A high-voltage current transformer automatic verification device

Abstract

This invention relates to the field of electrical testing technology and discloses an automated calibration device for high-voltage current transformers. The device includes an integrated test base with an open support structure in the central area. A temperature control element and a force sensor array are embedded within the integrated test base. Adjustable mechanical clamps are arranged around the open support structure. The force sensor array is connected to an external data acquisition system. A thermomechanical coupling self-calibration system includes a zoned temperature control unit and a programmable mechanical load applicator. A data fusion analysis unit uses a thermomechanical coupling model for real-time data processing and analysis to construct performance curves of the high-voltage current transformer under specific temperature and mechanical load combinations. This invention achieves coordinated control of the temperature field and mechanical stress field, accurately simulating the thermomechanical coupling state of the high-voltage current transformer in the actual operating environment, and reducing the deviation between the calibration results and the actual operating state.

Description

Technical Field

[0001] This invention relates to the field of electrical testing technology, and more specifically, to an automated calibration device for high-voltage current transformers. Background Technology

[0002] High-voltage current transformers, as key devices for measuring large currents in power systems, simultaneously withstand the heat generated by the current and the mechanical stress generated during installation and fixing in actual operating environments. These two physical factors interact, forming a complex thermomechanical coupling effect.

[0003] Specifically, the heat generated when current passes through an instrument transformer causes thermal expansion of the material, which in turn alters the distribution of mechanical stress within the transformer. Simultaneously, the mechanical stress experienced by the transformer also affects the material's thermal conductivity and temperature distribution. This bidirectional coupling effect is often overlooked in traditional verification methods, leading to discrepancies between verification results and actual operating conditions. This results in an inaccurate reflection of the instrument transformer's performance characteristics in real-world operating environments, ultimately impacting the safe and stable operation of the power system. Summary of the Invention

[0004] This invention provides an automated calibration device for high-voltage current transformers, which solves the technical problem that the bidirectional coupling effect is often ignored in traditional calibration methods, leading to deviations between calibration results and actual operating conditions.

[0005] This invention provides an automated calibration device for high-voltage current transformers, comprising:

[0006] An integrated test base is used to support the high-voltage current transformer to be calibrated. An open support structure is provided in the central area of ​​the surface. Temperature control elements and a force sensor array are embedded inside the integrated test base. Adjustable mechanical clamps are arranged around the open support structure of the integrated test base to clamp the high-voltage current transformer. The force sensor array is connected to an external data acquisition system to monitor the stress state of the high-voltage current transformer in real time. A multi-point laser scanning measurement unit is fixedly connected to the integrated test base and connected to a data fusion analysis unit through a synchronous signal line to provide accurate spatial deformation information for thermomechanical coupling analysis.

[0007] The thermomechanical coupling self-calibration system includes a partitioned temperature control unit and a programmable mechanical load applicator, which is used to simultaneously apply a precise temperature field and mechanical stress field to a high-voltage current transformer;

[0008] The data fusion and analysis unit uses a thermomechanical coupling model for real-time data processing and analysis to construct the performance curves of high-voltage current transformers under specific temperature and mechanical load combinations.

[0009] The partition temperature control unit consists of multiple independently controlled heating zones arranged in a ring to form a regionally controllable temperature field around the high-voltage current transformer. Additional temperature sensors are set at the boundary of the heating zones to monitor the temperature gradient of adjacent zones in real time.

[0010] The programmable mechanical load applicator employs a multi-point servo motor driven pressure arm structure to apply controllable mechanical stress to the high-voltage current transformer. One end of the pressure arm is connected to the integrated test base via a pressure arm bracket, and the other end is equipped with a pressure contact head that matches the surface of the high-voltage current transformer.

[0011] Furthermore, the servo motor is fixedly connected to the pressure arm, and the servo motor drives the pressure arm to generate precise pressure through a precision lead screw mechanism. Multiple pressure arms are evenly distributed around the high-voltage current transformer, and the multiple pressure arms adopt a layered staggered arrangement design.

[0012] Furthermore, the open support structure of the integrated test base includes fixing holes on the integrated test base, which are fixed to the bottom of the high-voltage current transformer by screws. The integrated test base is firmly connected to the ground or workbench by anti-vibration fixing bolts at the bottom for the stability of the integrated test base.

