Fan-shaped magnetic flux large current measuring system and measuring method
By using an orthogonal symmetrical distribution structure of an arc-shaped iron-based amorphous magnetic core and a GMR sensor, the problems of large measurement error and high design complexity in existing current sensing technologies are solved, achieving current measurement results with high consistency and simplified installation.
Patent Information
- Application Number
- CN202511935892.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-22
- Publication Date
- 2026-03-03
AI Technical Summary
Existing current sensing technologies face systemic challenges in industrial control, smart grids, and new energy vehicles. These challenges include the risk of thermal loss in traditional shunts, the limited bandwidth of fluxgate sensors, the susceptibility of fiber optic sensors to environmental interference, the insufficient signal-to-noise ratio of Hall effect sensors, and the narrow linear range of giant magnetoresistive sensors, which leads to large measurement errors, high design complexity, and difficulty in adapting to mass production.
A closed ring structure composed of multiple arc-shaped iron-based amorphous magnetic cores is adopted. A GMR sensor is set in the air gap of the inner ring. The sensors are orthogonally symmetrically distributed. The magnetic field characteristic value is solved by calculating the gradient component and gradient tensor, the position of the conductor is calculated and the current value is reconstructed, eliminating the positioning dependence and simplifying the design.
It achieves highly consistent current measurement, simplifies design and production, expands the measurement current range, simplifies installation, reduces measurement errors, and improves the accuracy of measurement results.
Smart Images
Figure CN121595930A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of current measurement, and in particular to a sector-shaped magnetic flux large current measurement system and method. Background Technology
[0002] In the fields of industrial control, smart grids, and new energy vehicles, current sensing technology faces systemic challenges: traditional shunts pose a risk of thermal loss due to direct circuit connection; fluxgate sensors have limited bandwidth (<1kHz); fiber optic sensors are susceptible to environmental interference; and Hall effect sensors have insufficient signal-to-noise ratio. While giant magnetoresistive (GMR) sensors possess high sensitivity (3.6 mV / V / Oe) and low temperature drift characteristics, their narrow linear range (±3 Oe) requires magnetic shunt structures to attenuate the magnetic field. Existing magnetic shunt solutions require finite element simulation to determine the optimal sensor position, resulting in low design efficiency and inability to adapt to mass production lines. Furthermore, the current-carrying conductor is difficult to center precisely during actual installation, leading to eccentricity and magnetic field distortion. Single-sensor measurement errors reach 5%-10%, which are further exacerbated by temperature drift. Overcoming the dual constraints of position sensitivity and design complexity is urgently needed. Summary of the Invention
[0003] To address the shortcomings of existing technologies, this invention provides a sector-shaped magnetic flux high current measurement system and method to avoid current measurement errors caused by deviations in the position of the current-carrying conductor.
[0004] Therefore, the technical solution adopted by the present invention is as follows: A sector-shaped magnetic flux high current measurement system is provided, comprising: a closed ring formed by splicing multiple arc-shaped iron-based amorphous magnetic cores, wherein each magnetic core has a certain air gap with its adjacent magnetic core; a GMR sensor is provided in each air gap of the inner ring, and the two ends of the GMR sensor are respectively connected to two adjacent arc-shaped iron-based amorphous magnetic cores.
[0005] According to the above scheme, the number of arc-shaped iron-based amorphous magnetic cores, the number of air gaps, and the number of sensors are specifically four. The four air gaps and sensors are placed at 0°, 90°, 180°, and 270° respectively, forming an orthogonal symmetrical distribution.
[0006] According to the above scheme, the sensitive axis of the GMR sensor is placed along the tangent direction of the annulus.
