Calculation Method and System for Low-Voltage Distribution Area Topology Identification Based on Voltage Differential Linearity Determination

Abstract

This invention discloses a calculation method and system for low-voltage transformer area topology identification based on voltage differential linearity determination. The method includes: phase sequence identification based on voltage correlation to restore and correct data from out-of-order A-phase, B-phase, and C-phase wiring of field metering devices; calculation of the correlation coefficient between sub-meters and assessment meters to identify the relationship between households and transformers; calculation of upstream and downstream subordination relationships by combining voltage distribution patterns and branch voltage-power linear differential determination to achieve online low-voltage topology identification. This achieves low-voltage topology identification without adding field equipment, relying on collected voltage and power data. It only requires determining whether the voltage differential and sub-user power satisfy linearity to determine branch affiliation, with a clear mechanism. The topology splicing of the entire transformer area is achieved through iterative calculation of branch affiliation. This method can identify out-of-order phase sequence of electricity meter wiring, household-transformer relationships, and the affiliation of branch relationships.

Description

Technical Field

[0001] This invention relates to the field of power grid technology - power marketing - low-voltage distribution area topology identification technology, specifically to a calculation method and system for low-voltage distribution area topology identification based on voltage differential linearity determination. Background Technology

[0002] For key business areas of power grid enterprises, such as synchronous line loss, distribution network dispatching, and precise outage repair, accurate low-voltage topology is the core foundation supporting related applications, and its correctness directly determines the calculation model for these businesses. However, due to frequent load switching and daily maintenance work in distribution substations, the actual connection topology of the physical power grid often changes dynamically. Meanwhile, existing monitoring devices identify the topology based on the neutral line of the distribution transformer, which cannot identify substations sharing a neutral line, and the monitoring coverage is still limited, failing to achieve full-area online monitoring and real-time topology verification. This results in the topology information in the power grid system's backend database not being completely consistent with the actual physical electrical topology, leading to errors in topology connections. This topology inconsistency directly causes problems such as deviations in the calculation of power supply and sales within the same substation area and difficulty in accurately locating the outage range of distribution network dispatching to individual households, seriously impacting the operational decisions and production management of power grid enterprises. Therefore, research on low-voltage topology online identification technology based on limited measurement data has significant theoretical value and practical application significance. In this invention, the power curves of 96 user electricity meters and the power curves of 96 transformer area assessment electricity meters are derived from the electricity consumption information collection system. The electricity meters in the power grid collect data to HPLC or 485 line and transmit it to the main station via 4G network through the concentrator. The main station is the electricity consumption information collection system. Summary of the Invention

[0003] The purpose of this invention is to address the problem in existing technologies where frequent load switching and routine maintenance in distribution substations cause dynamic changes in the actual connection topology of the physical power grid. Furthermore, existing monitoring devices identify the topology based on the neutral line of the distribution transformer, which is insufficient for areas sharing a neutral line, and the monitoring coverage remains limited, failing to achieve full-area online monitoring and real-time topology verification. This results in the topology information in the power grid system's backend database not being completely consistent with the actual physical electrical topology, leading to errors in topology connections.

[0004] To address the aforementioned issues, this invention provides a calculation method for low-voltage distribution area topology identification based on voltage differential linearity determination, comprising: calculating the strength of the linear correlation between the 96-point power curves of the user voltmeter and the 96-point power curve of the distribution area assessment voltmeter based on the 96-point power curve of the user voltmeter and the distribution area assessment voltmeter.

[0005] Based on the strength of the linear correlation, the weighting coefficients of the voltage curves of phase A, phase B, and phase C of the user's voltmeter and the voltage curves of phase A, phase B, and phase C of the transformer area's assessment voltmeter are calculated respectively to determine the disordered wiring sequence of the metering device.

[0006] Calculate the weighting coefficient between the user's voltmeter and the transformer area assessment voltmeter. If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area assessment voltmeter is less than 0.5 and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area.

[0007] Once it is determined that a user does not belong to this area, their data will be removed.

[0008] The difference between the voltages of User 1, User 2, and User 3 is multiplied by the user's voltage using the following formula:

[0009]

[0010] In the formula, U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance.

[0011] It can be seen that only when User 1 and User 2 are in the same branch and have a membership relationship, the differential voltage has a linear relationship with the user power and is not related to the voltage of the transformer area assessment voltmeter. Other differential voltages have a complex nonlinear relationship with the user power and are related to the voltage of the transformer area assessment voltmeter.

[0012] Therefore, the rule for determining the upstream and downstream relationship of a branch is derived, and the formula is:

[0013]

[0014] In the formula, β is the power factor angle of the low-voltage user. This represents the voltage difference between user i and user j. and Let represent the voltages of user j and user i, respectively, and f represent the branch determination coefficient, where user j is a downstream user on the same branch as user i. For the active power of user j, the strength of the linear correlation is calculated using the cosine angle, and the formula is:

[0015]

[0016] in, This represents the voltage value collected by user i at time t. This represents the voltage difference between user i and user j collected at time t.

