CN110940842A - Follower current measuring device and method based on tunnel magnetoresistive chip - Google Patents
Follower current measuring device and method based on tunnel magnetoresistive chip Download PDFInfo
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- CN110940842A CN110940842A CN201911182678.5A CN201911182678A CN110940842A CN 110940842 A CN110940842 A CN 110940842A CN 201911182678 A CN201911182678 A CN 201911182678A CN 110940842 A CN110940842 A CN 110940842A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
- G01R15/205—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices using magneto-resistance devices, e.g. field plates
Abstract
The invention discloses a device and a method for measuring follower current based on a tunnel magnetoresistive chip, wherein the device comprises: a V-shaped groove member and a U-shaped groove member; the U-shaped groove component comprises a linear displacement sensor and a tunnel magnetic resistance chip; the groove sections of the U-shaped groove component and the V-shaped groove component are bilaterally symmetrical along the central axis; the groove of the U-shaped groove component is opposite to the groove of the V-shaped groove component; the symmetry axis of the groove section of the U-shaped groove component coincides with the symmetry axis of the groove section of the V-shaped groove component; the displacement direction of the linear displacement sensor is coincided with the symmetry axis; the tunnel magnetic resistance chip is arranged at the top of the linear displacement sensor and is vertical to the symmetry axis; during measurement, an electrified lead to be measured is placed between the V-shaped groove component and the U-shaped groove component which are oppositely placed, and is fastened and fixed through the linear displacement sensor and the V-shaped groove; the current direction of the electrified lead and the magnetic field sensitive direction marked on the tunnel magnetoresistive chip follow the ampere rule.
Description
Technical Field
The invention relates to the technical field of electric power, in particular to a follower current measuring device and method based on a tunnel magnetoresistive chip.
Background
The current is the basic measurement subject of energy consumption monitoring. Currently, current sensors perform current measurement based on several physical principles. Firstly, the current divider (shunt) based on ohm's law, the output voltage at two ends of the current divider is in direct proportion to the current to be measured, has the advantages of low cost and convenient application, can meet the current measurement application of general requirements, and is still widely used at present. However, the shunt is connected in series in the circuit, so that the limitation is obvious: the loss is large when measuring large current, and no electric insulation exists. Therefore, when the device is used in an environment requiring electrical insulation, additional electrical insulation measures, such as an isolation amplifier, are required, which results in increased cost and reduced bandwidth. And secondly, the current sensor based on the ampere loop law indirectly measures the magnitude and the direction of current by measuring a magnetic field and has the electrical insulation of an original side and a secondary side. Current sensors for industrial applications are generally based on the following 5 measurement techniques: HALL (HALL) current sensors; a fluxgate (fluxgate) current sensor; magnetoresistive (MR) current sensors including Anisotropic Magnetoresistance (AMR), Giant Magnetoresistance (GMR), Tunnel Magnetoresistance (TMR); rogowski coil (Rogowski coil) and current transformer (current transformer). There are other indirect measurement techniques of current sensors. The indirect measurement of the current is realized mainly by combining a magnetic field with other physical principles or effects. Including faraday-effect magneto-optical effect (faraday-optical), nuclear magnetic resonance NMR (nuclear-resonance), magnetostrictive effect (magnetostrictive effect), quantum hall effect (quantumhall effect), superconducting quantum interference device SQUID, etc. The technologies and products thereof have different characteristics aiming at different market segments. For example, current sensors based on NMR, quantum hall effect and SQUID have high requirements on application environment and high price, and are applied to laboratory instruments in small quantities, so far, part of the technology is still immature and is in the development or perfection stage; the current sensor based on the Faraday magneto-optical effect has better performance in measuring alternating current large current (such as 100kA), but the performance problem needs to be solved urgently when measuring direct current.
