Current sensor and current measurement method

Abstract

The application relates to a current sensor and a current measurement method. The current sensor comprises a magnetoresistance sensing unit for measuring the magnetic induction intensity of a cable to be measured; a driving assembly connected with the magnetoresistance sensing unit and used for driving the magnetoresistance sensing unit to perform linear motion; and a control module connected with the magnetoresistance sensing unit and the driving assembly respectively, used for controlling the driving assembly to drive the magnetoresistance sensing unit to move along a preset direction, and used for respectively acquiring the magnetic induction intensity detected by the magnetoresistance sensing unit at multiple different preset positions, and acquiring the current value of the cable to be measured according to the magnetic induction intensity detected at the multiple different preset positions. The current sensor adopted by the application has the advantages of simple structure, low cost and easy installation, and can avoid the inconsistency problem when the magnetic induction intensity of multiple different positions is detected by using a magnetoresistance sensing array, and the accuracy of the detection result is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, in particular to a current sensor and a current measurement method. BACKGROUND

[0002] With the development of smart grid, higher requirements are put forward for the sensing and monitoring of electrical quantities. The commonly used data acquisition device at present is a current transformer. The current transformer measures the magnetic induction intensity of the cable and then calculates the current value of the cable, which can meet the basic demand of smart grid for comprehensive and real-time sensing information.

[0003] In the traditional current sensor, multiple magnetoresistance sensing units are arranged to realize current detection, but the volume is large and it is not convenient to install universally. SUMMARY

[0004] Therefore, it is necessary to provide a current sensor with low cost, small volume and easy installation in view of the above technical problems.

[0005] In a first aspect, the present application provides a current sensor. The current sensor comprises:

[0006] a magnetoresistance sensing unit, configured to measure the magnetic induction intensity of a to-be-measured cable;

[0007] a driving assembly, connected with the magnetoresistance sensing unit, configured to drive the magnetoresistance sensing unit to move linearly;

[0008] a control module, connected with the magnetoresistance sensing unit and the driving assembly respectively, configured to control the driving assembly to drive the magnetoresistance sensing unit to move along a preset direction, and correspondingly acquire the magnetic induction intensity detected by the magnetoresistance sensing unit at multiple different preset positions, and acquire the current value of the to-be-measured cable according to the magnetic induction intensity detected at the multiple different preset positions.

[0009] In one of the embodiments, the movement direction of the magnetoresistance sensing unit is the same as the magnetic sensitive direction of the magnetoresistance sensing unit.

[0010] In one of the embodiments, the control module is further configured to control the driving assembly to drive the magnetoresistance sensing unit to move along a preset direction and move to four different preset positions, and acquire the relative distance between any preset position and the initial position and the magnetic induction intensity of the magnetoresistance sensing unit at each preset position respectively; wherein,

[0011] the control module is further configured to acquire the current value of the to-be-measured cable according to the relative distance and the magnetic induction intensity.

[0012] In one of the embodiments, the current sensor further comprises:

[0013] The ranging module is connected with the control module, and is arranged on the same straight line with the driving assembly and the magnetoresistance sensing unit, and is configured to measure position information of the magnetoresistance sensing unit at different preset positions;

[0014] The control module is further configured to correspondingly acquire the magnetic induction intensity detected by the magnetoresistance sensing unit at each different preset position, acquire the relative distance between any preset position and the initial position according to the position information of the magnetoresistance sensing unit, and acquire the current value of the cable to be measured according to the relative distance and the magnetic induction intensity.

[0015] In one of the embodiments, the ranging module comprises a laser ranging module.

[0016] In one of the embodiments, the relative distances of any two adjacent preset positions are the same.

[0017] In one of the embodiments, the driving assembly comprises a driving motor, a driving shaft, and a driving block arranged on the driving shaft, and the magnetoresistance sensing unit is arranged on the driving block, and the driving motor is configured to drive the driving block to move the magnetoresistance sensing unit along the driving shaft.

