Multi-conductor non-intrusive current measurement method, system and device based on low-noise sensor and storage medium
By using a low-noise magnetic field sensor array to detect the magnetic field signal of a multi-conductor cable, noise reduction and reverse adjustment are performed, solving the accuracy and efficiency problems in non-invasive current measurement of multi-conductors, and realizing high-precision current measurement and fault diagnosis support.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUIZHOU POWER GRID CO LTD
- Filing Date
- 2025-12-25
- Publication Date
- 2026-04-28
AI Technical Summary
Existing multi-conductor non-invasive current measurement technology suffers from problems such as poor measurement accuracy, low measurement efficiency, difficulty in ensuring the accuracy of measurement results, and susceptibility to environmental interference.
A magnetic field sensor array with low noise sensors surrounds a multi-conductor cable to detect magnetic field signals, establish the relationship between magnetic field and current, perform noise reduction processing, verify the accuracy of the signal by reverse adjustment of the magnetic field sensor array, and deduce the position of the conductor and the magnitude of the current through an inversion algorithm.
It improves measurement accuracy and reliability, reduces the impact of environmental interference, is suitable for complex industrial environments, ensures the stability and accuracy of measurement results, and supports the stable operation and fault diagnosis of power systems.
Smart Images
Figure CN121933786A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electric power industry technology, and in particular to a multi-conductor non-invasive current measurement method, system, device and storage medium based on a low-noise sensor. Background Technology
[0002] Non-invasive current measurement methods have significant advantages such as non-contact operation, high isolation, and strong environmental adaptability, and have been widely used in the field of current measurement technology. Non-invasive current measurement methods are mainly divided into: current transformer and Rogowski coil measurement methods based on Faraday's law of electromagnetic induction, and magnetic field measurement methods based on Ampere's law.
[0003] In multi-conductor current measurement, a single sensor cannot measure the current in multiple phases; multiple sensors must be arranged in an array. However, current transformers and Rogowski coils are bulky, making them unsuitable for array configurations. Therefore, most measurements employ a magnetic field measurement method based on Ampere's law. This involves using an array of magnetic field sensors to acquire the magnetic field around the cable under test, and then reconstructing the current information from the magnetic field signal based on the established relationship between the magnetic field and the current. However, current non-invasive measurement methods suffer from poor accuracy and low efficiency, and the accuracy of the measurement results is difficult to guarantee. Consequently, non-invasive current detection for multi-core cables is not widely adopted. Summary of the Invention
[0004] In view of the above-mentioned problems, the present invention provides a multi-conductor non-invasive current measurement method, system, device and storage medium based on a low-noise sensor.
[0005] Therefore, the technical problem solved by the present invention is the problem of poor measurement accuracy, low measurement efficiency, difficulty in ensuring the accuracy of measurement results, and susceptibility to environmental interference in existing multi-conductor non-invasive current measurement technology.
[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a multi-conductor non-invasive current measurement method based on a low-noise sensor, comprising: A magnetic field sensor array is used to surround a multi-conductor cable to detect the magnetic field signal around the multi-conductor cable and establish the relationship between the magnetic field and the current. Based on the detected magnetic field signal, according to the relationship between magnetic field and current, it is determined whether the signal is in a reasonable range and noise reduction is performed to obtain the noise-reduced magnetic field signal. Based on the noise-reduced signal, the accuracy of the magnetic field signal measurement results is verified by adjusting the magnetic field sensor array in reverse. The magnetic field values at each magnetic field sensor of the qualified magnetic field sensor array are used as the actual magnetic field values at each magnetic field sensor of the magnetic field sensor array. The position and current magnitude of each conductor in the multi-conductor cable are derived through the inversion algorithm.
[0007] As a preferred embodiment of a multi-conductor non-invasive current measurement method based on low-noise sensors, wherein: The process of using a magnetic field sensor array to surround a multi-conductor cable, detecting the magnetic field signal around the multi-conductor cable, and establishing the relationship between the magnetic field and the current includes: Construct a magnetic field sensor array surrounding the multi-conductor cable under test, the array consisting of multiple sensors evenly distributed along the circumference; Collect the magnetic field signal generated by the multi-conductor cable at the spatial location of the magnetic field sensor array during operation; Based on electromagnetic field theory, a deterministic physical relationship model is constructed between the current of all conductors under test in a multi-conductor cable and the composite magnetic field signal measured by each sensor in the magnetic field sensor array. The magnetic field signal at each sensor is characterized as a function of the current of all conductors under test and their spatial positions.
