Current Sensor

Abstract

An embodiment of the present invention discloses a current sensor. The current sensor comprises a current conductor to be measured, which comprises a first conductor section and a second conductor section of the same shape. The area enclosed by the extended shapes of the first conductor section and the second conductor section is U-shaped, and the two conductor sections are distributed symmetrically around the geometric centerline of the current conductor to be measured. A first group of magnetic sensors is arranged on one or two sides of the first conductor section. A second group of magnetic sensors is also arranged on one or two sides of the first conductor section. These two groups of magnetic sensors are distributed symmetrically around the geometric centerline of the current conductor to be measured and have the same sensing direction. All sides are surrounded by a shielding cover, which is placed in a housing made of an insulating material that encases the current conductor to be measured, the first group of magnetic sensors, the second group of magnetic sensors, and a signal processor and a circuit board. The current sensor provided by the embodiments of the present invention has small size, strong anti-interference, wide measurement range, little temperature drift, high frequency response, and high measurement accuracy.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to the field of magnetic sensor technology, and in particular to current sensors. [Background technology]

[0002] For many years, there has been a large and important demand for current sensors in industries such as power systems, wind power generation, solar power generation, frequency converters, rail transportation, and industrial control. With the rapid development of artificial intelligence and the Internet of Smart Things, the requirements for current sensors will continue to increase. Miniaturization, integration, high frequency response, and fast response are the future development directions for current sensors.

[0003] Currently, shunts, current transformers, Hall current sensors, and fluxgate current sensors commonly used for current measurement achieve current detection by detecting changes in the electric or magnetic field generated by the conductor being measured in different ways. Patent application CN200410069833.X discloses a method for manufacturing an open-loop current sensor, the operating principle of which is to use a magnetic field detector placed in the air gap of an iron core to detect changes in the magnetic field generated by the conductor being measured, thereby achieving current detection. However, this solution has drawbacks, such as the relatively large size of the iron core, the high cost, and poor high-frequency characteristics, which tend to generate eddy currents in the iron core when high-frequency components are present, creating a safety risk. Patent application CN201210409149.6 discloses a current sensor. This current sensor includes a magnetoresistive integrated chip, an operational amplifier, a resistor, a printed circuit board, and a U-shaped electric wire being measured. The differential magnetic field generated by the U-shaped wire is detected by a full-bridge magnetoresistive integrated chip, thereby achieving current detection. However, the above-mentioned current sensor has drawbacks, such as the need to arrange multiple soft magnetic layers and compensation lead layers, the relatively complex process requirements, and poor anti-interference performance. When a large current passes through the current sensor or there is interference from a certain external magnetic field, one or two bridge arms of the magnetoresistive integrated chip can easily become saturated, which will affect the sensor's measurement accuracy.

[0004] Current transformers, Hall current sensors, and fluxgate current sensors require the use of a magnetic ring structure to amplify the magnetic field and improve measurement accuracy, thereby achieving isolated current measurement. During current measurement, the current conductor to be measured must pass through the central hole of the magnetic ring. Therefore, the volume of the measurement device depends on the size of the current conductor and the magnetic ring. Meanwhile, the frequency characteristics of the magnetic ring itself severely limit the frequency response characteristics of the measurement device, making it difficult for the measurement device to achieve a fast response and a wide measurement bandwidth. These types of sensors, which have a large rated current, are bulky and expensive, preventing their widespread use. Furthermore, the inflexibility of the solution makes it difficult to flexibly adapt to different current measurement scenarios. Summary of the Invention

[0005] SUMMARY OF THE INVENTION Embodiments of the present invention provide a current sensor that solves problems of existing current sensors, such as narrow measurement range, poor high frequency characteristics, low measurement accuracy, and large size.

