Current sensor without magnetic core

Abstract

The invention provides a current sensor without a magnetic core. The current sensor comprises an inverted cylindrical magnetic shielding body, an electric field shielding body, a diversion body, a magnetic field gradient sensing module and a signal processing module. By optimizing the structural design of the current conductor, the magnetic field gradient in the sensing direction of the magnetic field gradient sensing module by the current flowing through the current conductor is constructed or increased. And meanwhile, the magnetic shielding body and the electric field shielding structure which are arranged in a nested manner are utilized to form a three-dimensional anti-electromagnetic interference capability, so that the measurement precision, the working stability and the reliability of the current sensor are further improved. The current sensor provided by the invention has the advantages of small size, simple process, wide measuring range, high measurement precision, high frequency response and the like by laminating, nesting and assembling related parts under the condition of no magnetic core, and can well adapt to the special requirements of a future current precision measurement scene on the miniaturization and high frequency response of the current sensor.

Description

Technical Field

[0001] The technical solution provided by this application relates to the field of current measurement, and specifically relates to a current sensor without a magnetic core. Background Art

[0002] Currently, common current measurement devices on the market can be classified into shunts, open-loop current sensors, closed-loop current sensors, and fluxgate current sensors according to their working methods. Current sensors can be divided into chip-level current sensors and current sensors assembled with components according to their manufacturing processes.

[0003] The above various current measurement devices have their own advantages and disadvantages: Shunts have problems such as non-isolation, poor temperature characteristics, and poor high-frequency characteristics. Although open-loop current sensors have built-in isolation and low cost, the eddy current effect of the ferromagnetic core results in poor high-frequency characteristics. Closed-loop current sensors and fluxgate current sensors have advantages such as high precision and good linearity, but due to the built-in magnetic core, similar to open-loop current sensors, they have poor high-frequency performance. And their built-in coils result in a large volume of the sensor. Chip-level current sensors have a small volume, low price, and good high-frequency characteristics, but they cannot solve the problem of overcurrent self-heating and are generally used for small current detection. Considering that current measurement devices need to be equipped with additional electromagnetic interference-resistant components, it is difficult for current measurement devices to have the characteristics of small volume, good high-frequency response, strong anti-interference ability, and simple manufacturing / assembly process. Summary of the Invention

[0004] Aiming at the above deficiencies of existing current measurement devices, this application redesigns the components of the current sensor and the current detection method (components) without using a magnetic core, and realizes assembly in a stacked and nested manner, making the current sensor have the advantages of small volume, wide range (suitable for measuring large currents), strong anti-electromagnetic interference ability, and simple assembly process.

[0005] The non-magnetic-core current sensor provided by this application includes: a magnetic shielding body in an inverted cylindrical shape, a current conductor, a magnetic field gradient sensing module, and a signal processing module. The current conductor is disposed inside the magnetic shielding body. Taking the direction from the barrel mouth to the barrel bottom of the magnetic shielding body as the Y-axis direction, the projection of the current conductor on the YX plane is in a "Ji" shape or an inverted "U" shape, and the opening direction of the "Ji" shape or the inverted "U" shape is anti-parallel to the Y-axis direction. There is at least one notch group on at least one of the first current-conducting section, the second current-conducting section, and the third current-conducting section of the current conductor, and the at least one notch group is used to enhance / construct the magnetic field gradient signal sensed by the gradient sensing module; the first current-conducting section and the third current-conducting section are parallel and non-collinear, and one end of the second current-conducting section is connected to the first current-conducting section and the other end is connected to the third current-conducting section. The signal processing module calculates the magnitude of the current flowing through the current conductor based on the output signal of the magnetic field gradient sensing module.

[0006] Furthermore, the projection of the gradient sensing module onto the YX plane is located inside the "U"-shaped or inverted "U"-shaped projection of the guide fluid. The current sensor also includes an electric field shielding structure, the projection of which onto the YX plane is located inside the "U"-shaped or inverted "U"-shaped projection of the guide fluid onto the YX plane. The magnetic field gradient sensing module and the signal processing module are mounted on the same circuit board. The electric field shielding structure uses a non-magnetic metal material to encapsulate the magnetic field gradient sensing module, the signal processing module, and related traces on the circuit board, and provides notches to lead out signal leads.

