Physical topology identification method based on dual-mode low-voltage area

Abstract

The physical topology identification method based on a dual-mode low-voltage area includes a dual-mode module composed of a PLC and an RF device, and the physical topology identification method includes the following steps: S1, forming an area network; S2, starting topology identification, and uniformly sending messages to all RF nodes; S3, recording the RSSI value of each RF node and its one-hop relationship RF node, and forming the meter number and RSSI relationship data; S4, whether all the collection is completed, if yes, entering the next step, otherwise returning to the previous step; S5, collecting the RSSI data collected by all RF nodes, and converting the RSSI data into distance length information; S6, converting the distance matrix into a coordinate matrix; S7, adding the phase information in the PLC to obtain the physical topology; and S8, obtaining the coordinate information and line information of all RF nodes. The present application can complete the topology identification without manual intervention based on the existing dual-mode module area environment, has high identification precision, is convenient and safe, and has stronger practicability.

Description

Technical Field

[0001] This invention belongs to the field of power communication technology and relates to the improvement of the accuracy of physical topology identification in low-voltage distribution networks, specifically a physical topology identification method based on dual-mode low-voltage distribution areas. Background Technology

[0002] With the increasing coverage of my country's power grid equipment and continuous technological development, higher requirements have been placed on electricity safety and the collection of electricity data. In the early stages of low-voltage distribution network construction, the lines were not clearly planned, and the physical hierarchical relationships of lines in many areas were not clearly defined. This has had a significant impact on the calculation of line losses and energy consumption analysis of low-voltage distribution networks, and has also greatly hindered the later line renovation and optimization upgrades.

[0003] Currently available physical topology technologies mainly include the following methods:

[0004] 1. Identifying meter box topology by adding hardware. This method requires installing a meter box terminal device in each box and replacing the carrier module. For individually installed meters, the terminal data increases accordingly, essentially requiring a manual re-sorting of meter locations. The identification process also involves a continuous increase in short-circuit current, increasing the transformer load and posing a safety hazard.

[0005] 2. Calculate the topology hierarchy by line impedance. This method collects the voltage and current of all meters at the same time and judges the topology relationship based on the correlation of the calculation results. This method requires a large amount of data to be measured and analyzed, and the current and voltage are greatly affected by the environment, resulting in low accuracy.

[0006] 3. Calculate the distance between nodes by measuring latency to construct the physical topology. This method saves on the deployment of additional equipment and provides hierarchical relationships as well as distance data between nodes. However, it cannot provide the orientation of each node within the topology, and the calculation results may contain errors due to the existence of curves and loops in the lines.

[0007] For example, the "Physical Topology Discovery Method for Low-Voltage Station Power Supply Network Based on Time Delay Measurement" disclosed in Chinese Patent (Authorization Announcement No. CN110912748B) includes the following steps: Step 1, acquiring measurement data; Step 2, processing measurement information; Step 3, clustering nodes into clusters, i.e., using a clustering algorithm to cluster nodes according to time delay to form clusters; Step 4, fitting equations and solving them, i.e., adding virtual nodes to the clusters after clustering to generate tomographic equations, thereby obtaining the physical topology within the clusters by solving the equations; Step 5, generating the complete physical topology, i.e., treating each cluster in Step 4 as a node, generating tomographic equations, and obtaining the complete topology by solving the equations.

[0008] For example, Chinese patent (authorization announcement number CN113300356B) discloses "a method for identifying the topology of a low-voltage distribution transformer area." It includes the following steps: S1: Networking the distribution transformer area and obtaining the device addresses of each device;

[0009] S2: The head-end equipment synchronizes the time of all devices; S3: The head-end equipment calls out the names of the end devices and intermediate devices one by one; the intermediate devices detect the identification current signal using 2DPSK modulation in real time and record the timestamp of the detected topology identification signal; S4: The head-end equipment compares the timestamps and forms the distribution area topology step by step according to the device address of the topology identification command detected by each device. Using the 2DPSK modulated current signal as the identification signal can accurately identify the physical topology of the low-voltage distribution network and reduce the interference of large currents on the line to the power grid.

[0010] While the aforementioned disclosed technical solutions offer improvements in topology identification, they still fall short in accuracy. Furthermore, existing physical topology information only includes line and hierarchy information, lacking relative location information, which impacts the management and use of low-voltage distribution networks. Summary of the Invention

[0011] The purpose of this invention is to provide a physical topology identification method based on dual-mode low-voltage distribution areas, which solves the problems existing in the physical topology identification methods of low-voltage distribution networks.