The state perception is extended to the internal energy utilization equipment of the client through the random measurement, rich energy production, consumption and degradation operation data can be collected through the wide access of the random equipment, and the ubiquitous power internet of things with comprehensive state perception, efficient information processing and intelligent energy utilization is created. However, the current measurement method is mostly based on a mutual inductor form, the volume is generally large, and the requirements of small volume, wide deployment, low cost and the like of measurement along with a device cannot be met.
Disclosure of Invention
In order to solve the problems that the existing current measuring method in the background technology has larger measuring volume and can not meet the measuring requirement of a follower, the invention provides a follower current measuring device and method based on a tunnel magnetoresistive chip; the device and the method do not need a mutual inductor to measure the current; monitoring the magnetic field characteristics near the electrified lead through a tunnel magnetic resistance chip, and calculating the current magnitude; the follower current measuring device based on the tunnel magnetoresistive chip comprises:
a V-shaped groove member and a U-shaped groove member; the U-shaped groove component comprises a linear displacement sensor and a tunnel magnetic resistance chip;
the groove section of the U-shaped groove component is bilaterally symmetrical along the central axis; the groove section of the V-shaped groove component is bilaterally symmetrical along the central axis;
the groove of the U-shaped groove component is opposite to the groove of the V-shaped groove component; the symmetry axis of the groove section of the U-shaped groove component is superposed with the symmetry axis of the groove section of the V-shaped groove component;
the linear displacement sensor is arranged at the intersection position of the cross section of the U-shaped groove and the symmetry axis, and the displacement direction of the linear displacement sensor is superposed with the symmetry axis;
the tunnel magnetic resistance chip is arranged at the top of the linear displacement sensor and is vertical to the symmetry axis;
during measurement, an electrified lead to be measured is placed between the V-shaped groove component and the U-shaped groove component which are oppositely placed, and is fastened and fixed through the linear displacement sensor and the V-shaped groove; the current direction of the electrified lead and the magnetic field sensitive direction marked on the tunnel magnetoresistive chip follow the ampere rule.
Further, one side of the groove of the U-shaped groove component is hinged with one side of the groove of the V-shaped groove component and can rotate along the direction vertical to the section of the groove;
the other side of the groove of the U-shaped groove component is connected with one side of the groove of the V-shaped groove component through a buckle.
Further, the tunnel magnetic resistance chip is arranged on the top of the linear displacement sensor, and includes:
a magnetic sensitive probe is arranged at the top of the linear displacement sensor; the material of the magnetic sensitive probe comprises flame-retardant plastic;
and the tunnel magnetic resistance chip is attached to the PCB and packaged into the magnetic sensitive probe, so that the tunnel magnetic resistance chip is perpendicular to the symmetry axis.
Further, the apparatus further comprises a computing unit;
the linear displacement sensor is used for acquiring the linear displacement of the sensor after the device is placed in a to-be-tested electrified lead; the output end of the linear displacement sensor is connected with the input end of the computing unit;
the tunnel magnetic resistance chip is used for acquiring an analog differential signal influenced by the magnetic field intensity; the output end of the tunnel magnetic resistance chip is connected with the input end of the computing unit;
and the calculation unit is used for calculating and obtaining the current value of the electrified lead to be measured according to the linear displacement and the analog differential signal.
Further, the calculating unit is configured to calculate and obtain a magnetic field strength according to the received analog differential signal;
the computing unit is used for computing and obtaining the distance between the tunnel magnetoresistive chip and the center of the wire according to the received linear displacement;
the calculation unit is used for calculating and obtaining the current value of the electrified lead to be tested according to the magnetic field intensity and the distance between the tunnel magnetic resistance chip and the center of the lead.
Further, when the angle of the V-shaped angle of the groove section of the V-groove part is 90 degrees; the current I is calculated in the following way:
wherein, mu0Is the magnetic permeability of air; h is the linear displacement, namely the distance moved by the linear displacement sensor with the vertex of the V-shaped angle as a starting point during measurement; b is the magnetic field intensity.