[0008] As a preferred embodiment of a multi-conductor non-invasive current measurement method based on low-noise sensors, wherein: The process involves determining whether the detected magnetic field signal is within a reasonable range and performing noise reduction based on the relationship between magnetic field and current, resulting in a denoised magnetic field signal. Acquire the raw magnetic field signal collected by the magnetic field sensor array and the reference signal with the same frequency as the current to be measured; The original magnetic field signal is preprocessed, and the preprocessing includes at least amplification and frequency band selection; Using a reference signal, the preprocessed magnetic field signal is subjected to phase-sensitive synchronous detection processing, and the signal is converted to baseband. The signal after synchronous detection is low-pass filtered to remove high-frequency noise and harmonic components, thereby extracting the effective amplitude information of the magnetic field signal synchronized with the reference signal and obtaining the noise-reduced magnetic field signal.
[0009] As a preferred embodiment of a multi-conductor non-invasive current measurement method based on low-noise sensors, wherein: The process of verifying the accuracy of the magnetic field signal measurement results by reverse adjustment of the magnetic field sensor array based on the noise-reduced signal includes: The noise-reduced magnetic field signals measured by each magnetic field sensor under the initial array configuration are obtained as the first set of magnetic field measurement values; The measurement state of the magnetic field sensor array is controlled and reversed, and the magnetic field signals measured by each magnetic field sensor are acquired again after the adjustment as the second set of magnetic field measurement values. By comparing and analyzing the differences between the first group of magnetic field measurements and the second group of magnetic field measurements, an error assessment index characterizing the consistency of this measurement was calculated.
[0010] As a preferred embodiment of a multi-conductor non-invasive current measurement method based on low-noise sensors, wherein: The method of verifying the accuracy of the magnetic field signal measurement results by reverse adjustment of the magnetic field sensor array based on the noise-reduced signal also includes: Compare the error assessment index with the preset measurement accuracy threshold; If the error assessment index does not meet the preset measurement accuracy threshold, the measurement is determined to be abnormal, triggering a re-measurement and verification process. If the error assessment index meets the preset measurement accuracy threshold, the first set of magnetic field measurement values is determined to be valid and accurate magnetic field data.
[0011] As a preferred embodiment of a multi-conductor non-invasive current measurement method based on low-noise sensors, wherein: The step of using the magnetic field values at each of the qualified magnetic field sensor arrays as the actual magnetic field values at each of the magnetic field sensor arrays, and deriving the position and current magnitude of each conductor in the multi-conductor cable through an inversion algorithm includes: The magnetic field measurement values that have passed inspection and correspond to each sensor in the magnetic field sensor array are established as the actual magnetic field values. Based on the initial position and current parameters of the conductor to be inverted, and according to the physical relationship model between magnetic field and current, the theoretical magnetic field value at each sensor position under the initial parameters is calculated.
[0012] The beneficial effects of this preferred technical solution are as follows: the verified measured values are established as actual values, ensuring the validity of the input data for the inversion algorithm; by setting initial parameters for the inversion problem and calculating the theoretical magnetic field value, the complex inverse problem is transformed into an optimization problem that can be solved by iterative algorithms, thus finding a calculation starting point for subsequent optimization.
[0013] As a preferred embodiment of a multi-conductor non-invasive current measurement method based on low-noise sensors, wherein: The step of using the magnetic field values at each of the qualified magnetic field sensor arrays as the actual magnetic field values at each of the magnetic field sensor arrays, and deriving the position and current magnitude of each conductor in the multi-conductor cable through an inversion algorithm, also includes: Establish an objective function that measures the overall difference between the actual and theoretical magnetic field values. The position and current parameters of the conductor are automatically adjusted through an iterative algorithm to minimize the objective function until the overall difference is less than or equal to a preset threshold error. When the preset threshold error is met, the conductor position parameters and current parameters obtained in the current iteration are used as the spatial position and current magnitude of each conductor inside the multi-conductor cable in the final inversion.
