Magnetic array current sensing method, system and device considering conductor offset and medium

Abstract

The invention relates to the technical field of non-contact current sensing, and discloses a magnetic array current sensing method, system and device considering conductor offset and a medium, and the method comprises the steps: arranging a plurality of magnetic field sensing units around a current-carrying conductor, collecting magnetic field data, and converting the magnetic field data into an analog voltage signal; performing multi-channel sampling on the analog voltage signal through a multi-channel analog-digital sampler, and calculating the magnetic field intensity induced by each magnetic field sensing unit; based on the magnetic field intensity, the position and the inclination angle of the current-carrying conductor are corrected, the influence of geometric offset on a measurement result is compensated, and high-precision non-contact current measurement is realized. Under the condition that the position of the current-carrying conductor deviates or the inclination angle changes, high-accuracy measurement of the current can still be achieved, and through a non-contact measurement mode, the method has the advantages of being flexible, high in precision, high in robustness and the like. And a new method is provided for the accurate and flexible measurement of the current of the current-carrying conductor.

Description

Technical Field

[0001] The present invention relates to the technical field of contactless current sensing, and in particular to a magnetic array current sensing method, system, device and medium taking conductor deviation into account. Background Art

[0002] The magnetic array current sensor is based on advanced magnetic field sensing technology. By measuring the magnetic field at multiple measurement points in the space around the measured current and combining it with the magnetic field inverse problem solving algorithm, it can achieve accurate measurement of the measured current. It has many advantages such as non-contact, broadband, flexible point distribution, compact size, and light weight. It is expected to achieve distributed wide-area measurement of power grid current. However, when the relative position between the current-carrying conductor and the magnetic array current sensor is offset, if the traditional current measurement method based on discrete loop integration is used, a large measurement error will be generated, resulting in poor or even excessive measurement accuracy of the magnetic array current sensor.

[0003] In view of the above problems, the present invention proposes a magnetic array current sensing method and device taking conductor offset into account. The proposed magnetic array current sensing device is composed of functional modules such as a magnetic field sensor array, a multi-channel analog-digital sampler, a digital signal processing unit, and a current inversion unit. The magnetic field sensor array senses, that is, measures the magnetic field at multiple measurement points around the current-carrying conductor; the multi-channel analog-digital sampler is responsible for sampling the analog voltage signal output by the magnetic field sensor array and converting it into a digital signal; the digital signal processing unit processes the sampled digital signal to obtain the magnetic field result measured by the magnetic field sensor array, and transmits it to the current inversion unit; the current inversion unit obtains the current of the current-carrying conductor, that is, the measured current, by solving the inverse problem of the magnetic field, and determines the position and inclination angle of the current-carrying conductor at the same time. The present invention proposes a magnetic array current sensing method and device taking conductor offset into account, which has the ability to achieve high-accuracy measurement of the measured current even when the position of the current-carrying conductor is offset, and is expected to provide a new idea for the flexible and accurate measurement of the current of the current-carrying conductor. Summary of the invention

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

[0005] Therefore, the technical problem solved by the present invention is: the current measurement error caused by the relative position offset between the current-carrying conductor and the magnetic array current sensor.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a magnetic array current sensing method taking conductor offset into account, comprising:

[0007] Arrange multiple magnetic field sensing units around the current-carrying conductor to collect magnetic field data and convert them into analog voltage signals;

[0008] Perform multi-channel sampling of the analog voltage signal by a multi-channel analog-digital sampler to calculate the magnetic field intensity sensed by each magnetic field sensing unit;

[0009] Based on the magnetic field strength, the position and tilt angle of the current-carrying conductor are corrected to compensate for the influence of geometric offset on the measurement results, thus achieving high-precision non-contact current measurement.

[0010] As a preferred solution of the magnetic array current sensing method taking into account conductor offset described in the present invention, wherein: collecting magnetic field data includes arranging a plurality of magnetic field sensing units around the current-carrying conductor to form a magnetic field sensing array, and sensing the magnetic field data generated at different measuring points around the current-carrying conductor in real time;

[0011] The magnetic field data includes magnetic field intensity and magnetic field direction;

[0012] Convert the magnetic field strength into an analog voltage signal.

