Current sensor, current measurement system and method based on TMR chip array

Abstract

The present invention discloses a current sensor, current measurement system, and method based on a TMR chip array. The system utilizes four single-axis TMR chips. The four chips are located on the same imaginary circle, with each chip located at a quarter point of the imaginary circle. The magnetic sensitivity axes of the four chips are tangent to the imaginary circle in a clockwise direction. Each of the four chips is used to obtain the magnetic induction intensity induced at each chip by the current flowing through the conductor under test. The obtained magnetic induction intensity values ​​are used to calculate the current flowing through the conductor under test. The present invention utilizes four single-axis TMR chips, requiring fewer chips for current measurement. The current calculation method is simple, and compared to current transformers, the system is inexpensive, consumes less power, and has higher sensitivity. Furthermore, the system requires no circuitry, making the testing method safer and simpler.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical signal measurement, and in particular to a current sensor based on a TMR chip array, a current measurement system and a method. Background Art

[0002] With the rapid development of smart grids in recent years, the development and application of sensor technology for the rapid and accurate measurement of electrical and non-electrical quantities has become a significant challenge. For electrical quantities, such as voltage, current, and power, the requirements for sensor technology are becoming increasingly stringent. As a key technology in smart grids, current measurement is crucial for achieving rapid, accurate, safe, convenient, and cost-effective current measurement.

[0003] Traditional current measurement techniques primarily rely on current transformers. However, current transformers suffer from low bandwidth, easily saturated cores, and large size, resulting in slow response, high measurement costs, and cumbersome testing during actual current measurement. In recent years, sensors based on the tunnel magnetoresistance effect have gained popularity in the field of current measurement due to their small size, low power consumption, and high sensitivity. For example, the current sensor, current measurement device, system, apparatus, and storage medium disclosed in Chinese patent CN113049874A utilize a ring array and four first-axis TMR chips and two second-axis TMR chips to measure current signals. However, these sensors also suffer from the high number of TMR chips consumed, the complex current calculation method, high power consumption, high cost, and cumbersome testing.

[0004] In view of this, a current sensor, a current measurement system and a method based on a TMR chip array are needed. Summary of the Invention

[0005] The embodiments of the present invention provide a current sensor, a current measurement system, and a method based on a TMR chip array, so as to at least solve the technical problems of high TMR chip cost and complex current calculation method in the related art.

[0006] The present invention aims to achieve current measurement with fewer TMR chips, lower cost, lower power consumption, simpler testing method and more concise current calculation method under the premise of ensuring higher measurement accuracy.

[0007] According to one aspect of an embodiment of the present invention, a current sensor based on a TMR chip array is provided, comprising:

[0008] Four uniaxial TMR chips form a circular array; wherein the four uniaxial TMR chips are located on the same imaginary circle, and each of the uniaxial TMR chips is located at a quarter point of the circumference of the imaginary circle; the magnetic sensitive axis directions of the four uniaxial TMR chips are tangent to the imaginary circle in the same clockwise direction.

[0009] Optionally, each of the single-axis TMR chips is used to collect the magnetic induction intensity induced by the current to be measured in each of the single-axis TMR chips; and the value of the current to be measured is calculated using the magnetic induction intensity and the radius of the imaginary circle.

[0010] According to another aspect of an embodiment of the present invention, a current measurement method is further provided. The current measurement method uses the above-mentioned current sensor and includes:

[0011] collecting the magnetic induction intensity induced by the current to be measured at each of the four single-axis TMR chips;

[0012] The current value flowing through the wire to be measured is calculated based on the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle.

[0013] Optionally, calculating the value of the current to be measured according to the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle includes:

[0014] Establishing a current calculation formula, wherein the current calculation formula includes a corresponding relationship between a magnetic induction intensity variable, an imaginary circle radius variable, and a current variable to be measured;

[0015] The magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle are substituted into the current calculation formula to calculate the value of the current to be measured.