[0014] The beneficial effects of this preferred technical solution are as follows: by establishing an objective function and an iterative optimization algorithm, the estimated values of conductor position and current can be automatically and gradually adjusted, so that the theoretically calculated magnetic field continuously approaches the actual measured magnetic field; the process automatically converges under physical constraints, and finally simultaneously and accurately solves the unknown positions and current magnitudes of multiple conductors, realizing a non-intrusive, high-precision inversion from the external magnetic field to the internal state.
[0015] Secondly, the present invention provides a multi-conductor non-invasive current measurement system based on a low-noise sensor, comprising: The magnetic field signal detection and relationship modeling module is used to use a magnetic field sensor array to surround a multi-conductor cable, detect the magnetic field signal around the multi-conductor cable, and establish the relationship between the magnetic field and the current. The magnetic field signal rationality judgment and noise reduction module is used to determine whether the detected magnetic field signal is within a reasonable range and to perform noise reduction based on the relationship between magnetic field and current, so as to obtain the noise-reduced magnetic field signal. The magnetic field measurement result accuracy verification module is used to verify the accuracy of the magnetic field signal measurement results by reverse adjustment of the magnetic field sensor array based on the noise-reduced signal. The conductor position and current magnitude inversion module is used to take the magnetic field values at each magnetic field sensor of the qualified magnetic field sensor array as the actual magnetic field values at each magnetic field sensor of the magnetic field sensor array, and deduce the position and current magnitude of each conductor in the multi-conductor cable through the inversion algorithm.
[0016] Thirdly, the present invention provides a computer device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, which, when executed by the processor, implement the steps of a multi-conductor non-invasive current measurement method based on a low-noise sensor.
[0017] Fourthly, the present invention provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the steps of a multi-conductor non-invasive current measurement method based on a low-noise sensor.
[0018] The beneficial effects of this invention are as follows: The addition of multiple layers of magnetic shielding to the magnetic field sensor array effectively reduces the impact of environmental interference on the measurement, making the measurement results more stable and reliable, and also suitable for complex industrial environments; the introduction of a lock-in amplifier circuit improves the signal-to-noise ratio of the sensing signal and enhances the detection capability of weak signals, thereby improving measurement accuracy and enabling more accurate acquisition of the magnetic field signal around multi-conductor cables; the reverse adjustment of the magnetic field sensor array verifies the measurement accuracy, ensuring the reliability of the measurement results, avoiding inaccurate results due to errors, improving measurement efficiency, and providing strong support for the stable operation and fault diagnosis of power systems. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is an overall flowchart of a multi-conductor non-invasive current measurement method based on a low-noise sensor provided by the present invention.
[0021] Figure 2 This is a schematic diagram of the relative positions of the magnetic field sensor and cable in a multi-conductor non-invasive current measurement method based on a low-noise sensor provided by the present invention.
[0022] Figure 3 This is a schematic diagram of the magnetic shielding structure of a multi-conductor non-invasive current measurement method based on a low-noise sensor provided by the present invention.
[0023] Figure 4 This is a schematic diagram of a lock-in amplifier circuit for a multi-conductor non-invasive current measurement method based on a low-noise sensor provided by the present invention. Detailed Implementation
[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0025] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a multi-conductor non-invasive current measurement method based on a low-noise sensor, comprising: S1: Use a magnetic field sensor array to surround the multi-conductor cable, detect the magnetic field signal around the multi-conductor cable, and establish the relationship between the magnetic field and the current; S2: Based on the detected magnetic field signal, according to the relationship between magnetic field and current, determine whether the signal is in a reasonable range and perform noise reduction to obtain the noise-reduced magnetic field signal; S3: Based on the noise-reduced signal, the accuracy of the magnetic field signal measurement results is verified by adjusting the magnetic field sensor array in reverse. S4: The magnetic field values at each magnetic field sensor of the qualified magnetic field sensor array are used as the actual magnetic field values at each magnetic field sensor of the magnetic field sensor array. The position and current magnitude of each conductor in the multi-conductor cable are derived through the inversion algorithm.
