A magnetic current sensor

Abstract

The present application provides a magnetic current sensor, which relates to the field of magnetic field measurement technology. The sensor includes: a current conductor to be measured, a magnetic focusing ring, a differential magnetic field generation module and a differential detection module. The differential magnetic field generation module includes: a magnetic field conversion unit and at least two magnetic induction units. The magnetic focusing ring gathers and amplifies the annular induced magnetic field generated by the current conductor to be measured and passes it through the opening of the magnetic focusing ring. The magnetic field conversion unit located at the opening of the magnetic focusing ring forms a magnetic flux path through the magnetic conductivity of a high magnetic permeability metal soft magnetic material, and uses the magnetic flux path to convert the direction of the magnetic field. A magnetic field component parallel to the plane where the magnetic induction unit is located is generated at the air gap of the magnetic flux path, and then a differential voltage signal is generated and detected by the differential detection module. The differential detection of the annular iron core structure combined with the single-sensitivity direction magnetic induction unit can be realized, and the single-chip integrated manufacturing can be achieved. The sensitivity consistency is good, the precision is high, the anti-interference ability is strong, and the application range is wide.

Description

Technical Field

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

[0002] A current sensor is a current detection device that can transform the detected current information into an electrical signal or other required information output in accordance with certain rules to meet certain standards, so as to meet the requirements of information transmission, processing, storage, display, recording and control. It is widely used in many fields such as household appliances, smart grids, electric vehicles, wind power generation, etc. At present, the most widely used current sensor is the magnetic current sensor, which mainly includes fluxgate current sensor, Hall current sensor and magnetoresistive current sensor.

[0003] At present, it is difficult to form a differential magnetic field because the magnetic field direction of the ring core structure of the existing magnetic current sensor is consistent. The ring core is usually directly combined with a fluxgate or Hall element for measurement, and for magnetoresistive devices, two sets of magnetoresistive devices with opposite sensitivity directions are usually used to form a push-pull bridge for the same direction magnetic field detection, which is easy to cause angle deviation and zero point offset, affecting the consistency of sensitivity. Summary of the invention

[0004] In view of this, the purpose of the embodiment of the present application is to provide a magnetic current sensor, in which the magnetic focusing ring gathers and amplifies the annular induced magnetic field generated by the current conductor to be measured and passes it through the opening of the magnetic focusing ring; the magnetic field conversion unit located at the opening of the magnetic focusing ring forms a magnetic flux path through the magnetic conductivity of high magnetic permeability metal soft magnetic materials, and uses the magnetic flux path to convert the direction of the magnetic field, and generates a magnetic field component parallel to the plane where the magnetic induction unit is located at the air gap of the magnetic flux path, thereby generating a differential voltage signal and forming an output signal through a differential detection module, which can realize differential detection combining an annular iron core structure with a single sensitivity direction magnetic induction unit, can be manufactured by single-chip integration, has good sensitivity consistency, high precision, strong anti-interference ability, and a wide range of applications, thereby solving the above-mentioned technical problems.

[0005] In the first aspect, the embodiment of the present application provides a magnetic current sensor, the sensor comprising: a current conductor to be measured, a magnetic focusing ring, a differential magnetic field generating module and a differential detection module; the magnetic focusing ring comprises a magnetic ring structure with an opening; the current conductor to be measured passes through the hollow area of ​​the magnetic ring structure; the differential magnetic field generating module is located at the opening position of the magnetic ring structure; the differential detection module is electrically connected to the differential magnetic field generating module; the differential magnetic field generating module comprises: a magnetic field conversion unit and at least two magnetic induction units; the magnetic field conversion unit is connected to the open magnetic circuit to form a closed magnetic flux path; the magnetic induction unit is located at the air gap of the magnetic field conversion unit, and the sensitivity direction of the magnetic induction unit is perpendicular to the vertical projection direction of the air gap; wherein the magnetic focusing ring is used to gather and amplify the induced magnetic field generated by the current conductor to be measured; the magnetic field conversion unit is used to conduct the gathered and amplified induced magnetic field to the magnetic flux path, and generate a differential magnetic field component in the air gap of the magnetic flux path; the magnetic induction unit is used to generate a differential voltage signal according to the differential magnetic field component; the differential detection module is used to process the differential voltage signal and output the electrical signal to be measured.

[0006] In the above implementation process, the annular induced magnetic field generated by the current conductor to be measured is gathered and amplified by the magnetic focusing ring and then passes through the opening of the magnetic focusing ring; the magnetic field conversion unit located at the opening of the magnetic focusing ring forms a magnetic flux path through the magnetic conductivity of high magnetic permeability metal soft magnetic materials, and uses the magnetic flux path to convert the direction of the magnetic field, and generates a magnetic field component parallel to the plane where the magnetic induction unit is located at the air gap of the magnetic flux path, and then generates a differential voltage signal and forms an output signal through the differential detection module. It can realize differential detection combining the annular iron core structure with the single sensitivity direction magnetic induction unit, can be manufactured by single-chip integration, has good sensitivity consistency, high precision, strong anti-interference ability, and a wide range of applications.

[0007] Optionally, the magnetic focusing ring includes: a single magnetic ring structure with an opening; the magnetic field conversion unit includes: a magnetic field input area, a magnetic field output area, multiple magnetic flux direction conversion areas and multiple magnetic flux path connection areas; the multiple magnetic flux path connection areas include: at least two air gaps located at different positions; the at least two magnetic induction units are correspondingly arranged at the positions of the at least two air gaps; the magnetic field input area is connected to one end of the opening; the magnetic field output area is connected to the other end of the opening; the magnetic flux direction conversion area is located in the corner area of ​​the magnetic field conversion unit, and the magnetic flux path connection area connects two adjacent corner areas, and forms a closed magnetic flux path with the magnetic field input area and the magnetic field output area.

[0008] In the above implementation process, the annular iron core of the single magnetic ring structure is used to gather and amplify the annular induced magnetic field of the current conductor to be measured, and the magnetic conductivity of the metal soft magnetic material on the substrate at the embedded opening in the magnetic field conversion unit is used to form two parallel magnetic flux paths, and magnetic field components with opposite directions are generated at air gaps at different positions to form a differential magnetic field, thereby forming a push-pull bridge structure to achieve differential detection combining an annular iron core structure with a single sensitivity direction magnetic induction unit. At the same time, adjusting the plane where the substrate is located can be applicable to magnetic induction units whose sensitivity directions are perpendicular to and parallel to the plane where they are located, avoiding the angle deviation and zero point offset problems caused by using different sensitivity directions in the prior art, and having good sensitivity consistency, high measurement accuracy and good stability.

[0009] Optionally, the magnetic induction unit also includes: a magnetic shielding reference magnetic induction unit and an external magnetic field reference magnetic induction unit; the magnetic shielding reference magnetic induction unit is located within the vertical projection range of the magnetic field conversion unit; the external magnetic field reference magnetic induction unit is located outside the vertical projection range of the magnetic field conversion unit; the at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, inducing the induced magnetic field to generate a differential voltage signal; or the at least two magnetic induction units and the external magnetic field reference magnetic induction unit are used to form a magnetic resistance of a differential or differential full-bridge structure circuit, inducing the induced magnetic field to generate a differential voltage signal; or the at least one magnetic induction unit and the magnetic shielding reference magnetic induction unit are used to form a magnetic resistance of a differential half-bridge or differential full-bridge structure circuit, inducing the induced magnetic field to generate a differential voltage signal.

[0010] In the above implementation process, an induced magnetic field is formed by adopting a single magnetic ring structure, and a magnetic shielding reference magnetic induction unit and an external magnetic field reference magnetic induction unit are introduced to form a differential half-bridge or differential full-bridge structure, thereby achieving the expansion of the application range and adaptive adjustment of the accuracy, reducing the process cost, and having good stability and high sensitivity consistency.

[0011] Optionally, the magnetic focusing ring includes: at least two magnetic ring structures with openings; the at least two magnetic ring structures are placed side by side along the direction of the current conductor to be measured; the magnetic field conversion unit includes: at least two magnetic field input areas, at least two magnetic field output areas, multiple magnetic flux direction conversion areas and multiple magnetic flux path connection areas; the multiple magnetic flux path connection areas include: at least two air gaps located at different positions; the at least two magnetic induction units are correspondingly arranged at the positions of the at least two air gaps; the magnetic field input area is connected to one end of the opening; the magnetic field output area is connected to the other end of the opening; the magnetic flux direction conversion area is located in the corner area of ​​the magnetic field conversion unit, and the magnetic flux path connection area connects two adjacent corner areas, and forms a closed magnetic flux path with the magnetic field input area and the magnetic field output area; wherein the at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and induce the induced magnetic field to generate a differential voltage signal.

[0012] In the above implementation process, a plurality of magnetic ring structures are placed in parallel to form an integrated structure with a magnetic ring and an additional bracket shell to gather and amplify the annular induced magnetic field of the current conductor to be measured, and the magnetic conductivity of the metal soft magnetic material on the substrate at the embedded opening in the magnetic field conversion unit is used to form two converging and separating magnetic flux paths, and magnetic field components with opposite directions are generated at air gaps at different positions to form a differential magnetic field, thereby forming a push-pull bridge structure to achieve differential detection combining an annular iron core structure with a single sensitivity direction magnetic induction unit. Placing multiple magnetic ring structures in parallel increases the flexibility of the measurement range, and the single sensitivity direction magnetic induction unit avoids the angle deviation and zero point offset problems caused by using different sensitivity directions in the prior art, and has good sensitivity consistency, high measurement accuracy, and good stability.

[0013] Optionally, the magnetic field conversion unit also includes: a flux shielding soft magnetic path; the flux shielding soft magnetic path connects two flux path connection areas among the multiple flux path connection areas that are relatively arranged along the vertical projection direction of the air gap; the flux shielding soft magnetic path is used to isolate external interference magnetic fields parallel to the sensitivity direction of the magnetic induction unit.

[0014] In the above implementation process, by introducing a flux-shielding soft magnetic path, the magnetic field input area and the magnetic field output area are separated, and the external interference magnetic field in the sensitivity direction of the air gap is shielded, thereby further enhancing the measurement accuracy and measurement range and improving the anti-interference ability.

[0015] Optionally, the magnetic field conversion unit also includes: a magnetic flux path connection area; the magnetic flux path connection area is located between two magnetic flux direction conversion areas among the multiple magnetic flux direction conversion areas that are relatively arranged along the vertical projection direction of the air gap; the magnetic flux path connection area is used to divide the differential magnetic field generated at the air gap.

[0016] In the above implementation process, the induced magnetic field is used to generate magnetic field components with opposite directions at air gaps at different positions to form a differential magnetic field, thereby forming a push-pull bridge structure. The magnetic flux path connection area is introduced to regulate the magnetic field size at the air gap, further controlling the measurement range and broadening the application occasions.

[0017] Optionally, the at least two magnetic induction units are correspondingly arranged at at least two air gap positions on one side along the direction from the magnetic field input area to the magnetic field output area.

[0018] In the above implementation process, by arranging at least two magnetic induction units on one side of a single magnetic flux path, a magnetic separation effect can be generated, the magnitude of the magnetic field at the air gap can be regulated, the measurement range can be further controlled, and the application occasions can be broadened.

