A disturbance-resistant current transformer ratio abnormality identification method and system

Abstract

The present invention relates to the technical field of online monitoring of electric energy metering equipment, and specifically to a method and system for identifying abnormal transformation ratio of a current transformer with anti-disturbance, and the steps are as follows: obtaining line loss in a target line and the electric energy increment corresponding to a power supply transformer and an energy consumption transformer; establishing an energy conservation matrix using line loss and electric energy increment, introducing anti-disturbance parameters in the energy conservation matrix to build an objective function, solving the objective function using a differentiated creative search algorithm, and obtaining the transformation ratio of the current transformer corresponding to the power supply transformer and the current transformer corresponding to the energy consumption transformer; obtaining the archive transformation ratio of the current transformer corresponding to the power supply transformer and the energy consumption transformer, respectively calculating the difference between each transformation ratio and the corresponding archive transformation ratio, and identifying abnormal transformation ratio of the current transformer based on the difference calculation result. While realizing the rapid positioning of abnormal current transformers, the present invention can effectively improve the stability of transformation ratio solution and reduce the accuracy reduction caused by noise or numerical errors.

Description

Technical Field

[0001] The present invention relates to the technical field of online monitoring of electric energy metering equipment, and in particular to an anti-disturbance current transformer ratio abnormality identification method and system. Background Art

[0002] The distribution network transformer is responsible for converting the current information to the energy meter or other electrical measuring equipment in a certain ratio. Since the primary / secondary voltage of the voltage transformer is relatively stable, and the primary current of the current transformer will fluctuate due to load changes, the transformation ratio of the current transformer is more likely to decrease in accuracy. In addition, the energy-consuming equipment at the customer end may be at risk of being modified for power theft, so the accuracy of the transformation ratio of the energy-consuming current transformer at the customer end is directly related to whether the electricity trade settlement can be carried out normally.

[0003] At present, the detection of current transformer ratio is mainly carried out offline on-site or laboratory testing based on relevant standards and regulations. Since these test methods use offline detection, they will not only cause power outage losses during the measurement process, but also increase additional manpower and material costs. In addition, the line loss in the power system accounts for a large proportion and is not constant. The fluctuating line loss will bring difficulties to the evaluation of the current transformer ratio.

[0004] The Chinese invention patent with publication number CN114609572A provides a method for evaluating the accuracy of a current transformer ratio based on fluctuating line losses, and specifically discloses that an online evaluation model for the current transformer ratio is established to reduce the impact of line loss changes on the current transformer ratio, so as to improve the accuracy of the online evaluation of the current transformer ratio. However, the prior art still has the following problems: when the equation groups established according to different acquisition cycles are close to a multiple relationship, an approximate linear correlation may occur, which will significantly affect the accuracy of the current transformer ratio solution.

[0005] Based on this, how to improve the stability of the transformation ratio solution and reduce the accuracy loss caused by noise or numerical errors is a technical problem that needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to provide an anti-disturbance current transformer ratio abnormality identification method and system, by using line loss and electric energy increment to establish an energy conservation matrix of the target line, and introducing anti-disturbance parameters into the energy conservation matrix, building an objective function based on the energy conservation matrix, and using a differentiated creative search algorithm to solve the ratio, which can effectively improve the stability of the ratio solution and reduce the accuracy loss caused by noise or numerical errors, so as to solve the problems pointed out in the background technology.

[0007] The present invention is implemented by the following technical scheme: A disturbance-resistant current transformer ratio abnormality identification method comprises the following steps:

[0008] Obtaining line loss in a target line and electric energy increments corresponding to an energy supply transformer and an energy consumption transformer in the target line;

[0009] The energy conservation matrix of the target line is established by using the line loss and the electric energy increment, and an anti-disturbance parameter is introduced into the energy conservation matrix to build an objective function, wherein the objective function is used to solve the first transformation ratio of the current transformer corresponding to the energy supply transformer and the second transformation ratio of the current transformer corresponding to the energy consumption transformer by using a differentiated creative search algorithm;

[0010] Obtain the file transformation ratios of the current transformers corresponding to the energy supply transformer and the energy consumption transformer, calculate the differences between the first transformation ratio, the second transformation ratio and the corresponding file transformation ratio respectively, and identify abnormal transformation ratios of the current transformer based on the difference calculation results.