[0013] Furthermore, the mechanical fixing fixture includes multiple radially telescopic clamping arms, each equipped with an elastic pressure pad that can be adjusted according to the dimensions of the high-voltage current transformer. By uniformly applying radial pressure, the high-voltage current transformer is firmly locked onto the open support structure. The clamping arms are connected to the integrated test base via precision slide rails, which accurately position and lock the high-voltage current transformer after installation.

[0014] Furthermore, the multi-point laser scanning measurement unit is arranged in a ring array around the high-voltage current transformer. The multi-point laser scanning measurement unit consists of multiple laser ranging sensors, each of which adopts a miniaturized design.

[0015] Furthermore, each heating zone of the partitioned temperature control unit includes a temperature sensing probe and a heating element, and a gradient heating control scheme is adopted between each heating zone to achieve a smooth temperature transition between adjacent heating zones through software algorithms.

[0016] Furthermore, the pressure arm is made of high-strength alloy material, and one end is connected to the integrated test base by a hinge to form a rotation fulcrum. The pressure arm is in a ring at different height levels, with adjacent pressure arms located at different height levels. The rotation fulcrum of each pressure arm is arranged in a concentric circle array around the integrated test base, and the fulcrums are distributed at equal angles.

[0017] Furthermore, the data fusion analysis unit includes a data acquisition interface, a data processing module, and a model calculation module, which are connected in sequence. The model calculation module analyzes the mechanical deformation caused by temperature changes and the temperature distribution changes caused by mechanical stress based on the thermomechanical coupling theory.

[0018] Furthermore, the servo motors of each pressure arm are controlled collaboratively by a central controller, and an anti-collision algorithm is used to calculate and adjust the movement path of each pressure arm in real time.

[0019] The method for the automated calibration device for high-voltage current transformers includes: acquiring reference data at ambient temperature; constructing a thermomechanical coupling environment through a zoned temperature control unit and a programmable mechanical load applicator; performing calibration tests in the thermomechanical coupling environment; monitoring surface deformation through a multi-point laser scanning measurement unit; and processing and correcting the data based on the thermomechanical coupling model by a data fusion analysis unit to generate a thermomechanical coupling characteristic curve.

[0020] This invention provides a method for calibrating a high-voltage current transformer using an automated calibration device, comprising: acquiring reference data at ambient temperature; constructing a thermomechanical coupling environment through a zoned temperature control unit and a programmable mechanical load applicator; performing calibration tests in the thermomechanical coupling environment; monitoring surface deformation through a multi-point laser scanning measurement unit; and processing and correcting the data based on a thermomechanical coupling model by a data fusion analysis unit to generate a thermomechanical coupling characteristic curve.

[0021] The beneficial effects of this invention are as follows:

[0022] First, the composite material structure and embedded sensor design of the integrated test base provide a stable and controllable support environment for the high-voltage current transformer, reducing the impact of installation errors on the calibration results. The real-time monitoring function of the force sensor array visualizes the stress state of the high-voltage current transformer during calibration, ensuring the accuracy and repeatability of mechanical stress application.

[0023] Secondly, the zoned temperature control unit and programmable mechanical load applicator in the thermomechanical coupling self-calibration system achieve coordinated control of the temperature field and mechanical stress field, accurately simulating the thermomechanical coupling state of the high-voltage current transformer in the actual operating environment. The annular heating zone and multi-point pressure arm structure ensure the uniformity and flexibility of the temperature and stress field distribution, avoiding nonlinear effects caused by local hot spots or stress concentration.

[0024] Third, the introduction of the multi-point laser scanning measurement unit solves the technical challenge of capturing minute deformations on the surface of high-voltage current transformers. The miniaturized design and precision optical focusing system enable the multi-point laser scanning measurement unit to achieve high-precision deformation monitoring without contacting the high-voltage current transformer, providing accurate calibration data for the thermomechanical coupling model and further improving the reliability of the verification results.

[0025] Fourth, the data fusion analysis unit employs a thermomechanical coupling model, integrating temperature changes, mechanical stress, and high-voltage current transformer performance parameters into a unified analytical framework. This reveals the influence mechanism of thermomechanical coupling effects on the metering characteristics of high-voltage current transformers. This data processing method based on a physical model is more scientific and accurate than traditional empirical corrections, and can effectively identify and compensate for measurement errors caused by thermomechanical coupling effects.

