Circular array current measurement method based on magnetic field sensor chip

Abstract

The present application relates to a circular array current measurement method based on a magnetic field sensor chip, comprising: obtaining a plurality of measured magnetic induction intensities corresponding to the current on a three-phase conductor generated by a plurality of magnetic induction units, wherein the three-phase conductor comprises a first conductor, a second conductor and a third conductor with a phase difference; for each of the conductors, obtaining the magnetic induction intensity generated by the conductor on the sensitive axis of the magnetic induction unit according to the distance from each magnetic induction unit to the conductor and the sensitive offset angle of each magnetic induction unit relative to the conductor; obtaining the total intensity at the magnetic induction unit according to each magnetic induction intensity of each conductor; for the same magnetic induction unit, constructing an objective function according to the measured magnetic induction intensity and the total intensity; determining the current value of the three-phase conductor according to the rated parameters of each conductor and the objective function. The method provided by the present application can accurately measure the current of the three-phase conductor.

Description

Technical Field

[0001] The present application relates to the field of electric power measurement technology, and in particular to a circular ring array current measurement method, device, computer equipment, computer readable storage medium and computer program product based on a magnetic field sensor chip. Background Art

[0002] In response to the current measurement needs of three-phase conductors in power systems, the usual test method is to measure through a magnetic sensor device combined with a magnetic core. However, the use of a magnetic core will bring about problems such as spatial interference and core saturation, making the test results inaccurate. Summary of the invention

[0003] Based on this, it is necessary to provide a circular array current measurement method, device, computer equipment, computer readable storage medium and computer program product based on a magnetic field sensor chip to address the above technical problems.

[0004] In a first aspect, the present application provides a circular ring array current measurement method based on a magnetic field sensor chip, the method comprising:

[0005] Acquire a plurality of measured magnetic induction intensities generated by the current on the three-phase conductor in a plurality of magnetic induction units respectively corresponding to each other, wherein the three-phase conductor comprises a first conductor, a second conductor and a third conductor having a phase difference, and the plurality of magnetic induction units are arranged on a circumference with the center point of the three-phase conductor as the center;

[0006] For each of the conductive wires, the magnetic induction intensity generated by the conductive wire on the sensitive axis of the magnetic induction unit is obtained according to the distance from each magnetic induction unit to the conductive wire and the sensitive offset angle of each magnetic induction unit relative to the conductive wire, wherein the magnetic induction intensity of the first conductive wire, the second conductive wire, and the third conductive wire corresponding to each other are the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity respectively;

[0007] Acquire the total intensity at each of the magnetic sensing units according to the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity;

[0008] For the same magnetic sensing unit, constructing an objective function according to the measured magnetic induction intensity and the total intensity, wherein the objective function is used to characterize the deviation between the measured magnetic induction intensity and the total intensity;

[0009] The current value of the three-phase conductor is determined according to the rated parameters of each conductor and the objective function, wherein the rated parameters at least include the rated current value of each conductor.

[0010] In one embodiment, the obtaining of the magnetic induction intensity generated by the conductive wire on the sensitive axis of the magnetic sensing unit according to the distance from each magnetic sensing unit to the conductive wire and the sensitive offset angle of the magnetic sensing unit relative to the conductive wire respectively includes:

[0011] Determine the shortest distance and sensitive offset angle of each magnetic sensing unit relative to the wire; wherein the sensitive offset angle is the offset angle formed by the actual field intensity direction of the wire at each magnetic sensing unit and the sensitive axis direction;

[0012] The magnetic induction intensity is calculated according to the Biot-Savart law, the shortest distance and the sensitive offset angle.

[0013] In one embodiment, determining the shortest distance between each of the magnetic sensing units and the conductive wire comprises:

[0014] Obtaining a first radius formed by the center of the circle and each of the magnetic sensing units, a second radius formed by the center of the circle and the conductive wire, and an installation eccentric angle formed by the first radius and the second radius;

[0015] The shortest distance between each of the magnetic sensing units and the conductive wire is determined according to the first radius, the second radius, and the installation eccentricity angle.

[0016] In one embodiment, constructing an objective function according to the measured magnetic flux density and the total flux density comprises:

[0017] Obtaining a difference matrix and a transposed matrix corresponding to the difference matrix according to the measured magnetic induction intensity and the total intensity;

[0018] The objective function is obtained according to the product of the difference matrix and the transposed matrix.

