A voltage curve similarity calculation method considering reference area

Abstract

The present invention provides a method for calculating the similarity of voltage curves considering a reference substation, comprising the following steps: A. obtaining substation-related data, wherein the substation-related data includes: the correspondence between 10kV lines and substations, substation names, substation address codes, and 96-point voltage data at substation outlets; B. preprocessing the data based on the 96-point voltage data at the distribution transformer outlet obtained in step A to form a substation identification matrix; C. determining a reference substation according to the substation identification matrix preprocessed in step B; D. calculating the similarity of substation voltage curves according to the reference substation determined in step C. The method for calculating the similarity of voltage curves considering a reference substation proposed in the present invention can also calculate the similarity of substation voltage curves when there is no 10kV line voltage curve, and can provide a data basis for substation line-transformer relationship verification.

Description

Technical Field

[0001] The invention relates to the technical field of distribution station area operation, and in particular to a voltage curve similarity calculation method considering a reference station area. Background Art

[0002] The line-transformer relationship of the distribution network is a very important basic data. When the line-transformer relationship is wrong, it will directly affect the line loss calculation, power outage management and the operation and maintenance of the distribution network line. In order to verify the correctness of the line-transformer relationship, the traditional manual method is used, but it is time-consuming and labor-intensive and difficult to ensure real-time performance. The operation of the distribution network will generate a large amount of operation data. By analyzing and mining this data, it can be used to carry out automatic verification of the line-transformer relationship of the distribution network.

[0003] When conducting line-transformer relationship verification in a distribution network, it is generally necessary to calculate the similarity between the substation voltage curve and the 10kV line voltage curve, but it is difficult to obtain the 10kV line voltage curve in practice.

[0004] The Chinese patent "Line-to-Transformer Relationship Identification System" with publication number CN 201911283816.9 includes a line-to-transformer relationship identification master station, a line-to-transformer relationship analysis machine, and a line-to-transformer relationship identification terminal; the line-to-transformer relationship identification master station notifies the line-to-transformer relationship identification terminal on the low-voltage side of the distribution transformer to send an ultra-low frequency carrier signal; the line-to-transformer relationship analysis machine at the head end of the substation line detects the characteristic signal; the line-to-transformer relationship analysis machine uploads the signal characteristics to the line-to-transformer relationship identification master station; the line-to-transformer relationship identification master station determines the line ownership of the transformer through comprehensive comparison. The Chinese invention patent "A Line-to-Transformer Relationship Identification Method" with publication number CN202120149670.X, the master station sends an identification command to the corresponding line-to-transformer terminal through a 4G signal; after receiving the command, the line-to-transformer terminal sends an identification signal to the 10kV power line; after receiving the power line signal, the line-to-transformer relationship analysis machine reports it to the master station through a 4G signal; the master station determines the line-to-transformer relationship through the corresponding relationship between the line-to-transformer terminal and the line-to-transformer relationship analysis machine.

[0005] Although the above patents involve the verification of the line-transformer relationship in the substation, they all require additional installation of devices to implement them, and do not involve the calculation of the similarity of the voltage curve considering the reference substation. Summary of the invention

[0006] The present invention provides a voltage curve similarity calculation method considering a reference substation, which can calculate the similarity of the substation voltage curve when there is no 10kV line voltage curve, and can provide a data basis for the verification of the substation line-transformer relationship.

[0007] The technical solution adopted by the present invention is:

[0008] A method for calculating voltage curve similarity considering a reference station area comprises the following steps:

[0009] A. Obtaining the relevant data of the substation, which includes: the correspondence between the 10kV line and the substation, the substation name, the substation address code, and the voltage data of 96 points at the substation outlet;

[0010] B. Based on the 96-point voltage data of the distribution transformer outlet obtained in step A, pre-process the data to form a substation marking matrix;

[0011] C. Determine the reference area according to the area marker matrix preprocessed in step B;

[0012] D. Calculate the similarity of the voltage curves of the reference areas determined in step C.