[0019] Optionally, the magnetic field conversion unit and the at least two magnetic induction units are arranged on a circuit chip using a chip integration process, and the circuit chip is placed at an opening position of the magnetic ring structure.

[0020] In the above implementation process, the magnetic field conversion unit and the magnetic induction unit are processed on the same chip by adopting a single chip integration manufacturing process, thereby reducing the cost.

[0021] Optionally, the magnetic flux direction conversion region and the magnetic flux path connection region share a regular metallic soft magnetic material rectangular structure.

[0022] In the above implementation process, the irregular metal soft magnetic material shared by the magnetic flux direction conversion area and the magnetic flux path connection area in the magnetic field conversion unit is simplified into regular shapes such as rectangles, thereby reducing the process difficulty and cost.

[0023] Optionally, the magnetic flux direction conversion area and the magnetic flux path connection area are formed by a rectangular structure of metallic soft magnetic material with multiple inversions.

[0024] In the above implementation process, by using multiple reversed metal soft magnetic material rectangular structures to form a magnetic field conversion unit, various forms of series-parallel magnetic circuits can be formed, which are suitable for magnetic sensors with various functions, expanding the scope of application and improving practicality.

[0025] Optionally, the differential detection module includes: an open-loop signal conditioning circuit; the open-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the open-loop signal conditioning circuit is used to condition, amplify, temperature compensate and perform linearity correction on the differential voltage signal.

[0026] In the above implementation process, open-loop detection is realized by adopting an open-loop signal conditioning circuit for conditioning amplification, temperature compensation and linearity correction, thereby improving the detection accuracy and achieving better linearity.

[0027] Optionally, the differential detection module includes: a closed-loop signal conditioning circuit and a magnetic field feedback coil; the closed-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the closed-loop signal conditioning circuit, the magnetic field feedback coil and the magnetic induction unit constitute a closed-loop magnetic field feedback structure; the closed-loop signal conditioning circuit is used to condition and amplify the differential voltage signal; the magnetic field feedback coil is used to generate a feedback magnetic field according to the conditioned and amplified signal to achieve dynamic balance of the magnetic field, and sample the current in the magnetic field feedback coil to form the electrical signal to be measured.

[0028] In the above implementation process, closed-loop negative feedback is achieved by using a closed-loop signal conditioning circuit and a magnetic field feedback coil for differential detection, thereby improving accuracy and achieving better linearity.

[0029] Optionally, the magnetic field feedback coil is located inside the magnetic induction unit, inside a circuit chip, passes through a magnetic focusing ring, or surrounds a magnetic focusing ring.

[0030] In the above implementation process, closed-loop negative feedback is achieved by using a closed-loop signal conditioning circuit and a magnetic field feedback coil for differential detection. The magnetic field feedback coil can be located inside the magnetic induction unit, inside the circuit chip, or directly pass through the magnetic focusing ring and surround the magnetic focusing ring, thereby improving the negative feedback efficiency.

[0031] In order to make the above-mentioned objects, features and advantages of the present application more obvious and understandable, embodiments are given below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of a magnetic current sensor provided in an embodiment of the present application;

[0034] Figure 2 A schematic cross-sectional view of a magnetic current sensor provided in an embodiment of the present application;

[0035] Figure 3 A schematic cross-sectional view of a first differential magnetic field generating module structure provided in an embodiment of the present application;

[0036] Figure 4 A magnetic flux path simulation diagram of the first magnetic field conversion unit provided in an embodiment of the present application;

[0037] Figure 5 A schematic diagram of a magnetic current sensor provided by an embodiment of the present application, in which a magnetic field conversion unit is located in an XZ plane;

[0038] Figure 6 A schematic cross-sectional view of a second differential magnetic field generating module structure provided in an embodiment of the present application;

[0039] Figure 7 A magnetic flux path simulation diagram of the second magnetic field conversion unit provided in an embodiment of the present application;

[0040] Figure 8 A schematic cross-sectional view of a third differential magnetic field generating module structure provided in an embodiment of the present application;

[0041] Fig. 9 A magnetic flux path simulation diagram of a third magnetic field conversion unit provided in an embodiment of the present application;

[0042] Fig.10 A schematic diagram of a magnetic current sensor with a multi-magnetic ring structure provided in an embodiment of the present application;

[0043] Fig.11 A schematic cross-sectional view of a fourth differential magnetic field generating module structure provided in an embodiment of the present application;

[0044] Fig.12 A simulation diagram of the magnetic flux path of the fourth magnetic field conversion unit provided in an embodiment of the present application applying a magnetic field in the Z-axis direction;

[0045] Fig.13 A simulation diagram of the magnetic flux path of the fourth magnetic field conversion unit provided in an embodiment of the present application applying a magnetic field in the Y-axis direction;

[0046] Fig.14 A schematic cross-sectional view of a fifth differential magnetic field generating module structure provided in an embodiment of the present application;

[0047] Fig.15 A simulation diagram of the magnetic flux path of the fifth magnetic field conversion unit provided in an embodiment of the present application applying a magnetic field in the Z-axis direction;

[0048] Fig.16 A simulation diagram of the magnetic flux path of the fifth magnetic field conversion unit provided in an embodiment of the present application applying a magnetic field in the Y-axis direction;

[0049] Fig.17 A schematic diagram of a metal soft magnetic material structure of a differential magnetic field generation module provided in an embodiment of the present application;

[0050] Fig.18 A schematic diagram of a metal soft magnetic material structure of another differential magnetic field generating module provided in an embodiment of the present application;

[0051] Fig.19 A cross-sectional schematic diagram of the position of a magnetic field feedback coil provided in an embodiment of the present application.

[0052] Icon: 01-magnetic current sensor; 10-current conductor to be measured; 20-magnetic focusing ring; 30-differential magnetic field generation module; 40-differential detection module; 41-magnetic field feedback coil. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0054] It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. The terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the statement "comprising one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements. The terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0055] The inventor of this application has noticed that the most widely used current sensor is the magnetic current sensor, which mainly includes fluxgate current sensor, Hall current sensor and magnetoresistive current sensor. The fluxgate current sensor uses a high permeability core, which has good linearity, high precision and good temperature drift performance, but is large in size, complex in circuit and high in cost; the magnetic field sensitivity direction of the Hall current sensor is perpendicular to the plane where the Hall element is located, and the technology is mature, but the sensitivity is low, the temperature drift performance is relatively poor, and the bandwidth is small. There are two main current input methods of the Hall current sensor, one is to sense the magnetic field of the current conductor to be measured through the annular iron core, and the other is a small chip-level current sensor, whose current to be measured is directly input into the U-shaped copper conduction path; the magnetoresistive current sensor mainly includes: anisotropic magnetoresistance AMR, giant magnetoresistance GMR and tunnel magnetoresistance TMR current sensor, whose magnetic field sensitivity direction is parallel to the plane where the magnetoresistance device is located, with high sensitivity and good linearity, but the magnetic field measurement range of the magnetoresistance device is smaller than that of the Hall element. Since the magnetic field direction of the above-mentioned existing annular iron core structure is consistent, it is difficult to form a differential magnetic field. The annular core is usually directly combined with a fluxgate or Hall element for measurement. The magnetoresistive device usually uses two sets of magnetoresistive devices with opposite sensitivity directions to form a push-pull bridge for the same direction magnetic field detection, which is easy to cause angle deviation and zero point offset, affecting the sensitivity consistency. In view of this, the embodiment of the present application provides a magnetic current sensor 01 as described below.

[0056] See also Figure 1 , Figure 1 A schematic diagram of a magnetic current sensor 01 provided in an embodiment of the present application. The embodiment of the present application is explained in detail below. The sensor includes: a current conductor 10 to be measured, a magnetic ring 20, a differential magnetic field generation module 30 and a differential detection module 40; the magnetic ring 20 includes a magnetic ring structure with an opening; the current conductor 10 to be measured passes through the hollow area of ​​the magnetic ring structure; the differential magnetic field generation module 30 includes: a magnetic field conversion unit, at least two magnetic induction units;

[0057] The differential magnetic field generating module 30 is located at the opening position of the magnetic ring structure; the differential detection module 40 is electrically connected to the differential magnetic field generating module 30; the magnetic field conversion unit is connected to the open magnetic circuit to form a closed magnetic flux path; the magnetic induction unit is located at the air gap of the magnetic field conversion unit, and the sensitivity direction of the magnetic induction unit is perpendicular to the vertical projection direction of the air gap; wherein, the magnetic focusing ring 20 is used to gather and amplify the induced magnetic field generated by the current conductor 10 to be measured; the magnetic field conversion unit is used to guide the gathered and amplified induced magnetic field to the magnetic flux path, and generate a differential magnetic field component in the air gap of the magnetic flux path; the magnetic induction unit is used to generate a differential voltage signal according to the differential magnetic field component; the differential detection module 40 is used to process the differential voltage signal and output the electrical signal to be measured.

[0058] Exemplarily, the magnetic focusing ring 20 may be a single magnetic ring structure or a plurality of magnetic ring structures placed in parallel to form an integrated ring structure; for example: Figure 2 The magnetic focusing ring 20 shown has an annular structure parallel to the XZ plane, an opening is provided on the annular structure and the height of the opening is along the Z-axis direction, the current conductor 10 to be measured passes through the hollow area inside the magnetic focusing ring 20, and the magnetic focusing ring 20 gathers and amplifies the annular induced magnetic field generated by the current conductor 10 to be measured and then passes through the opening along the Z-axis direction. The differential magnetic field generation module 30 can be: sensing the induced magnetic field generated by the current to be measured, and sensing the magnetic field of the current to be measured to generate a corresponding differential voltage signal through at least one magnetic path structure among differential full bridge, differential half bridge, push-pull full bridge and push-pull half bridge, and can specifically include a magnetic field conversion unit and at least two magnetic induction units; wherein the magnetic field conversion unit can be composed of a metallic soft magnetic material with high magnetic permeability, and the magnetic flux path of the magnetic field conversion unit is formed by the magnetic conductivity of the metallic soft magnetic material; the magnetic induction unit ( Figure 1 The magnetic sensing unit (not directly shown in the figure) may be: two or more giant magnetic impedance GMI, fluxgate, Hall element, anomalous Hall element AHE, or magnetoresistive sensitive element whose vertical projections are located at the air gap position of the magnetic field conversion unit; for the magnetoresistive sensitive element, the magnetic sensing unit may be respectively composed of one or more magnetoresistive sensitive elements connected in series and in parallel, and the magnetoresistive sensitive element is one of anisotropic magnetoresistive AMR, giant magnetoresistive GMR, tunnel magnetoresistive TMR, vertical tunnel magnetoresistive PTMR and giant magnetoresistive CMR. Differential detection module 40 ( Figure 1 (not directly shown) may be: an open-loop signal conditioning circuit or a closed-loop signal conditioning circuit, which conditions, amplifies, temperature compensates and corrects the linearity of the differential voltage signal to form the output electrical signal to be measured of the magnetic current sensor 01.