[0026] The automated calibration device for high-voltage current transformers of the present invention enables accurate calibration of high-voltage current transformers under complex thermomechanical coupling environments. The calibration results are closer to the actual working state of high-voltage current transformers, providing a more reliable basis for performance evaluation and fault diagnosis of high-voltage current transformers, and providing stronger technical support for the safe and stable operation of power systems. Attached Figure Description

[0027] Figure 1 This is an overall schematic diagram of the automated calibration device for high-voltage current transformers of the present invention;

[0028] Figure 2 This is a front view of the automated calibration device for high-voltage current transformers of the present invention;

[0029] Figure 3 This is a top view of the automated calibration device for high-voltage current transformers of the present invention;

[0030] Figure 4 This is an overall schematic diagram of the pressure arm of the present invention;

[0031] Figure 5 This is a side view of the pressure arm of the present invention;

[0032] Figure 6 This is a top view of the pressure arm of the present invention;

[0033] In the diagram: 100, integrated test base; 101, anti-vibration fixing bolt; 102, clamping arm; 103, precision slide rail; 104, multi-point laser scanning measurement unit; 200, thermomechanical coupling self-calibration system; 201, heating element; 202, pressure arm; 203, temperature sensing probe; 204, pressure contact head; 300, high-voltage current transformer. Detailed Implementation

[0034] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, some features described in the examples may be combined in other examples.

[0035] At least one embodiment of the present invention discloses an automated calibration device for high-voltage current transformers, such as... Figure 1 - Figure 6 As shown, it includes an integrated test base 100, a thermomechanical coupling self-calibration system 200, and a data fusion analysis unit.

[0036] An open support structure is provided in the central area of ​​the surface of the integrated test base 100. The open support structure includes fixing holes on the integrated test base 100 and is fixed to the bottom of the high voltage current transformer 300 by screws.

[0037] The integrated test base 100 is made of composite material and has a platform-like structure. An array of force sensors is embedded inside the integrated test base 100. The force sensor array is evenly distributed inside the integrated test base 100. The force sensor array converts force signals into electrical signals through strain gauges or piezoelectric elements. The force sensor array is connected to an external data acquisition system to monitor the force state of the high-voltage current transformer 300 in real time.

[0038] The integrated test base 100 is securely connected to the ground or workbench via anti-vibration fixing bolts 101 at the bottom. An adjustable mechanical fixing fixture is installed around the open support structure, including multiple radially retractable clamping arms 102. Each clamping arm 102 is equipped with an elastic pressure pad and can be adjusted according to the external dimensions of the high-voltage current transformer 300. By uniformly applying radial pressure, the high-voltage current transformer 300 is securely locked onto the open support structure. The clamping arms 102 are connected to the integrated test base 100 via precision slide rails 103, allowing for precise positioning and locking of the high-voltage current transformer 300 after installation, ensuring the high-voltage current transformer 300 maintains a stable position throughout the calibration process.

[0039] A multi-point laser scanning measurement unit 104 is fixedly connected to the integrated test base 100. The multi-point laser scanning measurement unit 104 is arranged in a ring array around the high-voltage current transformer 300. The multi-point laser scanning measurement unit 104 consists of multiple laser ranging sensors. Each laser ranging sensor adopts a miniaturized design and is equipped with a precision optical focusing system, which can accurately measure surface displacement changes without contacting the high-voltage current transformer 300. All sensors are connected to the data fusion analysis unit through a synchronization signal line to ensure the temporal consistency of the measurement data and provide accurate spatial deformation information for thermomechanical coupling analysis.

[0040] The thermomechanical coupling self-calibration system 200 includes two parts: a zoned temperature control unit and a programmable mechanical load applicator, which are used to simultaneously apply a precise temperature field and a mechanical stress field to the high-voltage current transformer 300.

[0041] The zoned temperature control unit includes multiple independently controlled heating zones, which are distributed in a ring around the periphery of the high-voltage current transformer 300. This ring-shaped distribution creates a controllable temperature field around the high-voltage current transformer 300. Each heating zone includes a temperature sensing probe 203 and a heating element 201. Additional temperature sensors are positioned at the boundaries of the heating zones to monitor the temperature gradient between adjacent zones in real time, ensuring a smooth transition across the entire temperature field.