[0016] Optionally, establishing a current calculation formula specifically includes:

[0017] Step 1: The four single-axis TMR chips respectively collect the magnetic induction intensity B induced by the current to be measured at each chip. t , where t is a subscript representing the number of the four single-axis TMR chips, and the line connecting chips No. 1 and No. 3 is perpendicular to the line connecting chips No. 2 and No. 4;

[0018] Step 2: Construct the magnetic induction intensity B collected by the four uniaxial TMR chips t , the real magnetic induction intensity B' induced by the measured current at each chip t and B detected by the same single-axis TMR chip t and B't The angle α between t The equation relationship between

[0019] Step 3: Establish the measured current I and the distance R from each single-axis TMR chip to the measured wire according to Ampere's law. t and the true magnetic induction intensity B' t The equation relationship between

[0020] Step 4: construct the angle α according to the law of cosines within the triangle formed by the offset distance of the test conductor, the radius of the imaginary circle, and the offset distance from each TMR chip to the test conductor. t The radius R of the imaginary circle, the offset distance M of the conductor to be tested, and the distance R from each TMR chip to the conductor to be tested are t The equation relationship between

[0021] Step 5: In the triangle formed by the diameter of the imaginary circle and the distance from the two opposite TMR chips to the test conductor, construct the angle α according to the cosine theorem. t The radius R of the imaginary circle and the distance R from the two opposite TMR chips to the wire to be tested t 、R t+2 The equation relationship between

[0022] Step 6: Construct a calculation formula for the measured current I based on the equations established in steps 1 to 5, that is, obtain a current calculation formula, which is expressed as:

[0023] aI 2 +bI+c=0

[0024] in,

[0025] a=-4πB1Rμ0 2 +4πB2Rμ0 2 -4πB3Rμ0 2 +4πB4Rμ0 2

[0026] b=32B1B3R 2 μ0π 2 -32B2B4R 2 μ0π 2

[0027] c=64B1B2B4R 3 π 3 -64B1B2B3R 3 π 3 -64B1B3B4R 3 π 3 +64B2B3B4R3 π 3

[0028] Where B1, B2, B3 and B4 are the magnetic induction intensities obtained by the four uniaxial TMR chips, and μ0 is the vacuum magnetic permeability;

[0029] Optionally, substituting the magnetic induction intensity induced by the current to be measured at each of the uniaxial TMR chips and the radius of the imaginary circle into the current calculation formula to calculate the current value to be measured specifically includes:

[0030] Calculating a plurality of current values ​​to be selected according to the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle;

[0031] A true current value is identified from the plurality of current measurement values ​​to be selected.

[0032] Optionally, identifying the true current value from the plurality of current measurement values ​​to be selected specifically includes:

[0033] Calculating the distance from the conductor to be measured corresponding to each current measurement value to be selected to the center of the imaginary circle based on the current measurement values ​​to be selected, the magnetic induction intensities induced by the current to be measured at each uniaxial TMR chip, and the radius of the imaginary circle;

[0034] Determining whether the distance from the wire to be measured to the center of the imaginary circle corresponding to each of the current measurement values ​​to be selected is less than the radius of the imaginary circle;

[0035] If it is less than, then the current measurement value to be selected is the true current value.

[0036] According to another aspect of an embodiment of the present invention, there is further provided a current measurement system, comprising the above-mentioned current sensor and a microprocessor connected to the current sensor;

[0037] The current sensor is used to collect the current to be measured;

[0038] The microprocessor is used in any of the above-mentioned current measurement methods to calculate the value of the current to be measured according to the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle.

[0039] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is provided, which includes a stored program. When the program is executed, the device where the computer-readable storage medium is located is controlled to execute any one of the current measurement methods described above.

[0040] Compared with the existing technology, the present invention has the following beneficial effects:

[0041] 1. In an embodiment of the present invention, a current sensor employs four single-axis TMR chips. The four single-axis TMR chips are located on the same imaginary circle, with each TMR chip located at a quarter point of the imaginary circle. The magnetic sensitivity axes of the four single-axis TMR chips are tangent to the imaginary circle in a clockwise direction. Each of the four single-axis TMR chips is used to obtain the magnetic induction intensity induced at each chip by the current to be measured flowing through the conductor to be measured. The obtained magnetic induction intensity values ​​are used to calculate the current value flowing through the conductor to be measured. The single-axis TMR chips employed in this embodiment are relatively inexpensive, require relatively few TMR chips, and do not require circuit connection like current transformers. This makes the entire current testing process simple and safe, and current calculation is quick and easy. The present invention employs four single-axis TMR chips, uses a relatively small number of chips for current measurement, and simplifies the current calculation method. Compared to current transformers, the present invention is inexpensive, consumes less power, has high sensitivity, and does not require circuit connection, making the testing method safer and simpler.

