Current measurement method and system based on three-axis magnetoresistance, and storage medium

Abstract

The present invention discloses a current measurement method, system, and storage medium based on a three-axis magnetoresistance, including: obtaining magnetic field vectors #imgabs0# and #imgabs1# detected by three three-axis TMR current sensors; when there is a uniform interference magnetic field, determining the amplitude range of the interference magnetic field vector #imgabs3# and the relative angle range between #imgabs5# and #imgabs6# according to #imgabs2#; based on the amplitude range and the angle range, traversing and searching for an amplitude #imgabs7# and an angle such that, in the case of eliminating the interference magnetic field #imgabs8#, the magnitudes and directions of the currents I 10 , I 20 , and I 30 satisfy preset conditions, then stop the search, and determine the current I of the wire to be measured according to the I 10 , I 20 , and I 30 . The present invention uses three TMR current sensors to accurately measure the current of the wire to be measured in a uniform interference magnetic field environment, reducing the number of TMR current sensors used for anti-interference current measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and particularly relates to a current measurement method and system based on a triaxial magnetoresistance, and a storage medium. Background Art

[0002] Accurate current sensing in a power system is the basis for power grid transient information monitoring, accident warning, condition analysis, and decision-making. With the construction of a new power system with new energy as the main body and a digital power grid, high-precision, wide-range, self-powered, and small-size requirements are put forward for current sensors. Current sensors based on the magnetoresistance effect (such as tunnel magnetoresistance (TMR) sensors) have the advantages of small size, high sensitivity, wide measurement range, etc., and have become the main development direction for intelligent current measurement in a digital power grid. Due to the complex meteorological and strong electromagnetic environment in the power grid, the measurement accuracy of TMR current sensors will be affected by interference such as sensor angle deflection, wire position offset, and electromagnetic radiation. Currently, there are methods such as spatial harmonic expansion method, high-permeability high-permeability magnetic ring method, and TMR magnetoresistance chip array to suppress interference such as position and external magnetic field.

[0003] Among them, current sensors based on TMR chips are easily affected by spatial magnetic field interference. Especially in application scenarios with a large spatial magnetic field such as bundled conductors of overhead transmission lines and distribution cabinets, the magnetic field generated by the current in adjacent wires will have a non-negligible impact on the measurement accuracy of TMR current sensors. In order to suppress external magnetic field interference, some scholars have used a magnetic field harmonic analysis method based on spatial discrete Fourier transform to calculate the external interference magnetic field, but it cannot calculate the co-frequency interference magnetic field. In addition, some scholars have proposed that using a high-permeability magnetic ring can effectively reduce the influence of spatial position on the measurement accuracy. However, when the opening air gap of the magnetic ring is too large, the external power frequency electromagnetic field is easily coupled with the measured electric quantity circuit; when the opening air gap of the magnetic ring is too small, the magnetic field in the air gap is easily saturated, resulting in too small a sensor range. The currently commonly used method is a collinear chip array composed of 4 single-axis TMR current sensors, which can effectively suppress spatial magnetic field interference, but the number of TMR chips required is large. Therefore, there is an urgent need to develop an anti-interference current measurement method to reduce the number of TMR current sensors used for anti-interference current measurement and be able to accurately measure the current of the wire to be measured in a uniformly disturbed magnetic field environment. Summary of the Invention

[0004] The purpose of the present invention is to propose a current measurement method and system based on a triaxial magnetoresistance, and a storage medium, so as to reduce the number of TMR current sensors used for anti-interference current measurement and be able to accurately measure the current of the wire to be measured in a uniformly disturbed magnetic field environment.

[0005] To achieve the above object, the present invention provides a current measurement method based on a three-axis magnetoresistance, which is implemented based on a current sensing device. The current sensing device includes a first three-axis TMR current sensor, a second three-axis TMR current sensor, and a third three-axis TMR current sensor. The magnetic sensitive directions of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are the same as the X-axis, Y-axis, and Z-axis of a preset three-dimensional coordinate system O-XYZ, respectively. The first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are located at points L, M, and N in the three-dimensional coordinate system O-XYZ, respectively.