[0013] Furthermore, in step B, the data is preprocessed, specifically:

[0014] Assuming that a 10kV line has n substations and m days of data are collected, the substation set is recorded as:

[0015]

[0016] where a i,j represents the calculated voltage curve of the ith substation on the jth day, 1≤i≤n, 1≤j≤m, a i,j Contains 96 points of voltage data for one day, recorded as If for any All meet ≠ null value, then let area a i,j Logo of b i,j =1, otherwise let area a i,j Logo of b i,j =0;

[0017] All stations are preprocessed according to the above method to form the station mark matrix B:

[0018]

[0019] Furthermore, in step C, the reference area is determined according to the area marker matrix preprocessed in step B, specifically:

[0020] Lingtai District Logo Matrix Among them B i Indicates the symbol and of the ith station area, 1≤i≤n, the combined area mark matrix and the area name matrix form matrix C:

[0021]

[0022] Where N iis the name of the i-th station area. The matrix C is sorted in descending order of the station area sign and the station area name. Therefore, the station area in the first row has the largest sign and the largest sign. After sorting in descending order, if the station area in the first row is the k-th station area, the reference station area is selected as follows:

[0023] 1) If B k = m, then only one reference area is selected, and the reference area is N k ;

[0024] 2) If B k <m, then first determine the first reference area as N k , follow the steps below to determine other reference areas:

[0025] Step 1: For And i≠k, if j st COV(a i,j ,a k,j )>YZ, then go to step ②, otherwise it will prompt “Cannot complete reference area determination”;

[0026] Step 2:

[0027] Extract the flags of the zones i and k If b i,q =1 or b k,q =1, then let b i-k,q =1, otherwise let b i-k,q =0, where 1≤q≤n, b i-k,q Indicates the joint symbol of the zones i and k, COV(a i,j ,a k,j ) is the Pearson correlation coefficient of the voltage curves of the stations i and k on the jth day, YZ is the threshold of the correlation coefficient, and the calculation of the results for n days is completed to obtain the marker matrix B of the stations i and k. i-k for:

[0028]

[0029] Step 3: If |B i-k |=m, then area i is determined as the second reference area, and a prompt "Complete reference area determination" is displayed;

[0030] If | B i-k |<m, the prompt "Unable to complete reference area determination" will be displayed.

[0031] Furthermore, in step D, the voltage curve similarity of the area is calculated according to the reference area determined in step C, specifically:

[0032] ① If there is only one reference area, the correlation coefficients of the voltage curves of other areas and the reference area are calculated respectively, and the similarity of the voltage curves is represented by the size of the correlation coefficient;

[0033] ② If there are two reference areas, the first reference area is used to calculate the voltage curve correlation coefficient between other areas and the reference area. When the voltage curve of the first reference area is missing, the voltage curve correlation coefficient between other areas and the second reference area is calculated, and the similarity of the voltage curve is characterized by the size of the correlation coefficient;

[0034] ③ If the prompt "Unable to complete the reference area determination" is displayed, the area voltage curve similarity will not be calculated.

[0035] The present invention provides a voltage curve similarity calculation method considering reference substations. When there is no 10kV line voltage curve, the 10kV bus voltage curve is represented by the reference substation, and the substation voltage curve similarity can also be calculated, which can provide a data basis for the substation line-transformer relationship verification. The reference substation determination method proposed by the present invention can ensure that when there is no 10kV bus point voltage curve, especially when there is an error in the substation line-transformer relationship itself, the correct calculation of the substation similarity can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of one embodiment of a method for calculating voltage curve similarity considering a reference station area according to the present invention. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0038] See also Figure 1 , is a flow chart of one embodiment of a method for calculating voltage curve similarity considering a reference area of ​​the present invention, the method comprising the following steps:

[0039] A. Obtaining the relevant data of the substation, which includes: the correspondence between the 10kV line and the substation, the substation name, the substation address code, and the voltage data of 96 points at the substation outlet;

[0040] B. Preprocess the obtained distribution transformer outlet voltage data, specifically:

[0041] Assuming that a 10kV line has n substations and m days of data are collected, the substation set can be recorded as:

[0042]

[0043] where a i,j represents the calculated voltage curve of the ith substation on the jth day, 1≤i≤n, 1≤j≤m, a i,j Contains 96 points of voltage data for one day, which can be recorded as If for any All meet ≠ null value, then let area a i,j Logo of b i,j =1, otherwise let area a i,j Logo of b i,j =0.

