Method, apparatus, system, device and medium for calibrating a conductor magnetic field sensor array

Abstract

The application discloses a kind of correcting method, device, system, equipment and medium of conductor magnetic field sensor array, belong to the field of sensor correction, the method is: obtaining N groups of magnetic induction parameters, each group of magnetic induction parameters is closed conductor when energized, magnetic induction intensity is collected by the magnetic field sensor array around the conductor, N≥1;Each group of magnetic induction parameters is transformed to obtain transformation parameter, and the phase offset of magnetic field sensor is calculated using transformation parameter;A plurality of phase offsets and transformation parameters are substituted into a predetermined optimization model to solve, to obtain correction parameter, the predetermined optimization model is the calculation model of nonlinear least squares optimization problem.This application can obtain parameters for offline correction, can let conductor no longer be affected by sensor error, can realize the high-precision calibration of sensor parameter, to improve the precision of correction, and the whole process does not need to access, can also avoid the deviation of parameter due to mechanical assembly error.

Description

Technical Field

[0001] This invention relates to the technical field of sensor calibration, and in particular to a calibration method, apparatus, system, device, and medium for a conductor magnetic field sensor array. Background Technology

[0002] In power systems, non-invasive current measurement of enclosed conductor systems (such as three-core cables and distribution lines within bushings) is a critical requirement and a core technology in power systems, industrial automation, and energy management. Multiple magnetic field sensors are deployed in the external space of the conductor to form a sensor array. The internal current of each conductor is retrieved based on the spatial magnetic field distribution, and then used for grid monitoring, energy consumption analysis, and equipment condition assessment.

[0003] However, with the development of smart grids and advanced power electronic equipment, the accuracy requirements for current measurement are becoming increasingly stringent. The measurement accuracy of non-invasive technologies directly depends on the calibration accuracy of the sensor's spatial geometry and electrical characteristics. To meet measurement requirements, the sensor's geometric position and electrical parameters need to be calibrated. One commonly used calibration method is mechanical calibration, which involves using precision mechanical equipment to detect the sensor's position and then calibrating it at the measurement site using a known current source.

[0004] However, the above methods have the following technical problems: Precision mechanical equipment testing requires destructive access or known conductor location, which is not suitable for closed conductor systems (such as wires in cables or conduits); moreover, both equipment testing and field measurement may be affected by mechanical assembly errors and the dispersion of circuit parameters, resulting in deviations in the actual parameters of the sensors, which affects the accuracy of subsequent current inversion. Summary of the Invention

[0005] This invention provides a calibration method, apparatus, device, and medium for a conductor magnetic field sensor array, which can solve one or more technical problems existing in the prior art.

[0006] A first aspect of this invention provides a calibration method for a conductor magnetic field sensor array, the method comprising: Obtain N sets of magnetic induction parameters, wherein each set of magnetic induction parameters is the magnetic induction intensity collected by the magnetic field sensor array around the closed conductor when the conductor is energized, and N≥1; The transformation parameters are obtained by transforming each set of magnetic induction parameters, and the phase shift of the magnetic field sensor is calculated using the transformation parameters. The phase offsets and transformation parameters are substituted into a preset optimization model for solution to obtain the correction parameters. The preset optimization model is a computational model for a nonlinear least squares optimization problem.

[0007] In conjunction with the first aspect, in one implementation, the step of transforming each set of magnetic induction parameters to obtain transformation parameters, and using the transformation parameters to calculate the phase shift of the magnetic field sensor, includes: For each set of magnetic induction parameters, an analog-to-digital conversion is performed to obtain digital-to-analog parameters, wherein the digital-to-analog parameters include: digital voltage values ​​and digital current values; The analog-to-digital parameters are subjected to a Fourier transform to obtain transform parameters, wherein the transform parameters include: voltage amplitude, voltage vector, current amplitude, and current vector; The phase shift is obtained by calculating the difference between the voltage vector and the current vector.

[0008] In conjunction with the first aspect, in one implementation, the step of performing analog-to-digital conversion on each set of magnetic induction parameters to obtain digital-to-analog parameters includes: The magnetic induction parameters are converted into an electromotive force in the millivolt range; The electromotive force is amplified using a preset integrating amplifier circuit to obtain an analog signal; The analog signal is converted from analog to digital to obtain digital-to-analog parameters.