[0006] The method includes:

[0007] Obtaining the magnetic field vectors detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and

[0008] When there is a uniform interference magnetic field, determining the amplitude range of the interference magnetic field vector based on the magnetic field vectors and the angular range of the relative angle between the interference magnetic field vector and the magnetic field vectors ; Searching through the amplitude range and the angular range to find an amplitude

[0009] and an included angle θ such that when the interference magnetic field is eliminated, the magnitudes and directions of the currents I calculated respectively according to the actual magnetic field vectors of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor meet the preset conditions, i.e., stop the search, and determine the current I of the wire to be measured according to the I 10 , I 20 and I 30 . 10 , I 20 and I 30 ;

[0010] Preferably, the amplitude range is:

[0011]

[0012] Preferably, the angular range is:

[0013] min(θ 1 , θ 2 , θ3 ) to max(θ 1 , θ 2 , θ 3 )

[0014] Where:

[0015]

[0016]

[0017]

[0018] Where:

[0019] The normal planes of are a', b', c' respectively, then k 1 , k 2 , k 3 are the direction vectors of the intersection lines of the normal planes a' and b', a' and c', b' and c' respectively.

[0020] Preferably, the currents I 10 , I 20 and I 30 satisfy a preset condition, including:

[0021] ΔI = abs(I 10 - I 20 ) + abs(I 10 - I 30 ) + abs(I 20 - I 30 ) < ε 1

[0022] Where ε 1 is a preset constant.

[0023] Preferably, the currents I 10 , I 20 and I 30 are calculated as follows:

[0024] According to Calculate the actual magnetic field vectors of the first three-axis TMR current sensor, the second three-axis TMR current sensor and the third three-axis TMR current sensor and

[0025] Obtain the three-dimensional coordinates of points L, M, N as L(x L , y L , z L ), M(x M , y M , zM ), N(x N , y N , z N );

[0026] According to the L(x L , y L , z L ), M(x M , y M , z M ), N(x N , y N , z N ), and calculate the shortest distances d from points L, M, and N to the wire L , d M , d N ;

[0027] According to the Biot - Savart law and calculate the currents I 10 , I 20 and I 30 .

[0028] Preferably, the directions of the currents I 10 , I 20 and I 30 satisfy a preset condition, including:

[0029] Δθ = abs(θ 10 - θ 20 ) + abs(θ 10 - θ 30 ) + abs(θ 20 - θ 30 ) < ε 2

[0030] where ε 2 is a preset constant, θ 10 is the direction deviation between currents I 10 and I 20 , θ 20 is the direction deviation between currents I 10 and I 30 , θ 30 is the direction deviation between currents I 20 and I 20 .

[0031] Preferably, the θ 10 , θ 20 and θ 30 are calculated in the following way:

[0032] According to Calculate the actual magnetic field vector according to the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and

[0033] According to and Calculate the included angles θ 10 、θ 20 and θ 30 respectively; wherein, The normal planes of 10 、k 20 、k 30 are a, b, and c respectively, then k

[0034] Preferably, the traversal search is performed by using the Fibonacci search method.

[0035] Preferably, the method further includes:

[0036] When there is no interfering magnetic field, calculate the current I of the wire to be measured according to the magnetic field vectors detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and Calculate the current I of the wire to be measured.