[0006] One embodiment of the present invention provides a current sensor, the current sensor comprising: a current conductor to be measured, the current conductor including a first conductor section and a second conductor section of identical shape, the area encompassed by the extended shapes of the first conductor section and the second conductor section being "U" shaped, and the first conductor section and the second conductor section being symmetrically distributed around a geometric centerline of the current conductor to be measured; a first group of magnetic sensors and a second group of magnetic sensors, the first group of magnetic sensors being arranged on one or two sides of a first conductor section and the second group of magnetic sensors being arranged on one or two sides of a second conductor section, the first group of magnetic sensors and the second group of magnetic sensors being distributed symmetrically around a geometric centerline of the current conductor to be measured, and the first group of magnetic sensors and the second group of magnetic sensors having the same sensing direction; The device includes a signal processor, a circuit board, and a fully enclosed shielding cover, the shielding cover being placed within the housing and enclosing the current conductor to be measured, the first group of magnetic sensors, the second group of magnetic sensors, the signal processor, and the circuit board.

[0007] After a current flows through the current conductor to be measured, the first conductor section and the second conductor section generate magnetic fields to be measured above and below the geometric centerline, respectively. The magnetic fields to be measured have the same magnitude and are distributed symmetrically in opposite directions around the geometric centerline of the current conductor to be measured. A first group of magnetic sensors is used to detect the first magnetic field to be measured generated by the current flowing through the first conductor section of the current conductor to be measured, and a second group of magnetic sensors is used to detect the second magnetic field to be measured generated by the current flowing through the second conductor section of the current conductor to be measured. The first magnetic field to be measured and the second magnetic field to be measured form a differential magnetic field to be measured. The first magnetic sensor group and the second magnetic sensor group are converted into a differential voltage signal by the signal processor. The differential voltage signal is processed by a signal processor and converted into an output signal that is proportional to the current to be measured and changes in real time in conjunction with the current to be measured. The output signal is output by lead wires connected to a circuit board.

[0008] Furthermore, the current conductor to be measured is a single-material metal conductor or a homogeneous alloy conductor.

[0009] Furthermore, the cross-sectional shape of the symmetrical area of ​​the current conductor to be measured is rectangular, trapezoidal, circular, or semicircular.

[0010] Furthermore, the first group of magnetic sensors and the second group of magnetic sensors are symmetrically arranged on a circuit board, and the circuit board is symmetrically distributed on one or two sides of a current conductor to be measured; each of the first magnetic sensor group and the second magnetic sensor group is composed of M magnetic sensor units arranged in parallel and spaced apart on one or two sides of the first conductor section, the magnetic sensor units being mounted on a circuit board, where M is a positive integer; The output signal of the first magnetic sensor group and the output signal of the second magnetic sensor group are respectively the average values ​​of the converted signals of the M magnetic sensor units, and the output signal of the first magnetic sensor group and the output signal of the second magnetic sensor group construct a differential voltage signal.

[0011] Furthermore, the magnetic sensor unit is a Hall sensor, an anisotropic magnetic sensor, a giant magnetic sensor, or a tunnel magnetic sensor.

[0012] Furthermore, the material of the shielding cover is permalloy, silicon steel, pure iron, a magnetically conductive metal material, or an alloy.

[0013] The signal processor further includes a temperature compensation unit, a nonlinear compensation unit, and an operational amplifier, and the differential voltage signals converted by the first and second magnetic sensor groups are sequentially passed through the temperature compensation unit, the nonlinear compensation unit, and the operational amplifier to form an output signal of the current sensor.

[0014] In an embodiment of the present invention, the current conductor to be measured by the current sensor is U-shaped. The first magnetic sensor group is arranged on one or two sides of the first conductor section, and the second magnetic sensor group is arranged on one or two sides of the second conductor section. This eliminates the need for a magnetic flux collection structure, resulting in a small overall structure and low cost, while significantly improving the frequency response characteristics of the current sensor. The current sensor uses the first magnetic sensor group to detect the magnetic field to be measured in the first conductor section and the second magnetic sensor group to detect the magnetic field to be measured in the second conductor section. These two magnetic fields to be measured form a differential magnetic field to be measured, which effectively improves the resistance of the current sensor to external magnetic field interference. The shielding cover effectively weakens or even eliminates electromagnetic interference from the surrounding environment without affecting the precise detection of the current to be measured, thereby avoiding abnormal saturation of the magnetic sensor unit caused by external interference and further improving the resistance of the current sensor to external magnetic field interference. A group of multiple magnetic sensors is arranged in the current sensor to ensure a high signal-to-noise ratio and high spatial fault tolerance, and to ensure high accuracy and low temperature drift of the current sensor in low-frequency and high-frequency current measurements. This achieves precise isolated detection of current and extends the measurement range. The current sensor provided by the embodiment of the present invention has a small size, strong interference resistance, a wide measurement range, low temperature drift, high-frequency response, and high measurement accuracy.