[0009] In conjunction with the first aspect, in one implementation, the step of substituting several phase offsets and the transformation parameters into a preset optimization model for solution to obtain correction parameters includes: Obtain auxiliary variables, wherein the auxiliary variables are the output voltage of any one sensor in the magnetic field sensor array of any calibration experiment; Substitute the auxiliary variables, the M phase offsets, and the M sets of transformation parameters into the preset optimization model, and solve the objective function of the preset optimization model based on the preset constraints to obtain the correction parameters; The preset constraints include: parameter range constraints, position tolerance constraints, and physical model equality constraints, with M≥4.

[0010] In conjunction with the first aspect, in one implementation, the operation of obtaining the magnetic induction parameters includes: Each time the conductor is inserted into the positioning hole, AC current is applied to the conductor to energize it; The magnetic induction intensity is collected by an array of magnetic field sensors around the conductor to obtain magnetic induction parameters.

[0011] A second aspect of the present invention provides a calibration device for a conductor magnetic field sensor array, the device comprising: The acquisition module is used to acquire N sets of magnetic induction parameters, wherein each set of magnetic induction parameters is the magnetic induction intensity collected by the magnetic field sensor array around the closed conductor when the conductor is energized, and N≥1; The calculation module is used to transform each set of magnetic induction parameters to obtain transformation parameters, and to use the transformation parameters to calculate the phase shift of the magnetic field sensor. The correction module is used to substitute several phase offsets and transformation parameters into a preset optimization model for solving to obtain correction parameters. The preset optimization model is a computational model for a nonlinear least squares optimization problem.

[0012] In conjunction with the second aspect, in one implementation, the step of transforming each set of magnetic induction parameters to obtain transformation parameters, and using the transformation parameters to calculate the phase shift of the magnetic field sensor, includes: For each set of magnetic induction parameters, an analog-to-digital conversion is performed to obtain digital-to-analog parameters, wherein the digital-to-analog parameters include: digital voltage values ​​and digital current values; The analog-to-digital parameters are subjected to a Fourier transform to obtain transform parameters, wherein the transform parameters include: voltage amplitude, voltage vector, current amplitude, and current vector; The phase shift is obtained by calculating the difference between the voltage vector and the current vector.

[0013] In conjunction with the second aspect, in one implementation, the step of performing analog-to-digital conversion on each set of magnetic induction parameters to obtain digital-to-analog parameters includes: The magnetic induction parameters are converted into an electromotive force in the millivolt range; The electromotive force is amplified using a preset integrating amplifier circuit to obtain an analog signal; The analog signal is converted from analog to digital to obtain digital-to-analog parameters.

[0014] In conjunction with the second aspect, in one implementation, the step of substituting several phase offsets and the transformation parameters into a preset optimization model for solution to obtain correction parameters includes: Obtain auxiliary variables, wherein the auxiliary variables are the output voltage of any one sensor in the magnetic field sensor array of any calibration experiment; Substitute the auxiliary variables, the M phase offsets, and the M sets of transformation parameters into the preset optimization model, and solve the objective function of the preset optimization model based on the preset constraints to obtain the correction parameters; The preset constraints include: parameter range constraints, position tolerance constraints, and physical model equality constraints, with M≥4.

[0015] In conjunction with the second aspect, in one implementation, the operation of obtaining the magnetic induction parameters includes: Each time the conductor is inserted into the positioning hole, AC current is applied to the conductor to energize it; The magnetic induction intensity is collected by an array of magnetic field sensors around the conductor to obtain magnetic induction parameters.

[0016] A third aspect of the present invention provides a calibration system for a conductor magnetic field sensor array, the system comprising: The control unit comprises a control unit, one or more positioning holes, and a magnetic field sensor array, wherein the control unit is communicatively connected to the magnetic field sensor array and performs the calibration method for the conductor magnetic field sensor array as described above. The positioning hole is used to place the conductor, and the magnetic field sensor array is arranged around the positioning hole.

[0017] In conjunction with the third aspect, in one implementation, the magnetic field sensor array includes an array housing and a plurality of magnetic field sensors; A plurality of magnetic field sensors are disposed within the array housing, and the plurality of magnetic field sensors are spaced apart from each other. The array housing is disposed around the positioning hole, so that the magnetic field sensors receive magnetic induction parameters when the conductors in the positioning hole are energized.