[0017] This represents the active power value collected by user j at time t. Both power and voltage are represented by 96-point curves as column vectors.

[0018] When user j is a downstream user on the same branch as user i, the angle α approaches 0; if α≈0, then user j is downstream of user i on the same branch.

[0019] This leads to the determination of whether a user belongs to the same branch road and its upstream and downstream.

[0020] In the preferred embodiment, it includes:

[0021] The relationship between the voltage of the user meter and the voltage of the voltage meter in the transformer area assessment is as follows:

[0022]

[0023] Where U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance;

[0024] As can be seen from the formula, the user voltage at any level in the low-voltage distribution network topology and the voltage of the distribution network assessment voltmeter can be written in general form as follows:

[0025]

[0026] Where ΔU represents the voltage difference, it can be seen that the voltage of the user's voltmeter and the voltage of the transformer area assessment voltmeter are linearly related;

[0027] The strength of the linear correlation between the power curves of 96 points on the user voltmeter and the transformer area assessment voltmeter is calculated using the following formula:

[0028]

[0029] in, As weight, The weighted average voltage value. The average active power. Indicates the weighting coefficients of the voltage curve;

[0030] Calculate the weighting factors for the voltage curves of phases A, B, and C of the user's voltmeter and the voltage curves of phases A, B, and C of the transformer area's assessment voltmeter, respectively. If the value exists, the wiring sequence of the metering device is determined to be disordered based on the relationship. The formula is:

[0031]

[0032] In the formula, The phase sequence for the user's voltmeter. To determine the phase sequence of the voltmeter in the transformer substation area. This represents the weighting factor of the user's voltmeter. This represents the weighting coefficient of the user voltmeter and the voltage meter for the area assessment; the set represents the set where, under the user voltmeter selection of phase sequence A, B, and C, there exists a phase sequence for the voltage meter for the area assessment, and the weighted correlation coefficient between the user voltmeter and the corresponding phase of the voltage meter for the area assessment is less than 0.5, but the maximum weighted correlation coefficient with the other two non-corresponding phases is greater than 0.95; |•| represents the number of elements in the set, i.e., when the number of elements in the set that meet the requirements is greater than 2, i.e., at least 2 phases meet the constraints within the set, it is judged that the voltage sequence of the metering device is disordered; after the metering device is judged to be disordered, the disordered data is restored and corrected according to the phase sequence corresponding to the maximum weighting coefficient; the weighting coefficient between the user voltmeter and the voltage meter for the area assessment is calculated, satisfying the formula:

[0033]

[0034] If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area; once it is determined that the user does not belong to this transformer area, the user's data is removed.

[0035] In the preferred embodiment, the metering device includes: a current transformer, a junction box, and an energy meter.

[0036] In the preferred mode, the power curves of the user voltmeter at 96 points and the power curves of the transformer area assessment voltmeter at 96 points are plotted based on the ratio of the electrical energy consumed by the user's electricity meter and the transformer area assessment electricity meter in 96 hours to the time.

[0037] A calculation system for low-voltage distribution area topology identification based on voltage differential linearity determination includes: a module for determining wiring disorder and a user affiliation module;

[0038] The module for determining disordered wiring is based on the 96-point power curves of the user voltmeter and the 96-point power curves of the transformer area assessment voltmeter. It calculates the strength of the linear correlation between the power curves of the user voltmeter and the transformer area assessment voltmeter. Based on the strength of the linear correlation, it calculates the weighting coefficients between the voltage curves of phase A, phase B, and phase C of the user voltmeter and the voltage curves of phase A, phase B, and phase C of the transformer area assessment voltmeter, and determines the disordered wiring sequence of the metering device.

[0039] The user affiliation module is based on the weighted coefficients of the user's voltmeter and the transformer area assessment voltmeter. If the maximum value of the weighted coefficient of any non-corresponding phase of the user's voltmeter and the transformer area assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area. When it is determined that the user does not belong to this transformer area, the user's data is removed. The difference between the voltages of user 1, user 2, and user 3 is calculated and multiplied by the user's voltage to derive the rules for determining the upstream and downstream relationships of the branch. The strength of the linear correlation is calculated using the cosine angle to determine whether the user belongs to the same branch and its upstream and downstream.

