Precision self-calibration method and system for current transformer

Abstract

The invention discloses a precision self-calibration method and system for a current transformer, and relates to the technical field of current transformer calibration, and the method comprises the steps: collecting and obtaining primary side current data, secondary side current data, a transformer environment data flow and a load change data flow; establishing a theoretical model of the current transformer, performing precision deviation evaluation on the primary side current data, the secondary side current data, the transformer environment data flow and the load change data flow based on the theoretical model of the current transformer, and determining precision deviation parameters of the current transformer; and carrying out calibration analysis on the current transformer precision deviation parameter based on a current transformer calibration strategy, determining a self-calibration correction parameter, and carrying out closed-loop self-calibration control on the target current mutual inductance. The technical effects of performing adaptive calibration on the current transformer in combination with various working condition factors, improving the reliability and stability of calibration of the current transformer and ensuring the measurement precision of the current transformer are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of current transformer calibration, and in particular to a precision self-calibration method and system for a current transformer. Background Art

[0002] Current transformers are essential devices for measurement and protection in power systems. They convert high currents into proportionally lower currents for use in measuring instruments and protective devices. However, the measurement accuracy of current transformers can be affected by a variety of factors, such as temperature, humidity, load variations, magnetic saturation, and aging after prolonged use.

[0003] Traditional current transformer calibration methods typically require specialized calibration equipment and operators, and must be performed in a specific calibration environment. This makes the calibration process cumbersome, time-consuming, and costly. Furthermore, traditional calibration methods cannot monitor and adjust the accuracy of the current transformer in real time. When the operating conditions of the current transformer change, its measurement accuracy may decrease, affecting the normal operation and protection of the power system. Therefore, a method that can perform real-time and intelligent current transformer calibration is needed to improve the measurement accuracy and reliability of current transformers and reduce calibration costs and maintenance difficulties. Summary of the Invention

[0004] The present application solves the technical problem that the measurement accuracy of the current transformer in the prior art is affected by the working conditions and the accuracy calibration is not reliable enough by providing a method and system for the accuracy self-calibration of the current transformer. It achieves the technical effect of adaptively calibrating the current transformer in combination with various working conditions, improving the reliability and stability of the current transformer calibration, and ensuring the measurement accuracy of the current transformer.

[0005] In view of the above problems, on the first aspect, the present application provides a method for self-calibration of the accuracy of a current transformer, the method comprising: respectively setting high-precision current sensors on the primary side and secondary side of the target current transformer, and acquiring the primary side current data and the secondary side current data in real time through the high-precision current sensors; using environmental monitoring equipment to acquire the transformer environmental data stream, and simultaneously monitoring and acquiring the load change data stream connected to the target current transformer; establishing a current transformer theoretical model, and performing accuracy deviation evaluation on the primary side current data and the secondary side current data, the transformer environmental data stream and the load change data stream based on the current transformer theoretical model, and determining the current transformer accuracy deviation parameter; constructing a current transformer calibration strategy, and performing calibration and analysis on the current transformer accuracy deviation parameter based on the current transformer calibration strategy, determining the self-calibration correction parameter, and performing closed-loop self-calibration control on the target current transformer through the self-calibration correction parameter.

[0006] On the other hand, the present application also provides an accuracy self-calibration system for current transformers, the system comprising: a data acquisition module, for setting high-precision current sensors on the primary and secondary sides of the target current transformer, respectively, and acquiring primary-side current data and secondary-side current data in real time through the high-precision current sensors; a data monitoring module, for acquiring the transformer environmental data stream using environmental monitoring equipment, and simultaneously monitoring and acquiring the load change data stream connected to the target current transformer; an accuracy evaluation module, for establishing a current transformer theoretical model, and performing accuracy deviation evaluation on the primary-side current data and secondary-side current data, the transformer environmental data stream and the load change data stream based on the current transformer theoretical model, to determine the current transformer accuracy deviation parameter; a self-calibration control module, for constructing a current transformer calibration strategy, and performing calibration and analysis on the current transformer accuracy deviation parameter based on the current transformer calibration strategy, determining the self-calibration correction parameter, and performing closed-loop self-calibration control on the target current transformer through the self-calibration correction parameter.