[0044] All stations are preprocessed according to the above method to form the station mark matrix B:

[0045]

[0046] C. Determine the reference area according to the area marker matrix preprocessed in step B, specifically:

[0047] Lingtai District Logo Matrix Among them B i Indicates the symbol and of the ith station area, 1≤i≤n, the combined area mark matrix and the area name matrix form a matrix C

[0048]

[0049] Where N i is the name of the i-th station area. Sort the matrix C in descending order of station area sign and station area name, so the station area in the first row has the largest sign and the largest sign. After descending sorting, if the station area in the first row is the k-th station area. The reference station area is selected as follows:

[0050] 1) If B k = m, then only one reference area is selected, and the reference area is N k ;

[0051] 2) If B k <m, then first determine the first reference area as N k , follow the steps below to determine other reference areas.

[0052] Step 1: For And i≠k, if j st COV(a i,j ,a k,j )>YZ, then go to step ②, otherwise it will prompt “Cannot complete reference area determination”;

[0053] Step 2:

[0054] Extract the flags of the zones i and k If b i,q =1 or b k,q =1, then let b i-k,q =1, otherwise let b i-k,q = 0. Where 1≤q≤n, b i-k,qIndicates the joint symbol of the zones i and k, COV(a i,j ,a k,j ) is the Pearson correlation coefficient of the voltage curves of the stations i and k on the jth day, and YZ is the threshold of the correlation coefficient. After the calculation of the results for n days, the marker matrix B of the stations i and k can be obtained. i-k for:

[0055]

[0056] Step 3: If |B i-k |=m, then the station area i can be determined as the second reference station area, and a prompt "Complete reference station area determination" is displayed.

[0057] If | B i-k |<m, the prompt "Unable to complete reference area determination" will be displayed.

[0058] D. Calculate the similarity of the voltage curves of the reference area determined in step C, specifically:

[0059] ① If there is only one reference area, the correlation coefficients of the voltage curves of other areas and the reference area are calculated respectively, and the similarity of the voltage curves is represented by the size of the correlation coefficient;

[0060] ② If there are two reference areas, the first reference area is used to calculate the voltage curve correlation coefficient between other areas and the reference area. When the voltage curve of the first reference area is missing, the voltage curve correlation coefficient between other areas and the second reference area is calculated, and the similarity of the voltage curve is characterized by the size of the correlation coefficient.

[0061] ③ If the prompt "Unable to complete the reference area determination" is displayed, the area voltage curve similarity will not be calculated

[0062] The technical solution and effects of the present invention are described in detail below with a specific embodiment:

[0063] Implementation Case 1: A Reference Area

[0064] In step A, the distribution transformer outlet voltage data of 13 substations on a 10 kV line for 10 days is obtained from the relevant system. Table 1 shows sample data for one day.

[0065] Table 1

[0066]

[0067] In step B, the acquired voltage data is preprocessed to obtain a sign matrix as shown in Table 2:

[0068] Table 2

[0069]

[0070]

[0071] In step C, according to the calculation results in step B, a matrix C is formed, as shown in Table 3:

[0072] Table 3

[0073] District Name Logo NP4 10 NP2 10 NP13 10 NP1 10 NP9 9 NP8 9 NP7 9 NP6 9 NP5 9 NP3 9 NP12 9 NP11 9 NP10 9

[0074] According to matrix C, since B NP4 = 10. Therefore, NP4 can be determined as the reference stage.

[0075] In step D, the voltage curve similarity of the area is calculated according to the reference area determined in step C, as shown in Table 4:

[0076] Table 4

[0077] District Name Similarity with reference area Data date NP4 (reference area) 1 4-1 NP2 0.95 4-1 NP13 0.96 4-1 NP1 0.95 4-1 NP9 0.97 4-1 NP8 0.91 4-1 NP7 0.94 4-1 NP6 0.95 4-1 NP5 0.96 4-1 NP3 0.98 4-1 NP12 0.97 4-1 NP11 0.95 4-1 NP10 0.93 4-1

[0078] Implementation Case 2: Two Reference Areas

[0079] Step A: The distribution transformer outlet voltage data of 8 substations on a 10kV line for 5 days is obtained from the relevant system. Table 5 is a sample data of 1 day.

[0080] Table 5

[0081]

[0082] In step B, the acquired voltage data is preprocessed to obtain a sign matrix as shown in Table 6:

[0083] Table 6

[0084]

[0085]

[0086] In step C, according to the calculation results in step B, a matrix C is formed, as shown in Table 7:

[0087] Table 7

[0088] District Name Logo TQ1 4 TQ2 4 TQ3 4 TQ4 4 TQ5 4 TQ6 4 TQ7 4 TQ8 4

[0089] Because B TQ1 =4, which is less than the number of data days 5, so the station area TQ1 is first determined as the first reference station area, and then the second reference station area is determined.

