active and reactive power of each node. It is a partial derivative.

[0026] Specifically, the stability of the power grid topology loop is calculated based on the average coupling of the nodes and the eigenvalues ​​at the nodes. The calculation formula is as follows:

[0027] in, Indicates the stability of the power grid topology loop. This represents the value corresponding to the real part of the eigenvalue of a node in the power grid topology. This represents the value corresponding to the imaginary part of the eigenvalues ​​of a node in the power grid topology. This represents the average coupling of nodes in the power grid topology. This represents the maximum coupling between nodes in the power grid topology. , is a weight coefficient, used to adjust the influence degree of the grid topology node characteristic value part and the average coupling part on the calculation of the grid topology loop stability, and .

[0028] Further, if the grid topology loop stability is not less than the preset evaluation threshold, it is judged that the grid operation state is normal, and if the grid topology loop stability is less than the preset evaluation threshold, it is judged that the grid operation state is abnormal. It should be pointed out that in the embodiment, the preset evaluation threshold can be set between 0.5-0.7 under normal circumstances, and if the grid is interconnected by multiple regional grids and is large in scale and requires high stability, the preset evaluation threshold can be set above 0.8.

[0029] Further, when the grid operation state is abnormal, insulation impedance detection and transient overvoltage analysis are performed based on the calibrated fault point data; the fault severity is comprehensively evaluated in combination with the two analysis results, and when the fault severity is higher than a preset topology reconstruction judgment threshold, the network reconstruction direction is determined in combination with the correlation of the fault points before and after switching and the self-healing control strategy is executed.

[0030] It should be pointed out that the preset topology reconstruction judgment threshold can be set between 0.7-0.9 in the embodiment.

[0031] Further, the insulation impedance detection measures the insulation resistance value of the fault point to determine whether there is an insulation fault, and the transient overvoltage analysis analyzes the transient overvoltage waveform in the grid to identify the fault type and position.

[0032] Specifically, a DC high voltage is applied to the fault point by using an insulation resistance tester, the leakage current under the applied voltage is measured, the insulation resistance value is calculated according to Ohm's law, and if the measured insulation resistance value is much lower than the standard value, it can be determined that there is an insulation fault. The waveform data of the transient overvoltage in the grid operation process is collected in real time to identify the fault type: When the fault type is single-phase ground fault, the transient overvoltage waveform presents the characteristics of single-phase voltage sudden rise and slight drop of the other two-phase voltage; when the fault type is phase-to-phase short circuit fault, the fault phase voltage will drop sharply. The arrival time difference of the transient waveforms of multiple measuring points is analyzed, the length of the grid line and the wave speed are combined to calculate the position of the fault point, and the calculation formula is:

[0033] wherein, is the distance from the fault point to the measuring point, is the wave speed, is the arrival time difference of the waveforms of the two measuring points. If it is judged that there is an insulation fault, and both types of faults occur, the fault severity is higher than the comprehensive evaluation fault severity.

[0034] Specifically, when the power grid operating state is evaluated and determined to be abnormal, the numerical calculation process of the fault severity includes steps A1-A3: Step A1: The actual insulation resistance of the fault point is collected by the insulation resistance tester, and the standard insulation resistance value of the grid node of this type under standard working conditions is called. The actual insulation resistance and the standard insulation resistance are calculated by ratio. If the actual value is greater than or equal to the standard value, the ratio is recorded as 1, indicating that the insulation performance is normal. If the actual value is less than the standard value, the actual ratio is directly used. The smaller the ratio, the more serious the insulation fault. Step A2: The transient overvoltage amplitude of the fault point is collected in real time, the rated voltage of the power grid is called, and the ratio of the transient overvoltage amplitude to the rated voltage is calculated. At the same time, according to the fault diagnosis result, the fault type weight is determined, wherein the weight of the interphase short circuit fault is set to 1.0, the weight of the single-phase ground fault is set to 0.6, and the weight when there is no above-mentioned fault is set to 0. The transient overvoltage abnormal correlation value is obtained by multiplying the transient overvoltage ratio by the corresponding fault type weight. Step A3: According to the safety operation demand of the distribution network, the weights of the insulation state and the transient overvoltage in the fault severity evaluation are determined by the analytic hierarchy process and the Delphi method, wherein the weight of the insulation state accounts for 40%, and the weight of the transient overvoltage accounts for 60%. First, the insulation resistance ratio is obtained by subtracting 1, and then the influence degree of the insulation fault is multiplied by the corresponding weight, and the transient overvoltage abnormal correlation value is multiplied by the corresponding weight, to obtain the quantitative value of the fault severity. The value of the value is 0 to 1, and the larger the value, the higher the fault severity. The value can be directly compared with the preset topology reconstruction judgment threshold value. When the quantitative value is higher than the preset topology reconstruction judgment threshold value, the subsequent network reconstruction direction determination and self-healing control strategy execution process is triggered.