[0019] In one embodiment, determining the current value of the three-phase conductor according to the rated parameters of each conductor and the objective function includes:

[0020] Obtaining a partial derivative function of the objective function, and performing linearization processing on the partial derivative function;

[0021] The target current value is obtained by iteratively processing the linearized partial derivative function based on the least square method and the rated current values ​​corresponding to the wires.

[0022] In one embodiment, the linearizing the partial derivative function comprises:

[0023] Performing Taylor series expansion processing on the partial derivative function to obtain an expansion function;

[0024] Obtaining a linear recursive function of the expansion function according to the Gauss-Newton method;

[0025] The iterative processing of the linearized partial derivative function based on the least square method and the rated current values ​​corresponding to the wires to obtain the target current value includes:

[0026] The target current value is obtained by iteratively processing the linear recursive function based on the least square method and each of the rated current values.

[0027] In a second aspect, the present application further provides a current measuring device based on a circular array of magnetic field sensor chips, the device comprising:

[0028] A measuring module, used for obtaining a plurality of measured magnetic induction intensities generated by a plurality of magnetic induction units respectively corresponding to the current on the three-phase conductor, wherein the three-phase conductor comprises a first conductor, a second conductor and a third conductor having a phase difference, and the plurality of magnetic induction units are arranged on a circumference with a center point of the three-phase conductor as the center;

[0029] A field intensity acquisition module is used to obtain, for each of the wires, the magnetic induction intensity generated by the wire on the sensitive axis of the magnetic induction unit according to the distance from each magnetic induction unit to the wire and the sensitive offset angle of each magnetic induction unit relative to the wire, wherein the magnetic induction intensity of the first wire, the second wire, and the third wire corresponding to each other are the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity respectively;

[0030] A calculation module, configured to obtain a total intensity at each of the magnetic sensing units according to the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity;

[0031] A function construction module, used for constructing an objective function according to the measured magnetic induction intensity and the total intensity for the same magnetic induction unit, wherein the objective function is used to characterize the deviation between the measured magnetic induction intensity and the total intensity;

[0032] A function processing module is used to determine the current value of the three-phase conductor according to the rated parameters of each conductor and the objective function, wherein the rated parameters at least include the rated current value of each conductor.

[0033] In a third aspect, the present application further provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of any of the above-mentioned three-phase conductor current measurement methods when executing the computer program.

[0034] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the aforementioned methods for measuring current of a three-phase conductor.

[0035] In a fifth aspect, the present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of any of the aforementioned three-phase conductor current measurement methods.

[0036] The current measurement method, device, computer equipment, storage medium and computer program product based on the circular array of magnetic field sensor chips respectively obtain the measured magnetic induction intensity and calculated total intensity of the current on the three-phase conductor corresponding to multiple magnetic induction units, construct an objective function based on the measured magnetic induction intensity and the calculated total intensity, and iterate the objective function using the least squares method based on the rated parameters of each conductor to calculate the current value of the three-phase conductor. The current flowing through the three-phase conductor can be accurately measured without using a magnetic core, further improving the accuracy and applicability of the measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a magnetic field generated by a phase a conductor at a magnetic induction unit T1 in one embodiment;

[0038] Figure 2 A schematic diagram of a magnetic field generated by a b-phase conductor at a magnetic sensing unit T1 in an embodiment;

[0039] Figure 3 A schematic diagram of a magnetic field generated by a c-phase conductor at a magnetic sensing unit T1 in one embodiment;

[0040] Figure 4 is a schematic flow chart of a current measurement method in one embodiment;

[0041] Figure 5 is a schematic flow chart of a current measurement method in another embodiment;

[0042] Figure 6 is a schematic flow chart of a current measurement method in another embodiment;

[0043] Figure 7 A schematic diagram of Biot-Savart's law in another embodiment;

[0044] Figure 8 is a schematic flow chart of a current measurement method in another embodiment;

[0045] Fig. 9 is a schematic flow chart of a current measurement method in another embodiment;

[0046] Fig.10is a structural block diagram of a current measuring device in one embodiment;