[0007] A method for measuring large current in a sector-shaped magnetic flux is also provided, the method realizing the current measurement of the sector-shaped magnetic flux large current measurement system according to any one of the claims, the method comprising: The wire is placed at the center of the circular ring of the sector flux large current measurement system, and the power output terminals are connected at both ends to generate current. The magnetic field measurement value is collected by the sensor installed in the air gap, and the gradient component and gradient tensor are calculated based on the magnetic field measurement value. The magnetic field eigenvalues are obtained by solving the gradient components and gradient tensor, and the position of the conductor is calculated based on the magnetic field eigenvalues. The measured current value is reconstructed based on the position of the conductor to obtain the actual current value.
[0008] According to the above scheme, the gradient component calculated based on the magnetic field measurement value is specifically expressed as follows: , in, and , and , and , and These are the magnetic field measurements from the four sensors; R is the radius of the closed ring formed by splicing together multiple arc-shaped iron-based amorphous magnetic cores.
[0009] According to the above scheme, the magnetic field eigenvalues obtained by solving based on the gradient components and gradient tensor are specifically expressed as follows: , Where G represents the gradient tensor, Let G represent the trace of matrix G.
[0010] According to the above scheme, the specific representation of calculating the conductor position based on the magnetic field characteristic value is as follows:
[0011] Where x and y represent the horizontal and vertical coordinates of the conductor, respectively, r represents the nominal radius, and v x和 v y This represents the eigenvector corresponding to the eigenvalue of the magnetic field.
[0012] According to the above scheme, the actual current value is calculated by multiplying the measured current value by the ratio of the nominal radius to the actual distance.
[0013] According to the above scheme, the actual distance is calculated based on the nominal radius and the offset position of the conductor.
[0014] A computer storage medium is also provided, which stores a computer program that can be executed by a processor, the computer program performing the sector flux large current measurement method described above.
[0015] A computer device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described sector flux large current measurement method.
[0016] The beneficial effects of this invention are as follows: This invention uses a four-air-gap fan-shaped magnetic ring structure formed by four arc-shaped iron-based amorphous magnetic cores for current detection, which minimizes the magnetic field gradient at the air gap, naturally forming the optimal sensor position, eliminating positioning dependence, and eliminating the need for finite element simulation. Through this structure, magnetic field measurement is performed, and the offset position of the current conductor is calculated, thereby reconstructing the current and completing the actual current measurement. It has the advantages of simple design and production, high consistency of measurement results, large measurement current range, and simple measurement installation and implementation. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the system structure of the sector-shaped magnetic flux large current measurement system according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of the method for measuring large current of sector magnetic flux according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the calculation of the conductor offset position according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the sensor IU characteristic curve before current reconstruction in an embodiment of the present invention; Figure 5 This is a schematic diagram of the sensor IU characteristic curve after current reconstruction according to an embodiment of the present invention.
[0018] In the figure: 100 - GMR sensor; 200 - arc-shaped iron-based amorphous magnetic core. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0020] To address the problems of low accuracy and high design complexity in current measurement using current sensing technology in existing technologies, this invention provides a sector-shaped magnetic flux large current measurement system, such as... Figure 1 As shown, the measurement system includes: A closed ring is formed by splicing multiple arc-shaped iron-based amorphous magnetic cores, with each core having a certain air gap with its adjacent cores; GMR sensors are installed in each air gap of the inner ring, and the two ends of the GMR sensors are respectively connected to two adjacent arc-shaped iron-based amorphous magnetic cores.
[0021] Specifically, the measurement system in this embodiment consists of four arc-shaped iron-based amorphous magnetic cores spliced into a closed ring. The saturation magnetic flux density of the arc-shaped iron-based amorphous magnetic cores is 0.65T, and the coercivity is less than 4A / m. A 1mm air gap is set between adjacent magnetic cores, and the air gap positions are strictly orthogonally distributed at 0°, 90°, 180°, and 270°. This geometric structure eliminates the dependence on the minimum magnetic field gradient at the air gap for positioning, naturally forming the optimal sensor position and eliminating the need for finite element simulation.