[0042] The programmable mechanical load applicator employs a servo motor-driven pressure arm 202. One end of the pressure arm 202 is connected to the integrated test base 100 via a pressure arm 202 bracket, and the other end has a pressure contact head that matches the surface of the high-voltage current transformer 300. The servo motor is mounted at an appropriate position on the pressure arm 202 and drives it to generate precise pressure via a precision lead screw mechanism. Multiple pressure arms 202 are evenly distributed around the high-voltage current transformer 300, employing a layered, staggered arrangement. The pressure arms 202 form a ring at different height levels, with adjacent pressure arms 202 located at different height levels. The rotation fulcrum of each pressure arm 202 is arranged in a concentric circular array around the integrated test base 100, with the fulcrums maintaining an equal angle. The length, height, and operating angle of the pressure arms 202 are precisely calculated to ensure that adjacent pressure arms 202 do not collide under any operating conditions. The servo motors of each pressure arm 202 are coordinated and controlled by a central controller, employing an anti-collision algorithm to calculate and adjust the movement path of each pressure arm 202 in real time.

[0043] The data fusion analysis unit includes a data acquisition interface, a data processing module, and a model calculation module. The data acquisition interface is connected to the force sensor array, the temperature sensing probe 203, and the calibration circuit to receive raw data from each measurement point.

[0044] In at least one embodiment of the present invention, the workpiece to be tested, namely the high-voltage current transformer 300, is tested using the aforementioned automated calibration device for the high-voltage current transformer 300. The specific testing process is as follows:

[0045] S1, Preparation stage: Install the high-voltage current transformer 300 to be tested onto the integrated test base 100, ensuring that the high-voltage current transformer 300 is firmly in place; connect the primary winding and secondary winding of the high-voltage current transformer 300 to the test circuit, and at the same time confirm that the connections of all sensors and control units are normal.

[0046] Furthermore, after fixing, the initial three-dimensional coordinates of the key points of the high-voltage current transformer 300 are measured by the laser position calibration system. The laser position calibration system achieves precise spatial coordinate positioning through the principles of laser triangulation or interferometry.

[0047] S2, Baseline Data Acquisition: Under ambient temperature and without mechanical load, the high-voltage current transformer 300 is subjected to standard verification tests to obtain performance parameters under baseline conditions, including key indicators such as ratio error and angle error, as reference data for subsequent thermomechanical coupling effect analysis.

[0048] S3, Establishment of laser scanning baseline in the original state: Under ambient temperature and without applying mechanical load, the multi-point laser scanning measurement unit 104 is activated to perform an all-round scan on the surface of the high-voltage current transformer 300, and establish three-dimensional baseline data of the surface morphology of the high-voltage current transformer 300 in the original state, which serves as the original reference point for subsequent thermomechanical deformation analysis.

[0049] S4, Thermomechanical Coupling Environment Construction: Based on the actual working environment parameters of the high-voltage current transformer 300, the target value of temperature distribution is set through the zoned temperature control unit, and the target value of mechanical stress distribution is set through the programmable mechanical load applicator, thus creating a thermomechanical coupling environment that conforms to the actual operating conditions.

[0050] Furthermore, S4 also includes: activating a real-time position monitoring system before applying temperature and mechanical loads. When the system detects that the position deviation of the high-voltage current transformer 300 exceeds a preset threshold, it automatically fine-tunes the pressure distribution of the mechanical fixing fixture, maintaining the positional stability of the high-voltage current transformer 300 throughout the test process through closed-loop control. For high-voltage current transformers 300 made of different materials, the system predicts dimensional changes caused by temperature variations based on their thermal expansion characteristics and pre-compensates for the pre-tightening force applied to the fixture, preventing loosening or over-tightening due to thermal expansion.

[0051] S5, Thermomechanical State Laser Scanning: After applying the initial temperature field and mechanical stress field, the surface of the high-voltage current transformer 300 is scanned again by the multi-point laser scanning measurement unit 104 to obtain the surface morphology data of the high-voltage current transformer 300 under thermomechanical load. By comparing with the original state baseline data, the deformation caused by the initial thermomechanical environment is calculated, providing basic data for subsequent deformation analysis.

[0052] S6, Temperature-Mechanical Stress Coupling Regulation: The data fusion analysis unit calculates the impact of temperature changes on mechanical stress distribution and the reaction of mechanical stress on temperature distribution based on the thermomechanical coupling model. It then adjusts the output parameters of the zoned temperature control unit and the programmable mechanical load applicator in real time to ensure the stability and accuracy of the thermomechanical coupling environment.