[0037] As the same inventive concept, the present invention also provides a current measurement system based on a three-axis magnetoresistance. The system is implemented based on a current sensing device, and the current sensing device includes a first three-axis TMR current sensor, a second three-axis TMR current sensor, and a third three-axis TMR current sensor. The magnetic sensitive directions of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are the same as the X-axis, Y-axis, and Z-axis of a preset three-dimensional coordinate system O-XYZ respectively. The first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are located at points L, M, and N in the three-dimensional coordinate system O-XYZ respectively;

[0038] The system includes:

[0039] A sensing signal acquisition unit, configured to acquire the magnetic field vectors detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and

[0040] A calculation unit, configured to, when there is a uniform interfering magnetic field, according to the magnetic field vector Determine the interference magnetic field vector of the amplitude range of the amplitude, and the interference magnetic field vector and the magnetic field vector the angular range of the relative angle θ therebetween;

[0041] Search unit, configured to traverse and search for an amplitude and an angle θ based on the amplitude range and the angle range, such that in the case of eliminating the interference magnetic field according to the actual magnetic field vectors of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor 10 the currents I 20 and I 30 calculated respectively 10 the sizes and directions of I 20 and I 30 meet the preset conditions, that is, stop the search, and determine the current I of the wire to be measured according to the I

[0042] As an invention under the same inventive concept, the present invention also provides a computer-readable storage medium, on which a computer program is stored, characterized in that when the computer program is executed by a processor, the steps of the above-mentioned current measurement method based on three-axis magnetoresistance are implemented.

[0043] Compared with the prior art, the present invention has at least the following advantages:

[0044] When there is a uniform interference magnetic field, the present invention determines the interference magnetic field vector according to the magnetic field vectors detected by 3 three-axis TMR current sensors of the amplitude range of the amplitude, and the interference magnetic field vector and the magnetic field vector the angular range of the relative angle θ therebetween; further, based on the amplitude range and the angle range, traverse and search for an amplitude and an angle θ, such that in the case of eliminating the interference magnetic field, according to the actual magnetic field vectors of 3 three-axis TMR current sensors the currents I 10 、I 20 and I 30 calculated respectively are substantially the same in size and direction, that is, less than a certain error range, that is, it is considered the same, and at this time, the interference magnetic field vector 10 Since theoretically the wire current I = I 20= I 30 , so the current I of the wire to be measured can be obtained according to the current I 10 、I 20 and I 30 The current I of the wire to be measured is obtained. The present invention uses 3 TMR current sensors to accurately measure the current of the wire to be measured in a uniformly disturbed magnetic field environment, reducing the number of TMR current sensors used for anti-interference current measurement.

[0045] Other features and advantages of the present invention will be described in the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0047] Figure 1 It is a schematic diagram of wire current measurement of 3 three-axis TMR current sensors without a disturbed magnetic field in an embodiment of the present invention.

[0048] Figure 2 It is a schematic diagram of wire current measurement of 3 three-axis TMR current sensors in a uniformly disturbed magnetic field in an embodiment of the present invention.

[0049] Figure 3 It is a flowchart of a current measurement method based on a three-axis magnetoresistance in an embodiment of the present invention.

[0050] Figure 4 It is a schematic diagram of Fibonacci search in an embodiment of the present invention.

[0051] Figure 5 It is a schematic diagram of spherical coordinates in an embodiment of the present invention.

[0052] Figure 6 It is a structural diagram of a current measurement system based on a three-axis magnetoresistance in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] The following will describe various exemplary embodiments, features, and aspects of the present disclosure in detail with reference to the drawings. In addition, for better illustration of the present invention, numerous specific details are given in the following detailed embodiments. Those skilled in the art should understand that the present invention can be implemented without some of these specific details. In some instances, means well-known to those skilled in the art are not described in detail to highlight the gist of the present invention.

[0054] An embodiment of the present invention provides a method for measuring current based on a three-axis magnetoresistance, which is implemented based on a current sensing device. The current sensing device includes three three-axis TMR current sensors, namely a first three-axis TMR current sensor, a second three-axis TMR current sensor, and a third three-axis TMR current sensor. The three-axis TMR current sensor can measure three directions, that is, it has three magnetic sensitive directions. The three magnetic sensitive directions of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are the same as the X-axis, Y-axis, and Z-axis of a preset three-dimensional coordinate system O-XYZ respectively. The first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are located at points L, M, and N in the three-dimensional coordinate system O-XYZ respectively. In the following vector expressions, the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are represented by subscripts L, M, and N respectively;

