Single-power-supply ring-free radial main line topology identification method, device and system

Abstract

The invention discloses a single-power-supply loop-free radial main line topology identification method, device and system. The method comprises the following steps: constructing an initial node set and an initial current data set based on current data; comparing the current value of each node in the initial node set to generate a target pairing matrix, simplifying the initial node set and the initial current data set to obtain a simplified node set and a simplified current data set, and identifying a power supply node and an initial last-stage node set; performing iterative topology identification by using the initial last-stage node set, performing full combination summation on current values of nodes in each iteration to generate current values of candidate father nodes, matching the current values of the candidate father nodes with the current values in the simplified current data set, and if the matching succeeds, determining that the current values of the nodes are not matched with the current values in the simplified current data set; if yes, a father-son connection relation is established for the nodes in the initial last-stage node set until all father-son connection relations are recognized, and a main line topological structure is obtained, so that the accuracy of recognizing the topological relation in the single-power-supply loop-free radial network can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of topology identification, in particular to a single power supply non-loop radial main line topology identification method, device and system. BACKGROUND

[0002] In the management and operation process of low-voltage distribution network, accurate topology structure information is the basis for realizing key functions such as efficient operation and maintenance, fault positioning and elimination, and power quality optimization. However, many current low-voltage distribution networks, especially old distribution networks and village distribution networks, have the problem of unclear and inaccurate topology structure data. These problems are caused by factors such as historical data missing, complex topology structure, insufficient monitoring terminals, and data not updated in time after load adjustment. This inaccurate topology structure data not only affects the daily management of the power grid, but also brings great challenges to the construction of new digital low-voltage distribution networks. Therefore, accurately identifying the single power supply non-loop radial main line topology structure, which accounts for a large proportion in low-voltage distribution networks, is of great significance for improving power grid operation efficiency, ensuring power supply reliability, and promoting power grid digital transformation.

[0003] At present, the methods for realizing low-voltage distribution network topology identification and the household-transformer relationship identification contained therein mainly include carrier communication-based analysis method, power consumption information-based analysis method, current injection method, and stop-restart point analysis method. The carrier communication-based analysis method can only be used for nodes that can transmit and obtain carrier signals, and there is a phenomenon of area interference, which limits its application range. The power consumption information-based analysis method has poor identification effect on the topology structure inside the meter box. The current injection method requires replacing the carrier module of the electric meter when realizing topology identification, which has a large amount of construction. The stop-restart point analysis method cannot effectively identify the hierarchical relationship within the branch, and when the topology changes, new files need to be issued and new power-off and power-on need to be performed to update the topology, which has poor flexibility and real-time performance. These existing technologies have certain limitations and defects in actual application, and it is difficult to meet the requirements of real-time performance, accuracy and efficiency of topology identification in the construction of new digital low-voltage distribution networks. SUMMARY

[0004] The present application provides a single power supply non-loop radial main line topology identification method, device and system, which can improve the accuracy of identifying topology relationship in single power supply non-loop radial network.

[0005] An embodiment of the present application provides a single power supply non-loop radial main line topology identification method, comprising:

[0006] Obtaining current data collected by each monitoring terminal installed on the main line of the low-voltage distribution network at different times, and constructing an initial node set and an initial current data set based on the current data;

[0007] comparing the current values of each node in the initial node set at the same time to generate a target pairing matrix, simplifying the initial node set and the initial current data set according to the target pairing matrix to obtain a simplified node set after eliminating redundant nodes and a simplified current data set, and identifying a power supply node and an initial end node set from the simplified current data set;

[0008] iterative topology identification starting from the initial end node set, in each iteration, performing full combination summation on the current values of all nodes in the initial end node set to generate a plurality of candidate parent node current values, and performing consistency matching between each candidate parent node current value and the current values of all nodes in the simplified current data set at all sampling time points, if the current value of a certain node is consistent with a certain candidate parent node current value at all sampling time points, establishing a parent-child connection relationship for the corresponding node in the initial end node set with the node, until the parent-child connection relationship of all nodes in the simplified node set is identified, restoring the parent-child connection relationship corresponding to the simplified nodes according to the target pairing node set to obtain a complete single-power non-loop radial main line topology structure.

[0009] The embodiments of the present application can reflect the current changes of each node in the low-voltage distribution network by collecting current data of each monitoring terminal at different time points, avoiding topology identification errors caused by subsequent data loss or inaccuracy; the target pairing matrix can be generated by comparing the current values at the same time, which can quickly identify the nodes on the same line section; the initial node set and the initial current data set can be simplified to eliminate these redundant nodes, reducing the amount of data for subsequent calculation, avoiding the interference of redundant nodes on the topology identification process, and making the identification of the power supply node and the initial end node set more accurate; the parent-child connection relationship is gradually established by using an iterative method, avoiding errors that may be caused by processing a large amount of data at one time, ensuring that each connection relationship established is accurate and reliable, and finally achieving accurate identification of the parent-child connection relationship of all nodes in the simplified node set, greatly improving the accuracy of topology relationship identification in the single-power non-loop radial network; by restoring the parent-child connection relationship corresponding to the simplified nodes, the positions and connection relationships of the simplified nodes in the topology structure can be accurately restored, ensuring that the final obtained topology structure is complete and accurate, and achieving accurate identification of the topology relationship in the single-power non-loop radial network, providing accurate topology data support for the management and operation of the low-voltage distribution network. Compared with the prior art, the present application can improve the accuracy of identifying the topology relationship in the single-power non-loop radial network.

[0010] Further, the comparing the current values of each node in the initial node set at the same time to generate a target pairing matrix specifically comprises:

[0011] For each sampling time, compare the current value of each node in the initial node set with other nodes;

[0012] If the current values of two nodes at the sampling time are the same, record that the two nodes are successfully paired at this time, and record this pairing in the initial pairing success matrix, wherein the initial pairing success matrix is used to record the node pairs that are successfully paired and the total number of times they are successfully paired at all sampling times;

[0013] Traverse all sampling times to filter out all node pairs from the initial pairing success matrix, wherein the pairing success number is equal to the total number of sampling times, to form the target pairing matrix based on the node pairs, wherein the node pairs are nodes located on the same line segment.