Furthermore, gradienters are respectively arranged on the surfaces of the V-shaped groove component and the U-shaped groove component; the two gradienters are parallel when the V-shaped groove part and the U-shaped groove part are oppositely arranged;
elastic buffer materials are arranged on the contact surfaces of the V-shaped groove component and the U-shaped groove component when the V-shaped groove component and the U-shaped groove component are oppositely arranged;
the buckle connected with the V-shaped groove component and the U-shaped groove component comprises a locking component capable of adjusting tightness;
before measurement, the readings of the two levels are adjusted to remain the same by adjusting the locking member.
The follower current measuring method based on the tunnel magnetoresistive chip comprises the following steps:
placing an electrified lead to be measured between the V-shaped groove component and the U-shaped groove component which are oppositely placed, and fastening and fixing the electrified lead through a linear displacement sensor and the V-shaped groove;
acquiring linear displacement through a linear displacement sensor;
acquiring an analog differential signal influenced by the magnetic field intensity through a tunnel magnetoresistive chip;
and calculating to obtain the current value of the electrified lead to be tested according to the linear displacement and the analog differential signal.
Further, the calculating the current value of the to-be-measured electrified lead according to the linear displacement and the analog differential signal includes:
calculating to obtain the magnetic field intensity according to the received analog differential signal;
calculating the distance from the tunnel magnetoresistive chip to the center of the wire according to the received linear displacement;
and calculating to obtain the current value of the electrified lead to be tested according to the magnetic field intensity and the distance between the tunnel magnetic resistance chip and the center of the lead.
Further, when the angle of the V-shaped angle of the groove section of the V-groove part is 90 degrees; the current I is calculated in the following way:
wherein, mu0Is the magnetic permeability of air; h is the linear displacement, namely the distance moved by the linear displacement sensor with the vertex of the V-shaped angle as a starting point during measurement; b is the magnetic field intensity.
The invention has the beneficial effects that: the technical scheme of the invention provides a device and a method for measuring current of a follower based on a tunnel magnetoresistive chip, wherein the device and the method do not need a mutual inductor to measure the current; monitoring the magnetic field characteristics near the electrified lead through a tunnel magnetic resistance chip, and calculating the current magnitude; the device and the method fully utilize the characteristics of high sensitivity, low power consumption, low background noise, wide dynamic range and low magnetic hysteresis of the tunnel magnetoresistive chip, and meet the high-precision miniaturized design requirement of the current sensor for measuring the random. The device and the method realize the fine management of the power consumption of different electrical appliances by measuring the current of the electrical appliances, and lay a strong foundation for energy conservation and consumption reduction.
Drawings
A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:
FIG. 1 is a structural diagram of a follower current measuring device based on a tunneling magneto-resistive chip according to an embodiment of the present invention;
fig. 2 is a flowchart of a follower current measuring method based on a tunneling magneto-resistive chip according to an embodiment of the present invention.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
FIG. 1 is a structural diagram of a follower current measuring device based on a tunneling magneto-resistive chip according to an embodiment of the present invention; as shown in fig. 1, the apparatus includes:
a V-groove part 120 and a U-groove part 110; the U-shaped groove part 110 comprises a linear displacement sensor 111 and a tunnel magnetic resistance chip 112;
the groove section of the U-shaped groove part 110 is bilaterally symmetrical along the central axis; the groove section of the V-shaped groove part 120 is bilaterally symmetrical along the central axis;
as shown in fig. 1, in the present embodiment, the groove section of the U-shaped groove component 110 is a semicircle, and a connection line between a highest point of the semicircle and a center of the semicircle is on the central axis; but the groove section not only comprises a semicircle, but also comprises a U-shaped groove section which is symmetrical left and right and has other shapes;
the groove section of the V-shaped groove part 120 is an isosceles triangle, and particularly, the isosceles triangle may be an equilateral triangle or an isosceles right triangle for convenience of calculation; in this embodiment, the cross section of the groove is preferably selected to be an isosceles right triangle, and the lowest point of the groove is a right angle;
the opposing placement of the groove of the U-shaped groove part 110 and the groove of the V-shaped groove part 120; the symmetry axis of the groove section of the U-shaped groove part 110 coincides with the symmetry axis of the groove section of the V-shaped groove part 120;
the relative placement in this embodiment refers to the manner shown in fig. 1, that is, the slots and the slots are opposite to each other, so as to form a space region, which is a U-shaped space and a V-shaped space, and is used for placing the to-be-tested power-on wires;
when the electrified conducting wire to be tested is placed in the space area, the highest point of the section of the U-shaped groove, the circle center of the semicircle where the section of the U-shaped groove is located (or the corresponding position of the sections of other grooves), the circle center of the section of the electrified conducting wire and the lowest point of the section of the V-shaped groove are located on the same straight line and the symmetry axis.