[0047] Fig.11 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0049] The present application provides a current measurement method for non-invasive installation, such as Figure 1 to Figure 3 As shown, the conductor to be measured is a three-phase conductor, and the three conductors 100 are respectively denoted as a first conductor a, a second conductor b, and a third conductor c, and the corresponding currents flowing through them are respectively denoted as I a ,I b ,I c , their phases differ by 120 degrees, and their amplitudes are usually approximately equal. The direction of the current flowing through the three-phase conductor is perpendicular to the plane where the magnetic induction unit is located, and the three-phase conductor forms an equilateral triangle, whose center coincides with the center O of the magnetic induction unit. The distance between the three-phase conductor and the center O is r. The n magnetic induction units 102 are evenly distributed on a circle with a radius of R and the center O of the three-phase conductor as the center, and are recorded as T1, T2, ...T n , the angle between the two magnetic sensing units is The sensitive axis direction of each magnetic sensing unit It is always perpendicular to the radius vector between the magnetic sensing unit and the center of the circle. Right now Take wire a as an example. For I a The sensitive axis direction at the first magnetic sensing unit T1 The magnetic field intensity generated on For I a The actual magnetic flux density direction generated at the first magnetic sensing unit T1, and The angle between them is defined as the sensitive deviation angle α a , the installation eccentric angle of the magnetic sensing unit ∠I a OT1=θ,y a is the distance from T1 to wire a.

[0050] In one embodiment, if Figure 4 As shown, the present application provides a current measurement method for a three-phase conductor based on a circular array of magnetic field sensor chips, the method comprising steps 402 to 410:

[0051] Step 402, obtaining a plurality of measured magnetic induction intensities generated by a plurality of magnetic induction units respectively corresponding to the current on the three-phase conductor, wherein the three-phase conductor includes a first conductor, a second conductor, and a third conductor with a phase difference, and the plurality of magnetic induction units are arranged on a circle with a center point of the three-phase conductor as the center.

[0052] The magnetic sensing unit may be Figure 1 The sensor chip shown in the figure, the measured magnetic induction intensity can be directly measured, and the measurement results are recorded as B i,测量(i＝1,2,…,n) , for example B 1,测量 represents the field strength measurement value at the first magnetic sensing unit T1, wherein n represents that there are n magnetic sensing units in total.

[0053] Step 404: For each of the conductive wires, the magnetic induction intensity generated by the conductive wire on the sensitive axis of the magnetic induction unit is obtained according to the distance from each magnetic induction unit to the conductive wire and the sensitive offset angle of each magnetic induction unit relative to the conductive wire, wherein the magnetic induction intensity of the first conductive wire, the second conductive wire, and the third conductive wire corresponding to each other are the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity, respectively.

[0054] The first conductor is conductor a, the second conductor is conductor b, the third conductor is conductor c, and the distance from the magnetic sensing unit to each of the conductors is y. a ,y b ,y c , the sensitive deviation angles of the magnetic sensing unit relative to the wire are respectively denoted as α a , α b , α c , according to y a ,y b ,y c and α a , α b , α c The first magnetic induction intensity B on the magnetic sensitive axis of a certain magnetic sensing unit can be obtained respectively 1a , the second magnetic flux density B 1b 、The third magnetic flux density B 1c .

[0055] Step 406: Obtain the total intensity at each of the magnetic sensing units according to the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity.

[0056] The total intensity of each magnetic sensing unit in the magnetic sensitive axis direction is recorded as B1, B2, ... B n Taking T1 as an example, the total intensity B1 is B 1a , B 1b , B 1c The sum of .

[0057] Step 408: for the same magnetic sensing unit, construct an objective function according to the measured magnetic induction intensity and the total intensity, wherein the objective function is used to characterize the deviation between the measured magnetic induction intensity and the total intensity.

[0058] The calculation process of the present application can be based on the least squares method, and it is necessary to first construct the objective function required by the least squares method. The measured magnetic induction intensity is the measured value of the magnetic field intensity, and the total intensity is the total calculated value of the magnetic field intensity on the magnetic sensitive axis. The objective function is constructed according to the measured magnetic induction intensity and the total intensity. The objective function is used to characterize the deviation between the measured value and the total calculated value of the magnetic field intensity generated by the three-phase conductor at the magnetic induction unit.

[0059] Step 410: determining the current value of the three-phase conductors according to the rated parameters of the conductors and the objective function, wherein the rated parameters at least include the rated current value of the conductors.

[0060] According to the least squares estimation theory, when the current obtained is the current of the three-phase conductor to be measured, the objective function is theoretically equal to zero. Since there are errors in the measurement of multi-sensor chips, in actual measurement, the solution that satisfies the minimum objective function is the quantity to be solved.

[0061] Among them, the rated current value is a preset initial iterative solution. In the solution process, an initial iterative solution needs to be selected for iteration. When the initial iterative solution is closer to the actual value, the convergence speed of the objective function is faster. When the objective function converges to a certain extent, the objective function reaches a minimum, that is, the deviation between the measured value and the total calculated value reaches a minimum. At this time, the corresponding solution is the unknown quantity to be solved.

