A copper busbar current sensor

Abstract

The present invention relates to the technical field of current sensors, and specifically to a copper busbar current sensor, comprising: a first group of magnetic sensor chips, distributed on the first side of the copper busbar to be tested; a second group of magnetic sensor chips, distributed on the second side of the copper busbar to be tested, the second side is opposite to the first side, the second group of magnetic sensor chips and the first group of magnetic sensor chips contain the same magnetic sensor chips, and the number is equal, each magnetic sensor chip includes a first voltage terminal and a second voltage terminal; a programmable gain amplifier, including a common-phase input terminal and an inverting input terminal, wherein the first voltage terminal of the first group of magnetic sensor chips is connected to the common-phase input terminal, and the second voltage terminal of the first group of magnetic sensor chips is connected to the inverting input terminal; the first voltage terminal in the second group of magnetic sensor chips is connected to the inverting input terminal, and the second voltage terminal in the second group of magnetic sensor chips is connected to the common-phase input terminal. The copper busbar current sensor provided by the present invention has a compact structure and good frequency response characteristics.

Description

Technical Field

[0001] The invention relates to the technical field of current sensors, and in particular to a copper busbar current sensor. Background Art

[0002] In recent years, power electronic systems such as new energy vehicles, photovoltaic power stations, communication base stations, and energy storage are gradually developing towards modularization, integration, high power density, and small size. Copper busbars meet the development needs of power electronic systems due to their small size and strong current capacity.

[0003] Traditional current sensors usually use an iron core or a ring array composed of multiple Hall elements as a copper busbar current detection solution. On the other hand, there are also current sensors that use ring-shaped magnetic sensor chips to detect copper busbar current. For example, a current measuring device disclosed in Chinese patent application CN109374940A. However, the inventors found that the existing copper busbar current detection has the following problems:

[0004] On the one hand, for these current sensors using magnetic sensor chips, a ring array solution is usually adopted, which is relatively large in size, and due to the adhesion effect of the copper busbar, the high-frequency frequency characteristics of the existing copper busbar current detection are poor, which leads to low detection accuracy;

[0005] On the other hand, whether one or more magnetic sensor chips are used, the error of the magnetic sensor chip itself will affect the accuracy of the final detection result; therefore, some people have proposed a differential structure to reduce the impact of the error of the magnetic sensor chip itself on the detection result, but this method still has a problem. If the consistency between the magnetic sensor chips is poor (for example, the error of each magnetic sensor chip is different), even if the so-called differential structure is used, the accuracy of the detection result will still be affected because the differences between the magnetic sensor chips cannot be eliminated. Summary of the invention

[0006] In view of this, an embodiment of the present invention provides a copper busbar current sensor to solve the problem of low current detection accuracy due to the high-frequency adhesion effect of the copper busbar in the prior art.

[0007] According to a first aspect, an embodiment of the present invention provides a copper busbar current sensor, comprising: a first group of magnetic sensor chips, distributed on a first side of the copper busbar to be tested; a second group of magnetic sensor chips, distributed on a second side of the copper busbar to be tested, the second side being opposite to the first side, the second group of magnetic sensor chips being the same as the magnetic sensor chips included in the first group of magnetic sensor chips, and being equal in number, each of the magnetic sensor chips comprising a first voltage terminal and a second voltage terminal; a programmable gain amplifier comprising a non-inverting input terminal and an inverting input terminal, wherein the first voltage terminal in the first group of magnetic sensor chips is connected to the non-inverting input terminal, and the second voltage terminal in the first group of magnetic sensor chips is connected to the inverting input terminal; the first voltage terminal in the second group of magnetic sensor chips is connected to the inverting input terminal, and the second voltage terminal in the second group of magnetic sensor chips is connected to the non-inverting input terminal.

