Current sensor and current measuring method

Abstract

The invention relates to a current sensor and a current measuring method. The current sensor comprises a magnetic resistance sensing unit used for measuring the magnetic induction intensity of a cable to be measured; the driving assembly is connected with the magnetic resistance sensing unit and is used for driving the magnetic resistance sensing unit to do linear motion; the control module is connected with the magnetic resistance sensing unit and the driving assembly and used for controlling the driving assembly to drive the magnetic resistance sensing unit to move in the preset direction and correspondingly obtaining the magnetic induction intensity detected by the magnetic resistance sensing unit at multiple different preset positions. And the current value of the to-be-detected cable is obtained according to the magnetic induction intensities detected at the plurality of different preset positions. The current sensor adopted by the invention is simple in structure, low in cost and easy to install, the problem of inconsistency when the magnetic induction intensity of a plurality of different positions is detected by adopting a magnetic resistance sensing array can be avoided, and the accuracy of a detection result is improved.

Description

Technical Field

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

[0002] With the development of smart grids, higher requirements are placed on the perception and monitoring of electrical quantities. The commonly used data acquisition device is the 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 needs of the smart grid for comprehensive and real-time perception of information.

[0003] Traditional current sensors are equipped with multiple magnetoresistive sensing units to achieve current detection, but they are large in size and not convenient for universal installation. Summary of the invention

[0004] Based on this, it is necessary to provide a low-cost, small-sized and easy-to-install current sensor to address the above technical problems.

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

[0006] A magnetoresistive sensing unit, used to measure the magnetic induction intensity of the cable to be tested;

[0007] A driving component, connected to the magnetic resistance sensor unit, and used to drive the magnetic resistance sensor unit to perform linear motion;

[0008] The control module is connected to the magnetoresistive sensing unit and the driving component, respectively, and is used to control the driving component to drive the magnetoresistive sensing unit to move along a preset direction, and respectively obtain the magnetic induction intensity detected by the magnetoresistive sensing unit at multiple different preset positions, and obtain the current value of the cable to be tested according to the magnetic induction intensity detected at the multiple different preset positions.

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

[0010] In one embodiment, the control module is further used to control the driving component to drive the magnetic resistance sensor unit to move along a preset direction and to move 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 magnetic resistance sensor unit at each preset position; wherein,

[0011] The control module is also used to obtain the current value of the cable to be tested according to each of the relative distances and each of the magnetic induction intensities.

[0012] In one embodiment, the current sensor further includes:

[0013] A distance measuring module, connected to the control module and arranged on the same straight line with the driving component and the magnetic resistance sensing unit, for measuring the position information of the magnetic resistance sensing unit at different preset positions;

[0014] The control module is also used to respectively obtain the magnetic induction intensity detected by the magnetoresistive sensing unit at each different preset position, and to obtain the relative distance between any preset position and the initial position according to the position information of the magnetoresistive sensing unit, and to obtain the current value of the cable to be tested according to each relative distance and each magnetic induction intensity.

[0015] In one embodiment, the distance measurement module includes a laser distance measurement module.

[0016] In one embodiment, the relative distance between any two adjacent preset positions is the same.

[0017] In one embodiment, the driving assembly includes a driving motor, a driving shaft, and a driving block arranged on the driving shaft, the magnetic resistance sensor unit is arranged on the driving block, and the driving motor is used to drive the driving block to drive the magnetic resistance sensor unit to move along the driving shaft.

[0018] In one of the embodiments, the current sensor is further provided with a sensing area for placing the cable to be tested, wherein the moving range of the driving component driving the magnetoresistive sensing unit to move along a preset direction is within the sensing range of the magnetoresistive sensing unit detecting the magnetic induction intensity of the cable to be tested.