[0018] Compared to existing technologies, the present invention provides a calibration method, apparatus, device, and medium for a conductor magnetic field sensor array, which offers the following advantages: The present invention can acquire N sets of magnetic induction parameters, each set representing the magnetic induction intensity collected by a magnetic field sensor array around a closed conductor when the conductor is energized. Each set of magnetic induction parameters is transformed to obtain transformed parameters, and the phase shift of the magnetic field sensor is calculated using these transformed parameters. Several phase shifts and transformed parameters are substituted into a preset optimization model for solution to obtain calibration parameters. The present invention allows for offline parameter calibration, freeing the conductor from sensor errors and enabling high-precision calibration of sensor parameters to improve calibration accuracy. Furthermore, the entire process requires no external connection, avoiding parameter deviations caused by mechanical assembly errors. Attached Figure Description

[0019] Figure 1 This is a schematic flowchart of a calibration method for a conductor magnetic field sensor array provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the geometric structure of a magnetic field sensor and a conductor provided in an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the effect of determining the number of solutions by evaluating local and global correction errors according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a calibration device for a conductor magnetic field sensor array according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a calibration system for a conductor magnetic field sensor array provided in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In power systems, non-invasive current measurement of enclosed conductor systems (such as three-core cables and distribution lines within bushings) is a critical requirement and a core technology in power systems, industrial automation, and energy management. Multiple magnetic field sensors are deployed in the external space of the conductor to form a sensor array. The internal current of each conductor is retrieved based on the spatial magnetic field distribution, and then used for grid monitoring, energy consumption analysis, and equipment condition assessment.

[0022] However, with the development of smart grids and advanced power electronic equipment, the accuracy requirements for current measurement are becoming increasingly stringent. The measurement accuracy of non-invasive technologies directly depends on the calibration accuracy of the sensor's spatial geometry and electrical characteristics. To meet measurement requirements, the sensor's geometric position and electrical parameters need to be calibrated. One commonly used calibration method is mechanical calibration, which involves using precision mechanical equipment to detect the sensor's position and then calibrating it at the measurement site using a known current source.

[0023] However, the above methods have the following technical problems: Precision mechanical equipment testing requires destructive access or known conductor location, which is not suitable for closed conductor systems (such as wires in cables or conduits); moreover, both equipment testing and field measurement may be affected by mechanical assembly errors and the dispersion of circuit parameters, resulting in deviations in the actual parameters of the sensors, which affects the accuracy of subsequent current inversion.

[0024] To address the aforementioned issues, the following detailed description and explanation will be provided through specific embodiments of a calibration method, apparatus, device, and medium for a conductor magnetic field sensor array provided in this application.

[0025] To solve one or more technical problems existing in the prior art, referring to Figure 1 The diagram shows a flowchart illustrating a calibration method for a conductor magnetic field sensor array according to an embodiment of the present invention.

[0026] As an example, the calibration method for the conductor magnetic field sensor array may include: S11. Obtain N sets of magnetic induction parameters, wherein each set of magnetic induction parameters is the magnetic induction intensity collected by the magnetic field sensor array around the closed conductor when the conductor is energized, and N≥1.

[0027] In one embodiment, when calibration is required, N sets of magnetic induction parameters can be obtained, where N is a positive integer greater than or equal to 1. Each set of magnetic induction parameters is obtained by collecting the magnetic induction intensity generated by the conductor from a magnetic field sensor array around the conductor when the conductor is energized.

[0028] As an example, the operation of obtaining the magnetic induction parameters may include the following sub-steps: S111. Each time the conductor is inserted into the positioning hole, AC current is input to the conductor to energize it.

[0029] S112. The magnetic induction intensity is collected by a magnetic field sensor array around the conductor to obtain the magnetic induction parameters.

[0030] In one embodiment, alternating current can be supplied to the conductor to energize it whenever the conductor is inserted into the positioning hole.

[0031] In one operating mode, the conductor can be a wire, which serves as the signal source for the correction system, through which an alternating current with precisely controllable amplitude and phase is passed at a known location, so that the conductor can generate a standard, traceable magnetic field.

[0032] In one embodiment, a calibration pipe can be pre-set, which serves as the structural reference and positioning carrier of the calibration system. The pipe has a precise positioning installation structure (such as a positioning hole) inside for fixing the calibration wire.

[0033] The magnetic field sensor, as the sensing unit of the calibration system, is used to accurately detect the magnetic field strength generated by the current in the calibration conductor and convert it into an electrical signal output.

[0034] It should be noted that the present invention can be applied to a closed conductor system, and the conductor used can be one or more conductors.

[0035] Optionally, when passing an alternating current through the correction conductor, the magnitude of the current (amplitude and phase are controllable) can be changed by altering the load power.

[0036] In practice, the position of the calibration conductor's positioning hole within the pipe can be moved or changed. Each change in position serves as a set of calibration experiments to obtain a set of magnetic induction parameters. Furthermore, the conductor coordinates (xi, yi) and current phasor Îi at all positions are known and precise values.