[0055] As Figures 1-2 shown, where Figure 1 is a schematic diagram of wire current measurement of three three-axis TMR current sensors under a non-interfering magnetic field, Figure 2 is a schematic diagram of wire current measurement of three three-axis TMR current sensors under a uniform interfering magnetic field,

[0056] Referring to Figure 3 , the method of this embodiment includes the following steps:

[0057] Step S1, obtain the magnetic field vectors and

[0058] detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor; Step S2, when there is a uniform interfering magnetic field, determine the amplitude range of the interfering magnetic field vector and the angle range of the relative angle θ between the interfering magnetic field vector and the magnetic field vector ; ;

[0059] Step S3, based on the amplitude range and the angle range, traverse and search for an amplitude and an angle θ, so that in the case of eliminating the interfering magnetic field , according to the actual magnetic field vectors of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor, the currents I 10 , I 20and I 30 The magnitude and direction of satisfy the preset conditions, then stop the search, and according to the 10 , I 20 and I 30 Determine the current I of the wire to be measured.

[0060] Specifically, when there is a uniform interference magnetic field, the method of this embodiment determines the interference magnetic field vector according to the magnetic field vectors detected by 3 three-axis TMR current sensors Determine the amplitude of the interference magnetic field vector of the amplitude range, and the relative angle θ range between the interference magnetic field vector and the magnetic field vector ; further, based on the amplitude range and the angle range, traverse and search for an amplitude and an angle θ, such that in the case of eliminating the interference magnetic field, according to the actual magnetic field vectors of 3 three-axis TMR current sensors The currents I calculated respectively 10 , I 20 and I 30 The magnitude and direction of are basically the same, that is, less than a certain error range, that is, it is considered to be the same. At this time, the interference magnetic field vector Since theoretically the wire current I = I 10 = I 20 = I 30 , so the current I of the wire to be measured can be obtained according to the currents I 10 , I 20 and I 30 Get the current I of the wire to be measured.

[0061] Based on the above description, it can be known that a uniaxial sensor can only measure one direction, such as the X-axis direction; a biaxial sensor can measure any two directions, such as the X-axis and the Z-axis; a triaxial sensor can measure three directions, namely the X-axis, the Y-axis, and the Z-axis. Since a single triaxial sensor can measure 3 directions, fewer sensors can be used to achieve current measurement, reducing the complexity of the measurement system. Compared with the method of current measurement by suppressing spatial magnetic field interference based on a collinear chip array composed of 4 uniaxial TMRs in the prior art, the method of this embodiment uses 3 TMR current sensors to accurately measure the current of the wire to be measured in a uniform interference magnetic field environment, reducing the number of TMR current sensors used for anti-interference current measurement. At the same time, the present invention can limit the search range of the magnetic field amplitude and direction, so as to quickly find the result and improve the measurement efficiency of the sensing system.

[0062] Specifically, as shown in the three-dimensional coordinate system O-XYZ in Figures 1-2 , assuming that the coordinates of 3 three-axis TMR current sensors are L(x L , yL , z L ), M(x M , y M , z M ), N(x N , y N , z N ), in the case of no magnetic field interference, the magnetic field vectors formed by the current of the wire to be measured at points L, M, and N are respectively The magnetic field vectors formed at points L, M, and N are respectively That is, the actual magnetic field vectors, and the corresponding normal planes are a, b, and c, as Figure 1 shown

[0063] Since the direction of the magnetic field vector is perpendicular to the distance from the current sensor to the wire to be measured, the position of the wire to be measured is the intersection line of the three normal planes a, b, and c. The calculation process is as follows:

[0064]

[0065] The spatial position of the wire to be measured can be calculated according to the above formula Thereby, the shortest distances d from points L, M, and N to the wire L , d M , d N can be obtained. According to the Biot - Savart law, the current can be calculated:

[0066]