[0040] In the preferred approach, the module for determining out-of-order wiring is implemented as follows:

[0041] The relationship between the voltage of the user meter and the voltage of the voltage meter in the transformer area assessment is as follows:

[0042]

[0043] Where U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance;

[0044] As can be seen from the formula, the voltage of the user voltmeter at any level in the low-voltage distribution area topology and the voltage of the distribution area assessment voltmeter can be written in general form as follows:

[0045]

[0046] Where ΔU represents the voltage difference, it can be seen that the voltage of the user's voltmeter and the voltage of the transformer area assessment voltmeter are linearly related;

[0047] The strength of the linear correlation between the power curves of 96 points on the user voltmeter and the transformer area assessment voltmeter is calculated using the following formula:

[0048]

[0049] in, As weight, The weighted average voltage value. The average active power. Indicates the weighting coefficients of the voltage curve;

[0050] Calculate the weighting factors for the voltage curves of phases A, B, and C of the user's voltmeter and the voltage curves of phases A, B, and C of the transformer area's assessment voltmeter, respectively. If the value exists, the wiring sequence of the metering device is determined to be disordered based on the relationship. The formula is:

[0051]

[0052] In the formula, The phase sequence for the user's voltmeter. To determine the phase sequence of the voltmeter in the transformer substation area. This represents the weighting factor of the user's voltmeter. This indicates the weighting coefficient of the user's voltmeter area assessment voltmeter;

[0053] The set is represented as follows: when the user voltmeter selects phase sequence A, B, C, there is a phase sequence of the transformer area assessment voltmeter. The weighted correlation coefficient between the user voltmeter and the corresponding phase of the transformer area assessment voltmeter is less than 0.5, but the maximum weighted correlation coefficient with the other two non-corresponding phases is greater than 0.95.

[0054] |•| indicates the number of elements in the set. If the number of elements in the set that meet the requirements is greater than 2, that is, if at least 2 elements meet the constraints in the set, then it is judged that the voltage of the metering device is out of order.

[0055] After determining that the metering device is out of sequence, the out-of-sequence data is restored and corrected according to the phase sequence corresponding to the maximum weighting coefficient.

[0056] In the preferred approach, the user's assigned module is implemented as follows:

[0057] Calculate the weighting factor for the user voltmeter and the transformer area assessment voltmeter, satisfying the formula:

[0058]

[0059] If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area's assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area.

[0060] Once it is determined that a user does not belong to this area, their data will be removed.

[0061] The difference between the voltages of User 1, User 2, and User 3 is multiplied by the user's voltage using the following formula:

[0062]

[0063] It can be seen that only when User 1 and User 2 are in the same branch and have a membership relationship, the differential voltage has a linear relationship with the user power and is not related to the voltage of the transformer area assessment voltmeter. Other differential voltages have a complex nonlinear relationship with the user power and are related to the voltage of the transformer area assessment voltmeter.

[0064]

[0065] In the formula, β is the power factor angle of the low-voltage user. This represents the voltage difference between user i and user j. and Let represent the voltages of user j and user i, respectively, and f represent the branch determination coefficient, where user j is a downstream user on the same branch as user i. For the active power of user j, the strength of the linear correlation is calculated using the cosine angle, and the formula is:

[0066]

[0067] in, This represents the voltage value collected by user i at time t. This represents the voltage difference between user i and user j collected at time t. Let α represent the active power value collected by user j at time t. Both power and voltage are represented by a 96-point curve as a column vector. When user j is a downstream user of user i on the same branch, the angle α approaches 0. If α≈0, then user j is downstream of user i on the same branch. This leads to the determination of whether a user belongs to the same branch and its upstream and downstream.

[0068] The beneficial effects of this invention are: It can identify low-voltage topology relationships without adding on-site equipment, relying on collected voltage and power data. Branch affiliation can be determined simply by judging whether the voltage difference and sub-user power satisfy linearity; the mechanism is clear, and the topology splicing of the entire distribution area is achieved through iterative calculation of branch affiliation. It can identify disordered phase sequence of electricity meter wiring voltage, household-transformer relationships, and branch affiliation relationships. Attached Figure Description

[0069] Figure 1 This is a schematic diagram of the calculation process of the present invention;

[0070] Figure 2 This is the intended result of the system query in this invention;

[0071] Figure 3 This is a schematic diagram illustrating the correlation calculation between phase A of the user voltmeter and the voltage of the two distribution transformer areas according to the present invention.

[0072] Figure 4 This is a schematic diagram illustrating the correlation calculation between phase B of the user voltmeter and the voltage of the two distribution transformer areas in this invention.

[0073] Figure 5 This is a schematic diagram illustrating the correlation calculation between the C phase of the user voltmeter and the voltage of the two distribution transformer areas according to the present invention.