[0018] In one of the embodiments, the current sensor further comprises an induction area for placing the cable to be measured, and the moving range of the magnetoresistance sensing unit driven by the driving assembly to move along the preset direction is located in the induction range of the magnetoresistance sensing unit to detect the magnetic induction intensity of the cable to be measured.

[0019] The current sensor comprises a magnetoresistance sensing unit, a driving assembly, and a control module, wherein the magnetoresistance sensing unit measures the magnetic induction intensity of the cable to be measured, the driving assembly drives the magnetoresistance sensing unit to move linearly, the control module controls the driving assembly to drive the magnetoresistance sensing unit to move along a preset direction, and correspondingly acquires the magnetic induction intensity detected by the magnetoresistance sensing unit at multiple different preset positions, and the control module acquires the current value of the cable to be measured according to the magnetic induction intensity detected at the multiple different preset positions, thereby realizing current measurement. Compared with the scheme of using a magnetoresistance sensing array composed of multiple magnetoresistance sensing units to detect the magnetic induction intensity at multiple different positions, the number of magnetoresistance sensing units can be reduced, the structure is simple, the cost is low, and the installation is easy, and the inconsistency problem existing in the detection of the magnetic induction intensity at multiple different positions by using the magnetoresistance sensing array can be avoided, thereby improving the accuracy of the detection result.

[0020] In a second aspect, the application further provides a current measurement method. The method comprises:

[0021] controlling the driving assembly to drive the magnetoresistance sensing unit to move along a preset straight line direction;

[0022] respectively correspond to the magnetic induction intensity detected by the magnetoresistance sensing unit at a plurality of different preset positions;

[0023] According to each of the preset positions and the corresponding detected magnetic induction intensity, the current value of the cable to be measured is obtained.

[0024] In one embodiment, according to each of the preset positions and the corresponding detected magnetic induction intensity, the current value of the cable to be measured is obtained, comprising:

[0025] Four different preset positions are set, and the relative distance between any preset position and the initial position is obtained respectively;

[0026] According to each of the relative distances and the magnetic induction intensity corresponding to each of the preset positions, the current value of the cable to be measured is obtained.

[0027] The above current measurement method, by controlling the driving assembly to drive the magnetoresistance sensing unit to move along the preset straight line direction, respectively correspond to the magnetic induction intensity detected by the magnetoresistance sensing unit at a plurality of different preset positions, and according to each of the preset positions and the corresponding detected magnetic induction intensity, the current value of the cable to be measured is obtained, realizing the measurement of the current of the cable to be measured. This method avoids the inconsistency of multiple magnetoresistance sensing units when using a magnetoresistance sensing array to detect the magnetic induction intensity at multiple different positions, thereby improving the measurement accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The output characteristic curve of a plurality of magnetoresistance sensing units of the same model;

[0029] Figure 2 The structural block diagram of the current sensor in one embodiment;

[0030] Figure 3 The internal structural block diagram of the magnetoresistance sensing unit;

[0031] Figure 4 The schematic diagram of the current sensor measuring the current of the current-carrying wire in one embodiment;

[0032] Figure 5 The structural block diagram of the current sensor in another embodiment;

[0033] Figure 6 The structural block diagram of the driving assembly in one embodiment;

[0034] Figure 7 The flowchart of the current measurement method in one embodiment;

[0035] Figure 8Flowchart of the current measurement method in another embodiment.

[0036] Explanation of reference signs:

[0037] 10 - magnetoresistance sensing unit, 20 - driving assembly, 201 - driving motor, 201 - driving shaft, 203 - driving block, 30 - control module, 40 - distance measurement module. DETAILED DESCRIPTION

[0038] In order to make the purposes, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0039] In the related art, a magnetoresistance sensing (Tunnel Magnetoresistance, TMR) unit array is generally used to measure current. The TMR unit array includes a plurality of TMR units at different positions.

[0040] When the TMR unit array is used to measure current, only the relatively linear part in the output characteristic curve thereof is generally used. However, due to errors caused by manufacturing process, the output characteristics of even the same type of TMR units will be different, that is, there is a problem that the TMR array outputs inconsistently under the same magnetic field. Figure 1 For the output characteristic curve of the same type of TMR units, the output voltage of the TMR units is different under the same applied magnetic field, which will cause the measured results of the magnetic field and the current to deviate from the true values.

