A current sensor

Abstract

The application provides a current sensor. The current sensor adopts a non-magnetic core design, and a specially-structured current guide array is used to guide target current to enhance the energizing capacity of the current sensor and reduce the adverse effect of high-frequency current skin effect on measurement. Based on the structural characteristics of the current guide array, a magnetic sensitive component for measuring target current is arranged, and a corresponding sensing signal processing method is used to improve the measurement accuracy of high-frequency large current, improve the interference magnetic field suppression capability, and improve the signal-to-noise ratio of the effective measurement signal. The current sensor provided by the application has the advantages of compact structure, simple manufacturing process, strong energizing capacity, high signal-to-noise ratio of sensing signal, and the like. The current sensor not only widens the range of the current sensor, but also effectively improves the measurement accuracy of high-frequency large current, and expands the application range of the non-magnetic core type current sensor.

Description

Technical Field

[0001] This application relates to the field of current measurement technology or equipment, and in particular to a current sensor that is accurate, compact, and coreless for high-frequency, high-current measurement. Background Technology

[0002] Currently, the following selection rules apply to sensors commonly used for measuring currents up to 1000A: For target currents below 50A, chip-level current sensors can be used; for target currents below 150A, on-board open-loop current sensors are the mainstream choice; and for target currents above 150A, through-hole open-loop or closed-loop current sensors are generally used. This selection is based on the fact that chip-level current sensors are limited by the current-carrying capacity and heat dissipation issues of the primary conductor, making them incompatible with larger current measurement ranges. On-board open-loop current sensors, through-hole open-loop or closed-loop current sensors, due to their built-in magnetic cores, have higher heat dissipation performance and can guide larger currents; however, the magnetic core often needs to be encased outside the primary conductor, resulting in a relatively large sensor size.

[0003] Furthermore, existing onboard open-loop current sensors, through-hole open-loop or closed-loop current sensors often increase their current-carrying capacity by increasing the thickness of the current-carrying busbar in order to minimize their size. However, increasing the thickness of the current-carrying busbar will significantly reduce the measurement accuracy when measuring high-frequency current, or even make it impossible to measure effectively. This is due to the skin effect and the influence of parasitic capacitance and inductance when high-frequency current passes through the current-carrying busbar. Summary of the Invention

[0004] In view of this, this application utilizes a specially designed stacked current guide with corresponding magnetic sensitive components and employs differential signal processing to realize a coreless current sensor suitable for high-frequency, high-current measurement, featuring good anti-interference capability, compact structure, high signal-to-noise ratio, and wide measurement range.

[0005] The current sensor provided in this application includes: a current bus group, a first magnetic sensing component, a second magnetic sensing component, and a signal conditioning unit.

[0006] The current-carrying busbar assembly has two parallel current-carrying busbars of the same shape. Each current-carrying busbar is a flat metal conductor with two parallel, symmetrical, and non-coaxial current-carrying segments. The axes of symmetry between the two current-carrying segments of each of the two current-carrying busbars coincide. Each current-carrying segment of one current-carrying busbar is stacked on top of a current-carrying segment of the other current-carrying busbar, and the current flows in opposite directions in the two stacked current-carrying segments.

[0007] The first and second magnetic sensing components are stacked on top of each of the two guide sections of any flow guide, with their sensing directions being the same or opposite, both parallel to the width direction of the corresponding guide section. The first and second magnetic sensing components are simultaneously stacked above or below one of the planes of the two guide sections of any flow guide, and their sensing centers are symmetrical about the axis of symmetry of the two guide sections of any flow guide.

[0008] The signal conditioning unit processes the sensing signal of the first magnetic sensor through differential processing. The sensing signal of the second magnetic sensing component Obtain the target signal characterizing the target current flowing through the current guide assembly. .

[0009] The current sensor described above employs two parallel, stacked current-carrying busbars to enhance the high-frequency current carrying capacity, reduce interference from the skin effect, parasitic capacitance, and parasitic inductance, and improve the current carrying capacity and current measurement range. Correspondingly, the magnetic sensing element is positioned on opposite, stacked current-carrying sections, and differential processing is used to obtain the target signal indicating the magnitude of the current flowing through the current-carrying busbars. This not only further reduces the influence of interference fields but also improves the signal-to-noise ratio of the target signal.

