A phase identification method for low voltage substations

Abstract

The present invention discloses a low-voltage substation phase identification method, comprising the following steps: S1, collecting address information and historical voltage sequence data of all users in the substation to be identified; S2, determining the phase to which the user belongs based on the user's address information and / or historical voltage sequence, including: phase A, phase B and phase C; S3, determining the meter box to which the user belongs in phase A, phase B and phase C; S4, comparing the meter box and phase to which each user belongs with the records in the substation archives, if they are consistent, marking the recorded information of the user in the substation archives as credible, otherwise marking the recorded information of the user in the substation archives as untrustworthy. The present invention improves the phase recognition rate based on voltage sequence and address information, makes full use of existing information to help with identification, can accurately identify the phase ownership problem of users in the low-voltage substation, reduces the burden on the operation and maintenance personnel of the low-voltage distribution network substation, and improves the overall work efficiency.

Description

Technical Field

[0001] The present invention belongs to the field of electric power technology, and more specifically, the present invention relates to a low-voltage substation phase identification method. Background Art

[0002] The low-voltage distribution network topology model clearly defines the phase connection relationship between each user and the distribution transformer within a substation. An accurate distribution network topology model is crucial for ensuring the safe and stable operation of the distribution system. It serves as the foundation for applications such as line loss analysis, three-phase balancing, and power theft analysis within the substation, improving the reliability of the substation's power supply. When a substation requires a regional power outage due to maintenance or a fault, the substation topology model can be used to notify each user within the outage area in advance, allowing them to prepare for the outage and improving their electricity experience. Users in older residential communities may have privately installed wiring, resulting in line changes. Alternatively, the line information of newly added users may not be updated in the substation archives in a timely manner, leading to discrepancies between the substation archives and actual line information. This makes it difficult to accurately notify users in the event of a power outage in the corresponding area. Therefore, distribution network substation operations and maintenance personnel are required to regularly review the information recorded in the substation archives to ensure that the substation archives are updated. Manual verification of substation archive information is inefficient. Summary of the Invention

[0003] The present invention provides a low voltage phase identification method, aiming to improve the above-mentioned problem.

[0004] The present invention is implemented in this way, a low-voltage phase identification method, the method specifically comprising the following steps:

[0005] S1. Collect the address information and historical voltage sequence data of all users in the area to be identified;

[0006] S2. Determine the phase to which the user belongs based on the user's address information and / or historical voltage sequence, including: phase A, phase B, and phase C;

[0007] S3. Determine the meter boxes to which the users in phases A, B, and C belong;

[0008] S4. Compare the meter boxes and phases belonging to each user with the records in the district archives. If they are consistent, the record information of the user in the district archives is marked as credible. Otherwise, the record information of the user in the district archives is marked as untrustworthy.

[0009] Furthermore, the method for determining the phase to which a user belongs based on the historical voltage sequence is as follows:

[0010] The Pearson voltage correlation coefficient r between each user is calculated. Based on the judgment threshold β of the correlation coefficient, the users are divided into three categories. The Pearson voltage correlation coefficient r between two users of the same category is greater than the judgment threshold β of the correlation coefficient.

[0011] Furthermore, the method for determining the phase to which a user belongs based on address information is as follows:

[0012] The building, unit, and room number to which the user belongs are encoded with a standard length, and a numerical sequence is formed in sequence according to the building, unit, and room number. The users are divided into three categories based on the clustering algorithm, and the phases to which the three categories of users belong are determined based on the voltage change trends of each category of users.

[0013] Furthermore, the method for determining the phase to which a user belongs based on address information and historical voltage sequence is as follows:

[0014] Determine the phase to which the user belongs based on address information and historical voltage sequence;

[0015] When the output results of the two methods are consistent, the judgment result is deemed accurate. If the output results of the two methods are inconsistent, the user will be marked, and the marked user will not participate in the subsequent process.

[0016] Furthermore, the step S3 specifically includes the following steps:

[0017] Perform the first clustering of users based on historical voltage series and assign them to various distribution boxes;

[0018] Secondary clustering is then performed based on user address information to assign users to the wire boxes under each distribution junction box.

[0019] Furthermore, the method for determining the meter box to which the user belongs in phase A, phase B and phase C is as follows:

[0020] Based on the clustering method, the users in phase A are divided into M d clusters, k d ≥M d ≥M D , where M D is the number of distribution boxes in the area to be identified, k d is the number of meter boxes in the area to be identified;

[0021] Count the number of users belonging to each unit in each cluster, traverse each unit in turn, identify the cluster with the largest number of users as the cluster where the corresponding unit is located, define the total number of line boxes of all units in each cluster as the number of clusters for the next clustering, perform a second clustering on each cluster, obtain sub-clusters within each cluster, identify users in the same sub-cluster as users belonging to the same meter box, classify users based on the meter box where each user address in the sub-cluster is located, count the number of users under each meter box, and assign the sub-cluster to the meter box with the largest number of users.

