Multi-dimensional parameter adjustable current transformer error characteristic evaluation platform and method

Abstract

The application discloses a multi-dimensional parameter adjustable current transformer error characteristic evaluation platform and method, relates to the technical field of power systems and electrical engineering, and comprises a power supply unit, a control display unit, a standard value test unit, an environment control unit, an error adjustable current transformer group, a transformer calibrator, a current transformer measurement performance online monitoring device and a user interface. The application discloses a multi-dimensional parameter adjustable current transformer error characteristic evaluation test platform design method, which greatly improves the diversity, accuracy and reliability of current transformer error characteristic evaluation tests, can realize error characteristic evaluation accuracy tests on the current transformer measurement performance online monitoring device, can be used for developing a current transformer operation error evaluation model, provides a large amount of data for model training, and has extremely high scientific research value and detection value.

Description

Technical Field

[0001] This invention relates to the technical field of power systems and electrical engineering, specifically to a multi-dimensional parameter adjustable current transformer error characteristic evaluation platform and method. Background Technology

[0002] High-voltage current transformers are used to convert large primary currents into smaller currents according to a set ratio for use in metering, measurement, and protection equipment. The signal from the metering winding of a high-voltage current transformer is connected to a gate meter, and the accuracy of this signal directly affects the fairness of electricity trade settlement, making it extremely important. After long-term operation, a small number of current transformers may experience errors exceeding the error limit in their metering windings. These transformers require further manual fault assessment. Traditionally, the method for assessing anomalies in the metering windings of current transformers involves comparing the secondary signals of a standard current transformer with those of a current transformer with the same rated transformation ratio under offline conditions during a power outage. However, this offline error detection method deviates from the actual operating environment of the current transformers, resulting in some current transformers exhibiting errors exceeding the limit during operation, making it impossible to detect out-of-tolerance events in a timely manner. To accurately and promptly detect the metering status of operating current transformers and obtain accurate information on their operational errors, online monitoring technology for current transformer errors has become a hot topic and a challenge in the development of electricity metering devices.

[0003] In exploring online monitoring technology for current transformer errors, domestic and international scholars have mainly focused on research based on wavelet fractal theory and clustering radial basis functions. To assess the accuracy of such models, scholars primarily use computers to automatically generate random data, then employ neural networks to divide the data into training and test sets, and finally evaluate the accuracy of current transformer error assessment from a computer analysis perspective. However, the randomly generated samples differ significantly from the data of high-voltage current transformers actually operating in power plants; therefore, a testing platform specifically for current transformer error assessment models has not yet emerged. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by this invention is: how to build a multi-dimensional parameter adjustable current transformer error characteristic evaluation platform, which greatly improves the diversity, accuracy and reliability of current transformer error characteristic evaluation tests, and realizes the accuracy test of error characteristic evaluation of online monitoring device for current transformer metering performance.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a multi-dimensional parameter adjustable current transformer error characteristic evaluation platform, which includes the following steps: a power supply unit, a control and display unit, a standard value testing unit, an environmental control unit, an error adjustable current transformer group, a transformer calibrator, an online monitoring device for current transformer metering performance, and a user interface. The power supply unit provides power to the entire system and is connected to all modules that require power. The control and display unit is responsible for integrating the system's operating status and results, and displaying detailed operating data and analysis results to the user through a high-definition display screen. The standard value testing unit is responsible for providing standard values, including the standard error value and standard current value of the current transformer; The environmental control unit is responsible for monitoring and adjusting the system's operating environment, including temperature, humidity, and electromagnetic interference, so that the system operates under optimal environmental conditions. The error-adjustable current transformer group adjusts the error of the current transformer; The current transformer calibrator is responsible for calibrating the performance of the current transformer. Through precise testing instruments, it accurately measures the error and current value of the current transformer and sends the test results to the online monitoring device for current transformer metering performance for further analysis. The online monitoring device for metering performance of current transformers is responsible for monitoring the performance of current transformers. It collects real-time data of the metering windings of operating current transformers at high frequency and performs a comprehensive analysis of the performance of current transformers. The user interface is responsible for interacting with the user and receiving user input. Through input devices such as touch screens or buttons, users can set system operating parameters, query operating data and analysis results. At the same time, the system's operating status and results will also be displayed to the user on the screen.

[0007] As a preferred embodiment of the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform described in this invention, the control display unit is connected to the user interface module, the power supply unit, and the environmental control unit. The control display unit receives input signals from the user interface module to realize human-computer interaction, obtains stable power from the power supply unit to determine its normal operation, and adjusts the brightness, contrast, etc. of the display screen according to the environmental parameters provided by the environmental control unit to ensure clear display under different environmental conditions.

[0008] The control and display unit includes a data display submodule, a human-computer interaction submodule, and a data processing submodule.

[0009] The data display submodule is responsible for displaying the system's operating data and analysis results on a high-definition display screen in the form of charts, text, etc., so that users can intuitively understand the system's operating status and results.

[0010] The human-computer interaction submodule is responsible for receiving input signals from the user interface and realizing human-computer interaction functions. Users can interact with the system through input devices such as touch screens and buttons, set system operating parameters, and query operating data and analysis results.

[0011] The data processing submodule is responsible for processing user input, transmitting user operation instructions to the corresponding modules, implementing system control functions, and processing system operation data and analysis results, converting them into a form that users can understand.

[0012] As a preferred embodiment of the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform of the present invention, the standard value test unit is connected to the parameter input module and the power supply unit, receives the basic parameters provided by the sub-module parameter input module of the user interface module, calculates the standard performance value of the current transformer, compares it with the actual measured value, evaluates the performance of the current transformer, and obtains the error of the current transformer. The basic parameters include the rated current and rated voltage of the current transformer and the amplitude of the current signal. The parameter input module converts the input data into the format required by the system and transmits it to the standard value test unit for processing. The standard value testing unit includes a parameter receiving module, a data processing module, and a performance evaluation module; The parameter receiving module receives the basic parameters provided by the parameter input module; The data processing module converts the received basic parameters into the format required by the system and establishes an equation between the primary and secondary currents, the expression of which is:

[0013] in, This represents the effective value of the amplitude of the standard current signal. The effective value of the amplitude of the detected current signal. The initial phase angle of the standard current signal. The initial phase angle of the detected current signal is denoted as . The primary current of the first current transformer. This refers to the secondary current of the first current transformer. Rated current ratio The ratio difference of the first current transformer. The phase difference is the phase difference of the first current transformer.