[0015] In order to more clearly describe the embodiments of the present invention or the technical solutions of the prior art, the accompanying drawings necessary for describing the embodiments or the prior art will be briefly described below. The accompanying drawings in the following description are specific embodiments of the present invention, but it is obvious to those skilled in the art that these embodiments can be extended and expanded to other structures and drawings based on the basic concepts of the device structure, driving method and manufacturing method disclosed and indicated by various embodiments of the present invention, which will undoubtedly fall within the scope of the claims of the present invention. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram illustrating a current sensor according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing the configuration of a current conductor to be measured according to an embodiment of the present invention; [Figure 3] 10 is a schematic diagram showing the configuration of another current conductor to be measured according to an embodiment of the present invention. FIG. [Figure 4] FIG. 2 is a schematic diagram illustrating another current sensor according to an embodiment of the present invention. [Figure 5] FIG. 10 is a schematic diagram illustrating yet another current sensor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and fully described through implementation examples in the embodiments of the present invention with reference to the accompanying drawings. Of course, the described embodiments are only a part of the embodiments of the present invention, and are not all of them. Based on the basic concepts disclosed and indicated by the embodiments of the present invention, all other embodiments obtained by those skilled in the art are within the protection scope of the present invention.

[0018] 1, which is a schematic diagram of a current sensor according to an embodiment of the present invention. The current sensor provided in this embodiment includes a current conductor 101 to be measured, the current conductor 101 comprising a first conductor section 102 and a second conductor section 103 of identical shape, where an area surrounded by the extended shapes of the first conductor section 102 and the second conductor section 103 is "U" shaped, and the first conductor section 102 and the second conductor section 103 are symmetrically distributed around a geometric centerline 104 of the current conductor 101 to be measured, and a first magnetic sensor group 105 and a second magnetic sensor group 106, where the first magnetic sensor group 105 is disposed on one or two sides of the first conductor section 102 and the second magnetic sensor group 106 is disposed on one or two sides of the second conductor section 103. the first magnetic sensor group 105 and the second magnetic sensor group 106 are arranged symmetrically around a geometric center line 104 of the current conductor 101 to be measured, and the first magnetic sensor group 105 and the second magnetic sensor group 106 have the same sensing direction; a signal processor 108, a circuit board 107, and a fully enclosed shielding cover 114, the shielding cover 114 being placed within a housing 115 and enclosing the current conductor 101 to be measured, the first magnetic sensor group 105, the second magnetic sensor group 106, the signal processor 108, and the circuit board 107, and the shielding cover 114, After a current flows through the current conductor 101 to be measured, the first conductor section 102 and the second conductor section 103 generate magnetic fields to be measured above and below the geometric centerline 104, respectively. The magnetic fields to be measured have the same magnitude and are distributed symmetrically in opposite directions around the geometric centerline 104 of the current conductor 101 to be measured. The first magnetic sensor group 105 is used to detect the first magnetic field to be measured generated by the current flowing through the first conductor section 102 of the current conductor 101 to be measured, and the second magnetic sensor group 106 is used to detect the second magnetic field to be measured generated by the current flowing through the second conductor section 103 of the current conductor 101 to be measured.The first magnetic field to be measured and the second magnetic field to be measured constitute a differential magnetic field to be measured. The differential magnetic field to be measured is converted into a differential voltage signal by the first magnetic sensor group 105 and the second magnetic sensor group 106. The differential voltage signal is processed by the signal processor 108 and converted into an output signal that is proportional to the current to be measured and changes in real time with the current to be measured. The output signal is output by a lead wire 109 connected to a circuit board 107.

[0019] In this embodiment, the first conductor section 102 and the second conductor section 103 have the same shape to form the current conductor 101 to be measured, which has a "U" shaped configuration.