[0037] S12. Transform each set of magnetic induction parameters to obtain transformation parameters, and use the transformation parameters to calculate the phase shift of the magnetic field sensor.

[0038] Since the magnetic induction parameters are analog signals collected by the magnetic field sensor, the magnetic induction parameters can be transformed to obtain transformed parameters. Then, the phase shift of each magnetic field sensor can be calculated using the transformed parameters. This phase shift is the phase deviation value of the voltage and current of each magnetic field sensor.

[0039] In an optional embodiment, the step of transforming each set of magnetic induction parameters to obtain transformation parameters and using the transformation parameters to calculate the phase shift of the magnetic field sensor may include the following sub-steps: S121. Perform analog-to-digital conversion on each group of magnetic induction parameters to obtain digital-to-analog parameters, wherein the digital-to-analog parameters include: digital voltage value and digital current value.

[0040] S122. Perform a Fourier transform on the digital-analog parameters to obtain transform parameters, wherein the transform parameters include: voltage amplitude, voltage vector, current amplitude, and current vector.

[0041] S123. Calculate the difference between the voltage vector and the current vector to obtain the phase offset.

[0042] In one embodiment, since the magnetic induction parameters are analog signals collected by a magnetic field sensor, the magnetic induction parameters can be converted from analog to digital to obtain digital-analog parameters, wherein the digital-analog parameters include: digital voltage values ​​and digital current values.

[0043] Next, a Fourier transform can be performed on the analog-digital parameters to obtain the transform parameters, which include: voltage amplitude, voltage vector, current amplitude, and current vector.

[0044] Finally, the difference between the voltage vector and the current vector can be calculated to obtain the phase shift. It can be obtained by measuring the average phase difference between current and voltage phasors.

[0045] In one embodiment, phase shift The calculation can be shown in the following formula: In the above formula, For phase shift, For the first k The magnetic field sensor, in the first j Voltage vector of magnetic induction parameters collected in the secondary correction experiment. It is a current phasor.

[0046] In one embodiment, the step of performing analog-to-digital conversion on each set of magnetic induction parameters to obtain digital-to-analog parameters may include the following sub-steps: S1211. Convert the magnetic induction parameters into a millivolt-level electromotive force.

[0047] S1212. The electromotive force is amplified using a preset integrating amplifier circuit to obtain an analog signal.

[0048] S1213. Perform analog-to-digital conversion on the analog signal to obtain digital-to-analog parameters.

[0049] Reference Figure 2 The diagram shows a geometric structure of a magnetic field sensor and a conductor provided in an embodiment of the present invention.

[0050] For an infinitely long straight conductor, the magnetic effect of electric current indicates that the alternating current in a single conductor of a cable will generate an alternating magnetic field around the conductor. Based on Faraday's law of magnetic induction, the generated alternating magnetic field will induce an electromotive force in the induction coil.

[0051] Figure 2 The relationship between the conductor and the magnetic field sensor's position is illustrated. It can be noted that the ideal sensing direction of the designed magnetic field sensor is the tangent to the arc centered at the origin. However, due to installation deviations, the actual direction will deviate by a certain angle. The magnetic flux density sensed by the magnetic field sensor is the value projected onto the sensing direction of the magnetic field sensor by the magnetic flux density generated by the conductor current, and its expression can be shown in the following formula: ; in, For the current phasor of the conductor, r The distance between the conductor and the magnetic field sensor. The projection angle is the magnetic induction intensity.

[0052] Based on this, the alternating magnetic field generated by the current induces an electromotive force in the magnetic field sensor, and the induced electromotive force can be obtained from the following formula: ; Since a magnetic field sensor outputs a millivolt-level induced electromotive force (EMF) by sensing a magnetic field, the acquired EMF can be input into an integrating amplifier circuit to obtain an output voltage. The analog signal is obtained, and the expression for the output voltage is: ; in, ρ and  These represent the amplification factor and phase shift caused by the magnetic field sensor and the integrating amplifier circuit, respectively.

[0053] In the above expression for output voltage, due to the change in conductor position, r With cos δ The value will also change, at which point the invariant sensor coordinates related to the magnetic field sensor should be used. , ) and offset angle  and related variable conductor position ( , ) to replace r and cos δ .

[0054] The goal of magnetic field sensor calibration is to find the target for the first k Specific parameters of each sensor, including the gain coefficient of the magnetic field sensor. Phase shift The coordinates of the magnetic field sensor in the measurement plane ( , ) and sensor measuring orientation angle To simplify the process and avoid interference between conductors, each calibration procedure can use only one conductor. The number of single-conductor calibration experiments is denoted as... This constitutes the correction dataset. A set of coordinates of the conductors and current phasors. Known.