[0013] As a preferred solution of the magnetic array current sensing method taking into account conductor offset of the present invention, the multi-channel sampling includes using a multi-channel analog-digital sampler to simultaneously receive analog voltage signals from multiple magnetic field sensing units;

[0014] Each magnetic field sensing unit corresponds to an independent channel. The multi-channel analog-digital sampler amplifies and filters the analog voltage signals from different magnetic field sensing units and converts them into digital signals through an analog-to-digital converter.

[0015] As a preferred solution of the magnetic array current sensing method taking into account conductor offset described in the present invention, wherein: the high-precision non-contact current measurement includes, according to the Biot-Savart law, establishing a three-dimensional magnetic field model of the current-carrying conductor to describe the distribution of the magnetic field generated in the space around the current-carrying conductor;

[0016] Based on the magnetic field data and the three-dimensional magnetic field model, a nonlinear equation group is constructed to describe the relationship between the measured magnetic field data and the magnetic field value obtained by theoretical calculation;

[0017] The nonlinear equations are transformed into a nonlinear least squares problem. The objective function is to minimize the deviation between the measured magnetic field and the magnetic field calculated by the three-dimensional magnetic field model to solve the position offset, inclination angle and current of the current-carrying conductor.

[0018] As a preferred solution of the magnetic array current sensing method taking conductor offset into account described in the present invention, wherein: the high-precision non-contact current measurement further includes, in the process of solving the least squares problem, taking the position offset and the tilt angle of the current-carrying conductor as variables to be solved, obtaining the actual position and tilt angle of the current-carrying conductor in three-dimensional space through optimization calculation, and compensating for the measurement error caused by the geometric offset;

[0019] Based on the corrected geometric parameters and magnetic field distribution, the current in the current-carrying conductor is inversely calculated.

[0020] As a preferred solution of the magnetic array current sensing method taking conductor offset into account according to the present invention, the magnetic field distribution generated by the current-carrying conductor in three-dimensional space is expressed by the formula:

[0021]

[0022]

[0023]

[0024] in, represents the x-direction magnetic field component at the kth measurement point, represents the y-direction magnetic field component at the kth measurement point, represents the z-direction magnetic field component at the kth measurement point; μ0 represents the vacuum magnetic permeability, and I represents the current x flowing through the current-carrying conductor. I represents the geometric center coordinates of the current-carrying conductor in the x direction, y I represents the geometric center coordinates of the current-carrying conductor in the y direction; α represents the angle between the current-carrying conductor and the positive direction of the z axis, β represents the angle between the projection of the current-carrying conductor on the xoy plane and the positive direction of the x axis; m, n, p represent parameters related to the inclination angle of the current-carrying conductor, and their expressions are respectively m = sin (α) cos (β), n = sin (α) sin (β), p = cos (α);

[0025] Assume the position coordinates of the magnetic field sensor unit S are When the magnetic sensitivity direction is in the xoy plane, the angle between the magnetic sensitivity direction and the positive direction of the x-axis is θ k , the angle is defined as the magnetic sensitive direction angle of the k-th magnetic field sensing unit, and the formula for the magnetic field sensed by the k-th magnetic field sensing unit is expressed as:

[0026]

[0027] in, represents the magnetic field component in the × direction at the kth measurement point, represents the y-direction magnetic field component at the kth measurement point, Represents the calculated magnetic field data.

[0028] As a preferred solution of the magnetic array current sensing method taking conductor offset into account according to the present invention, the formula of the objective function is expressed as:

[0029]

[0030] in, Indicates the magnetic field value measured by the magnetic field sensing unit, represents the calculated magnetic field data;

[0031] The formula for back-calculating the current of the current-carrying conductor is expressed as:

[0032]

[0033] in, represents the average current of the current-carrying conductor obtained by inversion calculation, R represents the radius of the magnetic field sensor unit array, μ0 represents the vacuum magnetic permeability, N represents the number of sensor units in the magnetic field sensor array, Represents the average value of the magnetic field measured by the kth sensor unit.