[0035] S300: Based on the operating state evaluation result, the power grid topology structure protection strategy is dynamically switched, and the fault points before and after the power grid topology structure protection strategy are compared and analyzed to identify the topology structure change. Further, the dynamic switching of the power grid topology structure protection strategy based on the operating state evaluation result includes: If the power grid operating state is normal, the power grid topology structure protection strategy remains unchanged; if the power grid operating state is abnormal, the power grid topology structure protection strategy is dynamically switched.

[0036] Specifically, the specific process of dynamically switching the power grid topology structure protection strategy includes steps B1-B4: Step B1: Real-time acquisition of voltage, current, active power and power flow direction of each node of the power distribution network, construction of a static topology model combined with the power grid topology structure, dynamic updating of the real-time topology structure according to the real-time operation data, and continuous evaluation of the power grid topology loop stability and operation state through the topology analysis unit; Step B2: When the evaluation result is normal operation state, the system maintains the current basic protection strategy, which is centered on guaranteeing stable operation of the power grid and minimizing energy consumption; once the evaluation finds that the power grid is operating abnormally, the system immediately starts the strategy switching process, matches the optimal adaptive strategy from the preset protection strategy library through the preset multi-objective optimization algorithm, combined with the real-time topology structure, fault point information, fault type and severity, the strategy library covers special protection schemes for different topology structures, fault types and distributed power access scenarios, including directional overcurrent protection, fast-acting intelligent distributed protection, overcurrent threshold adaptive setting, etc. Step B3: In the switching execution phase, real-time coordination between the master station and terminal devices such as sectionalizing switches and distributed power controllers is achieved through optical fiber or 5G communication, the original protection strategy is first locked out, and then the action threshold, timing coordination logic and lockout conditions of each protection device are adaptively adjusted according to the matched optimal strategy, if distributed power or nodes with energy storage are involved, the protection setting and power flow control logic of the corresponding area need to be adjusted synchronously to ensure no misoperation or refusal to operate during the switching process; Step B4: After the switching is completed, the adaptability of the new protection strategy is verified by continuously monitoring the power grid operation data and fault point changes, if the topology structure changes again, repeat steps B1-B3 to dynamically match and switch the new protection strategy, always ensuring that the protection strategy is accurately adapted to the real-time operation state and topology structure of the power grid.

[0037] Further, the fault point coordinates before and after the switching of the power grid topology structure protection strategy are compared and analyzed to identify topology structure changes, including: The fault point coordinates before and after the switching of the power grid topology structure protection strategy are compared and analyzed to identify topology structure changes, including: When the analysis result is that the fault point disappears after switching, it is identified that the topology structure change based on the power grid topology structure protection strategy after switching is effective, the identification result is normal; when the analysis result is that the fault points before and after switching coincide or do not coincide, it is identified that the topology structure change based on the power grid topology structure protection strategy after switching is invalid, the identification result is abnormal, and the relevance of the fault points before and after switching is judged.

[0038] S400: Based on the topology change identification results, combined with the correlation of fault points before and after the switch, determine the network reconstruction direction and execute the self-healing control strategy. Furthermore, based on the topology change identification results, and combined with the correlation between fault locations before and after the switchover, the network reconstruction direction is determined and self-healing control strategies are implemented, including: The correlation is determined based on the time difference of the fault location before and after the switch, the spatial distance between the fault locations before and after the switch, the current similarity between the fault locations before and after the switch, and the impedance consistency between the fault locations before and after the switch. Specifically, the formula for determining relevance is as follows:

[0039] in, This indicates the result of the correlation judgment. This indicates the time difference between when the fault occurred at the fault location before and after the switchover. This indicates the spatial distance between the fault locations before and after the switchover. This indicates the similarity of the current at the fault location before and after the switching. This indicates the consistency of impedance at the fault location before and after the switchover. and This indicates the preset maximum time threshold and maximum distance threshold. , , as well as These represent the weights.