[0067] If there is a uniform interference magnetic field vector in space superposed with the original magnetic field vectors at points L, M, and N to obtain the magnetic field vector The magnetic field vectors respectively correspond to the normal planes a', b', and c', as Figure 2 shown. Due to the existence of the interference magnetic field , the intersection lines of the three normal planes a', b', and c' no longer coincide, and it is impossible to accurately solve the spatial position and current magnitude of the wire to be measured. Then is not equal to . Therefore, in this embodiment, by using the magnetic field vectors detected by three three - axis TMR current sensors, and can be calculated respectively and the calculation results are compared. If they are the same or the error is less than a very small constant, it can be considered that there is no interference magnetic field Otherwise, it can be considered that there is an interference magnetic field

[0068] In the case of the existence of an interference magnetic field, as Figure 2As shown, assume that the intersection line of the normal planes a' and b' is l LM , and the intersection line of the normal planes a' and c' is l LN , and the intersection line of the normal planes b' and c' is l MN . The direction vectors of l LM , l LN , and l MN can be calculated according to the principle of Equation (1). Specifically, first find the spatial coordinates of the wire according to Formula (1), and then combine the coordinates of the known three three-axis TMR current sensors, which are L(x 1 , y 2 , z 3 ), M(x L , y L , z L ), and N(x M , y M , z M ), to calculate the direction vectors of l N , l N , and l N . LM , l LN , and l MN .

[0069] Furthermore, the included angles θ LM between l LN and l LM , θ MN between l MN and l LN , and θ 1 , θ 2 , and θ 3 are respectively:

[0070]

[0071]

[0072]

[0073] Solve for the currents I LM , I LN , and I MN corresponding to l 1 , I 2 , and I 3 according to Equation (2). Under the action of the interference magnetic field , at least one of the superimposed magnetic fields is less than the original magnetic field. Therefore, the amplitude range of the interference magnetic field is:

[0074]

[0075] Interference magnetic field The angular range of the relative angular deviation from the superimposed magnetic field is:

[0076] min(θ 1 , θ 2 , θ 3 ) ~ max(θ 1 , θ 2 , θ 3 ) (7).

[0077] Preferably, the magnitudes of the currents I 10 , I 20 and I 30 satisfy a preset condition, specifically satisfying the following formula (8):

[0078] ΔI = abs(I 10 - I 20 ) + abs(I 10 - I 30 ) + abs(I 20 - I 30 ) < ε 1 (8)

[0079] where ε 1 is a preset small constant.

[0080] Preferably, the currents I 10 , I 20 and I 30 are calculated in the following manner:[[]]

[0081] Step (1.1), calculate the actual magnetic field vectors according to the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and

[0082] Step (1.2), obtain the three-dimensional coordinates of the points L, M, and N as L(x L , y L , z L ), M(x M , y M , z M ), N(x N , y N , z N );

[0083] Step (1.3), according to the L(x L , y L , z L ), M(x M , yM , z M ), N(x N , y N , z N ), and respectively calculate the shortest distances d from points L, M, and N to the wire L , d M , d N ;

[0084] Step (1.4), according to the Biot - Savart law and respectively calculate the currents I 10 , I 20 and I 30 .

[0085] Preferably, the directions of the currents I 10 , I 20 and I 30 satisfy a preset condition, specifically satisfying the following formula (9):

[0086] Δθ = abs(θ 10 - θ 20 ) + abs(θ 10 - θ 30 ) + abs(θ 20 - θ 30 ) < ε 2 (9)

[0087] where ε 2 is a preset small constant, θ 10 is the direction deviation between the currents I 10 and I 20 , θ 20 is the direction deviation between the currents I 10 and I 30 , and θ 30 is the direction deviation between the currents I 20 and I 20 .

[0088] Preferably, the θ 10 , θ 20 and θ 30 are calculated as follows:

[0089] Step (2.1), according to calculate the actual magnetic field vectors and

[0090] Step (2.2), according to and calculate the included angles θ 10 , θ 20 and θ 30 respectively; wherein, the normal planes of 10 , k 20 , k 30 are the direction vectors of the intersection lines of the normal plane a and b, a and c, and b and c respectively.