[0041] Based on this, the present application proposes a current sensor, as shown in Figure 2 The current sensor includes a magnetoresistance sensing unit 10, a driving assembly 20 and a control module 30. The driving assembly 20 is connected with the magnetoresistance sensing unit 10, and the control module 30 is connected with the magnetoresistance sensing unit 10 and the driving assembly 20 respectively.

[0042] The magnetoresistance sensing unit 10 is used to measure the magnetic induction intensity of the to-be-measured cable. The to-be-measured cable is placed in the sensing range of the magnetoresistance sensing unit, and the magnetoresistance sensing unit can measure the magnetic induction intensity around the to-be-measured cable. The magnetoresistance sensing unit is usually composed of four resistors in a Wheatstone bridge structure, as shown in Figure 3 The resistors on the opposite corners of the bridge are the same. When there is an applied magnetic field, according to the magnetoresistance effect, the two resistors R1 and R2 on the same bridge arm are in linear relationship with the applied magnetic field and are opposite to the change trend of the applied magnetic field. Figure 1 In the formula, V SP -V SN The external power supply of the TMR unit is denoted as V S , VOP -V ON V is the output of the TMR unit O Then there is the following relationship:

[0043]

[0044] The resistances R1 and R2 have a linear relationship with the applied magnetic field within a certain magnetic field range, so the output voltage of the TMR unit has a linear relationship with the applied magnetic field within a certain range, that is:

[0045] V o =kB+b

[0046] Where B is the magnetic induction intensity to be measured, k and b are related parameters of the output characteristics of the TMR unit, k is the slope, and b is the linear intercept. Based on this, within the range of the TMR unit, the magnetic induction intensity of the applied magnetic field can be obtained according to the output voltage of the TMR unit.

[0047] The driving assembly 20 is used to drive the magnetoresistance sensing unit 10 to move linearly. The driving assembly 20 can include a stepping motor, a rotating motor, etc. Taking a stepping motor as an example, the rotor of the stepping motor is a permanent magnet. When current flows through the stator winding, the stator winding generates a vector magnetic field, which drives the rotor to rotate by a certain angle, so that a pair of magnetic field directions of the rotor are consistent with the magnetic field direction of the stator. And when the vector magnetic field of the stator rotates by a certain angle, the rotor will rotate by a certain angle along with the magnetic field. In this way, every input of an electric pulse, the rotor will rotate by a certain angle and move forward by a step. By changing the order of winding energization, the stepping motor will reverse. The rotation of the stepping motor can be controlled by controlling the number of pulses, the frequency and the order of winding energization, so as to drive the magnetoresistance sensing unit 10 to move.

[0048] The control module 30 can be used to control the driving assembly 20 to drive the magnetoresistance sensing unit 10 to move along a preset direction, and respectively correspondingly acquire the magnetic induction intensities detected by the magnetoresistance sensing unit 10 at a plurality of different preset positions, and acquire the current value of the cable to be measured according to the magnetic induction intensities detected at the plurality of different preset positions. The control module 30 can be integrated with the driving assembly 20 at the local end, or can be a computer device, such as a server, a computer, a mobile phone, a tablet computer, etc.

[0049] Specifically, the control module 30 issues a control instruction to the driving assembly 20, the control instruction including a control pulse number, a pulse frequency and a winding energization sequence of the motor, so as to make the driving assembly 20 drive the magnetoresistance sensing unit to move linearly along a preset direction, so as to move to different preset positions in turn. Then the control module 30 respectively acquires the magnetic induction intensities detected by the magnetoresistance sensing unit at a plurality of preset positions, and further calculates the current value of the cable to be measured according to the plurality of magnetic induction intensity data.