[0026] It should be noted that through steps S1-S4, a complete scheme for magnetic field detection and conductor information derivation of multi-conductor cables was realized. It comprehensively utilizes technologies such as magnetic field detection, signal processing, verification and correction, and inversion calculation, which effectively reduces measurement errors and improves the accuracy and reliability of measurements. It provides accurate data support and scientific analysis methods for practical applications such as operation monitoring and fault diagnosis of multi-conductor cables, and helps to ensure the safe and stable operation of the power system.
[0027] Example 2, refer to Figures 1-4 As one embodiment of the present invention, based on the previous embodiment, a multi-conductor non-invasive current measurement method based on a low-noise sensor is provided, comprising: In this embodiment, step S1 above involves using a magnetic field sensor array to surround a multi-conductor cable, detecting the magnetic field signal around the multi-conductor cable, and establishing the relationship between the magnetic field and the current, including: like Figure 2 As shown, a magnetic field sensor array surrounds a multi-conductor cable, with equal distances between each magnetic field sensor in the array. By using the magnetic field sensor array around the multi-conductor cable, the magnetic field signal around the cable is detected, and the relationship between the magnetic field and the current is established according to the Biot-Savart law.
[0028] Specifically, taking the geometric center of the magnetic field sensor array as the origin, and taking the first magnetic field sensor as... The line connecting the origin and the x-axis is used as the x-axis. A, B, and C are the three phase conductors inside the three-core cable, with coordinates as follows: , , The currents passing through the conductors are respectively , , Phase conductor A to , The distance is , O is the cable center, and R is the cable radius. , … For magnetic field sensors, the angle between the lines connecting two adjacent magnetic field sensors to the center of the cable is... Then the coordinates of the m-th magnetic field sensor are According to the Biot-Savart law, the current at the m-th magnetic field sensor is... The generated magnetic field along the tangential direction of the cable cross section , represented as: in, The permeability of free space, The subscript m indicates the m-th magnetic field sensor, and a indicates the phase current. The generated magnetic field Indicates the tangential direction along the cable cross-section.
[0029] The m-th magnetic field sensor is supplied with current. , The magnetic field generated along the tangential direction of the cable is: Where b represents the phase current The generated magnetic field, c represents the magnetic field generated by the phase current. The generated magnetic field.
[0030] The magnetic induction intensity along the tangential direction of the cable cross-section generated by the three phase currents of the m-th magnetic field sensor is: Furthermore, such as Figure 3 As shown, a multi-layer shielding device is added to the outside of the magnetic field sensor array. The multi-layer shielding device includes: a cylindrical shielding body, a multi-layer composite shielding layer, and end shielding caps. The inner cavity of the cylindrical shielding body extends along the axial direction to form a shielding space for accommodating the magnetic field sensor. The multi-layer composite shielding layer covers the outer wall of the cylindrical shielding body and includes two magnetic flux guiding layers made of high permeability ferromagnetic material. The end shielding caps are detachably connected to both ends of the cylindrical shielding body to form a closed magnetic circuit structure.
[0031] In another possible implementation, when establishing a magnetic field sensor array, multiple Hall effect sensors can be arranged in a ring at equal intervals on a rigid insulating ring frame, with the sensing surface of each sensor perpendicular to the radial direction of the cable to sense the tangential magnetic field component, and synchronously sampled through a multi-channel data acquisition card.
[0032] In another possible implementation, when building a magnetic field sensor array, a giant magnetoresistive sensor chip can be mounted on a flexible circuit board, and the circuit board can be wrapped around the outer insulation layer of the cable to form a closed measurement loop. The flexible design allows it to adapt to cables of different diameters.
[0033] In another possible implementation, a deterministic physical relationship model can be established by combining the principle of the method of images: the image current effect caused by the metal shielding layer of the cable or the nearby ground loop is taken into account in the mathematical model, thereby modifying the expression of the Biot-Savart law to more accurately describe the magnetic field distribution in complex environments.
[0034] In another possible implementation, a deterministic physical relationship model can be established by pre-creating a multidimensional lookup table containing the possible locations of conductors and the range of currents: the model calculation is transformed into efficient table lookup and interpolation operations to achieve fast positive magnetic field calculation in embedded systems.