[0010] Furthermore, both the first and second magnetic sensitive components are located between two overlapping flow guide sections. Alternatively, both the first and second magnetic sensitive components are located above or below one side of the two overlapping flow guide sections.

[0011] Preferably, each of the flow guide sections has a slot, and the first magnetic sensitive component and the second magnetic sensitive component are directly opposite the slots of the flow guide sections stacked together.

[0012] In some embodiments, the first magnetic sensing component and the second magnetic sensing component each include one magnetic sensing unit; the sensitive center of any magnetic sensing unit is located directly above or below the centerline of the width of the flow guide section stacked with it. The magnetic sensing unit is a Hall element or an ASIC unit integrating a Hall element, an XMR magnetoresistive element or an ASIC unit integrating an XMR magnetoresistive element, wherein the XMR includes at least TMR, AMR, and GMR.

[0013] In another embodiment, the first magnetic sensitive component and the second magnetic sensitive component are respectively composed of N magnetic sensitive units connected in series, in parallel, or in series and parallel; Preferably, the magnetic sensing units of any magnetic sensing component are arranged along the width direction, and the sensitive center spacing D of the two outermost magnetic sensing units and the width W of the row opposite the guide section satisfy the following relationship: 0.2W≤D≤0.8W.

[0014] The current sensor provided by this invention utilizes a specially designed stacked current-conducting busbar and a corresponding magnetic sensing component layout, employing differential signal processing to adapt to the measurement of high-frequency, high-current signals. This current sensor, without using a magnetic core (ensuring controllable sensor size), offers advantages such as excellent anti-interference capability and a wide measurement range. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in 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 the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 A top view of one embodiment of the current sensor provided by the present invention.

[0017] Figure 2 for Figure 1 The diagram shows the disassembled current busbar of the current sensor.

[0018] Figure 3 for Figure 1 The image shows a front cross-sectional view of the current sensor.

[0019] Figure 4 This is a schematic diagram of a signal conditioning unit in one embodiment of the current sensor provided by the present invention.

[0020] Figure 5 A schematic diagram of the magnetic sensing component in another embodiment of the current sensor provided by the present invention.

[0021] Figure 6 This is a schematic diagram of the current busbar assembly in another embodiment of the current sensor provided by the present invention.

[0022] Figure 7 A front sectional view of another embodiment of the current sensor provided by the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In this application, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0026] The technical solution provided by the present invention will be further described in detail below with reference to the accompanying drawings.

[0027] In one embodiment, the top perspective view of the current sensor provided by the present invention is as follows: Figure 1 As shown. The current sensor includes: a current-carrying busbar 100, a magnetic sensing component 200, a signal conditioning unit 300, a circuit board 400, an electrical interface 500, and a plastic housing 600.

[0028] The current guide assembly 100 consists of two parallel, identically shaped first current guides 110 and second current guides 120; the first current guides 110 are stacked directly above the second current guides 120. Each current guide is a flat metal conductor with two parallel, symmetrical, and non-coaxial current guide segments. Figure 1 In the diagram, the first current-conducting bus 110 and the second current-conducting bus 120 are flat metal conductors that are symmetrical about the axis of symmetry 800 and have a stable shape. The axis of symmetry 800 of the first current-conducting bus 110 and the second current-conducting bus coincide, and the current flows in opposite directions in the two overlapping current-conducting sections directly opposite to the magnetic sensitive component 200 (i.e., ...). Figure 1 The directions of currents 801 and 802 are opposite at the location directly opposite the magnetic sensitive component 200.

[0029] The magnetic sensing component 200 includes a first magnetic sensing component 210 and a second magnetic sensing component 220. The first magnetic sensing component 210 and the second magnetic sensing component 220 are respectively stacked with two guide sections of each guide bar, and both have the same sensing direction, which is parallel to the width direction of the corresponding guide section.

[0030] That is, the first magnetic sensitive component 210 and the second magnetic sensitive component 220 can both be located between two overlapping flow guide sections, or both can be located above or below one side of the two overlapping flow guide sections. Preferably, the first magnetic sensitive component 210 and the second magnetic sensitive component 220 have the same performance parameters.