[0062] In this embodiment, the total intensity is calculated by respectively obtaining the measured magnetic induction intensities corresponding to multiple magnetic induction units of the current on the three-phase conductor, a target function is constructed according to the measured magnetic induction intensities and the total intensity, and the target function is iteratively processed by the least squares method based on the rated parameters of each conductor to calculate the current value of the three-phase conductor. The current flowing through the three-phase conductor can be accurately measured without using a magnetic core, thereby further improving the accuracy and applicability of the measurement.

[0063] In one embodiment, if Figure 5 As shown, the step of obtaining the magnetic induction intensity generated by the conductive wire on the sensitive axis of the magnetic induction unit according to the distance from each magnetic induction unit to the conductive wire and the sensitive offset angle of the magnetic induction unit relative to the conductive wire respectively includes steps 502 to 504:

[0064] Step 502, determining the shortest distance and sensitive offset angle of each magnetic sensing unit relative to the conductor; wherein the sensitive offset angle is an offset angle formed by the actual field intensity direction of the conductor at each magnetic sensing unit and the sensitive axis direction.

[0065] Step 504, calculating the magnetic flux density according to the Biot-Savart law, the shortest distance, and the sensitive offset angle.

[0066] Specifically, taking T1 as an example, the shortest distance between the magnetic sensing unit and each of the wires is denoted as y a ,y b ,y c , each of the sensitive deviation angles is denoted as α a , α b , α c According to the Biot-Savart law, the field strength generated by the current of the three-phase conductor to be measured in the sensitive axial direction at each of the magnetic sensing units is related to the shortest distance from the magnetic sensing unit to each of the conductors and the sensitive offset angle. The total field strength generated by the current-carrying conductor to be measured at each of the magnetic sensing units can be calculated based on the shortest distance and the sensitive offset angle.

[0067] In this embodiment, by first determining the distance from each magnetic sensing unit to each wire and the sensitive offset angle, the magnetic induction intensity generated by each wire in the sensitive axis direction of the magnetic sensing unit can be calculated according to the Biot-Savart law.

[0068] In one embodiment, if Figure 6 As shown, the determining of the shortest distance between each magnetic sensing unit and the conductive wire includes steps 602 to 604:

[0069] Step 602: Obtain a first radius formed by the center of the circle and each of the magnetic sensing units, a second radius formed by the center of the circle and the conductive wire, and an installation eccentric angle formed by the first radius and the second radius.

[0070] Step 604: Determine the shortest distance between each of the magnetic sensing units and the conductive wire according to the first radius, the second radius, and the installation eccentricity angle.

[0071] For details, please continue to refer to Figure 1-Figure 3 , taking the magnetic sensing unit T1 as an example, the first radius is R, the second radius is r, and the installation eccentricity angle of the magnetic sensing unit T1 is represented by θ.

[0072] like Figure 7 As shown, according to the Biot-Savart law, the field strength generated by each wire at the magnetic induction unit T1 is expressed as:

[0073]

[0074] Where μ0 is the magnetic permeability of vacuum; is the current vector of the conductor under test; is the unit vector of the magnetic sensitive axis direction of the magnetic field sensing unit, that is, is the vector of the sensing unit relative to the position of the wire. When a current flows through an infinitely long straight conductor, that is, a three-phase wire and and When the planes formed are vertical, then

[0075]

[0076] In order to facilitate calculation, the calculation coefficient is recorded as According to (2), we can get:

[0077]

[0078]

[0079]

[0080] Combining (3) to (5), the first magnetic flux density B can be obtained: 1a :

[0081]

[0082] For wire b:

[0083]

[0084]

[0085]

[0086] Combining (7) to (9), the second magnetic flux density B can be obtained: 1b :

[0087]

[0088] For wire c:

[0089]

[0090]

[0091]

[0092] Combining (11) to (13), the third magnetic flux density B can be obtained: 1c :

[0093]

[0094] The theoretical total magnetic field intensity B1 along the sensitive axis of the magnetic sensing unit T1 is:

[0095]

[0096] In practical applications, we only need to solve I a ,I b ,I c The amplitude of , with the phase angle of Ia as the reference, is:

[0097]

[0098] From the geometric relationship, it can be known that the positional relationship between the i-th magnetic sensing unit and the conductor Ia can be expressed by the installation eccentricity angle of the magnetic sensing unit, where the installation eccentricity angle is According to (15)-(16), the calculated total intensity B in the direction of the magnetic sensitive axis of the i-th magnetic sensing unit can be obtained: i for:

[0099]

[0100] In this embodiment, by determining the installation eccentricity angle of each magnetic sensing unit and the shortest distance from each magnetic sensing unit to each of the wires, the purpose of calculating the total field strength in the sensitive axis direction at each magnetic sensing unit according to the Biot-Savart law is further achieved.