[0034] As a preferred solution of the magnetic array current sensing method taking into account conductor offset described in the present invention, wherein: the magnetic field sensing array is composed of a plurality of magnetic field sensing units, which are arranged around the current-carrying conductor and are used to sense and measure the magnetic field strength around the conductor;

[0035] A multi-channel analog-digital sampler samples the analog voltage signal output by the magnetic field sensor array and converts it into a digital signal;

[0036] A digital signal processing unit processes the collected digital signals, calculates and obtains the magnetic field strength sensed by each magnetic field sensing unit;

[0037] The current inversion unit solves the inverse magnetic field problem and calculates the current flowing through the current-carrying conductor while determining the geometric offset and tilt angle of the conductor.

[0038] A computer device comprises: a memory and a processor; the memory stores a computer program, wherein the processor implements the steps of any one of the methods of the present invention when executing the computer program.

[0039] A computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of any one of the methods of the present invention.

[0040] Beneficial effects of the invention: The magnetic array current sensing method taking conductor offset into account provided by the invention can still achieve high-accuracy measurement of current even when the current-carrying conductor is offset or the inclination angle changes, and has the advantages of flexibility, high precision, strong robustness, etc. through non-contact measurement. A new method is provided for accurate and flexible measurement of current in current-carrying conductors. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0042] Figure 1 An overall flow chart of a magnetic array current sensing method taking conductor offset into account provided by the first embodiment of the present invention;

[0043] Figure 2 A flow chart of a magnetic array current sensing method taking conductor offset into account provided by a second embodiment of the present invention;

[0044] Figure 3 A flowchart of an algorithm for solving an inverse magnetic field problem of a magnetic array current sensing method taking conductor offset into account provided by the first embodiment of the present invention;

[0045] Figure 4 A schematic diagram of a magnetic field generated by a current-carrying conductor in the surrounding space of a magnetic array current sensing method taking conductor offset into account provided by the first embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0047] Example 1, reference Figure 1 , as one embodiment of the present invention, provides a magnetic array current sensing method taking conductor offset into account, comprising:

[0048] The present invention proposes a magnetic array current sensing method and device that takes conductor offset into account, and the core link is the current inversion unit. The current inversion unit obtains the current of the current-carrying conductor, i.e., the measured current, by calculating and solving the inverse magnetic field problem based on the magnetic field result measured by the magnetic field sensing array fed by the digital signal processing unit. The implementation process of solving the inverse magnetic field problem is as follows: Figure 3 As shown,

[0049] S1: Arrange multiple magnetic field sensing units around the current-carrying conductor to collect magnetic field data and convert them into analog voltage signals.

[0050] Collecting magnetic field data includes arranging a plurality of magnetic field sensing units around the current-carrying conductor to form a magnetic field sensing array to sense the magnetic field data generated at different measuring points around the current-carrying conductor in real time.

[0051] The magnetic field data includes magnetic field strength and magnetic field direction.

[0052] Convert the magnetic field strength into an analog voltage signal.

[0053] Furthermore, by arranging multiple magnetic field sensing units around the current-carrying conductor to form a magnetic field sensing array, the magnetic field data at different positions around the conductor can be sensed in real time. This design allows the acquisition of magnetic field information at different spatial points, thereby achieving comprehensive perception of magnetic field changes.

[0054] Furthermore, it provides magnetic field data at multiple points in space, which provides sufficient input information for subsequent calculations and ensures that the current and position changes generated by the conductor can be accurately analyzed.

[0055] S2: Perform multi-channel sampling on the analog voltage signal through a multi-channel analog-digital sampler to calculate the magnetic field intensity sensed by each magnetic field sensing unit.

[0056] Multi-channel sampling includes using a multi-channel analog-to-digital sampler to simultaneously receive analog voltage signals from multiple magnetic field sensing units.

[0057] Each magnetic field sensing unit corresponds to an independent channel. The multi-channel analog-digital sampler amplifies and filters the analog voltage signals from different magnetic field sensing units and converts them into digital signals through an analog-to-digital converter.

[0058] Furthermore, using a multi-channel analog-digital sampler to simultaneously process signals from multiple sensors can effectively improve the efficiency of data collection and ensure that the signals from each sensor are processed synchronously, reducing errors caused by time differences. At the same time, the sampler amplifies and filters the signal to ensure the quality of the collected signal.