[0059] Optionally, Figure 2As shown, taking the magnetic focusing ring 20 with a single magnetic ring structure as an example, assuming that the current direction in the current conductor 10 to be measured is in the negative direction of the Y axis (perpendicular to the paper and outward), the induced magnetic field in the magnetic focusing ring 20 is counterclockwise, that is, the direction of the induced magnetic field passing through the opening is the positive direction of the Z axis. The magnetic focusing ring 20 gathers and amplifies the annular induced magnetic field generated by the current conductor 10 to be measured, and then passes through the opening along the Z axis. The induced magnetic field at the opening position of the magnetic focusing ring 20 along the Z axis direction is converted in direction through the magnetic flux path, so that the induced magnetic field in the Z axis direction generates a component parallel to the XY plane. When converting the direction of the magnetic field, the magnetic flux path of the induced magnetic field can be offset by a spatial solid angle of 0-90 degrees according to the structure of the magnetic flux path, generating an X-axis component or a Y-axis component; at the same time, since the magnetic field conversion unit is provided with one or more air gaps, the induced magnetic field along the Z-axis direction can generate an X-axis component or a Y-axis component in the air gap after the above-mentioned conversion of the magnetic field direction; a magnetic field conversion unit and a magnetic induction unit are arranged at the opening position of the magnetic focusing ring 20 parallel to the XZ plane, and the sensitivity direction of the magnetic induction unit is the same, perpendicular to the air gap and along the X-axis or the Y-axis, and the magnetic induction unit senses the magnetic field of the magnetic field conversion unit, generates a differential voltage signal and forms an output electrical signal to be measured through the differential detection module 40. In particular, Figure 1 The magnetic field conversion unit in the apparatus is located in the YZ plane. The magnetic conductivity of the metal soft magnetic material of the magnetic field conversion unit can make the induced magnetic field in the Z-axis direction produce a component parallel to the XY plane. The specific direction of the differential magnetic field component is determined by the plane where the magnetic field conversion unit is located. Since the magnetic field conversion unit is located in the YZ plane, the induced magnetic field in the Z-axis direction can generate opposite magnetic field components in the positive and negative directions of the Y-axis at the air gaps at different positions, forming a differential magnetic field. The magnetic induction unit with the sensitivity direction parallel to the Y-axis can be used for measurement.

[0060] The annular induced magnetic field generated by the current conductor 10 to be measured is gathered and amplified by the magnetic focusing ring 20 and then passes through the opening of the magnetic focusing ring 20; the magnetic field conversion unit located at the opening of the magnetic focusing ring 20 forms a magnetic flux path through the magnetic conductivity of high magnetic permeability metal soft magnetic materials, and uses the magnetic flux path to convert the direction of the magnetic field, and generates a magnetic field component parallel to the plane where the magnetic induction unit is located at the air gap of the magnetic flux path, and then generates a differential voltage signal and forms an output signal through the differential detection module 40, which can realize differential detection combining the annular iron core structure with the single-sensitivity direction magnetic induction unit, can be manufactured by single-chip integration, has good sensitivity consistency, high precision, strong anti-interference ability, and a wide range of applications.

[0061] In one embodiment, the magnetic focusing ring 20 comprises: a single magnetic ring structure with an opening; the magnetic field conversion unit comprises: a magnetic field input area, a magnetic field output area, a plurality of magnetic flux direction conversion areas and a plurality of magnetic flux path connection areas; the plurality of magnetic flux path connection areas comprise: at least two air gaps located at different positions; at least two magnetic induction units are correspondingly arranged at the positions of at least two air gaps;

[0062] The magnetic field input area is connected to one end of the opening; the magnetic field output area is connected to the other end of the opening; the magnetic flux direction conversion area is located in the corner area of ​​the magnetic field conversion unit, and the magnetic flux path connection area connects two adjacent corner areas and forms a closed magnetic flux path with the magnetic field input area and the magnetic field output area.

[0063] Exemplarily, the magnetic field conversion unit includes a single independent magnetic field input area and a single independent magnetic field output area, that is, the corresponding magnetic flux path has only one input port and one output port, and also includes multiple magnetic flux direction conversion areas and multiple magnetic flux path connection areas. Figure 3 The structure of a differential magnetic field generating module 30 composed of a magnetic field conversion unit and four magnetic induction units is shown. The arrow direction indicated by "sen" is the sensitivity direction of the magnetic induction unit. The magnetic field conversion unit includes a magnetic field input area 2A, a magnetic field output area 2B, a magnetic flux direction conversion area (2Ca, 2Cb, 2Cc, 2Cd, 2Ce, 2Cf), and a magnetic flux path connection area (2Da, 2Db, 2Dc, 2Dd, 2De, 2Df). The magnetic field conversion unit can be located at Figure 2 The magnetic field concentrator 20 shown is in an open position and is made of a metal soft magnetic material with high magnetic permeability. The magnetic field conversion unit is connected to the magnetic field concentrator 20. The metal soft magnetic material of the magnetic field conversion unit is located on the substrate embedded in the opening, so that the magnetic field output area 2B and the magnetic field input area 2A connect the upper and lower ends of the opening of the magnetic field concentrator 20 to form a closed magnetic circuit. Assuming that the magnetic field conversion unit is located in the YZ plane, the magnetic flux direction conversion area 2Ca includes three ports pointing to the positive direction of the Y axis, the negative direction of the Y axis, and the positive direction of the Z axis, the magnetic flux direction conversion area 2Cb is a corner pointing to the negative direction of the Y axis and the negative direction of the Z axis, the magnetic flux direction conversion area 2Cc is a corner pointing to the negative direction of the Y axis and the positive direction of the Z axis, the magnetic flux direction conversion area 2Cd includes three ports pointing to the positive direction of the Y axis, the negative direction of the Y axis, and the negative direction of the Z axis, the magnetic flux direction conversion area 2Ce is a corner pointing to the positive direction of the Y axis and the negative direction of the Z axis, and the magnetic flux direction conversion area 2Cf is a corner pointing to the positive direction of the Y axis and the positive direction of the Z axis. The magnetic flux path connection area 2Da is connected to the magnetic flux direction conversion areas 2Ca and 2Cb in the Y-axis direction, the magnetic flux path connection area 2Db is connected to the magnetic flux direction conversion areas 2Cb and 2Cc in the Z-axis direction, the magnetic flux path connection area 2Dc is connected to the magnetic flux direction conversion areas 2Cc and 2Cd in the Y-axis direction, the magnetic flux path connection area 2Dd is connected to the magnetic flux direction conversion areas 2Ca and 2Ce in the Y-axis direction, the magnetic flux path connection area 2De is connected to the magnetic flux direction conversion areas 2Ce and 2Cf in the Z-axis direction, and the magnetic flux path connection area 2Df is connected to the magnetic flux direction conversion areas 2Cf and 2Cd in the Y-axis direction; and the magnetic flux path connection areas 2Da, 2Dc, 2Dd, and 2Df are respectively provided with two air gaps that penetrate the metal soft magnetic material along the Z-axis direction.

[0064] When the direction of the induced magnetic field passing through the opening is the positive direction of the Z axis, the metal soft magnetic material of the magnetic field conversion unit forms a magnetic flux path through magnetic conductivity. After the induced magnetic field enters from the magnetic field input area 2A, it is twisted to the positive direction of the Y axis and the negative direction of the Y axis on both sides in the magnetic flux direction conversion area 2Cd to form two parallel magnetic flux paths. One of the magnetic paths passes through the magnetic flux path connection area 2Dc with an air gap along the positive direction of the Y axis, and generates a magnetic field component in the positive direction of the Y axis in the air gap, and then passes through the magnetic flux direction conversion area 2Cc, the magnetic flux path connection area 2Db, and the magnetic flux direction conversion area 2Cb in sequence, twisting the magnetic path from the positive direction of the Y axis to the negative direction of the Y axis, and then passes through the magnetic flux path connection area 2Da with an air gap, and generates a magnetic field component in the negative direction of the Y axis in the air gap. The other magnetic circuit passes through the magnetic flux path connection area 2Df with an air gap along the negative direction of the Y axis, and generates a magnetic field component in the negative direction of the Y axis in the air gap; the magnetic circuit then passes through the magnetic flux direction conversion area 2Cf, the magnetic flux path connection area 2De, and the magnetic flux direction conversion area 2Ce in sequence, twisting the magnetic circuit from the negative direction of the Y axis to the positive direction of the Y axis, and then passes through the magnetic flux path connection area 2Dd with an air gap, and generates a magnetic field component in the positive direction of the Y axis in the air gap; finally, the two magnetic circuits enter the magnetic flux direction conversion area 2Ca from the magnetic flux path connection area 2Da along the negative direction of the Y axis and the magnetic flux path connection area 2Dd along the positive direction of the Y axis, and then twist back to the positive direction of the Z axis, and then pass through the magnetic field output area 2B. In this way, the induced magnetic field in the Z axis direction can generate opposite magnetic field components in the positive and negative directions of the Y axis at air gaps at different positions, forming a differential magnetic field. Figure 4 As shown, from Figure 3 It can be seen from the magnetic flux path simulation diagram after the magnetic field conversion unit is added with the positive direction magnetic field of the Z axis: the induced magnetic field along the Z axis is twisted and reversed on both sides, forming two magnetic flux paths in parallel, and finally twisted back to the Z axis direction. The magnetic flux path of the induced magnetic field is subjected to a magnetic conduction offset of 0-90 degrees in a spatial solid angle according to the structure of the magnetic flux direction conversion zone, and a component parallel to the XY plane is generated at the air gaps of the magnetic flux path connection areas 2Da, 2Dc, 2Dd, and 2Df. Specifically, an obvious magnetic field component in the positive direction of the Y axis can be generated at the air gaps of the magnetic flux path connection areas 2Dc and 2Dd, and an obvious magnetic field component in the negative direction of the Y axis can be generated at the air gaps of the magnetic flux path connection areas 2Da and 2Df.

[0065] Among them, the four magnetic induction units can be respectively: Figure 3In 3a, 3b, 3c, and 3d, the sensitivity directions of all magnetic induction units are in the positive direction of the Y axis, and the vertical projections of the magnetic induction units 3a, 3b, 3c, and 3d are respectively located at the air gap positions of the magnetic flux path connection areas 2Da, 2Dc, 2Dd, and 2Df in the magnetic field conversion unit. If the magnetic induction unit is a tunnel magnetoresistance TMR as an example, since the magnetic field component at the air gap of the magnetic flux path connection areas 2Dc and 2Dd is in the positive direction of the Y axis, and the magnetic field component at the air gap of the magnetic flux path connection areas 2Da and 2Df is in the negative direction of the Y axis, the resistance values ​​of the magnetic induction units 3b and 3c decrease, and the resistance values ​​of the magnetic induction units 3a and 3d increase. Therefore, a push-pull full-bridge structure can be used to sense the magnetic field in the positive direction of the Z axis to generate a differential voltage signal. By using an open-loop signal conditioning circuit, the differential voltage signal is conditioned, amplified, temperature compensated, and linearly corrected to form the output electrical signal to be measured by the current sensor. Further, the following can be used: Figure 5 The magnetic field conversion unit shown in the XZ plane performs differential detection, which can make the induced magnetic field in the Z-axis direction generate opposite magnetic field components in the positive and negative directions of the X-axis at air gaps at different positions, forming a differential magnetic field, and is measured using a magnetic induction unit whose sensitivity direction is parallel to the X-axis.