[0019] The above-mentioned current sensor includes a magnetoresistive sensing unit, a driving component and a control module, wherein the magnetoresistive unit measures the magnetic induction intensity of the cable to be tested, the driving component drives the magnetoresistive sensing unit to perform linear motion, the control module controls the driving component to drive the magnetoresistive sensing unit to move along a preset direction, and respectively obtains the magnetic induction intensity detected by the magnetoresistive sensing unit at multiple different preset positions, and the control module obtains the current value of the cable to be tested according to the magnetic induction intensity detected at multiple different preset positions, thereby realizing current measurement. Compared with the scheme in the related art that uses a magnetoresistive sensing array composed of multiple magnetoresistive sensing units to detect the magnetic induction intensity at multiple different positions, the present application can reduce the number of magnetoresistive sensing units, has a simple structure, low cost and is easy to install, and can also avoid the inconsistency problem existing when using a magnetoresistive sensing array to detect the magnetic induction intensity at multiple different positions, thereby improving the accuracy of the detection result.

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

[0021] Controlling the driving component to drive the magnetic resistance sensor unit to move along a preset straight line direction;

[0022] Respectively obtaining the magnetic induction intensities detected by the magnetoresistive sensing unit at a plurality of different preset positions;

[0023] The current value of the cable to be tested is obtained according to each of the preset positions and each of the corresponding detected magnetic induction intensities.

[0024] In one embodiment, obtaining the current value of the cable to be tested according to each of the preset positions and each of the corresponding detected magnetic induction intensities includes:

[0025] Set four different preset positions and obtain the relative distance between any preset position and the initial position respectively;

[0026] The current value of the cable to be tested is obtained according to each relative distance and the magnetic induction intensity corresponding to each preset position.

[0027] The above current measurement method controls the driving component to drive the magnetoresistive sensing unit to move along a preset straight line direction, respectively obtains the magnetic induction intensity detected by the magnetoresistive sensing unit at multiple different preset positions, and obtains the current value of the cable to be tested according to each preset position and each correspondingly detected magnetic induction intensity, thereby achieving the measurement of the current of the cable to be tested. This method avoids the error caused by the inconsistency of multiple magnetoresistive sensing units when using a magnetoresistive sensing array to detect the magnetic induction intensity at multiple different positions, thereby improving the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Output characteristic curves of multiple magnetoresistive sensing units of the same model;

[0029] Figure 2 is a structural block diagram of a current sensor in one embodiment;

[0030] Figure 3 is a block diagram of the internal structure of the magnetoresistive sensing unit;

[0031] Figure 4 A schematic diagram of a current sensor measuring a current of a current-carrying conductor in one embodiment;

[0032] Figure 5 is a structural block diagram of a current sensor in another embodiment;

[0033] Figure 6 is a structural block diagram of a driving component in one embodiment;

[0034] Figure 7 is a schematic flow chart of a current measurement method in one embodiment;

[0035] Figure 8FIG. 4 is a flow chart of a current measurement method in another embodiment.

[0036] Description of reference numerals:

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

[0038] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] In the related art, a Tunnel Magnetoresistance (TMR) cell array is generally used to measure current, wherein the TMR cell array includes a plurality of TMR cells at different positions.

[0040] When using a TMR cell array to measure current, usually only the relatively linear portion of its output characteristic curve is used. However, due to the errors caused by the manufacturing process, even the same model of TMR cells may have different output characteristics, that is, the output of the TMR array is inconsistent under the same magnetic field. Figure 1 The output characteristic curves of the same model of TMR unit. Under the same external magnetic field, the output voltage of the TMR unit is different, which will cause the measurement results of the magnetic field and current to deviate from the true value.

[0041] Based on this, the present application proposes a current sensor, such as Figure 2 As shown, the current sensor includes a magnetoresistive sensing unit 10, a driving component 20 and a control module 30. The driving component 20 is connected to the magnetoresistive sensing unit 10, and the control module 30 is connected to the magnetoresistive sensing unit 10 and the driving component 20 respectively.

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

[0043]

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

[0045] V o =kB+b

[0046] Among them, B is the magnetic induction intensity to be measured, k and b are the relevant parameters of the TMR unit output characteristics, k is the slope, and b is the straight line intercept. Based on this, within the range of the TMR unit, the magnetic induction intensity of the external magnetic field can be obtained according to the TMR unit output voltage.