[0014] By comparing the current values of each node at the same time to generate the target pairing matrix, the nodes located on the same line segment can be accurately identified, the accidental pairing caused by current fluctuations or measurement errors can be effectively excluded, and only the node pairs with the same current values at all sampling times can be identified as nodes on the same line segment, thereby significantly improving the accuracy of identifying the topological relationship in the single power source non-loop radial network.

[0015] Further, the initial node set and the initial current data set are simplified according to the target pairing matrix to obtain a simplified node set after removing redundant nodes and a simplified current data set, specifically:

[0016] Identify the second node in each node pair recorded in the target pairing matrix as the redundant node;

[0017] Assign the positions corresponding to all the redundant nodes in the initial node set to 0, and retain the original numbers of non-redundant nodes to obtain the simplified node set;

[0018] Assign the current data of all sampling times corresponding to the redundant nodes in the initial current data set to 0, and retain the current data corresponding to non-redundant nodes to obtain the simplified current data set.

[0019] In this way, the redundant information in the network can be effectively removed, making the simplified node set and current data set more concise and clear, reducing unnecessary interference factors, and making the subsequent topological relationship identification process more efficient and accurate.

[0020] Further, the power source node and the initial end node set are identified from the simplified current data set, specifically:

[0021] Traverse the simplified current data set to obtain the current values of each node at all sampling times;

[0022] By comparing the current values ​​of all nodes at each sampling time, the node whose current value is the largest among all nodes at each sampling time is determined as the power supply node, and the two nodes whose current values ​​are the smallest among all nodes at each sampling time are formed into the initial final-level node set.

[0023] This clearly identifies the locations of power nodes and final-level nodes, providing accurate reference points for subsequent topology identification.

[0024] Further, the step of summing the current values ​​of all nodes in the initial final-level node set to generate several candidate parent node current values ​​specifically involves:

[0025] All nodes in the initial final-level node set are selected in combination, wherein each selection includes at least two nodes;

[0026] For each node combination, the current values ​​of the node combination at the same sampling time are added together to obtain the first sum of the currents of the node combination at that sampling time;

[0027] By iterating through all sampling times, the second current sum of the node combination at all sampling times is obtained, and the current value of the candidate parent node at the corresponding sampling time is determined based on the second current sum, so as to form a number of candidate parent node current values.

[0028] By combining and summing all the node current values ​​of the initial final-level node set to generate several candidate parent node current values, the current relationship between nodes can be considered more comprehensively, and the connection relationship between nodes can be reflected more accurately, thereby improving the accuracy of topology identification.

[0029] Furthermore, after performing consistency matching between the current values ​​of each candidate parent node and the current values ​​of all nodes in the simplified current dataset at all sampling times, the method further includes:

[0030] If there is no node whose current value is consistent with the current value of a candidate parent node at all sampling times, then the node with the smallest current value among the currently unidentified nodes is added to the last-level node set, and the next iteration is performed based on the updated last-level node set.

[0031] By dynamically adjusting the set of final-level nodes, the actual topology of the network can be reflected more accurately. Especially in complex networks, this can effectively avoid identification errors caused by the lack of obvious current characteristics in some nodes, thereby significantly improving the accuracy and reliability of topology identification.

[0032] Furthermore, establishing a parent-child connection between the corresponding node in the initial set of final-level nodes and the node itself specifically involves:

[0033] constructing an initial identification matrix, wherein rows of the initial identification matrix correspond to nodes in the simplified node set one by one, and each row includes a node number and a parent node number of the node, and the parent node number is initially 0, indicating that the node is not identified;

[0034] when a candidate parent node current value is consistent with a current value of a node in the simplified current data set at all sampling times, updating parent node numbers of all end nodes participating in constituting the candidate parent node current value to a number of the consistent node;

[0035] if there are still nodes not identified in the initial identification matrix after one iteration is completed, extracting current values of the nodes not identified at each sampling time from the simplified current data set, adding a node with the smallest current value to the end node set, and performing current full combination addition and consistency matching again until parent node numbers of all nodes in the initial identification matrix are not 0;

[0036] perfecting the initial identification matrix according to node pairs recorded in the target pairing matrix to obtain a parent-child connection relationship matrix representing a complete topology.

[0037] In this way, by constructing an initial identification matrix and gradually updating parent-child connection relationships of nodes, misjudgments caused by current value fluctuations or node current similarity are effectively avoided, the accuracy of topology relationship identification is significantly improved, and more reliable data support is provided for management and optimization of a low-voltage distribution network.

[0038] Further, the perfecting the initial identification matrix to obtain the parent-child connection relationship matrix representing the complete topology structure comprises:

[0039] restoring a node number in the initial identification matrix that is assigned as 0 due to simplification to an actual number of a corresponding redundant node in the target pairing matrix, setting a parent node number of the newly restored node to a number of a corresponding pairing node with a smaller number in the target pairing matrix, to obtain a first result;

[0040] for a power supply node, keeping its parent node number as 0 to obtain a second result, and determining the parent-child connection relationship matrix representing the complete topology structure based on the first result and the second result.

[0041] In this way, the complete parent-child connection relationship matrix is obtained by perfecting the initial identification matrix, the accuracy of topology relationship identification is significantly improved, and thus the accuracy of identifying topology relationships in a single-power-supply non-loop radial network is improved.