[0014] The performance evaluation module compares the calculated standard values ​​with the actual measured values ​​to evaluate the performance of the current transformer.

[0015] As a preferred embodiment of the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform described in this invention, the environmental control unit is connected to the power supply unit, the transformer calibrator, and the online monitoring device for current transformer metering performance via sensors and a controller. The sensors of the environmental control unit are responsible for monitoring the environmental conditions of the system operation, including temperature and humidity, and transmitting the monitored environmental data to the controller for processing. The controller analyzes the environmental data according to preset standard values ​​and determines whether the environmental conditions need to be adjusted.

[0016] The environmental control unit also includes a temperature control module and a humidity control module. If the environmental conditions do not meet the preset standard values, the controller will send a control signal to the power supply unit to start the corresponding adjustment device and adjust the environmental conditions to a suitable range. If the adjusted environmental parameters still do not meet the preset standard values, the environmental control unit will send an abnormal signal to the control display unit, which will then issue a warning to the user interface module to notify the user to take further measures.

[0017] As a preferred embodiment of the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform described in this invention, the error adjustable current transformer group is connected to the current transformer calibrator. The error adjustable current transformer group receives current transformer performance data transmitted from the current transformer calibrator, adjusts the error of the current transformer according to the data, and then transmits the adjusted error data to the current transformer calibrator. The current transformer calibrator recalibrates the performance of the current transformer according to the adjusted error data and determines whether the performance of the current transformer meets the preset standard. The performance verification of the current transformer includes verification of the rated current ratio, phase difference, phase difference, and environmental factors. If the rated current ratio, phase difference, or ratio difference does not meet the set threshold, the current transformer calibrator sends an adjustment command and the actual rated current ratio, phase difference, or ratio difference to the error adjustable current transformer group, and the error adjustable current transformer group adjusts the rated current ratio, phase difference, or ratio difference between the primary current and secondary current of the current transformer. If environmental factors do not meet the requirements, the current transformer calibrator sends an adjustment command to the environmental control unit, which then adjusts the environmental conditions for system operation to determine whether the current transformer's performance remains stable under different environmental conditions such as temperature and humidity.

[0018] As a preferred embodiment of the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform described in this invention, the current transformer calibrator is connected to the online monitoring device for current transformer metering performance. The current transformer calibrator receives real-time performance data of the current transformer transmitted by the online monitoring device for current transformer metering performance. Based on the received data, the current transformer calibrator verifies the performance of the current transformer and determines whether its performance meets the preset standard. If the verification result shows that the performance of the current transformer does not meet the standard, the current transformer calibrator will transmit this information to the error-adjustable current transformer group, which will then adjust the error.

[0019] The error-adjustable current transformer group includes multiple current transformers, each with an adjustment device that can adjust the ratio between the primary and secondary currents of the current transformer, thereby further adjusting the error of the current transformer.

[0020] As a preferred embodiment of the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform described in this invention, the current transformer metering performance online monitoring device is connected to a current transformer calibrator, a data storage module, and a signaling alarm module. The current transformer metering performance online monitoring device is responsible for monitoring the performance of the current transformer and transmitting the monitoring data to the current transformer calibrator for verification, determining whether the performance of the current transformer meets the preset standard, and transmitting the monitoring data to the data storage module for storage. If an abnormality in the performance of the current transformer is detected, the current transformer metering performance online monitoring device will send an alarm signal to the signaling alarm module, which will then notify relevant personnel for handling. The online monitoring device for the metering performance of the current transformer includes a data preprocessing module, an error calculation module, and a KCL loop establishment module. The data preprocessing module preprocesses the collected current transformer performance data, including data cleaning and data conversion. The error calculation module calculates the error of the current transformer based on the preprocessed data, including the rated current ratio, phase difference, and ratio difference, and evaluates the performance of the current transformer. The KCL loop establishment module establishes the KCL loop based on the results of the error calculation module and monitors the performance of the current transformer. Construct the KCL matrix equation based on the KCL loop. The algebraic sum of the currents flowing out of any node is equal to zero. Calculate the sum of the real parts of all the inflow nodes of the substation and subtract the real parts of all the outflow nodes of the substation. Then calculate the sum of the imaginary parts of all the inflow nodes of the substation and subtract the imaginary parts of all the outflow nodes of the substation. Determine whether the error of the current transformer is zero. If the error of the current transformer cannot satisfy the KCL vector sum to be zero, an approximation method is used to adjust the error of several current transformers. The approximation method first adjusts the error value of a single current transformer, including the ratio difference and phase difference, in the order from the 1st to the nth transformer. If an error occurs during the adjustment that satisfies the condition that the KCL vector sum is zero, the error value of each current transformer after adjustment is recorded, and the adjusted error is the operating error of each current transformer. If the KCL vector sum cannot be equal to zero after the adjustment cycle, the number of current transformers involved in the adjustment is increased, and the error values ​​of two current transformers are adjusted simultaneously, using a round-robin method, starting with the first and second transformers, and if the condition is not met, adjusting the first and third transformers, and so on, until the KCL vector sum of the first, nth, or nth and n+1th transformers is zero. If adjusting two current transformers cannot make the KCL vector sum zero, the number of current transformers involved in the error adjustment continues to increase, from the nth transformer, the n+1th transformer, the n+2th transformer until the KCL vector sum is zero, and the error of all adjusted current transformers is recorded, which is the operating error value of each current transformer.

[0021] Another objective of this invention is to provide a multi-dimensional parameter adjustable current transformer error characteristic evaluation method. The relative deviation test method improves the ability to capture gradual signals, solves the defect of current transformer error evaluation based on signal processing modeling that cannot detect gradual error changes, and realizes the transformation from qualitative metrological status evaluation to quantitative error data analysis.

[0022] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a multi-dimensional parameter adjustable current transformer error characteristic evaluation method, comprising: back-calculating the true primary signal of the current transformer according to the current transformer error calculation formula of the current transformer calibrator, establishing a KCL loop composed of the monitored current transformers, constructing a matrix equation of the primary signal of the group of current transformers, adjusting the error value of each current transformer using an approximation method, and outputting the error of each operating current transformer.