[0007] The magnetic shield, fluid conductor, magnetic field gradient sensing module, and signal processing module of the aforementioned current sensor are nested in a layered manner. This simplifies the assembly process of the current sensor. The inherent anti-magnetic interference capability of the gradient sensor, combined with the magnetic shielding capability of the magnetic shield, gives the current sensor excellent anti-interference ability. Considering that the internal magnetic field gradient of a small-volume current sensor may not be significant, the magnetic field gradient sensed by the magnetic field gradient sensing module is increased / constructed by slotting the fluid conductor.

[0008] Furthermore, the gradient sensing module includes two identical magnetic field sensing units, and its output signal is generated based on the sensing signals of the two magnetic field sensing units; the sensing direction of the two magnetic field sensing units is the Z-axis direction or antiparallel to the Z-axis direction.

[0009] In some embodiments, the projection of the sensing center of the first magnetic field sensing unit onto the guide section of one of the slot groups falls within the range of that slot group, while the projection of the sensing center of the second magnetic field sensing unit onto the guide section of one of the slot groups falls outside the range of that slot group. Preferably, the sensing centers of the two magnetic field sensing units are arranged along the Y-axis.

[0010] Preferably, the sensing center of the first magnetic field sensing unit is located on the center plane of at least one slot of the slot group, and the center plane is perpendicular to the current direction in the current guide section where the at least one slot is located. In one embodiment, the slots of the at least one slot group are disposed on one side of the current guide section. In another embodiment, the slots of the at least one slot group are disposed on two opposite sides of the current guide section.

[0011] Furthermore, the first magnetic field sensing unit and the second magnetic field sensing unit are each composed of a plurality of magnetic sensing units connected in series or in parallel. Obviously, the spatial position of the magnetic sensing units is relatively free, as long as the magnetic fields sensed by each of the two magnetic field sensing units have a difference that meets the measurement requirements. Preferably, the magnetic sensing units of the first magnetic field sensing unit are all located on a first plane parallel to the XZ plane, and the magnetic sensing units of the second magnetic field sensing unit are all located on a second plane parallel to the XZ plane. All magnetic sensing units are identical, and the first plane does not coincide with the second plane.

[0012] Furthermore, the electric field shielding structure includes a copper-clad layer on the back of the circuit board and an electric field shielding plate. The magnetic field gradient sensing module and the signal processing module are disposed on the front side of the circuit board. At least one of the front side of the circuit board or the front side of the electric field shielding plate is provided with a solderable shielding ring, which has lead-out notches for signal leads. After the front side of the circuit board is attached to the front side of the electric field shielding plate and soldered through the solderable shielding ring, the solderable shielding ring surrounds the magnetic field gradient sensing module, the signal processing module, and related traces on the circuit board. This electric field shielding structure three-dimensionally shields the spatial electric field generated by the current in the conductor from the magnetic field gradient sensing module, the signal processing module, and related traces on the circuit board, effectively preventing the spatial electric field from interfering with measurements or damaging devices.

[0013] In one embodiment, the front side of the circuit board is provided with a first solderable shielding ring that surrounds the magnetic field gradient sensing module, the signal processing module, and related traces on the circuit board. The front side of the electric field shielding plate is provided with a second solderable shielding ring of the same shape as the first solderable shielding ring. A blind groove is provided on the front side of the electric field shielding plate, inside the second solderable shielding ring. The front side of the circuit board is attached to the front side of the electric field shielding plate, so that the first and second solderable shielding rings overlap.

[0014] The current sensor provided by this invention, without a magnetic core, achieves its various components in a nested, stacked manner through the design of related parts. This allows the current sensor to possess advantages such as small size, simple assembly, wide measurement range, high frequency response, high precision, and strong anti-interference capability. Furthermore, by setting the magnetic sensing unit as an integrated ASIC magnetic sensing chip with pre-adjustable electrical characteristics, the output signal amplitude can be adjusted, effectively meeting the specific requirements of future precise current measurement scenarios for miniaturization, high frequency response, and wide measurement range. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 A schematic diagram of a current sensor provided in this application in one embodiment.

[0017] Figure 2 for Figure 1 A schematic diagram of a structure of the second guide section 120.

[0018] Figure 3 for Figure 1 Another structural schematic diagram of the second fluid guiding section 120.