[0022] The present invention improves the phase recognition rate based on voltage sequence and address information, makes full use of existing information to help identification, and can automatically identify the phase of low-voltage users and meter box ownership issues in the low-voltage distribution network area, reducing the burden on low-voltage distribution network area operation and maintenance personnel and improving overall work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flow chart of a low-voltage phase identification method provided by an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of user classification based on the Pearson voltage correlation coefficient r provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The specific implementation methods of the present invention will be further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0026] Figure 1 A flow chart of a low-voltage phase identification method provided in an embodiment of the present invention, the method specifically includes the following steps:

[0027] S1. Collect the address information and historical voltage sequence data of all users in the area to be identified;

[0028] The substation area in the present invention refers to the power supply area of ​​a transformer. Generally, one transformer supplies power to one community. In the embodiment of the present invention, if the voltage value of a user at a certain moment is missing or abnormal, the missing value is supplemented by interpolation and the abnormal value is deleted;

[0029] Since address information has an inconsistent format, key data is extracted and inserted into a standard template to form address information in a standard format. The key data here include: community name, building number (building) and unit number (room).

[0030] S2. Determine the phase to which the user belongs based on the user's address information and / or historical voltage sequence, including: phase A, phase B, and phase C;

[0031] The voltage sequence is a sequence of voltage values ​​in a time series, reflecting the change of voltage over time. The time points in the historical voltage series of different users must be the same. Different acquisition devices have different acquisition frequencies, which may result in different time points in the voltage series of different users. In this case, the voltage value sequence of each user in the same time series is obtained through interpolation.

[0032] In an embodiment of the present invention, the method for determining the phase to which a user belongs based on the historical voltage sequence is specifically as follows:

[0033] The Pearson voltage correlation coefficient r between two users is calculated. Based on the judgment threshold β of the correlation coefficient, the users are divided into three categories. The Pearson voltage correlation coefficient r between two users of the same category is greater than the judgment threshold β of the correlation coefficient, such as Figure 2 As shown, the correlation coefficient determination threshold β=0.92, users m1 to m10 are divided into three categories, users m2 to m5 are in one category, users m6 to m8 are in one category, and users m9, m10, and m1 are in one category; then, the phases to which the three categories of users belong are determined based on the voltage change trend of each category of users.

[0034] In an embodiment of the present invention, the method for determining all phases based on the voltage change trend of each type of user is as follows:

[0035] The voltage variation curves (voltage-time curves) of the three types of users and the voltage variation curves (voltage-time curves) of the three-phase UVW (ABC) under the transformer are drawn. The image curves within a time period are randomly intercepted and the curves of the three types of users are compared with the curves of the three phases of the transformer. If the curves of one type of user and one phase of the transformer curve (assuming it is U / A phase) have the same power consumption characteristics within the time period, that is, a certain family of curves on the curve and a certain phase curve of the transformer have the same trend (rise, fall, peak, concave and convex, etc.), while the other two types do not, then they are determined to be the same phase (such as phase A). Otherwise, reselect the time period to search, and the discrimination method for the other two phases is the same.

[0036] In an embodiment of the present invention, a method for determining a phase to which a user belongs based on address information is specifically as follows:

[0037] The building, unit, and room numbers of the users are encoded with a standard length and then organized into a numerical sequence according to the building, unit, and room numbers. The users are divided into three categories based on the k-means clustering algorithm. The phases of the three categories of users are then determined based on the voltage change trends of each category of users.

[0038] In an embodiment of the present invention, a method for determining the phase to which a user belongs based on address information and historical voltage sequences is specifically as follows:

[0039] The phase to which the user belongs is determined based on the address information and the historical voltage sequence respectively. The phase determination method for the user based on the address information and the phase determination method for the user based on the historical voltage sequence are as described above.

[0040] When the output results of the above two methods are consistent, the output is performed directly. If the output results of the two methods are inconsistent, the user will be marked. The marked user will not participate in the subsequent process and needs to be manually reviewed.