[0059] S3: Based on the magnetic field strength, the position and tilt angle of the current-carrying conductor are corrected to compensate for the influence of geometric offset on the measurement results, thus achieving high-precision non-contact current measurement.

[0060] The magnetic field generated by the current-carrying conductor at the location of a single magnetic field sensing unit is a three-dimensional model of the magnetic field generated by the current in the space around it. Figure 4 As shown, multiple magnetic field sensing units (for the convenience of description, only one magnetic field sensing unit S is shown) are evenly arranged in a circular ring around the current-carrying conductor. The current flowing through the conductor is I, and the magnetic field generated by the current at the position of the kth magnetic field sensing unit S is B k, the expressions of the magnetic field components in the x, y, and z directions are as follows

[0061]

[0062] in, represents the x-direction magnetic field component at the kth measurement point, represents the y-direction magnetic field component at the kth measurement point, represents the z-direction magnetic field component at the kth measurement point; μ0 represents the vacuum magnetic permeability, and I represents the current x flowing through the current-carrying conductor. I represents the geometric center coordinates of the current-carrying conductor in the x direction, y I represents the geometric center coordinates of the current-carrying conductor in the y direction; α represents the angle between the current-carrying conductor and the positive direction of the z axis, β represents the angle between the projection of the current-carrying conductor on the xoy plane and the positive direction of the x axis; m, n, p represent parameters related to the inclination angle of the current-carrying conductor, and their expressions are respectively m=sin(α)cos(β), n=sin(α)sin(β), p=cos(α).

[0063] Assume the position coordinates of the magnetic field sensor unit S are When the magnetic sensitivity direction is in the xoy plane, the angle between the magnetic sensitivity direction and the positive direction of the x-axis is θ k , the angle is defined as the magnetic sensitive direction angle of the k-th magnetic field sensing unit, and the formula for the magnetic field sensed by the k-th magnetic field sensing unit is expressed as:

[0064]

[0065] in, represents the magnetic field component in the × direction at the kth measurement point, represents the y-direction magnetic field component at the kth measurement point, Represents the calculated magnetic field data.

[0066] If the magnetic sensitivity direction of the magnetic field sensing unit S is toward the negative direction of the z-axis, the expression of the magnetic field sensed by the magnetic field sensing unit is:

[0067]

[0068] Regarding the magnetic field at multiple magnetic field measurement points measured by the magnetic field sensor array, based on the measured magnetic field The principle that the magnetic field should be equal to that calculated by equation (2) or equation (3) can be used to obtain an equation whose expression is as follows:

[0069]

[0070] In equation (4), there are five unknown variables to be solved, including the current I flowing through the current-carrying conductor, the coordinates of the intersection of the current-carrying conductor and the xoy plane (x I ,y I ), the angle α between the current-carrying conductor and the positive direction of the z-axis, and the angle β between the projection of the current-carrying conductor on the xoy plane and the positive direction of the x-axis; and the position coordinates of the magnetic field sensing unit and magnetic sensitivity direction angle All of them are known quantities obtained by calibration. In order to determine the above unknown variables, at least 5 equations of the form of equation (4) need to be constructed. Therefore, the magnetic field sensor array used contains at least 5 magnetic field sensor units, so as to construct a nonlinear equation system with the number of equations equal to the number of magnetic field sensor units, and transform the above nonlinear equation system into a nonlinear least squares problem. The objective function of the problem is defined as follows

[0071]

[0072] in, is the magnetic field result calculated by formula (2) or formula (3); It is the magnetic field result actually measured by each magnetic field sensing unit.

[0073] In order to improve the efficiency and accuracy of solving the above nonlinear least squares problem, certain constraints can be imposed on the variables to be solved. Given that the current-carrying conductor is located in the circular area of ​​the magnetic field sensor array, the following constraints can be set:

[0074]

[0075] Wherein, R represents the radius of the circular magnetic field sensor array.