[0007] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0008] By adopting the real-time acquisition of the primary and secondary current data of the target current transformer, as well as the transformer environment data stream and the load change data stream, a current transformer theoretical model is established to perform accuracy deviation assessment on the primary and secondary current data, the transformer environment data stream, and the load change data stream, determine the current transformer accuracy deviation parameters, and then calibrate and analyze the current transformer accuracy deviation parameters based on the current transformer calibration strategy to determine the self-calibration correction parameters. Based on this technical solution, closed-loop self-calibration control of the target current transformer is performed. This achieves the technical effect of adaptively calibrating the current transformer in combination with multiple working conditions, improving the reliability and stability of the current transformer calibration, and ensuring the measurement accuracy of the current transformer.

[0009] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a flow chart of the accuracy self-calibration method for a current transformer according to the present application.

[0011] Figure 2 This is a schematic diagram of the structure of the accuracy self-calibration system for current transformers used in this application.

[0012] Description of reference numerals: data acquisition module 11 , data monitoring module 12 , accuracy assessment module 13 , self-calibration control module 14 . DETAILED DESCRIPTION

[0013] The present application solves the technical problem that the measurement accuracy of the current transformer in the prior art is affected by the working conditions and the accuracy calibration is not reliable enough by providing a method and system for the accuracy self-calibration of the current transformer. It achieves the technical effect of adaptively calibrating the current transformer in combination with various working conditions, improving the reliability and stability of the current transformer calibration, and ensuring the measurement accuracy of the current transformer.

[0014] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0015] The present application is described below in conjunction with the accompanying drawings.

[0016] Example 1, as Figure 1 As shown, the present application provides a method for self-calibration of the accuracy of a current transformer, the method comprising:

[0017] Step S100: high-precision current sensors are respectively provided on the primary side and the secondary side of the target current transformer, and primary-side current data and secondary-side current data are acquired in real time by the high-precision current sensors.

[0018] Step S200: using environmental monitoring equipment to collect and acquire transformer environmental data streams, while monitoring and collecting load change data streams connected to the target current transformer.

[0019] Specifically, current transformers are crucial devices for measurement and protection in power systems. They convert high currents proportionally to lower currents, facilitating the use of measuring instruments and protective devices. To achieve self-calibration of the current transformer's accuracy, first install high-precision current sensors on both the primary and secondary sides of the target current transformer. Select a high-precision current sensor with an appropriate range and accuracy based on the rated current range, accuracy requirements, and other parameters of the target current transformer. For example, if the target current transformer measures currents from 0 to 1000A and requires an accuracy of 0.1%, select a high-precision current sensor with a range of 1000A and an accuracy better than 0.1%. Install the selected high-precision current sensors on both the primary and secondary sides of the target current transformer, ensuring secure installation and reliable connections to avoid measurement errors caused by poor contact. Connect the output signals of the high-precision current sensors to a data acquisition system. Set the sampling frequency of the data acquisition system, determining the appropriate sampling frequency based on the speed of current change and the accuracy requirements. For example, for rapidly changing currents, the sampling frequency may need to be several kilohertz or higher; for slower-changing currents, the sampling frequency can be set to several hundred kilohertz. At the same time, the trigger mode and storage mode of data acquisition are set to ensure that the current data of the primary and secondary sides can be collected in real time and accurately.