[0019] Figure 4 This is a schematic diagram showing the relative positions of the magnetic field gradient sensing module and the signal processing module on the circuit board in one embodiment of the present application.

[0020] Figure 5 This is a schematic diagram of the magnetic field gradient detection module in one embodiment of this application.

[0021] Figure 6 This is a schematic diagram of the electric field shielding structure in one embodiment of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] like Figure 1In one embodiment shown, the current sensor provided by the present application includes a current conductor 100 for conducting the current to be measured, a circuit board 200 located inside the current conductor 100, a magnetic field gradient detection module 300 attached to the surface of the circuit board 200, a signal processing module 400 attached to the surface of the circuit board 200, an electrical interface 500, an electric field shielding structure 700 between the current conductor 100 and the circuit board 200, an inverted cylindrical magnetic shielding body 800 covering the outside and the top of the current conductor 100, and a plastic shell structure 600 wrapped around the outside of the current conductor 100 and filling the space between the current conductor 100, the magnetic field gradient detection module 300, the signal processing module 400, the electrical interface 500, the circuit board 200, the electric field shielding structure 700, and the magnetic shielding body 800.

[0025] The inverted cylindrical magnetic shielding body 800 is formed by winding and / or stacking one or more layers of magnetic materials. The material can be permalloy, silicon steel, pure iron, or other ferromagnetic metal materials or alloys, which can effectively weaken or even avoid external magnetic field interference, thereby improving the accuracy and reliability of the current sensor of the present invention. Taking the direction from the barrel mouth to the barrel bottom of the magnetic shielding body 800 as the Y-axis direction, the current conductor 100 is placed inside the magnetic shielding body 800, and it is symmetric about a certain plane parallel to the YZ plane and is in a "Ji" shape or an inverted "U" shape in the YX plane, and the opening direction of the "Ji" shape or the inverted "U" shape is anti-parallel to the Y-axis direction.

[0026] The current conductor 100 includes a first conductor segment 110, a second conductor segment 120, and a third conductor segment 130. The first conductor segment 110 and the second conductor segment 130 are uniform conductor segments. When the current to be measured 900 is passed through the current conductor 100, the magnetic field in the semi-enclosed area where the circuit board 200 is placed, i.e., the inner side of its "Ji" shape or inverted "U" shape, can be significantly enhanced, which is beneficial to improving the signal-to-noise ratio of the detected signal. Further, the first conductor segment 110 is provided with a first diversion slot group 111, the second conductor segment 120 is provided with a second diversion slot group 121, and the third conductor segment 130 is provided with a third diversion slot group 131. The preset number of slots in the first diversion slot group 111 is M, the preset number of slots in the second diversion slot group 121 is N, and the preset number of slots in the third diversion slot group 131 is P, where M, N, and P are natural numbers, and M + N + P ≥ 1. Figure 1 In an embodiment where M = N = P = 1 is illustrated, the purpose of setting the above diversion slots is to further enhance the magnetic field strength in the area below the second diversion slot group 121 and between the first diversion slot group 111 and the third diversion slot group 131. Thus, the magnetic field gradient sensed by the magnetic field gradient detection module 300 in the direction parallel to the Z-axis or anti-parallel to the Z-axis is increased.

[0027] As Figure 1As shown, the magnetic field gradient detection module 300 includes a first magnetic field sensing unit 310 and a second magnetic field sensing unit 320. The sensing center of the first magnetic field sensing unit 310 is located on the center surface of the slots of the first guide slot group 111 and the third guide slot group 131, and is located directly below the second guide slot group 121 along the Y-axis direction. The center surface is perpendicular to the current direction in the guide segment where the corresponding slot is located. The Y-axis coordinates of the sensing centers of the second magnetic field sensing unit 320 and the first magnetic field sensing unit 310 are different. The device layout of the circuit board 200 is as follows. Figure 4 As shown, the second magnetic field sensing unit 320, the first magnetic field sensing unit 310, and the signal conditioning unit 400 are arranged in a straight line along the Y-axis on the circuit board 200, and the signal pin 500 is led out from one side of the circuit board 200 parallel to the Z-axis.

[0028] In practice, the two magnetic field sensing units 310 and 320 can also be configured as follows: the projection of the sensing center of the first magnetic field sensing unit 310 onto the guide section of one of the slot groups falls within the range of that slot group; the projection of the sensing center of the second magnetic field sensing unit onto the guide section of one of the slot groups falls outside the range of that slot group. It is evident that the placement of the magnetic field sensing units is relatively flexible for those skilled in the art, as long as a satisfactory difference exists between the magnetic fields sensed by each of the two magnetic field sensing units.