[0101] In one embodiment, if Figure 8 As shown, the objective function is constructed according to the measured magnetic induction intensity and the total intensity, including steps 802 to 804:

[0102] Step 802: Obtain a difference matrix and a transposed matrix corresponding to the difference matrix according to the measured magnetic flux density and the total intensity.

[0103] Step 804: Obtain the objective function according to the product of the difference matrix and the transposed matrix.

[0104] The calculation process of this application is solved based on the least squares method, and the least squares model is expressed as:

[0105] B i；测量 =B i (X)+e (18)

[0106] Where X is the unknown quantity x(I a ,I b ,I c ,θ) is a vector representation; e is a measurement error vector. According to the calculated value Bi(i＝1,2,…,n) and the measured value B i,测量(i＝1,2,…,n ) obtain the difference matrix and the transpose of the difference matrix, and construct the objective function J(x):

[0107] J(x)=[B i；测量 -B i (X)] T [B i；测量 -B i (X)] (19)

[0108] In this embodiment, by obtaining the difference matrix and the transposed matrix of the measured magnetic flux density and the calculated total intensity, the purpose of constructing the objective function according to the difference matrix and the transposed matrix is ​​achieved.

[0109] In one embodiment, if Fig. 9 As shown, the current value of the three-phase conductor is determined according to the rated parameters of each conductor and the objective function, including steps 902 to 904:

[0110] Step 902, obtaining a partial derivative function of the objective function, and performing linearization processing on the partial derivative function.

[0111] The objective function is used to characterize the deviation between the measured value and the calculated value of the magnetic field strength generated by the three-phase conductor. Theoretically, the objective function should be zero. In actual measurement, it is considered that the corresponding solution when the objective function is minimum is the unknown quantity to be solved.

[0112] The partial derivative function g(x) of the objective function can be solved by the following formula (20):

[0113]

[0114] in, is the Jacobian matrix of the measurement equation.

[0115] The linearizing the partial derivative function comprises:

[0116] The partial derivative function is subjected to Taylor series expansion processing to obtain an expansion function, and a linear recursive function of the expansion function is obtained according to the Gauss-Newton method.

[0117] Let the nonlinear function g(x) be zero and in the state phasor x k Perform Taylor series expansion at , and obtain the following expansion function:

[0118] g(x)=g(x k )+G(x k )(xx k )+…=0 (21)

[0119] Ignoring the higher-order terms in the above form, we obtain the linear recursive function of the Gauss-Newton method:

[0120] x k+1 =x k -[G(x k ) -1 ]·g(x k ) (twenty two)

[0121]

[0122] g(x k )=-DH(x k ) T [zh(x k )] (twenty four)

[0123] Where k represents the number of iterations, x k represents the solution of the kth iteration; G(x) is called the gain matrix.

[0124] [G(x k )]Δx k+1 =DH(x k ) T R -1 [zh(x k )] (25)

[0125] Where Δx k+1 =x k+1 -x k .

[0126] Step 904 , iteratively processing the linearized partial derivative function based on the least square method and the rated current values ​​corresponding to the wires to obtain the target current value.

[0127] Specifically, it includes iteratively processing the linear recursive function based on the least square method and each of the rated current values ​​to obtain the target current value.

[0128] There are 4 unknown variables to be solved x(I a ,I b ,I c ,θ), then at least 4 magnetic induction units are configured during the measurement process, and during the installation of the magnetic induction units, the current direction of the three-phase conductor is usually made approximately perpendicular to the plane where the circle formed by the magnetic induction units is located. In order to facilitate the solution, the initial iterative solution is selected as X(I 额定值 ,I 额定值 ,I 额定值 ,0), that is, the current preset initial iteration solution is the rated current, and the preset initial installation eccentricity angle is 0. 额定值is the rated current value of each conductor, and the rated current values ​​of the three conductors are equal. Based on the initial iterative solution and formulas (22) and (25), multiple iterations can be performed to obtain the solution corresponding to the minimum of the objective function J(x), where the I a ,I b ,I c That is the current value of the three-phase conductor to be measured.

