Current measurement module and current measurement device

Abstract

The invention provides a current measurement module and a current measurement device. A current measurement module is provided with: a conductor having two main bodies arranged in parallel in a first direction, and two current paths arranged in parallel in a second direction orthogonal to the first direction across a through hole and connecting the two main bodies; and two magnetic detection elements which are arranged in parallel in the second direction, each magnetic detection element having a magnetic induction surface that detects a component in a third direction orthogonal to the first direction and the second direction in a magnetic field generated by the current flowing through the two current paths, and which detects a component in the magnetic field generated by the current flowing through the two current paths when viewed from the third direction. The two magnetic detection elements are disposed on the inside of the through hole, and in the second direction, the center position of the two magnetic detection elements is closer to one of the two current paths.

Description

Technical Field

[0001] The invention relates to a current measuring module and a current measuring device. Background Art

[0002] Patent Document 1 discloses a “sensing system for sensing a current flowing through a conductor in a non-contact manner”.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent Application Publication No. 2023 / 0204632 Summary of the invention

[0006] In a first aspect of the present invention, a current measuring module is provided. The current measuring module comprises: a conductor having two main bodies and two current paths, the two main bodies being arranged in parallel in a first direction, the two current paths being arranged in parallel in a second direction orthogonal to the first direction with a through hole therebetween, and connecting the two main bodies; and two magnetic detection elements having magnetic sensing surfaces and arranged in parallel in the second direction, the magnetic sensing surfaces detecting a component in a third direction orthogonal to the first direction and the second direction in a magnetic field generated by currents flowing through the two current paths, the two magnetic detection elements being arranged on the inner side of the through hole when viewed from the third direction, and the center position between the two magnetic detection elements being close to either of the two current paths in the second direction.

[0007] A center distance between the two magnetic detection elements in the second direction may be greater than 2 mm.

[0008] A distance between the two magnetic detection elements in the second direction may be equal to or greater than 15% of a width of the through hole in the second direction.

[0009] The width of each of the two current paths in the second direction may be less than or equal to 20% of the width of the conductor in the second direction.

[0010] The width of each of the two current paths in the second direction may be less than 4 mm.

[0011] The widths of the two current paths in the second direction may be the same.

[0012] The positions of the magnetic sensitivity surfaces of the two magnetic detection elements in the third direction may be within a range of 4 mm from the upper surfaces of the two current paths.

[0013] The width of the conductor in the third direction may be less than or equal to 4 mm.

[0014] The current path closer to the center position between the two magnetic detection elements in the second direction may be the first current path, and the two magnetic detection elements may be separated from inner ends of the first current path by 1 mm or more.

[0015] It is also possible that a current path that is closer to the center position between the two magnetic detection elements in the second direction is set as a first current path, and the center distance between the two magnetic detection elements is greater than the distance between the center position of the magnetic detection element on the first current path side of the two magnetic detection elements and the end of the first current path.

[0016] The two magnetic detection elements may be arranged to be opposed to each other with respect to the center of the through hole in the second direction.

[0017] In the second direction, when current flows through the conductor, magnetic fields received from the two current paths cancel each other, and the two magnetic detection elements may be disposed opposite to each other across a region where the magnetic flux density detected in the third direction is zero.

[0018] The two magnetic detection elements mentioned above may be Hall elements.

[0019] An insulating member may be further provided, the insulating member fixing the two magnetic detection elements to the conductor.

[0020] The device may further include a substrate that fixes the two magnetic detection elements to the conductor.

[0021] In a second aspect of the present invention, a current measuring device is provided. The current measuring device includes three of the above-mentioned arbitrary current measuring modules, and the current measuring modules are arranged in parallel in the above-mentioned second direction. In the above-mentioned second direction, the center positions of the two magnetic detection elements of the above-mentioned current measuring module arranged on the left side are arranged at a position close to the current path on the side of the above-mentioned current measuring module arranged in the center, the center positions of the two magnetic detection elements of the above-mentioned current measuring module arranged in the center are arranged at a position close to the current path on the side of the above-mentioned current measuring module arranged on the right side, and the center positions of the two magnetic detection elements of the above-mentioned current measuring module arranged on the right side are arranged at a position close to the current path on the side of the above-mentioned current measuring module arranged in the center.