[0076] The angle α between the current-carrying conductor and the positive direction of the z-axis should satisfy the following constraints, namely:

[0077]

[0078] In summary, by solving the nonlinear least squares problem with equation (5) as the optimization objective function, the current of the current-carrying conductor, i.e., the measured current, can be inversely calculated, and the position and inclination angle of the current-carrying conductor can be determined at the same time. Therefore, when the position of the current-carrying conductor is offset (eccentric or tilted), the current measurement method proposed in the present invention can still measure the current of the current-carrying conductor accurately enough.

[0079] The traditional current measurement method based on discrete loop integration requires that the current-carrying conductor vertically passes through the center of the circular ring formed by the magnetic field sensor array. The expression for measuring current using this method is as follows:

[0080]

[0081] in, represents the average current of the current-carrying conductor obtained by inversion calculation, R represents the radius of the magnetic field sensor unit array, μ0 represents the vacuum magnetic permeability, N represents the number of sensor units in the magnetic field sensor array, Represents the average value of the magnetic field measured by the kth sensor unit.

[0082] Furthermore, by correcting the position and tilt angle of the current-carrying conductor, the measurement error caused by the geometric position offset of the conductor is compensated to ensure that the measurement accuracy can be maintained even if the position of the conductor in space changes. This is achieved through the three-dimensional magnetic field model and the solution of the nonlinear least squares problem.

[0083] Furthermore, when the position or tilt angle of the current-carrying conductor changes, high-precision current measurement can still be maintained, which greatly improves the robustness and practicality of the system and ensures that accurate current measurement can still be achieved in complex environments.

[0084] Embodiment 2, as Figure 2 According to one embodiment of the present invention, a magnetic array current sensing system taking conductor offset into account is provided, comprising:

[0085] A magnetic field sensing array (100) is composed of a plurality of magnetic field sensing units, arranged around a current-carrying conductor, and used for sensing and measuring the magnetic field intensity around the conductor.

[0086] The multi-channel analog-digital sampler (200) samples the analog voltage signal output by the magnetic field sensor array and converts it into a digital signal.

[0087] The digital signal processing unit (300) processes the collected digital signal, calculates and obtains the magnetic field intensity sensed by each magnetic field sensing unit.

[0088] The current inversion unit (400) solves the inverse problem of the magnetic field, calculates the current flowing through the current-carrying conductor, and simultaneously determines the geometric offset and tilt angle of the conductor.

[0089] Embodiment 3, an embodiment of the present invention, is different from the first two embodiments in that:

[0090] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0091] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0092] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0093] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0094] Example 4: In order to verify the effectiveness of the magnetic array current sensing method taking into account the conductor offset proposed in the present invention, a simulation comparison test was carried out. The current I flowing through the current-carrying conductor is set to be 10A, and 6 magnetic field sensing units are used, which are evenly distributed around the current-carrying conductor in a circular shape, and the radius of the circular shape is R = 20mm. The magnetic sensitivity direction of all magnetic field sensing units is along the tangential direction of the circular shape.

[0095] The following four current measurement cases are set to simulate different situations where the current-carrying conductor position is offset (eccentric or tilted), as follows:

[0096] Case 1: The current-carrying conductor is not eccentric or tilted, that is, the coordinates of the intersection of the current-carrying conductor and the xoy plane are (0mm, 0mm), and the tilt angles α and β are 0rad and 0rad respectively;

[0097] Case 2: The current-carrying conductor is not eccentric, but is tilted, that is, the coordinates of the intersection of the current-carrying conductor and the xoy plane are (0mm, 0mm), and the tilt angles α and β are π / 3rad and 0rad respectively;

[0098] Case 3: The current-carrying conductor is eccentric but not tilted, that is, the coordinates of the intersection of the current-carrying conductor and the xoy plane are (6mm, 8mm), and the tilt angles α and β are 0rad and 0rad respectively;

[0099] Case 4: The current-carrying conductor is eccentric and tilted, that is, the coordinates of the intersection of the current-carrying conductor and the xoy plane are assumed to be (6mm, 8mm), and the tilt angles α and β are π / 3 and 0rad respectively.