[0042] Another embodiment of the present application also provides a single power supply non-loop radial main line topology identification device, comprising an acquisition module, a processing module and an identification module;

[0043] The acquisition module is configured to acquire current data collected by each monitoring terminal installed on a low-voltage distribution network main line at different time points, and construct an initial node set and an initial current data set based on the current data;

[0044] The processing module is configured to compare current values of each node in the initial node set at the same time point in pairs to generate a target pairing matrix, simplify the initial node set and the initial current data set according to the target pairing matrix, obtain a simplified node set and a simplified current data set after removing redundant nodes, and identify a power supply node and an initial end-stage node set from the simplified current data set;

[0045] The identification module is configured to perform iterative topology identification starting from the initial end-stage node set, add current values of all nodes in the initial end-stage node set in full combination in each iteration to generate a plurality of candidate parent node current values, and perform consistency matching between each candidate parent node current value and current values of all nodes in the simplified current data set at all sampling time points, and if current values of a certain node and a certain candidate parent node current value are consistent at all sampling time points, establish a parent-child connection relationship between the corresponding node in the initial end-stage node set and the node, until parent-child connection relationships of all nodes in the simplified node set are identified, restore the parent-child connection relationships corresponding to the simplified nodes according to the target pairing node set, and obtain a complete single power supply non-loop radial main line topology structure.

[0046] The embodiment of the application can reflect the current change of each node in the low-voltage distribution network, avoid the topology identification error caused by subsequent data loss or inaccuracy, generate a target pairing matrix by comparing the current values at the same time, quickly identify the nodes on the same line section, eliminate the redundant nodes by simplifying the initial node set and the initial current data set, reduce the data amount of subsequent calculation, avoid the interference of the redundant nodes on the topology identification process, make the identification of the power supply node and the initial end node set more accurate, gradually establish the parent-child connection relationship by iteration, avoid the error caused by processing a large amount of data at one time, ensure that the establishment of each connection relationship is accurate and reliable, finally realize the accurate identification of the parent-child connection relationship of all nodes in the simplified node set, greatly improve the accuracy of the topology relationship identification in the single-power-supply non-loop radial network, restore the position and connection relationship of the simplified nodes in the topology structure, ensure that the finally obtained topology structure is complete and accurate, realize the accurate identification of the topology relationship in the single-power-supply non-loop radial network, and provide accurate topology data support for the management and operation of the low-voltage distribution network. Compared with the prior art, the application can improve the accuracy of the topology relationship identification in the single-power-supply non-loop radial network.

[0047] Another embodiment of the application also provides a topology identification system, comprising: a table box comprising at least one sub-monitoring terminal;

[0048] a branch comprising at least one group of branch box devices or a branch node and being installed with at least three sub-monitoring terminals;

[0049] a transformer comprising a transformer and a total monitoring terminal on the low-voltage side of the transformer, the total monitoring terminal and each sub-monitoring terminal are installed on the main line, and one sub-monitoring terminal is installed on each phase line for collecting current data, the total monitoring terminal is used for receiving the current data sent by all sub-monitoring terminals and performing the steps of the single-power-supply non-loop radial main line topology identification method. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0051] Figure 1 is a flowchart of an embodiment of the single-power-supply non-loop radial main line topology identification method provided by the application;

[0052] Figure 2 is a schematic diagram of an arrangement position structure of a total monitoring terminal and a sub-monitoring terminal provided by the present application;

[0053] Figure 3 is a schematic diagram of an embodiment of a single power supply non-loop radial main line topology identification device provided by the present application;

[0054] Figure 4 is a schematic diagram of an embodiment of a topology identification system provided by the present application. DETAILED DESCRIPTION

[0055] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms “include” and “have” and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0057] In the description of the embodiments of the present application, the technical terms “first”, “second”, etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of “a plurality of” is two or more, unless otherwise explicitly and specifically limited.

[0058] Reference herein to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0059] In the description of the embodiments of the present application, the term "and / or" is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0060] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0061] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0062] In the management of low-voltage distribution network, accurate topology structure information is crucial, but many current distribution networks, especially old and village distribution networks, have the problem of unclear and inaccurate topology data, which affects the management of power grid and digital transformation. The existing topology identification methods such as carrier communication method, power consumption information analysis method, current injection method and stop and resume point analysis method have limitations, and it is difficult to meet the requirements of real-time, accuracy and efficiency of new digital low-voltage distribution network construction.

[0063] Reference Figure 1 In order to improve the accuracy of identifying the topology relationship in a single power source non-loop radial network, an embodiment of the present application provides a single power source non-loop radial main line topology identification method, comprising steps S101 to S103.

[0064] Step S101, acquiring current data collected by each monitoring terminal installed on the main line of the low-voltage distribution network at different times, and constructing an initial node set and an initial current data set based on the current data;

[0065] In some embodiments, the current data collected by each monitoring terminal at different time instants on the main line of the low-voltage power distribution network is obtained, specifically: first, a total monitoring terminal is deployed on the main line of the low-voltage side of the transformer substation, and a branch monitoring terminal is deployed on the branch main line and the meter box main line; then, each monitoring terminal (including the total monitoring terminal and the branch monitoring terminal) collects the current data of the A, B and C phases at the corresponding positions at different time instants with a preset sampling interval; finally, the branch monitoring terminal transmits the collected data to the total monitoring terminal through wireless communication, and the total monitoring terminal collects the current data of the low-voltage side of the transformer substation and the data received from the branch monitoring terminal, thereby obtaining the current data of each monitoring terminal at different time instants.

[0066] It should be noted that when the total monitoring terminal is installed, there are A, B and C phase lines at the same installation point, and one total monitoring terminal is installed at each of the A, B and C phase lines at the same installation point; when the branch monitoring terminal is installed, there are A, B and C phase lines at the same installation point, and one branch monitoring terminal is installed at each of the A, B and C phase lines at the same installation point, so that the total monitoring terminal and the branch monitoring terminal can be used to monitor the current at the installation position.