[0074] Figure 6 This is a schematic representation of the phase sequence adjustment calculation for user voltmeter A in this invention;

[0075] Figure 7 This is a schematic representation of the phase sequence adjustment calculation for user voltmeter B in this invention;

[0076] Figure 8 This is a schematic representation of the phase sequence adjustment calculation for the user voltmeter C in this invention;

[0077] Figure 9 This is a schematic diagram of the C-phase voltage curve of the Xiangyang Branch 14 Left 5th Unit Area of ​​the present invention;

[0078] Figure 10 This is a schematic diagram illustrating the determination of the linear membership relationship between the product of voltage difference and the assessment table and power in this invention.

[0079] Figure 11 This is a schematic diagram of the transformer area topology of the present invention;

[0080] Figure 12This is a schematic diagram of the overall topology of the transformer area in this invention. Detailed Implementation

[0081] Example 1: A calculation method for low-voltage distribution area topology identification based on voltage differential linearity determination, comprising:

[0082] Based on the 96-point power curves of the user voltmeter and the 96-point power curves of the transformer area assessment voltmeter, calculate the strength of the linear correlation between the 96-point power curves of the user voltmeter and the transformer area assessment voltmeter.

[0083] Based on the strength of the linear correlation, the weighting coefficients of the voltage curves of phase A, phase B, and phase C of the user's voltmeter and the voltage curves of phase A, phase B, and phase C of the transformer area's assessment voltmeter are calculated respectively to determine the disordered wiring sequence of the metering device.

[0084] Calculate the weighting coefficient between the user's voltmeter and the transformer area assessment voltmeter. If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area assessment voltmeter is less than 0.5 and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area.

[0085] Once it is determined that a user does not belong to this area, their data will be removed.

[0086] The difference between the voltages of User 1, User 2, and User 3 is multiplied by the user's voltage using the following formula:

[0087]

[0088] In the formula, U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance.

[0089] It can be seen that only when User 1 and User 2 are in the same branch and have a membership relationship, the differential voltage has a linear relationship with the user power and is not related to the voltage of the transformer area assessment voltmeter. Other differential voltages have a complex nonlinear relationship with the user power and are related to the voltage of the transformer area assessment voltmeter.

[0090] Therefore, the rule for determining the upstream and downstream relationship of a branch is derived, and the formula is:

[0091]

[0092] In the formula, β is the power factor angle of the low-voltage user. This represents the voltage difference between user i and user j. and Let f represent the voltages of user j and user i, respectively. User j is a downstream user of user i on the same branch. f represents the branch determination coefficient. For the active power of user j, the strength of the linear correlation is calculated using the cosine angle, and the formula is:

[0093]

[0094] in, This represents the voltage value collected by user i at time t. This represents the voltage difference between user i and user j collected at time t.

[0095] This represents the active power value collected by user j at time t. Both power and voltage are represented by 96-point curves as column vectors.

[0096] When user j is a downstream user on the same branch as user i, the angle α approaches 0; if α≈0, then user j is downstream of user i on the same branch.

[0097] This leads to the determination of whether a user belongs to the same branch road and its upstream and downstream.

[0098] The relationship between the voltage of the user meter and the voltage of the voltage meter in the transformer area assessment is as follows:

[0099]

[0100] Where U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance;

[0101] As can be seen from the formula, the user voltage at any level in the low-voltage distribution network topology and the voltage of the distribution network assessment voltmeter can be written in general form as follows:

[0102]

[0103] Where ΔU represents the voltage difference, it can be seen that the voltage of the user's voltmeter and the voltage of the transformer area assessment voltmeter are linearly related;

[0104] The strength of the linear correlation between the power curves of 96 points on the user voltmeter and the transformer area assessment voltmeter is calculated using the following formula:

[0105]

[0106] in, As weight, The weighted average voltage value. The average active power. Indicates the weighting coefficients of the voltage curve;

[0107] Calculate the weighting factors for the voltage curves of phases A, B, and C of the user's voltmeter and the voltage curves of phases A, B, and C of the transformer area's assessment voltmeter, respectively. If the value exists, the wiring sequence of the metering device is determined to be disordered based on the relationship. The formula is:

[0108]

[0109] In the formula, The phase sequence for the user's voltmeter. To determine the phase sequence of the voltmeter in the transformer substation area. This represents the weighting factor of the user's voltmeter. This represents the weighting coefficient of the user voltmeter and the voltage meter for the area assessment; the set represents the set where, under the user voltmeter selection of phase sequence A, B, and C, there exists a phase sequence for the voltage meter for the area assessment, and the weighted correlation coefficient between the user voltmeter and the corresponding phase of the voltage meter for the area assessment is less than 0.5, but the maximum weighted correlation coefficient with the other two non-corresponding phases is greater than 0.95; |•| represents the number of elements in the set, i.e., when the number of elements in the set that meet the requirements is greater than 2, i.e., at least 2 phases meet the constraints within the set, it is judged that the voltage sequence of the metering device is disordered; after the metering device is judged to be disordered, the disordered data is restored and corrected according to the phase sequence corresponding to the maximum weighting coefficient; the weighting coefficient between the user voltmeter and the voltage meter for the area assessment is calculated, satisfying the formula:

[0110]

[0111] If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area; once it is determined that the user does not belong to this transformer area, the user's data is removed.