[0035] In this embodiment, in step S2 above, based on the detected magnetic field signal, according to the relationship between magnetic field and current, it is determined whether the signal is within a reasonable range and noise reduction is performed to obtain the noise-reduced magnetic field signal, including: Noise reduction of the magnetic field signal is achieved by using a lock-in amplifier circuit; such as... Figure 4 As shown, the lock-in amplifier circuit includes: amplifier 1, amplifier 2, amplifier 3, bandpass filter, phase-sensitive detector, low-pass filter, shaper, and phase shifter; wherein, the input terminal of amplifier 1 is connected to the input signal, the output terminal of amplifier 1 is connected to the input terminal of the bandpass filter, the output terminal of the bandpass filter is connected to the input terminal of amplifier 2, and the output terminal of amplifier 2 is connected to the input terminal of the phase-sensitive detector; the input terminal of the shaper is connected to the reference signal, the output terminal of the shaper is connected to the input terminal of the phase shifter, and the output terminal of the phase shifter is connected to the input terminal of the phase-sensitive detector; the output terminal of the phase-sensitive detector is connected to the input terminal of the low-pass filter, the output terminal of the low-pass filter is connected to the input terminal of amplifier 3, and the output terminal of amplifier 3 outputs the processed signal.
[0036] In another possible implementation, phase-sensitive synchronous detection processing can also be performed by using digital lock-in amplification technology: a high-precision analog-to-digital converter is used to synchronously sample the preprocessed signal and the reference signal, and then multiplication and digital low-pass filtering operations are performed in the digital domain to accurately extract the in-phase component.
[0037] In another possible implementation, phase-sensitive synchronous detection can be performed by using a switch-type phase-sensitive detector circuit: a reference signal square wave is used to control an analog switch to periodically switch the input signal on and off, and then a low-pass filter is achieved by an integrator composed of operational amplifiers to output a DC signal.
[0038] In this embodiment, step S3 above, which verifies the accuracy of the magnetic field signal measurement results by reverse adjustment of the magnetic field sensor array based on the noise-reduced signal, includes: Based on the noise-reduced signal, the magnetic field values at each magnetic field sensor in the magnetic field sensor array are obtained. ; By reverse-adjusting the magnetic field sensor array, the adjusted magnetic field values of each magnetic field sensor are obtained. ; Set measurement accuracy threshold And calculate the relative error of the magnetic field for each magnetic field sensor. : like > If so, it is necessary to investigate the cause of the error and obtain the data again. and And recalculate ; like ≤ Then the output magnetic field values at each magnetic field sensor in the magnetic field sensor array will be displayed. .
[0039] In this embodiment, in step S4 above, the magnetic field values at each magnetic field sensor of the qualified magnetic field sensor array are used as the actual magnetic field values at each magnetic field sensor of the magnetic field sensor array. The position and current magnitude of each conductor in the multi-conductor cable are derived through the inversion algorithm, including: Based on the output As the actual magnetic field value at each magnetic field sensor in the magnetic field sensor array ; The magnetic field value is obtained based on the initial parameters obtained from the magnitude and location information of the inner conductor current in the multi-conductor cable. ; according to and The sum of squared differences is used as the error. Objective function: Where k represents the k-th magnetic field sensor, The center coordinates of the conductor, For a three-core cable, i = 1, 2, 3, r is the conductor radius, and R is the cable radius. The position of the conductor inside the cable cannot exceed the cable radius, and the current range cannot exceed the maximum current value. ; If error Less than or equal to the preset threshold error In this case, the current in the conductor is calculated based on the conductor's position information; If error Error greater than preset threshold If necessary, the conductor current magnitude and location information are optimized, and the magnetic field calculation value is re-acquired. until the error Less than the preset threshold error .
[0040] In another possible implementation, when deriving through the inversion algorithm, the standard particle swarm optimization algorithm can also be used: the position and current of each conductor are treated as a particle and searched in a multidimensional parameter space, and the root mean square error between the measured magnetic field value and the calculated value of the model is used as the fitness function to find the global optimal solution through iteration.
[0041] In another possible implementation, when deriving the algorithm through inversion, the Levenberg-Marquardt nonlinear least squares optimization algorithm can also be used. This algorithm is based on gradient information and converges quickly to the parameter solution that minimizes the objective function by iteratively adjusting the estimated values of the conductor position and current.