[0031] exist Figure 1In the illustrated embodiment, the first magnetic sensitive component 210 and the second magnetic sensitive component 220 are disposed in the region between the first guide bar 110 and the second guide bar 120, and the sensitive center is symmetrical about the axis of symmetry 800. The first magnetic sensitive component 210, the second magnetic sensitive component 220, and the signal conditioning unit 300 are attached to the surface of the circuit board 400 and electrically connected to the electrical interface 500, and are encased in a plastic shell 600 to achieve structural stability and electrical insulation.

[0032] The signal conditioning unit processes the sensing signal of the first magnetic sensor 210 through differential processing. The sensing signal of the second magnetic sensing component 220 Obtain the target signal characterizing the target current flowing through the current guide assembly. .

[0033] For ease of explanation and visual illustration, Figure 2 The first guide vane 110 and the second guide vane 120 are respectively translated equidistantly to the left and right along the axis of symmetry 800. Combined Figure 1 and Figure 2 To illustrate, the target current to be measured is diverted through the current guide assembly 100. Divided into and The two parts are 801 and 802 in the diagram. If the first guide vane 110 and the second guide vane 120 are identical, then... The current component The current flows in at the beginning 111 of the first guide bar 110, and flows out at the end 112 of the first guide bar 110 after passing through the first guide section 113 and the second guide section 114. Current component The current flows in at the first end 121 of the second guide column 120, and flows out at the last end 122 of the second guide column 120 after passing through the third guide section 123 and the fourth guide section 124. Current component and The flow direction in the first guide column 110 and the second guide column 120 is as follows: Figure 2 As shown.

[0034] It should be noted that the first current guide 110 and the second current guide 120 are placed in opposite parallel directions. The first current guide segment 113 of the first current guide 110 is located directly above the third current guide segment 123 of the second current guide 120, and the second current guide segment 114 of the first current guide 110 is located directly above the fourth current guide segment 124 of the second current guide 120. Obviously, the current directions in the first current guide segment 113 and the third current guide segment 123 are opposite, and the current directions in the second current guide segment 114 and the fourth current guide segment 124 are opposite.

[0035] Figure 3 for Figure 1The image shows a front cross-sectional view of the current sensor described. The first magnetic sensing component 210 is positioned directly below the first guide section 113 of the first guide fluid 110 and directly above the third guide section 123 of the second guide fluid 120. The second magnetic sensing component 220 is positioned directly below the second guide section 114 of the first guide fluid 110 and directly above the fourth guide section 124 of the second guide fluid 120. The first magnetic sensing component 210 and the second magnetic sensing component 220 have the same (corresponding to differential processing) or opposite-parallel (corresponding to summation) sensing directions, and are parallel or opposite-parallel to the target current. The magnetic field generated at its sensitive center. Current component. The flow directions in the first guide section 113 and the second guide section 114 are 803 and 804, respectively, and magnetic fields 807 and 808 are generated around the first guide section 113 and the second guide section 114, respectively. Current component The flow directions in the third guide section 123 and the fourth guide section 124 are 805 and 806, respectively, and magnetic fields 809 and 810 are generated around the third guide section 123 and the fourth guide section 124, respectively. Magnetic field 803 is opposite to magnetic fields 804 / 805, magnetic field 804 is opposite to magnetic field 806, and magnetic fields 807 and 808, and magnetic fields 809 and 810 are symmetrically distributed in opposite directions. Magnetic fields 807 and 809 generate a superimposed magnetic field at the sensitive center of the first magnetic sensitive component 210. The direction is 811; magnetic fields 808 and 810 generate a superimposed magnetic field at the sensitive center of the second magnetic sensitive component 220. The direction is 812; superimposed magnetic field and They are equal in size but opposite in direction.

[0036] The first magnetic sensing element 210 detects the superimposed magnetic field. Linear output signal The second magnetic sensing component 220 detects the superimposed magnetic field. Linear output signal ,exist:

[0037] ;

[0038] ;

[0039] in, and These are the sensitivities of the first magnetic sensitive component 210 and the second magnetic sensitive component 220, respectively. and These are the zero-point drifts of the first magnetic sensitive component 210 and the second magnetic sensitive component 220, respectively.

[0040] The signal conditioning unit 300 receives the output signals from the first magnetic sensing component 210 and the second magnetic sensing component 220. and After conditioning, the output signal can characterize the magnitude, phase, frequency, and other properties of the target current. By analyzing the target signal Demodulation allows for accurate measurement of the target current. It can be inferred that:

[0041] ;

[0042] in, Not zero, is the non-zero amplification factor of the signal conditioning unit.