[0020] 2, this figure is a schematic diagram of the shape of a current conductor to be measured according to one embodiment of the present invention. Optionally, the extension shapes of the first conductor section 102 and the second conductor section 103 are L-shaped, and the two form a "U"-shaped current conductor to be measured 101. The current conductor to be measured 101 has a geometric centerline 104, and the first conductor section 102 and the second conductor section 103 are distributed axially symmetrically about the geometric centerline 104.

[0021] 3, this figure is a schematic diagram of another configuration of a current conductor to be measured according to an embodiment of the present invention. Optionally, the extended shape of the first conductor section 102 and the second conductor section 103 resembles a Z-shape, and the two form the current conductor to be measured 101 shaped like a "U." The current conductor to be measured 101 has a geometric centerline 104, and the first conductor section 102 and the second conductor section 103 are distributed axially symmetrically about the geometric centerline 104.

[0022] It can be seen that the extension shape of the current conductor 101 to be measured may be U-shaped or similar to a U. Based on this, the first conductor section 102 and the second conductor section 103 may be reasonably selected to form the current conductor 101 to be measured. Here, the first conductor section 102 and the second conductor section 103 are not two independent conductor sections, but are parts of the current conductor 101 to be measured. Specifically, if the complete current conductor 101 to be measured is virtually divided, the U-shaped current conductor 101 to be measured may be divided into the first conductor section 102 and the second conductor section 103, which are symmetrical and have the same shape.

[0023] 1 , if the plane on which the U-shaped current conductor 101 to be measured is located is a horizontal plane XY, the first magnetic sensor group 105 and the second magnetic sensor group 106 are arbitrarily arranged on the same side of the plane XY as the current conductor 101 to be measured. In a direction Z perpendicular to the plane XY of the current conductor 101 to be measured, the first magnetic sensor group 105 overlaps the first conductor section 102 in a direction vertically projecting the plane XY on which the current conductor 101 to be measured is located. In other words, in the Z direction, the first magnetic sensor group 105 is located in an area above the first conductor section 102. The second magnetic sensor group 106 overlaps the second conductor section 103 in a direction vertically projecting the plane XY on which the current conductor 101 to be measured is located. In other words, in the Z direction, the second magnetic sensor group 106 is located in an area above the second conductor section 103.

[0024] The current sensor also includes a circuit board 107. Optionally, the first magnetic sensor group 105 and the second magnetic sensor group 106 are each configured as one magnetic sensor unit and are arranged symmetrically on the upper surface of the circuit board 107. Specifically, the first magnetic sensor group 105 and the second magnetic sensor group 106 are arranged on the upper surface of the circuit board 107, and the circuit board 107 is located between the magnetic sensor groups and the current conductor 101 to be measured. The upper surface of the circuit board 107 further includes a signal processor 108 and a lead wire 109. The first magnetic sensor group 105 and the second magnetic sensor group 106 are electrically connected to the signal processor 108 and the lead wire 109 through the circuit board 107, respectively. The first magnetic sensor group 105 and the second magnetic sensor group 106 located on the upper surface of the circuit board 107 are also distributed axially symmetrically around the geometric center line 104 of the current conductor 101 to be measured. The first magnetic sensor group 105 and the second magnetic sensor group 106 have the same sensing direction.

[0025] In other embodiments, the first group of magnetic sensors may also optionally be arranged on two sides of the first conductor section, and the second group of magnetic sensors may be arranged on two sides of the second conductor section.

[0026] The current conductor 101 to be measured is energized. Specifically, the current flows into the beginning of the first conductor section 102, passes through the first conductor section 102 and the second conductor section 103, and then flows out from the end of the second conductor section 103. As shown in FIG. 1 , the direction in which the current flows into the current conductor 101 to be measured is 110, and the direction in which the current flows out of the current conductor 101 to be measured is 111. As the current flows into the first conductor section 102, the first conductor section 102 generates a first magnetic field to be measured on two sides in the direction of the geometric centerline 104. The magnetic field direction of the first magnetic field to be measured at the position of the circuit board 107 is 112. As the current flows into the second conductor section 103, the second conductor section 103 generates a second magnetic field to be measured on two sides in the direction of the geometric centerline 104. The magnetic field direction of the second magnetic field to be measured at the location of the circuit board 107 is 113. The magnetic field direction 112 of the first magnetic field to be measured and the magnetic field direction 113 of the second magnetic field to be measured have the same magnitude but opposite directions, and the two magnetic field directions are further distributed symmetrically in opposite directions around the geometric centerline 104 of the current conductor 101 to be measured.