[0023] As a preferred embodiment of the multi-dimensional parameter adjustable current transformer error characteristic evaluation method of the present invention, wherein: the switch is adjusted according to the user's needs to complete the configuration of the number of incoming and outgoing current transformers, and the input and output signals of the incoming and outgoing current transformers are connected to the transformer calibrator and the online monitoring device for current transformer metering performance. Among them, the current transformer calibrator needs to be connected to the input and output signals of the current transformer, while the online monitoring device for the metering performance of the current transformer only needs to be connected to the output signal of the current transformer. For the current transformer calibrator, the input signal of the current transformer is connected to its standard signal terminal, and the output signal is connected to its receiving signal terminal. The power supply unit is started, and the error and temperature chamber parameters of the incoming and outgoing current transformers are adjusted through the control display unit. After all parameters are adjusted, the transformer calibrator receives the error value of each incoming and outgoing current transformer after the test begins. This value is used as the standard value. At the same time, the online monitoring device for current transformer metering performance receives the output signals of the incoming and outgoing current transformers. The online monitoring device for current transformer metering performance calculates the error of each incoming and outgoing current transformer. Finally, the error value displayed by the transformer calibrator is compared with the error value calculated by the online monitoring device for current transformer metering performance. The difference between the two is the accuracy of the model of the online monitoring device for current transformer metering performance.

[0024] As a preferred embodiment of the multidimensional parameter-adjustable current transformer error characteristic evaluation method described in this invention, the method for inversely estimating the true primary signal of the current transformer is based on the current transformer error calculation formula, establishing an equation between the primary current and the secondary current, expressed as: ; in, This represents the effective value of the amplitude of the standard current signal. The effective value of the amplitude of the detected current signal. The initial phase angle of the standard current signal. The initial phase angle of the detected current signal is denoted as . The primary current of the first current transformer. This refers to the secondary current of the first current transformer. Rated current ratio The ratio difference of the first current transformer. The phase difference of the first current transformer; The KCL loop establishment module constructs the KCL matrix equation based on the KCL loop. The algebraic sum of the current flowing out of any node is equal to zero. It calculates the sum of the real parts of all the inflow nodes of the substation and subtracts the real parts of all the outflow nodes of the substation. Then it calculates the sum of the imaginary parts of all the inflow nodes of the substation and subtracts the imaginary parts of all the outflow nodes of the substation. Finally, it determines whether the error of the current transformer is zero. If the error of the current transformer cannot satisfy the KCL vector sum to be zero, an approximation method is used to adjust the error of several current transformers. Calculate the real and imaginary parts of a current transformer; The expression for calculating the real part of the current transformer is:

[0025] in, Let be the real part of the current transformer. The difference in ratios, This is the effective value of the amplitude. Rated current ratio;

[0026] in, This represents the imaginary part of the current transformer. This is the effective value of the phase. The initial phase difference, The unit is minutes. Divide by 60 to get degrees, then divide by 180. Convert the degree to radians, perform trigonometric function calculations, and multiply the effective value of the amplitude and the ratio of the rated current to output the imaginary part of the current transformer.

[0027] The beneficial effects of this invention are as follows: The design method of the multi-dimensional parameter adjustable current transformer error characteristic evaluation test platform proposed in this invention greatly improves the diversity, accuracy and reliability of current transformer error characteristic evaluation tests. It can realize the accuracy test of error characteristic evaluation of online monitoring device for current transformer metering performance, and can also be used in the development process of current transformer operation error evaluation model, providing a large amount of data for model training. It has extremely high scientific research value and testing value. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 The structural diagram of the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform provided in the first embodiment of the present invention; Figure 2 The flowchart of the test platform for evaluating the error characteristics of a multi-dimensional parameter adjustable current transformer provided in the second embodiment of the present invention; Figure 3 The internal design structure diagram of the error-adjustable current transformer group of the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform provided in the second embodiment of the present invention. Figure 4 Wiring diagram of the current transformer calibrator for the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform provided in the second embodiment of the present invention; Figure 5 The test platform signal transmission diagram is shown for the multi-dimensional parameter adjustable current transformer error characteristic evaluation platform provided in the second embodiment of the present invention. Detailed Implementation

[0029] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0030] Example 1 Reference Figure 1 As an embodiment of the present invention, a multi-dimensional parameter-adjustable current transformer error characteristic evaluation platform is provided, characterized in that: The system includes a power supply unit 100, a control and display unit 200, a standard value testing unit 300, an environmental control unit 400, an error-adjustable current transformer group 500, a transformer calibrator 600, an online monitoring device for current transformer metering performance 700, and a user interface 800. The power supply unit 100 provides power to the entire system and is connected to all modules that require power. The control display unit 200 is responsible for integrating the system's operating status and results, and displaying detailed operating data and analysis results to the user through a high-definition display screen; The standard value testing unit 300 is responsible for providing standard values, including the standard error value and standard current value of the current transformer; The environmental control unit 400 is responsible for monitoring and adjusting the system's operating environment, including temperature, humidity, and electromagnetic interference, so that the system operates under optimal environmental conditions. The error-adjustable current transformer group 500 adjusts the error of the current transformer; The current transformer calibrator 600 is responsible for calibrating the performance of the current transformer. Through precise testing instruments, it accurately measures the error and current value of the current transformer and sends the test results to the current transformer metering performance online monitoring device 700 for further analysis. The online monitoring device 700 for the metering performance of the current transformer is responsible for monitoring the performance of the current transformer. It collects real-time data of the metering winding of the current transformer at high frequency and performs a comprehensive analysis of the performance of the current transformer. The user interface 800 is responsible for interacting with the user and receiving user input. Through input devices such as touch screens or buttons, users can set system operating parameters, query operating data and analyze results. At the same time, the system's operating status and results will also be displayed to the user on the screen.

[0031] The control display unit 200 is connected to the user interface 800, the power supply unit 100, and the environmental control unit 400. The control display unit 200 receives input signals from the user interface 800 to realize human-computer interaction functions, obtains stable power from the power supply unit 100 to determine its normal operation, and adjusts the brightness, contrast, etc. of the display screen according to the environmental parameters provided by the environmental control unit 400 to ensure clear display under different environmental conditions. The control and display unit 200 includes a data display submodule 201, a human-computer interaction submodule 202, and a data processing submodule 203; The data display submodule 201 is responsible for displaying the system's operating data and analysis results on a high-definition display screen in the form of charts, text, etc., so that users can intuitively understand the system's operating status and results. The human-computer interaction submodule 202 is responsible for receiving input signals from the user interface 800 to realize human-computer interaction functions. Users can interact with the system through input devices such as touch screens and buttons, set system operating parameters, query operating data and analysis results; The data processing submodule 203 is responsible for processing user input, transmitting user operation instructions to the corresponding modules, realizing the system's control functions, and processing the system's operating data and analysis results, converting them into a form that the user can understand.