[0043] Figure 4 This is a schematic diagram of the signal conditioning unit 300 of the current sensor provided by the present invention in one embodiment. The signal output by the first magnetic sensing component 210 of the magnetic sensing component 200... and the signal output by the second magnetic sensitive component 220 The signals are connected to the differential processing unit of the signal conditioning unit 300, and then sequentially pass through the zero-adjustment unit, gain adjustment unit, temperature compensation unit, and nonlinear compensation unit to finally obtain the target signal. Combining the above formula, the zero-adjustment unit is responsible for adjusting the signal components. The gain adjustment unit adjusts the gain according to the preset target signal. With target current Transformation relationship, adjust the equivalent amplification factor of the signal conditioning unit. This is to meet the gain requirements of the current sensor. The temperature compensation unit is used to eliminate the adverse effects of temperature changes on the validity of the above formula, thereby ensuring the low temperature drift characteristics of the current sensor within its operating temperature range. If necessary, the target signal can be adjusted using a nonlinear compensation unit. With superimposed magnetic field or equivalent to the target signal With target current The nonlinearity is ensured to guarantee the monotonic linear variation characteristics of the current sensor.

[0044] The first magnetic sensing component 210 and the second magnetic sensing component 220 are each composed of N magnetic sensing units connected in series, in parallel, or in a series-parallel configuration, where N is a positive integer. The sensing centers of the sensing units of the first magnetic sensing component 210 and the second magnetic sensing component 220 are symmetrical about the axis of symmetry 800 of the current-carrying array. The magnetic sensing units are Hall elements or ASIC units integrating Hall elements, or XMR magnetoresistive ASIC units integrating XMR magnetoresistive elements. The XMR includes at least TMR, AMR, and GMR.

[0045] Preferably, the magnetic sensing unit is an integrated ASIC magnetic sensing unit. This allows for the programming of corresponding data to ensure that the electrical characteristics of each magnetic sensing unit are highly similar, particularly in terms of zero-point, sensitivity, temperature drift, and frequency response characteristics. This improves the measurement accuracy of the current sensor and appropriately reduces over-reliance on the signal conditioning unit 300. To save costs, in practical applications, magnetic sensing elements of the same type with highly similar zero-point, sensitivity, temperature drift, and frequency response characteristics can be selected as the constituent units of the first magnetic sensing component 210 and the second magnetic sensing component 220, which can also meet the needs of most application scenarios with less stringent requirements.

[0046] Preferably, when N=1, the sensitive center of the first magnetic sensitive component 210 is located directly below the center line of the first guide section or directly above the center line of the third guide section, and the sensitive center of the second magnetic sensitive component 220 is preferably located directly below the center line of the second guide section or directly above the center line of the fourth guide section.

[0047] When N > 1, the sensitive center spacing D of the two outermost magnetic sensitive units of the first magnetic sensitive component 210 and the second magnetic sensitive component 220 has the following relationship with the width W of the first guide section, the second guide section, the third guide section, or the fourth guide section: . Reference Figure 5 (N=3), the first magnetic sensitive component 210 includes three magnetic sensitive units 211, 212, and 213, and the second magnetic sensitive component 220 includes magnetic sensitive units 221, 222, and 223. The sensitive center spacing D between the two magnetic sensitive units 211 and 213 on the outer side of the first magnetic sensitive component 210 or the two magnetic sensitive units 221 and 223 on the outer side of the second magnetic sensitive component 220 is related to the width W of the third guide section 123 or the fourth guide section 124: This setup helps eliminate measurement errors caused by uneven flow of the target current in the current-carrying array.

[0048] like Figure 6 In another embodiment, in order to increase the superimposed magnetic field... and To improve the signal-to-noise ratio of the current sensor, or to reduce the signal conditioning amplification factor. To optimize and improve the high-frequency characteristics of the current sensor, guide slots 125, 126, 127, and 128 can be provided on one or both sides of the third guide section 123 and the fourth guide section 124 of the second guide bar 120. Undoubtedly, the first guide bar can also be adjusted accordingly, and will not be elaborated upon here.