[0055] Will r Using the position coordinates of the conductor and sensor ( , )and( , To represent it. cos δ The position coordinates of the conductor and the magnetic field sensor ( , )and( , and the sensor offset from the ideal direction angle  To represent this, we can substitute the above parameters into the expression for the output voltage, and obtain: ; In the above formula, This is the analog signal output by the k-th sensor during the j-th calibration test.

[0056] Since the output voltage is an analog signal, it can be converted into a digital signal by an ADC (analog-to-digital converter), and the output voltage data can be saved using LabVIEW software.

[0057] S13. Substitute several phase offsets and transformation parameters into a preset optimization model for solution to obtain correction parameters. The preset optimization model is a computational model for a nonlinear least squares optimization problem.

[0058] In one embodiment, the phase shift and transformation parameters (including voltage amplitude, voltage vector, current amplitude, and current vector) can be obtained through the above calculations. A single phase shift and one transformation parameter can be substituted into a preset optimization model for solution to obtain the correction parameters. Alternatively, several phase shifts and their corresponding transformation parameters can be substituted into the preset optimization model for solution to obtain the correction parameters. The preset optimization model is a computational model for a nonlinear least squares optimization problem.

[0059] In one embodiment, substituting the plurality of phase offsets and the transformation parameters into a preset optimization model for solving to obtain the correction parameters may include the following sub-steps: S131. Obtain auxiliary variables, wherein the auxiliary variables are the output voltage of any sensor in the magnetic field sensor array of any calibration experiment.

[0060] S132. Substitute the auxiliary variables, the M phase offsets, and the M sets of transformation parameters into the preset optimization model, and solve the objective function of the preset optimization model based on the preset constraints to obtain the correction parameters. The preset constraints include: parameter range constraints, position tolerance constraints, and physical model equality constraints, with M≥4.

[0061] In one embodiment, a pre-defined optimization model for a nonlinear least squares (NLLS) optimization problem can be constructed and solved to determine... , , and .

[0062] In one embodiment, code is written according to the formula of the preset optimization model. The above nonlinear least squares formula is solved using the Python Pyoomo nonlinear programming tool, and IPOPT is used as the optimizer to solve the problem and obtain the correction parameters.

[0063] To reduce the nonlinearity of the equation system, auxiliary variables are introduced. This variable represents the first j Secondary calibration experiment (conductor position is) ) No. k The output voltage of each sensor.

[0064] Objective function: Minimize the voltage calculated according to the preset optimization model in all calibration experiments. With actual measured voltage The sum of squared amplitude errors.

[0065] The optimization variables for obtaining the correction parameters include: , , , .

[0066] The constraints for solving the problem are as follows: 1. Parameter range constraints: , ; 2. Position tolerance constraint: The calibrated sensor position ( , It must be installed at the nominal installation location ( , ( ) represents the center and the allowable radius. R S Inside the circle, that is ; 3. For each calibration experiment j The magnetic field induced voltage calculation formula must be satisfied, and it is expressed as an equality constraint and introduced into the optimization.

[0067] After solving the optimization problem, the calibration parameters for each sensor are obtained. The complete set of calibration parameters includes: , , , , ,in, and These are the coordinates of the magnetic field sensor. It is the gain of the magnetic field sensor. This refers to the orientation angle of the magnetic field sensor. The calibrated parameters can be stored in the device's memory chip for use in all subsequent measurement tasks.

[0068] Reference Figure 3 This illustration shows the effect of determining the number of solutions by evaluating local and global correction errors according to an embodiment of the present invention. Figure 3 As shown, the calibrated conductor and the uncalibrated conductor refer to the positions used and not used during calibration, respectively.

[0069] For the number of calibration samples (i.e., M), theoretically there are 4 unknown parameters, and at least 4 sets of calibration data are required. In reality, due to noise and uncertainty, more data is needed to reduce overfitting and global error. Experiments show that 10 sets of calibration data can achieve a good balance between fitting accuracy and computational efficiency.

[0070] It's important to note that the entire process can begin with sensor calibration, followed by measurement of any conductor. The sensor's own parameters are accurately measured offline, and on-site calibration only requires inverting the conductor current to achieve offline correction. This method eliminates the influence of sensor errors on the conductor, enabling high-precision sensor parameter calibration. Furthermore, through multi-conductor coupling, magnetic field superposition, and current decoupling, the calibration results are made independent of the measured object, significantly improving the versatility and applicability of the sensor array. The entire process simplifies user operations and reduces on-site deployment difficulty and maintenance costs through a one-time calibration and permanent use model. Moreover, nonlinear optimization and multi-location sampling strategies effectively suppress random measurement noise and systematic errors, improving the robustness and reliability of parameter identification.