[0129] In this embodiment, by linearizing the partial derivative function of the objective function and repeatedly iterating the linearized partial derivative function through the least squares method, the current value corresponding to the minimum of the objective function can be solved, thereby achieving accurate measurement of the current value of the three-phase conductor.

[0130] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0131] Based on the same inventive concept, the embodiment of the present application also provides a current measuring device for implementing the above-mentioned three-phase wire current measuring method based on a circular array of magnetic field sensor chips. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more measurement device embodiments provided below can refer to the limitations of the three-phase wire current measuring method above, and will not be repeated here.

[0132] In one embodiment, if Fig.10 As shown, the present application also provides a three-phase conductor current measurement device, the device comprising a measurement module 1002, a field strength acquisition module 1004, a calculation module 1006, a function construction module 1008, and a function processing module 1010:

[0133] The measuring module 1002 is used to obtain a plurality of measured magnetic induction intensities generated by a plurality of magnetic induction units respectively corresponding to the current on the three-phase conductor, wherein the three-phase conductor includes a first conductor, a second conductor and a third conductor with a phase difference, and the plurality of magnetic induction units are arranged on a circle with a center point of the three-phase conductor as the center.

[0134] The field intensity acquisition module 1004 is used to obtain, for each of the conductive wires, the magnetic induction intensity generated by the conductive wire on the sensitive axis of the magnetic induction unit according to the distance from each magnetic induction unit to the conductive wire and the sensitive offset angle of each magnetic induction unit relative to the conductive wire, wherein the magnetic induction intensity of the first conductive wire, the second conductive wire, and the third conductive wire corresponding to each other are the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity, respectively.

[0135] The calculation module 1006 is used to obtain the total intensity at each of the magnetic sensing units according to the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity.

[0136] The function construction module 1008 is used to construct an objective function according to the measured magnetic induction intensity and the total intensity for the same magnetic induction unit, wherein the objective function is used to characterize the deviation between the measured magnetic induction intensity and the total intensity.

[0137] The function processing module 1010 is used to determine the current value of the three-phase conductor according to the rated parameters of each conductor and the objective function, wherein the rated parameters at least include the rated current value of each conductor.

[0138] In this embodiment, the measurement module, the field strength acquisition module and the calculation module are used to obtain the measured magnetic induction intensity and the calculated total intensity of the current on the three-phase conductor corresponding to multiple magnetic induction units respectively. The function construction module constructs the target function according to the measured magnetic induction intensity and the total intensity. The function processing module uses the least squares method to iteratively process the target function based on the rated parameters of each conductor to calculate the current value of the three-phase conductor. The current flowing through the three-phase conductor can be accurately measured without using a magnetic core, thereby further improving the accuracy and applicability of the measurement.

[0139] In one embodiment, the field intensity acquisition module 1004 is used to acquire, for each of the conductive wires, the magnetic induction intensity generated by the conductive wire on the sensitive axis of the magnetic induction unit according to the distance from each magnetic induction unit to the conductive wire and the sensitive offset angle of the magnetic induction unit relative to the conductive wire, including:

[0140] Determine the shortest distance and sensitive offset angle of each magnetic sensing unit relative to the wire; wherein the sensitive offset angle is the offset angle formed by the actual field intensity direction of the wire at each magnetic sensing unit and the sensitive axis direction.

[0141] The magnetic induction intensity is calculated according to the Biot-Savart law, the shortest distance and the sensitive offset angle.

[0142] In one embodiment, the field strength acquisition module 1004 is used to determine the shortest distance between each magnetic sensing unit and the wire, and further includes:

[0143] A first radius formed by the center of the circle and each of the magnetic sensing units, a second radius formed by the center of the circle and the conductive wire, and an installation eccentric angle formed by the first radius and the second radius are obtained.

[0144] The shortest distance between each of the magnetic sensing units and the conductive wire is determined according to the first radius, the second radius, and the installation eccentricity angle.

[0145] In one embodiment, the function construction module 1008 is used to construct a target function according to the measured magnetic flux density and the total flux density, including:

[0146] A difference matrix and a transposed matrix corresponding to the difference matrix are obtained according to the measured magnetic flux density and the total intensity.

[0147] The objective function is obtained according to the product of the difference matrix and the transposed matrix.

[0148] In one embodiment, the function processing module 1010 is used to determine the current value of the three-phase conductor according to the rated parameters of each conductor and the objective function, including:

[0149] A partial derivative function of the objective function is obtained, and the partial derivative function is linearized.