[0029] like Figure 2 As shown, the second conductor segment 120 of the guide fluid 100 is provided with a second guide slot group 121 along the width D direction (i.e., the Z-axis direction), and the second guide slot group 121 includes a single slot. Combined with... Figure 1 To enhance the magnetic field strength of the inner "U"-shaped guide tube 100, the width W of the second guide tube slot group 121 can be increased. Figure 2 In the embodiment shown, the first magnetic field sensing unit 310 and the second magnetic field sensing unit 320 can be disposed directly below the conductor in the width direction (DW) of the second conductor segment 120 (along the Y-axis direction).

[0030] In addition, you can refer to Figure 3 Another method of configuring the guide slots involves increasing the number of slots in the second guide slot group 121 to two, 121a and 121b, and simultaneously increasing the slot widths W1 and W2 of slots 121a and 121b. This further enhances the magnetic field strength on the side directly below (along the Y-axis) of the guide section 120, thereby further improving the signal-to-noise ratio of the current detection magnetic field. Figure 3 In the embodiment shown, the sensing centers of the first magnetic field sensing unit 310 and the second magnetic field sensing unit 320 can be located directly below the second guide channel group 121 (along the Y-axis direction).

[0031] The slot setting method of the first conductor segment 110 setting the first flow guiding slot group 111 and the third conductor segment 130 setting the third flow guiding slot group 131 is similar to that of the second conductor segment 120 setting the second flow guiding slot group 121. It can be easily obtained by referring to the slot setting method and requirements of the second conductor segment setting the second flow guiding slot group 121, and will not be elaborated here.

[0032] It is worth mentioning that the cross-sectional size of the current guide 100 can be increased to extend the range of the current sensor, and the aspect ratio of the current guide 100 can be adjusted to optimize the high-frequency characteristics of the current sensor.

[0033] Combination Figure 1 and 4 The second magnetic field sensing unit 320 is positioned directly below the first magnetic field sensing unit 310. Clearly, the magnetic field strength at the sensitive center of the first magnetic field sensing unit 310 is significantly stronger than that at the sensitive center of the second magnetic field sensing unit 320, thus enabling magnetic field gradient detection. It should be noted that the second magnetic field sensing unit 320 can also be positioned above the first magnetic field sensing unit 310, or at any other location on a plane not parallel to the XZ plane.

[0034] Furthermore, the first magnetic field sensing unit 310 and the second magnetic field sensing unit 320 can each be composed of several magnetic sensing units connected in series or in parallel, and all magnetic sensing units are identical. Figure 5 The diagram illustrates another configuration of the first and second magnetic field sensing units. The first magnetic field sensing unit 310 includes magnetic sensing units 310a, 310b, and 310c, with their sensing centers located within a plane 903 perpendicular to the Y-axis. The second magnetic field sensing unit 320 is composed of magnetic sensing units 320a, 320b, and 320c, with their sensing centers located within a plane 904 perpendicular to the Y-axis. Planes 903 and 904 do not coincide. Compared to Figure 4 The layout of the magnetic field sensing unit shown is as follows: Figure 5 The magnetic field sensing unit shown contains more magnetic sensing units, which can disperse and reduce the adverse effects caused by the misalignment of the magnetic sensing unit assembly position, thus having a stronger signal fault tolerance and anti-interference characteristics, and therefore a better signal-to-noise ratio, but will also cause a corresponding increase in the overall cost of the current sensor.

[0035] It is worth mentioning that, Figure 5In this embodiment, the sensing centers of magnetic sensing units 310a, 310b, and 310c may not be in the same plane perpendicular to the Y-axis. Similarly, magnetic sensing units 320a, 320b, and 320c may also not be in the same plane perpendicular to the Y-axis. The requirement is that the difference between the magnetic fields sensed by each of the two magnetic field sensing units meets the measurement requirements.