[0008] Optionally, the magnetic sensor chip includes: a first magnetic resistor, a second magnetic resistor, a third magnetic resistor and a fourth magnetic resistor, wherein one end of the first magnetic resistor is connected to one end of the fourth magnetic resistor and connected to the power supply terminal of the magnetic sensor chip; the other end of the first magnetic resistor is connected to one end of the second magnetic resistor and connected to the first voltage terminal of the magnetic sensor chip; the other end of the second magnetic resistor is connected to one end of the third magnetic resistor and connected to the ground terminal of the magnetic sensor chip; the other end of the third magnetic resistor is connected to the other end of the fourth magnetic resistor and connected to the second voltage terminal of the magnetic sensor chip.

[0009] Optionally, the magnetic sensor chips included in the second group of magnetic sensor chips and the first group of magnetic sensor chips are arranged in the same direction relative to the copper bus to be tested.

[0010] Optionally, the second group of magnetic sensor chips and the first group of magnetic sensor chips both include two magnetic sensor chips.

[0011] Optionally, the first group of magnetic sensor chips, the second group of magnetic sensor chips and the programmable gain amplifier are all arranged on a circuit board, and the first group of magnetic sensor chips and the second group of magnetic sensor chips are connected to the programmable gain amplifier through the circuit board.

[0012] Optionally, the circuit board is a U-shaped circuit board, the copper bus to be tested is arranged in a U-shaped groove of the U-shaped circuit board, the first group of magnetic sensor chips is arranged on the circuit board on the first side of the U-shaped groove, and the second group of magnetic sensor chips is arranged on the circuit board on the second side of the U-shaped groove.

[0013] Optionally, a communication interface is further provided on the circuit board and connected to the output end of the programmable gain amplifier, and the communication interface is used to connect to an external device.

[0014] Optionally, the copper busbar current sensor further comprises: a sensor housing, a detachable cover plate is provided on one side of the sensor housing, and the circuit board is detachably installed in the sensor housing.

[0015] Optionally, a shielding shell with an opening on one side is further disposed in the sensor housing, the circuit board is disposed in the shielding shell, and an insulating layer is disposed between the shielding shell and the circuit board.

[0016] Optionally, a flange is provided on the sensor housing, and a first screw hole is provided on the flange; a second screw hole corresponding to the first screw hole is provided on the copper bus to be tested, and the copper bus current sensor is fixed to the copper bus to be tested by screws passing through the first screw hole and the second screw hole.

[0017] The present invention has the following beneficial effects:

[0018] The copper busbar current sensor provided by the embodiment of the present invention is provided with symmetrically distributed magnetic sensor chips on the first side and the second side of the copper busbar to be tested, and the first voltage end of the first group of magnetic sensor chips is connected to the in-phase input end of the programmable gain amplifier, and the second voltage end is connected to the inverting input end of the programmable gain amplifier, and the first voltage end and the second voltage end of the second group of magnetic sensor chips are respectively connected to the inverting input end and the in-phase input end of the programmable gain amplifier, that is, the connection mode of the first group of magnetic sensor chips and the programmable gain amplifier and the connection mode of the second group of magnetic sensor chips and the programmable gain amplifier are reversed. Through the arrangement mode of the above-mentioned components, the positions of multiple sensor chips relative to the copper busbar are optimized, and the influence of the adhesion effect of the copper busbar on the detection results is reduced, thereby ensuring the good frequency characteristics of the copper busbar current sensor of the present invention.

[0019] Furthermore, since the connection method of the first group of magnetic sensor chips and the programmable gain amplifier is reversed, the influence of the differences in the magnetic sensor chip devices themselves on the detection results can be reduced, the problem of low detection accuracy caused by poor consistency of the magnetic sensor chips is solved, thereby improving the accuracy of detection.

[0020] The copper busbar current sensor provided in the embodiment of the present invention uses a first magnetic resistor, a second magnetic resistor, a third magnetic resistor and a fourth magnetic resistor to detect the magnetic field around the copper busbar to be tested, thereby obtaining the current passing through the copper busbar to be tested. Compared with traditional current detection, there is no need to use an iron core, a magnetic core, etc., which reduces the hysteresis loss of the current sensor under high-frequency current, making the detection more accurate.

[0021] In the copper busbar current sensor provided by the embodiment of the present invention, the second group of magnetic sensor chips and the magnetic sensor chips included in the first group of magnetic sensor chips maintain the same direction relative to the copper busbar to be tested.