The linear displacement sensor 111 is arranged at the intersection position of the cross section of the U-shaped groove and the symmetry axis, and the displacement direction of the linear displacement sensor 111 is superposed with the symmetry axis;
the tunnel magnetoresistive chip 112 is arranged at the top of the linear displacement sensor 111 and is perpendicular to the symmetry axis;
as shown in fig. 1, in the present embodiment, the linear vertical sensor is a sliding resistance type linear displacement sensor 111, and detects a sensor displacement distance; the displacement direction of the linear displacement sensor 111 coincides with the symmetry axis, that is, the linear displacement sensor 111 moves on the symmetry axis;
a magnetic sensitive probe is arranged at the top of the linear displacement sensor 111; the magnetic sensitive probe can be made of flame-retardant plastic; furthermore, the surfaces of the U-shaped groove part 110 and the V-shaped groove part 120, which are in contact with the to-be-measured electrified lead, can be made of flame-retardant plastic, so as to ensure the safety during measurement.
And the tunnel magnetic resistance chip 112 is attached to the PCB and packaged into the magnetic sensitive probe, so that the tunnel magnetic resistance chip 112 is ensured to be vertical to the symmetry axis. The tunnel magnetoresistive chip 112 is of a patch-shaped structure, and the direction perpendicular to the symmetry axis means that when the tunnel magnetoresistive chip 112 is abstracted into a plane, the plane is perpendicular to the symmetry axis, so that the magnetic field cutting effect is best when measuring an electrified lead;
in addition, since the tunnel magnetoresistance chip 112 is marked with a magnetic field sensitive direction, when the tunnel magnetoresistance chip 112 is packaged, attention should be paid to the packaging direction to ensure that the magnetic field sensitive direction of the tunnel magnetoresistance chip 112 and the magnetic field direction of the magnetic field formed by the to-be-tested power-on wire under the ampere rule can be consistent.
Further, one side of the groove of the U-shaped groove part 110 is hinged to one side of the groove of the V-shaped groove part 120 and can rotate in a direction perpendicular to the groove section; the other side of the groove of the U-shaped groove part 110 is connected to one side of the groove of the V-shaped groove part 120 by a snap.
In this embodiment, in order to ensure that the position of the energized conductor is relatively fixed during measurement, the U-shaped groove member 110 and the V-shaped groove member 120 may be fastened by the above-mentioned connection manner; in the present embodiment, only one connection method is provided, but it should be noted that other methods that can fixedly connect the U-shaped groove part 110 and the V-shaped groove part 120 and relatively fix the positions of the current-carrying wires can be applied to the present apparatus.