[0012] To achieve the objectives of this invention, the following technical solution is adopted:

[0013] A physical topology identification method based on dual-mode low-voltage distribution areas includes a dual-mode module composed of a PLC and RF devices. The physical topology identification method includes the following steps:

[0014] S1 establishes a regional network;

[0015] S2 initiates topology identification and sends messages to all RF nodes in a unified manner.

[0016] S3 records the RSSI value of each RF node and its one-hop RF node, forming the data on the relationship between the meter number and RSSI.

[0017] If S4 has been fully collected, proceed to the next step; otherwise, return to the previous step.

[0018] S5 collects RSSI data from all RF nodes and converts it into distance information;

[0019] S6 converts the distance matrix into a coordinate matrix;

[0020] S7 adds phase information from the PLC to obtain the physical topology;

[0021] S8 obtains the coordinates and line information of all RF nodes.

[0022] To further achieve the objectives of this invention, the following technical solutions may also be adopted:

[0023] In the physical topology identification method based on dual-mode low-voltage substations as described above, during step S2, a message is sent to the adjacent RF node so that the receiving RF node can measure the RSSI value with the surrounding one-hop node.

[0024] In the physical topology identification method based on dual-mode low-voltage substations described above, the one-hop node refers to an adjacent RF node that can communicate directly with the RF node through the RF channel.

[0025] In the physical topology identification method based on dual-mode low-voltage distribution area described above, in step S3, each RF node records the RSSI value with other RF nodes n times, recording once each time it is started, pending collection by the master station or concentrator.

[0026] In the physical topology identification method based on dual-mode low-voltage distribution area described above, in step S5, the master station or concentrator collects RSSI data of all RF nodes, summarizes and filters n sets of data using the Laida method, and then processes the data in pairs using the median average filtering method to obtain a unique usable value. If two RF nodes are receivers for each other, the RSSI data will eventually be the same unique value.

[0027] In the physical topology identification method based on dual-mode low-voltage distribution area as described above, in step S5, RSSI data is converted into distance length information using the formula d' = 10(A - RSSI(d)) / 10m. In the formula, d' represents the estimated distance of RSSI(d) value, A represents the RSSI value at a distance of 1m from the signal transmitter, RSSI(d) represents the RSSI value at a distance of dm from the signal transmitter, and m represents the path loss index.

[0028] In the physical topology identification method based on dual-mode low-voltage distribution areas described above, the RF device is a mobile RF device. The mobile RF device is an RF meter reader / controller.

[0029] This invention is based on a State Grid dual-mode module distribution area. The default module uses an omnidirectional antenna, capable of receiving RF signals from other RF nodes in all 360 degrees, without directional limitations. There is a relationship between the RF signal received strength (RSSI) and the transmission distance. The distance between nodes can be derived from the RSSI values ​​of different RF nodes. Since RF signals are not limited by power line branches, in addition to obtaining the distances between nodes on the same line, the distances between this RF node and other branch RF nodes can also be derived. Using the three-point positioning method, the relative positions of all RF nodes in the entire distribution area can be deduced.

[0030] Compared with the prior art, the advantages of the present invention are as follows:

[0031] This invention is based on the existing dual-mode module transformer area environment, and can complete topology identification without manual intervention. It has high identification accuracy, is convenient and safe, and is more practical.

[0032] This invention utilizes the wireless communication capabilities of RF (Radio Frequency), a feature not found in existing physical topology identification methods. Combined with improvements to identification techniques, it significantly enhances performance. The topology identification results include coordinate information—the relative positions of different nodes—while existing physical topology information only provides line and hierarchy information, lacking relative positional information. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0034] Figure 1 This is a flowchart of this embodiment;

[0035] Figure 2 This is the physical topology diagram of this embodiment;

[0036] Figure 3 This is the physical topology diagram optimized by the mobile assistive device in this embodiment. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0038] In the description of the embodiments of this invention, unless otherwise explicitly limited, terms such as setting, installing, and connecting should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0039] In low-voltage distribution network operation, the State Grid has extensively deployed PLC+RF dual-mode solutions. RF has many application prospects, and wireless ranging and positioning based on RF can enrich the dimensions of the physical topology. Based on this, this invention can calculate and improve the accuracy of the physical topology hierarchy while maintaining the operating environment of the transformer area. At the same time, it can realize two-dimensional physical topology through three-point positioning, eliminating the workload of re-construction while maintaining accuracy, and ensuring safety.

[0040] like Figure 1As shown, the physical topology identification method based on dual-mode low-voltage distribution area disclosed in this embodiment includes a dual-mode module composed of a PLC and RF equipment. The physical topology identification method includes the following steps:

[0041] S1 establishes a regional network;

[0042] S2 initiates topology identification and sends messages to all RF nodes in a unified manner.