[0071] In this embodiment, the present invention provides a calibration method for a conductor magnetic field sensor array. Its advantages are as follows: The present invention can acquire N sets of magnetic induction parameters, each set being the magnetic induction intensity collected by a magnetic field sensor array around a closed conductor when the conductor is energized; each set of magnetic induction parameters is transformed to obtain transformed parameters, and the phase shift of the magnetic field sensor is calculated using these transformed parameters; several phase shifts and transformed parameters are substituted into a preset optimization model for solution to obtain calibration parameters. The present invention allows for offline calibration of parameters, freeing the conductor from the influence of sensor errors, enabling high-precision calibration of sensor parameters to improve calibration accuracy. Furthermore, the entire process requires no external intervention and avoids parameter deviations caused by mechanical assembly errors.

[0072] This invention also provides a calibration device for a conductor magnetic field sensor array, see [link to documentation]. Figure 4 The diagram shows a structural schematic of a calibration device for a conductor magnetic field sensor array according to an embodiment of the present invention.

[0073] As an example, the calibration device for the conductor magnetic field sensor array may include: The acquisition module 201 is used to acquire N sets of magnetic induction parameters, wherein each set of magnetic induction parameters is the magnetic induction intensity collected by the magnetic field sensor array around the closed conductor when the conductor is energized, and N≥1; The calculation module 202 is used to transform each set of magnetic induction parameters to obtain transformation parameters, and to use the transformation parameters to calculate the phase shift of the magnetic field sensor. The correction module 203 is used to substitute several phase offsets and transformation parameters into a preset optimization model for solving to obtain correction parameters. The preset optimization model is a computational model for a nonlinear least squares optimization problem.

[0074] Optionally, the step of transforming each set of magnetic induction parameters to obtain transformation parameters, and using the transformation parameters to calculate the phase shift of the magnetic field sensor, includes: For each set of magnetic induction parameters, an analog-to-digital conversion is performed to obtain digital-to-analog parameters, wherein the digital-to-analog parameters include: digital voltage values ​​and digital current values; The analog-to-digital parameters are subjected to a Fourier transform to obtain transform parameters, wherein the transform parameters include: voltage amplitude, voltage vector, current amplitude, and current vector; The phase shift is obtained by calculating the difference between the voltage vector and the current vector.

[0075] Optionally, the step of performing analog-to-digital conversion on each set of magnetic induction parameters to obtain digital-to-analog parameters includes: The magnetic induction parameters are converted into an electromotive force in the millivolt range; The electromotive force is amplified using a preset integrating amplifier circuit to obtain an analog signal; The analog signal is converted from analog to digital to obtain digital-to-analog parameters.

[0076] Optionally, the step of substituting several phase offsets and transformation parameters into a preset optimization model for solution to obtain correction parameters includes: Obtain auxiliary variables, wherein the auxiliary variables are the output voltage of any one sensor in the magnetic field sensor array of any calibration experiment; Substitute the auxiliary variables, the M phase offsets, and the M sets of transformation parameters into the preset optimization model, and solve the objective function of the preset optimization model based on the preset constraints to obtain the correction parameters; The preset constraints include: parameter range constraints, position tolerance constraints, and physical model equality constraints, with M≥4.

[0077] Optionally, the operation of obtaining the magnetic induction parameters includes: Each time the conductor is inserted into the positioning hole, AC current is applied to the conductor to energize it; The magnetic induction intensity is collected by an array of magnetic field sensors around the conductor to obtain magnetic induction parameters.

[0078] This invention also provides a calibration system for a conductor magnetic field sensor array, see [link to documentation]. Figure 3 The diagram shows a structural schematic of a calibration system for a conductor magnetic field sensor array according to an embodiment of the present invention.

[0079] As an example, the calibration system for the conductor magnetic field sensor array may include: a control unit, one or more positioning holes 3 and a magnetic field sensor array 1, wherein the control unit is communicatively connected to the magnetic field sensor array 1, and the control unit executes the calibration method for the conductor magnetic field sensor array as described in the above embodiments; The positioning hole 3 is used to place the conductor 2, and the magnetic field sensor array 1 is arranged around the positioning hole 3.

[0080] In conjunction with the third aspect, in one implementation, the magnetic field sensor array 1 includes an array housing and a plurality of magnetic field sensors; A plurality of magnetic field sensors are disposed within the array housing, and the plurality of magnetic field sensors are spaced apart from each other. The array housing is disposed around the positioning hole 3, so that the magnetic field sensors receive magnetic induction parameters when the conductor 2 in the positioning hole 3 is energized.