[0050] In this embodiment, the current sensor includes a magnetoresistive sensing unit 10, a driving component 20, and a control module 30. The magnetoresistive unit measures the magnetic flux density of the cable under test. The driving component 20 drives the magnetoresistive sensing unit 10 to move linearly. The control module 30 controls the driving component 20 to move the magnetoresistive sensing unit 10 along a preset direction, and acquires the magnetic flux density detected by the magnetoresistive sensing unit 10 at multiple different preset positions. The control module 30 obtains the current value of the cable under test based on the magnetic flux density detected at these positions, thus achieving current measurement. Compared to related technologies that use a magnetoresistive sensing array composed of multiple magnetoresistive sensing units to detect magnetic flux density at multiple different positions, this application reduces the number of magnetoresistive sensing units, has a simple structure, low cost, and is easy to install. It also avoids the inconsistency problem that exists when using a magnetoresistive sensing array to detect magnetic flux density at multiple different positions, improving the accuracy of the detection results.

[0051] In one embodiment, the current sensor has a sensing area for placing the cable under test. The range of movement of the magnetoresistive sensing unit 10 driven by the driving component 20 along a preset direction is within the sensing range of the magnetoresistive sensing unit 10 for detecting the magnetic induction intensity of the cable under test, ensuring that the magnetoresistive sensing unit 10 can detect the magnetic induction intensity of the cable under test at each preset position when measuring the cable current.

[0052] In one embodiment, the direction of motion of the magnetoresistive sensing unit 10 is the same as the magnetic sensitivity direction of the magnetoresistive sensing unit 10. The magnetic sensitivity direction indicates that a relatively small magnetic field is required for the magnetoresistive magnetization to reach saturation in that specific direction. Figure 4 As shown, H represents the magnetic sensing direction of the magnetoresistive sensing unit. The output of the magnetoresistive sensing unit 10 is only related to the magnetic field parallel to its magnetic sensing direction. Therefore, when measuring current, it is necessary to ensure that the movement direction of the magnetoresistive sensing unit 10 is on a straight line with the magnetic sensing direction of the magnetoresistive sensing unit, so that the magnetic sensing direction of the magnetoresistive sensing unit 10 at each preset position is parallel to the applied magnetic field, thereby improving the accuracy and sensitivity of the magnetoresistive sensing unit 10 in measuring magnetic induction intensity.

[0053] In one embodiment, the control module 30 is further configured to control the drive component 20 to drive the magnetoresistive sensing unit 10 to move along a preset direction and to four different preset positions, respectively obtaining the relative distance between any preset position and the initial position and the magnetic induction intensity of the magnetoresistive sensing unit 10 at each preset position.

[0054] For example, such as Figure 4As shown, four preset positions L1, L2, L3, L4 can be set, and the four preset positions are on a straight line, and the preset position L1 is taken as the initial position of the magneto-resistive sensing unit 10. The relative distances of L2, L3, L4 and the initial position L1 are set as m, n, k in the control module 30 in advance, and further, the control module 30 controls the driving assembly 20 to drive the magneto-resistive sensing unit 10 to move a corresponding distance by changing the number of control pulses sent to the driving assembly 20.

[0055] The control module 30 is further configured to obtain the current value of the cable to be measured according to the relative distances and the magnetic induction intensities. The principle of the control module 30 of the present application obtaining the current value of the cable to be measured according to the relative distances and the magnetic induction intensities will be described by taking the measurement of the current of the current-carrying wire as an example. Figure 4 In the formula, it is assumed that the current of the current-carrying wire is I x , B0 is the component of the external interference magnetic field in the magnetic sensitive direction of the magneto-resistive sensing unit 10; B1, B2, B3, B4 are the magnetic induction intensities measured by the magneto-resistive sensing unit 10 at the four preset positions; x1, x2, x3, x4 are the distances from the magneto-resistive sensing unit 10 at the four preset positions to the current-carrying wire; it is assumed that the perpendicular line segment of the current-carrying wire to the straight line where the four preset positions are located is d, the plane passing through the straight line where the four preset positions are located and perpendicular to the perpendicular line segment d is s, θ1, θ2, θ3, θ4 are the angles between the perpendicular line of the current-carrying wire and the plane s when the magneto-resistive sensing unit 10 is at the four preset positions (θ2, θ3, θ4 are not drawn), and the angle between the current-carrying wire and the normal plane of the straight line where the four preset positions are located is α. Let