[0112] Metering devices include: current transformers, junction boxes, and electricity meters.

[0113] The power curves of the user voltmeter at 96 points and the power curves of the transformer area assessment voltmeter at 96 points are plotted based on the ratio of the electrical energy consumed by the user's electricity meter and the transformer area assessment electricity meter over 96 hours to the time.

[0114] A calculation system for low-voltage distribution area topology identification based on voltage differential linearity determination includes: a module for determining wiring disorder and a user affiliation module;

[0115] The module for determining disordered wiring is based on the 96-point power curves of the user voltmeter and the 96-point power curves of the transformer area assessment voltmeter. It calculates the strength of the linear correlation between the power curves of the user voltmeter and the transformer area assessment voltmeter. Based on the strength of the linear correlation, it calculates the weighting coefficients between the voltage curves of phase A, phase B, and phase C of the user voltmeter and the voltage curves of phase A, phase B, and phase C of the transformer area assessment voltmeter, and determines the disordered wiring sequence of the metering device.

[0116] The user affiliation module is based on the weighted coefficients of the user's voltmeter and the transformer area's assessment voltmeter. If the maximum value of the weighted coefficient of any non-corresponding phase of the user's voltmeter and the transformer area's assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area. When it is determined that the user does not belong to this transformer area, the user's data is removed. The difference between the voltages of user 1, user 2, and user 3 is calculated and multiplied by the user's voltage to derive the rules for determining the upstream and downstream relationships of the branch. The strength of the linear correlation is calculated using the cosine angle to determine whether the user belongs to the same branch and its upstream and downstream.

[0117] The module for determining out-of-order wiring is implemented as follows:

[0118] The relationship between the voltage of the user meter and the voltage of the voltage meter in the transformer area assessment is as follows:

[0119]

[0120] Where U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance;

[0121] As can be seen from the formula, the voltage of the user voltmeter at any level in the low-voltage distribution area topology and the voltage of the distribution area assessment voltmeter can be written in general form as follows:

[0122]

[0123] Where ΔU represents the voltage difference, it can be seen that the voltage of the user's voltmeter and the voltage of the transformer area assessment voltmeter are linearly related;

[0124] The strength of the linear correlation between the power curves of 96 points on the user voltmeter and the transformer area assessment voltmeter is calculated using the following formula:

[0125]

[0126] in, As weight, The weighted average voltage value. The average active power. Indicates the weighting coefficients of the voltage curve;

[0127] Calculate the weighting factors for the voltage curves of phases A, B, and C of the user's voltmeter and the voltage curves of phases A, B, and C of the transformer area's assessment voltmeter, respectively. If the value exists, the wiring sequence of the metering device is determined to be disordered based on the relationship. The formula is:

[0128]

[0129] In the formula, The phase sequence for the user's voltmeter. To determine the phase sequence of the voltmeter in the transformer substation area. This represents the weighting factor of the user's voltmeter. This indicates the weighting coefficient of the user's voltmeter area assessment voltmeter;

[0130] The set is represented as follows: when the user voltmeter selects phase sequence A, B, C, there is a phase sequence of the transformer area assessment voltmeter. The weighted correlation coefficient between the user voltmeter and the corresponding phase of the transformer area assessment voltmeter is less than 0.5, but the maximum weighted correlation coefficient with the other two non-corresponding phases is greater than 0.95.

[0131] |•| indicates the number of elements in the set. If the number of elements in the set that meet the requirements is greater than 2, that is, if at least 2 elements meet the constraints in the set, then it is judged that the voltage of the metering device is out of order.

[0132] After determining that the metering device is out of sequence, the out-of-sequence data is restored and corrected according to the phase sequence corresponding to the maximum weighting coefficient.

[0133] The user's membership module is implemented as follows:

[0134] Calculate the weighting factor for the user voltmeter and the transformer area assessment voltmeter, satisfying the formula:

[0135]

[0136] If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area's assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area.

[0137] Once it is determined that a user does not belong to this area, their data will be removed.

[0138] The difference between the voltages of User 1, User 2, and User 3 is multiplied by the user's voltage using the following formula:

[0139]

[0140] It can be seen that only when User 1 and User 2 are in the same branch and have a membership relationship, the differential voltage has a linear relationship with the user power and is not related to the voltage of the transformer area assessment voltmeter. Other differential voltages have a complex nonlinear relationship with the user power and are related to the voltage of the transformer area assessment voltmeter.