[0032] The standard value test unit 300 is connected to the parameter input module 801 and the power supply unit 100. It receives the basic parameters provided by the sub-module parameter input module 801 of the user interface 800, calculates the standard performance value of the current transformer, compares it with the actual measured value, evaluates the performance of the current transformer, and obtains the error of the current transformer. The basic parameters include the rated current and rated voltage of the current transformer and the amplitude of the current signal. The parameter input module 801 converts the input data into the format required by the system and transmits it to the standard value test unit 300 for processing. The standard value testing unit 300 includes a parameter receiving module 301, a data processing module 302, and a performance evaluation module 303. The parameter receiving module 301 receives the basic parameters provided by the parameter input module 801; The data processing module 302 converts the received basic parameters into the format required by the system and establishes an equation between the primary current and the secondary current, the expression of which is:

[0033] in, This represents the effective value of the amplitude of the standard current signal. The effective value of the amplitude of the detected current signal. The initial phase angle of the standard current signal. The initial phase angle of the detected current signal is denoted as . The primary current of the first current transformer. This refers to the secondary current of the first current transformer. Rated current ratio The ratio difference of the first current transformer. The phase difference of the first current transformer; The performance evaluation module 303 compares the calculated standard value with the actual measured value to evaluate the performance of the current transformer.

[0034] The environmental control unit 400 is connected to the power supply unit 100, the current transformer calibrator 600, and the current transformer metering performance online monitoring device 700 through sensors and controllers. The sensors of the environmental control unit 400 are responsible for monitoring the environmental conditions of the system operation, including temperature and humidity, and transmitting the monitored environmental data to the controller for processing. The controller analyzes the environmental data according to preset standard values ​​and determines whether the environmental conditions need to be adjusted. The environmental control unit 400 also includes a temperature control module 401 and a humidity control module 402. If the environmental conditions do not meet the preset standard values, the controller will send a control signal to the power supply unit 100 to start the corresponding adjustment device and adjust the environmental conditions to a suitable range. If the adjusted environmental parameters still do not meet the preset standard values, the environmental control unit 400 will send an abnormal signal to the control display unit 200, which will then issue a warning to the user interface 800 to notify the user to take further measures.

[0035] The adjustable current transformer group 500 is connected to the transformer calibrator 600. The adjustable current transformer group 500 receives the current transformer performance data transmitted from the transformer calibrator 600, adjusts the error of the current transformer according to the data, and then transmits the adjusted error data to the transformer calibrator 600. The transformer calibrator 600 recalibrates the performance of the current transformer according to the adjusted error data and determines whether the performance of the current transformer meets the preset standard. The performance verification of the current transformer includes verification of the rated current ratio, phase difference, phase difference, and environmental factors. If the rated current ratio, phase difference, or ratio difference does not meet the set threshold, the current transformer calibrator 600 sends an adjustment command and the actual rated current ratio, phase difference, or ratio difference to the error adjustable current transformer group 500, and the error adjustable current transformer group 500 adjusts the rated current ratio, phase difference, or ratio difference between the primary current and secondary current of the current transformer. If environmental factors do not meet the requirements, the current transformer calibrator 600 sends an adjustment command to the environmental control unit 400, which then adjusts the environmental conditions for system operation to determine whether the current transformer maintains stable performance under different environmental conditions such as temperature and humidity.

[0036] The current transformer calibrator 600 is connected to the online monitoring device for current transformer metering performance 700. The current transformer calibrator 600 receives real-time performance data of the current transformer transmitted by the online monitoring device for current transformer metering performance 700. Based on the received data, the current transformer calibrator 600 verifies the performance of the current transformer and determines whether its performance meets the preset standard. If the verification result shows that the performance of the current transformer does not meet the standard, the current transformer calibrator 600 will transmit this information to the error adjustable current transformer group 500, which will then adjust the error. The error-adjustable current transformer group 500 includes multiple current transformers, each with an adjustment device that can adjust the ratio between the primary current and the secondary current of the current transformer, thereby further adjusting the error of the current transformer.

[0037] The online monitoring device 700 for current transformer metering performance is connected to the current transformer calibrator 600, the data storage module, and the alarm transmission module. The online monitoring device 700 is responsible for monitoring the performance of the current transformer and transmitting the monitoring data to the current transformer calibrator 600 for verification to determine whether the performance of the current transformer meets the preset standards. The monitoring data is also transmitted to the data storage module for storage. If an abnormality in the performance of the current transformer is detected, the online monitoring device 700 will send an alarm signal to the alarm transmission module, which will then notify relevant personnel to handle the situation. The online monitoring device for metering performance of current transformers 700 includes a data preprocessing module 701, an error calculation module 702, and a KCL loop establishment module 703. The data preprocessing module 701 preprocesses the collected current transformer performance data, including data cleaning and data conversion. The error calculation module 702 calculates the error of the current transformer based on the preprocessed data, including the rated current ratio, phase difference, and ratio difference, and evaluates the performance of the current transformer. The KCL loop establishment module 703 establishes the KCL loop based on the result of the error calculation module 702 and monitors the performance of the current transformer. Construct the KCL matrix equation based on the KCL loop. The algebraic sum of the currents flowing out of any node is equal to zero. Calculate the sum of the real parts of all the inflow nodes of the substation and subtract the real parts of all the outflow nodes of the substation. Then calculate the sum of the imaginary parts of all the inflow nodes of the substation and subtract the imaginary parts of all the outflow nodes of the substation. Determine whether the error of the current transformer is zero. If the error of the current transformer cannot satisfy the KCL vector sum to be zero, an approximation method is used to adjust the error of several current transformers. The approximation method first adjusts the error value of a single current transformer, including the ratio difference and phase difference, in the order from the 1st to the nth transformer. If an error occurs during the adjustment that satisfies the condition that the KCL vector sum is zero, the error value of each current transformer after adjustment is recorded, and the adjusted error is the operating error of each current transformer. If the KCL vector sum cannot be equal to zero after the adjustment cycle, the number of current transformers involved in the adjustment is increased, and the error values ​​of two current transformers are adjusted simultaneously, using a round-robin method, starting with the first and second transformers, and if the condition is not met, adjusting the first and third transformers, and so on, until the KCL vector sum of the first, nth, or nth and n+1th transformers is zero. If adjusting two current transformers cannot make the KCL vector sum zero, the number of current transformers involved in the error adjustment continues to increase, from the nth transformer, the n+1th transformer, the n+2th transformer until the KCL vector sum is zero, and the error of all adjusted current transformers is recorded, which is the operating error value of each current transformer.