[0066] By using a single magnetic ring structure of the annular iron core to gather and amplify the annular induced magnetic field of the current conductor 10 to be measured, the magnetic conductivity of the metal soft magnetic material on the substrate at the embedded opening in the magnetic field conversion unit is used to form two parallel magnetic flux paths, and magnetic field components with opposite directions are generated at air gaps at different positions to form a differential magnetic field, thereby forming a push-pull bridge structure to achieve differential detection combining an annular iron core structure with a single sensitivity direction magnetic induction unit. At the same time, adjusting the plane where the substrate is located can be applicable to magnetic induction units whose sensitivity directions are perpendicular to and parallel to the plane where they are located, avoiding the angle deviation and zero point offset problems caused by using different sensitivity directions in the prior art, and having good sensitivity consistency, high measurement accuracy and good stability.

[0067] In one embodiment, the magnetic induction unit further includes: a magnetic shielding reference magnetic induction unit and an external magnetic field reference magnetic induction unit;

[0068] The magnetic shielding reference magnetic induction unit is located within the vertical projection range of the magnetic field conversion unit; the external magnetic field reference magnetic induction unit is located outside the vertical projection range of the magnetic field conversion unit; at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and the induced magnetic field is induced to generate a differential voltage signal; or at least two magnetic induction units and an external magnetic field reference magnetic induction unit are used to form a magnetic resistance of a differential or differential full-bridge structure circuit, and the induced magnetic field is induced to generate a differential voltage signal; or at least one magnetic induction unit and a magnetic shielding reference magnetic induction unit are used to form a magnetic resistance of a differential half-bridge or differential full-bridge structure circuit, and the induced magnetic field is induced to generate a differential voltage signal.

[0069] For example, Figure 6 As shown, a differential magnetic field generation module 30 structure is composed of a magnetic field conversion unit, two magnetic induction units, two magnetic shielding reference magnetic induction units and an external magnetic field reference magnetic induction unit. The magnetic field conversion unit includes a magnetic field input area 2A, a magnetic field output area 2B, a magnetic flux direction conversion area (2Ca, 2Cb, 2Cc, 2Cd), and a magnetic flux path connection area (2Da, 2Db, 2Dc). The magnetic field conversion unit can be located in the XZ plane or the YZ plane. The magnetic field conversion unit is located in the YZ plane as an example for explanation. The magnetic focusing ring 20 also adopts a single magnetic ring structure, and its annular structure is parallel to the YZ plane, and the opening height is along the Z axis. The current conductor 10 to be measured passes through the hollow area inside the magnetic focusing ring 20. The magnetic focusing ring 20 gathers and amplifies the annular induced magnetic field generated by the current conductor 10 to be measured and passes through the opening along the Z axis. Let the current direction in the current conductor 10 to be measured be the positive direction of the Y axis, and the direction of the induced magnetic field passing through the opening is the negative direction of the Z axis. The magnetic flux direction conversion area 2Ca is a corner pointing to the positive direction of the Y axis and the positive direction of the Z axis, the magnetic flux direction conversion area 2Cb is a corner pointing to the negative direction of the Y axis and the negative direction of the Z axis, the magnetic flux direction conversion area 2Cc is a corner pointing to the negative direction of the Y axis and the positive direction of the Z axis, and the magnetic flux direction conversion area 2Cd is a corner pointing to the positive direction of the Y axis and the negative direction of the Z axis. The magnetic flux path connection area 2Da connects the magnetic flux direction conversion areas 2Ca and 2Cb in the Y axis direction, the magnetic flux path connection area 2Db connects the magnetic flux direction conversion areas 2Cb and 2Cc in the Z axis direction, and the magnetic flux path connection area 2Dc connects the magnetic flux direction conversion areas 2Cc and 2Cd in the Y axis direction; and the magnetic flux path connection areas 2Da and 2Dc are respectively provided with two air gaps penetrating the metal soft magnetic material along the Z axis direction.

[0070] When the direction of the induced magnetic field passing through the opening is the negative direction of the Z axis, the metal soft magnetic material of the magnetic field conversion unit forms a magnetic flux path through magnetic conductivity. The induced magnetic field enters from the magnetic field input area 2A, is twisted to the positive direction of the Y axis through the magnetic flux direction conversion area 2Ca, and then passes through the magnetic flux path connection area 2Da with an air gap, and generates a magnetic field component in the positive direction of the Y axis in the air gap; then it passes through the magnetic flux direction conversion area 2Cb, the magnetic flux path connection area 2Db, and the magnetic flux direction conversion area 2Cc in turn, and the magnetic path is twisted from the positive direction of the Y axis to the negative direction of the Y axis, and then passes through the magnetic flux path connection area 2Dc with an air gap, and generates a magnetic field component in the negative direction of the Y axis in the air gap; finally, the magnetic path is twisted back to the negative direction of the Z axis through the magnetic flux direction conversion area 2Cd, and then passes through the magnetic field output area 2B. In this way, the induced magnetic field in the negative direction of the Z axis can generate opposite magnetic field components in the positive and negative directions of the Y axis at air gaps at different positions, forming a differential magnetic field. Figure 7 As shown, from Figure 6It can be seen from the magnetic flux path simulation diagram after the magnetic field conversion unit is added with the negative magnetic field of the Z axis that the induced magnetic field along the negative direction of the Z axis is gathered and amplified by the metal soft magnetic material to form a magnetic circuit, and the magnetic permeability offset of 0-90 degrees in the magnetic flux direction conversion area 2Ca, 2Cb, 2Cc, and 2Cd occurs in sequence, and the components parallel to the XY plane are generated at the air gaps of the magnetic flux path connection areas 2Da and 2Dc. Specifically, an obvious magnetic field component in the positive direction of the Y axis can be generated at the air gap of the magnetic flux path connection area 2Da, and an obvious magnetic field component in the negative direction of the Y axis can be generated at the air gap of the magnetic flux path connection area 2Dc.

[0071] The two magnetic induction units, the two magnetic shielding reference magnetic induction units and the one external magnetic field reference magnetic induction unit may be respectively: Figure 6 The middle magnetic induction unit 31a, 31b, the magnetic shielding reference magnetic induction unit 32a, 32b, and the external magnetic field reference magnetic induction unit 33. The sensitivity direction of all magnetic induction units is the positive direction of the Y axis. The vertical projection of the magnetic induction unit 31a is located at the air gap position of the magnetic flux path connection area 2Da in the magnetic field conversion unit, and the vertical projection of the magnetic induction unit 31b is located at the air gap position of the magnetic flux path connection area 2Dc, so the resistance value of the magnetic induction unit 31a decreases and the resistance value of the magnetic induction unit 31b increases. The magnetic shielding reference magnetic induction units 32a and 32b are located within the vertical projection range of the soft magnetic metal material of the magnetic field conversion unit. Due to the magnetic shielding effect, the resistance value can be regarded as approximately unchanged. The external magnetic field reference magnetic induction unit 33 is located outside the vertical projection range of the magnetic field conversion unit. Its position is far away from the metal soft magnetic material of the magnetic field conversion unit and is directly affected by the external magnetic field. Therefore, according to actual measurement requirements, when detecting with small measurement range and high sensitivity, the magnetic induction units 31a and 31b can be used to form a push-pull half-bridge structure to sense the magnetic field in the negative direction of the Z axis and generate a differential voltage signal; when detecting with low sensitivity and large measurement range, the magnetic induction units 31a and 31b can be selected to form a differential half-bridge or differential full-bridge structure with the external magnetic field reference magnetic induction unit 33 to sense the magnetic field in the negative direction of the Z axis and generate a differential voltage signal; the magnetic induction units 31a and 31b can also be selected to form a differential half-bridge or differential full-bridge structure with the magnetic shield reference magnetic induction units 32a and 32b or a reference resistor with a fixed resistance value to sense the magnetic field in the negative direction of the Z axis and generate a differential voltage signal. The open-loop signal conditioning circuit is used to condition, amplify, temperature compensate and linearize the differential voltage signal to form the output electrical signal to be measured by the current sensor. Among them, the sensitivity direction of all magnetic induction units can be the positive direction of the Y-axis. When the sensitivity direction of the selected magnetic induction unit is parallel to the plane where it is located (such as TMR, AMR, GMR, etc.), a single chip integration preparation process can be used to achieve one-time single-chip preparation.

[0072] By adopting a single magnetic ring structure to form an induced magnetic field, introducing a magnetic shielding reference magnetic induction unit and an external magnetic field reference magnetic induction unit, a differential half-bridge or differential full-bridge structure is formed to achieve the expansion of the application range and adaptive adjustment of accuracy, reduce process costs, and have good stability and high sensitivity consistency.

[0073] In one embodiment, the magnetic focusing ring 20 includes: at least two magnetic ring structures with openings; at least two magnetic ring structures are placed side by side along the direction of the current conductor 10 to be measured; the magnetic field conversion unit includes: at least two magnetic field input areas, at least two magnetic field output areas, multiple magnetic flux direction conversion areas and multiple magnetic flux path connection areas; the multiple magnetic flux path connection areas include: at least two air gaps located at different positions; at least two magnetic induction units are correspondingly arranged at the positions of at least two air gaps;

[0074] The magnetic field input area is connected to one end of the opening; the magnetic field output area is connected to the other end of the opening; the magnetic flux direction conversion area is located in the corner area of ​​the magnetic field conversion unit, and the magnetic flux path connection area connects two adjacent corner areas and forms a closed magnetic flux path with the magnetic field input area and the magnetic field output area; wherein at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and the induced magnetic field generates a differential voltage signal.