[0043] During topology identification, messages are sent to neighboring RF nodes so that the receiving RF node can measure the RSSI value with its surrounding one-hop nodes. A one-hop node refers to a neighboring RF node with which the receiving RF node can communicate directly via an RF channel.

[0044] S3 records the RSSI value of each RF node and its one-hop RF node, forming the data on the relationship between the meter number and RSSI.

[0045] Each RF node records its RSSI value with other RF nodes n times, once per startup, pending collection by the master station or concentrator.

[0046] Based on the above steps, the raw RSSI data obtained in this embodiment is shown in Table 1.

[0047] Table 1: Raw RSSI Data

[0048]

[0049] If S4 has been fully collected, proceed to the next step; otherwise, return to the previous step.

[0050] S5 collects RSSI data from all RF nodes and converts it into distance information;

[0051] The master station or concentrator collects RSSI data from all RF nodes, summarizes the data, filters the n sets of data using the Laida method, and then processes the data in pairs using the median average filtering method to obtain a unique usable value. If two RF nodes are receivers for each other, the RSSI data will eventually be the same unique value.

[0052] The RSSI data optimized by the above steps in this embodiment is shown in Table 2.

[0053] Table 1: Optimized RSSI data

[0054]

[0055] The RSSI data is converted into distance information using the formula d' = 10(A - RSSI(d)) / 10m. In the formula, d' represents the estimated distance of the RSSI(d) value, A represents the RSSI value at a distance of 1m from the signal transmitter, RSSI(d) represents the RSSI value at a distance of dm from the signal transmitter, and m represents the path loss index.

[0056] S6 converts the distance matrix into a coordinate matrix;

[0057] S7 adds phase information from the PLC; lines with the same phase belong to the same circuit, thus obtaining the physical topology. See [link to physical topology documentation] for details. Figure 2 .

[0058] S8 obtains the coordinates and line information of all RF nodes.

[0059] Since RF also has blind spots, moving the RF device can improve topology accuracy. This embodiment uses an RF meter reader for topology identification, such as... Figure 3 As shown. Figure 3 and Figure 2 Compared to the previous method, the accuracy of using RF meter readers for topology identification has been significantly improved.

[0060] All technical contents not described in detail in this invention are publicly known technologies.

Claims

1. A physical topology identification method based on dual-mode low-voltage distribution areas, comprising a dual-mode module consisting of a PLC and RF equipment, characterized in that, The physical topology identification method includes the following steps: S1 establishes a regional network; S2 initiates topology identification and sends messages to all RF nodes in a unified manner. S3 records the RSSI value of each RF node and its one-hop RF node, forming the data on the relationship between the meter number and RSSI. If S4 has been fully collected, proceed to the next step; otherwise, return to the previous step. S5 collects RSSI data from all RF nodes and converts it into distance information; S6 converts the distance matrix into a coordinate matrix; S7 adds phase information from the PLC to obtain the physical topology; S8 obtains the coordinates and line information of all RF nodes.

2. The physical topology identification method based on dual-mode low-voltage distribution areas according to claim 1, characterized in that, In step S2, during the topology identification process, a message is sent to the adjacent RF nodes so that the receiving RF nodes can measure the RSSI value with the surrounding one-hop nodes.

3. The physical topology identification method based on dual-mode low-voltage distribution areas according to claim 2, characterized in that, The first-hop node refers to the adjacent RF node that can communicate directly with the RF node through the RF channel.

4. The physical topology identification method based on dual-mode low-voltage distribution areas according to claim 1, characterized in that, In step S3, each RF node records the RSSI values ​​of other RF nodes n times, recording once each time it is started, pending collection by the master station or concentrator.

5. The physical topology identification method based on dual-mode low-voltage distribution areas according to claim 1, characterized in that, In step S5, the master station or concentrator collects RSSI data from all RF nodes, summarizes the data, filters the n sets of data using the Raida method, and then processes the data in pairs using the median average filtering method to obtain a unique usable value. If two RF nodes are receivers for each other, the RSSI data will eventually be the same unique value.

6. The physical topology identification method based on dual-mode low-voltage distribution areas according to claim 1, characterized in that, In step S5, the RSSI data is converted into distance length information using the formula d' = 10(A - RSSI(d)) / 10m. In the formula, d' represents the estimated distance of the RSSI(d) value, A represents the RSSI value when the distance to the signal transmitter is 1m, RSSI(d) represents the RSSI value when the distance to the signal transmitter is dm, and m represents the path loss index.

7. The physical topology identification method based on dual-mode low-voltage distribution areas according to claim 1, characterized in that, The RF device is a mobile RF device.

8. The physical topology identification method based on dual-mode low-voltage distribution areas according to claim 7, characterized in that, The mobile RF device is an RF meter reader.

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