[0020] Based on monitoring requirements, select environmental monitoring equipment that can accurately measure environmental parameters such as temperature, humidity, and electromagnetic interference. For example, use a high-precision temperature and humidity sensor to monitor temperature and humidity, and an electromagnetic field strength meter to monitor electromagnetic interference. Install the environmental monitoring equipment in a suitable location near the target current transformer to ensure it accurately captures data about the transformer's environment. Connect the output signal of the environmental monitoring equipment to the data acquisition system, and set an appropriate sampling frequency to collect environmental data streams. For example, if temperature and humidity change relatively slowly, the sampling frequency can be set to every minute or every few minutes; however, if electromagnetic interference changes more rapidly, the sampling frequency can be increased appropriately. Select appropriate equipment such as ammeters and voltmeters to monitor changes in the load connected to the target current transformer. Connect the measurement signal of the load monitoring equipment to the data acquisition system, and set the sampling frequency to monitor the load change data stream. Determine an appropriate sampling frequency based on the characteristics of the load changes, such as whether the load switches frequently. If the load changes rapidly, the sampling frequency needs to be increased to capture the load changes in a timely manner. Real-time collection of primary and secondary current data, transformer environmental data streams, and load change data streams is required for subsequent accuracy calibration, analysis, and processing.

[0021] Step S300: establishing a current transformer theoretical model, and performing accuracy deviation evaluation on the primary side current data, the secondary side current data, the transformer environment data stream, and the load change data stream based on the current transformer theoretical model to determine a current transformer accuracy deviation parameter.

[0022] Furthermore, the steps of establishing the current transformer theoretical model in this application also include:

[0023] A current transformer test parameter table is obtained, and a test record of a calibrated current transformer is performed based on the current transformer test parameter table to obtain a current transformer working data set; abnormal data is identified on the current transformer working data set according to a data application standard to obtain an abnormal working data set; an abnormal data cleaning program is set, and the abnormal data cleaning program is used to clean the abnormal working data set to obtain a standard current transformer working data set; theoretical current identification training is performed on the standard current transformer working data set to obtain a current transformer theoretical model.

[0024] Furthermore, the steps of obtaining the current transformer test parameter table in this application also include:

[0025] Obtain current transformer accuracy-related factors, where the current transformer accuracy-related factors include current parameters, environmental parameters, and load parameters; design test parameters for each of the current transformer accuracy-related factors according to the current transformer application scenario to obtain a current transformer test factor parameter set; and orthogonally arrange the current transformer test factor parameter set to obtain the current transformer test parameter table.

[0026] Furthermore, the steps of obtaining the current transformer theoretical model in this application also include:

[0027] The secondary side current of the standard current transformer working data set is extracted and identified to obtain theoretical secondary side current data; the current transformer test factor parameter set is used as an input independent variable and the theoretical secondary side current data is used as an output dependent variable for correlation fitting training to generate an initial current transformer model; the initial current transformer model is verified and optimized according to the model application standard to obtain the current transformer theoretical model.

[0028] Specifically, based on the working principle of the current transformer and actual operating experience, the factors related to the accuracy of the current transformer are clarified, including current parameters (such as current magnitude, frequency, waveform distortion rate, etc.), environmental parameters (such as temperature, humidity, electromagnetic interference intensity, etc.) and load parameters (such as load type, load impedance variation range, etc.). According to the application scenario of the current transformer, the test parameters of each of the related factors in the current transformer accuracy are designed. For the current parameters, based on the common application scenarios of the current transformer (such as industrial production, power system, etc.), the current magnitude range (such as 0-120% of the rated current), frequency range (such as 50Hz±5% and other common industrial frequencies and their harmonic frequencies), and typical waveform distortion rate conditions (such as considering different levels of harmonic content such as 5% and 10%) are determined in different scenarios. For environmental parameters, according to the possible working environment of the current transformer, the temperature range (such as -40℃-+85℃ and other different industrial environment temperature ranges), humidity range (such as 10%-95%RH), and electromagnetic interference intensity range (refer to relevant electromagnetic compatibility standards to determine different levels of interference intensity) are set. In terms of load parameters, determine the common load types (such as resistive load, inductive load, capacitive load and their combination loads), as well as the range of change of load impedance during normal operation (such as ±10%, ±20%, etc.). Through the above design, the current transformer test factor parameter set is obtained. The parameters in the current transformer test factor parameter set are orthogonally arranged. According to the number of parameters and the number of levels, a suitable orthogonal table is selected to ensure that the different levels of each parameter can be evenly matched in the test, reducing the number of tests while ensuring the representativeness of the test results, thereby obtaining the current transformer test parameter table.