[0081] Specifically, the control unit can be installed in the magnetic field sensor. After the magnetic field sensor collects data, it can transmit the data to the control unit for calibration processing.

[0082] Optionally, the control unit may include: an integrating amplifier circuit module, a power supply module (providing ±5V voltage), and a data interface module.

[0083] In one operating method, the hardware deployment begins by mounting SDR0302-102KL magnetic field sensors in a U-shaped array on a PCB circuit board, evenly distributed. Then, 3D-printed conductor positioning tubes are placed inside the U-shaped circuit board. Next, the magnetic field sensors, integrating amplifier circuit module, power supply module (providing ±5V voltage), and data interface module are connected sequentially, and the left and right circuit boards are connected via DuPont wires.

[0084] Finally, the output voltage signal of the magnetic field sensor is connected to the NI data acquisition card (NI9215 / 9221) through the data interface module, and then connected to the PC. At the same time, the FLUKE i200s current clamp is connected to the conductor under test as a reference current measurement standard.

[0085] Secondly, the wiring configuration adopts a single-conductor wiring method, which involves connecting any 220V wire from the three-phase power supply to an aluminum rod on the positioning tube. This aluminum rod is connected to one phase of the load, and the power supply neutral wire is connected to the load neutral wire, thereby constructing a standard single-conductor measurement circuit for subsequent calibration experiments.

[0086] Next, current is applied. A 220V three-phase voltage source is turned on to energize the experimental conductors, and the current magnitude is changed by altering the load power. During the experiment, aluminum rods are placed sequentially at different conductor positions on the positioning tube, and calibration measurements are performed at each position, with each position serving as an independent calibration experimental group.

[0087] Next comes data acquisition. The integrating amplifier circuit first amplifies the millivolt-level signal sensed by the sensor to the volt level. Then, the ADC (Analog-to-Digital Converter) converts the analog voltage signal into a digital signal, and the output voltage data is saved using LabVIEW software. Simultaneously, a current clamp is used to measure the actual current of a single conductor at the same location as a reference value, which is also input into the PC and saved via a data acquisition card. After acquisition, Fourier transforms are performed on the voltage and current digital signals to obtain the corresponding voltage and current amplitudes and phase angles.

[0088] Next, the parameters are calculated, and the nonlinear least squares method is used for parameter correction.

[0089] Finally, the results are stored and applied. The calculated sensor parameters are used as known inputs for subsequent multi-core cable current identification algorithms, and are used for actual multi-conductor current measurement calculations.

[0090] In a preferred embodiment, the number of magnetic field sensors can be 10, which can be placed evenly, since the positions can all be measured.

[0091] It should be noted that the core algorithm of this invention is the NLLS nonlinear least squares optimization algorithm, which uses Python pyomo and IPOPT as optimizers to complete the solution. Theoretically, at least 4 sets of calibration data are required, but in actual engineering, 10 sets of calibration data can achieve the optimal balance between fitting accuracy and computational efficiency.

[0092] Moreover, the calibration only obtains the sensor's own inherent parameters (position, gain, phase shift, etc.), which are independent of the number of conductors; the multi-conductor magnetic field coupling decoupling is completed in the subsequent multi-conductor current inversion algorithm, and the calibration process only calibrates the sensor itself, without coupling interference issues.

[0093] Based on this, the present invention can achieve complete decoupling of sensor parameters from the system under test, support offline production-end calibration, and be ready to use on-site without the need for destructive calibration on-site. At the same time, it takes into account both high precision and low cost, and is perfectly adapted to the measurement scenarios of multi-conductor systems that have been laid, are closed and inaccessible.

[0094] Those skilled in the art will understand that, for ease of description and brevity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0095] Furthermore, this application also provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the calibration method for the conductor magnetic field sensor array as described in the above embodiments.

[0096] Furthermore, embodiments of this application also provide a computer-readable storage medium storing a computer-executable program for causing a computer to perform the calibration method for the conductor magnetic field sensor array as described in the above embodiments.