[0011] According to a preferred embodiment, the specific process of obtaining the line loss and the electric energy increment is as follows:

[0012] Set the collection period , the acquisition cycle Determined according to the number of energy supply transformers and energy consumption transformers in the target line;

[0013] In each of the acquisition cycles The line loss in the target line and the electric energy increment corresponding to the energy supply transformer and the energy consumption transformer in the target line are collected.

[0014] According to a preferred embodiment, the electric energy increment is determined according to the electric energy meter display values ​​corresponding to the energy supply transformer and the energy consumption transformer.

[0015] According to a preferred embodiment, the expression of the energy conservation matrix is ​​as follows:

[0016]

[0017]

[0018]

[0019]

[0020] In the above formula, The system matrix representing the energy supply transformer and the energy consumption transformer, Represents the transformation ratio matrix of the energy supply transformer and the energy consumption transformer, represents the line loss matrix, Indicates In the collection cycle The energy increment displayed by the energy meter corresponds to the energy transformer. , ,in Indicates In the collection cycle The energy increment displayed by the energy meter corresponds to the energy transformer. Indicates the number of energy supply transformers in the target line, Indicates The file ratio of the power transformer corresponding to the voltage transformer is: Indicates The file ratio of the voltage transformer corresponding to the energy supply transformer is Indicates In the collection cycle The energy consumption transformer corresponds to the energy increment displayed by the energy meter. ,in Indicates In the collection cycle The energy consumption transformer corresponds to the energy increment displayed by the energy meter. Indicates the number of energy-consuming transformers in the target line, Indicates The energy-consuming transformer corresponds to the file ratio of the voltage transformer, where Indicates The file ratio of the voltage transformer corresponding to the energy-consuming transformer is: Indicates The first transformation ratio, wherein Indicates The first transformation ratio, Indicates The second transformation ratio is Indicates The second transformation ratio, Indicates The line loss in the target line during the acquisition cycle is Indicates The line loss in the target line during a collection period.

[0021] According to a preferred embodiment, the specific process of building the objective function is as follows:

[0022] An anti-disturbance parameter is introduced into the energy conservation matrix to establish a regularization matrix. The expression of the regularization matrix is ​​as follows:

[0023]

[0024] In the above formula, Representation Matrix The transposed matrix of is the anti-disturbance parameter, the value is arrive between, For the order The identity matrix of

[0025] Build the objective function, the expression of the objective function is as follows:

[0026]

[0027] In the above formula, represents the second norm of the regularization matrix.

[0028] According to a preferred implementation, the specific process of the difference calculation is as follows:

[0029] Calculate the difference between the first ratio and the corresponding file ratio. The expression is as follows:

[0030]

[0031] In the above formula, No. The file ratio of the current transformer corresponding to the energy supply transformer is Indicates The error limit of the current transformer corresponding to each power supply transformer;

[0032] Calculate the difference between the second ratio and the corresponding file ratio. The expression is as follows:

[0033]

[0034] In the above formula, No. The file ratio of the energy-consuming transformer to the current transformer is: Indicates The error limit of the current transformer corresponding to each energy-consuming transformer.

[0035] According to a preferred embodiment, the specific process of identifying abnormal transformation ratio of the current transformer based on the difference calculation result is as follows:

[0036] If all or If any item in the above is greater than a preset threshold, it is determined that the corresponding current transformer has a transformation ratio abnormality.

[0037] The present invention also provides an anti-disturbance current transformer ratio abnormality identification system, which is applied to the method described above, and the system comprises:

[0038] A data acquisition module, used to obtain the line loss in the target line and the electric energy increment corresponding to the energy supply transformer and the energy consumption transformer in the target line;

[0039] A solution module, used to establish an energy conservation matrix of a target line by using the line loss and the electric energy increment, and introduce an anti-disturbance parameter into the energy conservation matrix to build an objective function, wherein the objective function is used to solve a first transformation ratio of a current transformer corresponding to an energy supply transformer and a second transformation ratio of a current transformer corresponding to an energy consumption transformer by using a differentiated creative search algorithm;

[0040] The abnormality identification module is used to obtain the file transformation ratios of the current transformers corresponding to the energy supply transformer and the energy consumption transformer, calculate the differences between the first transformation ratio, the second transformation ratio and the corresponding file transformation ratios, and identify the abnormality of the transformation ratio of the current transformer based on the difference calculation results.