[0056]

[0057] In the formula, μ0 is the magnetic permeability of vacuum, and according to the Biot-Savart law, the following formula can be obtained:

[0058]

[0059] According to the spatial geometric relationship between the preset positions and the current-carrying wire shown in the formula, the following formula can be obtained: Figure 4

[0060]

[0061] In the formula, B1, B2, B3, B4, m, n, k are known quantities, and let

[0062] x = x1 2 , B ij = B i -B j

[0063] The formula (2) and (3) are arranged to obtain:

[0064] 0 = ax​4 +bx 3 +cx 2 +dx+e (4)

[0065] For ease of description, the coefficients of the power function of x are represented as a, b, c, d, and e, and their specific values ​​are:

[0066]

[0067] Among them, a 1-3 b 1-3 c 1-9 It has no specific physical meaning; it is merely an intermediate quantity set up in the calculation process for the convenience of representing the values ​​of a, b, c, d, and e. Its specific value is:

[0068]

[0069] Substituting formula (6) into formula (5) yields the values ​​of a, b, c, d, and e. Then, substituting these values ​​into formula (4) solves the problem.

[0070] x=root[a,b,c,d,e] (7)

[0071] Then there is

[0072] Solving according to formulas (2), (3), and (7) yields the following results.

[0073]

[0074] The current I is obtained by solving the above formulas (1) to (8).

[0075]

[0076] The final current value of the current-carrying conductor is obtained.

[0077]

[0078] All of the above calculations are implemented by the control module 30 through an algorithm program.

[0079] In this embodiment, the control module 30 controls the drive component 20 to drive the magnetoresistive sensing unit 10 to move along the linear direction of the magnetic sensing unit 10 and move to four preset positions, with the first preset position as the initial position. Then, the control module 30 obtains the relative distance between any preset position and the initial position, as well as the magnetic induction intensity measured by the magnetoresistive sensing unit 10 at each preset position. Further, the current value of the cable under test is calculated based on each relative distance and each magnetic induction intensity, thereby achieving accurate current measurement.

[0080] In one embodiment, to reduce computational complexity, the relative distance between any two adjacent preset positions can be set to be the same.

[0081] In one embodiment, the current sensor further includes a ranging module. For example... Figure 5 As shown, the ranging module 40 is connected to the control module 30 and is arranged on the same straight line as the drive assembly 20 and the magnetoresistive sensing unit 10. It is used to measure the position information of the magnetoresistive sensing unit 10 at different preset positions. Furthermore, the control module 30 is also used to acquire the magnetic induction intensity detected by the magnetoresistive sensing unit 10 at each different preset position, to acquire the relative distance between any preset position and the initial position based on the position information of the magnetoresistive sensing unit 10, and to acquire the current value of the cable under test based on each relative distance and each magnetic induction intensity.

[0082] In this embodiment, the displacement accuracy of the driving component 20 itself is at the micrometer level, which can meet most application scenarios. However, when the current sensor is applied to scenarios with higher displacement accuracy, a ranging module 40 is needed to position the magnetoresistive sensing unit 10 so that the magnetoresistive sensing unit 10 can reach the preset position more accurately, and the position information of the magnetoresistive sensing unit 10 is sent to the control module 30. The ranging module 40 can be a high-precision laser ranging module or a nanometer displacement meter, etc.

[0083] The control module 30 calculates the relative distance between any preset position and the initial position based on the position information of the magnetoresistive sensing unit 10 sent by the ranging module, so as to adjust each relative distance preset in the control module 30, and obtain the magnetic induction intensity detected by the magnetoresistive sensing unit 10 at each different preset position. Furthermore, the current value of the cable under test is calculated by the above formulas (1) to (9).