[0053] S7, Verification test under coupling environment: In a stable thermomechanical coupling environment, perform the standard verification procedure for the high-voltage current transformer 300 and record the performance parameters of the high-voltage current transformer 300 under different temperature and mechanical stress combinations.

[0054] S8, Real-time Deformation Monitoring and Compensation: The multi-point laser scanning measurement unit 104 continuously monitors the minute deformations on the surface of the high-voltage current transformer 300. The data fusion analysis unit updates the thermomechanical coupling model parameters in real time based on the deformation data, compensates for measurement errors caused by deformation, and improves the accuracy of the verification results.

[0055] S9, Generation of thermomechanical coupling characteristic curves: Based on the verification data under multiple sets of temperature and mechanical stress conditions, the data fusion analysis unit constructs the thermomechanical coupling characteristic curves of the high-voltage current transformer 300, revealing the comprehensive influence of temperature and mechanical stress on the performance of the high-voltage current transformer 300.

[0056] In some embodiments, S6 further includes: the data fusion analysis unit uses an iterative optimization algorithm to find the optimal configuration scheme of the temperature field and the mechanical stress field, so as to minimize the deviation between the simulated environment and the actual working environment of the high-voltage current transformer 300, and improve the ability of the calibration results to predict the actual operating state.

[0057] The data fusion and analysis unit performs the following data analysis and processing steps:

[0058] Step 1: Acquire raw data from multiple sensors to form an initial dataset. In this step, the system simultaneously collects raw data from the force sensor array, temperature sensor probe, multi-point laser scanning measurement unit 104, and high-voltage current transformer 300 calibration circuit. The data is then labeled according to a unified timestamp to form a multi-parameter dataset containing the time dimension.

[0059] Step 2: Process the multi-source sensor data using the Kalman filter algorithm to generate noise-suppressed data. The aforementioned Kalman filter algorithm is a conventional technique in the field of signal processing. Based on the statistical characteristics of measurement noise and system noise, it optimizes and estimates the acquired sensor data through recursive calculations of state equations and measurement equations. This invention applies it to filter out random noise and system errors, thereby improving data reliability.

[0060] Step 3: Perform data synchronization and fusion processing to generate a spatiotemporally aligned comprehensive dataset. In this step, the system establishes spatial mapping relationships and time interpolation functions based on the spatial locations and sampling time differences of each sensor, transforming data from different sources onto a unified coordinate system and time series to form a complete state description of the 300 measurement points of the high-voltage current transformer. The specific implementation is as follows: First, the local measurement coordinates of each sensor are mapped to the global coordinate system of the high-voltage current transformer 300 through a three-dimensional coordinate transformation matrix. The aforementioned three-dimensional coordinate transformation matrix is ​​a conventional technique in the field of spatial geometric transformation. It achieves the transformation between different coordinate systems through rotation and translation matrices. This invention uses it to unify the measurement coordinates of each sensor. The transformation matrix is ​​determined by the sensor spatial position parameters obtained during the initial calibration process. Second, for sensor data of different physical quantities, a data type mapping table is used to clarify the correlation between each physical quantity, such as the correspondence between temperature and thermal strain, and mechanical stress and mechanical strain. Third, a cubic spline interpolation algorithm is used to process data with inconsistent sampling times. The aforementioned cubic spline interpolation algorithm is a conventional technique in the field of numerical analysis. It achieves smooth interpolation between data points by constructing a piecewise homogeneous polynomial. This invention uses it to synchronize sensor data with different sampling rates to ensure that all sensor data have corresponding values ​​at the same time point. Finally, a continuous physical field distribution is constructed on the surface of the high-voltage current transformer 300 through a spatial interpolation algorithm to compensate for the sampling blind spots caused by the discrete arrangement of sensors. All mapping parameters and interpolation coefficients are stored in the configuration database and can be adjusted according to the characteristics of different models of high-voltage current transformers 300.

[0061] Step 4: Analyze the interaction between temperature and stress based on a thermomechanical coupling finite element model, and calculate the theoretical coupling state. This step discretizes the high-voltage current transformer 300 into multiple computational units, and the thermal stress state of each unit is described by the following set of equations:

[0062] ;

[0063] in, Represents the stress tensor. For the elasticity coefficient tensor, For strain tensor, The coefficient of thermal expansion is For temperature changes, Thermal conductivity as a function of temperature and stress For temperature gradient, For material density, For specific heat capacity, , , , These are all subscripts of spatial coordinate components, typically taking values ​​of 1, 2, and 3, corresponding to the three spatial directions of x, y, and z, respectively.