[0022] In addition, this embodiment uses four GMR sensors. The four GMR sensors (SAS030-1) are embedded in the center of the air gap, forming an orthogonal symmetrical distribution consistent with the air gap. Their sensitive axes are along the tangent direction of the magnetic ring, forming a spatially symmetrical detection array. During measurement, the outputs of the four sensors constitute a vector group {B} = [B1, B2, B3, B4], providing a data basis for eccentricity detection.
[0023] In addition, this invention also provides a method for measuring large currents in a sector-shaped magnetic flux, used for current measurement in the sector-shaped magnetic flux large current measurement system described in this invention, such as... Figure 2 As shown, the method mainly includes: S1. Place the wire at the center of the circular ring of the sector magnetic flux high current measurement system, and connect the power output terminals at both ends to generate current. Collect the magnetic field measurement value through the sensor installed in the air gap, and calculate the gradient component and gradient tensor based on the magnetic field measurement value.
[0024] S2. Obtain the magnetic field eigenvalues by solving for the gradient components and gradient tensor, and calculate the position of the conductor based on the magnetic field eigenvalues.
[0025] S3. Reconstruct the measured current value based on the position of the conductor to obtain the actual current value.
[0026] Among them, the magnetic field measurements were obtained using four sensors. The gradient components are calculated using the central difference method:
[0027]
[0028] in, and , and , and , and These are the magnetic field measurements from the four sensors; R is the radius of the closed ring formed by splicing together multiple arc-shaped iron-based amorphous magnetic cores.
[0029] Obtain the gradient tensor:
[0030] in, , , and They are respectively , , and .
[0031] Construct the characteristic equation of the magnetic field based on the gradient tensor:
[0032] Solving the characteristic equation of this magnetic field yields the characteristic solution:
[0033] Where G represents the gradient tensor, Let G represent the trace of matrix G.
[0034] For the magnetic field of the conductor in this embodiment, the eigenvalues satisfy... (No divergent field).
[0035] Specifically, such as Figure 3 As shown, the offset position of the conductor from the center point is calculated based on the characteristic value: Among them, the position of the conductor With the main feature vector The relationship is:
[0036] Where μ0 represents the relative permeability of air.
[0037] Simultaneously, current dependence is eliminated by utilizing magnetic field amplitude constraints: defining the position vector. ,but:
[0038] in It is the geometric mean of the magnetic field amplitudes of the four sensors. Solving simultaneously, we get:
[0039] Specifically, based on the Biot-Savart law, the measured current is reconstructed to obtain the actual current. With measuring current satisfy:
[0040]
[0041] Where r is the nominal radius (4.5 mm). This represents the actual distance.
[0042] In addition, embodiments of the present invention also provide a computer-readable storage medium, such as flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, server, App application store, etc., which stores a computer program, and the program implements the corresponding function when executed by a processor. In this embodiment, the computer-readable storage medium, when executed by a processor, implements the sector magnetic flux large current measurement method of the method embodiment.
[0043] In addition, embodiments of the present invention also provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described sector flux large current measurement method.
[0044] To verify the effectiveness of the current measurement method in this embodiment of the invention, system tests were conducted within a current range of ±100A to evaluate the measurement linearity and accuracy, and to verify the performance of the adaptive position compensation algorithm based on the magnetic field gradient tensor invariant.
[0045] First, place the wire at the center of the circle. Connect the power output of the bipolar output system to the wire, starting from 0A and increasing in 1A increments until reaching 100A. Then, decrease the current in -1A increments until reaching -100A. Next, increase the current in 0.1A increments until the current completes a loop. Record the values for each sensor using a multimeter and plot the IU curve. Use a multimeter (set to millivolt range) to test the voltage of each of the four sensors, recording the corresponding sensor output current and plotting the IU curve. The IU curve is shown below. Figure 4 .
[0046] The IU characteristic curves of each sensor before current reconstruction are as follows: Figure 4 As shown, the measurement range of each sensor is within the linear range of the four sensors at ±50A, and the IU curves of the four sensors are nearly parallel, indicating that the sensitivity of these sensors is similar. However, the figure shows that the measurement results of sensor 1 and sensor 3 are similar, the measurement results of sensor 2 and sensor 4 are similar, and the zero drift of each sensor is not exactly the same. The conductor current was reconstructed using an adaptive position compensation algorithm based on the magnetic field gradient tensor invariant on the above-collected data. The reconstructed sensor IU characteristic curves are shown below. Figure 5 .