[0047] The drive assembly 20 is used to drive the magnetic resistance sensor unit 10 to perform linear motion. The drive assembly 20 may include a drive motor such as a stepper motor and a rotary motor. Taking a stepper motor as an example, the rotor of the stepper 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 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 a certain angle, the rotor will rotate a certain angle with the magnetic field. In this way, every time an electric pulse is input, the rotor will rotate a certain angle and move forward. By changing the order in which the windings are energized, the stepper motor will reverse. The rotation of the stepper motor can be controlled by controlling the number of pulses, the frequency, and the order in which the windings are energized, so that the magnetic resistance sensor unit 10 can be driven to move.

[0048] The control module 30 can be used to control the driving component 20 to drive the magnetic resistance sensing unit 10 to move along a preset direction, and respectively obtain the magnetic induction intensity detected by the magnetic resistance sensing unit 10 at multiple different preset positions, and obtain the current value of the cable to be tested according to the magnetic induction intensity detected at multiple different preset positions. The control module 30 can be integrated with the driving component 20 at the local end, or it can be a computer device, such as a server, a computer, a mobile phone, a tablet computer, etc.

[0049] Specifically, the control module 30 sends a control instruction to the drive component 20, and the control instruction includes controlling the number of pulses, the pulse frequency, and the power-on sequence of the motor windings, so that the drive component 20 drives the magnetic resistance sensor unit to move linearly along a preset direction, thereby moving to different preset positions in sequence. Then the control module 30 respectively obtains the magnetic induction intensity detected by the magnetic resistance sensor unit at multiple preset positions, and further calculates the current value of the cable to be tested based on the multiple magnetic induction intensity data.

[0050] In the embodiment of the present application, the current sensor includes a magnetoresistive sensing unit 10, a driving component 20 and a control module 30, wherein the magnetoresistive unit measures the magnetic induction intensity of the cable to be tested, the driving component 20 drives the magnetoresistive sensing unit 10 to perform linear motion, and the control module 30 controls the driving component 20 to drive the magnetoresistive sensing unit 10 to move along a preset direction, and respectively obtains the magnetic induction intensity detected by the magnetoresistive sensing unit 10 at multiple different preset positions, and the control module 30 obtains the current value of the cable to be tested according to the magnetic induction intensity detected at multiple different preset positions, thereby realizing current measurement. Compared with the scheme of using a magnetoresistive sensing array composed of multiple magnetoresistive sensing units to detect the magnetic induction intensity at multiple different positions in the related art, the present application can reduce the number of magnetoresistive sensing units, has a simple structure, low cost and is easy to install, and can also avoid the inconsistency problem existing when using a magnetoresistive sensing array to detect the magnetic induction intensity at multiple different positions, thereby improving the accuracy of the detection result.

[0051] In one embodiment, the current sensor is provided with a sensing area for placing the cable to be tested, wherein the moving range of the driving component 20 driving the magnetoresistive sensing unit 10 to move along the preset direction is located within the sensing range of the magnetoresistive sensing unit 10 detecting the magnetic induction intensity of the cable to be tested, thereby ensuring that when measuring the cable current, the magnetoresistive sensing unit 10 can detect the magnetic induction intensity of the cable to be tested at each preset position.

[0052] In one embodiment, the movement direction 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 in this specific direction, a smaller magnetic field is required for the magnetoresistive magnetization to reach a saturation state. Figure 4 As shown, H represents the magnetic sensitive 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 sensitive direction. Therefore, when measuring the current, it is necessary to ensure that the movement direction of the magnetoresistive sensing unit 10 is in a straight line with the magnetic sensitive direction of the magnetoresistive sensing unit 10, so that the magnetic sensitive direction of the magnetoresistive sensing unit 10 at each preset position is parallel to the external magnetic field, thereby improving the accuracy and sensitivity of the magnetoresistive sensing unit 10 in measuring the magnetic induction intensity.