[0022] It can also be that the phase of the current flowing through the above-mentioned current measuring module arranged on the above-mentioned left side lags the phase of the current flowing through the above-mentioned current measuring module arranged in the above-mentioned center by 120°, and the phase of the current flowing through the above-mentioned current measuring module arranged on the above-mentioned right side leads the phase of the current flowing through the above-mentioned current measuring module arranged in the above-mentioned center by 120°.

[0023] In a third aspect of the present invention, a current measuring device is provided. The current measuring device includes three of the above-mentioned arbitrary current measuring modules, and the current measuring modules are arranged in parallel in the above-mentioned second direction. In the above-mentioned second direction, the center position of the two magnetic detection elements of the above-mentioned current measuring module arranged on the left side is arranged at a position close to the current path on the side of the above-mentioned current measuring module arranged in the center, the center position of the two magnetic detection elements of the above-mentioned current measuring module arranged in the center is arranged at a position close to the current path on the side of the above-mentioned current measuring module arranged on the left side, and the center position of the two magnetic detection elements of the above-mentioned current measuring module arranged on the right side is arranged at a position close to the current path on the side of the above-mentioned current measuring module arranged in the center.

[0024] It can also be that the phase of the current flowing through the above-mentioned current measuring module configured on the above-mentioned left side is 120° ahead of the phase of the current flowing through the above-mentioned current measuring module configured in the above-mentioned center, and the phase of the current flowing through the above-mentioned current measuring module configured on the above-mentioned right side is 120° behind the phase of the current flowing through the above-mentioned current measuring module configured in the above-mentioned center.

[0025] In addition, the above summary of the invention does not list all the features of the present invention. In addition, sub-combinations of these feature groups can also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a perspective view showing an example of a schematic structure of the current measuring module 100 in the first embodiment.

[0027] Figure 2 It is a plan view showing an example of a schematic structure of the current measuring module 100 in the first embodiment.

[0028] Figure 3 It is a side cross-sectional view showing an example of a schematic structure of the current measuring module 100 in the first embodiment.

[0029] Figure 4 : is a graph showing the relationship between the position (mm) in the x direction of the magnetic detection element 21 and the magnetic flux density (mT).

[0030] Figure 5: is a graph showing the relationship between the center distance (mm) in the x direction of the two magnetic detection elements 21 and 22 and the detected magnetic flux density (mT).

[0031] Figure 6 : is a graph showing the relationship between the center distance (mm) in the x direction of the two magnetic detection elements 21 and 22 and the detected magnetic flux density (mT).

[0032] Figure 7 It is a plan view showing another example of the schematic structure of the current measuring module 100 in the first embodiment.

[0033] Figure 8 : This is a graph showing the relationship between the widths of the conductor 10 and the two current paths 13 and 14 in the x direction and the rate of change (%) of detected magnetic flux density.

[0034] Fig. 9 : This is a graph showing the relationship between the widths of the conductor 10 and the two current paths 13 and 14 in the x direction and the rate of change (%) of detected magnetic flux density.

[0035] Fig.10 : This is a graph showing the relationship between the widths of the conductor 10 and the two current paths 13 and 14 in the x direction and the rate of change (%) of detected magnetic flux density.

[0036] Fig.11 Graph showing the relationship between the width (mm) of the two current paths 13 and 14 and the conductor 10 in the x direction and the rate of change (%) of magnetic flux density at 100 Hz.

[0037] Fig.12 Graph showing the relationship between the width (mm) of the two current paths 13 and 14 and the conductor 10 in the x direction and the rate of change (%) of magnetic flux density at 100 Hz.

[0038] Fig.13 Graph showing the relationship between the width (mm) of the two current paths 13 and 14 and the conductor 10 in the x direction and the rate of change (%) of magnetic flux density at 100 Hz.