[0040] It should be noted that in this implementation, the maximum time threshold can be set to 10ms-20ms; the maximum distance threshold can be set to 10km-15km.

[0041] Furthermore, when the correlation judgment result is greater than the preset threshold, the judgment result is a strong correlation; when the correlation judgment result is not greater than the preset threshold, the judgment result is a weak correlation. When a topology anomaly is detected, the network reconstruction direction is determined based on the correlation judgment results and a self-healing control strategy is executed.

[0042] Specifically, if the correlation judgment result is determined to be strong correlation, it indicates that there is a direct correlation between the fault points before and after the switchover. In this case, the network reconstruction direction is fault branch isolation and load transfer. The self-healing control strategy is to prioritize locating the topology branch where the fault point is located, determine the fault line switch that needs to be disconnected and the tie switch that needs to be closed, and transfer the load of the fault branch to the adjacent healthy topology branch to avoid load interruption. If the correlation judgment result is determined as weak correlation, it indicates that there is no direct correlation between the fault points before and after switching, at this time, the network reconstruction direction is global topology optimization, and the self-healing control strategy is: by analyzing the load distribution and voltage level of the overall topology of the distribution network, the topology structure of the region where the weak correlation fault point is located is preferentially adjusted, such as adding a tie switch, optimizing the access node of the distributed power supply.

[0043] It should be noted that in the present embodiment, the preset threshold value can be set to 0.7; for example, when the preset threshold value is 0.7, if , the judgment result is strong correlation, otherwise, if , the judgment result is weak correlation.

[0044] In the present embodiment, it should be specifically noted that the difference between the present embodiment and the prior art mainly lies in that the present application ensures the timeliness of fault detection by real-time monitoring of power grid operation parameters through a data acquisition terminal; avoids the limitations of traditional fixed strategies and improves the accuracy and flexibility of fault detection by matching power grid topology structure protection strategies according to real-time power grid operation parameters; accurately judges the health status of the power grid through real-time evaluation of the power grid state, combined with comprehensive analysis of topology analysis and fault diagnosis, to provide strong support for fault risk prediction; dynamically switches the power grid topology structure protection strategy, flexibly adjusts the protection strategy according to the operation state of the power grid, and effectively reduces the risk of fault occurrence; through comparison and analysis of the fault points before and after switching, effective identification of the change of the topology structure is realized, providing a reliable basis for network reconstruction and self-healing control; the warning instruction and the identification result of the change of the topology structure are fed back to the user terminal in real time, so that the user can quickly respond and take corresponding measures, ensuring the safe and stable operation of the distribution network.

[0045] Embodiment 2, refer to Figure 2 , as an embodiment of the present application, the embodiment provides a distribution network operation fault detection system based on topology reconstruction, comprising: a data acquisition terminal operation module for acquiring real-time operation parameters of the power grid, and establishing a three-dimensional node coordinate system based on the power grid topology structure to calibrate the fault point; a topology structure strategy matching module for matching the optimal power grid topology structure protection strategy for the current power grid operation according to the real-time operation parameters of the power grid; a power grid operation state evaluation module for evaluating the operation state of the current power grid after matching; a topology structure dynamic switching module for dynamically switching the power grid topology structure protection strategy of the power grid based on the operation state evaluation result; a control platform tracking and identification module for comparing and analyzing the fault points before and after switching of the power grid topology structure protection strategy to identify the change of the topology structure; The recognition result output module is configured to determine a network reconstruction direction and execute a self-healing control strategy based on the topology structure change recognition result and the correlation of the fault points before and after switching.

[0046] Further, the power grid operation state evaluation module further comprises a topology analysis unit and a fault diagnosis unit. The topology analysis unit is configured to analyze the coupling relationship between nodes after matching the power grid topology structure, model the dynamic interaction characteristics of the power grid topology nodes, analyze the power grid topology loop stability through eigenvalue decomposition, and evaluate the power grid operation state according to the power grid topology loop stability. The fault diagnosis unit is configured to diagnose the fault points in the data acquisition terminal operation module after matching the power grid topology structure.

[0047] Further, the control platform tracking and recognition module further comprises a fault point comparison and analysis unit and a topology structure change recognition unit. The fault point comparison and analysis unit is configured to track the fault point coordinates through the positioning device after switching the power grid topology structure protection strategy, and compare and analyze the fault points before and after switching. The topology structure change recognition unit is configured to effectively recognize the topology structure change according to the comparison and analysis results of the fault points before and after switching.