[0022] When the current frequency increases, the detection results at different positions vary greatly. Therefore, the embodiment of the present invention uses four magnetic sensor chips to detect four different positions around the copper bus to be tested, avoiding the problem of large differences in detection results caused by using an odd number of magnetic sensor chips or traditional solutions for detection, thereby improving the detection accuracy.

[0023] The copper busbar current sensor provided in the example of the present invention welds the first group of magnetic sensor chips, the second group of magnetic sensor chips and the programmable gain amplifier on a circuit board, which is convenient to install, highly integrated and small in size, and can meet the detection requirements of small-volume copper busbars.

[0024] The copper busbar current sensor provided in the example of the present invention uses a U-shaped circuit board to set the magnetic sensor chip around the copper busbar to be tested for detection. It has a simple structure, is easy to disassemble, has high integration, and is small in size, and can meet the detection needs of small-volume copper buses.

[0025] The copper busbar current sensor provided by the example of the present invention transmits the output result of the programmable gain amplifier to an external device by setting a communication interface, which is convenient for use.

[0026] The copper busbar current sensor provided in the example of the present invention encapsulates a magnetic sensor chip and a programmable gain amplifier through a sensor housing, a shielding shell, and an insulating layer, so that the structure of the current sensor is more compact and the installation flexibility is higher. By arranging a flange structure on the sensor housing and opening a first screw hole on the flange structure, the current sensor can be fixed on the copper busbar to be tested with screws, which has high reliability and is easy to install. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 is a schematic diagram of a copper busbar current sensor provided according to an embodiment of the present invention;

[0029] Figure 2 It is a schematic diagram of the magnetic field distribution around the copper bus to be tested;

[0030] Figure 3 is a schematic diagram of the composition of a magnetic sensor chip 30 provided according to an embodiment of the present invention;

[0031] Figure 4is a connection diagram of four magnetic sensor chips 30 provided in an embodiment of the present invention;

[0032] Figure 5 is a schematic diagram of a circuit board 50 provided according to an embodiment of the present invention;

[0033] Figure 6 is a schematic diagram of a U-shaped circuit board provided according to an embodiment of the present invention;

[0034] Figure 7 is a schematic diagram of the position distribution of four magnetic sensor chips provided according to an embodiment of the present invention;

[0035] Figure 8 is a schematic diagram of a sensor housing 70 provided according to an embodiment of the present invention;

[0036] Fig. 9 is a schematic diagram of a shielding shell 80 provided according to an embodiment of the present invention;

[0037] Fig. 10A is a front schematic diagram of a copper busbar current sensor provided according to an embodiment of the present invention;

[0038] Fig. 10B 2 is a schematic diagram of the reverse side of the copper busbar current sensor provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0040] The inventors have found that current sensors using magnetic sensor chips usually adopt a ring array solution, which is relatively large in size. In addition, due to the adhesion effect of the copper busbar, the high-frequency frequency characteristics of the existing copper busbar current detection are poor, which leads to low detection accuracy.

[0041] Although the magnetic sensor chips used in the current sensor are the same chip, during use, different magnetic sensor chips will produce different errors due to the influence of different usage scenarios and environmental factors. This will cause the current sensor to be used continuously. Due to the differences between the magnetic sensor chips, the accuracy of the current sensor detection results will gradually decrease. That is, during detection, since the errors of each magnetic sensor chip are not completely consistent, the sensor detection results are affected by the differences in the magnetic sensor chips, which ultimately affects the accuracy of the detection results.