[0100] For the above four cases, according to formula (2), the magnetic field sensed or measured by each magnetic field sensing unit is calculated, and noise (noise amplitude is ±0.1% and uniformly distributed) is added to the calculated magnetic field to simulate the measured magnetic field of the magnetic field sensing unit. The measured magnetic field results are substituted into the nonlinear least squares problem with formula (5) as the objective function, and the problem is solved by calculation, thereby realizing the accurate solution of the current and determining the position and inclination angle of the current-carrying conductor. At the same time, the measured magnetic field results are substituted into the equation represented by formula (8) of the traditional current measurement method based on discrete loop integration to measure the current of the current-carrying conductor.

[0101] The relative errors of the current amplitude measured by the above two methods are shown in Table 1. In Table 1, for the four current measurement cases set, the magnetic array current sensing method taking into account the conductor offset proposed by the present invention can always achieve a high current measurement accuracy, and the relative amplitude error of the measured current is better than 2%; while the relative amplitude error of the current measured by the traditional discrete loop integration method may be very large, even as high as -11.269%, that is, when the conductor position is eccentric and tilted, the accuracy of the current measured by the traditional method will deteriorate sharply.

[0102] Table 1 Relative error of current amplitude measured by the method proposed by the present invention and the traditional method

[0103]

[0104]

[0105] Table 2 shows the position coordinates and inclination angle of the current-carrying conductor calculated by the magnetic array current sensing method taking into account the conductor offset proposed by the present invention. It can be seen from Table 2 that when the inclination angles α and β of the current-carrying conductor are set to π / 3 and 0 respectively, the calculated result of α is almost equal to its set value, and the calculated result of β is 3.14, which means that after the current-carrying conductor is rotated 180° counterclockwise around the z-axis, the current of the current-carrying conductor generates the same magnetic field distribution in the xoy plane as the original (the current-carrying conductor is not rotated), so the current of the current-carrying conductor can still be calculated more accurately; and when the inclination angles α and β of the current-carrying conductor are set to 0 and 0 respectively, the calculated result of α is close to 0, and the calculated result of β can be a random value, because when α=0, that is, the current-carrying conductor is perpendicular to the xoy plane, when β takes any value, the magnetic field distribution in the xoy plane will not change, so that the current of the current-carrying conductor can still be accurately measured.

[0106] Table 2 The coordinates and inclination angles of the current-carrying conductor calculated by the method proposed in the present invention

[0107]

[0108] It can be seen that the current measurement error of the traditional current measurement method based on discrete loop integration is very sensitive to the eccentricity and tilt of the current-carrying conductor, and the robustness of the current measurement is poor. However, the magnetic array current sensing method taking into account the conductor offset proposed in the present invention can always accurately measure the current of the current-carrying conductor under the condition of large eccentricity and tilt of the current-carrying conductor, showing excellent current measurement robustness, thereby demonstrating the correctness and rationality of the method proposed in the present invention.

[0109] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A magnetic array current sensing method taking conductor offset into account, characterized in that: include: Arrange multiple magnetic field sensing units around the current-carrying conductor to collect magnetic field data and convert them into analog voltage signals; Perform multi-channel sampling of the analog voltage signal by a multi-channel analog-digital sampler to calculate the magnetic field intensity sensed by each magnetic field sensing unit; Based on the magnetic field strength, the position and tilt angle of the current-carrying conductor are corrected to compensate for the influence of geometric offset on the measurement results, thus achieving high-precision non-contact current measurement.

2. The magnetic array current sensing method taking conductor offset into account as claimed in claim 1, characterized in that: Collecting magnetic field data includes arranging a plurality of magnetic field sensing units around the current-carrying conductor to form a magnetic field sensing array to sense magnetic field data generated at different measuring points around the current-carrying conductor in real time; The magnetic field data includes magnetic field intensity and magnetic field direction; Convert the magnetic field strength into an analog voltage signal.

3. The magnetic array current sensing method taking conductor offset into account as claimed in claim 2, characterized in that: The multi-channel sampling includes using a multi-channel analog-digital sampler to simultaneously receive analog voltage signals from multiple magnetic field sensing units; Each magnetic field sensing unit corresponds to an independent channel. The multi-channel analog-digital sampler amplifies and filters the analog voltage signals from different magnetic field sensing units and converts them into digital signals through an analog-to-digital converter.