[0042] 2. In an embodiment of the present invention, the current measurement method collects the magnetic induction intensity induced by the measured current at each of the four uniaxial TMR chips; and calculates the current flowing through the measured conductor based on the magnetic induction intensity induced by the measured current at each of the uniaxial TMR chips and the radius of the imaginary circle. Therefore, the current flowing through the measured conductor can be calculated by simply determining the five known quantities, the magnetic induction intensity obtained by the four uniaxial TMR chips and the radius of the imaginary circle, from the current calculation formula. This demonstrates that the current measurement method of the present invention is simpler and faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 Schematic diagram of the structure of a ring-shaped TMR chip array sensor in one embodiment of the present invention;

[0045] Figure 2 A schematic structural diagram of a current measurement system according to an embodiment of the present invention;

[0046] Figure 3 is a flow chart of a current measurement method according to an embodiment of the present invention;

[0047] Figure 4A schematic structural diagram of a current measurement system according to an embodiment of the present invention;

[0048] Among them, 11 is a single-axis TMR chip; 13 is a conductor to be tested. DETAILED DESCRIPTION

[0049] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0050] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0052] Example 1

[0053] like Figure 1 As shown, Figure 1 This is a structural block diagram of the annular TMR chip array sensor provided in this example. This current sensor includes: four uniaxial TMR chips 11, and the four uniaxial TMR chips 11 form a ring array; wherein the four uniaxial TMR chips 11 are located on the same imaginary circle, and each uniaxial TMR chip 11 is located at a quarter point of the circumference of the imaginary circle; the magnetic sensitive axis directions of the four uniaxial TMR chips 11 are tangent to the imaginary circle in the same clockwise direction.

[0054] The four single-axis TMR chips 11 are used to collect the magnetic induction intensity induced by the current to be measured flowing through the conductor to be measured 13 in each single-axis TMR chip 11; the magnetic induction intensity and the radius of the imaginary circle are used to calculate the current value to be measured.

[0055] Specifically, the current sensor based on the TMR chip array is composed of four uniaxial TMR chips 11. The four uniaxial TMR chips 11 are all located on the same imaginary circle. Each TMR chip is located at a quarter point of the circumference of the imaginary circle, and the magnetic sensitive axes of the four uniaxial TMR chips 11 are tangent to the imaginary circle in the clockwise direction. The four TMR chips are numbered for easy identification. The four uniaxial TMR chips 11 are sequentially labeled TMR1, TMR2, TMR3, and TMR4; and the line connecting TMR1 and TMR3 is perpendicular to the line connecting TMR2 and TMR4. It is worth noting that the positions of the four uniaxial TMR chips 11 are not fixed. As long as their relative positions remain unchanged, each uniaxial TMR chip 11 can be installed at any position on the circumference of the imaginary circle.

[0056] Example 2

[0057] According to an embodiment of the present invention, an embodiment of a current measurement method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0058] Figure 2 FIG. 1 is a flow chart of a current measurement method according to an embodiment of the present invention. Figure 2 As shown, the current measurement method includes the following steps:

[0059] Step S1 : collecting the magnetic induction intensity induced by the current to be measured at each of the four single-axis TMR chips 11 .

[0060] like Figure 1 As shown in the schematic diagram of the provided current sensor, the radius of the imaginary circle is set to R; the current flowing through the conductor 13 to be measured is set to I; the distance the conductor is offset from the center of the imaginary circle is set to M; the distances from TMR1, TMR2, TMR3 and TMR4 to the conductor 13 to be measured are set to R1, R2, R3 and R4 respectively; the magnetic induction intensities obtained by TMR1, TMR2, TMR3 and TMR4 at their respective positions are set to B1, B2, B3 and B4; the actual magnetic induction intensities induced at TMR1, TMR2, TMR3 and TMR4 by the current I flowing through the conductor 13 to be measured are set to B'1, B'2, B'3 and B'4; the angles between B1, B2, B3 and B4 and B'1, B'2, B'3 and B'4 are set to α1, α2, α3 and α4 respectively; since the imaginary circle is preset, the radius of the imaginary circle is a known parameter.