[0027] The first magnetic sensor group 105 and the second magnetic sensor group 106 have the same sensing direction, which is the same as the magnetic field direction 112 of the first magnetic field to be measured. The first magnetic sensor group 105 may be used to detect the first magnetic field to be measured generated by a current flowing through the first conductor section 102 of the current conductor 101 to be measured, and the second magnetic sensor group 106 may be used to detect the second magnetic field to be measured generated by a current flowing through the second conductor section 103 of the current conductor 101 to be measured. The first magnetic field to be measured and the second magnetic field to be measured form a differential magnetic field to be measured. The differential magnetic field to be measured is converted into a differential voltage signal by the first magnetic sensor group 105 and the second magnetic sensor group 106.

[0028] The current sensor further includes a signal processor 108. The signal processor 108 is electrically connected to the circuit board 107. A differential voltage signal converted and generated by the first magnetic sensor group 105 and the second magnetic sensor group 106 based on the first magnetic field to be measured and the second magnetic field to be measured is processed by the signal processor 108 and converted into an output signal that is proportional to the current to be measured and changes in real time in conjunction with the current to be measured. The output signal is output by a lead wire 109 connected to the circuit board 107.

[0029] The current sensor further includes a shielding cover 114 that is completely enclosed. The shielding cover 114 is placed inside a housing 115 made of an insulating material. The shielding cover 114 encloses the current conductor 101 to be measured, the first magnetic sensor group 105, the second magnetic sensor group 106, the signal processor 108, and the circuit board 107. The housing 115 made of an insulating material can improve the electrical safety of the current sensor. It should be noted that only a portion of the internal structure of the current sensor is shown in FIG. 1 . In reality, the entire internal structure of the current sensor is completely enclosed by the shielding cover 114, which is in turn enclosed by the insulating housing 115. It should be noted that the lead wire 109 connected to the circuit board 107 is led out of the housing 115 through the shielding cover 114.

[0030] Optionally, the current conductor 101 to be measured is a single-material metal conductor or a homogeneous alloy conductor, but is not limited thereto, and the material of the current conductor to be measured may be reasonably selected based on ensuring the function of the current conductor to be measured.

[0031] Optionally, the cross-sectional shape of the symmetric area of ​​the current conductor 101 to be measured is rectangular, trapezoidal, circular, or semicircular. That is, using the XZ plane for the cross sections of the first conductor section 102 and the second conductor section 103 of the current conductor 101 to be measured, the cross-sectional shape of the current conductor 101 to be measured may be arbitrary rectangular, trapezoidal, circular, or semicircular. However, without being limited thereto, the cross-sectional shape of the current conductor to be measured may be rationally designed based on ensuring the function of the current conductor to be measured.

[0032] Optionally, the material of the shielding cover is permalloy, silicon steel, pure iron, a magnetically conductive metal material, or an alloy, but is not limited thereto, and the material of the shielding cover may be reasonably selected based on ensuring the shielding function of the shielding cover.

[0033] Optionally, the first magnetic sensor group includes one or more magnetic sensor units, and the second magnetic sensor group includes one or more magnetic sensor units. Optionally, the magnetic sensor units are Hall sensors, anisotropic magnetic sensors, giant magnetic sensors, or tunnel magnetic sensors. However, without being limited thereto, the magnetic sensor units constituting the magnetic sensor groups may be rationally selected based on ensuring the functionality of the current sensor.

[0034] Optionally, the signal processor 108 includes a temperature compensation unit, a nonlinear compensation unit, and an operational amplifier. The differential voltage signals converted by the first magnetic sensor group 105 and the second magnetic sensor group 106 pass through the temperature compensation unit, the nonlinear compensation unit, and the operational amplifier in sequence to form an output signal of the current sensor.