[0047] This invention provides a sector-shaped magnetic flux high-current measurement system and method. It uses a four-air-gap sector-shaped magnetic ring structure formed by four arc-shaped iron-based amorphous magnetic cores for current detection. This minimizes the magnetic field gradient at the air gaps, naturally creating the optimal sensor location, eliminating positioning dependence, and saving the need for finite element simulation. The system measures the magnetic field and calculates the offset position of the current conductor, thereby reconstructing the current and completing the actual current measurement. It has the advantages of simple design and production, high consistency of measurement results, a large measurement current range, and simple measurement installation and implementation.
[0048] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.
[0049] The order of the steps in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.
[0050] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A sector-shaped magnetic flux high-current measurement system, characterized in that, include: A closed ring is formed by splicing multiple arc-shaped iron-based amorphous magnetic cores, with each core having a certain air gap with its adjacent cores; GMR sensors are installed in each air gap of the inner ring, and the two ends of the GMR sensors are respectively connected to two adjacent arc-shaped iron-based amorphous magnetic cores.
2. The sector-shaped magnetic flux high-current measurement system according to claim 1, characterized in that, The number of arc-shaped iron-based amorphous magnetic cores, air gaps, and sensors is specifically four. The four air gaps and sensors are placed at 0°, 90°, 180°, and 270° respectively, forming an orthogonal symmetrical distribution.
3. The sector-shaped magnetic flux high-current measurement system according to claim 1, characterized in that, The sensitive axis of the GMR sensor is positioned along the tangent of the annulus.
4. A method for measuring large current in a sector-shaped magnetic flux, characterized in that, The method implements current measurement in the sector-shaped magnetic flux high-current measurement system according to any one of the claims, the method comprising: The wire is placed at the center of the circular ring of the sector flux large current measurement system, and the power output terminals are connected at both ends to generate current. The magnetic field measurement value is collected by the sensor installed in the air gap, and the gradient component and gradient tensor are calculated based on the magnetic field measurement value. The magnetic field eigenvalues are obtained by solving the gradient components and gradient tensor, and the position of the conductor is calculated based on the magnetic field eigenvalues. The measured current value is reconstructed based on the position of the conductor to obtain the actual current value.
5. The method for measuring large current of sector magnetic flux according to claim 1, characterized in that, The gradient component, calculated based on the measured magnetic field value, is specifically expressed as follows: ， in, and , and , and , and These are the magnetic field measurements from the four sensors; R is the radius of the closed ring formed by splicing together multiple arc-shaped iron-based amorphous magnetic cores.
6. The method for measuring large current of sector magnetic flux according to claim 1, characterized in that, The magnetic field eigenvalues obtained by solving based on the gradient components and gradient tensor are specifically expressed as follows: ， Where G represents the gradient tensor, Let G represent the trace of matrix G.
7. The method for measuring large current of sector magnetic flux according to claim 1, characterized in that, The specific representation of calculating the position of the conductor based on the characteristic values of the magnetic field is as follows: Where x and y represent the horizontal and vertical coordinates of the conductor, respectively, r represents the nominal radius, and v x和 v y This represents the eigenvector corresponding to the eigenvalue of the magnetic field.
8. The method for measuring large current of sector magnetic flux according to claim 1, characterized in that, The actual current value is calculated by multiplying the measured current value by the ratio of the nominal radius to the actual distance.
9. The method for measuring large current of sector magnetic flux according to claim 1, characterized in that, The actual distance is calculated based on the nominal radius and the offset position of the conductor.
10. A computer storage medium, characterized in that, It contains a computer program that can be executed by a processor, which performs the sector magnetic flux large current measurement method according to any one of claims 4-9.