[0038] Based on the error calculation formula of the current transformer calibrator 600, the true primary signal of the current transformer is deduced, the KCL loop composed of the monitored current transformers is established, the matrix equation of the primary signal of the group of current transformers is constructed, and the error value of each current transformer is adjusted by an approximation method, and the error of each operating current transformer is output.

[0039] Adjust the switch according to user needs to complete the configuration of the number of incoming and outgoing current transformers, and connect the input and output signals of the incoming and outgoing current transformers to the transformer calibrator 600 and the online monitoring device for current transformer metering performance 700. Among them, the current transformer calibrator 600 needs to be connected to the input and output signals of the current transformer, while the current transformer metering performance online monitoring device 700 only needs to be connected to the output signal of the current transformer. For the current transformer calibrator, the input signal of the current transformer is connected to its standard signal terminal, and the output signal is connected to its receiving signal terminal. The power supply unit 100 is started, and the error and temperature chamber parameters of the incoming and outgoing current transformers are adjusted through the control display unit 200. After all parameters are adjusted, the transformer calibrator 600 receives the error value of each incoming and outgoing current transformer after the test begins. This value is used as the standard value. At the same time, the online monitoring device for current transformer metering performance receives the output signals of the incoming and outgoing current transformers. The online monitoring device for current transformer metering performance calculates the error of each incoming and outgoing current transformer within the online monitoring device for current transformer metering performance. Finally, the error value displayed by the transformer calibrator 600 is compared with the error value calculated by the online monitoring device for current transformer metering performance. The difference between the two is the accuracy of the model of the online monitoring device for current transformer metering performance.

[0040] The method for calculating the true primary signal of the current transformer is based on the current transformer error calculation formula, establishing an equation between the primary and secondary currents, expressed as follows:

[0041] in, This represents the effective value of the amplitude of the standard current signal. The effective value of the amplitude of the detected current signal. The initial phase angle of the standard current signal. The initial phase angle of the detected current signal is denoted as . The primary current of the first current transformer. This refers to the secondary current of the first current transformer. Rated current ratio The ratio difference of the first current transformer. The phase difference of the first current transformer; The KCL loop establishment module 703 current transformer constructs the KCL matrix equation based on the KCL loop. The algebraic sum of the current flowing out of any node is equal to zero. It calculates the sum of the real parts of all inflow nodes in the substation and subtracts the real parts of all outflow nodes in the substation. Then it calculates the sum of the imaginary parts of all inflow nodes in the substation and subtracts the imaginary parts of all outflow nodes in the substation to determine whether the error of the current transformer is zero. If the error of the current transformer cannot satisfy the KCL vector sum to be zero, an approximation method is used to adjust the error of several current transformers. Calculate the real and imaginary parts of a current transformer; The expression for calculating the real part of the current transformer is:

[0042] in, Let be the real part of the current transformer. The difference in ratios, This is the effective value of the amplitude. Rated current ratio;

[0043] in, This represents the imaginary part of the current transformer. This is the effective value of the phase. The initial phase difference, The unit is minutes. Divide by 60 to get degrees, then divide by 180. Convert the degree to radians, perform trigonometric function calculations, and multiply the effective value of the amplitude and the ratio of the rated current to output the imaginary part of the current transformer.

[0044] Example 2 Reference Figures 2-5 In this embodiment, to verify the beneficial effects of the present invention, scientific demonstration is conducted through economic benefit calculations and simulation experiments. This embodiment presents experiments comparing both existing conventional methods and the method of this embodiment.

[0045] The operating process of this patent is as follows: Figure 2 As shown. First, adjust the switches according to user needs to configure the number of incoming and outgoing CTs; then, connect the input and output signals of the incoming and outgoing CTs to the current transformer calibrator and the online monitoring device for current transformer metering performance. The current transformer calibrator needs to be connected to both the input and output signals of the CTs, while the online monitoring device for current transformer metering performance only needs to be connected to the output signal of the CTs. For the current transformer calibrator, the CT input signal is connected to its standard signal terminal, and the output signal is connected to its receiving signal terminal. Then, the power is turned on, and the error of the incoming and outgoing CTs and the temperature chamber parameters are adjusted through the control display unit. After all parameters are adjusted, the test is officially started. After the test begins, the current transformer calibrator will receive the error value of each incoming and outgoing CT, using this value as the standard value. At the same time, the current transformer metering performance online monitoring device receives the output signals of the incoming and outgoing CTs, and completes the error calculation of each incoming and outgoing CT within the current transformer metering performance online monitoring device. Finally, the error value displayed by the current transformer calibrator and the error value calculated by the current transformer metering performance online monitoring device are compared. The difference between the two is the accuracy of the current transformer metering performance online monitoring device model.

[0046] The internal design structure of the error-adjustable current transformer group is as follows: Figure 2As shown. Current transformers are represented by the symbol CT. CTs are distributed in four locations: incoming CTs, bus tie CTs, transformer-side CTs, and outgoing CTs. The error of each CT can be adjusted independently. There can be multiple incoming lines; this test platform is designed with two incoming lines, but more can be added. Incoming current transformers are represented by CT1, CT2, CTa, CT4, CT5, and CTb, where CTa and CTb represent multiple sets of current transformers, meaning the incoming CTs can be adjusted according to user needs. Similarly, the number of outgoing lines and the number of CTs on each outgoing line can be adjusted according to user needs. This patent uses CT10 to CT18 to represent outgoing CTs, where CTc and CTd represent multiple sets of current transformers, which can be selected and switched according to user needs.

[0047] Figure 3 In this setup, each CT group contains three phases: A, B, and C. K1 represents the switch on bus tie 1, T1 and T2 represent transformers, K2 and K3 represent transformer-side switches, and K4 represents the switch on bus tie 2. The number of operating current transformers on the incoming and outgoing lines is adjusted by switching K1, K2, K3, and K4. RLC represents an internally programmable analog load; the programmable source provides an adjustable voltage source, which, in conjunction with the RLC module, controls the current within the test platform.

[0048] The error test wiring principle of this patent is as follows: Figure 4 As shown in the diagram, each group of CTs represents a 3-phase current transformer, namely A, B, and C. This patent design uses a 1:1 transformation ratio for each CT, making the input current of each CT a standard signal. Both the input and output signals of each CT are connected to a current transformer calibrator, which serves as the standard value testing unit for each CT. The input signal of each CT is used as the standard current signal, and the output signal is used as the measured current signal. The current transformer calibrator detects the error of each current transformer using the difference method. This design achieves standard signal extraction even without an independent standard current transformer within the platform.