[0067] It should be noted that the sampling time interval can be set to be within 15 minutes, and the sampling can be performed once every 5 minutes, 12 times per hour, and 48 times per 4 hours, and the sampling time interval should balance the need for reducing the amount of communication data and the need for timely identification of topology changes.

[0068] In some embodiments, an initial node set and an initial current data set are constructed based on the current data, specifically: after obtaining the power data, all monitoring terminals are regarded as independent nodes, and the deployment numbers of the terminals (such as numbers 1, 2, 3, … n) are collected; then, the initial node set N1 = [1 2… n] is constructed, where the number of sampling time points is m = 48, and the numbers of the sampling time points are 1, 2, 3, … m; then, the sum of the three-phase current values of the A, B and C phase currents collected by each node (numbered i) at each sampling time point (numbered j, and the sampling interval is recommended to be ≤15 minutes) is calculated to obtain the current value of the node at the corresponding time, and the current value of each node at the corresponding time is arranged in the vertical dimension (1 to m) and the horizontal dimension (1 to n) of the sampling time to obtain the initial current data set ij The corresponding positions are filled in turn to construct the initial current data set

[0069] It should be noted that taking a 10kV / 400V power distribution transformer as an example, generally, the transformer converts 10kV into 380V / 220V, and the total monitoring terminal is installed near the low-voltage side outlet of the power distribution transformer, and in addition, as many branch monitoring terminals as possible are installed on the main line of the low-voltage power distribution network to monitor the current effective value at the installation position of each monitoring terminal. The arrangement position structure diagram of the total monitoring terminal and the branch monitoring terminal is as follows Figure 2As shown, the total number of nodes is n = 31, and the node numbers are 1, 2, 3, … n.

[0070] In step S102, the current values of each node in the initial node set at the same time are compared with each other to generate a target pairing matrix, and the initial node set and the initial current data set are simplified according to the target pairing matrix to obtain a simplified node set after removing redundant nodes and a simplified current data set, and a power supply node and an initial final node set are identified from the simplified current data set.

[0071] In some embodiments, the current values of each node in the initial node set at the same time are compared with each other to generate a target pairing matrix, specifically: for each sampling time, the current values of each node in the initial node set are compared with those of other nodes; if the current values of two nodes at the sampling time are the same, it is recorded that the two nodes are successfully paired at the time, and this pairing is recorded in an initial pairing success matrix, wherein the initial pairing success matrix is used to record the node pairs that are successfully paired and the total number of times they are successfully paired at all sampling times; all sampling times are traversed to filter out all node pairs whose pairing success times are equal to the total sampling times from the initial pairing success matrix to form the target pairing matrix based on the node pairs, wherein the node pairs are nodes located on the same line segment. Specifically, first, for each sampling time, the current values of each node in the initial node set at the time are extracted, and the current value of each node is compared with the current values of other nodes one by one; then, if the current values of two nodes are the same, it is determined that the two nodes are successfully paired at the current sampling time, and the two nodes are nodes on the same line segment, and this pairing is recorded in the initial pairing success matrix - the first row of the matrix records the node with the smaller number in this pairing, the second row records the node with the larger number, and the value at the corresponding position of the third row is incremented by 1 (the initial value is 0, and the count is accumulated each time a pairing is successfully completed), to record the node pairs that are successfully paired and the number of times they are successfully paired at each sampling time, to obtain an initial pairing success matrix, Then, after traversing all sampling times and completing the current value comparison and pairing record of all nodes, the third row data of the initial pairing success matrix P1 is checked to filter out the columns whose third row values are equal to the total sampling time m, and the node pairs corresponding to these columns are node pairs that are successfully paired at all sampling times (representing nodes located on the same line segment), and finally, these node pairs are sorted and summarized to form a target pairing matrix

[0072] In this way, the target pairing matrix is generated by comparing the current values of each node at the same time, which can accurately identify the nodes located on the same line segment, effectively exclude accidental pairing caused by current fluctuations or measurement errors, and ensure that only the node pair with the same current value at all sampling times is identified as the node on the same line segment, thereby significantly improving the accuracy of identifying the topological relationship in the single power non-loop radial network.

[0073] In some embodiments, the initial node set and the initial current data set are simplified according to the target pairing matrix to obtain a simplified node set and a simplified current data set after removing redundant nodes, specifically: identifying the second node in each node pair recorded in the target pairing matrix as the redundant node; assigning the positions corresponding to all the redundant nodes in the initial node set to 0, and retaining the original numbers of the non-redundant nodes to obtain the simplified node set; assigning the current data of all sampling times corresponding to the redundant nodes in the initial current data set to 0, and retaining the current data corresponding to the non-redundant nodes to obtain the simplified current data set. Specifically, first, identify the second node in each group of node pairs in the target pairing matrix P2, and define these nodes as redundant nodes; then, find the positions of these redundant nodes in the initial node set N1, and assign the node numbers of the corresponding positions to 0. The positions of the nodes in the initial node set N1 that are not marked as redundant nodes retain the original node numbers. Through the above operation, the simplified node set N2 = [1 0 3 0 5…k…n] is obtained. Then, in the initial current data set, locate all data positions corresponding to the redundant nodes (i.e., the nodes assigned to 0) in the simplified node set; assign the current data of each sampling time at these positions to 0, while the current data corresponding to the non-redundant nodes (nodes not assigned to 0) in the initial current data set I1 remain the original collected values, thereby obtaining the simplified current data set I2 = [I1 0 I3 0 I5…k…n].

[0074] It should be noted that the simplification principle is that the current values of all deleted nodes (i.e., redundant nodes) are assigned to 0.

[0075] In this way, the redundant information in the network can be effectively removed, making the simplified node set and current data set more concise and clear, reducing unnecessary interference factors, and making the subsequent topological relationship identification process more efficient and accurate.