[0075] Exemplarily, the magnetic field conversion unit includes multiple independent magnetic field input areas and multiple independent magnetic field output areas, that is, the corresponding magnetic flux path has multiple input ports and multiple output ports, and also includes multiple magnetic flux direction conversion areas and multiple magnetic flux path connection areas. Figure 8 As shown, the magnetic field conversion unit includes a magnetic field input area (2Aa, 2Ab), a magnetic field output area (2Ba, 2Bb), a magnetic flux direction conversion area (2Ca, 2Cb, 2Cc, 2Cd, 2Ce, 2Cf), and a magnetic flux path connection area (2Da, 2Db, 2Dc, 2Dd, 2De). The magnetic field conversion unit is located in the XZ plane or the YZ plane, and the magnetic field conversion unit is located in the YZ plane as an example for introduction. The 1a and 1b additional bracket shells of the magnetic focusing ring 20 with two magnetic ring structures placed in parallel form an integrated structure. The annular structures of the magnetic focusing ring 20 1a and 1b can be parallel to the YZ plane, and the magnetic focusing ring 20 1a and 1b are provided with openings and the opening height is along the Z-axis direction; the current conductor 10 to be measured passes through the hollow areas of the rings 1a and 1b of the magnetic focusing ring 20, and the magnetic focusing ring 20 1a and 1b gather and amplify the annular induced magnetic field generated by the current conductor 10 to be measured and then pass through the opening along the Z-axis direction. Let the direction of the current in the current conductor 10 to be measured be the positive direction of the Y axis, and the direction of the induced magnetic field passing through the opening be the negative direction of the Z axis, thus defined Figure 8The magnetic field input area 2Aa, 2Ab of the magnetic field conversion unit shown is located at one end of the magnetic field conversion unit in the positive direction of the Z axis, and the magnetic field output area 2Ba, 2Bb is located at one end of the magnetic field conversion unit in the negative direction of the Z axis. The magnetic field conversion unit is located at the opening position of 1a, 1b of the magnetic field focusing ring 20 and is composed of a metal soft magnetic material with high magnetic permeability. In this embodiment, the magnetic field conversion unit is connected to 1a, 1b of the magnetic field focusing ring 20, and the metal soft magnetic material of the magnetic field conversion unit is located on the substrate embedded in the opening, so that the magnetic field input area 2Aa, 2Ab and the magnetic field output area 2Ba, 2Bb are respectively connected to the upper and lower ends of the openings of 1a, 1b of the magnetic field focusing ring 20 to form a closed magnetic circuit. The flux direction conversion zone 2Ca is a corner pointing to the negative direction of the Y axis and the positive direction of the Z axis, the flux direction conversion zone 2Cb includes three ports pointing to the positive direction of the Y axis, the negative direction of the Y axis, and the negative direction of the Z axis, the flux direction conversion zone 2Cc includes three ports pointing to the positive direction of the Y axis, the negative direction of the Y axis, and the positive direction of the Z axis, the flux direction conversion zone 2Cd is a corner pointing to the negative direction of the Y axis and the negative direction of the Z axis, the flux direction conversion zone 2Ce is a corner pointing to the positive direction of the Y axis and the positive direction of the Z axis, and the flux direction conversion zone 2Cf is a corner pointing to the positive direction of the Y axis and the negative direction of the Z axis. The magnetic flux path connection area 2Da is connected to the magnetic flux direction conversion areas 2Ca and 2Cb in the Y-axis direction, the magnetic flux path connection area 2Db is connected to the magnetic flux direction conversion areas 2Cc and 2Cd in the Y-axis direction, the magnetic flux path connection area 2Dc is connected to the magnetic flux direction conversion areas 2Cb and 2Ce in the Y-axis direction, the magnetic flux path connection area 2Dd is connected to the magnetic flux direction conversion areas 2Cc and 2Cf in the Y-axis direction, and the magnetic flux path connection area 2De is connected to the magnetic flux direction conversion areas 2Cb and 2Cc in the Z-axis direction; and the magnetic flux path connection areas 2Da, 2Db, 2Dc, and 2Dd are respectively provided with two air gaps that penetrate the metal soft magnetic material along the Z-axis direction.

[0076] When the direction of the induced magnetic field passing through the opening is the negative direction of the Z axis, the metal soft magnetic material of the magnetic field conversion unit forms a magnetic flux path through magnetic conductivity, and the induced magnetic field enters from both ends of the magnetic field input area 2Aa and 2Ab. The magnetic circuit at the end of the magnetic field input area 2Aa is twisted to the negative direction of the Y axis through the magnetic flux direction conversion area 2Ca, and then passes through the magnetic flux path connection area 2Da with an air gap, and generates a magnetic field component in the negative direction of the Y axis in the air gap; the magnetic circuit at the end of the magnetic field input area 2Ab is twisted to the positive direction of the Y axis through the magnetic flux direction conversion area 2Ce, and then passes through the magnetic flux path connection area 2Dc with an air gap, and generates a magnetic field component in the positive direction of the Y axis in the air gap. The two magnetic circuits passing through the magnetic flux path connection areas 2Da and 2Dc enter the magnetic flux direction conversion area 2Cb from both sides respectively, and are twisted to the negative direction of the Z axis. After that, the magnetic circuit along the negative direction of the Z axis enters the magnetic flux direction conversion area 2Cc through the magnetic flux path connection area 2De, and is twisted to the positive direction of the Y axis and the negative direction of the Y axis on both sides to re-form two magnetic flux paths. One of the magnetic circuits passes through the magnetic flux path connection area 2Db with an air gap along the positive direction of the Y axis, and generates a magnetic field component in the positive direction of the Y axis in the air gap, and then passes through the magnetic flux direction conversion area 2Cd to twist the magnetic circuit back to the negative direction of the Z axis and passes through the magnetic field output area 2Ba; the other magnetic circuit passes through the magnetic flux path connection area 2Dd with an air gap along the negative direction of the Y axis, and generates a magnetic field component in the negative direction of the Y axis in the air gap, and then passes through the magnetic flux direction conversion area 2Cf to twist the magnetic circuit back to the negative direction of the Z axis and passes through the magnetic field output area 2Bb. In this way, the induced magnetic field in the negative direction of the Z axis can generate opposite magnetic field components in the positive and negative directions of the Y axis at air gaps at different positions, forming a differential magnetic field. Fig. 9 As shown, from Figure 8 From the simulation diagram of the magnetic flux path after the magnetic field conversion unit is added with the negative magnetic field of the Z axis, it can be seen that: the induced magnetic field along the negative direction of the Z axis is divided into two symmetrical magnetic circuits on both sides, and the two magnetic circuits are respectively twisted to the positive and negative directions of the Y axis and then merged and twisted back to the negative direction of the Z axis; then they are twisted again on both sides, twisted to the positive and negative directions of the Y axis to re-form two magnetic flux paths, and each is twisted back to the negative direction of the Z axis. The magnetic flux path of the induced magnetic field is subjected to a magnetic conduction offset of 0-90 degrees in a spatial solid angle according to the structure of the magnetic flux direction conversion zone, and a component parallel to the XY plane is generated at the air gaps of the magnetic flux path connection areas 2Da, 2Db, 2Dc, and 2Dd. Specifically, an obvious magnetic field component in the negative direction of the Y axis can be generated at the air gaps in the magnetic flux path connection areas 2Da and 2Dd, and an obvious magnetic field component in the positive direction of the Y axis can be generated at the air gaps in the magnetic flux path connection areas 2Db and 2Dc. As Fig.10 As shown, 1a and 1b of the magnetic focusing ring 20 can be connected to the magnetic field conversion unit located in the YZ plane respectively, and the magnetic field input areas 2Aa and 2Ab and the magnetic field output areas 2Ba and 2Bb are respectively connected to the upper and lower ends of the openings of 1a and 1b of the magnetic focusing ring 20 to form a closed magnetic circuit.

[0077] Among them, the sensitivity directions of the magnetic induction units 3a, 3b, 3c, and 3d are all in the positive direction of the Y axis, and the vertical projections of the magnetic induction units 3a, 3b, 3c, and 3d are respectively located at the air gap positions of the magnetic flux path connection areas 2Da, 2Db, 2Dc, and 2Dd in the magnetic field conversion unit. If the magnetic induction unit is a tunnel magnetoresistance TMR as an example, since the magnetic field component at the air gap of the magnetic flux path connection areas 2Da and 2Dd is in the negative direction of the Y axis, and the magnetic field component at the air gap of the magnetic flux path connection areas 2Db and 2Dc is in the positive direction of the Y axis, the resistance values ​​of the magnetic induction units 3a and 3d increase, and the resistance values ​​of the magnetic induction units 3b and 3c decrease. Therefore, a push-pull full-bridge structure can be used to sense the magnetic field in the negative direction of the Z axis to generate a differential voltage signal. An open-loop signal conditioning circuit is used to condition, amplify, temperature compensate, and linearize the differential voltage signal to form the output signal of the current sensor.

[0078] By using two magnetic ring structures placed in parallel, the magnetic ring 20 and the bracket shell are used to form an integrated structure to gather and amplify the annular induced magnetic field of the current conductor 10 to be measured, and the magnetic conductivity of the metal soft magnetic material on the base at the embedded opening in the magnetic field conversion unit is used to form two converging and separating magnetic flux paths, and magnetic field components with opposite directions are generated at air gaps at different positions to form a differential magnetic field, thereby forming a push-pull bridge structure to achieve differential detection combining an annular iron core structure with a single sensitivity direction magnetic induction unit. Placing multiple magnetic ring structures in parallel increases the flexibility of the measurement range, and the single sensitivity direction magnetic induction unit avoids the angle deviation and zero point offset problems caused by using different sensitivity directions in the prior art, and has good sensitivity consistency, high measurement accuracy, and good stability.

[0079] In one embodiment, the magnetic field conversion unit also includes: a flux shielding soft magnetic path; the flux shielding soft magnetic path connects two flux path connection areas in a plurality of flux path connection areas that are relatively arranged along the vertical projection direction of the air gap; the flux shielding soft magnetic path is used to isolate external interference magnetic fields parallel to the sensitivity direction of the magnetic induction unit.

[0080] For example, Fig.11 As shown, the magnetic field conversion unit includes a magnetic field input area (2Aa, 2Ab), a magnetic field output area (2Ba, 2Bb), a magnetic flux direction conversion area (2Ca, 2Cb, 2Cc, 2Cd, 2Ce, 2Cf, 2Cg, 2Ch), a magnetic flux path connection area (2Da, 2Db, 2Dc, 2Dd, 2De, 2Df), and a magnetic flux shielding soft magnetic path 2E. Compared to Figure 3 The magnetic field conversion unit shown in the figure will Figure 3 The magnetic field input area 2A and the magnetic field output area 2B are symmetrically divided into magnetic field input areas 2Aa, 2Ab and magnetic field output areas 2Ba, 2Bb along the Z axis; and a flux shielding soft magnetic path 2E is introduced to connect in the Y axis direction Figure 3 The magnetic flux path connects the regions 2De and 2Db. Among them, the magnetic flux direction conversion regions 2Ca and 2Cg are corners pointing to the positive direction of the Y axis and the positive direction of the Z axis, the magnetic flux direction conversion regions 2Cb and 2Ch are corners pointing to the negative direction of the Y axis and the negative direction of the Z axis, the magnetic flux direction conversion regions 2Cc and 2Ce are corners pointing to the negative direction of the Y axis and the positive direction of the Z axis, and the magnetic flux direction conversion regions 2Cd and 2Cf are corners pointing to the positive direction of the Y axis and the negative direction of the Z axis. The magnetic flux path connection area 2Da is connected to the magnetic flux direction conversion areas 2Ca and 2Cb in the Y-axis direction; the magnetic flux path connection area 2Db includes three ports pointing to the negative direction of the Y-axis, the positive direction of the Z-axis, and the negative direction of the Z-axis, and is connected to the magnetic flux direction conversion areas 2Cb and 2Cc in the Z-axis direction; the magnetic flux path connection area 2Dc is connected to the magnetic flux direction conversion areas 2Cc and 2Cd in the Y-axis direction; the magnetic flux path connection area 2Dd is connected to the magnetic flux direction conversion areas 2Ce and 2Cf in the Y-axis direction; the magnetic flux path connection area 2De includes three ports pointing to the positive direction of the Y-axis, the positive direction of the Z-axis, and the negative direction of the Z-axis, and is connected to the flux direction conversion areas 2Cf and 2Cg in the Z-axis direction; the flux path connection area 2Df is connected to the flux direction conversion areas 2Cg and 2Ch in the Y-axis direction; the flux shielding soft magnetic path 2E is connected to the flux path connection areas 2De and 2Db in the Y-axis direction; and the flux path connection areas 2Da, 2Dc, 2Dd, and 2Df are respectively provided with two air gaps that penetrate the metal soft magnetic material along the Z-axis direction.