[0049] Furthermore, in addition to being located between the two stacked flow guide sections, the first magnetic sensitive component 210 and the second magnetic sensitive component 220 can also be located on one side above or below the two stacked flow guide sections. For example... Figure 7 As shown, the first magnetic sensitive component 210 and the second magnetic sensitive component 220 can also be symmetrically distributed on the upper or lower sides of the first flow guide 110 and the second flow guide 120. That is, the first magnetic sensitive component 210 and the second magnetic sensitive component 220 are both disposed on one side of the flow guide assembly 100.

[0050] in, Figure 7 In the illustrated embodiment, the current guide assembly consists of two stacked current guides 110 and 120, connected in parallel. Target current. Divided into and Two parts, current component The current component flows in from the first guide section 113 of the guide tube 110 and flows out through the second guide section 114. The current flows in through the fourth guide section 124 of the current guide 120 and out through the third guide section 123. The purpose of this arrangement is to adjust the current guide group into a composite stacked parallel form of multiple current guides of the same shape while maintaining the current carrying capacity. This optimizes the aspect ratio of a single current guide to improve the high-frequency characteristics of the current sensor in the embodiment, and reduces the magnetic field at the location of the magnetic sensitive component, preventing premature saturation and increasing the magnitude of the effective measurement current.

[0051] The current sensor provided by this invention has the advantages of being coreless, small in size, compact in structure, and simple in process. Furthermore, the flatness ratio, vertical stacking method, and current conduction mode of multiple current guides can be adjusted to broaden the measurement range of the current sensor (the current guide group can carry a larger current), improve the signal-to-noise ratio and measurement accuracy, and optimize high-frequency characteristics. The current sensor designed based on a single principle can cover more application scenarios and has extremely high practical value.

[0052] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A current sensor, characterized in that, The current sensor includes: a current-carrying busbar assembly, a first magnetic sensing component, a second magnetic sensing component, and a signal conditioning unit; The current-conducting busbar assembly has two identical current-conducting busbars connected in parallel. Each current-conducting busbar is a flat metal conductor with two parallel, symmetrical, and non-linear current-conducting segments. The axes of symmetry between the two current-conducting segments of each of the two current-conducting busbars in the assembly coincide. Each current-conducting segment of one current-conducting busbar is stacked on top of the current-conducting segment of the other current-conducting busbar, and the current flows in opposite directions in the two stacked current-conducting segments. The first magnetic sensing component and the second magnetic sensing component are respectively stacked on the two guide sections of any flow guide. The sensing directions of the two components are the same or opposite and are parallel to the width direction of the corresponding flow guide section. The first magnetic sensing component and the second magnetic sensing component are simultaneously stacked on one of the planes above or below the two flow guide sections of any flow guide, and the sensing center is symmetrical about the axis of symmetry of the two flow guide sections of any flow guide. The signal conditioning unit differentially processes the sensing signal of the first magnetic sensor. The sensing signal of the second magnetic sensing component To obtain a target signal characterizing the target current flowing through the current guide assembly. .

2. The current sensor as described in claim 1, characterized in that, The first magnetic sensitive component and the second magnetic sensitive component are both located between two overlapping flow guide sections.

3. The current sensor as described in claim 1, characterized in that, The first magnetic sensitive component and the second magnetic sensitive component are both located above or below one of the two mutually stacked flow guide sections.

4. The current sensor as described in any one of claims 1-3, characterized in that, Each of the flow guide sections has a slot; the first magnetic sensitive component and the second magnetic sensitive component are directly opposite the slots of their stacked flow guide sections.

5. The current sensor as described in claim 4, characterized in that, The first magnetic sensing component and the second magnetic sensing component each include one magnetic sensing unit; the sensitive center of any magnetic sensing unit is located directly above or directly below the center line of the width of the flow guide section stacked with it.

6. The current sensor as described in claim 4, characterized in that, The first magnetic sensing component and the second magnetic sensing component are each composed of N magnetic sensing units connected in series, in parallel, or in series and in parallel. .

7. The current sensor as described in claim 6, characterized in that, The magnetic sensing units of any magnetic sensing component are arranged along the width direction, and the sensitive center spacing D of the two outermost magnetic sensing units has the following relationship with the width W of the row opposite the guide section: 0.2W≤D≤0.8W.

8. The current sensor as described in any one of claims 5-7, characterized in that, The magnetic sensing unit is a Hall element or an ASIC unit integrating a Hall element, an XMR magnetoresistive element or an ASIC unit integrating an XMR magnetoresistive element, and the XMR includes at least TMR, AMR, and GMR.

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