[0064] Step 5: Solve the coupled equations using an iterative calculation method to output the steady-state thermomechanical equilibrium solution. The aforementioned iterative calculation method is a conventional technique in the field of numerical computation. It gradually approximates the solution of the equations by repeatedly executing calculation steps. This invention uses it to solve the thermomechanical coupling equations. The system first calculates the stress field under the initial temperature distribution, and then updates the material parameters based on the stress field to calculate a new temperature field. This process is repeated iteratively until the difference between two adjacent calculation results is less than a preset convergence threshold, thus obtaining the final thermomechanical coupling equilibrium state.

[0065] Step 6: Compare and analyze the measured data with the theoretical calculation results to generate model calibration parameters. This step minimizes the mean square error between the measured data and the model predictions. The aforementioned method for minimizing the mean square error is a conventional technique in the field of parameter optimization. It achieves model fitting by solving for the parameter value that minimizes the sum of squared errors. This invention uses it to optimize key parameters in the thermomechanical coupling model, including the thermal expansion coefficient of the material, stress-sensitive thermal conductivity, and interfacial contact thermal resistance, thereby improving the model's prediction accuracy.

[0066] Step 7: Process the calibration data of the high-voltage current transformer 300 based on the calibrated thermomechanical coupling model to calculate the true metrological characteristics under the influence of thermomechanical coupling. This step uses the model to predict the changes in the ratio error and phase error of the high-voltage current transformer 300 under different temperature and mechanical stress combinations, separates the influence component of thermomechanical coupling effect from the original calibration results, and obtains the intrinsic metrological characteristics of the high-voltage current transformer 300.

[0067] Step 8: Perform regression analysis on the calibration results under multiple operating conditions to establish a performance prediction model for the high-voltage current transformer 300. This step uses temperature distribution parameters and mechanical stress parameters as independent variables, and the corrected metering characteristics of the high-voltage current transformer 300 as the dependent variable. A multivariate nonlinear regression method is employed. This method is a conventional technique in statistical analysis, fitting multivariate nonlinear relationships using the least squares method or other optimization algorithms. This invention uses it to establish a mathematical model of the performance characteristics of the high-voltage current transformer 300 under arbitrary operating conditions for error compensation in subsequent practical applications.

[0068] Step 9: Perform a historical database comparison analysis of the high-voltage current transformer 300 and output the performance comparison results of similar products. This step statistically compares the currently tested performance data of the high-voltage current transformer 300 with the historical data of the same model or specification of high-voltage current transformer 300 in the database, calculates the performance deviation index and anomaly probability, and evaluates the quality level and reliability of the high-voltage current transformer 300.

[0069] Step 10: Generate a comprehensive performance evaluation report for the high-voltage current transformer 300, including numerical results and graphical representations. This step integrates all analysis results and outputs performance parameter tables, error curves, temperature-error relationship diagrams, and stress-error relationship diagrams for the high-voltage current transformer 300 under various operating conditions in a standardized format, providing data support for the rating and usage recommendations of the high-voltage current transformer 300.

[0070] The embodiments of the present invention have been described above. However, the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make more equivalent embodiments under the guidance of the present embodiments, and all of them are within the protection scope of the present embodiments.