[0035] In this embodiment, the signal processor 108 is electrically connected to the circuit board 107. The temperature compensation unit of the signal processor 108 performs temperature compensation on the voltage signals of the first magnetic sensor group 105 and the second magnetic sensor group 106. The nonlinear compensation unit performs nonlinear compensation on the temperature-compensated voltage signals. The operational amplifier performs gain amplification on the nonlinearly compensated voltage signals, thereby ensuring high accuracy and small temperature drift of the current sensors and achieving precise isolated detection of current. Optionally, the signal processor is a programmable adjustment chip that includes the temperature compensation unit and the nonlinear compensation unit.

[0036] In an embodiment of the present invention, the current conductor to be measured by the current sensor is U-shaped. The first magnetic sensor group is arranged on one or two sides of the first conductor section, and the second magnetic sensor group is arranged on one or two sides of the second conductor section. This eliminates the need for a magnetic flux collection structure, resulting in a small overall structure and low cost, while significantly improving the frequency response characteristics of the current sensor. The current sensor uses the first magnetic sensor group to detect the magnetic field to be measured in the first conductor section and the second magnetic sensor group to detect the magnetic field to be measured in the second conductor section. These two magnetic fields to be measured form a differential magnetic field to be measured, which effectively improves the resistance of the current sensor to external magnetic field interference. The shielding cover effectively weakens or even eliminates electromagnetic interference from the surrounding environment without affecting the precise detection of the current to be measured, thereby avoiding abnormal saturation of the magnetic sensor unit caused by external interference and further improving the resistance of the current sensor to external magnetic field interference. A group of multiple magnetic sensors is arranged in the current sensor to ensure a high signal-to-noise ratio and high spatial fault tolerance, and to ensure high accuracy and low temperature drift of the current sensor in low-frequency and high-frequency current measurements. This achieves precise isolated detection of current and extends the measurement range. The current sensor provided by the embodiment of the present invention has a small size, strong interference resistance, a wide measurement range, low temperature drift, high-frequency response, and high measurement accuracy.

[0037] For example, based on the above technical solution, optionally, the first and second magnetic sensor groups are symmetrically arranged on a circuit board, and the circuit board is symmetrically distributed on one or two sides of the current conductor to be measured. Each of the first and second magnetic sensor groups is composed of M magnetic sensor units arranged in parallel and spaced apart on one or two sides of the first conductor section. The magnetic sensor units are attached to the circuit board, where M is a positive integer. The output signal of the first and second magnetic sensor groups is each the average value of the converted signals of the M magnetic sensor units. The output signal of the first and second magnetic sensor groups forms a differential voltage signal.

[0038] In this embodiment, optionally, each of the first magnetic sensor group and the second magnetic sensor group is composed of M magnetic sensor units connected in parallel, where M is a positive integer.

[0039] 1, M=1, that is, the first magnetic sensor group 105 and the second magnetic sensor group 106 each consist of one magnetic sensor unit, and they are each symmetrically arranged on the upper surface of the circuit board 107. The first magnetic sensor group 105 and the second magnetic sensor group 106 have the same sensing direction.

[0040] Referring to FIG. 4, this figure is a schematic diagram of another current sensor according to an embodiment of the present invention. As shown in FIG. 4, M is greater than 1, and optionally M=3. A first magnetic sensor group is composed of three magnetic sensor units 405, 406, and 407 connected in parallel, and a second magnetic sensor group is composed of three magnetic sensor units 408, 409, and 410 connected in parallel, which are symmetrically distributed on the upper surface of a circuit board 411 with respect to the geometric centerline 404 of a current conductor 401 to be measured. The first magnetic sensor group and the second magnetic sensor group have the same sensing direction. Specifically, the magnetic sensor units 405, 406, 407, 408, 409, and 410 have the same sensing direction.

[0041] The circuit board 411 is disposed above the first and second conductor sections 402 and 403, which form a "U"-shaped current conductor 401 to be measured. A current 412 to be measured flows into the current conductor 401 to be measured in the direction of the arrows shown in the drawing, generating a first magnetic field to be measured and a second magnetic field to be measured above the first and second conductor sections 402 and 403, respectively. The two magnetic fields to be measured have the same magnitude and opposite direction and are distributed symmetrically around the geometric centerline 404 of the current conductor 401 to be measured, forming a differential magnetic field to be measured. The output signal of the first magnetic sensor group is the average value of the output signals of the three magnetic sensor units 405, 406, and 407, and the output signal of the second magnetic sensor group is the average value of the output signals of the three magnetic sensor units 408, 409, and 410. The output signals of the first magnetic sensor group and the output signals of the second magnetic sensor group form a differential magnetic field to be measured, and the differential magnetic field to be measured is converted into a differential voltage signal through the first magnetic sensor group and the second magnetic sensor group.