[0049] The signal transmission path of this patent is as follows: Figure 5 As shown, all current transformers are placed in a temperature chamber, which allows for adjustment of the ambient temperature and humidity for all operating current transformers. The transformer calibrator, programmable logic controller (PLC), and control display unit are all located in a laboratory environment. The PLC provides power to the current transformers. The input signal from each current transformer enters the transformer calibrator, and the output signal exits from the temperature chamber and enters the calibrator. The control display unit controls the PLC parameters, and the test results from the transformer calibrator are transmitted to the control display unit. The control display unit can control the error of each current transformer (CT) and also control the temperature chamber parameters.

[0050] A manufacturer's online monitoring device for the metering performance of current transformers needs to undergo error characteristic evaluation testing to verify the accuracy of its algorithm for calculating and evaluating the errors of operating current transformers. This patent is used to conduct the test, and data analysis is carried out using data from phase A current transformer as an example. The steps are as follows: 1) Select a voltage transformer operating topology, such as a single-input, multi-output operating mode. Open switches K1 and K3, close switches K2 and K4. CT1 and CT2 form the incoming current transformer group, and CT10, CT11, CT12, CT13, CT15, CT16, CT17, and CT18 form the outgoing current transformer group. The company's online monitoring device for current transformer metering performance consists of 13 groups with 36 current signal acquisition channels. Connect the online monitoring device for current transformer metering performance in series with CT1, CT2, CT6, CT7, CT10, CT11, CT12, CT13, CT15, CT16, CT17, and CT18. After completing the connection of all 36 channels, all wiring is finished.

[0051] 2) Adjust the RLC parameters to complete the adjustment of one power supply parameter. Adjust the temperature chamber parameters, assuming the temperature chamber environment is +25℃ and the relative humidity is 66%.

[0052] 3) Start the platform's programmable source and run the platform with power on. Adjust the ratio difference and phase difference of CT1, CT2, CT6, CT7, CT10, CT11, CT12, CT13, CT15, CT16, CT17, and CT18. After adjustment, connect the input and output signals of CT1, CT2, CT6, CT7, CT10, CT11, CT12, CT13, CT15, CT16, CT17, and CT18 to the current transformer calibrator. The current transformer calibrator uses the difference method to calculate the actual error of CT1, CT2, CT6, CT7, CT10, CT11, CT12, CT13, CT15, CT16, CT17, and CT18 after adjustment. This error is used as the standard signal. Assume the current transformer calibrator detects the following errors for CT1, CT2, CT6, CT7, CT10, CT11, CT12, CT13, CT15, CT16, CT17, and CT18: +0.04%, 1.5´; +0.12%, 0.5´; +0.38%, 16.0´; +0.06%, 2.2´; +0.11%, 0.1´; +0.08%, 0.5´; +0.08%, 3.0´; +0.25%, 2.5´; +0.07%, 0.3´; +0.02%, 5.2´; +0.11%, 3.0´; +0.11%, 1.2´; +0.34%, 1.2´.

[0053] 4) After the online monitoring device for the metering performance of current transformers has been running for a period of time, it calculates the ratio difference and phase difference of CT1, CT2, CT6, CT7, CT10, CT11, CT12, CT13, CT15, CT16, CT17, and CT18. Assuming the online monitoring device for the metering performance of current transformers calculates the ratio difference and phase difference of CT1, CT2, CT6, CT7, CT10, CT11, CT12, CT13, CT15, CT16, and CT17, ... The CT18 errors are as follows: +0.13%, 3.4´; +0.18%, 2.1´; +0.45%, 18.3´; +0.01%, 4.2´; +0.07%, 3.0´; +0.03%, 1.9´; +0.08%, 4.2´; +0.33%, 4.4´; +0.01%, 3.1´; -0.04%, 7.2´; 0.17%, 3.5´; +0.19%, 3.3´; +0.38%, 4.1´.

[0054] 5) Compare the calculation results of the online monitoring device for the metering performance of current transformers with the standard signal detected by the transformer calibrator. Subtract the calculation results from the standard signal to obtain the deviations of the errors of CT1, CT2, CT6, CT7, CT10, CT11, CT12, CT13, CT15, CT16, CT17, and CT18 calculated by the online monitoring device: -0.09%, -1.9´; -0.06%, -1.6´; -0.07%, -2.3´; +0.05%, -2.0´; +0.04%, -2.9´; +0.05%, -1.4´; -0.06%, -1.2´; -0.08%-1.9´; +0.06%, -2.8´; +0.06%, -2.0´; -0.06%, -0.5.0´; -0.08%, -2.1´; -0.04%, -2.9´. Among the 13 groups of current transformers, the largest deviations in the calculation results are -0.09% and -2.9'. Therefore, the accuracy of the online monitoring device for the metering performance of current transformers produced by the company in assessing the error characteristics of current transformers is ±0.1% and ±3.0'.

[0055] All transformers and current transformers within this test platform have a 1:1 turns ratio, which makes the input current the standard current signal for the current transformers. This allows the entire test platform to provide a standard current signal even without installing standard current transformers, reducing the equipment requirements by half. Furthermore, using the input current as the standard current signal ensures that it is an error-free standard signal. Therefore, the error of each current transformer obtained by the transformer calibrator by comparing the standard current transformer with the output signal of the current transformer is accurate and reliable.

[0056] This invention places all current transformers with adjustable errors in a temperature chamber to simulate the impact of seasonal temperature changes on the errors of current transformers. This enhances the versatility of the test platform and allows for the examination of the slow changes in errors of current transformers with temperature variations during long-term operation. It also provides long-term live-line testing capability when verifying the online monitoring algorithm model for the metering performance of current transformers.

[0057] This invention enables various operating modes for incoming and outgoing current transformers by switching switches, meeting the different operating requirements of various incoming and outgoing current transformers and significantly improving the diversity of operating modes of current transformers in simulated power plants.