[0039] Fig.14 Graph showing the relationship between the width (mm) of the two current paths 13 and 14 and the conductor 10 in the x direction and the rate of change (%) of magnetic flux density at 100 Hz.

[0040] Fig.15 : is a graph showing the relationship between the z coordinate of one magnetic detection element 21 (or magnetic detection element 22 ) and the magnetic flux density (mT) detected by the magnetic detection element 21 .

[0041] Fig.16 A first example of a method of fixing the magnetic detection unit 20 to the conductor 10 is shown.

[0042] Fig.17 A second example of the method of fixing the magnetic detection unit 20 to the conductor 10 is shown.

[0043] Fig.18 A third example of the method of fixing the magnetic detection unit 20 to the conductor 10 is shown.

[0044] Fig.19 It is a plan view showing an example of a schematic configuration of a current measuring device 200 according to the second embodiment.

[0045] Fig. 20 It is a plan view showing an example of a schematic structure of a current measuring device 300 according to the third embodiment.

[0046] Fig.21 It is a plan view showing an example of a schematic structure of a current measuring device 400 in a comparative example.

[0047] Fig. 22 : is a graph showing the frequency characteristics of the current measuring device 200 in the second embodiment.

[0048] Fig.23 : is a graph showing the frequency characteristics of the current measuring device 200 in the second embodiment.

[0049] Fig.24 : is a graph showing the frequency characteristics of the current measuring device 200 in the second embodiment.

[0050] Fig.25 : is a graph showing the frequency characteristics of the current measuring device 400 in the comparative example.

[0051] Fig.26 : is a graph showing the frequency characteristics of the current measuring device 400 in the comparative example.

[0052] Fig. 27 : is a graph showing the frequency characteristics of the current measuring device 400 in the comparative example.

[0053] Description of symbols

[0054] 10 conductors

[0055] 11, 12 Main body

[0056] 13, 14 Current path

[0057] 15Through holes

[0058] 20 Magnetic detection unit

[0059] 21, 22 Magnetic detection element

[0060] 31~33 Insulation components

[0061] 34 substrate

[0062] 100 Current Measurement Module

[0063] 200, 300, 400 current measuring device DETAILED DESCRIPTION

[0064] Hereinafter, the present invention will be described by way of the embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, the combination of features described in the embodiments is not necessarily all essential to the solution means of the invention.

[0065] [Structure of the first embodiment]

[0066] Figure 1 It is a perspective view showing an example of a schematic structure of the current measuring module 100 in the first embodiment. Figure 2 It is a plan view showing an example of a schematic structure of the current measuring module 100 in the first embodiment. Figure 3 1 is a side cross-sectional view showing an example of the schematic structure of the current measuring module 100 in the first embodiment. Each figure shows an xyz coordinate system. The first direction in the claims is the y direction, the second direction is the x direction, and the third direction is the z direction. Figures 1 to 3 As shown, the current measuring module 100 includes a conductor 10 and a magnetic detection unit 20. The conductor 10 includes two main bodies 11, 12 and two current paths 13, 14, and a through hole 15 is formed by the two main bodies 11, 12 and the two current paths 13, 14. In addition, the conductor 10 is also called a bus bar. The magnetic detection unit 20 includes two magnetic detection elements 21, 22.

[0067] like Figures 1 to 3 As shown, the two main bodies 11 and 12 are arranged side by side in the y direction. The two current paths 13 and 14 are arranged between the two main bodies 11 and 12 and extend in parallel to each other, connecting the two main bodies 11 and 12. A through hole 15 is arranged between the two current paths 13 and 14. The measured current flows in the same direction to each of the two current paths 13 and 14. In the present embodiment, the two current paths 13 and 14 are conductors having a rectangular cross-sectional shape and extending in a straight line. In addition, the cross-sectional shape of the two current paths 13 and 14 can be any shape such as a circle or an ellipse.