[0042] In this embodiment, multiple magnetic sensor units are arranged in a magnetic sensor cluster, which results in a high signal-to-noise ratio and high spatial fault tolerance in the measurement process, ensuring high accuracy and low temperature drift of the current sensor in low-frequency and high-frequency current measurement, thereby achieving precise isolated detection of current and extending the measurement range.

[0043] For example, based on the above technical solutions, the first magnetic sensor group may also be optionally arranged on two sides of the first conductor section, and the second magnetic sensor group may be arranged on two sides of the second conductor section. Referring to Fig. 5, this figure is a schematic diagram of yet another current sensor according to an embodiment of the present invention. The difference from Fig. 1 is that in the current sensor shown in Fig. 5, the first magnetic sensor group is composed of two magnetic sensor units 504 and 505 connected in parallel, and the second magnetic sensor group is composed of two magnetic sensor units 506 and 507 connected in parallel, which are symmetrically arranged on two circuit boards 508 and 509, respectively.

[0044] 5, the current conductor to be measured includes a first conductor section 501 and a second conductor section 502. The first conductor section 501 and the second conductor section 502 are symmetrically distributed around a geometric centerline 503 of the current conductor to be measured. Two magnetic sensor units 504 and 505 in the first magnetic sensor group are located above and below the plane on which the first conductor section 501 is located, and two magnetic sensor units 506 and 507 in the second magnetic sensor group are located above and below the plane on which the second conductor section 502 is located. The magnetic sensor units 504 and 506 have the same sensing direction, the magnetic sensor units 505 and 507 have the same sensing direction, and the magnetic sensor units 504 and 507 have opposite sensing directions.

[0045] Circuit board 508 is arranged above first conductor section 501 and second conductor section 502 that form a "U"-shaped current conductor to be measured, and circuit board 509 is arranged below first conductor section 501 and second conductor section 502 that form a "U"-shaped current conductor to be measured, with circuit boards 508 and 509 arranged symmetrically above and below first conductor section 501 and second conductor section 502. Optionally, magnetic sensor unit 504 and magnetic sensor unit 506 are located on an upper surface of circuit board 508, and magnetic sensor unit 505 and magnetic sensor unit 507 are located on a lower surface of circuit board 509.

[0046] A current to be measured flows into the first conductor section 501 in a current direction 510, and generates symmetrical but oppositely directed magnetic fields to be measured 512 and 513 above and below the first conductor section 501. The two magnetic fields to be measured 512 and 513 are distributed axially symmetrically around the first conductor section 501 and have the same magnitude and opposite directions, thus forming a differential magnetic field. A current to be measured flows out of the second conductor section 502 in a current direction 511, and generates symmetrical but oppositely directed magnetic fields to be measured 514 and 515 above and below the second conductor section 502. The two magnetic fields to be measured 514 and 515 are distributed axially symmetrically around the second conductor section 502 and have the same magnitude and opposite directions, thus forming a differential magnetic field.

[0047] The magnetic fields 512 and 513 to be measured and the magnetic fields 514 and 515 to be measured are symmetrically distributed around the geometric centerline 503 of the current conductor to be measured, have the same magnitude and opposite direction, and thus form a differential magnetic field to be measured. The output signal of the first magnetic sensor group is the average value of the differential magnetic field converted signals of the two magnetic sensor units 504 and 505, and the output signal of the second magnetic sensor group is the average value of the differential magnetic field converted signals of the two magnetic sensor units 506 and 507. The output signals of the first magnetic sensor group and the second magnetic sensor group constitute the differential magnetic field to be measured. The differential magnetic field to be measured is converted into a differential voltage signal through the first magnetic sensor group and the second magnetic sensor group.

[0048] The current sensor provided by the embodiments of the present invention has a small size, strong interference resistance, a wide measurement range, little temperature drift, high frequency response, and high measurement accuracy.