[0042] Example 3: The above is a schematic scheme of a multi-conductor non-invasive current measurement method based on a low-noise sensor according to this embodiment. It should be noted that the technical solution of a multi-conductor non-invasive current measurement system based on a low-noise sensor and the technical solution of the above-described multi-conductor non-invasive current measurement method based on a low-noise sensor belong to the same concept. Details not described in detail in the technical solution of the multi-conductor non-invasive current measurement system based on a low-noise sensor in this embodiment can be found in the description of the above-described technical solution of the multi-conductor non-invasive current measurement method based on a low-noise sensor.
[0043] This embodiment also provides a multi-conductor non-invasive current measurement system based on a low-noise sensor, including: The magnetic field signal detection and relationship modeling module is used to use a magnetic field sensor array to surround a multi-conductor cable, detect the magnetic field signal around the multi-conductor cable, and establish the relationship between the magnetic field and the current. The magnetic field signal rationality judgment and noise reduction module is used to determine whether the detected magnetic field signal is within a reasonable range and to perform noise reduction based on the relationship between magnetic field and current, so as to obtain the noise-reduced magnetic field signal. The magnetic field measurement result accuracy verification module is used to verify the accuracy of the magnetic field signal measurement results by reverse adjustment of the magnetic field sensor array based on the noise-reduced signal. The conductor position and current magnitude inversion module is used to take the magnetic field values at each magnetic field sensor of the qualified magnetic field sensor array as the actual magnetic field values at each magnetic field sensor of the magnetic field sensor array, and deduce the position and current magnitude of each conductor in the multi-conductor cable through the inversion algorithm.
[0044] This embodiment also provides an electronic device suitable for a multi-conductor non-invasive current measurement method based on a low-noise sensor, including: The memory and processor are used to store computer-executable instructions and execute the computer-executable instructions to realize a multi-conductor non-invasive current measurement method based on a low-noise sensor as proposed in the above embodiments.
[0045] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements a multi-conductor non-invasive current measurement method based on a low-noise sensor as proposed in the above embodiments.
[0046] The storage medium proposed in this embodiment belongs to the same inventive concept as the multi-conductor non-invasive current measurement method based on a low-noise sensor proposed in the above embodiment. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.
[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A multi-conductor non-invasive current measurement method based on a low-noise sensor, characterized in that, include: A magnetic field sensor array is used to surround a multi-conductor cable to detect the magnetic field signal around the multi-conductor cable and establish the relationship between the magnetic field and the current. Based on the detected magnetic field signal, according to the relationship between magnetic field and current, it is determined whether the signal is in a reasonable range and noise reduction is performed to obtain the noise-reduced magnetic field signal. Based on the noise-reduced signal, the accuracy of the magnetic field signal measurement results is verified by adjusting the magnetic field sensor array in reverse. The magnetic field values at each magnetic field sensor of the qualified magnetic field sensor array are used as the actual magnetic field values at each magnetic field sensor of the magnetic field sensor array. The position and current magnitude of each conductor in the multi-conductor cable are derived through the inversion algorithm.
2. The multi-conductor non-invasive current measurement method based on a low-noise sensor as described in claim 1, characterized in that, The process of using a magnetic field sensor array to surround a multi-conductor cable, detecting the magnetic field signal around the multi-conductor cable, and establishing the relationship between the magnetic field and the current includes: Construct a magnetic field sensor array surrounding the multi-conductor cable under test, the array consisting of multiple sensors evenly distributed along the circumference; Collect the magnetic field signal generated by the multi-conductor cable at the spatial location of the magnetic field sensor array during operation; Based on electromagnetic field theory, a deterministic physical relationship model is constructed between the current of all conductors under test in a multi-conductor cable and the composite magnetic field signal measured by each sensor in the magnetic field sensor array. The magnetic field signal at each sensor is characterized as a function of the current of all conductors under test and their spatial positions.
3. The multi-conductor non-invasive current measurement method based on a low-noise sensor as described in claim 2, characterized in that, The process involves determining whether the detected magnetic field signal is within a reasonable range and performing noise reduction based on the relationship between magnetic field and current, resulting in a denoised magnetic field signal. Acquire the raw magnetic field signal collected by the magnetic field sensor array and the reference signal with the same frequency as the current to be measured; The original magnetic field signal is preprocessed, and the preprocessing includes at least amplification and frequency band selection; Using a reference signal, the preprocessed magnetic field signal is subjected to phase-sensitive synchronous detection processing, and the signal is converted to baseband. The signal after synchronous detection is low-pass filtered to remove high-frequency noise and harmonic components, thereby extracting the effective amplitude information of the magnetic field signal synchronized with the reference signal and obtaining the noise-reduced magnetic field signal.