[0097] In the description of the embodiments of the present invention, it should be noted that the terms "above," "below," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. When an element such as a layer, region, or substrate is referred to as being "above" or "on top of" another element, it may be directly on the other element, or there may be an intermediate element. Conversely, when an element is referred to as being "directly on" or "above" another element, there is no intermediate element. It should also be understood that when an element is referred to as being "below" or "under" another element, it may be directly below or under the other element, or there may be an intermediate element. Conversely, when an element is referred to as being "directly below" or "under" another element, there is no intermediate element. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0098] Those skilled in the art will understand that embodiments of this application may also include computer program products. Therefore, this application may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0099] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), devices, and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0100] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0101] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0102] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A calibration method for a conductor magnetic field sensor array, characterized in that, The method includes: Obtain N sets of magnetic induction parameters, wherein each set of magnetic induction parameters is the magnetic induction intensity collected by the magnetic field sensor array around the closed conductor when the conductor is energized, and N≥1; The transformation parameters are obtained by transforming each set of magnetic induction parameters, and the phase shift of the magnetic field sensor is calculated using the transformation parameters. The phase offsets and transformation parameters are substituted into a preset optimization model for solution to obtain the correction parameters. The preset optimization model is a computational model for a nonlinear least squares optimization problem.

2. The calibration method for a conductor magnetic field sensor array according to claim 1, characterized in that, The process of transforming each set of magnetic induction parameters to obtain transformation parameters, and using the transformation parameters to calculate the phase shift of the magnetic field sensor, includes: For each set of magnetic induction parameters, an analog-to-digital conversion is performed to obtain digital-to-analog parameters, wherein the digital-to-analog parameters include: digital voltage values ​​and digital current values; The analog-to-digital parameters are subjected to a Fourier transform to obtain transform parameters, wherein the transform parameters include: voltage amplitude, voltage vector, current amplitude, and current vector; The phase shift is obtained by calculating the difference between the voltage vector and the current vector.

3. The calibration method for a conductor magnetic field sensor array according to claim 2, characterized in that, The step of performing analog-to-digital conversion on each set of magnetic induction parameters to obtain digital-to-analog parameters includes: The magnetic induction parameters are converted into an electromotive force in the millivolt range; The electromotive force is amplified using a preset integrating amplifier circuit to obtain an analog signal; The analog signal is converted from analog to digital to obtain digital-to-analog parameters.

4. The calibration method for a conductor magnetic field sensor array according to claim 1, characterized in that, The step of substituting several phase offsets and transformation parameters into a preset optimization model for solution to obtain correction parameters includes: Obtain auxiliary variables, wherein the auxiliary variables are the output voltage of any one sensor in the magnetic field sensor array of any calibration experiment; Substitute the auxiliary variables, the M phase offsets, and the M sets of transformation parameters into the preset optimization model, and solve the objective function of the preset optimization model based on the preset constraints to obtain the correction parameters; The preset constraints include: parameter range constraints, position tolerance constraints, and physical model equality constraints, with M≥4.

5. The calibration method for a conductor magnetic field sensor array according to any one of claims 1-4, characterized in that, The operation of obtaining the magnetic induction parameters includes: Each time the conductor is inserted into the positioning hole, AC current is applied to the conductor to energize it; The magnetic induction intensity is collected by an array of magnetic field sensors around the conductor to obtain magnetic induction parameters.

6. A calibration device for a conductor magnetic field sensor array, characterized in that, The device includes: The acquisition module is used to acquire N sets of magnetic induction parameters, wherein each set of magnetic induction parameters is the magnetic induction intensity collected by the magnetic field sensor array around the closed conductor when the conductor is energized, and N≥1; The calculation module is used to transform each set of magnetic induction parameters to obtain transformation parameters, and to use the transformation parameters to calculate the phase shift of the magnetic field sensor. The correction module is used to substitute several phase offsets and transformation parameters into a preset optimization model for solving to obtain correction parameters. The preset optimization model is a computational model for a nonlinear least squares optimization problem.

7. A calibration system for a conductor magnetic field sensor array, characterized in that, The system includes: a control unit, one or more positioning holes and a magnetic field sensor array, wherein the control unit is communicatively connected to the magnetic field sensor array, and the control unit performs the calibration method for the conductor magnetic field sensor array as described in any one of claims 1-5; The positioning hole is used to place the conductor, and the magnetic field sensor array is arranged around the positioning hole.

8. The calibration system for the conductor magnetic field sensor array according to claim 7, characterized in that, The magnetic field sensor array includes an array housing and several magnetic field sensors; A plurality of magnetic field sensors are disposed within the array housing, and the plurality of magnetic field sensors are spaced apart from each other. The array housing is disposed around the positioning hole, so that the magnetic field sensors receive magnetic induction parameters when the conductors in the positioning hole are energized.

9. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the program, it implements the calibration method for a conductor magnetic field sensor array as described in any one of claims 1-5.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the calibration method for the conductor magnetic field sensor array as described in any one of claims 1-5.

Images