[0058] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A multi-dimensional parameter-adjustable current transformer error characteristic evaluation platform, characterized in that, include: The system includes a power supply unit (100), a control and display unit (200), a standard value testing unit (300), an environmental control unit (400), an error-adjustable current transformer group (500), a transformer calibrator (600), an online monitoring device for current transformer metering performance (700), and a user interface (800). The power supply unit (100) provides power to the entire system and is connected to all modules that require power. The control display unit (200) is responsible for integrating the system's operating status and results, and displaying detailed operating data and analysis results to the user through a high-definition display screen; The standard value test unit (300) is responsible for providing standard values, including the standard error value and standard current value of the current transformer; The environmental control unit (400) is responsible for monitoring and adjusting the system's operating environment, including temperature, humidity, and electromagnetic interference, so that the system operates under optimal environmental conditions. The error-adjustable current transformer group (500) adjusts the error of the current transformer; The current transformer calibrator (600) is responsible for calibrating the performance of the current transformer. Through precise testing instruments, it accurately measures the error and current value of the current transformer and sends the test results to the online monitoring device for current transformer metering performance (700) for further analysis. The online monitoring device (700) for metering performance of current transformers is responsible for monitoring the performance of current transformers. It collects real-time data of the metering windings of the operating current transformers at high frequency and performs a comprehensive analysis of the performance of the current transformers. The user interface (800) is responsible for interacting with the user, receiving the user's input, and inputting the device through the touch screen or buttons. The user sets the system's operating parameters, queries operating data and analyzes results. At the same time, the system's operating status and results are also displayed to the user through the screen. The online monitoring device for metering performance of the current transformer (700) includes a data preprocessing module (701), an error calculation module (702), and a KCL loop establishment module (703). The error calculation module (702) calculates the error of the current transformer based on the preprocessed data, including the rated current ratio, phase difference, and ratio difference, and evaluates the performance of the current transformer. The KCL loop establishment module (703) establishes the KCL loop based on the result of the error calculation module (702) and monitors the performance of the current transformer. Construct the KCL matrix equation based on the KCL loop. The algebraic sum of the currents flowing out of any node is equal to zero. Calculate the sum of the real parts of all the inflow nodes of the substation and subtract the real parts of all the outflow nodes of the substation. Then calculate the sum of the imaginary parts of all the inflow nodes of the substation and subtract the imaginary parts of all the outflow nodes of the substation. Determine whether the error of the current transformer is zero. If the error of the current transformer cannot satisfy the KCL vector sum to be zero, an approximation method is used to adjust the error of several current transformers. The approximation method first adjusts the error value of a single current transformer, including the ratio difference and phase difference, in the order from the 1st to the nth transformer. If an error occurs during the adjustment that satisfies the condition that the KCL vector sum is zero, the error value of each current transformer after adjustment is recorded, and the adjusted error is the operating error of each current transformer. If the KCL vector sum cannot be equal to zero after the adjustment cycle, the number of current transformers involved in the adjustment is increased, and the error values ​​of two current transformers are adjusted simultaneously, using a round-robin method, starting with the first and second transformers, and if the condition is not met, adjusting the first and third transformers, and so on, until the KCL vector sum of the first, nth, or nth and n+1th transformers is zero. If adjusting two current transformers cannot make the KCL vector sum zero, the number of current transformers involved in the error adjustment continues to increase, from the nth transformer, the n+1th transformer, the n+2th transformer until the KCL vector sum is zero, and the error of all adjusted current transformers is recorded, which is the operating error value of each current transformer.

2. The multi-dimensional parameter adjustable current transformer error characteristic evaluation platform as described in claim 1, characterized in that: The control display unit (200) is connected to the user interface (800), the power supply unit (100), and the environmental control unit (400). The control display unit (200) receives input signals from the user interface (800) to realize human-computer interaction. It obtains a stable power supply through the power supply unit (100) to determine its normal operation. Based on the environmental parameters provided by the environmental control unit (400), it adjusts the brightness and contrast of the display screen to ensure clear display under different environmental conditions. The control and display unit (200) includes a data display submodule (201), a human-computer interaction submodule (202), and a data processing submodule (203). The data display submodule (201) is responsible for displaying the system's operating data and analysis results in the form of charts and text on the high-definition display screen, so that users can intuitively understand the system's operating status and results; The human-computer interaction submodule (202) is responsible for receiving input signals from the user interface (800) to realize human-computer interaction functions. Users can interact with the system through touch screen and button input devices, set system operating parameters, query operating data and analysis results; The data processing submodule (203) is responsible for processing user input, transmitting user operation instructions to the corresponding modules, realizing the system's control functions, and processing the system's operating data and analysis results, converting them into a form that the user can understand.

3. The multi-dimensional parameter adjustable current transformer error characteristic evaluation platform as described in claim 2, characterized in that: The standard value test unit (300) is connected to the parameter input module (801) and the power supply unit (100), receives the basic parameters provided by the sub-module parameter input module (801) of the user interface (800), calculates the standard performance value of the current transformer, compares it with the actual measured value, evaluates the performance of the current transformer, and obtains the error of the current transformer. The basic parameters include the rated current, rated voltage and amplitude of the current transformer. The parameter input module (801) converts the input data into the format required by the system and passes it to the standard value test unit (300) for processing. The standard value test unit (300) includes a parameter receiving module (301), a data processing module (302), and a performance evaluation module (303). The parameter receiving module (301) receives the basic parameters provided by the parameter input module (801); The data processing module (302) converts the received basic parameters into the format required by the system and establishes an equation between the primary current and the secondary current, the expression of which is: ； in, This represents the effective value of the amplitude of the standard current signal. The effective value of the amplitude of the detected current signal. The initial phase angle of the standard current signal. The initial phase angle of the detected current signal is denoted as . The primary current of the first current transformer. This refers to the secondary current of the first current transformer. Rated current ratio The ratio difference of the first current transformer. The phase difference of the first current transformer; The performance evaluation module (303) compares the calculated standard value with the actual measured value to evaluate the performance of the current transformer.

4. The multi-dimensional parameter adjustable current transformer error characteristic evaluation platform as described in claim 3, characterized in that: The environmental control unit (400) is connected to the power supply unit (100), the transformer calibrator (600), and the online monitoring device for current transformer metering performance (700) through sensors and controllers. The sensors of the environmental control unit (400) are responsible for monitoring the environmental conditions of the system operation, including temperature and humidity, and transmitting the monitored environmental data to the controller for processing. The controller analyzes the environmental data according to the preset standard values ​​and determines whether the environmental conditions need to be adjusted. The environmental control unit (400) also includes a temperature control module (401) and a humidity control module (402). If the environmental conditions do not meet the preset standard values, the controller will send a control signal to the power supply unit (100) to start the corresponding adjustment device and adjust the environmental conditions to a suitable range. If the adjusted environmental parameters still do not meet the preset standard values, the environmental control unit (400) will send an abnormal signal to the control display unit (200), and the control display unit (200) will issue a warning to the user interface (800) to notify the user to take further measures.