[0041] S3. Determine the meter boxes to which the users in phases A, B, and C belong;

[0042] In an embodiment of the present invention, there are one or more distribution junction boxes in the to-be-identified substation, and each distribution junction box has multiple meter boxes under it. There is at least one meter box in a unit, and each meter box has multiple users of phases A, B, and C. First, the users are clustered based on the historical voltage sequence and assigned to each distribution junction box. Based on the first clustering, a second clustering is performed based on the user address information, and the users are assigned to the wire boxes under each distribution junction box. The specific determination method is as follows:

[0043] Based on the clustering method, the users in phase A are divided into M d clusters, k d ≥M d ≥M D , where M D is the number of distribution boxes in the area to be identified, k d is the number of meter boxes in the area to be identified;

[0044] Count the number of users belonging to each unit in each cluster. The same units in different buildings belong to different units. Traverse each unit in turn and identify the cluster with the largest number of users as the cluster where the corresponding unit is located. Define the total number of line boxes of all units in each cluster as the number of clusters for the next clustering. Perform a second clustering on each cluster to obtain sub-clusters within each cluster. Identify users in the same sub-cluster as users belonging to the same meter box. Classify users based on the meter box where the addresses of each user in the sub-cluster are located. Count the number of users under each meter box and assign the sub-cluster to the meter box with the largest number of users.

[0045] Assume that there are a large number of 4-unit and 5-unit users and a small number of 6-unit users in cluster 1, and a large number of 6-unit and 7-unit users in cluster 2. Among them, there are 2 wire boxes in 4-unit, and there is only one wire box in 5-unit, 6-unit and 7-unit. Then the number of clusters in the next clustering of cluster 1 is 1*2+1=3, that is, cluster 1 is divided into 3 sub-clusters, and the number of clusters in the next clustering of cluster 2 is 2, that is, cluster 2 is divided into 2 sub-clusters.

[0046] In the embodiment of the present invention, the method for determining the meter box to which users in phases B and C belong is the same as the method for determining the meter box to which users in phase A belong, and is not described in detail here.

[0047] S4. Compare the meter box and phase of each user with the records in the substation archive. If they match, the user's record information in the substation archive is marked as credible. Otherwise, the user's record information in the substation archive is marked as untrustworthy. For ease of output display, credible users are marked in green, and untrustworthy users are marked in red.

[0048] The substation files record the user's transformer, distribution junction box, meter box and their phases.

[0049] The present invention has been described exemplarily. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A low voltage phase identification method, characterized in that: The method specifically comprises the following steps: S1. Collect the address information and historical voltage sequence data of all users in the area to be identified; S2. Determine the phase to which the user belongs based on the user's address information and / or historical voltage sequence, including: phase A, phase B, and phase C; S3. Determine the meter boxes to which the users in phases A, B, and C belong; S4. Compare the meter box and phase of each user with the records in the district archive. If they are consistent, the record information of the user in the district archive is marked as credible. Otherwise, the record information of the user in the district archive is marked as untrustworthy. The method for determining the phase to which a user belongs based on address information and historical voltage sequences is as follows: Determine the phase to which the user belongs based on address information and historical voltage sequence; If the output results of the two methods are consistent, the judgment result is considered accurate. If the output results of the two methods are inconsistent, the user will be marked and the marked user will not participate in the subsequent process; The step S3 specifically includes the following steps: Perform the first clustering of users based on historical voltage series and assign them to various distribution boxes; Secondary clustering is then performed based on user address information to assign users to the wire boxes under each distribution box; The method for determining the meter box to which the users in phase A, phase B and phase C belong is as follows Based on the clustering method, the users in phase A are divided into M d clusters, k d ≥M d ≥M D , where M D is the number of distribution boxes in the area to be identified, k d is the number of meter boxes in the area to be identified; Count the number of users belonging to each unit in each cluster, traverse each unit in turn, identify the cluster with the largest number of users as the cluster where the corresponding unit is located, define the total number of line boxes of all units in each cluster as the number of clusters for the next clustering, perform a second clustering on each cluster, obtain sub-clusters within each cluster, identify users in the same sub-cluster as users belonging to the same meter box, classify users based on the meter box where each user address in the sub-cluster is located, count the number of users under each meter box, and assign the sub-cluster to the meter box with the largest number of users.

2. The low voltage phase identification method according to claim 1, characterized in that: The method for determining the phase to which a user belongs based on the historical voltage sequence is as follows: The Pearson voltage correlation coefficient r between each user is calculated. Based on the judgment threshold β of the correlation coefficient, the users are divided into three categories. The Pearson voltage correlation coefficient r between two users of the same category is greater than the judgment threshold β of the correlation coefficient.

3. The low voltage phase identification method according to claim 1, characterized in that: The method for determining the phase to which a user belongs based on address information is as follows: The building, unit, and room number to which the user belongs are encoded with a standard length, and a numerical sequence is formed in sequence according to the building, unit, and room number. The users are divided into three categories based on the clustering algorithm, and the phases to which the three categories of users belong are determined based on the voltage change trends of each category of users.

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