[0053] In one embodiment, the control module 30 is also used to control the driving component 20 to drive the magnetoresistive sensor unit 10 to move along a preset direction and to move 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 sensor unit 10 at each preset position.

[0054] For example, Figure 4As shown, four preset positions L1, L2, L3, and L4 can be set, and the four preset positions are on a straight line, and the preset position L1 is used as the initial position of the magnetic resistance sensor unit 10. The relative distances between L2, L3, and L4 and the initial position L1 are set in advance in the control module 30 as m, n, and k, respectively. Further, the control module 30 controls the drive component 20 to drive the magnetic resistance sensor unit 10 to move a corresponding distance by changing the number of control pulses sent to the drive component 20.

[0055] The control module 30 is also used to obtain the current value of the cable to be tested according to each relative distance and each magnetic induction intensity. Taking the current of the current-carrying wire as an example, the principle of the control module 30 of the present application obtaining the current value of the cable to be tested according to each relative distance and each magnetic induction intensity is explained. Figure 4 In the example, assume that the current in the current-carrying wire is I x , B0 is the component of the external interference magnetic field in the magnetic sensitive direction of the magnetoresistive sensing unit 10; B1, B2, B3, B4 are the magnetic induction intensities measured by the magnetoresistive sensing unit 10 at four preset positions; x1, x2, x3, x4 are the distances from the magnetoresistive sensing unit 10 to the current-carrying wire at the four preset positions; assuming that the common perpendicular line segment between the current-carrying wire and the straight line at the four preset positions is d, and the plane passing through the straight line at the four preset positions and perpendicular to the perpendicular line segment d is s, θ1, θ2, θ3, θ4 are the angles between the perpendicular line from the magnetoresistive sensing unit 10 to the current-carrying wire and the plane s when the magnetoresistive 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 at the four preset positions is α. Let

[0056]

[0057] Where μ0 is the vacuum magnetic permeability, according to the Biot-Savart law:

[0058]

[0059] according to Figure 4 The spatial geometric relationship between the preset positions and the current-carrying wires shown in can be obtained:

[0060]

[0061] Among them, B1, B2, B3, B4, m, n, k are known quantities.

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

[0063] Arranging formula (2) and (3) yields:

[0064] 0 = ax4 +bx 3 +cx 2 +dx+e (4)

[0065] For ease of expression, 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 just an intermediate quantity set in the calculation process to conveniently represent the values ​​of a, b, c, d, and e. Its specific value is:

[0068]

[0069] Substitute formula (6) into formula (5) to obtain the values ​​of a, b, c, d, and e, and then substitute them into formula (4) to obtain

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

[0071] Then there is

[0072] According to formula (2)(3)(7), we can get

[0073]

[0074] According to the above formulas (1) to (8), the current I is obtained

[0075]

[0076] The final current value of the current-carrying wire is

[0077]

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

[0079] In the embodiment of the present application, the control module 30 controls the driving component 20 to drive the magnetoresistive sensing unit 10 to move along a straight line in the magnetically sensitive direction of the magnetoresistive sensing unit 10, and move to four preset positions, with the first preset position being used as the initial position; then the control module 30 respectively obtains the relative distance between any preset position and the initial position and the magnetic induction intensity measured by the magnetoresistive sensing unit 10 at each preset position, and further, calculates the current value of the cable to be tested based on each relative distance and each magnetic induction intensity, thereby achieving accurate measurement of the current.

[0080] In one embodiment, in order to reduce computational complexity, the relative distances between any two adjacent preset positions may be set to be the same.

[0081] In one embodiment, the current sensor further includes a distance measurement module. Figure 5 As shown, the distance measuring module 40 is connected to the control module 30, and is arranged on the same straight line with the driving component 20 and the magnetoresistive sensing unit 10, and is used to measure the position information of the magnetoresistive sensing unit 10 at different preset positions. Further, the control module 30 is also used to respectively obtain the magnetic induction intensity detected by the magnetoresistive sensing unit 10 at each different preset position, and obtain the relative distance between any preset position and the initial position according to the position information of the magnetoresistive sensing unit 10, and obtain the current value of the cable to be tested according to each relative distance and each magnetic induction intensity.