[0041] The technical solution of an anti-disturbance current transformer ratio abnormality identification method and system provided by the present invention has at least the following advantages and beneficial effects: (1) The present invention can quickly locate abnormal current transformers by calculating the ratios of all current transformers in the target line; (2) The present invention establishes an energy conservation matrix of the target line by using line loss and electric energy increment, introduces anti-disturbance parameters into the energy conservation matrix, constructs an objective function based on the energy conservation matrix, and uses a differentiated creative search algorithm to solve the ratio, which can effectively improve the stability of the ratio solution and reduce the accuracy loss caused by noise or numerical errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A flow chart of a disturbance-resistant current transformer ratio abnormality identification method provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Example 1

[0045] Figure 1 A schematic diagram of a flow chart of a method for identifying abnormal current transformer ratio with anti-disturbance provided by an embodiment of the present invention, the flow chart comprising the following steps:

[0046] S101: Determine the number of energy supply transformers and energy consumption transformers in the target line.

[0047] In this embodiment, the number of energy supply transformers in the target line is , the number of energy-consuming transformers is The energy supply transformer refers to the transformer that provides electrical energy and is managed by the power supply unit, and the power consumption transformer refers to the transformer that consumes electrical energy at the client end.

[0048] S102: Define the file transformation ratio of the current transformers corresponding to the energy supply transformer and the energy consumption transformer.

[0049] In this embodiment,

[0050] No. The file ratio of the voltage transformer corresponding to the power supply transformer is , ,in Indicates The file ratio of the voltage transformer corresponding to the energy supply transformer is The file ratio of the current transformer corresponding to the power transformer is ,in Indicates The file ratio of the power supply transformer to the current transformer; The file ratio of the voltage transformer corresponding to the energy-consuming transformer is , ,in Indicates The file ratio of the energy-consuming transformer to the voltage transformer is The file ratio of the current transformer corresponding to the energy-consuming transformer is ,in No. The energy-consuming transformer corresponds to the file ratio of the current transformer.

[0051] S103: Setting a data collection cycle, collecting the line loss in the target line and the electric energy increment corresponding to the energy supply transformer and the energy consumption transformer in the target line in each collection cycle.

[0052] In this embodiment, the data collection period is set to , the acquisition cycle The collection cycle is determined according to the number of energy supply transformers and energy consumption transformers in the target line. In each of the acquisition cycles The line loss in the target line and the electric energy increment corresponding to the energy supply transformer and the energy consumption transformer in the target line are collected, and the electric energy increment is determined according to the electric energy meter display value corresponding to the energy supply transformer and the energy consumption transformer; wherein the first The line loss in the target line during a collection cycle is ,in Indicates The line loss in the target line during the acquisition cycle, In the collection cycle The energy increment displayed by the energy meter corresponding to the energy supply transformer is , ,in Indicates In the collection cycle The energy increment displayed by the energy meter for each energy supply transformer is In the collection cycle The energy increment displayed by the energy meter for each energy-consuming transformer is ,in Indicates In the collection cycle The energy consumption transformer corresponds to the electric energy increment displayed by the electric energy meter.

[0053] S104: Using the line loss With electrical energy increment , Establish the energy conservation matrix of the target line.

[0054] The expression of the energy conservation matrix is ​​as follows:

[0055]

[0056]

[0057]

[0058]

[0059] In the above formula, The system matrix representing the energy supply transformer and the energy consumption transformer, Represents the transformation ratio matrix of the energy supply transformer and the energy consumption transformer, represents the line loss matrix, Indicates The first transformation ratio, i.e. The transformation ratio of the power transformer to the current transformer is: Indicates The first transformation ratio, Indicates The second transformation ratio, i.e. The transformation ratio of the energy-consuming transformer to the current transformer is: Indicates the second transformation ratio.

[0060] S105: In the energy conservation matrix The anti-disturbance parameter is introduced.

[0061] In this embodiment, by using the energy conservation matrix Introducing anti-disturbance parameters , establish a regularization matrix, the expression of the regularization matrix is ​​as follows:

[0062]

[0063] In the above formula, Representation Matrix The transposed matrix of arrive between, For the order The identity matrix of .