[0084] In this embodiment, the magnetoresistive sensing unit 10 is precisely positioned by the ranging module 40, enabling it to accurately reach a preset position. The position information of the magnetoresistive sensing unit 10 at different preset positions is sent to the control module 30, so that the control module 30 can obtain the relative distance between any preset position and the initial position based on the position information. Based on each relative distance and the magnetic induction intensity detected at each preset position, the current value is calculated, thereby improving the accuracy of the measured current value.

[0085] In one embodiment, such as Figure 6As shown, the drive assembly 20 includes a drive motor 201, a drive shaft 202, and a drive block 203 mounted on the drive shaft. A magnetoresistive sensing unit 10 is mounted on the drive block 203. The drive assembly 20 drives the magnetoresistive sensing unit 10 to move along the drive shaft 202 via the drive block 203. For example, the drive assembly 20 can be an externally driven linear stepper motor. The lead screw and rotor of the externally driven linear stepper motor are integrated as the motor's output shaft, and a drive block is mounted on the lead screw. When the motor operates, the output shaft rotates, allowing the drive block to move back and forth on the output shaft, thereby causing the magnetoresistive sensing unit 10 to move linearly along the output shaft.

[0086] In this embodiment, the drive assembly includes a drive motor, a drive shaft, and a drive block mounted on the drive shaft. The drive motor rotates the drive shaft, and the drive block moves back and forth as the drive shaft rotates, thereby causing the magnetoresistive sensing unit to move linearly along the drive shaft and measure the magnetic induction intensity at multiple preset positions. This avoids the errors caused by the inconsistency of multiple magnetoresistive sensing units when using a magnetoresistive sensing array to measure current, and improves the accuracy of the measurement.

[0087] In one embodiment, this application also provides a current measurement method, using a current sensor from any of the above embodiments, such as... Figure 7 As shown, the current measurement method includes steps 702-706.

[0088] Step 702: Control the drive component to drive the magnetoresistive sensing unit to move along a preset straight line direction.

[0089] The control module in the current sensor can send control commands to the drive assembly. These control commands include the number of control pulses, pulse frequency, and the energizing sequence of the motor windings, so that the drive assembly drives the magnetoresistive sensing unit to move linearly along a preset direction, including forward and backward movement along the straight line. The preset straight line direction is the straight line along which the drive shaft of the drive assembly is located, and this straight line is collinear with the magnetic sensing direction of the magnetoresistive sensing unit.

[0090] Step 704: Obtain the magnetic induction intensity detected by the magnetoresistive sensing unit at multiple different preset positions.

[0091] Multiple preset positions are set, and these preset positions are collinear. When the control module controls the drive component to move the magnetoresistive sensing unit to each preset position, the control module acquires the magnetic induction intensity detected by the magnetoresistive sensing unit at that preset position.

[0092] Step 706: Obtain the current value of the cable under test based on each preset position and the corresponding detected magnetic induction intensity.

[0093] The control module calculates the current value of the cable under test based on the magnetic induction intensity detected by the magnetoresistive sensing unit at each preset position.

[0094] In this embodiment, a current sensor controls a driving component to move a magnetoresistive sensing unit along a preset linear direction. The magnetic flux density detected by the magnetoresistive sensing unit at multiple preset positions is then acquired. Based on each preset position and the corresponding detected magnetic flux density, the current value of the cable under test is obtained, thus achieving the measurement of the cable's current. Furthermore, using a current sensor to measure the current avoids the errors caused by the inconsistency of multiple magnetoresistive sensing units when measuring magnetic flux density using a magnetoresistive sensing array, thereby improving measurement accuracy.

[0095] In one embodiment, such as Figure 8 As shown, the current value of the cable under test is obtained according to each preset position and the corresponding detected magnetic induction intensity, including steps 802-804.

[0096] Step 802: Set four different preset positions and obtain the relative distance between any preset position and the initial position.

[0097] Four preset positions are set, with the first preset position serving as the initial position of the magnetoresistive sensing unit. The relative distance between any preset position and the initial position can be pre-set in the control module. The control module controls the driving component to drive the magnetoresistive sensing unit to move sequentially to the preset positions along a preset direction. In this embodiment, the displacement accuracy of the magnetoresistive sensing unit driven by the current sensor's driving component can reach the micrometer level, which can meet the needs of most application scenarios.