[0042] Therefore, the embodiment of the present invention provides a copper busbar current sensor, such as Figure 1 As shown, the copper busbar current sensor includes: a first group of magnetic sensor chips 10, distributed on the first side of the copper busbar 01 to be tested; a second group of magnetic sensor chips 20, distributed on the second side of the copper busbar 01 to be tested, the second side is opposite to the first side, the second group of magnetic sensor chips 20 are the same as the magnetic sensor chips 30 included in the first group of magnetic sensor chips 10, and the number is equal, each of the magnetic sensor chips 30 includes a first voltage terminal 31 and a second voltage terminal 32; a programmable gain amplifier 40, including a non-inverting input terminal (+) and an inverting input terminal (-), wherein the first voltage terminal 31 in the first group of magnetic sensor chips 10 is connected to the non-inverting input terminal, and the second voltage terminal 32 in the first group of magnetic sensor chips 10 is connected to the inverting input terminal; the first voltage terminal 31 in the second group of magnetic sensor chips 20 is connected to the inverting input terminal, and the second voltage terminal 32 in the second group of magnetic sensor chips 20 is connected to the non-inverting input terminal.

[0043] Figure 1 is a schematic diagram of a copper busbar current sensor provided according to an embodiment of the present invention, such as Figure 1 As shown, the current sensor includes a first group of magnetic sensor chips 10 and a second group of magnetic sensor chips 20, which are symmetrically arranged on both sides of the two long sides of the longitudinal cross-section shape of the copper busbar 01 to be tested, and the distances from each of the magnetic sensor chips 30 to the long side and the short side of the longitudinal cross-section of the copper busbar 01 to be tested are equal. The magnetic sensitive directions of the magnetic sensor chips 30 on the first side and the second side are opposite. The number of magnetic sensor chips included in the first group of magnetic sensor chips 10 and the second group of magnetic sensor chips 20 is consistent and symmetrically distributed. Specifically, the first group of magnetic sensor chips 10 includes 1, 2, 3... magnetic sensor chips, and the second group of magnetic sensor chips 20 also includes 1, 2, 3... magnetic sensor chips, and so on. Figure 2 The magnetic field distribution around the copper bus 01 to be tested is shown in Fig. Figure 2 It can be seen that the closer to the surface of the copper busbar 01 to be tested, the greater the magnetic flux density and the greater the current.

[0044] The programmable gain amplifier 40 has a non-inverting input terminal (+) and an inverting input terminal (-). The first voltage terminal 31 of the first group of magnetic sensor chips 10 and the second voltage terminal 32 of the second group of magnetic sensor chips 20 are connected to the non-inverting input terminal, and the second voltage terminal 32 of the first group of magnetic sensor chips 10 and the first voltage terminal 31 of the second group of magnetic sensor chips 20 are connected to the inverting input terminal. This is equivalent to connecting the magnetic sensor chips 30 of the first group of magnetic sensor chips 10 and the second group of magnetic sensor chips 20 in parallel and then connecting them to the programmable gain amplifier 40.

[0045] The copper busbar current sensor provided by the embodiment of the present invention is configured by respectively arranging symmetrically distributed magnetic sensor chips on the first side and the second side of the copper busbar to be measured, and connecting the first voltage end of the first group of magnetic sensor chips to the in-phase input end of the programmable gain amplifier, and connecting the second voltage end to the inverting input end of the programmable gain amplifier, and connecting the first voltage end and the second voltage end of the second group of magnetic sensor chips to the inverting input end and the in-phase input end of the programmable gain amplifier, respectively, that is, the connection mode of the first group of magnetic sensor chips to the programmable gain amplifier and the connection mode of the second group of magnetic sensor chips to the programmable gain amplifier are reversed.

[0046] The present invention example optimizes the positions of multiple sensor chips relative to the copper busbar to ensure good frequency characteristics of the sensor of the present invention. In the embodiment of the present invention, by using Maxwell's equations, the frequency characteristics of a single chip placed at different positions of the copper busbar are compared, so as to set the position of the chip of the present example relative to the copper busbar, so that symmetrically distributed magnetic sensor chips are respectively set on the first side and the second side of the copper busbar to be tested, and the connection mode of the first group of magnetic sensor chips and the programmable gain amplifier is reversed from the connection mode of the second group of magnetic sensor chips and the programmable gain amplifier, so as to reduce the influence of the adhesion effect of the copper busbar on the detection result and achieve good frequency characteristics.