[0048] In an optional embodiment, the data acquisition terminal collects power grid operation parameters in real time through intelligent sensing devices deployed at key nodes of the distribution network. The intelligent sensing devices include voltage sensors, current sensors, and load sensors, which can monitor voltage fluctuations, current harmonics, and load distribution in the power grid in real time. By uploading the data collected by these sensors to the data acquisition terminal operation module, comprehensive monitoring of the power grid operation state can be achieved. The data acquisition terminal establishes a three-dimensional node coordinate system based on the power grid topology structure. The three-dimensional node coordinate system maps each node in the power grid to a three-dimensional space, and each node has a unique coordinate value in the three-dimensional coordinate system. The positioning device accurately determines the position of the fault point in the three-dimensional coordinate system.

[0049] In an optional embodiment, the topology structure strategy matching module matches the power grid topology structure protection strategy based on the power grid operation parameters collected by the data acquisition terminal operation module and according to a multi-objective optimization algorithm.

[0050] In an optional embodiment, after matching the power grid topology structure, the dynamic topology analysis unit is used to analyze the coupling relationship between nodes, model the dynamic interaction characteristics of the power grid topology nodes, analyze the power grid topology loop stability through eigenvalue decomposition, and evaluate the power grid operation state according to the power grid topology loop stability.

[0051] In this embodiment, it needs to be specifically pointed out that the specific content of the topology analysis unit is as follows: Based on the active power and the reactive power at the node, the average coupling of the power grid topology node is analyzed; The dynamic interaction characteristics of the power grid topology node are modeled, the differential equation linearization power grid topology node dynamic interaction model is adopted, the eigenvalues of the power grid topology node dynamic interaction model at the power grid topology node are obtained, and the real part and the imaginary part of the eigenvalues are obtained by decomposition; According to the average coupling of the power grid topology node and the eigenvalues at the power grid topology node, the power grid topology loop stability is calculated, and the power grid operating state is evaluated according to the power grid topology loop stability: when the power grid topology loop stability is greater than or equal to the preset evaluation threshold, it is judged that the power grid operating state is normal, otherwise, when the power grid topology loop stability is less than the preset evaluation threshold, it is judged that the power grid operating state is abnormal.

[0052] In an optional embodiment, after the power grid topology structure is matched, the fault point position calibrated in the data acquisition terminal running module is diagnosed by the fault diagnosis unit.

[0053] In this embodiment, it needs to be specifically pointed out that the specific content of the fault diagnosis unit is as follows: The fault diagnosis unit is based on the fault point position data provided by the data acquisition terminal running module, and uses insulation impedance detection and transient overvoltage analysis technology to accurately diagnose the fault in the power grid: The insulation impedance detection measures the insulation resistance value of the fault point position to determine whether there is an insulation fault, and the transient overvoltage analysis identifies the fault type and position by analyzing the transient overvoltage waveform in the power grid; the insulation resistance tester is used to apply a direct current high voltage to the fault point position, the leakage current under the applied voltage is measured, and the insulation resistance value is calculated according to Ohm's law, if the measured insulation resistance value is much lower than the standard value, it can be determined that there is an insulation fault; The fault diagnosis unit combines the detection results of insulation impedance and transient overvoltage, and comprehensively evaluates the fault severity, and when the fault severity is higher than the topology reconstruction judgment threshold, sends a warning information to the identification result output module.

[0054] In an optional embodiment, the topology structure dynamic switching module dynamically switches the power grid topology structure protection strategy based on the power grid operating state evaluation result: If the power grid operating state is normal, the power grid topology structure protection strategy remains unchanged; if the power grid operating state is abnormal, the power grid topology structure protection strategy is dynamically switched.

[0055] In an optional embodiment, the fault point position comparison and analysis unit tracks the fault point position coordinates through the positioning device after switching the power grid topology protection strategy, compares and analyzes the fault point positions before and after switching, and the analysis results are respectively disappearance of the fault point position after switching, coincidence of the fault point positions before and after switching, and non-coincidence of the fault point positions before and after switching.

[0056] In an optional embodiment, the topology change identification unit identifies the effectiveness of the topology change according to the comparison and analysis results of the fault point positions before and after switching: When the fault point position after switching disappears, the topology change identification result is that the topology change based on the power grid topology protection strategy after switching is effective, and the identification result is normal. When the fault point positions before and after switching coincide, the topology change identification result is that the topology change based on the power grid topology protection strategy after switching is invalid, the identification result is abnormal, and the correlation of the fault point positions before and after switching is determined. When the fault point positions before and after switching do not coincide, the topology change identification result is that the topology change based on the power grid topology protection strategy after switching is invalid, the identification result is abnormal, and the correlation of the fault point positions before and after switching is determined.