Further, in order to improve the accuracy and sensitivity of the present apparatus, the symmetry axes of the V-groove part 120 and the U-groove part 110 should be kept coincident during measurement; accordingly, a level is provided on each of the surfaces of the V-groove member 120 and the U-groove member 110; the two levels are parallel to each other when the V-shaped groove part 120 and the U-shaped groove part 110 are placed opposite to each other; when the two levels are in the same horizontal state, the symmetry axes of the V-shaped groove part 120 and the U-shaped groove part 110 are at least parallel, and since the relative positions of the V-shaped groove part 120 and the U-shaped groove part 110 in the transverse direction are fixed in the above-described connection manner, the two symmetry axes coincide when the symmetry axes of the V-shaped groove part 120 and the U-shaped groove part 110 are parallel.
In order to ensure that the horizontal state of the V-shaped groove component 120 and the U-shaped groove component 110 can be relatively adjusted, elastic buffer materials are arranged on the contact surfaces when the V-shaped groove component 120 and the U-shaped groove component 110 are oppositely placed; the buckle connected with the V-shaped groove part 120 and the U-shaped groove part 110 comprises a locking part with adjustable tightness; before measurement, the readings of the two levels are adjusted to remain the same by adjusting the locking member.
In this embodiment, the locking component may be a fastener with a limiting function, such as a bolt and a nut.
During measurement, an electrified lead to be measured is placed between the V-shaped groove component 120 and the U-shaped groove component 110 which are oppositely placed, and is fastened and fixed through the linear displacement sensor 111 and the V-shaped groove; the current direction of the electrified lead and the magnetic field sensitive direction marked on the tunnel magnetic resistance chip 112 follow the ampere rule.
Further, the apparatus further comprises a computing unit;
the linear displacement sensor 111 is used for acquiring the linear displacement of the sensor after the device is placed in a to-be-tested electrified lead; the output end of the linear displacement sensor 111 is connected with the input end of the computing unit;
the tunnel magnetoresistive chip 112 is used for acquiring an analog differential signal influenced by the magnetic field intensity; the output end of the tunnel magnetoresistive chip 112 is connected with the input end of the computing unit;
and the calculation unit is used for calculating and obtaining the current value of the electrified lead to be measured according to the linear displacement and the analog differential signal.
Specifically, the calculating unit is configured to calculate and obtain the magnetic field strength according to the received analog differential signal; the V + pin and the V-pin of the tunnel magnetoresistance chip 112 output analog differential signals, and the analog differential signals have a linear relationship with the magnitude of the magnetic field of the tunnel magnetoresistance chip 112, so that the magnetic field strength value can be obtained by simulating the differential signals through preset proportional parameters.
The computing unit is used for computing and obtaining the distance between the tunnel magnetoresistive chip 112 and the center of the wire according to the received linear displacement; when the to-be-tested power-on lead is not placed in the device, the linear displacement sensor 111 may be located at the lowest end of the cross section of the V-shaped groove component 120, and when the to-be-tested power-on lead is placed in the device, an example of movement of the linear displacement sensor 111 is an example of calculating a distance from the required tunnel magnetoresistive chip 112 to the center of the lead; if the linear displacement sensor 111 is not located at the lowest end position of the cross section of the V-shaped groove component 120 when the to-be-tested power-on lead is not placed in the device, the location should be determined, and the distance from the tunnel magnetoresistive chip 112 to the center of the lead can still be calculated and obtained through the moving distance and the original location of the linear displacement sensor
The calculation unit is used for calculating and obtaining the current value of the electrified lead to be tested according to the magnetic field intensity and the distance between the tunnel magnetic resistance chip 112 and the center of the lead.
It can be known that the calculation method of the current I to the county is as follows:
I＝2πr*μ0*B
in the present embodiment, only the calculation is exemplified when the angle of the V-shaped angle of the groove cross section of the V-groove member 120 is 90 degrees: the current I is calculated in the following way:
wherein, mu0Is the magnetic permeability of air; h is the linear displacement amount, that is, the distance moved by the linear displacement sensor 111 when measuring, with the vertex of the V-shaped angle as the starting point; r is the wire diameter of the wire; b is the magnetic field intensity.