[0061] Step S2: Calculate the current value flowing through the measured conductor 13 according to the magnetic induction intensity induced by the measured current at each uniaxial TMR chip 11 and the radius of the imaginary circle.

[0062] Step S2 specifically includes the following steps:

[0063] Step S21: Establish a current calculation formula. The current calculation formula includes the corresponding relationship between the magnetic induction intensity variable, the imaginary circle radius variable, and the current variable to be measured, specifically including:

[0064] Step S211: The four single-axis TMR chips 11 respectively collect the magnetic induction intensity B induced by the current to be measured at each chip. t , where t is a subscript representing the numbering of the four single-axis TMR chips 11, and the line connecting chips No. 1 and No. 3 is perpendicular to the line connecting chips No. 2 and No. 4.

[0065] Step S212: construct the magnetic induction intensity B1, B2, B3, B4 collected by the four uniaxial TMR chips 11, the real magnetic induction intensity B'1, B'2, B'3, B'4 induced by the current to be measured at each chip, and the B detected by the same uniaxial TMR chip 11. t and B' t The angle α between t The equation relationship between:

[0066] B1=B'1cosα1 (1)

[0067] B2=B'2cosα2 (2)

[0068] B3=B'3cosα3 (3)

[0069] B4=B'4 cosα4 (4)

[0070] Step S213: Establish the measured current I, the distances R1, R2, R3 and R4 from TMR1, TMR2, TMR3 and TMR4 to the measured wire and the real magnetic induction intensity B' according to Ampere's law. t The equation relationship between:

[0071]

[0072] In the above formula, μ0 is the magnetic permeability in vacuum.

[0073] Step S214: In the triangle formed by the offset distance of the conductor to be tested, the radius of the imaginary circle, and the offset distances from each TMR chip to the conductor to be tested, an equation is constructed based on the law of cosines to represent the relationship between the angles α1, α2, α3, and α4 and the radius R of the imaginary circle, the offset distance M of the conductor to be tested, and the distances R1, R2, R3, and R4 from each TMR chip to the conductor to be tested:

[0074]

[0075] Step S215: In the triangle formed by the diameter of the imaginary circle and the distances from the two opposing TMR chips to the conductor to be tested, according to the law of cosines, construct equations for the angles α1, α2, α3, and α4, the radius R of the imaginary circle, and the distances R1, R3 and R2, R4 from the two opposing TMR chips to the conductor to be tested:

[0076]

[0077] Step S216: Construct a calculation formula for the measured current I based on the equations established in steps S212 to S215, to obtain the current calculation formula:

[0078] aI 2 +bI+c=0 (17)

[0079] in,

[0080] a=-4πB1Rμ0 2 +4πB2Rμ0 2 -4πB3Rμ0 2 +4πB4Rμ0 2

[0081] b=32B1B3R 2 μ0π 2 -32B2B4R 2 μ0π 2

[0082] c=64B1B2B4R 3 π 3 -64B1B2B3R 3 π 3 -64B1B3B4R 3 π 3 +64B2B3B4R 3 π 3

[0083] In the above equation, B1, B2, B3, and B4 are the magnetic induction intensities detected by the four uniaxial TMR chips on the circumference of an imaginary circle—namely, TMR1, TMR2, TMR3, and TMR4. R is the radius of the imaginary circle, and μ0 is the magnetic permeability of vacuum, all of which are known quantities. Therefore, the current I flowing through the conductor under test can be calculated based on only these five known quantities: B1, B2, B3, B4, and R.

[0084] Step S22: Substitute the magnetic induction intensity induced by the current to be measured at each single-axis TMR chip and the radius of the imaginary circle into the current calculation formula to calculate the current value to be measured.