[0047] Furthermore, another inventive point of the embodiment of the present invention is that reversing the connection method of the first group of magnetic sensor chips and the programmable gain amplifier and the connection method of the second group of magnetic sensor chips and the programmable gain amplifier can reduce the impact of the differences in the magnetic sensor chip devices themselves on the detection results, solve the problem of low detection accuracy caused by poor consistency of the magnetic sensor chips, and improve the accuracy of detection.

[0048] Alternatively, if Figure 3 As shown, the magnetic sensor chip 30 includes: a first magnetic resistor R1, a second magnetic resistor R2, a third magnetic resistor R3 and a fourth magnetic resistor R4, wherein one end of the first magnetic resistor R1 is connected to one end of the fourth magnetic resistor R4, and is connected to the power supply terminal VCC of the magnetic sensor chip 30; the other end of the first magnetic resistor R1 is connected to one end of the second magnetic resistor R2, and is connected to the first voltage terminal 31 of the magnetic sensor chip 30; the other end of the second magnetic resistor R2 is connected to one end of the third magnetic resistor R3, and is connected to the ground terminal GND of the magnetic sensor chip 30; the other end of the third magnetic resistor R3 is connected to the other end of the fourth magnetic resistor R4, and is connected to the second voltage terminal 32 of the magnetic sensor chip 30.

[0049] When the copper busbar 01 to be tested is energized, the first magnetic resistor R1, the second magnetic resistor R2, the third magnetic resistor R3 and the fourth magnetic resistor R4 are affected by the magnetic field at their locations, resulting in a change in the output voltage between the first voltage terminal 31 and the second voltage terminal 32. The magnitude of the magnetic field at the location can be obtained based on the output voltage, and then the current value of the copper busbar 01 to be tested can be obtained.

[0050] The first magnetoresistance R1, the second magnetoresistance R2, the third magnetoresistance R3 and the fourth magnetoresistance have consistent characteristics under ideal conditions or in a zero magnetic flux state (initial state), that is, R1=R2=R3=R4.

[0051] Figure 4 The copper busbar current sensor includes four magnetic sensor chips 30. As shown in the figure, the first voltage terminals V1+, V2+ of the first magnetic sensor chip A and the second magnetic sensor chip B, the first voltage terminals V3-, V4- of the third magnetic sensor chip C and the fourth magnetic sensor chip D are connected to the in-phase input terminal of the programmable gain amplifier 40, and the second voltage terminals V1-, V2-, the first voltage terminals V3+, V4+ of the third magnetic sensor chip C and the fourth magnetic sensor chip D are connected to the inverting input terminal of the programmable gain amplifier 40, which can also be understood as V1+, V2+, V 3-, V4- are connected in parallel and connected to the non-inverting input terminal of the programmable gain amplifier 40, and V1-, V2-, V3+, and V4+ are connected in parallel and connected to the inverting input terminal of the programmable gain amplifier 40; B1, B2, B3, and B4 represent the magnetic flux density of the first magnetic sensor chip A, the second magnetic sensor chip B, the third magnetic sensor chip C, and the fourth magnetic sensor chip D, respectively. B1 and B2, B3 and B4 have the same value in the same direction, and the values ​​of B1 and B3 are equal and opposite in direction. The output voltages of the first voltage terminal and the second voltage terminal can be expressed by the following formula:

[0052]

[0053] Then, the output terminal of the programmable gain amplifier 40 can be expressed as:

[0054]

[0055] Among them, B=B1=B2=-B3=-B4, K A , K B , K C , K D represent the gain of the programmable gain amplifier 40, S A , S B , S C , S D Respectively represent the sensitivity of the first magnetic sensor chip A to the fourth magnetic sensor chip D, KI represents the proportionality coefficient between the current and the magnetic flux density B, which depends on the distance between the magnetic sensor chip and the surface of the copper busbar 01 to be tested. I1, I2, I3, and I4 respectively represent the current values ​​of the copper busbar 01 to be tested detected by the first magnetic sensor chip A to the fourth magnetic sensor chip D, which can be obtained by inverse calculation using formula (1).