[0082] In the embodiment of the present application, the displacement accuracy of the driving component 20 itself is at the micron level, which can meet most application scenarios. However, when the current sensor is used in a scenario with higher displacement accuracy, a distance measurement module 40 is required to position the magnetoresistive sensing unit 10 so that the magnetoresistive sensing unit 10 can reach the preset position more accurately, and send the position information of the magnetoresistive sensing unit 10 to the control module 30. The distance measurement module 40 can be a high-precision laser distance measurement module and a nanometer displacement meter, etc.

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

[0084] In the embodiment of the present application, the magnetoresistive sensor unit 10 is precisely positioned by setting a distance measuring module 40 so that it can accurately reach a preset position, and the position information of the magnetoresistive sensor 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 according to the position information, and calculate the current value based on each relative distance and the magnetic induction intensity detected at each preset position, thereby improving the accuracy of the measured current value.

[0085] In one embodiment, Figure 6As shown, the drive assembly 20 includes a drive motor 201, a drive shaft 202, and a drive block 203 disposed on the drive shaft, and the magnetic resistance sensor unit 10 is disposed on the drive block 203. The drive assembly 20 drives the magnetic resistance sensor unit 10 to move along the drive shaft 202 through the drive block 203. Exemplarily, the drive assembly 20 can adopt an externally driven linear stepper motor. The lead screw and the motor rotor of the externally driven linear stepper motor are integrated as the output shaft of the motor, and a drive block is disposed on the lead screw. When the motor is working, the output shaft rotates, so that the drive block can move back and forth on the output shaft, thereby causing the magnetic resistance sensor unit 10 to move linearly along the output shaft.

[0086] In an embodiment of the present application, the driving assembly includes a driving motor, a driving shaft and a driving block arranged on the driving shaft. The driving motor operates to rotate the driving shaft, and the driving block moves back and forth as the driving shaft rotates, so that the magnetoresistive sensor unit moves linearly along the driving shaft to measure the magnetic induction intensity at multiple preset positions, thereby avoiding the error caused by the inconsistency of multiple magnetoresistive sensor units when measuring current using a magnetoresistive sensor array, thereby improving the measurement accuracy.

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

[0088] Step 702: Control the driving component to drive the magnetic resistance sensor unit to move along a preset straight line direction.

[0089] The control module in the current sensor can send control instructions to the drive component, which include the number of control pulses, pulse frequency, and the power-on sequence of the motor winding, so that the drive component drives the magnetic resistance sensor unit to move linearly along a preset direction, including forward and backward along a straight line. The preset straight line direction is the straight line where the drive shaft of the drive component is located, and the straight line is collinear with the magnetic sensitivity direction of the magnetic resistance sensor unit.

[0090] Step 704 , respectively obtaining the magnetic induction intensities detected by the magnetoresistive sensor unit at a plurality of different preset positions.

[0091] A plurality of preset positions are set, and the plurality of preset positions are collinear. When the control module controls the driving component to drive the magnetic resistance sensor unit to move to each preset position, the control module obtains the magnetic induction intensity detected by the magnetic resistance sensor unit at the preset position.

[0092] Step 706: Obtain the current value of the cable to be tested according to each preset position and each corresponding detected magnetic induction intensity.

[0093] The control module calculates the current value of the cable to be tested according to the magnetic induction intensity detected by the magnetic resistance sensor unit at each preset position.

[0094] In the embodiment of the present application, the current sensor controls the driving component to drive the magnetoresistive sensing unit to move along the preset straight line direction, and the magnetic induction intensity detected by the magnetoresistive sensing unit at multiple different preset positions is respectively obtained, and the current value of the cable to be tested is obtained according to each preset position and each correspondingly detected magnetic induction intensity, thereby realizing the measurement of the current of the cable to be tested. In addition, the use of the current sensor to measure the current avoids the error caused by the inconsistency of multiple magnetoresistive sensing units when the magnetoresistive sensing array is used to measure the magnetic induction intensity, thereby improving the measurement accuracy.