[0085] Step S22 specifically includes:

[0086] Step S221, calculating a plurality of current values ​​to be selected based on the magnetic induction intensity induced by the current to be measured at each single-axis TMR chip and the radius of the imaginary circle;

[0087] Step S222, identifying the true current value from the multiple current measurement values ​​to be selected, specifically includes:

[0088] Based on the measured values ​​of each current to be selected, the magnetic induction intensities induced by the current to be measured at each single-axis TMR chip, and the radius of the imaginary circle, the distance from the conductor to be measured to the center of the imaginary circle corresponding to each current measurement value to be selected is calculated; based on the distance from the conductor to be measured to the center of the imaginary circle corresponding to each current measurement value to be selected, it is determined whether the distance from the conductor to be measured to the center of the imaginary circle is less than the radius of the imaginary circle; if less, then the measured value of the current to be selected is the true current value.

[0089] The above embodiment describes the current sensor in detail. Figure 1 As shown, the magnetic induction intensities obtained by the current sensor are combined with the radius of the preset imaginary circle to calculate the current value flowing through the wire to be measured. Now, an embodiment is used to further illustrate how to filter out the true current value flowing through the wire to be measured from the calculated current measurement values ​​to be selected. Figure 2 As shown, in step S21, the current measurement values ​​to be selected are calculated according to the magnetic induction intensity obtained by each single-axis TMR chip and the radius of the imaginary circle. The steps are as follows:

[0090] After calculations in steps S211-S215, combining equations (1)-(12), we can obtain:

[0091]

[0092] In calculation step S216, combining equations (13)-(16) and equations (18)-(21), we can obtain:

[0093]

[0094] Combining equations (18), (20), and (22), we can obtain:

[0095]

[0096] Substituting the magnetic induction intensity values ​​B1 and B3 obtained by TMR1 and TMR3, the radius R of the set imaginary circle, and the current measurement value I to be selected into formula (23), the distance M from the measured conductor to the center of the imaginary circle can be solved.

[0097] In this embodiment, in order to filter out the true current value flowing through the conductor to be measured from the calculated current measurement values ​​to be selected, the magnetic induction intensity values ​​B1 and B3 obtained by TMR1 and TMR3 (or the magnetic induction intensity values ​​B2 and B4 obtained by TMR2 and TMR4), the radius R of the set imaginary circle, and the current measurement value to be selected I are used to solve the distance M between the conductor to be measured and the center of the imaginary circle, and this distance M is compared with the radius R of the set imaginary circle, so as to determine that when the distance M between the conductor to be measured and the center of the imaginary circle is less than the radius R of the set imaginary circle, the current measurement value to be selected I is the true current value flowing through the conductor to be measured.

[0098] The above embodiment describes how to filter out the true current value flowing through the wire to be measured from the calculated current measurement values ​​to be selected. Now, an embodiment is used to further describe the current measurement method provided by this application. Figure 3 As shown, it includes the following steps:

[0099] S302, obtaining the magnetic induction intensities of four uniaxial TMR chips on the circumference of a preset imaginary circle.

[0100] S304: Obtain the radius parameter of the preset imaginary circle.

[0101] S306: Obtain a distance parameter of the measured conductor deviating from the center of the imaginary circle.

[0102] S308: Obtain the distance parameters from each single-axis TMR chip to the conductor to be measured.

[0103] S310 , obtaining an angle parameter between a magnetic field induced by the current to be measured at each single-axis TMR chip and a magnetic sensitive axis of each single-axis TMR chip.

[0104] S312: Establish a calculation formula for the current value to be measured based on the obtained magnetic induction intensity of each uniaxial TMR chip, the radius parameter of the imaginary circle, the distance parameter of the measured conductor from the center of the imaginary circle, the distance parameter from each uniaxial TMR chip to the measured conductor, and the angle parameter between the magnetic field induced at each uniaxial TMR chip and the magnetic sensitive axis of each uniaxial TMR chip.

[0105] S314 , substituting the known magnetic induction intensity of each uniaxial TMR chip and the radius of the imaginary circle into the established current value calculation formula to calculate each current measurement value to be selected.