[0076] In some embodiments, the power supply node and the initial end node set are identified from the simplified current data set, specifically: the current values of each node at all sampling times are obtained by traversing the simplified current data set; the current values of all nodes at each sampling time are compared, and the node whose current value is the maximum among all nodes at each sampling time is determined as the power supply node, and the two nodes whose current values are the minimum among all nodes at each sampling time are combined to form the initial end node set. Specifically, first, the current values of each node at all sampling times are extracted by traversing the simplified current data set I2; then, for each sampling time, the current values of all nodes at this time are compared, and the node with the maximum current value at this time is marked; then, after traversing all sampling times, the node whose current value is the maximum among all nodes at each sampling time is filtered out, and this node is determined as the power supply node N3, for example, N3 = [1]. Moreover, the current values of each node at all sampling times are obtained by traversing the simplified current data set I2, for each sampling time, the current values of all nodes at this time are compared, and the nodes with the minimum current value at this time are marked, after traversing all sampling times, the two nodes whose current values are the minimum among all nodes at each sampling time are filtered out, and these two nodes are combined to form the initial end node set N4, for example, N4 = [18 19].

[0077] In this way, the positions of the power supply node and the end node can be determined, and accurate reference points are provided for subsequent topological relationship identification.

[0078] In step S103, iterative topological identification is performed starting from the initial end node set, in each iteration, the current values of all nodes in the initial end node set are combined and added to generate a plurality of candidate parent node current values, and each candidate parent node current value is matched with the current values of all nodes in the simplified current data set at all sampling times, if the current value of a node is consistent with a candidate parent node current value at all sampling times, a parent-child connection relationship between the corresponding node in the initial end node set and the node is established, until the parent-child connection relationship of all nodes in the simplified node set is identified, the parent-child connection relationship corresponding to the simplified node is restored according to the target pairing node set, and a complete single-power non-loop radial main line topological structure is obtained.

[0079] In some embodiments, iterative topological identification is performed starting from the initial end node set, in each iteration, the current values of all nodes in the initial end node set are combined and added, specifically, in each iteration of the iterative topological identification, the current data of the nodes in the initial end node set N4 at each sampling time is extracted to perform full combination operation on the current values of these nodes.

[0080] In some embodiments, the full combination of the current values of all nodes in the initial set of end nodes generates several candidate parent node current values, specifically: combination selection is performed on all nodes in the initial set of end nodes, wherein each selection contains at least two nodes; for each node combination, the current values of the nodes at the same sampling time are added respectively to obtain a first current sum of the node combination at the sampling time; all sampling times are traversed to obtain a second current sum of the node combination at all sampling times, to determine the current value of the candidate parent node at the corresponding sampling time based on the second current sum, to form several candidate parent node current values. Specifically, first, all node combinations containing at least two nodes (i.e., combinations of 2, 3, …, and all nodes, covering all combination possibilities of “node number ≥ 2”, and the full combination number is g) in the initial set of end nodes N4 are generated; then, for each generated node combination, the current values of each node in the combination at the same sampling time are extracted, and these current values are added to obtain the first current sum of the node combination at the sampling time; then, all sampling times (from the first to the last sampling time) are traversed, and for the same node combination, the first current sum at each time is repeatedly calculated, and the first current sums at these times are summarized to form the second current sum of the node combination at all sampling times (i.e., a sequence composed of the sum values at each time) that is the end node current sum matrix Since the parent node current in the single power source loop-free topology is equal to the sum of the downstream child node currents, the sum values in the last column of the matrix (i.e., the candidate parent node current values) are extracted to determine several groups of candidate parent node current values. For example, Figure 2 , the first several groups of candidate parent node current values I 3d = [0…0I 18,d I 19,d 0…0I ∑1d ] are obtained, assuming that N2 is an n×1 matrix, then I 3d is (n+1)×g, the last column is the sum of the current of each node on the left, and the rest of the nodes are all 0.

[0081] In this way, by full combination of the current values of all nodes in the initial set of end nodes, several candidate parent node current values are generated, which can more comprehensively consider the current relationship between nodes and more accurately reflect the connection relationship between nodes, thereby improving the identification accuracy of the topology relationship.

[0082] In some embodiments, each of the candidate parent node current values is matched with the current values of all nodes in the simplified current data set at all sampling time points. Specifically, first, each of the candidate parent node current values is compared with the current values of all nodes at the corresponding sampling time point in the simplified current data set I2.

[0083] In some embodiments, the parent-child connection relationship of the corresponding node in the initial end node set is established, specifically: an initial identification matrix is constructed, wherein the rows of the initial identification matrix correspond to the nodes in the simplified node set one by one, and each row includes the node number and the parent node number of the corresponding node, and the initial value of the parent node number is 0, indicating that the node is not identified; when a certain candidate parent node current value is consistent with the current value of a certain node in the simplified current data set at all sampling time points, the parent node numbers of all end nodes participating in the generation of the candidate parent node current value are updated to the number of the consistent node; if there are still unidentified nodes in the initial identification matrix after one iteration is completed, the current values of the unidentified nodes at each sampling time point are extracted from the simplified current data set, the node with the smallest current value is added to the end node set, and the current full combination addition and consistency matching are performed again until the parent node numbers of all nodes in the initial identification matrix are not 0; the initial identification matrix is perfected according to the node pairs recorded in the target pairing matrix to obtain a parent-child connection relationship matrix representing the complete topology structure. Specifically, first, an initial identification matrix N 5d is constructed, wherein the rows of the matrix correspond to the nodes in the simplified node set one by one, and each row records the node number and the parent node number (the parent node number of 0 indicates that the node is not identified) with the initial value of 0. Then, the current values of the current end node set I 3d are full-combined and added to generate candidate parent node current values, and each candidate parent node current value is compared with the current values of all nodes at all sampling time points in the simplified current data set I2; if a certain candidate parent node current value is consistent with the current value of a certain node at all sampling time points, the parent node numbers of all end nodes participating in the generation of the candidate parent node current value are updated to the number of the consistent node in the initial identification matrix. Then, if there are still unidentified nodes with the parent node number of 0 in the initial identification matrix N 5d after one iteration (the combination addition, matching and matrix updating of the current end node set are completed), the current values of the unidentified nodes at each sampling time point are extracted from the simplified current data set I2, and the node with the smallest current value is selected and added to the end node set I 3dThen, the current full set is added again to the updated final node set to generate a new candidate parent node current value, and consistency matching is performed again with the simplified current data set I2, and the above "updating the initial identification matrix" operation is repeated until all nodes in the initial identification matrix have parent node numbers that are non-zero values (i.e., the first row value and the second row value). When the first row value and the second row value are non-zero values, it is indicated that the identification of all nodes in the simplified node data set N2 is completed. In this example, the N6 example obtained after the first identification is as follows Finally, the initial identification matrix N 5d is updated through iteration, and a preliminary parent-child connection relationship matrix N6 is obtained.