[0081] When the direction of the induced magnetic field passing through the opening is the negative direction of the Z axis, the metal soft magnetic material of the magnetic field conversion unit forms a magnetic flux path through magnetic conductivity, and the induced magnetic field enters from both ends of the magnetic field input area 2Aa and 2Ab. The magnetic circuit at the end of the magnetic field input area 2Aa is twisted to the positive direction of the Y axis through the magnetic flux direction conversion area 2Ca, and then passes through the magnetic flux path connection area 2Da with an air gap, and generates a magnetic field component in the positive direction of the Y axis in the air gap; then it passes through the magnetic flux direction conversion area 2Cb, the magnetic flux path connection area 2Db, and the magnetic flux direction conversion area 2Cc in turn, and the magnetic circuit is twisted from the positive direction of the Y axis to the negative direction of the Y axis, and then passes through the magnetic flux path connection area 2Dc with an air gap, and generates a magnetic field component in the negative direction of the Y axis in the air gap; finally, the magnetic circuit is twisted back to the negative direction of the Z axis through the magnetic flux direction conversion area 2Cd, and then passes through the magnetic field output area 2Ba. The magnetic circuit at the end of the magnetic field input area 2Ab is twisted to the negative direction of the Y axis through the magnetic flux direction conversion area 2Ce, and then passes through the magnetic flux path connection area 2Dd with an air gap, and generates a magnetic field component in the negative direction of the Y axis in the air gap; then it passes through the magnetic flux direction conversion area 2Cf, the magnetic flux path connection area 2De, and the magnetic flux direction conversion area 2Cg in turn, and the magnetic circuit is twisted from the negative direction of the Y axis to the positive direction of the Y axis, and then passes through the magnetic flux path connection area 2Df with an air gap, and generates a magnetic field component in the positive direction of the Y axis in the air gap; finally, the magnetic circuit is twisted back to the negative direction of the Z axis through the magnetic flux direction conversion area 2Ch, and then passes through the magnetic field output area 2Bb. In this way, the induced magnetic field in the negative direction of the Z axis can generate opposite magnetic field components in the positive and negative directions of the Y axis at air gaps at different positions, forming a differential magnetic field. Fig.12 As shown, from Fig.11 It can be seen from the simulation diagram of the magnetic flux path after the magnetic field conversion unit is added with the negative magnetic field of the Z axis that the induced magnetic field along the negative direction of the Z axis is gathered and amplified by the metal soft magnetic material, and twisted from both sides to the positive direction of the Y axis and the negative direction of the Y axis to form two magnetic flux paths in parallel; then the two magnetic paths are twisted in the Y axis direction and then twisted back to the positive direction of the Z axis. It can be seen that the magnetic flux path of the induced magnetic field is subjected to a magnetic permeability offset of 0-90 degrees in a spatial solid angle according to the structure of the magnetic flux direction conversion zone, and a component parallel to the XY plane is generated at the air gap of the magnetic flux path connection area 2Da, 2Dc, 2Dd, and 2Df. Specifically, an obvious magnetic field component in the positive direction of the Y axis can be generated at the air gap of the magnetic flux path connection area 2Da and 2Df, and an obvious magnetic field component in the negative direction of the Y axis can be generated at the air gap of the magnetic flux path connection area 2Dc and 2Dd. In particular, the magnetic flux shielding soft magnetic path 2E is introduced to make the magnetic circuit formed by the external interference magnetic field parallel to the sensitivity direction of the magnetic induction unit away from the location of the air gap, thereby restoring the measurement range. In addition, the magnetic field input area 2A and the magnetic field output area 2B are symmetrically divided into magnetic field input areas 2Aa, 2Ab and magnetic field output areas 2Ba, 2Bb along the Z axis, which produces an isolation effect and further strengthens the shielding. Fig.13As shown, from the simulation diagram of the magnetic flux path after the magnetic field conversion unit is added with the Y-axis magnetic field, it can be seen that the flux shielding soft magnetic path 2E concentrates magnetism in the sensitivity direction of the magnetic induction unit, and most of the external magnetic field along the Y-axis direction forms a magnetic circuit in the Y-axis direction along the flux shielding soft magnetic path 2E, shielding the external interference magnetic field in the sensitivity direction of the air gap.

[0082] Among them, the sensitivity directions of the magnetic induction units 3a, 3b, 3c, and 3d can all be in the positive direction of the Y axis, and the vertical projections of the magnetic induction units 3a, 3b, 3c, and 3d are respectively located at the air gap positions of the magnetic flux path connection areas 2Da, 2Dc, 2Dd, and 2Df in the magnetic field conversion unit, so the resistance values ​​of the magnetic induction units 3a and 3d are reduced, and the resistance values ​​of the magnetic induction units 3b and 3c are increased. Therefore, a push-pull full-bridge structure can be used to sense the magnetic field in the negative direction of the Z axis to generate a differential voltage signal. An open-loop signal conditioning circuit is used to condition, amplify, temperature compensate, and linearize the differential voltage signal to form the output signal of the current sensor.

[0083] By introducing a flux-shielded soft magnetic path, the magnetic field input area and the magnetic field output area are separated, and the external interference magnetic field in the sensitivity direction of the air gap is shielded, further enhancing the measurement accuracy and measurement range and improving the anti-interference ability.

[0084] In one embodiment, the magnetic field conversion unit also includes: a magnetic flux path connection area; the magnetic flux path connection area is located between two magnetic flux direction conversion areas relatively arranged along the vertical projection direction of the air gap among the multiple magnetic flux direction conversion areas; the magnetic flux path connection area is used to divide the differential magnetic field generated at the air gap.

[0085] For example, Fig.14As shown, the magnetic field conversion unit includes a magnetic field input area (2Aa, 2Ab), a magnetic field output area (2Ba, 2Bb), a magnetic flux direction conversion area (2Ca, 2Cb, 2Cc, 2Cd, 2Ce, 2Cf, 2Cg, 2Ch), a magnetic flux path connection area (2Da, 2Db, 2Dc, 2Dd, 2De, 2Df), a magnetic flux shielding soft magnetic path (2Ea, 2Eb), and a magnetic flux path connection area (2Fa, 2Fb). Among them, the magnetic flux direction conversion area 2Ca, 2Cg is a corner pointing to the negative direction of the Y axis and the positive direction of the Z axis, the magnetic flux direction conversion area 2Cb, 2Ch is a corner pointing to the positive direction of the Y axis and the negative direction of the Z axis, the magnetic flux direction conversion area 2Cc, 2Ce is a corner pointing to the positive direction of the Y axis and the positive direction of the Z axis, and the magnetic flux direction conversion area 2Cd, 2Cf is a corner pointing to the negative direction of the Y axis and the negative direction of the Z axis. The magnetic flux path connection area 2Da is connected to the magnetic flux direction conversion areas 2Ca and 2Cb in the Y-axis direction, the magnetic flux path connection area 2Db is connected to the magnetic flux direction conversion areas 2Cb and 2Cc in the Z-axis direction, the magnetic flux path connection area 2Dc is connected to the magnetic flux direction conversion areas 2Cc and 2Cd in the Y-axis direction, the magnetic flux path connection area 2Dd is connected to the magnetic flux direction conversion areas 2Ce and 2Cf in the Y-axis direction, the magnetic flux path connection area 2De is connected to the magnetic flux direction conversion areas 2Cf and 2Cg in the Z-axis direction, and the magnetic flux path connection area 2Df is connected to the magnetic flux direction conversion areas 2Cg and 2Ch in the Y-axis direction. The magnetic flux shielding soft magnetic path 2Ea is connected to the magnetic field input areas 2Aa and 2Ab in the Y-axis direction, and the magnetic flux shielding soft magnetic path 2Eb is connected to the magnetic field output areas 2Ba and 2Bb in the Y-axis direction. The magnetic flux path connection area 2Fa is located between the magnetic flux direction conversion areas 2Ca and 2Cd, and the magnetic flux path connection area 2Fb is located between the magnetic flux direction conversion areas 2Ce and 2Ch. The magnetic flux path connection areas 2Da, 2Dc, 2Dd, and 2Df are respectively provided with two air gaps penetrating the metal soft magnetic material along the Z-axis direction.

[0086] When the direction of the induced magnetic field passing through the opening is the negative direction of the Z axis, the metal soft magnetic material of the magnetic field conversion unit forms a magnetic flux path through magnetic conductivity, and the induced magnetic field enters from both ends of the magnetic field input area 2Aa and 2Ab. For the magnetic circuit at the end of the magnetic field input area 2Aa, a part of it enters the magnetic flux direction conversion area 2Cd directly from the magnetic flux direction conversion area 2Ca along the negative direction of the Z axis by the magnetic conductivity of the magnetic flux path connection area 2Fa, and the other part is twisted to the negative direction of the Y axis by the magnetic flux direction conversion area 2Ca and passes through the magnetic flux path connection area 2Da with an air gap, and generates a magnetic field component in the negative direction of the Y axis in the air gap; then, it passes through the magnetic flux direction conversion area 2Cb, the magnetic flux path connection area 2Db, and the magnetic flux direction conversion area 2Cc in turn, and the magnetic circuit is twisted from the negative direction of the Y axis to the positive direction of the Y axis, and then passes through the magnetic flux path connection area 2Dc with an air gap, and generates a magnetic field component in the positive direction of the Y axis in the air gap; finally, the magnetic circuit is twisted back to the negative direction of the Z axis through the magnetic flux direction conversion area 2Cd and passes through the magnetic field output area 2Ba. For the magnetic circuit at the end of the magnetic field input area 2Ab, a part of it enters the magnetic flux direction conversion area 2Ch directly from the magnetic flux direction conversion area 2Ce along the negative direction of the Z axis due to the magnetic conductivity of the magnetic flux path connection area 2Fb, and the other part is twisted to the positive direction of the Y axis by the magnetic flux direction conversion area 2Ce and passes through the magnetic flux path connection area 2Dd with an air gap, and generates a magnetic field component in the positive direction of the Y axis in the air gap; then it passes through the magnetic flux direction conversion area 2Cf, the magnetic flux path connection area 2De, and the magnetic flux direction conversion area 2Cg in turn, and the magnetic circuit is twisted from the positive direction of the Y axis to the negative direction of the Y axis, and then passes through the magnetic flux path connection area 2Df with an air gap, and generates a magnetic field component in the negative direction of the Y axis in the air gap; finally, the magnetic circuit is twisted back to the negative direction of the Z axis through the magnetic flux direction conversion area 2Ch and passes through the magnetic field output area 2Bb. In this way, the induced magnetic field in the negative direction of the Z axis can generate opposite magnetic field components in the positive and negative directions of the Y axis at air gaps at different positions, forming a differential magnetic field. Fig.15 As shown, from Fig.14It can be seen from the simulation diagram of the magnetic flux path after the magnetic field conversion unit is added with the negative magnetic field of the Z axis: the induced magnetic field along the negative direction of the Z axis is gathered and amplified by the metal soft magnetic material to form a symmetrical magnetic circuit on both sides, and the magnetic circuits on both sides generate magnetic division. A part of the magnetic circuits on both sides is still directly output along the negative direction of the Z axis, and twisted from both sides to the positive direction of the Y axis and the negative direction of the Y axis to form two magnetic flux paths in parallel, and then twisted in the Y axis direction and then twisted back to the positive direction of the Z axis. It can be seen that an obvious magnetic field component in the negative direction of the Y axis can be generated at the air gaps in the magnetic flux path connection areas 2Da and 2Df, and an obvious magnetic field component in the positive direction of the Y axis can be generated at the air gaps in the magnetic flux path connection areas 2Dc and 2Dd. The magnitude of the magnetic field at the above air gaps is weakened due to magnetic division, so the magnitude of the magnetic field passing through the air gap can be controlled to adjust the measurement range. In particular, the function of the magnetic flux shielding soft magnetic paths 2Ea and 2Eb is also to keep the magnetic circuit formed by the external interference magnetic field parallel to the sensitivity direction of the magnetic induction unit away from the location of the air gap. As shown in FIG. Fig.16 As shown, from the magnetic flux path simulation diagram after the magnetic field conversion unit is added with the Y-axis direction magnetic field, it can be seen that the flux shielding soft magnetic paths 2Ea and 2Eb each concentrate magnetism in the sensitivity direction of the magnetic induction unit, and most of the external magnetic field along the Y-axis direction forms a magnetic circuit in the Y-axis direction along the flux shielding soft magnetic paths 2Ea and 2Eb, shielding the external interference magnetic field in the sensitivity direction of the air gap.