[0036] To reduce measurement errors, the aforementioned magnetic sensing unit can be an integrated ASIC magnetic sensing chip with pre-adjustable electrical characteristics, or a magnetic sensing element with highly similar electrical characteristics. When using an integrated ASIC magnetic sensing chip, the zero point, sensitivity, temperature drift, and frequency response characteristics of the magnetic sensing chip can be pre-adjusted to be highly similar, thereby eliminating the adverse effects introduced by individual device differences and improving the accuracy of current detection. The current sensor embodiment provided by this invention allows for flexible adjustment of the balance between sensor signal-to-noise ratio and cost by adjusting the number of magnetic sensing units, adapting to different application scenarios.

[0037] The signal processing module 400 receives the gradient detection signal (i.e., the output signals of the first magnetic field detection group 310 and the second magnetic field detection group 320, or the difference between their output signals) transmitted by the magnetic field gradient detection module 300, converts it into a corresponding current value, and outputs it through the electrical interface 500. To improve the measurement accuracy of the current sensor, enrich the output signal formats of the current sensor, and enhance the applicability of the current sensor, the signal processing module 400 may also include one or a combination of a zero-point adjustment unit, a gain adjustment unit, a temperature compensation unit, a nonlinear compensation unit, an analog-to-digital conversion processing unit, and a communication interface unit.

[0038] To avoid electric field interference during the measurement of alternating large currents by the current sensor provided in this application, which could lead to inaccurate measurements or damage to the device, therefore, in Figure 1 In this embodiment, the current sensor further includes an electric field shielding structure 700 disposed between the circuit board 200 and the fluid conductor 100, and the electric field shielding structure 700 is electrically connected to the circuit board 200. The electric field shielding structure 700 is based on a non-magnetic metal material that encapsulates the magnetic field gradient module 300, the signal processing module 400, and related circuits on the circuit board, thereby shielding the spatial electric field generated when a current 900 is passed through the fluid conductor 100 (especially for current measurement in high-voltage systems). By setting the electric field shielding structure 700, the adverse effects of the spatial electric field generated by the current in the fluid conductor on signal detection and processing can be effectively avoided, preventing the spatial electric field from causing measurement deviations and accidental damage to the current sensor, and improving the reliability and applicability of the current sensor.

[0039] exist Figure 6In the described embodiment, the field shielding structure 700 includes an electric field shielding plate 70 (which may be a rigid PCB board). An "n"-shaped solderable shielding ring 701 is arranged on the top surface (i.e., the front side) of the electric field shielding plate 700, and a blind slot 702 is provided from top to bottom. Its bottom layer is a copper-clad layer 703. Correspondingly, a magnetic field detection module 300, a signal processing module 400, and an electrical interface 500 are arranged on the top surface (i.e., the front side) of the circuit board 200. A solderable shielding ring 201 of the same size and shape as the shielding ring 701 is provided on the outer side. The bottom layer of the circuit board 200 is a copper-clad layer 202. After the electric field shielding plate 70 and the circuit board 200 are folded along a straight line 905, the solderable shielding rings 701 and 201 completely overlap. After soldering, together with the bottom copper-clad layer 703 of the electric field shielding plate 70 and the bottom copper-clad layer 202 of the circuit board 200, they construct a three-dimensional electric field shielding region that approximates a Faraday cage. This three-dimensional electric field shielding area surrounds the first magnetic field detection group 310, the second magnetic field detection group 320, the signal processing module 400, and the related signal traces on the circuit board 200, protecting them from external mechanical impacts and electric field interference. Clearly, the shape and size of the solderable shielding ring 701 and the blind slot 702 can be adjusted according to the layout of the first magnetic field detection group 310, the second magnetic field detection group 320, the signal processing module 400, and the electrical interface 500 on the top surface of the circuit board 200.

[0040] Obviously, in Figure 6 In the described embodiment, the solderable shielding ring with a notch for leading signal lines can be provided only on the front side of the circuit board 200 or the top surface of the electric field shielding plate 70. During soldering, the solderable shielding ring is simply made to wrap around the magnetic field gradient sensing module 300, the signal processing module 400, and the signal traces on the circuit board 200.

[0041] The current sensor provided in this application, by abandoning the magnetic core, achieves the assembly of various parts of the current sensor in a nested manner through structural optimization of related components. Simultaneously, the current is measured by magnetic field gradient detection through the structural design of the fluid guide. Based on the above design optimization, the current sensor provided in this application possesses advantages such as small size, simple assembly, wide measurement range, high frequency response, high precision, and strong anti-interference capability.