[0084] It should be noted that, for the initial identification matrix N Figure 2 obtained for the first time, the initial identification matrix N 5d is an n×2 matrix, the first row element of which is the value of N2, and the second row element of which is the number of the upper level node of the identified node. The initial values of both are assigned as 0, indicating that they are not identified. In the initial identification matrix N 5d , the node numbers corresponding to all non-zero currents except the last column in I 3d are taken, and the node numbers corresponding to the equal values of I2 at the dth moment are filled in the second row of the corresponding column of N 5d . The second row with a value indicates that it is an identified node. In this example, the N 5d example obtained after the first identification is as follows

[0085] It should be noted that the values in the second row of the same node in the initial identification matrix N 5d at all moments are counted, and the number of times of the same value in the second row is m, which is the parent node of the first row node. The first row node is an identified node. The parent-child connection relationship matrix N6 is an n×2 matrix, the first row element of which is the value of the simplified node data set N2, and the second row element of which is the number of the upper level node of the identified node. The initial values of both are assigned as 0, indicating that they are not identified. In the parent-child connection relationship matrix N6, the values in the second row of the initial identification matrix N 5d are filled in the second row of the corresponding column of the parent-child connection relationship matrix N6, indicating that the node is an identified node. In this example, the N 6d example obtained after the first identification is as follows

[0086] Thus, by constructing the initial identification matrix and gradually updating the parent-child connection relationship of the nodes, the misjudgment caused by current value fluctuation or node current similarity is effectively avoided, and the accuracy of the topological relationship identification is significantly improved, thereby providing more reliable data support for the management and optimization of the low-voltage distribution network.

[0087] In some embodiments, the initial identification matrix is perfected to obtain a parent-child connection relationship matrix representing a complete topological structure, specifically: the node number in the initial identification matrix that is assigned as 0 due to simplification is restored to the actual number of the corresponding redundant node recorded in the target pairing matrix, and the parent node number of the newly restored node is set as the number of the smaller pairing node corresponding in the target pairing matrix, to obtain a first result; for the power supply node, the parent node number is maintained as 0 to obtain a second result, and a parent-child connection relationship matrix representing a complete topological structure is determined based on the first result and the second result. Specifically, first, the positions of the nodes in the parent-child connection relationship matrix N6 that are assigned as 0 due to the simplification operation (marking the redundant nodes according to the target pairing matrix) are found, and the node numbers at these positions are replaced with the actual numbers of the corresponding redundant nodes recorded in the target pairing matrix P2; then, in the target pairing matrix P2, the smaller node paired with the newly restored node is found, and the number of the smaller node is set as the parent node number of the newly restored node to obtain a first result. At the same time, for the identified power supply node N3, the parent node number is maintained as 0 to obtain a second result. Finally, the first result and the second result are fused to determine the parent-child connection relationship between the nodes, and a parent-child connection relationship matrix N6 representing a complete single-power-supply non-loop radial main line topological structure is constructed.

[0088] It should be noted that the element in the first row of the parent-child connection relationship matrix N6 is updated to the corresponding node, and the value in the second row of the corresponding node is taken as the pairing node in the target pairing matrix P2. If the power supply node N3 has no parent node, the number of power supply nodes in the low-voltage distribution network is generally not more than 2. In this example, the N6 example obtained after the final identification is as follows:

[0089] Thus, by perfecting the initial identification matrix to obtain a complete parent-child connection relationship matrix, the accuracy of the topological relationship identification can be significantly improved, thereby improving the accuracy of identifying the topological relationship in a single-power-supply non-loop radial network.

[0090] In some embodiments, after the consistency matching of each of the candidate parent node current values with the current values of all nodes in the simplified current data set at all sampling time points, if there is no current value of a node consistent with a candidate parent node current value at all sampling time points, the node with the smallest current value in the current unidentified node is added to the final node set, and the next iteration is performed based on the updated final node set. Specifically, if no two-by-two equal condition is found (i.e., no node current is consistent with the candidate parent node current at the time), (i.e., at a certain sampling time, no node current value is consistent with the candidate parent node current value), the final node supplement process is triggered: first, from the simplified node set N2, the unidentified nodes that have not established a parent-child connection relationship are screened, and the current data of these nodes is extracted; then the extracted current data is sorted in ascending order, the node with the smallest current value is selected, and it is added to the current final node set N4, thereby updating the final node range to provide a new calculation basis for the "final node current full combination and addition, parent node matching" step of the next iteration. For example, after the first addition of a new node, the N4 example obtained in this example is N4 = [18 19 20].

[0091] In this way, by dynamically adjusting the final node set, the actual topology of the network can be more accurately reflected, especially in complex networks, which can effectively avoid identification errors caused by the unobvious characteristics of part of the node current, thereby significantly improving the accuracy and reliability of topology identification.