[0141]

[0142] In the formula, β is the power factor angle of the low-voltage user. This represents the voltage difference between user i and user j. and Let f represent the voltages of user j and user i, respectively. User j is a downstream user of user i on the same branch. f represents the branch determination coefficient. For the active power of user j, the strength of the linear correlation is calculated using the cosine angle, and the formula is:

[0143]

[0144] in, This represents the voltage value collected by user i at time t. This represents the voltage difference between user i and user j collected at time t. Let α represent the active power value collected by user j at time t. Both power and voltage are represented by a 96-point curve as a column vector. When user j is a downstream user of user i on the same branch, the angle α approaches 0. If α≈0, then user j is downstream of user i on the same branch. This leads to the determination of whether a user belongs to the same branch and its upstream and downstream.

[0145] Example 2: Identification of relationship between user and transformer: On January 2, the voltage of the transformer area assessment voltmeter and the user meter were obtained, and the correlation was calculated, as shown in Table 1;

[0146] Table 1

[0147]

[0148] As shown in Table 1, users 210***0576 and 210***0773 have low maximum correlation coefficients (less than 0.8) with the voltage phase sequences of the voltmeters in the transformer substation area, suggesting they may not be users within this area. Furthermore, the ABC voltage phase sequence of user 210***3345 is not the same as the maximum value, raising suspicion of a misconnection between voltage phases A and B on the field meter. A system work order query revealed that both users 210***0576 and 210***0773 have undergone adjustments to their user-transformer relationships. Figure 2 As shown.

[0149] Depend on Figure 2 It can be seen that on November 9, 2024, this user was moved from Weimeipinge 1-2 transformer substation to Xiangyangfen 14-5 transformer substation. The voltage similarity between this user and the two transformer substations was calculated as follows: Figure 3 , 4 As shown in Figure 5, the red curve represents the user voltage, and the blue curve represents the voltage of the distribution transformer test meter. Therefore, from... Figure 3 , 4 As can be seen from point 5, this user should belong to the Weimeipinge platform area, but the user's profile data in the Xiangyang sub-platform area is incorrect (at the same time). Figure 2 Both the household address and the address can serve as proof.

[0150] Voltage Phase Sequence Identification: In actual operation, there are instances of disordered voltage meter wiring, as seen in user 210***3345 in Table 1. From left to right, terminals are numbered 1-11. Terminals 2 and 5 are the A and B phase terminals, respectively. Terminal 2 should be connected to the yellow A phase voltage, and terminal 5 should be connected to the green B phase voltage. The meter also displays yellow, green, and red dots above the terminals to indicate the wiring sequence. Connecting the yellow A phase voltage to terminal 5 and the green B phase voltage to terminal 2 causes the system to monitor the A and B phase voltages in reverse, resulting in the discrepancy between the maximum voltage correlation coefficient and the phase sequence for user 210***3345 in Table 1. A comparison of this user's voltage phase sequence before and after the reversal is provided. Figure 6 , Figure 7 , Figure 8 As shown.

[0151] Branch topology identification: For the Xiangyang branch 14# left 5 transformer, after removing two users who do not belong to this distribution area and adjusting the AB voltage phase sequence of one user, the topology calculation begins. First, the lowest voltage point is determined. Taking phase C as an example, the assessment table and the voltage curves of the three users are as follows: Figure 9 As shown. By Figure 9 The relationship among the four is: blue > purple > orange > yellow. Therefore, user 2100306990861 on the yellow curve is at the very end of the network, which is the farthest point. Figure 9 The horizontal axis represents the measurement point, and the vertical axis represents voltage. Then, the affiliation relationship between the two branches is identified by determining the linear affiliation between the voltage difference and the product of the assessment table and the power. Figure 10 As shown. Because user 0874 had zero power consumption on January 2nd, a linear fit was performed on the power consumption of the remaining two users. Figure 10 It can be seen that users 3345 and 0874 have a linear relationship as shown in Conclusion 4, so they belong to the same branch. However, users 0861 and 3345 have a non-linear relationship, so they do not belong to the same branch. Furthermore, after... Figure 9 The voltage difference shows that user 3345 is higher than user 0874, therefore 0874 is downstream of user 3345. Therefore, from the above analysis, we can conclude that:

[0152] 1. User 3345 and user 0874 are on the same branch;

[0153] 2. User 0874 is a downstream level of user 3345 in the same branch;

[0154] 3. User 0861 is another branch, and it is the furthest one.

[0155] To verify the above topological relationships, the topology of this transformer area is as follows: Figure 11As shown, user 0874 and user 3345 are on the same branch, while user 0861 is on another branch. According to the system search, 0861 is about 100 meters away from the transformer, while 0874 is about 50 meters away from the transformer. This is consistent with the above analysis conclusion.