Claims

1. A high-voltage current transformer automated calibrating device, characterized in that, include: An integrated test base is used to support the high-voltage current transformer to be calibrated. An open support structure is provided in the central area of ​​the surface. Temperature control elements and a force sensor array are embedded inside the integrated test base. Adjustable mechanical clamps are arranged around the open support structure of the integrated test base to clamp the high-voltage current transformer. The force sensor array is connected to an external data acquisition system to monitor the stress state of the high-voltage current transformer in real time. A multi-point laser scanning measurement unit is fixedly connected to the integrated test base and connected to a data fusion analysis unit through a synchronous signal line to provide accurate spatial deformation information for thermomechanical coupling analysis. The thermomechanical coupling self-calibration system includes a partitioned temperature control unit and a programmable mechanical load applicator, which is used to simultaneously apply a precise temperature field and mechanical stress field to a high-voltage current transformer; The data fusion and analysis unit uses a thermomechanical coupling model for real-time data processing and analysis to construct the performance curves of high-voltage current transformers under specific temperature and mechanical load combinations. The data fusion analysis unit constructs the thermomechanical coupling characteristic curves of the high-voltage current transformer, revealing the comprehensive influence of temperature and mechanical stress on the performance of the high-voltage current transformer. The data fusion analysis unit updates the parameters of the thermomechanical coupling model in real time based on the deformation data to compensate for measurement errors caused by deformation; The partition temperature control unit consists of multiple independently controlled heating zones arranged in a ring to form a regionally controllable temperature field around the high-voltage current transformer. Additional temperature sensors are set at the boundary of the heating zones to monitor the temperature gradient of adjacent zones in real time. The programmable mechanical load applicator uses a pressure arm driven by a multi-point servo motor to apply controllable mechanical stress to the high-voltage current transformer. One end of the pressure arm is connected to the integrated test base via a bracket, and the other end is equipped with a pressure contact head that matches the surface of the high-voltage current transformer.

2. The automated calibration device for high-voltage current transformers according to claim 1, characterized in that, The servo motor is fixedly connected to the pressure arm. The servo motor drives the pressure arm to generate precise pressure through a precision lead screw mechanism. Multiple pressure arms are evenly distributed around the high-voltage current transformer, and the multiple pressure arms adopt a layered staggered arrangement design.

3. The automated calibration device for high-voltage current transformers according to claim 1, characterized in that, The open support structure of the integrated test base includes fixing holes on the integrated test base, which are fixed to the bottom of the high-voltage current transformer by screws. The integrated test base is firmly connected to the ground or workbench by anti-vibration fixing bolts at the bottom for the stability of the integrated test base.

4. The automated calibration device for high-voltage current transformers according to claim 1, characterized in that, The mechanical fixing fixture includes multiple radially telescopic clamping arms, each equipped with an elastic pressure pad that can be adjusted according to the dimensions of the high-voltage current transformer. By uniformly applying radial pressure, the high-voltage current transformer is firmly locked onto the open support structure. The clamping arms are connected to the integrated test base via precision slide rails, which accurately position and lock the high-voltage current transformer after installation.

5. The automated calibration device for high-voltage current transformers according to claim 1, characterized in that, The multi-point laser scanning measurement unit is arranged in a ring array around the high-voltage current transformer. The multi-point laser scanning measurement unit consists of multiple laser ranging sensors, each of which adopts a miniaturized design.

6. The automated calibration device for high-voltage current transformers according to claim 1, characterized in that, Each heating zone of the partitioned temperature control unit includes a temperature sensing probe and a heating element. A gradient heating control scheme is adopted between each heating zone, and a smooth temperature transition between adjacent heating zones is achieved through software algorithms.

7. The automated calibration device for high-voltage current transformers according to claim 2, characterized in that, The pressure arm is made of high-strength alloy material. One end is connected to the integrated test base by a hinge to form a rotation fulcrum. The pressure arm is in a ring at different height levels. Adjacent pressure arms are located at different height levels. The rotation fulcrum of each pressure arm is arranged in a concentric circle array around the integrated test base, and the fulcrums are distributed at equal angles.

8. The automated calibration device for high-voltage current transformers according to claim 1, characterized in that, The data fusion analysis unit includes a data acquisition interface, a data processing module, and a model calculation module, which are connected in sequence. The model calculation module analyzes the mechanical deformation caused by temperature changes and the temperature distribution changes caused by mechanical stress based on the thermomechanical coupling theory.

9. The automated calibration device for high-voltage current transformers according to claim 2, characterized in that, The servo motors of each pressure arm are controlled collaboratively by a central controller, and an anti-collision algorithm is used to calculate and adjust the movement path of each pressure arm in real time.

10. A method for calibrating a high-voltage current transformer using the automated calibration device according to any one of claims 1-9, characterized in that, include: Baseline data was collected at ambient temperature. A thermomechanical coupling environment is constructed using zoned temperature control units and programmable mechanical load applicators; Verification tests are performed under thermomechanical coupling conditions; surface deformation is monitored by a multi-point laser scanning measurement unit, and the data fusion analysis unit processes and corrects the data based on the thermomechanical coupling model to generate thermomechanical coupling characteristic curves.

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