[0092] The embodiment of the application can reflect the current change of each node in the low-voltage distribution network, avoid topology identification error caused by subsequent data loss or inaccuracy, generate a target pairing matrix by comparing the current values at the same time, quickly identify the nodes on the same line section, eliminate the redundant nodes by simplifying the initial node set and the initial current data set, reduce the data amount of subsequent calculation, avoid the interference of the redundant nodes on the topology identification process, make the identification of the power supply node and the initial end node set more accurate, gradually establish the parent-child connection relationship by iteration, avoid error caused by processing a large amount of data at one time, ensure that the establishment of each connection relationship is accurate and reliable, finally realize the accurate identification of the parent-child connection relationship of all nodes in the simplified node set, greatly improve the accuracy of the topology relationship identification in the single-power-supply non-loop radial network, restore the position and connection relationship of the simplified nodes in the topology structure, ensure that the finally obtained topology structure is complete and accurate, realize the accurate identification of the topology relationship in the single-power-supply non-loop radial network, and provide accurate topology data support for the management and operation of the low-voltage distribution network. Compared with the prior art, the application can improve the accuracy of identifying the topology relationship in the single-power-supply non-loop radial network.

[0093] As shown in the above method embodiment, corresponding device embodiments are provided; Figure 3

[0094] An embodiment of the application provides a single-power-supply non-loop radial main line topology identification device, which comprises an acquisition module 100, a processing module 200 and an identification module 300.

[0095] The acquisition module 100 is used for acquiring the current data collected by each monitoring terminal installed on the main line of the low-voltage distribution network at different times, and constructing an initial node set and an initial current data set based on the current data.

[0096] The processing module 200 is used for comparing the current values of each node in the initial node set at the same time in pairs to generate a target pairing matrix, simplifying the initial node set and the initial current data set according to the target pairing matrix, obtaining a simplified node set and a simplified current data set after eliminating the redundant nodes, and identifying a power supply node and an initial end node set from the simplified current data set.

[0097] ​The identification module 300 is configured to perform iterative topology identification starting from the initial end node set, in each iteration, to perform full combination summation on current values of all nodes in the initial end node set, to generate a plurality of candidate parent node current values, and to perform consistency matching between each candidate parent node current value and current values of all nodes in the simplified current data set at all sampling time points, if current values of a certain node and a certain candidate parent node current value are consistent at all sampling time points, to establish a parent-child connection relationship for the corresponding node in the initial end node set and the node, until parent-child connection relationships for all nodes in the simplified node set are identified, to restore the parent-child connection relationship corresponding to the simplified node according to the target pairing node set, and to obtain a complete single-power non-loop radial main line topology structure.

[0098] It can be understood that the above-mentioned device embodiment is corresponding to the method embodiment of the present application, and can realize the single-power non-loop radial main line topology identification method provided by any one of the method embodiments of the present application.

[0099] It should be noted that the device embodiments described above are only schematic, and part or all of the modules can be selected to achieve the purpose of the present embodiment scheme according to actual needs. In addition, in the device embodiment provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, which can be realized as one or more communication buses or signal lines. Those skilled in the art can understand and implement it without creating labor.

[0100] Please refer to Figure 4 On the basis of the above-mentioned embodiment of the single-power non-loop radial main line topology identification method, another embodiment of the present application provides a topology identification system, comprising: a panel box comprising at least one sub-monitoring terminal;

[0101] Branches, comprising at least one group of branch box devices or one branch node, and being installed with at least three sub-monitoring terminals;

[0102] Transformer, comprising a transformer and a total monitoring terminal on the low-voltage side of the transformer, the total monitoring terminal and each sub-monitoring terminal are installed on the main line, and one sub-monitoring terminal is installed on each phase line for collecting current data, the total monitoring terminal is used to receive current data sent by all sub-monitoring terminals, and perform steps of the single-power non-loop radial main line topology identification method as described in the present application.

[0103] The above-mentioned is the preferred embodiment of the present application, it should be pointed out that, for those skilled in the art, without departing from the principle of the present application, a number of improvements and refinements can be made, these improvements and refinements are also considered as the protection scope of the present application.

Claims

1. A method for identifying a single-source, loop-free radial principal topology, characterized in that, include: Acquire current data collected at different times by each monitoring terminal installed on the main line of the low-voltage distribution network, and construct an initial node set and an initial current dataset based on the current data; The current values ​​of each node in the initial node set at the same time are compared pairwise to generate a target pairing matrix. The initial node set and the initial current dataset are simplified according to the target pairing matrix to obtain a simplified node set and a simplified current dataset after removing redundant nodes. The power supply node and the initial final-stage node set are identified from the simplified current dataset. Starting with the initial set of final nodes, iterative topology identification is performed. In each iteration, the current values ​​of all nodes in the initial set of final nodes are summed to generate several candidate parent node current values. The current values ​​of each candidate parent node are matched with the current values ​​of all nodes in the simplified current dataset at all sampling times. If the current value of a node is consistent with the current value of a candidate parent node at all sampling times, a parent-child connection relationship is established between the corresponding node in the initial set of final nodes and that node. This process continues until parent-child connections are identified for all nodes in the simplified node set. Based on the target paired node set, the parent-child connection relationships corresponding to the simplified nodes are restored to obtain a complete single-source acyclic radial mainline topology.

2. The single-source acyclic radial principal topology identification method according to claim 1, characterized in that, The step of comparing the current values ​​of each node in the initial node set at the same time in pairs to generate the target pairing matrix is ​​as follows: For each sampling time, the current value of each node in the initial node set is compared with that of other nodes; If the current values ​​of two nodes are the same at the sampling time, the two nodes are recorded as successfully paired at that time, and this pairing is recorded in the initial pairing success matrix. The initial pairing success matrix is ​​used to record the successfully paired node pairs and the total number of times they are successfully paired in all sampling times. Traverse all sampling times to filter out all node pairs whose number of successful pairings equals the total number of samplings from the initial successful pairing matrix, and construct the target pairing matrix based on the node pairs, wherein the node pairs are nodes located on the same line segment.