[0042] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A coreless current sensor characterized by, The current sensor comprises a magnetic shielding body in an inverted cylinder shape, a flow guide, a magnetic field gradient sensing module and a signal processing module; The flow guide is built inside the magnetic shielding body, with the direction from the cylinder top to the cylinder bottom of the magnetic shielding body as the Y-axis direction, the projection of the flow guide on the YX plane as a "V" shape or an inverted "U" shape, and the opening direction of the "V" shape or the inverted "U" shape being anti-parallel to the Y-axis direction; At least one slot group is present on at least one of the first flow guide section, the second flow guide section and the third flow guide section of the flow guide, and the at least one slot group is used to enhance / construct the magnetic field gradient signal sensed by the gradient sensing module; the first flow guide section and the third flow guide section are parallel and not collinear, and one end of the second flow guide section is connected to the first flow guide section and the other end is connected to the third flow guide section; The signal processing module calculates the size of the current flowing through the flow guide based on the output signal of the magnetic field gradient sensing module.

2. The current sensor of claim 1, wherein, The projection of the gradient sensing module on the YX plane is located inside the "V" shape or the inverted "U" shape projection of the flow guide.

3. The current sensor of any one of claims 1-2, wherein, The current sensor further comprises an electric field shielding structure whose projection on the YX plane is located inside the "V" shape or the inverted "U" shape projection of the flow guide on the YX plane; the magnetic field gradient sensing module and the signal processing module are arranged on the same circuit board, the electric field shielding structure is made of a non-magnetic metal material and is used to wrap the magnetic field gradient sensing module, the signal processing module and the relevant wiring on the circuit board, and a notch is arranged to lead out the signal lead.

4. The current sensor of claim 3, wherein, The gradient sensing module comprises two identical magnetic field sensing units, and the output signal is generated based on the sensing signals of the two magnetic field sensing units; the sensing direction of the two magnetic field sensing units is the Z-axis direction or anti-parallel to the Z-axis direction.

5. The current sensor of claim 4, wherein, The projection of the sensing center of the first magnetic field sensing unit on the flow guide section to which the slot group belongs falls within the range of the slot group, and the projection of the sensing center of the second magnetic field sensing unit on the flow guide section to which the slot group belongs falls outside the range of the slot group.

6. The current sensor of claim 5, wherein, The sensing center of the first magnetic field sensing unit is located on the center plane of at least one slot of the slot group, and the center plane is perpendicular to the current direction in the flow guide section where the at least one slot is located.

7. The current sensor of any one of claims 4-6, wherein, The sensing centers of the two magnetic field sensing units are arranged along the Y-axis direction.

8. The current sensor of any one of claims 4-6, wherein, The first magnetic field sensing unit and the second magnetic field sensing unit are respectively composed of a plurality of magnetic sensitive units in series or in parallel.

9. The current sensor of claim 8, wherein, The magnetic sensitive units of the first magnetic field sensing unit are all located on a first plane parallel to the XZ plane, the magnetic sensitive units of the second magnetic field sensing unit are all located on a second plane parallel to the XZ plane, and all the magnetic sensitive units are identical; the first plane does not coincide with the second plane.

10. The current sensor of claim 3, wherein, The electric field shielding structure comprises a copper layer on the back surface of the circuit board and an electric field shielding plate; the front surface of the circuit board is provided with the magnetic field gradient sensing module and the signal processing module; at least one of the front surface of the circuit board or the front surface of the electric field shielding plate is provided with a solderable shielding ring, which is provided with an outgoing notch of a signal lead; after the front surface of the circuit board and the front surface of the electric field shielding plate are attached and soldered through the solderable shielding ring, the solderable shielding ring surrounds the magnetic field gradient sensing module, the signal processing module and the related wiring on the circuit board.

11. The current sensor of claim 10, wherein, The front surface of the circuit board is provided with the first solderable shielding ring surrounding the magnetic field gradient sensing module, the signal processing module and the related wiring on the circuit board; the front surface of the electric field shielding plate is provided with the second solderable shielding ring which has the same shape as the first solderable shielding ring; the part of the front surface of the electric field shielding plate inside the second solderable shielding ring is provided with a blind groove; the front surface of the circuit board is attached to the front surface of the electric field shielding plate, so that the first and second solderable shielding rings overlap.

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