5. The multi-dimensional parameter adjustable current transformer error characteristic evaluation platform as described in claim 4, characterized in that: The adjustable current transformer group (500) is connected to the transformer calibrator (600). The adjustable current transformer group (500) receives the current transformer performance data transmitted from the transformer calibrator (600), adjusts the error of the current transformer according to the data, and then transmits the adjusted error data to the transformer calibrator (600). The transformer calibrator (600) re-calibrates the performance of the current transformer according to the adjusted error data and determines whether the performance of the current transformer meets the preset standard. The performance verification of the current transformer includes verification of the rated current ratio, phase difference, phase difference, and environmental factors. If the rated current ratio or phase difference or ratio difference does not meet the set threshold, the current transformer calibrator (600) sends an adjustment command and the actual rated current ratio or phase difference or ratio difference to the error adjustable current transformer group (500), and the error adjustable current transformer group (500) adjusts the rated current ratio, phase difference, and ratio difference between the primary current and secondary current of the current transformer. If environmental factors do not meet the requirements, the current transformer calibrator (600) sends an adjustment command to the environmental control unit (400), which adjusts the environmental conditions for system operation to determine whether the current transformer maintains stable performance under different temperature and humidity conditions.

6. The multi-dimensional parameter adjustable current transformer error characteristic evaluation platform as described in claim 5, characterized in that: The current transformer calibrator (600) is connected to the online monitoring device for current transformer metering performance (700). The current transformer calibrator (600) receives real-time performance data of the current transformer transmitted by the online monitoring device for current transformer metering performance (700). Based on the received data, the current transformer calibrator (600) verifies the performance of the current transformer and determines whether its performance meets the preset standard. If the verification result shows that the performance of the current transformer does not meet the standard, the current transformer calibrator (600) will transmit this information to the error adjustable current transformer group (500) for error adjustment. The error-adjustable current transformer group (500) includes multiple current transformers, each of which has an adjustment device to adjust the ratio between the primary current and the secondary current of the current transformer, thereby further adjusting the error of the current transformer.

7. The multi-dimensional parameter adjustable current transformer error characteristic evaluation platform as described in claim 6, characterized in that: The online monitoring device (700) for current transformer metering performance is connected to the current transformer calibrator (600), the data storage module, and the alarm transmission module. The online monitoring device (700) is responsible for monitoring the performance of the current transformer and transmitting the monitoring data to the current transformer calibrator (600) for verification to determine whether the performance of the current transformer meets the preset standard. The monitoring data is transmitted to the data storage module for storage. If an abnormality in the performance of the current transformer is detected, the online monitoring device (700) will send an alarm signal to the alarm transmission module, which will then notify relevant personnel to handle the situation. The data preprocessing module (701) preprocesses the collected current transformer performance data, including data cleaning and data conversion.

8. A method for evaluating the error characteristics of a current transformer using a multi-dimensional parameter-adjustable current transformer as described in any one of claims 1 to 7, characterized in that: Based on the current transformer error calculation formula of the current transformer calibrator (600), the true primary signal of the current transformer is deduced, the KCL loop composed of the monitored current transformers is established, the matrix equation of the primary signal of the group current transformers is constructed, the approximation method is used to adjust the error value of each current transformer, and the error of each operating current transformer is output.

9. The method for evaluating the error characteristics of a multi-dimensional parameter-adjustable current transformer as described in claim 8, characterized in that: Adjust the switch according to user needs to complete the configuration of the number of incoming and outgoing current transformers, and connect the input and output signals of the incoming and outgoing current transformers to the transformer calibrator (600) and the online monitoring device for current transformer metering performance (700). Among them, the current transformer calibrator (600) needs to be connected to the input signal and output signal of the current transformer, while the current transformer metering performance online monitoring device (700) only needs to be connected to the output signal of the current transformer. For the current transformer calibrator, the input signal of the current transformer is connected to its standard signal terminal, and the output signal is connected to its receiving signal terminal. Start the power supply unit (100), and adjust the error and temperature chamber parameters of the incoming and outgoing current transformers respectively through the control display unit (200). After all parameters are adjusted, the transformer calibrator (600) will receive the error value of each incoming and outgoing current transformer after the test starts. This value is used as the standard value. At the same time, the online monitoring device for current transformer metering performance (700) receives the output signal of the incoming and outgoing current transformers. The error calculation of each incoming and outgoing current transformer is completed inside the online monitoring device for current transformer metering performance (700). Finally, the error value displayed by the transformer calibrator (600) and the error value calculated by the online monitoring device for current transformer metering performance (700) are compared. The difference between the two is the accuracy of the model of the online monitoring device for current transformer metering performance.

10. The method for evaluating the error characteristics of a multi-dimensional parameter-adjustable current transformer as described in claim 8, characterized in that: The method for calculating the true primary signal of the current transformer is based on the current transformer error calculation formula, establishing an equation between the primary and secondary currents, expressed as follows: ； in, This represents the effective value of the amplitude of the standard current signal. The effective value of the amplitude of the detected current signal. The initial phase angle of the standard current signal. The initial phase angle of the detected current signal is denoted as . The primary current of the first current transformer. This refers to the secondary current of the first current transformer. Rated current ratio The ratio difference of the first current transformer. The phase difference of the first current transformer; The KCL loop establishment module (703) constructs the KCL matrix equation based on the KCL loop. The algebraic sum of the current flowing out of any node is equal to zero. It calculates the sum of the real parts of all the inflow nodes of the substation and subtracts the real parts of all the outflow nodes of the substation. Then it calculates the sum of the imaginary parts of all the inflow nodes of the substation and subtracts the imaginary parts of all the outflow nodes of the substation. It then determines whether the error of the current transformer is zero. If the error of the current transformer cannot satisfy the KCL vector sum to be zero, an approximation method is used to adjust the error of several current transformers. Calculate the real and imaginary parts of a current transformer; The expression for calculating the real part of the current transformer is: ； in, Let be the real part of the current transformer. The difference in ratios, This is the effective value of the amplitude. Rated current ratio; ； in, This represents the imaginary part of the current transformer. This is the effective value of the phase. The initial phase difference, The unit is minutes. Divide by 60 to convert minutes to degrees, then divide by 180π to convert degrees to radians. Perform trigonometric function calculations and multiply the effective value of the amplitude and the ratio of the rated current to output the imaginary part of the current transformer.

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