[0057] In an optional embodiment, the identification result output module receives the early warning information sent by the fault diagnosis unit, generates a fault point position early warning instruction, outputs the early warning instruction and the topology change identification result to the user terminal, the user terminal performs a pre-warning operation according to the early warning instruction, and when detecting a topology anomaly, determines the network reconstruction direction according to the fault point positions before and after switching and executes a self-healing control strategy.

[0058] It should be explained that the difference between the present application and the prior art is mainly that the embodiment is provided with a data acquisition terminal operation module, a topology structure strategy matching module, a power grid operation state evaluation module, a topology structure dynamic switching module, a control platform tracking identification module and an identification result output module, the power grid operation parameters are monitored in real time through the data acquisition terminal to ensure the timeliness of fault detection, the power grid topology structure protection strategy is matched according to the real-time power grid operation parameters, the limitations of the traditional fixed strategy are avoided, and the accuracy and flexibility of fault detection are improved, the power grid state is evaluated in real time through the power grid operation state evaluation module, the comprehensive analysis of the topology analysis unit and the fault diagnosis unit is combined, the health condition of the power grid can be accurately judged, and strong support is provided for fault risk prediction, the power grid topology structure protection strategy is dynamically switched, the protection strategy is flexibly adjusted according to the power grid operation state, and the risk of fault occurrence is effectively reduced, the control platform tracking identification module realizes effective identification of the topology structure change by comparing and analyzing the fault points before and after switching, provides a reliable basis for network reconstruction and self-healing control, and the identification result output module feeds back the early warning instruction and the topology structure change identification result to the user terminal in real time, so that the user can respond quickly and take corresponding measures, and the safe and stable operation of the distribution network is ensured.

[0059] Embodiment 3 is an embodiment of the present application, which is different from the previous two embodiments: If the functions are realized in the form of software function units and sold or used as independent products, the functions can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the part of the present application that essentially contributes to the prior art or the part of the technical solutions can be embodied in the form of a software product, the computer software product is stored in a storage medium, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server or a network device) to execute all or part of the steps of the embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk and various program code storage media.

[0060] The logic and / or steps represented in the flow diagrams or otherwise described herein, for example, can be considered as a sequence of executable instructions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this specification, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium.

[0061] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can also be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example via an optical scanner, then compiled, interpreted, or otherwise processed, and stored in a computer memory in a form that can be later executed by a computer. In some embodiments, the computer-readable medium can be non-transitory.

[0062] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, or combinations thereof, can be used: a discrete logic circuit having logic gates for implementing logic functions upon data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0063] It should be noted that the above-mentioned embodiments are merely used to illustrate the technical solutions of the present application but not limit the present application, and although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalent replaced without departing from the spirit and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A method for detecting operational faults in a distribution network based on topology reconfiguration, characterized in that, include: Obtain real-time operating parameters of the power grid and establish a three-dimensional node coordinate system based on the power grid topology to pinpoint fault locations; The optimal power grid topology protection strategy is matched based on the real-time operating parameters of the power grid, and the operating status of the current power grid after matching is evaluated. Based on the operational status assessment results, the power grid topology protection strategy is dynamically switched, and the fault locations before and after the power grid topology protection strategy switching are compared and analyzed to identify topology changes. Based on the topology change identification results, and combined with the correlation between fault locations before and after the switchover, the network reconstruction direction is determined and a self-healing control strategy is executed.

2. The method for detecting operational faults in a distribution network based on topology reconfiguration as described in claim 1, characterized in that, Establishing a three-dimensional node coordinate system based on the power grid topology to pinpoint fault locations includes: The three-dimensional node coordinate system maps each node in the power grid to a three-dimensional space, and each node has a unique coordinate value in the three-dimensional coordinate system; the location of the fault point in the three-dimensional coordinate system is determined by the positioning device.