[0029] Build a professional test platform according to the current transformer test parameter table. Prepare high-precision test equipment, such as a standard current source, high-precision temperature sensor, humidity sensor, electromagnetic field intensity meter, and load simulator, to ensure that the test equipment meets the required accuracy and stability. Connect the calibrated current transformer to the test platform and test it sequentially according to the parameter combinations in the test parameter table. At each test point, record data such as the primary current, secondary current, ambient temperature, humidity, electromagnetic interference intensity, and load impedance when meeting the application requirements to form a current transformer working data set. During the testing process, strictly control the test conditions to ensure the accuracy of each test. Establish data application standards to clarify the reasonable range and variation patterns of each parameter. For example, for current data, set the upper and lower current limits based on the current transformer's rated parameters and normal operating range. For temperature data, set a reasonable temperature fluctuation range based on the current transformer's temperature characteristics.

[0030] Establish data application standards to clarify the reasonable range and variation patterns of each parameter. For example, for current data, set upper and lower current limits based on the rated parameters and normal operating range of the current transformer. For temperature data, set a reasonable temperature fluctuation range based on the temperature characteristics of the current transformer. Identify abnormal data in the current transformer working dataset according to the data application standards. When data exceeds the set reasonable range or exhibits conditions that do not conform to the variation pattern (such as sudden, large current fluctuations without a reasonable cause), it is determined to be abnormal data, resulting in an abnormal working dataset. Establish an abnormal data cleaning procedure based on the characteristics of the abnormal data. Clearly erroneous data (such as data outside the device's range) is directly eliminated. Data deviations caused by accidental interference can be corrected using interpolation methods (such as linear interpolation and polynomial interpolation). For consecutive abnormal data segments, analyze their possible causes. If it is determined to be caused by equipment failure or sudden changes in the test environment, eliminate the entire segment. Use the cleaning procedure to process the abnormal working dataset to obtain a standard current transformer working dataset for subsequent traceability and verification.

[0031] Conduct theoretical current identification training on the standard current transformer working data set. Utilizing the known working principles and theoretical formulas of current transformers, combined with actual test data, conduct theoretical analysis and identification of the current data in the data set to provide an accurate reference for subsequent model training. Extract secondary current data from the standard current transformer working data set and identify it. Use the extracted secondary current data as the target data for subsequent model training. Select a multivariate regression model, use the current transformer test factor parameter set as the input independent variable, and the theoretical secondary current data as the output dependent variable, and conduct association fitting training. During the training process, adjust the model parameters and structure so that the model can accurately describe the relationship between the input independent variable and the output dependent variable. Generate an initial current transformer model through multiple iterative training.

[0032] Prepare a validation dataset in accordance with the model application standard. The validation dataset should be independent of the training dataset and representative. Use the validation dataset to validate the initial current transformer model and calculate the model's prediction error (such as mean square error and mean absolute error). Based on the validation results, adjust the model's parameters, structure, or algorithm, and retrain and validate. Repeat this process until the model's prediction error meets the requirements of the model application standard, and the current transformer theoretical model is obtained. This model can accurately predict the theoretical value of the secondary current based on input current parameters, environmental parameters, and load parameters, providing a benchmark for evaluating current transformer accuracy deviations. It also forms the core basis of the calibration strategy. By comparing it with actual data, it helps determine the self-calibration correction parameters and achieve self-calibration of current transformer accuracy.