[0064] S106: First transformation ratio of the energy supply transformer to the current transformer The second transformation ratio of the current transformer corresponding to the energy-consuming transformer As a variable, an objective function based on the regularization matrix is ​​constructed, and the expression of the objective function is as follows:

[0065]

[0066] In the above formula, represents the second norm of the regularization matrix.

[0067] S107: Solve the objective function using a differentiated creative search algorithm to obtain the first transformation ratio of the current transformer corresponding to the energy transformer The second transformation ratio of the current transformer corresponding to the energy-consuming transformer .

[0068] It should be noted that the differentiated creative search (DCS) algorithm is a new meta-heuristic optimization method. The principle of the algorithm can be divided into the following three steps: Step 1, solution initialization; Step 2, differentiated knowledge acquisition; Step 3, convergent thinking; This algorithm adopts differentiated knowledge acquisition and creative realism strategies, has strong evolutionary ability, fast search speed and excellent optimization ability, and can solve the complex optimization problem of variable ratio solving.

[0069] It should be noted that the present invention can quickly locate abnormal current transformers by calculating the transformation ratio of all current transformers in the target line; in addition, by using line loss and electric energy increment to establish an energy conservation matrix of the target line, and introducing anti-disturbance parameters in the energy conservation matrix, an objective function based on the energy conservation matrix is ​​constructed, and a differentiated creative search algorithm is used to solve the transformation ratio, which can effectively improve the stability of the transformation ratio solution and reduce the accuracy loss caused by noise or numerical errors.

[0070] S108: Calculate the first transformation ratio respectively , Second Transformation Ratio The difference with the corresponding file ratio.

[0071] The expression for calculating the difference between the first transformation ratio and the corresponding file transformation ratio is as follows:

[0072]

[0073] In the above formula, Indicates The error limit of the current transformer corresponding to each power supply transformer;

[0074] The expression for calculating the difference between the second ratio and the corresponding file ratio is as follows:

[0075]

[0076] In the above formula, Indicates The error limit of the current transformer corresponding to each energy-consuming transformer.

[0077] S109: Identify abnormal transformation ratio of the current transformer based on the difference calculation result of step S108.

[0078] In this embodiment, if all or If all the current transformer ratios are less than or equal to the preset threshold, it is determined that all the current transformer ratios are normal, and the preset threshold is set to 0; or If any item is greater than the preset threshold, it is determined that the corresponding current transformer has an abnormal transformation ratio and further on-site inspection is required.

[0079] Example 2

[0080] This embodiment is based on the technical solution provided in Example 1 and provides a method applied to Example 1. The system includes:

[0081] A data acquisition module, used to obtain the line loss in the target line and the electric energy increment corresponding to the energy supply transformer and the energy consumption transformer in the target line;

[0082] A solution module, used to establish an energy conservation matrix of a target line by using the line loss and the electric energy increment, and introduce an anti-disturbance parameter into the energy conservation matrix to build an objective function, wherein the objective function is used to solve a first transformation ratio of a current transformer corresponding to an energy supply transformer and a second transformation ratio of a current transformer corresponding to an energy consumption transformer by using a differentiated creative search algorithm;

[0083] The abnormality identification module is used to obtain the file transformation ratios of the current transformers corresponding to the energy supply transformer and the energy consumption transformer, calculate the differences between the first transformation ratio, the second transformation ratio and the corresponding file transformation ratios, and identify the abnormality of the transformation ratio of the current transformer based on the difference calculation results.

[0084] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A disturbance-resistant current transformer ratio abnormality identification method, characterized in that: The following steps are involved: Obtaining line loss in a target line and electric energy increments corresponding to an energy supply transformer and an energy consumption transformer in the target line; The energy conservation matrix of the target line is established by using the line loss and the electric energy increment, and an anti-disturbance parameter is introduced into the energy conservation matrix to build an objective function, wherein the objective function is used to solve the first transformation ratio of the current transformer corresponding to the energy supply transformer and the second transformation ratio of the current transformer corresponding to the energy consumption transformer by using a differentiated creative search algorithm; Obtaining the file transformation ratios of the current transformers corresponding to the energy supply transformer and the energy consumption transformer, respectively calculating the differences between the first transformation ratio, the second transformation ratio and the corresponding file transformation ratios, and identifying abnormal transformation ratios of the current transformers based on the difference calculation results; The specific process of building the objective function is as follows: An anti-disturbance parameter is introduced into the energy conservation matrix to establish a regularization matrix. The expression of the regularization matrix is ​​as follows: In the above formula, The system matrix representing the energy supply transformer and the energy consumption transformer, Represents the transformation ratio matrix of the energy supply transformer and the energy consumption transformer, represents the line loss matrix, Representation Matrix The transposed matrix of is the anti-disturbance parameter, the value is arrive between, For the order The identity matrix of Build the objective function, the expression of the objective function is as follows: In the above formula, represents the second norm of the regularization matrix.