4. The multi-conductor non-invasive current measurement method based on a low-noise sensor as described in claim 3, characterized in that, The process of verifying the accuracy of the magnetic field signal measurement results by reverse adjustment of the magnetic field sensor array based on the noise-reduced signal includes: The noise-reduced magnetic field signals measured by each magnetic field sensor under the initial array configuration are obtained as the first set of magnetic field measurement values; The measurement state of the magnetic field sensor array is controlled and reversed, and the magnetic field signals measured by each magnetic field sensor are acquired again after the adjustment as the second set of magnetic field measurement values. By comparing and analyzing the differences between the first group of magnetic field measurements and the second group of magnetic field measurements, an error assessment index characterizing the consistency of this measurement was calculated.
5. The multi-conductor non-invasive current measurement method based on a low-noise sensor as described in claim 4, characterized in that, The method of verifying the accuracy of the magnetic field signal measurement results by reverse adjustment of the magnetic field sensor array based on the noise-reduced signal also includes: Compare the error assessment index with the preset measurement accuracy threshold; If the error assessment index does not meet the preset measurement accuracy threshold, the measurement is determined to be abnormal, triggering a re-measurement and verification process. If the error assessment index meets the preset measurement accuracy threshold, the first set of magnetic field measurement values is determined to be valid and accurate magnetic field data.
6. The multi-conductor non-invasive current measurement method based on a low-noise sensor as described in claim 5, characterized in that, The step of using the magnetic field values at each of the qualified magnetic field sensor arrays as the actual magnetic field values at each of the magnetic field sensor arrays, and deriving the position and current magnitude of each conductor in the multi-conductor cable through an inversion algorithm includes: The magnetic field measurement values that have passed inspection and correspond to each sensor in the magnetic field sensor array are established as the actual magnetic field values. Based on the initial position and current parameters of the conductor to be inverted, and according to the physical relationship model between magnetic field and current, the theoretical magnetic field value at each sensor position under the initial parameters is calculated.
7. The multi-conductor non-invasive current measurement method based on a low-noise sensor as described in claim 6, characterized in that, The step of using the magnetic field values at each of the qualified magnetic field sensor arrays as the actual magnetic field values at each of the magnetic field sensor arrays, and deriving the position and current magnitude of each conductor in the multi-conductor cable through an inversion algorithm, also includes: Establish an objective function that measures the overall difference between the actual and theoretical magnetic field values. The position and current parameters of the conductor are automatically adjusted through an iterative algorithm to minimize the objective function until the overall difference is less than or equal to a preset threshold error. When the preset threshold error is met, the conductor position parameters and current parameters obtained in the current iteration are used as the spatial position and current magnitude of each conductor inside the multi-conductor cable in the final inversion.
8. A multi-conductor non-invasive current measurement system based on a low-noise sensor, using the method described in any one of claims 1 to 7, characterized in that, include: The magnetic field signal detection and relationship modeling module is used to use a magnetic field sensor array to surround a multi-conductor cable, detect the magnetic field signal around the multi-conductor cable, and establish the relationship between the magnetic field and the current. The magnetic field signal rationality judgment and noise reduction module is used to determine whether the detected magnetic field signal is within a reasonable range and to perform noise reduction based on the relationship between magnetic field and current, so as to obtain the noise-reduced magnetic field signal. The magnetic field measurement result accuracy verification module is used to verify the accuracy of the magnetic field signal measurement results by reverse adjustment of the magnetic field sensor array based on the noise-reduced signal. The conductor position and current magnitude inversion module is used to take the magnetic field values at each magnetic field sensor of the qualified magnetic field sensor array as the actual magnetic field values at each magnetic field sensor of the magnetic field sensor array, and deduce the position and current magnitude of each conductor in the multi-conductor cable through the inversion algorithm.
9. An electronic device, characterized in that, include: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, which, when executed by the processor, implement the steps of the method according to any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, It stores computer-executable instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 7.