[0033] Furthermore, the step of determining the current transformer accuracy deviation parameter in this application further includes:

[0034] The primary side current data, the transformer environment data stream and the load change data stream are input into the current transformer theoretical model for analysis, and a target secondary side current theoretical value is output; a secondary side current deviation value of the secondary side current data and the target secondary side current theoretical value is calculated and obtained; a relative accuracy deviation evaluation is performed on the secondary side current deviation value to determine the current transformer accuracy deviation parameter.

[0035] Specifically, a current transformer theoretical model is run, and the primary current data, the transformer environment data stream, and the load change data stream are input into the current transformer theoretical model for analysis, outputting a corresponding target secondary current theoretical value. A secondary current deviation value is then calculated between the secondary current data and the target secondary current theoretical value. Based on the calculated secondary current deviation value, a relative accuracy deviation is calculated. The formula for calculating the relative accuracy deviation can be selected based on actual conditions; a common formula is: relative accuracy deviation = (secondary current deviation value / target secondary current theoretical value) × 100%. The relative accuracy deviation sequence is analyzed according to data application standards and accuracy requirements. For example, statistics such as the average, maximum, minimum, and standard deviation of the relative accuracy deviation can be calculated to comprehensively assess the accuracy deviation of the current transformer. Based on the analysis results, current transformer accuracy deviation parameters are determined. Accuracy deviation parameters may include average relative accuracy deviation and maximum relative accuracy deviation, and these parameters serve as the basis for subsequent current transformer calibration.

[0036] Step S400: constructing a current transformer calibration strategy, performing calibration analysis on the current transformer accuracy deviation parameter based on the current transformer calibration strategy, determining a self-calibration correction parameter, and performing closed-loop self-calibration control on the target current transformer using the self-calibration correction parameter.

[0037] Furthermore, the step of determining the self-calibration correction parameter in this application further includes:

[0038] The causes of the deviation of the current transformer accuracy deviation parameters are analyzed to determine the causes of the current transformer accuracy deviation; strategy matching is performed on the causes of the current transformer accuracy deviation based on the current transformer calibration strategy to obtain a target accuracy calibration strategy; the current transformer accuracy deviation parameters are calibrated and analyzed using the target accuracy calibration strategy to determine self-calibration correction parameters.

[0039] Furthermore, the step of determining the self-calibration correction parameter in this application further includes:

[0040] Based on the target precision calibration strategy, associated data mining and calibration model fitting are performed to construct a target precision calibration model; the target precision calibration model is used to calibrate and calculate the current transformer precision deviation parameter to determine the self-calibration correction parameter.

[0041] Specifically, based on the working principle of the current transformer, common types of accuracy deviation and actual application scenarios, the overall framework of the calibration strategy is designed, and various common causes of accuracy deviation and their corresponding calibration strategies are organized into a strategy library. The strategy library should contain detailed strategy descriptions, applicable conditions, operating steps and expected results. For example, for deviations caused by temperature, the strategy library should record the specific implementation method of the temperature compensation calibration strategy, including the calculation method of the temperature compensation coefficient, the connection method of the compensation circuit, etc. Based on the current transformer calibration strategy, the accuracy deviation parameters of the current transformer are calibrated and analyzed. First, the causes of the deviation of the accuracy deviation parameters of the current transformer are analyzed. According to the working principle of the current transformer and common failure modes, the accuracy deviation parameters are preliminarily analyzed. For example, if the deviation increases significantly when the temperature rises, it is preliminarily judged that it may be related to the influence of temperature; if the deviation changes regularly when the load changes, it may be caused by the load characteristics.