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

[0096] Step 802, setting four different preset positions, and obtaining the relative distance between any preset position and the initial position respectively.

[0097] Four preset positions are set, and the first preset position is used as the initial position of the magnetoresistive sensing unit. The relative distance between any preset position and the initial position can be set in advance in the control module. The control module controls the drive component to drive the magnetoresistive sensing unit to move to the preset positions in sequence along the preset direction. In the embodiment of the present application, the displacement accuracy of the drive component of the current sensor to drive the magnetoresistive sensing unit to move can reach the micron level, which can meet most application scenarios.

[0098] Step 804, obtaining the current value of the cable to be tested according to each relative distance and the magnetic induction intensity corresponding to each preset position.

[0099] The control module calculates the current value of the cable to be tested using formulas (1) to (9) according to the acquired relative distance and the magnetic induction intensity collected by the magnetic resistance sensor unit.

[0100] In an embodiment of the present application, by setting four preset positions, and obtaining the relative distances between any preset positions and the initial position respectively, and then obtaining the current value of the cable to be tested based on each relative distance and the magnetic induction intensity corresponding to each preset position, accurate measurement of the current value of the cable to be tested is achieved.

[0101] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A current sensor, characterized in that: The current sensor comprises: A magnetoresistive sensing unit, used to measure the magnetic induction intensity of the cable to be tested; A driving component, connected to the magnetic resistance sensor unit, and used to drive the magnetic resistance sensor unit to perform linear motion; The control module is connected to the magnetoresistive sensing unit and the driving component, respectively, and is used to control the driving component to drive the magnetoresistive sensing unit to move along a preset direction, and respectively obtain the magnetic induction intensity detected by the magnetoresistive sensing unit at multiple different preset positions, and obtain the current value of the cable to be tested according to the magnetic induction intensity detected at the multiple different preset positions.

2. The current sensor according to claim 1, characterized in that: The movement direction 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 also used to control the driving component to drive the magnetic resistance sensor unit to move along a preset direction and to move 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 magnetic resistance sensor unit at each preset position; wherein, The control module is also used to obtain the current value of the cable to be tested according to each of the relative distances and each of the magnetic induction intensities.

4. The current sensor according to claim 1, characterized in that: The current sensor also includes: A distance measuring module, connected to the control module and arranged on the same straight line with the driving component and the magnetic resistance sensing unit, for measuring the position information of the magnetic resistance sensing unit at different preset positions; The control module is also used to respectively obtain the magnetic induction intensity detected by the magnetoresistive sensing unit at each different preset position, and to obtain the relative distance between any preset position and the initial position according to the position information of the magnetoresistive sensing unit, and to obtain the current value of the cable to be tested according to each relative distance and each magnetic induction intensity.

5. The current sensor according to claim 4, characterized in that: The distance measurement module includes a laser distance measurement 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 driving assembly includes a driving motor, a driving shaft, and a driving block arranged on the driving shaft. The magnetic resistance sensor unit is arranged on the driving block. The driving motor is used to drive the driving block to drive the magnetic resistance sensor unit to move along the driving shaft.

8. The current sensor according to claim 1, characterized in that: The current sensor is also provided with a sensing area for placing the cable to be tested, wherein the moving range of the driving component driving the magnetoresistive sensing unit to move along a preset direction is within the sensing range of the magnetoresistive sensing unit detecting the magnetic induction intensity of the cable to be tested.

9. A current measurement method, characterized in that: The method comprises: Controlling the driving component to drive the magnetic resistance sensor unit to move along a preset straight line direction; Respectively obtaining the magnetic induction intensities detected by the magnetoresistive sensing unit at a plurality of different preset positions; The current value of the cable to be tested is obtained according to each of the preset positions and each of the corresponding detected magnetic induction intensities.

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

Images