[0091] Preferably, in this embodiment, a method of fast traversal search is also proposed, that is:

[0092] It can be known from formula (7) that and the relative angular deviation θ range, but the actual direction of is not determined. In order to improve the traversal search efficiency, the embodiment of the present invention preferably but not limitedly adopts the Fibonacci search algorithm to traverse and search for the amplitude and angle, as Figure 4 shown, based on the amplitude and angle range, the judgment value can be determined through the golden section point 0.618 and the range can be further narrowed to achieve fast search. Specifically, after determining the amplitude and direction, the actual magnetic field vectors of the first three-axis TMR current sensor, the second three-axis TMR current sensor and the third three-axis TMR current sensor can be calculated according to and Based on and According to the Biot-Savart law and calculate the currents I 10 , I 20 and I 30 respectively. It should be noted that since and are vectors with angular directions, the currents I 10 , I 20 and I 30 calculated according to the Biot-Savart law carry angular directions. Further, ΔI and Δθ can be calculated, and it can be judged whether ΔI and Δθ meet the conditions of the above formulas (8) and (9). If they are satisfied, the amplitude and angle are determined to be searched.

[0093] More specifically, as Figure 5 shown, this embodiment lists a specific method, that is: taking Establish spherical coordinates with the central axis The included angle θ between and, refer to Figure 5 It can be seen that The direction of is determined by The direction of, and θ together, where The direction of is known, so by determining and θ, the direction of can be determined The direction of. Calculated from equations (6) and (7), we get The amplitude and relative angle range are 10° ≤ θ ≤ 30°, where Oe is the unit of magnetic field strength. According to Fibonacci search, first select a certain and θ, and traverse to search for First take θ = 10° + (30° - 10°) * 0.618 = 22.36°, As the initial value, calculate ΔI and Δθ respectively. If the conditions are met, then it is the required value at this time If the conditions are not met, then further search to make If either ΔI or Δθ increases, then make Similarly, according to Fibonacci, traverse and search for and θ until the calculation results meet equations (8) and (9), and the wire current value under the non-interfering magnetic field can be calculated. Suppose Changes and is farther away from the true value, and the three lines cannot coincide more, so ΔI and Δθ increase. Suppose either ΔI or Δθ decreases, indicating that Is very close to the true value, then the traversal range of can be reduced Is 0 to 222.48°, and further take If the error increases, it means that Is farther away from the true value, so select Figure 4 The part from Mid to High in, that is, search in the range of 222.48° to 360°, and the Fibonacci search value in this range is If the error in searching the Mid to High part keeps increasing, it means that The true value is in Figure 4 The Low to Mid part of, so take

[0094] Preferably, the method further includes:

[0095] When there is no interfering magnetic field, that is, the superimposed magnetic field And And the original magnetic field are the same, and based on the magnetic field vectors detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and calculate the current I of the wire to be measured. The calculation method is as described above and will not be elaborated here.

[0096] Another embodiment of the present invention also proposes a current measurement system based on three-axis magnetoresistance. The system is implemented based on a current sensing device, which includes a first three-axis TMR current sensor, a second three-axis TMR current sensor, and a third three-axis TMR current sensor. The magnetic sensitive directions of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are the same as the X-axis, Y-axis, and Z-axis of a preset three-dimensional coordinate system O-XYZ respectively. The first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are located at points L, M, and N in the three-dimensional coordinate system O-XYZ respectively;

[0097] The functional units of the system in this embodiment can be used to execute the steps of the method described in the above embodiment. Refer to Figure 6 and the system of this embodiment includes the following functional units:

[0098] A sensing signal acquisition unit 1, configured to acquire the magnetic field vectors detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and

[0099] A calculation unit 2, configured to, when there is a uniform interference magnetic field, determine the amplitude range of the interference magnetic field vector based on the magnetic field vectors and the angular range of the relative angle θ between the interference magnetic field vector and the magnetic field vectors ; A search unit 3, configured to, based on the amplitude range and the angular range, traverse and search for an amplitude

[0100] and an angle θ such that when the interference magnetic field is eliminated, the magnitudes and directions of the currents I calculated respectively according to the actual magnetic field vectors of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor meet the preset conditions, that is, stop the search, and according to the I 10 、I 20 and I 30 the size and direction of 10 、I20 and I 30 Determine the current I of the wire to be measured.