[0042] According to the determined cause of the current transformer accuracy deviation, a matching search is performed in the strategy library, and the calibration strategy that best suits the current deviation cause is selected as the target accuracy calibration strategy. In the matching process, factors such as the severity of the deviation, the feasibility of calibration and the cost are considered. The target accuracy calibration strategy is used to calibrate and analyze the current transformer accuracy deviation parameters, and associated data mining is performed based on the target accuracy calibration strategy to mine data related to the current transformer accuracy deviation. In addition to the primary side current, secondary side current, environmental data and load data in the aforementioned steps, the historical operating data and maintenance records of the transformer can also be considered. Use data mining algorithms (such as association rule mining, cluster analysis, etc.) to find the relationship between the accuracy deviation parameters and their calibration parameters. Select a suitable mathematical model or machine learning algorithm (such as regression analysis, neural network, etc.), use the accuracy deviation parameters as input and the accuracy calibration parameters as output, and perform calibration model fitting. In the fitting process, adjust the parameters and structure of the model so that the model can accurately describe the relationship between the input data and the output parameters, until the fitting accuracy of the model meets the requirements, and obtain the target accuracy calibration model. The target accuracy calibration model is used to perform calibration calculation on the accuracy deviation parameter of the current transformer, and a self-calibration correction parameter corresponding to the accuracy deviation parameter is determined.

[0043] The target current transformer is subjected to closed-loop self-calibration control using the self-calibration correction parameters. The self-calibration correction parameters are applied to the current transformer's measurement system, allowing the transformer to automatically perform corrections during the measurement process. A closed-loop self-calibration control system is established to monitor the current transformer's measurement data and accuracy deviations in real time. The corrected measurement data is compared with the standard value. If a deviation still exists, the calibration process is triggered again, and the self-calibration correction parameters are updated to achieve closed-loop self-calibration control of the current transformer. During the closed-loop control process, the calibration system must be regularly inspected and maintained to improve the reliability and stability of the current transformer calibration, thereby ensuring the current transformer's measurement accuracy.

[0044] In summary, the accuracy self-calibration method for current transformers provided in this application has the following technical effects:

[0045] By adopting the real-time acquisition of the primary and secondary current data of the target current transformer, as well as the transformer environment data stream and the load change data stream, a current transformer theoretical model is established to perform accuracy deviation assessment on the primary and secondary current data, the transformer environment data stream, and the load change data stream, determine the current transformer accuracy deviation parameters, and then calibrate and analyze the current transformer accuracy deviation parameters based on the current transformer calibration strategy to determine the self-calibration correction parameters. Based on this technical solution, closed-loop self-calibration control of the target current transformer is performed. This achieves the technical effect of adaptively calibrating the current transformer in combination with multiple working conditions, improving the reliability and stability of the current transformer calibration, and ensuring the measurement accuracy of the current transformer.

[0046] In the second embodiment, based on the same inventive concept as the accuracy self-calibration method for current transformers in the above embodiment, the present invention also provides an accuracy self-calibration system for current transformers, such as Figure 2 As shown, the system includes:

[0047] The data acquisition module 11 is used to respectively set high-precision current sensors on the primary side and the secondary side of the target current transformer, and acquire the primary side current data and the secondary side current data in real time through the high-precision current sensors.

[0048] The data monitoring module 12 is used to collect and obtain the transformer environment data stream using environmental monitoring equipment, and simultaneously monitor and collect the load change data stream connected to the target current transformer.

[0049] The accuracy evaluation module 13 is used to establish a current transformer theoretical model, and perform accuracy deviation evaluation on the primary side current data and the secondary side current data, the transformer environment data stream and the load change data stream based on the current transformer theoretical model to determine the current transformer accuracy deviation parameter.

[0050] The self-calibration control module 14 is used to construct a current transformer calibration strategy, calibrate and analyze the current transformer accuracy deviation parameters based on the current transformer calibration strategy, determine self-calibration correction parameters, and perform closed-loop self-calibration control on the target current transformer using the self-calibration correction parameters.

[0051] Furthermore, the accuracy assessment module 13 is further configured to perform the following steps:

[0052] A current transformer test parameter table is obtained, and a test record of a calibrated current transformer is performed based on the current transformer test parameter table to obtain a current transformer working data set; abnormal data is identified on the current transformer working data set according to a data application standard to obtain an abnormal working data set; an abnormal data cleaning program is set, and the abnormal data cleaning program is used to clean the abnormal working data set to obtain a standard current transformer working data set; theoretical current identification training is performed on the standard current transformer working data set to obtain a current transformer theoretical model.