[0068] like Figure 2As shown, the two current paths 13 and 14 have the same width in the x direction. The width of the two current paths 13 and 14 in the x direction is, for example, 3 mm. The width of the conductor 10 in the x direction is, for example, 18 mm. That is, the width of the through hole in the x direction is, for example, 12 mm. When the two current paths 13 and 14 become thicker, the influence of the skin effect becomes greater, so the width of the two current paths 13 and 14 in the x direction is preferably 4 mm or less. In addition, the thickness (width in the z direction) of the conductor 10 is preferably 4 mm or less.

[0069] like Figure 2 As shown in FIG. 1 , the two magnetic detection elements 21 and 22 are arranged side by side in the x direction. The two magnetic detection elements 21 and 22 are arranged at positions close to either of the two current paths 13 and 14 in the x direction. Figure 2 In the example shown, the two magnetic detection elements 21 and 22 are arranged at positions close to the current path 14 and far from the current path 13. Figure 2 In this configuration, the intensity of the magnetic field detected from the current path 14 closer to the current path 14 increases, and the S / N ratio of the detected signal can be improved. Alternatively, the two magnetic detection elements 21 and 22 may be arranged close to the current path 13 and far from the current path 14.

[0070] The two magnetic detection elements 21 and 22 respectively detect the strength of the magnetic field generated on each magnetic sensing surface due to the measured current flowing to the two current paths 13 and 14 respectively along the y direction, and output a detection signal corresponding to the difference in the detection strength detected by the two magnetic detection elements 21 and 22. That is, in the present embodiment, the detection signal output by the combination of the two magnetic detection elements 21 and 22 is a differential output. The two magnetic detection elements 21 and 22 are respectively configured so that the magnetic field generated by the measured current flowing to the two current paths 13 and 14 respectively along the same direction passes through the magnetic sensing surface. The two magnetic detection elements 21 and 22 are configured between the two current paths 13 and 14 in such a way that the orientations of the magnetic sensing surfaces are consistent with each other. In the present embodiment, the orientation of the magnetic sensing surface, that is, the normal direction of the surface is the z direction.

[0071] like Figure 2 As shown in FIG. 1 , when viewed from the z direction, the two magnetic detection elements 21 and 22 are arranged in the through hole 15. Figure 3 As shown in FIG. 1 , the magnetic detection unit 20 is arranged so that the positions of the magnetic sensing surfaces of the two magnetic detection elements 21 and 22 in the z direction are 1 mm from the upper surface of the conductor 10. The magnetic detection unit 20 is fixed to the conductor 10 by an insulating member or the like (not shown). Figures 15 to 17 Describe it in the description part.

[0072] As the two magnetic detection elements 21 and 22, magnetoelectric conversion elements can be used. As the magnetoelectric conversion element, for example, a Hall element that can obtain a detection signal proportional to the magnitude of the magnetic flux density can be used. In addition, as the magnetoelectric conversion element, in addition to the Hall element, a magnetoresistive element, a magnetoimpedance element, etc. can also be used. Furthermore, as long as it is a magnetic sensor IC composed of these magnetoelectric conversion elements and an IC processing circuit, and the detection signal is uniquely determined relative to the applied magnetic flux density, it can be used as the two magnetic detection elements 21 and 22. The shapes and sizes of the two magnetic detection elements 21 and 22 may also be different.

[0073] Figure 4 : is a graph showing the relationship between the position (mm) of the magnetic detection element 21 in the x direction and the magnetic flux density (mT) in the z direction. Figure 4 The graph shows changes in magnetic flux density detected when one magnetic detection element 21 (or magnetic detection element 22 ) is moved in the through hole 15 in the x direction. Figure 4 The horizontal axis represents the position (mm) in the x direction of the center of the magnetic detection element 21, and the vertical axis represents the magnetic flux density (mT) detected by the magnetic detection element 21. Figure 4 In FIG. 1 , the area where the horizontal axis has a positive value indicates that the magnetic detection element 21 is close to the current path 14 , and the area where the horizontal axis has a negative value indicates that the magnetic detection element 21 is close to the current path 13 . Figure 4 In FIG. 1 , the point where the horizontal axis is 0 mm indicates that the center of the magnetic detection element 21 in the x direction coincides with the center of the through hole 15 in the x direction.