[0156] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A calculation method for low-voltage distribution area topology identification based on voltage differential linearity determination, characterized in that, include: Based on the 96-point power curves of the user voltmeter and the 96-point power curves of the transformer area assessment voltmeter, calculate the strength of the linear correlation between the 96-point power curves of the user voltmeter and the transformer area assessment voltmeter. Based on the strength of the linear correlation, the weighting coefficients of the voltage curves of phase A, phase B, and phase C of the user's voltmeter and the voltage curves of phase A, phase B, and phase C of the transformer area's assessment voltmeter are calculated respectively to determine the disordered wiring sequence of the metering device. Calculate the weighting coefficient between the user's voltmeter and the transformer area assessment voltmeter. If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area assessment voltmeter is less than 0.5 and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area. Once it is determined that a user does not belong to this area, their data will be removed. The difference between the voltages of User 1, User 2, and User 3 is multiplied by the user's voltage using the following formula: In the formula, U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance. It can be seen that only when User 1 and User 2 are in the same branch and have a membership relationship, the differential voltage has a linear relationship with the user power and is not related to the voltage of the transformer area assessment voltmeter. Other differential voltages have a complex nonlinear relationship with the user power and are related to the voltage of the transformer area assessment voltmeter. Therefore, the rule for determining the upstream and downstream relationship of a branch is derived, and the formula is: In the formula, β is the power factor angle of the low-voltage user. This represents the voltage difference between user i and user j. and Let f represent the voltages of user j and user i, respectively. User j is a downstream user of user i on the same branch. f represents the branch determination coefficient. For the active power of user j, the strength of the linear correlation is calculated using the cosine angle, and the formula is: in, This represents the voltage value collected by user i at time t. This represents the voltage difference between user i and user j collected at time t. This represents the active power value collected by user j at time t. Both power and voltage are represented by 96-point curves as column vectors. When user j is a downstream user on the same branch as user i, the angle α approaches 0; if α≈0, then user j is downstream of user i on the same branch. This leads to the determination of whether a user belongs to the same branch road and its upstream and downstream.

2. The calculation method for low-voltage distribution area topology identification based on voltage differential linearity determination according to claim 1, characterized in that, include: The relationship between the voltage of the user meter and the voltage of the voltage meter in the transformer area assessment is as follows: Where U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance; As can be seen from the formula, the user voltage at any level in the low-voltage distribution network topology and the voltage of the distribution network assessment voltmeter can be written in general form as follows: Where ΔU represents the voltage difference, it can be seen that the voltage of the user's voltmeter and the voltage of the transformer area assessment voltmeter are linearly related; The strength of the linear correlation between the power curves of 96 points on the user voltmeter and the transformer area assessment voltmeter is calculated using the following formula: in, As weight, The weighted average voltage value. The average active power. Indicates the weighting coefficients of the voltage curve; Calculate the weighting factors for the voltage curves of phases A, B, and C of the user's voltmeter and the voltage curves of phases A, B, and C of the transformer area's assessment voltmeter, respectively. If the value exists, the wiring sequence of the metering device is determined to be disordered based on the relationship. The formula is: In the formula, The phase sequence for the user's voltmeter. To determine the phase sequence of the voltmeter in the transformer substation area. This represents the weighting factor of the user's voltmeter. This represents the weighting coefficient of the user voltmeter and the voltage meter for the area assessment; the set represents the set where, under the user voltmeter selection of phase sequence A, B, and C, there exists a phase sequence for the voltage meter for the area assessment, and the weighted correlation coefficient between the user voltmeter and the corresponding phase of the voltage meter for the area assessment is less than 0.5, but the maximum weighted correlation coefficient with the other two non-corresponding phases is greater than 0.95; |•| represents the number of elements in the set, i.e., when the number of elements in the set that meet the requirements is greater than 2, i.e., at least 2 phases meet the constraints within the set, it is judged that the voltage sequence of the metering device is disordered; after the metering device is judged to be disordered, the disordered data is restored and corrected according to the phase sequence corresponding to the maximum weighting coefficient; the weighting coefficient between the user voltmeter and the voltage meter for the area assessment is calculated, satisfying the formula: If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area; once it is determined that the user does not belong to this transformer area, the user's data is removed.

3. The calculation method for low-voltage distribution area topology identification based on voltage differential linearity determination according to claim 1, characterized in that, Metering devices include: current transformers, junction boxes, and electricity meters.

4. The calculation method for low-voltage distribution area topology identification based on voltage differential linearity determination according to claim 1, characterized in that, The power curves of the user voltmeter at 96 points and the power curves of the transformer area assessment voltmeter at 96 points are plotted based on the ratio of the electrical energy consumed by the user's electricity meter and the transformer area assessment electricity meter over 96 hours to the time.