[0098] Step 804: Obtain the current value of the cable under test based on the relative distance and the magnetic induction intensity corresponding to each preset position.

[0099] The control module calculates the current value of the cable under test using formulas (1) to (9) based on the relative distance and the magnetic induction intensity collected by the magnetoresistive sensing unit.

[0100] In this embodiment of the application, four preset positions are set, and the relative distance between any preset position and the initial position is obtained respectively. Then, the current value of the cable under test is obtained according to each relative distance and the magnetic induction intensity corresponding to each preset position, so as to achieve accurate measurement of the current value of the cable under test.

[0101] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0102] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A current sensor, characterized in that, The current sensor includes: A magnetoresistive sensing unit is used to measure the magnetic flux density of the cable under test. A driving component, connected to the magnetoresistive sensing unit, is used to drive the magnetoresistive sensing unit to perform linear motion. The control module is connected to the magnetoresistive sensing unit and the driving component, respectively. It is used to control the driving component to drive the magnetoresistive sensing unit to move along a preset direction, and to obtain the magnetic induction intensity detected by the magnetoresistive sensing unit at multiple different preset positions, and to obtain the current value of the cable under test based on the magnetic induction intensity detected at multiple different preset positions.

2. The current sensor according to claim 1, characterized in that, The direction of motion of the magnetoresistive sensing unit is the same as the magnetic sensitivity direction of the magnetoresistive sensing unit.

3. The current sensor according to claim 1, characterized in that, The control module is further configured to control the driving component to drive the magnetoresistive sensing unit to move along a preset direction and to four different preset positions, respectively acquiring the relative distance between any preset position and the initial position, and the magnetic induction intensity of the magnetoresistive sensing unit at each preset position; wherein, The control module is also used to obtain the current value of the cable under test based on the relative distances and the magnetic induction intensities.

4. The current sensor according to claim 1, characterized in that, The current sensor also includes: The ranging module is connected to the control module and is arranged on the same straight line as the drive component and the magnetoresistive sensing unit. It is used to measure the position information of the magnetoresistive sensing unit at different preset positions. The control module is also used to acquire the magnetic induction intensity detected by the magnetoresistive sensing unit at each different preset position, acquire the relative distance between any preset position and the initial position according to the position information of the magnetoresistive sensing unit, and acquire the current value of the cable under test according to each relative distance and each magnetic induction intensity.

5. The current sensor according to claim 4, characterized in that, The ranging module includes a laser ranging module.

6. The current sensor according to claim 5, characterized in that, The relative distance between any two adjacent preset positions is the same.

7. The current sensor according to claim 1, characterized in that, The drive assembly includes a drive motor, a drive shaft, and a drive block disposed on the drive shaft. The magnetoresistive sensing unit is disposed on the drive block, and the drive motor is used to drive the drive block to move the magnetoresistive sensing unit along the drive shaft.

8. The current sensor according to claim 1, characterized in that, The current sensor is further provided with a sensing area for placing the cable under test, wherein the range of movement of the magnetoresistive sensing unit driven by the driving component along a preset direction is within the sensing range of the magnetoresistive sensing unit for detecting the magnetic induction intensity of the cable under test.

9. A current measurement method, characterized in that, The method includes: The control drive component drives the magnetoresistive sensing unit to move along a preset linear direction; The magnetic induction intensity detected by the magnetoresistive sensing unit at multiple different preset positions is obtained respectively; The current value of the cable under test is obtained based on each preset position and the corresponding detected magnetic induction intensity.

10. The current measurement method according to claim 9, characterized in that, The current value of the cable under test is obtained based on each preset position and the corresponding detected magnetic induction intensity, including: Set four different preset positions and obtain the relative distance between any preset position and the initial position; The current value of the cable under test is obtained based on the relative distances and the magnetic induction intensity corresponding to each preset position.

Images