[0074] like Figure 4 As shown, the closer the magnetic detection element 21 is to the current path 13, the stronger the magnetic field received from the current path 13, and therefore the greater the detected magnetic flux density. In addition, the closer the magnetic detection element 21 is to the current path 14, the stronger the magnetic field in the opposite direction received from the current path 14, and therefore the smaller the detected magnetic flux density. Furthermore, when the magnetic detection element 21 is arranged at the center of the current paths 13 and 14, the magnetic field received from the current path 13 and the magnetic field received from the current path 14 cancel each other out, and the detected magnetic flux density is zero. In addition, if the magnetic detection element 21 is placed too close to the current path 13, the z-direction component of the magnetic field from the current path 13 decreases, and therefore the detected magnetic flux density decreases.

[0075] Figure 5 as well as Figure 6 It is a graph showing the relationship between the center coordinates (mm) of each of the center distances (mm) in the x direction of the two magnetic detection elements 21 and 22 and the detected magnetic flux density (mT), where the center coordinates are the coordinates of the centers of the two magnetic detection elements 21 and 22 in the x direction. Figure 5The horizontal axis of represents the coordinates of the centers of the two magnetic detection elements 21 and 22 in the x direction, that is, the center coordinates (mm), with the center of the through hole 15 as a reference (x=0). Figure 5 The vertical axis represents the magnetic flux density (mT) detected by the two magnetic detection elements 21 and 22 through differential output. Figure 6 The horizontal axis of represents the center coordinates (mm) of the two magnetic detection elements 21 and 22 in the x direction, with the center of the through hole 15 as a reference (x=0). Figure 6 The vertical axis represents the ratio (%) of the output change of the magnetic flux density detected by the two magnetic detection elements 21 and 22 compared to the case where the center coordinates of the two magnetic detection elements 21 and 22 in the x direction are zero.

[0076] Figure 5 and Figure 6 The points represented by circles show that the center distance between the two magnetic detection elements 21 and 22 in the x direction is 1 mm, the points represented by squares show that the center distance between the two magnetic detection elements 21 and 22 in the x coordinates is 2 mm, the points represented by diamonds show that the center distance between the two magnetic detection elements 21 and 22 in the x coordinates is 3 mm, and the points represented by triangles show that the center distance between the two magnetic detection elements 21 and 22 in the x direction is 4 mm. Here, the center distance between the two magnetic detection elements 21 and 22 in the x direction refers to the distance between the center of the magnetic detection element 21 and the center of the magnetic detection element 22 in the x direction. Figure 3 It is represented by "C".

[0077] like Figure 5 As shown in FIG. 1 , when the center distance is 4 mm, a magnetic flux density of approximately 6 mT or more is detected, but when the center distance is 1 mm, only a magnetic flux density of approximately 2 mT or less is detected. That is, the larger the center distance in the x direction between the two magnetic detection elements 21 and 22, the larger the magnetic flux density detected by the differential output. In addition, as Figure 6 As shown, the more the x-coordinates of the two magnetic detection elements 21 and 22 deviate from the center, the greater the rate of change of the output ratio. From the perspective of the S / N ratio, it is preferred that the detected magnetic flux density is large. Therefore, the larger the center distance in the x-direction of the two magnetic detection elements 21 and 22, the better, for example, it can be more than 2 mm. In other words, the center distance in the x-direction of the two magnetic detection elements 21 and 22 is preferably more than 10%, more than 15%, or more than 25% relative to the width of the through hole 15 in the x-direction.