5. A computational system for low-voltage distribution area topology identification based on voltage differential linearity determination, characterized in that, include: Determine the module with disordered wiring and the module to which the user belongs; The module for determining disordered wiring is based on the 96-point power curves of the user voltmeter and the 96-point power curves of the transformer area assessment voltmeter. It calculates the strength of the linear correlation between the power curves of the user voltmeter and the transformer area assessment voltmeter. Based on the strength of the linear correlation, it calculates the weighting coefficients between the voltage curves of phase A, phase B, and phase C of the user voltmeter and the voltage curves of phase A, phase B, and phase C of the transformer area assessment voltmeter, and determines the disordered wiring sequence of the metering device. The user affiliation module is based on the weighted coefficients of the user's voltmeter and the transformer area assessment voltmeter. If the maximum value of the weighted coefficient of any non-corresponding phase of the user's voltmeter and the transformer area assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area. When it is determined that the user does not belong to this transformer area, the user's data is removed. The difference between the voltages of user 1, user 2, and user 3 is calculated and multiplied by the user's voltage to derive the rules for determining the upstream and downstream relationships of the branch. The strength of the linear correlation is calculated using the cosine angle to determine whether the user belongs to the same branch and its upstream and downstream. The user's membership module is implemented as follows: Calculate the weighting factor for the user voltmeter and the transformer area assessment voltmeter, satisfying the formula: If the maximum weighting coefficient of any non-corresponding phase of the user's voltmeter and the transformer area's assessment voltmeter is less than 0.5, and there are 3 phases, then the user does not belong to this transformer area and belongs to another transformer area. Once it is determined that a user does not belong to this area, their data will be removed. The difference between the voltages of User 1, User 2, and User 3 is multiplied by the user's voltage using the following formula: It can be seen that only when User 1 and User 2 are in the same branch and have a membership relationship, the differential voltage has a linear relationship with the user power and is not related to the voltage of the transformer area assessment voltmeter. Other differential voltages have a complex nonlinear relationship with the user power and are related to the voltage of the transformer area assessment voltmeter. In the formula, β is the power factor angle of the low-voltage user. This represents the voltage difference between user i and user j. and Let f represent the voltages of user j and user i, respectively. User j is a downstream user of user i on the same branch. f represents the branch determination coefficient. For the active power of user j, the strength of the linear correlation is calculated using the cosine angle, and the formula is: in, This represents the voltage value collected by user i at time t. This represents the voltage difference between user i and user j collected at time t. This represents the active power value collected by user j at time t. Both power and voltage are represented by a 96-point curve as a column vector. When user j is a downstream user of user i on the same branch, the angle α approaches 0. If α≈0, then user j is downstream of user i on the same branch. This leads to the determination of whether a user belongs to the same branch road and its upstream and downstream.

6. The calculation system for low-voltage distribution area topology identification based on voltage differential linearity determination according to claim 5, characterized in that, The module for determining out-of-order wiring is implemented as follows: The relationship between the voltage of the user meter and the voltage of the voltage meter in the transformer area assessment is as follows: Where U is voltage, P is active power, Q is reactive power, R is resistance, and X is reactance; As can be seen from the formula, the voltage of the user voltmeter at any level in the low-voltage distribution area topology and the voltage of the distribution area assessment voltmeter can be written in general form as follows: Where ΔU represents the voltage difference, it can be seen that the voltage of the user's voltmeter and the voltage of the transformer area assessment voltmeter are linearly related; The strength of the linear correlation between the power curves of 96 points on the user voltmeter and the transformer area assessment voltmeter is calculated using the following formula: in, As weight, The weighted average voltage value. The average active power. Indicates the weighting coefficients of the voltage curve; Calculate the weighting factors for the voltage curves of phases A, B, and C of the user's voltmeter and the voltage curves of phases A, B, and C of the transformer area's assessment voltmeter, respectively. If the value exists, the wiring sequence of the metering device is determined to be disordered based on the relationship. The formula is: In the formula, The phase sequence for the user's voltmeter. To determine the phase sequence of the voltmeter in the transformer substation area. This represents the weighting factor of the user's voltmeter. This indicates the weighting coefficient of the user's voltmeter area assessment voltmeter; The set is represented as follows: when the user voltmeter selects phase sequence A, B, C, there is a phase sequence of the transformer area assessment voltmeter. The weighted correlation coefficient between the user voltmeter and the corresponding phase of the transformer area assessment voltmeter is less than 0.5, but the maximum weighted correlation coefficient with the other two non-corresponding phases is greater than 0.

95. |•| indicates the number of elements in the set. If the number of elements in the set that meet the requirements is greater than 2, that is, if at least 2 elements meet the constraints in the set, then it is judged that the voltage of the metering device is out of order. After determining that the metering device is out of sequence, the out-of-sequence data is restored and corrected according to the phase sequence corresponding to the maximum weighting coefficient.

Images