[0150] The target current value is obtained by iteratively processing the linearized partial derivative function based on the least square method and the rated current values ​​corresponding to the wires.

[0151] In one embodiment, the function processing module 1010 is used to perform linearization processing on the partial derivative function, and further includes:

[0152] The partial derivative function is subjected to Taylor series expansion processing to obtain an expansion function.

[0153] A linear recursive function of the expansion function is obtained according to the Gauss-Newton method.

[0154] The function processing module 1010 is used to iteratively process the partial derivative function after the linearization process based on the least square method and the rated current values ​​corresponding to the wires to obtain the target current value, and further includes:

[0155] The target current value is obtained by iteratively processing the linear recursive function based on the least square method and each of the rated current values.

[0156] Each module in the above-mentioned three-phase conductor current measurement device based on the circular array of magnetic field sensor chips can be fully or partially implemented by software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the corresponding operations of each of the above modules.

[0157] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Fig.11 As shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a current measurement method for a three-phase conductor is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0158] Those skilled in the art will understand that Fig.11 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0159] In one of the embodiments, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of any of the above-mentioned three-phase conductor current measurement methods when executing the computer program.

[0160] In one of the embodiments, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the above-mentioned methods for measuring current of a three-phase conductor.

[0161] In one of the embodiments, the present application further provides a computer program product, including a computer program, which implements the steps of any of the above-mentioned three-phase conductor current measurement methods when executed by a processor.

[0162] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0163] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0164] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A circular ring array current measurement method based on a magnetic field sensor chip, characterized in that: The method comprises: Acquire a plurality of measured magnetic induction intensities generated by the current on the three-phase conductor in a plurality of magnetic induction units respectively corresponding to each other, wherein the three-phase conductor comprises a first conductor, a second conductor and a third conductor having a phase difference, and the plurality of magnetic induction units are arranged on a circumference with the center point of the three-phase conductor as the center; For the first wire, the second wire, and the third wire, the magnetic induction intensities generated by the first wire, the second wire, and the third wire on the sensitive axes of the magnetic induction units are obtained according to the distances from each magnetic induction unit to the first wire, the second wire, and the third wire, and the sensitive offset angles of each magnetic induction unit relative to the first wire, the second wire, and the third wire, respectively, wherein the magnetic induction intensities corresponding to the first wire, the second wire, and the third wire are the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity, respectively; Acquire the total intensity at each of the magnetic sensing units according to the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity; For the same magnetic sensing unit, constructing an objective function according to the measured magnetic induction intensity and the total intensity, wherein the objective function is used to characterize the deviation between the measured magnetic induction intensity and the total intensity; Determining the current value of the three-phase conductor according to the rated parameters of the first conductor, the second conductor, and the third conductor and the objective function, wherein the rated parameters at least include the rated current values ​​of the first conductor, the second conductor, and the third conductor; The obtaining, according to the distances from each magnetic sensing unit to the first wire, the second wire, and the third wire, and the sensitive offset angles of the magnetic sensing unit relative to the first wire, the second wire, and the third wire, respectively, the magnetic induction intensities generated by the first wire, the second wire, and the third wire on the sensitive axis of the magnetic sensing unit, respectively, includes: Determine respectively the shortest distance and the sensitive offset angle of each magnetic sensing unit relative to the first wire, the second wire, and the third wire; wherein the sensitive offset angle is the offset angle formed by the actual field intensity direction of the first wire, the second wire, and the third wire at each magnetic sensing unit and the sensitive axis direction; Calculate the magnetic induction intensity according to the Biot-Savart law, the shortest distance, and the sensitive offset angle; The respectively determining the shortest distances of each of the magnetic sensing units relative to the first conductive line, the second conductive line, and the third conductive line comprises: Obtaining a first radius formed by the center of the circle and each of the magnetic sensing units, a second radius formed respectively with the first wire, the second wire, and the third wire, and an installation eccentric angle formed by the first radius and the second radius; Determine the shortest distances of each of the magnetic sensing units relative to the first wire, the second wire, and the third wire respectively according to the first radius, the second radius, and the installation eccentricity angle; The constructing of the objective function according to the measured magnetic induction intensity and the total intensity comprises: Obtaining a difference matrix and a transposed matrix corresponding to the difference matrix according to the measured magnetic induction intensity and the total intensity; Obtaining the objective function according to the product of the difference matrix and the transposed matrix; The step of determining the current value of the three-phase conductor according to the rated parameters of the first conductor, the second conductor, and the third conductor and the objective function comprises: Obtaining a partial derivative function of the objective function, and performing linearization processing on the partial derivative function; The partial derivative function after the linearization process is iterated based on the least square method and the rated current values ​​corresponding to the first conductor, the second conductor, and the third conductor respectively to obtain the current value of the three-phase conductor.