[0101] Another embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, characterized in that when the computer program is executed by a processor, the steps of a current measurement method based on a three-axis magnetoresistance as described in the above embodiment are implemented.

[0102] Specifically, the computer-readable storage medium may include: any entity or recording medium capable of carrying the computer program instructions, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0103] Compared with the prior art, the present invention has at least the following advantages:

[0104] When there is a uniform interference magnetic field, the present invention determines the interference magnetic field vector according to the magnetic field vectors detected by 3 three-axis TMR current sensors determine the interference magnetic field vector amplitude amplitude range, and the relative angle θ range between the interference magnetic field vector and the magnetic field vector ; further, based on the amplitude range and the angle range, traverse and search for an amplitude and an included angle θ, so that in the case of eliminating the interference magnetic field, according to the actual magnetic field vectors of 3 three-axis TMR current sensors the currents I 10 、I 20 and I 30 calculated respectively are basically the same in magnitude and direction, that is, less than a certain error range, that is, it is considered the same, and at this time the interference magnetic field vector Since theoretically the wire current I = I 10 = I 20 = I 30 , so the current I of the wire to be measured can be obtained according to the currents I 10 、I 20 and I 30 . The present invention uses 3 TMR current sensors to accurately measure the current of the wire to be measured in a uniform interference magnetic field environment, reducing the number of TMR current sensors used for anti-interference current measurement.

[0105] The system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0106] It should be noted that the system described in the above embodiment corresponds to the method described in the above embodiment. Therefore, the parts not detailed in the above embodiment of the system can be obtained by referring to the content of the method described in the above embodiment. That is, the specific step content recorded in the above embodiment of the method can be understood as the functions that can be achieved by the system of this embodiment, and will not be elaborated here.

[0107] Moreover, when the current measurement system based on three-axis magnetoresistance described in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0108] Another embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the current measurement method based on three-axis magnetoresistance described in the above embodiment are implemented.

[0109] Specifically, the computer-readable storage medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0110] The various embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary technicians in the technical field to understand the disclosed embodiments.

Claims

1. A current measurement method based on a three-axis magnetoresistance, characterized in that, the method is implemented based on a current sensing device, the current sensing device includes a first three-axis TMR current sensor, a second three-axis TMR current sensor, and a third three-axis TMR current sensor, and the magnetic sensitive directions of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are the same as the X-axis, Y-axis, and Z-axis of a preset three-dimensional coordinate system O-XYZ respectively, and the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are located at points L, M, and N in the three-dimensional coordinate system O-XYZ respectively; the method includes: Obtain the magnetic field vectors detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and When there is a uniform interference magnetic field, according to the magnetic field vector determine the amplitude of the interference magnetic field vector and the amplitude range of the interference magnetic field vector as well as the angular range of the relative angle between the interference magnetic field vector and the magnetic field vector ; Traverse and search for an amplitude value based on the amplitude range and the angle range and an included angle θ such that, when the interference magnetic field is eliminated, according to the actual magnetic field vectors of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor the calculated currents I 10 , I 20 and I 30 satisfy the preset conditions in terms of magnitude and direction. Then stop the search, and determine the current I of the wire to be measured based on the I 10 , I 20 and I 30 ; The current I 10 , I 20 and I 30 have magnitudes that satisfy a preset condition, including: ΔI = abs(I 10 - I 20 ) + abs(I 10 - I 30 ) + abs(I 20 - I 30 ) < ε 1 where ε 1 is a preset constant; The current I 10 , I 20 and I 30 are calculated as follows: According to calculate the actual magnetic field vector based on the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and The three-dimensional coordinates of the points L, M, and N are obtained as L(x L , y L , z L ), M(x M , y M , z M ), and N(x N , y N , z N ); According to the L(x L , y L , z L ), M(x M , y M , z M ), N(x N , y N , z N ), and respectively calculate the shortest distances d from the three points L, M, and N to the wire L , d M , d N ; According to the Biot-Savart law and calculate the currents I 10 , I 20 and I 30 ; The current I 10 , I 20 and I 30 are in directions that satisfy a preset condition, including: Δθ = abs(θ 10 - θ 20 ) + abs(θ 10 - θ 30 ) + abs(θ 20 - θ 30 ) < ε 2 Among them, ε 2 is a preset constant, and θ 10 is the direction deviation between the current I 10 and I 20 , θ 20 is the direction deviation between the current I 10 and I 30 , θ 30 is the direction deviation between the current I 20 and I 20 ; Said θ 10 , θ 20 and θ 30 are calculated as follows: According to calculate the actual magnetic field vector based on the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and According to and calculate the included angles θ 10 , θ 20 and θ 30 respectively; among them, the normal planes are a, b, and c respectively, then k 10 , k 20 , k 30 are the direction vectors of the intersection lines of the normal planes a and b, a and c, and b and c respectively.