3. The single-source acyclic radial principal topology identification method according to claim 1, characterized in that, The initial node set and the initial current dataset are simplified according to the target pairing matrix to obtain a simplified node set and a simplified current dataset after removing redundant nodes. Specifically: The second node in each node pair recorded in the target pairing matrix is ​​identified as the redundant node; The positions corresponding to all redundant nodes in the initial node set are assigned the value 0, and the original numbers of the non-redundant nodes are retained to obtain the simplified node set. The current data at all sampling times corresponding to the redundant nodes in the initial current dataset are assigned a value of 0, while the current data corresponding to the non-redundant nodes are retained to obtain the simplified current dataset.

4. The single-source acyclic radial principal topology identification method according to claim 1, characterized in that, The process of identifying the power supply nodes and the initial set of final-stage nodes from the simplified current dataset specifically involves: The simplified current dataset is traversed to obtain the current value of each node at all sampling times; By comparing the current values ​​of all nodes at each sampling time, the node whose current value is the largest among all nodes at each sampling time is determined as the power supply node, and the two nodes whose current values ​​are the smallest among all nodes at each sampling time are formed into the initial final-level node set.

5. The single-source acyclic radial principal topology identification method according to claim 1, characterized in that, The step of combining and summing the current values ​​of all nodes in the initial final-level node set to generate several candidate parent node current values ​​is as follows: All nodes in the initial final-level node set are selected in combination, wherein each selection includes at least two nodes; For each node combination, the current values ​​of the node combination at the same sampling time are added together to obtain the first sum of the currents of the node combination at that sampling time; By iterating through all sampling times, the second current sum of the node combination at all sampling times is obtained, and the current value of the candidate parent node at the corresponding sampling time is determined based on the second current sum, so as to form a number of candidate parent node current values.

6. The single-source acyclic radial principal topology identification method according to claim 1, characterized in that, After performing consistency matching between the current values ​​of each candidate parent node and the current values ​​of all nodes in the simplified current dataset at all sampling times, the method further includes: If there is no node whose current value is consistent with the current value of a candidate parent node at all sampling times, then the node with the smallest current value among the currently unidentified nodes is added to the last-level node set, and the next iteration is performed based on the updated last-level node set.

7. The single-source acyclic radial principal topology identification method according to claim 1, characterized in that, The step of establishing a parent-child connection between the corresponding node in the initial set of final-level nodes and the node itself is specifically as follows: Construct an initial identification matrix, wherein each row of the initial identification matrix corresponds one-to-one with a node in the simplified node set, and each row includes a node number and its corresponding parent node number, with the initial value of the parent node number being 0 to indicate that it is not identified. When the current value of a candidate parent node is consistent with the current value of a node in the simplified current dataset at all sampling times, the parent node numbers of all final-level nodes that participate in constituting the current value of the candidate parent node are updated to the number of the consistent node. If there are still unidentified nodes in the initial identification matrix after one iteration, the current values ​​of the unidentified nodes at each sampling time are extracted from the simplified current dataset, and the node with the smallest current value is added to the final node set. The current full combination summation and consistency matching are performed again until the parent node number of all nodes in the initial identification matrix is ​​not 0. Based on the node pairs recorded in the target pairing matrix, the initial identification matrix is ​​improved to obtain a parent-child connection matrix representing the complete topology.

8. The single-source acyclic radial principal topology identification method according to claim 7, characterized in that, The process of refining the initial identification matrix to obtain a parent-child connection matrix representing the complete topological structure is as follows: The node numbers in the initial identification matrix that were assigned a value of 0 due to simplification are restored to the actual numbers of the corresponding redundant nodes recorded in the target pairing matrix. The parent node number of the newly restored node is set to the number of the pairing node with the smaller number in the target pairing matrix to obtain the first result. For a power node, keep its parent node number 0 to obtain a second result, and determine the parent-child connection matrix representing the complete topology based on the first result and the second result.

9. A single-powered, loop-free radial principal topology identification device, characterized in that, include: The module consists of an acquisition module, a processing module, and an identification module. The acquisition module is used to acquire current data collected at different times by each monitoring terminal installed on the main line of the low-voltage distribution network, and to construct an initial node set and an initial current dataset based on the current data. The processing module is used to compare the current values ​​of each node in the initial node set at the same time in pairs to generate a target pairing matrix. Based on the target pairing matrix, the initial node set and the initial current dataset are simplified to obtain a simplified node set and a simplified current dataset after removing redundant nodes. The power supply node and the initial final-stage node set are identified from the simplified current dataset. The identification module is used to perform iterative topology identification starting from the initial final-level node set. In each iteration, the current values ​​of all nodes in the initial final-level node set are summed to generate several candidate parent node current values. The current values ​​of each candidate parent node are matched with the current values ​​of all nodes in the simplified current dataset at all sampling times. If the current value of a node is consistent with the current value of a candidate parent node at all sampling times, a parent-child connection relationship is established between the corresponding node in the initial final-level node set and the node. This process continues until the parent-child connection relationship is identified for all nodes in the simplified node set. Based on the target paired node set, the parent-child connection relationship corresponding to the simplified node is restored to obtain a complete single-source acyclic radial mainline topology.

10. A topology identification system, characterized in that, include: The meter box includes at least one sub-monitoring terminal; A branch includes at least one set of branch box equipment or one branch node, and is equipped with at least three sub-monitoring terminals; The transformer includes a transformer and a main monitoring terminal on the low-voltage side of the transformer. The main monitoring terminal and each of the sub-monitoring terminals are installed on the main line, and one sub-monitoring terminal is installed on each phase line for collecting current data. The main monitoring terminal is used to receive the current data sent by all sub-monitoring terminals and perform the steps of the single-source loopless radial main line topology identification method as described in any one of claims 1 to 8.

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