2. The method according to claim 1, characterized in that: The linearizing the partial derivative function comprises: Performing Taylor series expansion processing on the partial derivative function to obtain an expansion function; Obtaining a linear recursive function of the expansion function according to the Gauss-Newton method; The iterative processing of the linearized partial derivative function based on the least squares method and the rated current values ​​corresponding to the first conductor, the second conductor, and the third conductor to obtain the current value of the three-phase conductor includes: The linear recursive function is iteratively processed based on the least square method and each of the rated current values ​​to obtain the current value of the three-phase conductor.

3. The method according to claim 1, characterized in that: The total intensity at each of the magnetic induction units is the sum of the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity.

4. The method according to claim 1, characterized in that: Among the n magnetic sensing units, the angle between two magnetic sensing units is 360° / n.

5. The method according to claim 1, characterized in that The phase difference between any two of the first conductive line, the second conductive line and the third conductive line is 120 degrees.

6. A circular array current measurement device based on a magnetic field sensor chip, characterized in that: The device comprises: A measuring module, used for obtaining a plurality of measured magnetic induction intensities generated by a plurality of magnetic induction units respectively corresponding to the current on the three-phase conductor, wherein the three-phase conductor comprises a first conductor, a second conductor and a third conductor having a phase difference, and the plurality of magnetic induction units are arranged on a circumference with a center point of the three-phase conductor as the center; A field intensity acquisition module is used to obtain, for the first wire, the second wire, and the third wire, the magnetic induction intensity generated by the first wire, the second wire, and the third wire on the sensitive axis of the magnetic induction unit according to the distances from each magnetic induction unit to the first wire, the second wire, and the third wire, and the sensitive offset angles of each magnetic induction unit relative to the first wire, the second wire, and the third wire, respectively, wherein the magnetic induction intensity of the first wire, the second wire, and the third wire corresponding to each other is the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity respectively; A calculation module, configured to obtain a total intensity at each of the magnetic sensing units according to the first magnetic induction intensity, the second magnetic induction intensity, and the third magnetic induction intensity; A function construction module, used for constructing an objective function according to the measured magnetic induction intensity and the total intensity for the same magnetic induction unit, wherein the objective function is used to characterize the deviation between the measured magnetic induction intensity and the total intensity; A function processing module, used to determine the current value of the three-phase conductor according to the rated parameters of the first conductor, the second conductor, and the third conductor and the objective function, wherein the rated parameters at least include the rated current values ​​of the first conductor, the second conductor, and the third conductor; The field intensity acquisition module is further used to respectively determine the shortest distance and sensitive offset angle of each magnetic sensing unit relative to the first wire, the second wire, and the third wire; wherein the sensitive offset angle is the offset angle formed by the actual field intensity direction and the sensitive axis direction of the first wire, the second wire, and the third wire at each magnetic sensing unit; and calculate the magnetic induction intensity according to the Biot-Savart law and the shortest distance and the sensitive offset angle; The field strength acquisition module is further used to acquire a first radius formed by the center of the circle and each of the magnetic sensing units, a second radius formed respectively with the first wire, the second wire, and the third wire, and an installation eccentric angle formed by the first radius and the second radius; and determine the shortest distance of each of the magnetic sensing units relative to the first wire, the second wire, and the third wire according to the first radius, the second radius, and the installation eccentric angle; The function construction module is also used to obtain a difference matrix and a transposed matrix corresponding to the difference matrix according to the measured magnetic induction intensity and the total intensity; and obtain the objective function according to the product of the difference matrix and the transposed matrix; The function processing module is also used to obtain the partial derivative function of the objective function and linearize the partial derivative function; based on the least squares method and the rated current values ​​corresponding to the first conductor, the second conductor, and the third conductor respectively, the linearized partial derivative function is iteratively processed to obtain the current value of the three-phase conductor.

7. The device according to claim 6, characterized in that The function processing module is also used to perform Taylor series expansion processing on the partial derivative function to obtain an expansion function; obtain a linear recursive function of the expansion function according to the Gauss-Newton method; and iteratively process the linear recursive function based on the least squares method and each rated current value to obtain the current value of the three-phase conductor.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

9. 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 the method according to any one of claims 1 to 5 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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