4. The magnetic array current sensing method taking conductor offset into account as claimed in claim 3, characterized in that: The high-precision non-contact current measurement includes, according to the Biot-Savart law, establishing a three-dimensional magnetic field model of the current-carrying conductor to describe the distribution of the magnetic field generated in the space around the current-carrying conductor; Based on the magnetic field data and the three-dimensional magnetic field model, a nonlinear equation group is constructed to describe the relationship between the measured magnetic field data and the magnetic field value obtained by theoretical calculation; The nonlinear equations are transformed into a nonlinear least squares problem. The objective function is to minimize the deviation between the measured magnetic field and the magnetic field calculated by the three-dimensional magnetic field model to solve the position offset, inclination angle and current of the current-carrying conductor.

5. The magnetic array current sensing method taking conductor offset into account as claimed in claim 4, characterized in that: The high-precision non-contact current measurement also includes, in the process of solving the least squares problem, taking the position offset and the tilt angle of the current-carrying conductor as variables to be solved, obtaining the actual position and tilt angle of the current-carrying conductor in three-dimensional space through optimization calculation, and compensating for the measurement error caused by the geometric offset; Based on the corrected geometric parameters and magnetic field distribution, the current in the current-carrying conductor is inversely calculated.

6. The magnetic array current sensing method taking conductor offset into account as claimed in claim 4, characterized in that: The magnetic field distribution generated by a current-carrying conductor in three-dimensional space is expressed as: in, represents the x-direction magnetic field component at the kth measurement point, represents the y-direction magnetic field component at the kth measurement point, represents the z-direction magnetic field component at the kth measurement point; μ0 represents the vacuum magnetic permeability, and I represents the current x flowing through the current-carrying conductor. I represents the geometric center coordinates of the current-carrying conductor in the x direction, y I represents the geometric center coordinates of the current-carrying conductor in the y direction; α represents the angle between the current-carrying conductor and the positive direction of the z axis, β represents the angle between the projection of the current-carrying conductor on the xoy plane and the positive direction of the x axis; m, n, p represent parameters related to the inclination angle of the current-carrying conductor, and their expressions are respectively m = sin (α) cos (β), n = sin (α) sin (β), p = cos (α); Assume the position coordinates of the magnetic field sensor unit S are When the magnetic sensitivity direction is in the xoy plane, the angle between the magnetic sensitivity direction and the positive direction of the x-axis is θ k , the angle is defined as the magnetic sensitive direction angle of the k-th magnetic field sensing unit, and the formula for the magnetic field sensed by the k-th magnetic field sensing unit is expressed as: in, represents the magnetic field component in the × direction at the kth measurement point, represents the y-direction magnetic field component at the kth measurement point, Represents the calculated magnetic field data.

7. The magnetic array current sensing method taking conductor offset into account as claimed in claim 5, characterized in that: The objective function is expressed as follows: in, Indicates the magnetic field value measured by the magnetic field sensing unit, represents the calculated magnetic field data; The formula for back-calculating the current of the current-carrying conductor is expressed as: in, represents the average current of the current-carrying conductor obtained by inversion calculation, R represents the radius of the magnetic field sensor unit array, μ0 represents the vacuum magnetic permeability, N represents the number of sensor units in the magnetic field sensor array, Represents the average value of the magnetic field measured by the kth sensor unit.

8. A magnetic array current sensing system taking conductor offset into account using the method according to any one of claims 1 to 7, characterized in that: A magnetic field sensing array, which is composed of a plurality of magnetic field sensing units and arranged around a current-carrying conductor, is used to sense and measure the magnetic field strength around the conductor; A multi-channel analog-digital sampler samples the analog voltage signal output by the magnetic field sensor array and converts it into a digital signal; A digital signal processing unit processes the collected digital signals, calculates and obtains the magnetic field strength sensed by each magnetic field sensing unit; The current inversion unit solves the inverse magnetic field problem and calculates the current flowing through the current-carrying conductor while determining the geometric offset and tilt angle of the conductor.

9. A computer device comprising: Memory and processor; The memory stores a computer program, wherein the processor implements the steps of a magnetic array current sensing method taking conductor offset into account when executing the computer program.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a magnetic array current sensing method taking conductor offset into account are implemented.

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