[0106] S316 , using the magnetic induction intensities of the two uniaxial TMR cores with opposite magnetic sensitive axes, the radius of the set imaginary circle, and the current measurement value to be selected, calculate the distance that the conductor to be measured deviates from the center of the imaginary circle.

[0107] S318: Determine whether the distance of the measured conductor from the center of the imaginary circle is less than the radius of the set imaginary circle.

[0108] S320: If so, then the current measurement value to be selected is the actual current value flowing through the conductor to be measured.

[0109] In this embodiment, the calculation of each current measurement value to be selected can be achieved only by using the magnetic induction intensity of four uniaxial TMR chips on the known imaginary circle and the radius of the imaginary circle. At the same time, the actual current value flowing through the conductor to be tested can also be screened out from the calculated current measurement values ​​to be selected. The testing method is simple and consumes a small number of TMR chips.

[0110] In this embodiment, the calculation of each current measurement value to be selected can be achieved only by using the magnetic induction intensity of four uniaxial TMR chips on the known imaginary circle and the radius of the imaginary circle. At the same time, the actual current value flowing through the conductor to be tested can also be screened out from the calculated current measurement values ​​to be selected. The testing method is simple and consumes a small number of TMR chips.

[0111] Example 3

[0112] The above embodiment describes in detail the current measurement method applied to the current sensor based on the ring TMR chip array. Figure 3 As shown, the magnetic induction intensity and the radius of the preset imaginary circle obtained by the current sensor are used to calculate the current value flowing through the conductor to be measured. The current value calculation is completed by a microprocessor connected to the current sensor. Now, an embodiment of a current measurement system composed of a current sensor and a microprocessor connected thereto is further described. In one embodiment, as Figure 4 The current measurement system shown includes: a current sensor 41 based on a ring-shaped TMR chip array and a microprocessor 42 connected thereto;

[0113] The microprocessor connected to the current sensor is used to calculate each current measurement value to be selected according to the magnetic induction intensity collected by the current sensor and the radius of the imaginary circle, and select the real current value flowing through the current.

[0114] Furthermore, after collecting the magnetic induction intensity of each chip, the current sensor based on the annular TMR chip array sends the data to the microprocessor connected to it. The microprocessor calculates the true current value flowing through the conductor to be measured based on the current measurement method and the true current value screening method in the above embodiment.

[0115] In an embodiment, the current measurement system includes a current sensor based on a ring-shaped TMR chip array and a microprocessor connected thereto; the current sensor based on the ring-shaped TMR chip array is used to collect the magnetic induction intensity of each single-axis TMR chip; the microprocessor calculates the actual current value flowing through the conductor to be measured based on the magnetic induction intensity transmitted by the current sensor and the radius of a preset imaginary circle. The system has a simple structure and is easy to test.

[0116] In summary, the present invention can achieve low-cost, safer, and simpler current measurement with a smaller number of single-axis TMR chips.

[0117] The present invention is not limited to the above specific implementation methods. The above are only preferred implementation cases of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0118] Example 4

[0119] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is provided, which includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute any one of the above current measurement methods.

[0120] Optionally, in this embodiment, the computer-readable storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group, and the computer-readable storage medium includes a stored program.

[0121] Optionally, when the program is running, the device where the computer-readable storage medium is located is controlled to perform the following functions: collecting the magnetic induction intensity induced by the current to be measured at each of the four single-axis TMR chips; and calculating the current value flowing through the conductor to be measured based on the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle.

[0122] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0123] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0124] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the system embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of units or modules can be electrical or other forms.

[0125] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0126] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0127] If the integrated unit 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. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-0nly Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, etc., various media that can store program code.