Fig. 2 is a flowchart of a follower current measuring method based on a tunneling magneto-resistive chip according to an embodiment of the present invention, as shown in fig. 2, the method includes:
and 240, calculating to obtain the current value of the electrified lead to be tested according to the linear displacement and the analog differential signal.
Further, the calculating the current value of the to-be-measured electrified lead according to the linear displacement and the analog differential signal includes:
calculating to obtain the magnetic field intensity according to the received analog differential signal;
calculating the distance from the tunnel magnetoresistive chip to the center of the wire according to the received linear displacement;
and calculating to obtain the current value of the electrified lead to be tested according to the magnetic field intensity and the distance between the tunnel magnetic resistance chip and the center of the lead.
Further, when the angle of the V-shaped angle of the groove section of the V-groove part is 90 degrees; the current I is calculated in the following way:
wherein, mu0Is the magnetic permeability of air; h is the linear displacement, namely the distance moved by the linear displacement sensor with the vertex of the V-shaped angle as a starting point during measurement; b is the magnetic field intensity.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the disclosure may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Reference to step numbers in this specification is only for distinguishing between steps and is not intended to limit the temporal or logical relationship between steps, which includes all possible scenarios unless the context clearly dictates otherwise.
Moreover, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the disclosure and form different embodiments. For example, any of the embodiments claimed in the claims can be used in any combination.
Various component embodiments of the disclosure may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. The present disclosure may also be embodied as device or system programs (e.g., computer programs and computer program products) for performing a portion or all of the methods described herein. Such programs implementing the present disclosure may be stored on a computer-readable medium or may be in the form of one or more signals. Such a signal may be downloaded from an internet website or provided on a carrier signal or in any other form.
It should be noted that the above-mentioned embodiments illustrate rather than limit the disclosure, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The disclosure may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several systems, several of these systems may be embodied by one and the same item of hardware.
The foregoing is directed to embodiments of the present disclosure, and it is noted that numerous improvements, modifications, and variations may be made by those skilled in the art without departing from the spirit of the disclosure, and that such improvements, modifications, and variations are considered to be within the scope of the present disclosure.
Claims (10)
1. A tunneling magnetoresistive chip-based follower current measurement apparatus, the apparatus comprising: a V-shaped groove member and a U-shaped groove member; the U-shaped groove component comprises a linear displacement sensor and a tunnel magnetic resistance chip;
the groove section of the U-shaped groove component is bilaterally symmetrical along the central axis; the groove section of the V-shaped groove component is bilaterally symmetrical along the central axis;
the groove of the U-shaped groove component is opposite to the groove of the V-shaped groove component; the symmetry axis of the groove section of the U-shaped groove component is superposed with the symmetry axis of the groove section of the V-shaped groove component;
the linear displacement sensor is arranged at the intersection position of the cross section of the U-shaped groove and the symmetry axis, and the displacement direction of the linear displacement sensor is superposed with the symmetry axis;
the tunnel magnetic resistance chip is arranged at the top of the linear displacement sensor and is vertical to the symmetry axis;
during measurement, an electrified lead to be measured is placed between the V-shaped groove component and the U-shaped groove component which are oppositely placed, and is fastened and fixed through the linear displacement sensor and the V-shaped groove; the current direction of the electrified lead and the magnetic field sensitive direction marked on the tunnel magnetoresistive chip follow the ampere rule.
2. The apparatus of claim 1, wherein:
one side of the groove of the U-shaped groove component is hinged with one side of the groove of the V-shaped groove component and can rotate along the direction vertical to the section of the groove;
the other side of the groove of the U-shaped groove component is connected with one side of the groove of the V-shaped groove component through a buckle.
3. The apparatus of claim 1, wherein: the tunnel magnetic resistance chip set up in linear displacement sensor's top includes:
a magnetic sensitive probe is arranged at the top of the linear displacement sensor; the material of the magnetic sensitive probe comprises flame-retardant plastic;
and the tunnel magnetic resistance chip is attached to the PCB and packaged into the magnetic sensitive probe, so that the tunnel magnetic resistance chip is perpendicular to the symmetry axis.