[0090] Calculate the correlation coefficient of the voltage curve of other substations and substation TQ1. The calculation results are shown in Table 8:

[0091] Table 8

[0092]

[0093] The threshold value YZ of the correlation coefficient is set to 0.99. According to the calculation results, it can be seen that the station TQ3 meets the judgment condition of the second reference station, so TQ3 is set as the second reference station.

[0094] In step D, the voltage curve similarity of the area is calculated according to the reference area determined in step C. The calculation results are shown in Table 9:

[0095] Table 9

[0096]

[0097] From the above calculation results, it can be seen that the correlation coefficients of the voltage curves of the substations TQ1, TQ3, TQ4, and TQ5 are very close to 1, which are the first type of substations, while the correlation coefficients of the voltage curves of the substations TQ2, TQ6, TQ7, and TQ8 are very close to 1, which are the second type of substations. The on-site verification is consistent with the actual results.

[0098] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by technicians in this technical field within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for calculating the similarity of voltage curves considering a reference area, characterized in that The following steps are involved: A. Obtaining the relevant data of the substation, which includes: the correspondence between the 10kV line and the substation, the substation name, the substation address code, and the voltage data of 96 points at the substation outlet; B. Based on the 96-point voltage data of the distribution transformer outlet obtained in step A, pre-process the data to form a substation marking matrix; C. Determine the reference area according to the area marker matrix preprocessed in step B; D. Calculate the similarity of the voltage curves of the reference area determined in step C; In step B, the data is preprocessed, specifically: Assuming that a 10kV line has n substations and m days of data are collected, the substation set is recorded as: where a i,j represents the calculated voltage curve of the ith substation on the jth day, 1≤i≤n, 1≤j≤m, a i,j Contains 96 points of voltage data for one day, recorded as If for any All meet Then let area a i,j Logo of b i,j =1, otherwise let area a i,j Logo of b i,j =0; All stations are preprocessed according to the above method to form the station mark matrix B: In step C, the reference area is determined according to the area marker matrix preprocessed in step B, specifically: Lingtai District Logo Matrix Among them B i Indicates the symbol and of the ith station area, Combine the area sign matrix and the area name to form matrix C: Where N i is the name of the i-th station area. The matrix C is sorted in descending order of the station area sign and the station area name. Therefore, the station area in the first row has the largest sign and the largest sign. After sorting in descending order, if the station area in the first row is the k-th station area, the reference station area is selected as follows: 1) If B k = m, then only one reference area is selected, and the reference area is N k ; 2) If B k <m, then first determine the first reference area as N k , follow the steps below to determine other reference areas: Step 1: For And i≠k, if Then go to step ②, otherwise it will prompt "Unable to complete reference area determination"; Step 2: Extract the flags of the zones i and k If b i,q =1 or b k,q =1, then let b i-k,q =1, otherwise let b i-k,q =0, where 1≤q≤n, b i-k,q Indicates the joint symbol of the zones i and k, COV(a i,j ,a k,j ) is the Pearson correlation coefficient of the voltage curves of the stations i and k on the jth day, YZ is the threshold of the correlation coefficient, and the calculation of the results for n days is completed to obtain the marker matrix B of the stations i and k. i-k for: Step 3: If |B i-k | = m, then the area i is determined as the second reference area, and a prompt "Complete reference area determination" is displayed; If | B i-k |<m, then the prompt "Cannot complete reference area determination"; In step D, the voltage curve similarity of the area is calculated according to the reference area determined in step C, specifically: ① If there is only one reference area, the correlation coefficients of the voltage curves of other areas and the reference area are calculated respectively, and the similarity of the voltage curves is represented by the size of the correlation coefficient; ② If there are two reference areas, the first reference area is used to calculate the voltage curve correlation coefficient between other areas and the reference area. When the voltage curve of the first reference area is missing, the voltage curve correlation coefficient between other areas and the second reference area is calculated, and the similarity of the voltage curve is characterized by the size of the correlation coefficient; ③ If the prompt "Unable to complete the reference area determination" is displayed, the area voltage curve similarity will not be calculated.

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