2. The anti-disturbance current transformer ratio abnormality identification method according to claim 1, characterized in that: The specific process of obtaining the line loss and electric energy increment is as follows: Set the collection period , the acquisition cycle Determined according to the number of energy supply transformers and energy consumption transformers in the target line; In each of the acquisition cycles The line loss in the target line and the electric energy increment corresponding to the energy supply transformer and the energy consumption transformer in the target line are collected.

3. The anti-disturbance current transformer ratio abnormality identification method according to claim 2, characterized in that: The electric energy increment is determined according to the electric energy meter display values ​​corresponding to the energy supply transformer and the energy consumption transformer.

4. The anti-disturbance current transformer ratio abnormality identification method according to claim 3, characterized in that: The expression of the energy conservation matrix is ​​as follows: In the above formula, Indicates In the collection cycle The energy increment displayed by the energy meter corresponds to the energy transformer. , ,in Indicates In the collection cycle The energy increment displayed by the energy meter corresponds to the energy transformer. Indicates the number of energy supply transformers in the target line, Indicates The file ratio of the power transformer corresponding to the voltage transformer is: Indicates The file ratio of the voltage transformer corresponding to the energy supply transformer is Indicates In the collection cycle The energy consumption transformer corresponds to the energy increment displayed by the energy meter. ,in Indicates In the collection cycle The energy consumption transformer corresponds to the energy increment displayed by the energy meter. Indicates the number of energy-consuming transformers in the target line, Indicates The energy-consuming transformer corresponds to the file ratio of the voltage transformer, where Indicates The file ratio of the voltage transformer corresponding to the energy-consuming transformer is: Indicates The first transformation ratio, wherein Indicates The first transformation ratio, Indicates The second transformation ratio is Indicates The second transformation ratio, Indicates The line loss in the target line during the acquisition cycle is Indicates The line loss in the target line during a collection period.

5. The anti-disturbance current transformer ratio abnormality identification method according to claim 4, characterized in that: The specific process of the difference calculation is as follows: Calculate the difference between the first ratio and the corresponding file ratio. The expression is as follows: In the above formula, No. The file ratio of the current transformer corresponding to the energy supply transformer is Indicates The error limit of the current transformer corresponding to each power supply transformer; Calculate the difference between the second ratio and the corresponding file ratio. The expression is as follows: In the above formula, No. The file ratio of the energy-consuming transformer to the current transformer is: Indicates The error limit of the current transformer corresponding to each energy-consuming transformer.

6. The anti-disturbance current transformer ratio abnormality identification method according to claim 5, characterized in that: The specific process of identifying abnormal transformation ratio of the current transformer based on the difference calculation result is as follows: If all or If any item in the above is greater than a preset threshold, it is determined that the corresponding current transformer has a transformation ratio abnormality.

7. A disturbance-resistant current transformer ratio abnormality identification system, characterized in that: Applied to the method according to any one of claims 1 to 6, the system comprises: A data acquisition module, used to obtain the line loss in the target line and the electric energy increment corresponding to the energy supply transformer and the energy consumption transformer in the target line; A solution module, used to establish an energy conservation matrix of a target line by using the line loss and the electric energy increment, and introduce an anti-disturbance parameter into the energy conservation matrix to build an objective function, wherein the objective function is used to solve a first transformation ratio of a current transformer corresponding to an energy supply transformer and a second transformation ratio of a current transformer corresponding to an energy consumption transformer by using a differentiated creative search algorithm; The abnormality identification module is used to obtain the file transformation ratios of the current transformers corresponding to the energy supply transformer and the energy consumption transformer, calculate the differences between the first transformation ratio, the second transformation ratio and the corresponding file transformation ratios, and identify the abnormality of the transformation ratio of the current transformer based on the difference calculation results.

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