[0049] It should be noted that the above description is merely a preferred embodiment and technical principle of the present invention. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described herein, and that various obvious modifications, rearrangements, combinations, and substitutions may be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in detail through the above embodiments, the present invention is not limited to the above embodiments, and other equivalent embodiments may also be included without departing from the concept of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A current conductor to be measured having a U-shaped or U-like planar shape, wherein when the current conductor to be measured is virtually divided along the geometric center line of its planar shape, it includes a first conductor section and a second conductor section of identical shape, and the first conductor section and the second conductor section are distributed axially symmetrically around the geometric center line of the current conductor to be measured; a first group of magnetic sensors and a second group of magnetic sensors, the first group of magnetic sensors being arranged on both sides of a plane on which the first conductor section is located, and the second group of magnetic sensors being arranged on both sides of a plane on which the second conductor section is located, the first group of magnetic sensors and the second group of magnetic sensors being distributed axially symmetrically around the geometric center line of the current conductor to be measured, and the first group of magnetic sensors and the second group of magnetic sensors being arranged on the same side of the first conductor section and the second conductor section have the same sensing direction; a signal processor, a circuit board, and a fully enclosed shielding cover, the shielding cover being placed within a housing and enclosing the current conductor to be measured, the first group of magnetic sensors, the second group of magnetic sensors, the signal processor, and the circuit board; After a current flows through the current conductor to be measured, the first conductor section and the second conductor section generate magnetic fields to be measured above and below a plane on which they are located, respectively, and the magnetic fields to be measured have the same magnitude and the directions of the magnetic fields are symmetrically distributed in opposite directions around the geometric centerline of the current conductor to be measured, the first magnetic sensor group is used to detect the first magnetic field to be measured generated by the current flowing through the first conductor section of the current conductor to be measured, and the second magnetic sensor group is used to detect the second magnetic field to be measured generated by the current flowing through the second conductor section of the current conductor to be measured, the first magnetic field of the object to be measured and the second magnetic field of the object to be measured constitute a differential magnetic field of the object to be measured, the differential magnetic field of the object to be measured is converted into a differential voltage signal by the first magnetic sensor group and the second magnetic sensor group, the differential voltage signal is processed by the signal processor and converted into an output signal that is proportional to the current of the object to be measured and changes in real time in conjunction with the current of the object to be measured, and the output signal is output by a lead wire connected to the circuit board; the first magnetic sensor group and the second magnetic sensor group are each composed of M magnetic sensor units arranged in parallel and spaced apart on both sides of the first conductor section and the second conductor section, the magnetic sensor units being attached to the circuit board, M being a positive integer greater than 1, and the magnetic sensor units being distributed axially symmetrically around the geometric centerline of the current conductor to be measured; A current sensor, wherein the first group of magnetic sensors and the second group of magnetic sensors are arranged symmetrically on the circuit board, and the circuit board is distributed symmetrically on both sides of the current conductor to be measured.

2. The current sensor according to claim 1 , wherein the current conductor to be measured is a single-material metal conductor or a homogeneous alloy conductor.

3. The current sensor according to claim 1 , wherein the cross-sectional shape of the symmetrical area of ​​the current conductor to be measured is rectangular, trapezoidal, circular, or semicircular.

4. 2. The current sensor of claim 1, wherein the output signal of the first magnetic sensor group and the output signal of the second magnetic sensor group are each an average value of converted signals of the M magnetic sensor units, and the output signal of the first magnetic sensor group and the output signal of the second magnetic sensor group constitute a differential voltage signal.

5. The current sensor according to claim 4 , wherein the magnetic sensor unit is a Hall sensor, an anisotropic magnetic sensor, a giant magnetic sensor, or a tunnel magnetic sensor.

6. The current sensor according to claim 1 , wherein the material of the shielding cover is permalloy, silicon steel, pure iron, a magnetically conductive metal material, or an alloy.

7. 2. The current sensor of claim 1, wherein the signal processor comprises a temperature compensation unit, a nonlinear compensation unit, and an operational amplifier, and the differential voltage signal converted by the first group of magnetic sensors and the second group of magnetic sensors passes sequentially through the temperature compensation unit, the nonlinear compensation unit, and the operational amplifier to form the output signal of the current sensor.

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