[0128] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A current measurement method, using a current sensor based on a TMR chip array, wherein the current sensor based on the TMR chip array includes four single-axis TMR chips, and the four single-axis TMR chips form a ring array; wherein: The four uniaxial TMR chips are located on the same imaginary circle, and each of the uniaxial TMR chips is located at a quarter point of the circumference of the imaginary circle; the magnetic sensitive axes of the four uniaxial TMR chips are tangent to the imaginary circle in the same clockwise direction; the invention is characterized by: collecting the magnetic induction intensity induced by the current to be measured at each of the four single-axis TMR chips; Calculating the current value flowing through the wire to be measured based on the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle, specifically including: Establish a current calculation formula, the current calculation formula includes a correspondence between a magnetic induction intensity variable, an imaginary circle radius variable, and a current variable to be measured; the establishment of the current calculation formula specifically includes: Step 1: The four single-axis TMR chips respectively collect the magnetic induction intensity B induced by the current to be measured at each chip. t , where t is a subscript representing the number of the four single-axis TMR chips, and the line connecting chips No. 1 and No. 3 is perpendicular to the line connecting chips No. 2 and No. 4; Step 2: Construct the magnetic induction intensity B collected by the four uniaxial TMR chips t , the real magnetic induction intensity B' induced by the measured current at each chip t and B detected by the same single-axis TMR chip t and B' t The angle α between t The equation relationship between Step 3: Establish the measured current I and the distance R from each single-axis TMR chip to the measured wire according to Ampere's law. t and the true magnetic induction intensity B' t The equation relationship between Step 4: construct the angle α according to the law of cosines within the triangle formed by the offset distance of the test conductor, the radius of the imaginary circle, and the offset distance from each TMR chip to the test conductor. t The radius R of the imaginary circle, the offset distance M of the conductor to be tested, and the distance R from each TMR chip to the conductor to be tested are t The equation relationship between Step 5: In the triangle formed by the diameter of the imaginary circle and the distance from the two opposite TMR chips to the test wire, construct the angle α according to the cosine theorem. t The radius R of the imaginary circle and the distance R from the two opposite TMR chips to the wire to be tested t 、R t+2 The equation relationship between Step 6: Construct a calculation formula for the measured current I based on the equations established in steps 1 to 5, that is, obtain a current calculation formula, which is expressed as: you 2 +bI+c=0 in, a=-4πB1Rμ0 2 +4πB2Rμ0 2 -4πB3Rμ0 2 +4πB4Rμ0 2 b=32B1B3R 2 m0p 2 -32B2B4R 2 m0p 2 c=64B1B2B4R 3 p 3 -64B1B2B3R 3 p 3 -64B1B3B4R 3 p 3 +64B2B3B4R 3 p 3 Where B1, B2, B3 and B4 are the magnetic induction intensities obtained by the four uniaxial TMR chips, and μ0 is the vacuum magnetic permeability; The magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle are substituted into the current calculation formula to calculate the value of the current to be measured.

2. The current measurement method according to claim 1, characterized in that: Substituting the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle into the current calculation formula to calculate the current value to be measured, specifically including: Calculating a plurality of current values ​​to be selected according to the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle; A true current value is identified from the plurality of current measurement values ​​to be selected.

3. The current measurement method according to claim 2, characterized in that: Identifying the true current value from the plurality of current measurement values ​​to be selected specifically includes: Calculating the distance from the conductor to be measured corresponding to each current measurement value to be selected to the center of the imaginary circle based on the current measurement values ​​to be selected, the magnetic induction intensities induced by the current to be measured at each uniaxial TMR chip, and the radius of the imaginary circle; Determining whether the distance from the wire to be measured to the center of the imaginary circle corresponding to each of the current measurement values ​​to be selected is less than the radius of the imaginary circle; If it is less than, then the current measurement value to be selected is the true current value.

4. A current measurement system, characterized in that: Used to implement the current measurement method according to any one of claims 1 to 3, comprising a current sensor based on a TMR chip array and a microprocessor connected to the current sensor; The current sensor based on the TMR chip array includes four uniaxial TMR chips, and the four uniaxial TMR chips form a ring array; wherein the four uniaxial TMR chips are located on the same imaginary circle, and each uniaxial TMR chip is located at a quarter point of the circumference of the imaginary circle; the magnetic sensitive axes of the four uniaxial TMR chips are tangent to the imaginary circle in the same clockwise direction; the current sensor based on the TMR chip array is used to collect the current to be measured; The microprocessor is used to calculate the value of the current to be measured according to the magnetic induction intensity induced by the current to be measured at each of the single-axis TMR chips and the radius of the imaginary circle.

5. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the current measurement method according to any one of claims 1 to 3.

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