[0056] The copper busbar current sensor provided in the embodiment of the present invention uses a first magnetic resistor, a second magnetic resistor, a third magnetic resistor and a fourth magnetic resistor to detect the magnetic field around the copper busbar to be tested, thereby obtaining the current passing through the copper busbar to be tested. Compared with traditional current detection, there is no need to use an iron core, a magnetic core, etc., which reduces the hysteresis loss of the current sensor under high-frequency current, making the detection more accurate.

[0057] Alternatively, if Figure 1 As shown, the second group of magnetic sensor chips 20 and the magnetic sensor chips 30 included in the first group of magnetic sensor chips 10 are arranged in the same direction relative to the copper busbar 01 to be tested.

[0058] like Figure 1 As shown, since the magnetic field directions on the first side and the second side of the copper busbar 01 to be tested are opposite, the magnetic flux density directions of the magnetic sensor chip 30 are opposite. Therefore, the setting directions of the magnetic sensor chips 30 included in the second group of magnetic sensor chips 20 and the first group of magnetic sensor chips 10 are kept consistent with each other relative to the copper busbar 01 to be tested, ensuring that the values ​​of the input terminals of the programmable gain amplifier 40 are all positive values, thereby simplifying the subsequent calculation process.

[0059] Optionally, the second group of magnetic sensor chips 20 and the first group of magnetic sensor chips 10 both include two magnetic sensor chips 30 .

[0060] In a specific embodiment, the number of magnetic sensor chips 30 included in the second group of magnetic sensor chips 20 and the first group of magnetic sensor chips 10 is 2, and the distances of each magnetic sensor chip 30 from the long side and the short side of the longitudinal cross section of the copper bar 01 to be tested are equal, and the setting direction relative to the copper bar 01 is consistent, that is, the orientation of the first voltage terminal 31 and the second voltage terminal 32 is consistent, so as to detect the current at four different positions of the copper bar 01 to be tested, and ensure the accuracy of the detection. In the embodiment of the present invention, each group of magnetic sensor chips uses 2 chips, with the minimum number of magnetic sensor chips, and then reduces the influence caused by the difference of the magnetic sensor chip itself by reverse connection, so as to reduce the cost of the current sensor, and improve the accuracy of the detection result. However, it should be noted that in the embodiment of the present invention, each group of magnetic sensor chips can be 3, 4 or more, and 2 are just the optimal embodiment adopted by the present invention.

[0061] Alternatively, if Figure 5As shown, the first group of magnetic sensor chips 10 and the second group of magnetic sensor chips 20 and the programmable gain amplifier 40 are all arranged on a circuit board 50, and the first group of magnetic sensor chips 10 and the second group of magnetic sensor chips 20 are connected to the programmable gain amplifier 40 through the circuit board 50.

[0062] like Figure 5 As shown, the circuit board 50 has a through hole 51, and the first group of magnetic sensor chips 10 and the second group of magnetic sensor chips 20 are respectively arranged on both sides of the through hole. When performing detection, the copper bus 01 to be tested is arranged in the through hole to perform current detection.

[0063] The copper busbar current sensor provided in the embodiment of the present invention welds the first group of magnetic sensor chips, the second group of magnetic sensor chips and the programmable gain amplifier on a circuit board, which is convenient to install, has high integration and small size, and can meet the current detection requirements of small-volume copper busbars.

[0064] Alternatively, if Figure 6 As shown, the circuit board 50 is a U-shaped circuit board, the copper bus 01 to be tested is mounted in a U-shaped groove of the U-shaped circuit board, the first group of magnetic sensor chips 10 is arranged on the circuit board on the first side of the U-shaped groove, and the second group of magnetic sensor chips 20 is arranged on the circuit board on the second side of the U-shaped groove.