[0053] Furthermore, the accuracy assessment module 13 is further configured to perform the following steps:

[0054] Obtain current transformer accuracy-related factors, where the current transformer accuracy-related factors include current parameters, environmental parameters, and load parameters; design test parameters for each of the current transformer accuracy-related factors according to the current transformer application scenario to obtain a current transformer test factor parameter set; and orthogonally arrange the current transformer test factor parameter set to obtain the current transformer test parameter table.

[0055] Furthermore, the accuracy assessment module 13 is further configured to perform the following steps:

[0056] The secondary side current of the standard current transformer working data set is extracted and identified to obtain theoretical secondary side current data; the current transformer test factor parameter set is used as an input independent variable and the theoretical secondary side current data is used as an output dependent variable for correlation fitting training to generate an initial current transformer model; the initial current transformer model is verified and optimized according to the model application standard to obtain the current transformer theoretical model.

[0057] Furthermore, the accuracy assessment module 13 is further configured to perform the following steps:

[0058] The primary side current data, the transformer environment data stream and the load change data stream are input into the current transformer theoretical model for analysis, and a target secondary side current theoretical value is output; a secondary side current deviation value of the secondary side current data and the target secondary side current theoretical value is calculated and obtained; a relative accuracy deviation evaluation is performed on the secondary side current deviation value to determine the current transformer accuracy deviation parameter.

[0059] Furthermore, the self-calibration control module 14 is further configured to perform the following steps:

[0060] The causes of the deviation of the current transformer accuracy deviation parameters are analyzed to determine the causes of the current transformer accuracy deviation; strategy matching is performed on the causes of the current transformer accuracy deviation based on the current transformer calibration strategy to obtain a target accuracy calibration strategy; the current transformer accuracy deviation parameters are calibrated and analyzed using the target accuracy calibration strategy to determine self-calibration correction parameters.

[0061] Furthermore, the self-calibration control module 14 is further configured to perform the following steps:

[0062] Based on the target precision calibration strategy, associated data mining and calibration model fitting are performed to construct a target precision calibration model; the target precision calibration model is used to calibrate and calculate the current transformer precision deviation parameter to determine the self-calibration correction parameter.

[0063] The foregoing Figure 1 The various variations and specific examples of the precision self-calibration method for current transformers in Example 1 are also applicable to the precision self-calibration system for current transformers in this embodiment. Through the above detailed description of the precision self-calibration method for current transformers, those skilled in the art can clearly understand the implementation method of the precision self-calibration system for current transformers in this embodiment, so for the sake of brevity of the specification, they will not be described in detail here.

[0064] This specification and the accompanying drawings are merely exemplary illustrations of the present application, but the scope of protection of the present application is not limited thereto. It should be noted that any person skilled in the art can easily conceive of changes or replacements within the technical scope disclosed in this application, which should all be included in the scope of protection of this application. In some cases, the actions or steps described in this application can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for self-calibrating the accuracy of a current transformer, characterized in that: The method comprises: High-precision current sensors are respectively provided on the primary side and the secondary side of the target current transformer, and the primary side current data and the secondary side current data are acquired in real time by the high-precision current sensors; Using environmental monitoring equipment to collect and acquire transformer environmental data streams, while monitoring and collecting load change data streams connected to the target current transformer; Establishing a current transformer theoretical model, and performing accuracy deviation evaluation on the primary-side current data, the secondary-side current data, the transformer environment data stream, and the load change data stream based on the current transformer theoretical model to determine a current transformer accuracy deviation parameter; A current transformer calibration strategy is constructed, and based on the current transformer calibration strategy, the current transformer accuracy deviation parameter is calibrated and analyzed, a self-calibration correction parameter is determined, and closed-loop self-calibration control of the target current transformer is performed using the self-calibration correction parameter.