4. The apparatus of claim 1, wherein: the apparatus further comprises a computing unit;
the linear displacement sensor is used for acquiring the linear displacement of the sensor after the device is placed in a to-be-tested electrified lead; the output end of the linear displacement sensor is connected with the input end of the computing unit;
the tunnel magnetic resistance chip is used for acquiring an analog differential signal influenced by the magnetic field intensity; the output end of the tunnel magnetic resistance chip is connected with the input end of the computing unit;
and the calculation unit is used for calculating and obtaining the current value of the electrified lead to be measured according to the linear displacement and the analog differential signal.
5. The apparatus of claim 4, wherein:
the calculating unit is used for calculating and obtaining the magnetic field intensity according to the received analog differential signal;
the computing unit is used for computing and obtaining the distance between the tunnel magnetoresistive chip and the center of the wire according to the received linear displacement;
the calculation unit is used for calculating and obtaining the current value of the electrified lead to be tested according to the magnetic field intensity and the distance between the tunnel magnetic resistance chip and the center of the lead.
6. The apparatus of claim 5, wherein: when the angle of the V-shaped angle of the groove section of the V-shaped groove part is 90 degrees; the current I is calculated in the following way:
wherein, mu0Is the magnetic permeability of air; h is the linear displacement, namely the distance moved by the linear displacement sensor with the vertex of the V-shaped angle as a starting point during measurement; b is the magnetic field intensity.
7. The apparatus of claim 2, wherein:
gradienters are respectively arranged on the surfaces of the V-shaped groove component and the U-shaped groove component; the two gradienters are parallel when the V-shaped groove part and the U-shaped groove part are oppositely arranged;
elastic buffer materials are arranged on the contact surfaces of the V-shaped groove component and the U-shaped groove component when the V-shaped groove component and the U-shaped groove component are oppositely arranged;
the buckle connected with the V-shaped groove component and the U-shaped groove component comprises a locking component capable of adjusting tightness;
before measurement, the readings of the two levels are adjusted to remain the same by adjusting the locking member.
8. A follower current measurement method based on a tunnel magnetoresistive chip, the method comprising:
placing an electrified lead to be measured between the V-shaped groove component and the U-shaped groove component which are oppositely placed, and fastening and fixing the electrified lead through a linear displacement sensor and the V-shaped groove;
acquiring linear displacement through a linear displacement sensor;
acquiring an analog differential signal influenced by the magnetic field intensity through a tunnel magnetoresistive chip;
and calculating to obtain the current value of the electrified lead to be tested according to the linear displacement and the analog differential signal.
9. The method according to claim 8, wherein the calculating and obtaining the current value of the electrified conducting wire to be tested according to the linear displacement and the analog differential signal comprises:
calculating to obtain the magnetic field intensity according to the received analog differential signal;
calculating the distance from the tunnel magnetoresistive chip to the center of the wire according to the received linear displacement;
and calculating to obtain the current value of the electrified lead to be tested according to the magnetic field intensity and the distance between the tunnel magnetic resistance chip and the center of the lead.
10. The method of claim 8, wherein: when the angle of the V-shaped angle of the groove section of the V-shaped groove part is 90 degrees; the current I is calculated in the following way:
wherein, mu0Is the magnetic permeability of air; h is the linear displacement, namely the distance moved by the linear displacement sensor with the vertex of the V-shaped angle as a starting point during measurement; b is the magnetic field intensity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201911182678.5A CN110940842A (en) | 2019-11-27 | 2019-11-27 | Follower current measuring device and method based on tunnel magnetoresistive chip |
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| CN201911182678.5A CN110940842A (en) | 2019-11-27 | 2019-11-27 | Follower current measuring device and method based on tunnel magnetoresistive chip |
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2019
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