[0065] like Figure 6 As shown, four magnetic sensor chips 30 and a programmable gain amplifier 40 are welded on the circuit board 50. The first group of magnetic sensor chips 10 and the second group of magnetic sensor chips 20 each include two magnetic sensor chips 30, which are symmetrically arranged on the circuit board on the first side and the second side of the U-shaped groove, respectively. Figure 7 FIG. 4 shows a schematic diagram of the position distribution of the four magnetic sensor chips 30. Figure 7 As shown, the longitudinal cross-sectional dimension a*b of the copper bar 01 to be tested is 20mm*3mm, and the coordinates of the four magnetic sensor chips 30 are (6.7, 5.2), (-6.7, 5.2), (-6.7, -5.2) and (6.7, -5.2), respectively, that is, the distance between each magnetic sensor chip 30 and the surface of the copper bar 01 to be tested is 5.2mm, and the distance d between each magnetic sensor chip 30 and the short side of the longitudinal cross-sectional dimension of the copper bar 01 to be tested is 1 / 6 of the long side a. This position distribution enables the detection value of the magnetic sensor chip 30 to not decay with the increase of the frequency, that is, at this position, the magnetic sensor chip 30 has a good frequency characteristic.

[0066] The copper busbar current sensor provided in the embodiment of the present invention uses a U-shaped circuit board to set a magnetic sensor chip around the copper busbar to be tested for detection. It has a simple structure, is easy to disassemble, has a high degree of integration, and a small size, and can meet the detection requirements of small-volume copper buses.

[0067] Alternatively, if Figure 6 As shown, the circuit board 50 is provided with a communication interface 60 connected to the output end of the programmable gain amplifier 40 , and the communication interface 60 is used to connect to an external device.

[0068] Alternatively, if Figure 8 As shown, the copper busbar current sensor further includes: a sensor housing 70 , a detachable cover plate 71 is provided on one side of the sensor housing 70 , and the circuit board 50 is detachably installed in the sensor housing 70 .

[0069] like Figure 8 As shown, the sensor housing 70 is provided with a protrusion, and the cover plate 71 includes four side walls to form a barrel-shaped structure. At least two side walls are provided with recesses matching the protrusion, and the recess can penetrate the cover plate. By matching the protrusion with the recess, the cover plate 71 can encapsulate the opening of the sensor housing 70. The shape of the sensor housing 70 matches the shape of the circuit board 50. Optionally, another embodiment (not shown) can be adopted. The opening of the sensor housing 70 is provided with a groove matching the cover plate 71. During assembly, the opening of the sensor housing 70 is sealed by inserting the cover plate 71 into the groove; during disassembly, the cover plate 71 is pulled out of the groove to open the sensor housing 70, so that the disassembly of the cover plate 71 can be achieved.

[0070] Alternatively, if Fig. 9 As shown, a shielding shell 80 with an opening on one side is further disposed in the sensor housing 70 , the circuit board 50 is disposed in the shielding shell 80 , and an insulating layer is disposed between the shielding shell 80 and the circuit board 50 .

[0071] Specifically, the shielding shell 80 is a U-shaped shielding shell, the material of which can be copper. An insulating layer is laid on the bottom of the shielding shell 80 to isolate the circuit board 50 from the shielding shell 80. The insulating layer is an insulating tape. The circuit board 50 is fixed in the shielding shell 80 by applying 4500 glue and soldering. The shielding shell 80 is fixed in the sensor housing 70 by injecting 4500 glue.

[0072] Optionally, respectively Figure 8 , Fig. 10A , Fig. 10B As shown, the sensor housing 70 is provided with a flange 90, and the flange 90 is provided with a first screw hole 91; the copper busbar 01 to be tested is provided with a second screw hole 92 corresponding to the first screw hole 91, and the copper busbar current sensor is fixed to the copper busbar 01 to be tested by screws passing through the first screw hole 91 and the second screw hole 92.

[0073] Specifically, Fig. 10A , Fig. 10B It is a schematic diagram of the front and back sides of the copper busbar current sensor provided according to an embodiment of the present invention. Two first screw holes 91 are provided on the flange of the sensor housing 70, and two second screw holes 92 corresponding to the first screw holes 91 are provided on the copper busbar 01 to be tested. The copper busbar current sensor can be fixed on the copper busbar 01 to be tested by two M3 screws.