[0087] Among them, the sensitivity directions of the magnetic induction units 3a and 3b can both be in the positive direction of the Y axis, and the vertical projections of the magnetic induction units 3a and 3b are respectively located at the air gap positions of the magnetic flux path connection areas 2Da and 2Dc in the magnetic field conversion unit, so the resistance value of the magnetic induction unit 3a increases, and the resistance value of the magnetic induction unit 3b decreases. Therefore, a push-pull half-bridge structure can be used to sense the magnetic field in the negative direction of the Z axis to generate a differential voltage signal.

[0088] By using the induced magnetic field to generate magnetic field components with opposite directions at different air gaps, a differential magnetic field is formed, thereby forming a push-pull bridge structure. The introduction of the magnetic flux path connection area can regulate the magnetic field size at the air gap, further controlling the measurement range and broadening the application occasions.

[0089] In one embodiment, at least two magnetic induction units of the magnetic current sensor 01 are correspondingly arranged at at least two air gap positions on one side along the direction from the magnetic field input area to the magnetic field output area.

[0090] For example, please refer to Fig.14 , along the two magnetic flux paths from the magnetic field input area to the magnetic field output area, magnetic induction units 3a and 3b are only arranged in the air gap of the metal soft magnetic material on the left magnetic flux path, that is, on the positive direction of the Y axis, which is different from the half-bridge structure formed by only using magnetic induction units 3a and 3b. Figure 6Compared with the single magnetic flux path shown in FIG. 1 , the magnetic field at the magnetic induction units 3a and 3b can be regarded as being weakened by approximately half by the magnetic distribution of the metal soft magnetic material on the negative side of the Y axis of the magnetic induction module, so it can be compared with Fig.14 The magnetic flux path connection areas 2Fa and 2Fb in the magnetic flux path achieve similar effects, and the measurement range is adjusted by magnetic flux division. By setting at least two magnetic induction units on one side of a single magnetic flux path, a magnetic flux division effect can be generated to adjust the magnetic field size at the air gap, further control the measurement range, and broaden the application occasions.

[0091] In one embodiment, the magnetic field conversion unit and at least two magnetic induction units are arranged on a circuit chip using a chip integration process, and the circuit chip is placed at an opening position of the magnetic ring structure.

[0092] Exemplarily, the magnetic field conversion unit and the magnetic induction unit can be located on the same circuit chip, and the chip can be placed in the opening of the magnetic focusing ring 20. Since the sensitivity directions of all magnetic induction units are in the same direction, when the sensitivity direction of the selected magnetic induction unit is parallel to the plane where it is located (such as TMR, AMR, GMR, etc.), a single chip integration preparation process can be used to achieve one-time single chip preparation. The magnetic field conversion unit is composed of a metal soft magnetic material with high magnetic permeability, and the metal soft magnetic material is deposited on the substrate inside the circuit chip. The magnetic focusing ring 20 with a single or multiple magnetic ring structures gathers and amplifies the induced magnetic field. The magnetic field conversion unit and the magnetic induction unit are located on the same circuit chip placed in the opening of the magnetic focusing ring 20. The metal soft magnetic material deposited on the substrate in the magnetic field conversion unit in the chip forms two parallel magnetic flux paths through magnetic conduction, and generates magnetic field components with opposite directions at air gaps at different positions to form a differential magnetic field, thereby being able to form a push-pull bridge structure. By using a single chip integration preparation process to process the magnetic field conversion unit and the magnetic induction unit on the same chip, the cost is reduced.

[0093] In one embodiment, the magnetic flux direction conversion region and the magnetic flux path connection region of the magnetic field conversion unit share a regular metallic soft magnetic material rectangular structure.

[0094] For example, for the listed Figure 3 , Figure 6 , Figure 8 , Fig.11 , Fig.14The magnetic current sensor 01 composed of structures such as, the magnetic field input area and the magnetic field output area of ​​the magnetic field conversion unit can be interchanged according to the direction change of the induced magnetic field passing through the opening, that is, for the same magnetic field conversion unit metal soft magnetic material structure, the magnetic field input area and the magnetic field output area are only used to indicate and describe the direction of the induced magnetic field entering and exiting the magnetic field conversion unit; when the induced magnetic field is reversed, it can be regarded as the original magnetic field input area and magnetic field output area are interchanged. There is an interconnected relationship between the magnetic field input area, the magnetic field output area, the magnetic flux direction conversion area, and the magnetic flux path connection area in the magnetic field conversion unit. In actual production, the interconnected areas actually share the same piece of metal soft magnetic material rather than independent metal soft magnetic materials; therefore, for the metal soft magnetic material structure of the same magnetic field conversion unit, there may be multiple ways of definition when describing it; according to actual conditions, the part of the metal soft magnetic material with an air gap can be regarded as being located in the magnetic flux path connection area in addition to being regarded as being located in the magnetic flux direction conversion area. However, all the definition methods are different from the description methods when describing the structure of this application in a schematic manner, and have no impact on the actual structure and technical features of this application.

[0095] In actual production, the shape of the metal soft magnetic material constituting the magnetic field conversion unit can be adjusted and simplified without changing the measurement principle. At this time, the irregular metal soft magnetic material shared by the magnetic flux direction conversion area and the magnetic flux path connection area in the magnetic field conversion unit will be correspondingly simplified to a regular shape such as a rectangle. Fig.17 As shown, Figure 3 The metal soft magnetic material in the medium magnetic field conversion unit can be replaced by Fig.17 The advantage of replacing the metal soft magnetic material structure shown in (a) is that the process difficulty and cost are reduced, especially the excessively high requirements for equipment precision when using a single chip integration preparation process. Figure 6 , Figure 8 , Fig.11 , Fig.14 The metal soft magnetic materials of the magnetic field conversion unit in can be replaced by Fig.17 The metal soft magnetic material structures shown in (c), (b), (d), and (e). In particular, Figure 3 , Figure 6 , Figure 8 , Fig.11 , Fig.14 In the magnetic current sensor 01 composed of the same structure, each magnetic circuit generated by the induced magnetic field in the magnetic field conversion unit is reversed at most once in the sensitivity direction of the magnetic induction unit, for example Figure 6 The magnetic field is twisted from the positive direction of the Y axis to the negative direction of the Y axis to form a differential magnetic field. The irregular metal soft magnetic material shared by the magnetic flux direction conversion area and the magnetic flux path connection area in the magnetic field conversion unit is simplified to a regular shape such as a rectangle, thereby reducing the process difficulty and cost.

[0096] In one embodiment, the magnetic flux direction conversion area and the magnetic flux path connection area of ​​the magnetic field conversion unit are formed by a rectangular structure of a metallic soft magnetic material with multiple inversions.

[0097] For example, Fig.18 As shown, the magnetic field conversion unit can adopt a multiple reverse structure according to actual needs, for example, Fig.17 The structure shown in (a) (i.e. Figure 3 The structure in the figure is repeatedly extended along the Z axis to form Fig.18 The structure shown in (a) is Fig.18 The metal soft magnetic material of the repeated extension part of the structure shown in (a) has a magnetic flux path generated by the internal magnetic conduction deviation and magnetic circuit distortion due to the repeated structure shape. Fig.17 The principle of generating the magnetic flux path of the structure shown in (a) is the same, and the same differential magnetic field is formed in the sensitivity direction of the magnetic induction unit, which will not be repeated here. Fig.18 (b) and Fig.18 In (c), they are Fig.17 (b) and Fig.17 A metal soft magnetic material structure formed by repeated extension along the Z-axis direction based on the structure shown in (c).

[0098] Similarly, Figure 3 and Figure 6 Only one magnetic field input area and magnetic field output area are used. Figure 8 , Fig.11 , Fig.14 Two parallel magnetic field input areas and magnetic field output areas are used, so one and two series-parallel magnetic circuits are generated respectively when entering and exiting the magnetic field conversion unit. Therefore, the magnetic field conversion unit can use multiple magnetic field input areas and multiple magnetic field output areas to form multiple magnetic circuits according to actual needs. For example, Fig.17 Middle (a), Fig.17 Based on the structure shown in (b), it is repeatedly extended along the X-axis or Y-axis direction to form Fig.18 Middle (d), Fig.18 For the structure shown in (e) in FIG. Fig.18 (e) The metal soft magnetic material of the repeated extension part has a repeated structure shape, and the magnetic flux path generated by the internal magnetic conduction deviation and magnetic circuit distortion is different from Fig.18 Middle (a), Fig.18 The principle of generating the magnetic flux path in (b) is the same and will not be repeated here. By using multiple reversed rectangular structures of metal soft magnetic materials to form a magnetic field conversion unit, various forms of series-parallel magnetic circuits can be formed, which are suitable for magnetic sensors with various functions, expanding the scope of application and improving practicality.

[0099] In one embodiment, the differential detection module 40 includes: an open-loop signal conditioning circuit; the open-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the open-loop signal conditioning circuit is used to condition, amplify, temperature compensate and linearize the differential voltage signal.