3. The method for detecting operational faults in a distribution network based on topology reconfiguration as described in claim 2, characterized in that, Real-time power grid operating parameters include voltage fluctuations, current harmonics, and load distribution. Protection strategies that match the optimal power grid topology based on these real-time operating parameters include: A multi-objective optimization algorithm is used to perform matching analysis on the current power grid to obtain the optimal power grid topology protection strategy for the current power grid operation. The optimization objectives of the multi-objective optimization algorithm include minimizing voltage deviation, minimizing harmonic distortion rate, balancing load distribution, and maximizing protection speed.

4. The method for detecting operational faults in a distribution network based on topology reconfiguration as described in claim 3, characterized in that, The evaluation of the current power grid operation status after matching includes: modeling the dynamic interaction characteristics of the power grid topology nodes for the power grid topology protection strategy corresponding to the optimal matching power grid topology structure, and constructing a dynamic interaction model of the power grid topology nodes; A differential equation linearization model of the dynamic interaction of power grid topology nodes is adopted to obtain the eigenvalues ​​of the dynamic interaction model of power grid topology nodes at the power grid topology nodes, and the eigenvalues ​​are decomposed to obtain the real and imaginary parts of the eigenvalues. The average coupling of the power grid topology nodes is calculated based on the active and reactive power at the nodes; the stability of the power grid topology loop is calculated based on the average coupling of the nodes and the eigenvalues ​​at the nodes. If the stability of the power grid topology loop is not less than the preset evaluation threshold, the power grid is judged to be operating normally; if the stability of the power grid topology loop is less than the preset evaluation threshold, the power grid is judged to be operating abnormally.

5. The method for detecting operational faults in a distribution network based on topology reconfiguration as described in claim 4, characterized in that, Dynamic switching of power grid topology protection strategies based on operational status assessment results includes: If the power grid is operating normally, the power grid topology protection strategy remains unchanged; if the power grid is operating abnormally, the power grid topology protection strategy is dynamically switched.

6. The method for detecting operational faults in a distribution network based on topology reconfiguration as described in claim 5, characterized in that, A comparative analysis of fault locations before and after the switching of power grid topology protection strategies is conducted to identify topology changes, including: The coordinates of the fault points before and after the power grid topology protection strategy switching are calibrated. The fault points before and after the switching are compared and analyzed. The analysis results include the disappearance of the fault points after the switching, the overlap of the fault points before and after the switching, and the non-overlap of the fault points before and after the switching. When the analysis result shows that the fault location disappears after the switch, the identification of the topology change based on the protection strategy of the power grid topology after the switch is effective and the identification result is normal; when the analysis result shows that the fault locations before and after the switch overlap or do not overlap, the identification of the topology change based on the protection strategy of the power grid topology after the switch is invalid, the identification result is abnormal, and the correlation judgment of the fault locations before and after the switch is triggered.

7. The method for detecting operational faults in a distribution network based on topology reconfiguration as described in claim 6, characterized in that, Based on the topology change identification results, and combined with the correlation between fault locations before and after the handover, the network reconstruction direction is determined and a self-healing control strategy is implemented, including: The correlation is determined based on the time difference of the fault location before and after the switch, the spatial distance between the fault locations before and after the switch, the current similarity between the fault locations before and after the switch, and the impedance consistency between the fault locations before and after the switch. When the correlation judgment result is greater than the preset threshold, the judgment result is strong correlation; when the correlation judgment result is not greater than the preset threshold, the judgment result is weak correlation. When a topology anomaly is detected, the network reconstruction direction is determined based on the correlation judgment results and a self-healing control strategy is executed.

8. A distribution network operation fault detection system based on topology reconfiguration, employing the distribution network operation fault detection method based on topology reconfiguration as described in any one of claims 1 to 7, characterized in that, include: The data acquisition terminal operation module is used to acquire real-time operating parameters of the power grid and establish a three-dimensional node coordinate system based on the power grid topology to pinpoint fault locations. The topology strategy matching module is used to match the optimal grid topology protection strategy for the current grid operation based on the real-time operating parameters of the grid. The power grid operation status assessment module is used to assess the current operation status of the power grid after matching. The topology dynamic switching module is used to dynamically switch the power grid topology protection strategy based on the operation status assessment results. The control platform tracking and identification module is used to compare and analyze the fault locations before and after the power grid topology protection strategy switching in order to identify topology changes. The identification result output module is used to determine the network reconstruction direction and execute self-healing control strategies based on the identification results of topology changes and the correlation between fault points before and after the switchover.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the distribution network operation fault detection method based on topology reconfiguration as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the distribution network operation fault detection method based on topology reconfiguration as described in any one of claims 1 to 7.

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