2. The accuracy self-calibration method for current transformer according to claim 1, characterized in that: The method of establishing a current transformer theoretical model includes: Obtaining a current transformer test parameter table, performing test records on a calibrated current transformer based on the current transformer test parameter table, and obtaining a current transformer working data set; performing abnormal data identification on the current transformer working data set according to a data application standard to obtain an abnormal working data set; Setting an abnormal data cleaning program, using the abnormal data cleaning program to clean the abnormal working data set to obtain a standard current transformer working data set; Theoretical current identification training is performed on the standard current transformer working data set to obtain a current transformer theoretical model.

3. The accuracy self-calibration method for a current transformer according to claim 2, characterized in that: The step of obtaining a current transformer test parameter table includes: Acquiring current transformer accuracy-related factors, where the current transformer accuracy-related factors include current parameters, environmental parameters, and load parameters; Designing test parameters for each of the current transformer accuracy-related factors according to the current transformer application scenario to obtain a current transformer test factor parameter set; The current transformer test factor parameter set is orthogonally arranged to obtain the current transformer test parameter table.

4. The accuracy self-calibration method for a current transformer according to claim 3, characterized in that: The obtaining of the current transformer theoretical model comprises: Performing secondary side current extraction and identification on the standard current transformer working data set to obtain theoretical secondary side current data; Using the current transformer test factor parameter set as input independent variables and the theoretical secondary side current data as output dependent variables to perform correlation fitting training to generate an initial current transformer model; The initial current transformer model is verified and optimized according to the model application standard to obtain the current transformer theoretical model.

5. The accuracy self-calibration method for current transformer according to claim 1, characterized in that: Determining the current transformer accuracy deviation parameter includes: Inputting the primary side current data, the transformer environment data stream, and the load change data stream into the current transformer theoretical model for analysis, and outputting a target secondary side current theoretical value; Calculating and obtaining a secondary-side current deviation value between the secondary-side current data and the target secondary-side current theoretical value; A relative accuracy deviation evaluation is performed on the secondary side current deviation value to determine the current transformer accuracy deviation parameter.

6. The accuracy self-calibration method for current transformer according to claim 1, characterized in that: The determining of the self-calibration correction parameter comprises: Analyzing the causes of the deviation of the current transformer accuracy deviation parameters to determine the causes of the current transformer accuracy deviation; Performing strategy matching on causes of current transformer accuracy deviation based on the current transformer calibration strategy to obtain a target accuracy calibration strategy; The target accuracy calibration strategy is adopted to calibrate and analyze the accuracy deviation parameters of the current transformer to determine the self-calibration correction parameters.

7. The accuracy self-calibration method for a current transformer according to claim 6, characterized in that: The determining of the self-calibration correction parameter comprises: Performing associated data mining and calibration model fitting based on the target precision calibration strategy to construct a target precision calibration model; The target accuracy calibration model is used to perform calibration calculation on the current transformer accuracy deviation parameter to determine the self-calibration correction parameter.

8. A precision self-calibration system for current transformers, characterized in that: For implementing the accuracy self-calibration method for a current transformer according to any one of claims 1 to 7, the system comprises: A data acquisition module is configured to respectively set high-precision current sensors on the primary side and the secondary side of the target current transformer, and acquire primary-side current data and secondary-side current data in real time through the high-precision current sensors; A data monitoring module is used to collect and obtain the transformer environment data stream using environmental monitoring equipment, and simultaneously monitor and collect the load change data stream connected to the target current transformer; an accuracy evaluation module, configured to establish a current transformer theoretical model, and perform accuracy deviation evaluation on the primary and secondary current data, the transformer environment data stream, and the load change data stream based on the current transformer theoretical model to determine a current transformer accuracy deviation parameter; The self-calibration control module is used to construct a current transformer calibration strategy, calibrate and analyze the current transformer accuracy deviation parameters based on the current transformer calibration strategy, determine self-calibration correction parameters, and perform closed-loop self-calibration control on the target current transformer using the self-calibration correction parameters.

Images