[0100] Exemplarily, the magnetic induction unit can use giant magnetic impedance GMI, fluxgate Fluxgate, Hall element Hall, anomalous Hall element AHE or magnetoresistive sensitive element according to different placement positions and directions; wherein the magnetoresistive sensitive element can be one or more anisotropic magnetoresistor AMR, giant magnetoresistor GMR, tunnel magnetoresistor TMR, vertical tunnel magnetoresistor PTMR and giant magnetoresistor CMR connected in series and parallel. Specifically, when the sensitivity direction of the magnetic induction unit is perpendicular to the plane where it is located, the substrate where the magnetic induction unit is located is perpendicular to the plane where the magnetic field conversion unit is located. For example, if the magnetic field conversion unit located in the YZ plane selects a Hall element for measurement, then each substrate where the Hall element is located is parallel to the XZ plane, and then the current sensor is formed by the basic components such as the substrate, the lead pad, the mechanical bracket shell and the annular iron core, wherein the open-loop signal conditioning circuit is arranged on the substrate. The open-loop signal conditioning circuit is used to condition, amplify, temperature compensate and linearize the differential voltage signal to form the output signal of the current sensor. When the sensitivity direction of the magnetic induction unit is parallel to the plane where it is located, the substrate where it is located is parallel to the plane where the magnetic field conversion unit is located. Since all magnetic induction units can form a differential bridge or a push-pull bridge with only the sensitivity in the same direction, when a magnetic induction unit whose sensitivity is parallel to the plane in which it is located is used, such as a tunnel magnetoresistance TMR, it can be prepared at one time, and the magnetic current sensor 01 is formed by combining the annular iron core structure magnetic field ring 20, the magnetic field conversion unit, and the open-loop signal conditioning circuit. By using the open-loop signal conditioning circuit for conditioning and amplification, temperature compensation and linearity correction, open-loop detection is realized, the detection accuracy is improved, and good linearity is achieved.

[0101] In one embodiment, the differential detection module 40 includes: a closed-loop signal conditioning circuit and a magnetic field feedback coil 41; the closed-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the closed-loop signal conditioning circuit, the magnetic field feedback coil 41 and the magnetic induction unit constitute a closed-loop magnetic field feedback structure; the closed-loop signal conditioning circuit is used to condition and amplify the differential voltage signal; the magnetic field feedback coil 41 is used to generate a feedback magnetic field according to the conditioned and amplified signal to achieve dynamic balance of the magnetic field, and sample the current in the magnetic field feedback coil to form an electrical signal to be measured.

[0102] Exemplarily, the differential detection module 40 as an output can use a closed-loop signal conditioning circuit and a magnetic field feedback coil 41, wherein the closed-loop signal conditioning circuit, the magnetic field feedback coil 41 and the magnetic induction unit constitute a closed-loop magnetic field feedback structure. After the differential voltage signal is amplified by the closed-loop signal conditioning circuit, a feedback magnetic field is generated by the magnetic field feedback coil 41 to achieve a dynamic balance of the magnetic field. After sampling the current in the magnetic field feedback coil 41, an output signal of the current sensor (electrical signal to be measured) can be formed. By using a closed-loop signal conditioning circuit and a magnetic field feedback coil 41 for differential detection, closed-loop negative feedback is achieved, accuracy is improved, and good linearity is achieved.

[0103] In one embodiment, the magnetic field feedback coil 41 is located inside the magnetic induction unit, inside the circuit chip, passes through the magnetic focusing ring 20 , or surrounds the magnetic focusing ring 20 .

[0104] For example, the magnetic field feedback coil 41 may be located inside the magnetic induction unit or inside the circuit chip to generate feedback current. Fig.19 As shown, the magnetic field feedback coil 41 can also directly pass through the magnetic focusing ring 20 or wrap around the magnetic focusing ring 20. It can be seen that the direction of the internal current of the magnetic field feedback coil 41 passing through the magnetic focusing ring 20 (negative direction of the Y axis, perpendicular to the paper and outward) is opposite to the direction of the current conductor 10 to be measured (positive direction of the Y axis, perpendicular to the paper and inward). Therefore, the induced magnetic field generated is counterclockwise and clockwise, and the two generate induced magnetic fields in the positive and negative directions of the Z axis at the opening, respectively, thereby offsetting each other to achieve dynamic balance of the magnetic field. The internal current direction of the magnetic field feedback coil 41 wrapped around the magnetic focusing ring 20 is as shown in FIG. Fig.19 As shown by the middle arrow, a counterclockwise magnetic field is directly generated in the magnetic focusing ring 20, which can also offset the clockwise induced magnetic field generated by the current conductor 10 to be measured to achieve a dynamic balance of the magnetic field. If a single chip integrated manufacturing process is used, the magnetic field feedback coil 41 can be located inside the magnetic induction unit or inside the circuit chip, or it can directly pass through the magnetic focusing ring 20 or surround the magnetic focusing ring 20. By using a closed-loop signal conditioning circuit and a magnetic field feedback coil 41 for differential detection, closed-loop negative feedback is achieved. The magnetic field feedback coil 41 can be located inside the magnetic induction unit, inside the circuit chip, or directly pass through the magnetic focusing ring 20 or surround the magnetic focusing ring 20, thereby improving the negative feedback efficiency.

[0105] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0106] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A magnetic current sensor, characterized in that: The sensor comprises: a current conductor to be measured, a magnetic focusing ring, a differential magnetic field generating module and a differential detection module; the magnetic focusing ring comprises a magnetic ring structure with an opening; the current conductor to be measured passes through a hollow area of ​​the magnetic ring structure; the differential magnetic field generating module is located at the opening position of the magnetic ring structure; the differential detection module is electrically connected to the differential magnetic field generating module; The differential magnetic field generation module comprises: a magnetic field conversion unit and at least two magnetic induction units; the magnetic field conversion unit is connected to the magnetic ring structure with an opening to form a closed magnetic flux path; the magnetic induction unit is located at the air gap of the magnetic field conversion unit, and the sensitivity direction of the magnetic induction unit is perpendicular to the vertical projection direction of the air gap; Among them, the magnetic focusing ring is used to concentrate and amplify the induced magnetic field generated by the current conductor to be measured; the magnetic field conversion unit is used to conduct the concentrated and amplified induced magnetic field to the magnetic flux path, and generate a differential magnetic field component in the air gap of the magnetic flux path; the magnetic induction unit is used to generate a differential voltage signal according to the differential magnetic field component; the differential detection module is used to process the differential voltage signal and output the electrical signal to be measured.

2. The sensor according to claim 1, characterized in that The magnetic focusing ring comprises: a single magnetic ring structure with an opening; the magnetic field conversion unit comprises: a magnetic field input area, a magnetic field output area, a plurality of magnetic flux direction conversion areas and a plurality of magnetic flux path connection areas; the plurality of magnetic flux path connection areas comprise: at least two air gaps located at different positions; the at least two magnetic induction units are correspondingly arranged at the positions of the at least two air gaps; The magnetic field input area is connected to one end of the opening; the magnetic field output area is connected to the other end of the opening; the magnetic flux direction conversion area is located in the corner area of ​​the magnetic field conversion unit, and the magnetic flux path connection area connects two adjacent corner areas and forms a closed magnetic flux path with the magnetic field input area and the magnetic field output area.

3. The sensor according to claim 2, characterized in that in, The differential magnetic field generation module further includes: a magnetic shielding reference magnetic induction unit and an external magnetic field reference magnetic induction unit; The magnetic shielding reference magnetic induction unit is located within the vertical projection range of the magnetic field conversion unit; the external magnetic field reference magnetic induction unit is located outside the vertical projection range of the magnetic field conversion unit; The at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the induced magnetic field to generate a differential voltage signal; or The at least two magnetic induction units and the external magnetic field reference magnetic induction unit are used to form a magnetic resistor of a differential half-bridge or differential full-bridge structure circuit, and sense the induced magnetic field to generate a differential voltage signal; or At least one of the magnetic induction units and the magnetic shielding reference magnetic induction unit is used to form a magnetic resistance of a differential half-bridge or differential full-bridge structure circuit, and sense the induced magnetic field to generate a differential voltage signal.

4. The sensor according to claim 1, characterized in that The magnetic focusing ring comprises: at least two magnetic ring structures with openings; the at least two magnetic ring structures are placed side by side along the direction of the current conductor to be measured; the magnetic field conversion unit comprises: at least two magnetic field input areas, at least two magnetic field output areas, multiple magnetic flux direction conversion areas and multiple magnetic flux path connection areas; the multiple magnetic flux path connection areas comprise: at least two air gaps located at different positions; the at least two magnetic induction units are correspondingly arranged at the positions of the at least two air gaps; The magnetic field input area is connected to one end of the opening; the magnetic field output area is connected to the other end of the opening; the magnetic flux direction conversion area is located in the corner area of ​​the magnetic field conversion unit, and the magnetic flux path connection area connects two adjacent corner areas and forms a closed magnetic flux path with the magnetic field input area and the magnetic field output area; The at least two magnetic induction units are used to form a magnetic resistance of a push-pull half-bridge or push-pull full-bridge structure circuit, and sense the induced magnetic field to generate a differential voltage signal.

5. The sensor according to claim 4, characterized in that in, The magnetic field conversion unit further includes: a magnetic flux shielding soft magnetic path; The flux-shielding soft magnetic path connects two flux path connection areas among the multiple flux path connection areas that are relatively arranged along the vertical projection direction of the air gap; the flux-shielding soft magnetic path is used to isolate external interference magnetic fields parallel to the sensitivity direction of the magnetic induction unit.

6. The sensor according to claim 5, characterized in that The magnetic field conversion unit further includes: a magnetic flux path connection area; The magnetic flux path connection area is located between two magnetic flux direction conversion areas that are relatively arranged along the vertical projection direction of the air gap among the multiple magnetic flux direction conversion areas; the magnetic flux path connection area is used to divide the differential magnetic field generated at the air gap.

7. The sensor according to claim 5, characterized in that The at least two magnetic induction units are correspondingly arranged at at least two air gap positions on one side along the direction from the magnetic field input area to the magnetic field output area.

8. The sensor according to any one of claims 1 to 7, characterized in that: The magnetic field conversion unit and the at least two magnetic induction units are arranged on a circuit chip by using a chip integration process, and the circuit chip is placed at an opening position of the magnetic ring structure.

9. The sensor according to any one of claims 2 to 7, characterized in that: The magnetic flux direction conversion area and the magnetic flux path connection area share a regular metallic soft magnetic material rectangular structure.

10. The sensor according to any one of claims 2 to 7, characterized in that: The magnetic flux direction conversion area and the magnetic flux path connection area are formed by a rectangular structure of a metallic soft magnetic material with multiple inversions.

11. The sensor according to any one of claims 1 to 7, characterized in that: The differential detection module includes: an open-loop signal conditioning circuit; the open-loop signal conditioning circuit is electrically connected to the magnetic induction unit; The open-loop signal conditioning circuit is used to condition, amplify, temperature compensate and perform linearity correction on the differential voltage signal.

12. The sensor according to any one of claims 1 to 7, characterized in that: The differential detection module comprises: a closed-loop signal conditioning circuit and a magnetic field feedback coil; the closed-loop signal conditioning circuit is electrically connected to the magnetic induction unit; the closed-loop signal conditioning circuit, the magnetic field feedback coil and the magnetic induction unit form a closed-loop magnetic field feedback structure; The closed-loop signal conditioning circuit is used to condition and amplify the differential voltage signal; the magnetic field feedback coil is used to generate a feedback magnetic field according to the conditioned and amplified signal to achieve a dynamic balance of the magnetic field, and to sample the current in the magnetic field feedback coil to form the electrical signal to be measured.

13. The sensor according to claim 12, characterized in that in, The magnetic field feedback coil is located inside the magnetic induction unit, inside the circuit chip, passes through the magnetic focusing ring, or surrounds the magnetic focusing ring.

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