[0074] The copper busbar current sensor provided in the embodiment of the present invention encapsulates a magnetic sensor chip and a programmable gain amplifier through a sensor housing, a shielding shell, and an insulating layer, so that the structure of the current sensor is more compact and the installation flexibility is higher. By arranging a flange structure on the sensor housing and opening a first screw hole on the flange structure, the current sensor can be fixed on the copper busbar to be tested by using screws, so that the reliability is high and the installation is easy.

[0075] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A copper busbar current sensor, characterized in that: include: The first group of magnetic sensor chips is distributed on the first side of the copper bus to be tested; A second group of magnetic sensor chips are distributed on a second side of the copper busbar to be tested, the second side is opposite to the first side, the second group of magnetic sensor chips are the same as the first group of magnetic sensor chips, and the number of magnetic sensor chips is equal, and each of the magnetic sensor chips includes a first voltage terminal and a second voltage terminal; A programmable gain amplifier, comprising a non-inverting input terminal and an inverting input terminal, wherein a first voltage terminal in the first group of magnetic sensor chips is connected to the non-inverting input terminal, and a second voltage terminal in the first group of magnetic sensor chips is connected to the inverting input terminal; The first voltage terminal in the second group of magnetic sensor chips is connected to the inverting input terminal, and the second voltage terminal in the second group of magnetic sensor chips is connected to the non-inverting input terminal.

2. The copper busbar current sensor according to claim 1, characterized in that: The magnetic sensor chip includes: a first magnetic resistor, a second magnetic resistor, a third magnetic resistor and a fourth magnetic resistor, wherein: One end of the first magnetic resistor is connected to one end of the fourth magnetic resistor and is also connected to a power supply end of the magnetic sensor chip; The other end of the first magnetic resistor is connected to one end of the second magnetic resistor and is connected to the first voltage end of the magnetic sensor chip; The other end of the second magnetic resistor is connected to one end of the third magnetic resistor and is connected to the ground end of the magnetic sensor chip; The other end of the third magnetic resistor is connected to the other end of the fourth magnetic resistor and is also connected to the second voltage end of the magnetic sensor chip.

3. The copper busbar current sensor according to claim 1, characterized in that: The magnetic sensor chips included in the second group of magnetic sensor chips and the first group of magnetic sensor chips are arranged in the same direction relative to the copper bus to be tested.

4. The copper busbar current sensor according to any one of claims 1 to 3, characterized in that: The second group of magnetic sensor chips and the first group of magnetic sensor chips both include two magnetic sensor chips.

5. The copper busbar current sensor according to claim 1, characterized in that: The first group of magnetic sensor chips, the second group of magnetic sensor chips and the programmable gain amplifier are all arranged on a circuit board, and the first group of magnetic sensor chips and the second group of magnetic sensor chips are connected to the programmable gain amplifier through the circuit board.

6. The copper busbar current sensor according to claim 5, characterized in that: The circuit board is a U-shaped circuit board, the copper bar to be tested is arranged in a U-shaped groove of the U-shaped circuit board, the first group of magnetic sensor chips is arranged on the circuit board on the first side of the U-shaped groove, and the second group of magnetic sensor chips is arranged on the circuit board on the second side of the U-shaped groove.

7. The copper busbar current sensor according to claim 5, characterized in that: The circuit board is also provided with a communication interface connected to the output end of the programmable gain amplifier, and the communication interface is used to connect to an external device.

8. The copper busbar current sensor according to any one of claims 5 to 7, characterized in that: Also includes: A sensor housing is provided with a detachable cover plate on one side of the sensor housing, and the circuit board is detachably installed in the sensor housing.

9. The copper busbar current sensor according to claim 8, characterized in that: A shielding shell with an opening on one side is also arranged in the sensor housing, the circuit board is arranged in the shielding shell, and an insulating layer is arranged between the shielding shell and the circuit board.

10. The copper busbar current sensor according to claim 8, characterized in that: The sensor housing is provided with a flange, and the flange is provided with a first screw hole; the copper busbar to be tested is provided with a second screw hole corresponding to the first screw hole, and the copper busbar current sensor is fixed to the copper busbar to be tested by screws passing through the first screw hole and the second screw hole.

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