2. The current measurement method based on a three-axis magnetoresistance according to claim 1, characterized in that, the amplitude range is:

3. The current measurement method based on a three-axis magnetoresistance according to claim 1, characterized in that, the angle range is: min(θ 1 ,θ 2 ,θ 3 )~max(θ 1 ,θ 2 ,θ 3 ) wherein: wherein: If the normal planes are a', b', and c' respectively, then k 1 , k 2 , k 3 are the direction vectors of the intersection lines of the normal planes a' and b', a' and c', and b' and c' respectively.

4. The current measurement method based on a three-axis magnetoresistance according to claim 1, characterized in that, the traversal search is performed by using the Fibonacci search method.

5. The current measurement method based on a three-axis magnetoresistance according to claim 1, characterized in that, the method further includes: When there is no interfering magnetic field, the current I of the wire to be measured is calculated according to the magnetic field vectors detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and ​ 6. A current measurement system based on a three-axis magnetoresistance, characterized in that, the system is used to implement the current measurement method based on a three-axis magnetoresistance described in claim 1, the system is implemented based on a current sensing device, the current sensing device includes a first three-axis TMR current sensor, a second three-axis TMR current sensor, and a third three-axis TMR current sensor, and the magnetic sensitive directions of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are the same as the X-axis, Y-axis, and Z-axis of a preset three-dimensional coordinate system O-XYZ respectively, and the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor are located at points L, M, and N in the three-dimensional coordinate system O-XYZ respectively; the system includes: A sensing signal acquisition unit, configured to acquire magnetic field vectors detected by the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor and A calculation unit, configured to determine a disturbance magnetic field vector according to the magnetic field vector when there is a uniform disturbance magnetic field Determine the magnitude of the disturbance magnetic field vector The magnitude The magnitude range of the disturbance magnetic field vector, and the relative angle range between the disturbance magnetic field vector And the magnetic field vector There is a relative angle range between them; A search unit for traversing and searching for an amplitude value based on the amplitude range and the angle range and an included angle θ such that, in the case of eliminating the interference magnetic field , according to the actual magnetic field vectors of the first three-axis TMR current sensor, the second three-axis TMR current sensor, and the third three-axis TMR current sensor , the currents I 10 , I 20 , and I 30 calculated respectively satisfy preset conditions, that is, stop the search, and determine the current I of the wire to be measured according to the I 10 , I 20 , and I 30 .

7. A computer-readable storage medium, on which a computer program is stored, characterized in that, when the computer program is executed by a processor, it implements the steps of the current measurement method based on a three-axis magnetoresistance described in any one of claims 1 to 5.

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