[0078] Figure 7 1 is a top view showing another example of the schematic structure of the current measuring module 100 in the first embodiment. In order to ensure the center distance between the two magnetic detection elements 21 and 22 in the x direction and improve the S / N ratio, for example, Figure 7As shown, the two magnetic detection elements 21 and 22 may be arranged relative to the center of the through hole 15. That is, the two magnetic detection elements 21 and 22 may be arranged in such a manner that they are located on opposite sides of the center line L of the through hole 15 in the x direction. In addition, when current flows to the conductor, the magnetic fields received from the two current paths cancel each other, and the two magnetic detection elements 21 and 22 may be arranged relative to each other across a region where the magnetic flux density in the z direction detected is zero.

[0079] Alternatively, the center distance between the two magnetic detection elements 21 and 22 in the x direction may be greater than the magnetic detection element on the first current path side of the two magnetic detection elements 21 and 22 that is closer to the center position between the two magnetic detection elements ( Figure 3 The center position in the x direction of the magnetic detection element 22 in the middle of the magnetic detection element 22 is closer to the center position between the two magnetic detection elements. Figure 3 The distance between the ends of the current path 14). That is, Figure 3 It can also be C>D.

[0080] Figures 8 to 10 It is a graph showing the relationship between the center coordinates (mm) of each width in the x direction of the conductor 10 and the two current paths 13 and 14 and the change rate (%) of the detected magnetic flux density. The center coordinates (mm) are the coordinates of the center of the two magnetic detection elements 21 and 22 in the x direction. Figures 8 to 10 The horizontal axis in represents the center positions of the two magnetic detection elements 21 and 22 in the x direction (ie, the center positions of the magnetic detection elements 21 and 22 in the x direction) (mm), with the center of the through hole 15 as a reference (x=0). Figures 8 to 10 The vertical axis in φ represents the variation rate (%) of the magnetic flux density detected by the two magnetic detection elements 21 and 22 with respect to 100 Hz. Figures 8 to 10 The white circle in the figure represents the rate of change of the magnetic flux density at 1000 Hz, and the square represents the rate of change of the magnetic flux density at 2000 Hz. Figure 8 There are areas where the rate of change exceeds 0%, which are not shown in the chart.

[0081] Figure 8 The case 1 in which the width of the conductor 10 in the x direction is 18 mm and the width of the two current paths 13 and 14 in the x direction is 3 mm is shown. Fig. 9 The case 2 in which the width of the conductor 10 in the x direction is 24 mm and the width of the two current paths 13 and 14 in the x direction is 4 mm is shown. Fig.10 The case 3 in which the width of the conductor 10 in the x direction is 30 mm and the width of the two current paths 13 and 14 in the x direction is 4 mm is shown. Figures 8 to 10 In the figure, the center distance between the two magnetic detection elements 21 and 22 in the x direction is 3 mm, and the distance between the positions of the magnetic sensing surfaces of the two magnetic detection elements 21 and 22 in the z direction and the upper surface of the conductor 10 is 1 mm.

[0082] Here, the area with a change rate of the magnetic flux density at 2000 Hz within -3% is the largest, and it can be said that the change of the detection value caused by the frequency is small, which is preferable from the viewpoint of frequency characteristics. Fig.10 The case 3 shown. Therefore, among the cases 1 to 3, the case 3 in which the width of the conductor 10 in the x direction is 30 mm and the width of the two current paths 13 and 14 in the x direction is 4 mm is the most preferable.

[0083] exist Figure 8 In the figure, both magnetic detection elements 21 and 22 are separated from the inner ends of the two current paths 13 and 14 by more than 1 mm, and the coordinates are inward of ±3 mm of the horizontal axis. Fig. 9 In the figure, both magnetic detection elements 21 and 22 are separated from the inner ends of the two current paths 13 and 14 by more than 1 mm, and the coordinates are inward of ±5 mm on the horizontal axis. Fig.10 In the figure, both magnetic detection elements 21 and 22 are separated from the inner ends of the two current paths 13 and 14 by more than 1 mm, and the coordinates are located inward of ±8 mm on the horizontal axis.

[0084] Here, in Figure 8 The area outside the horizontal axis ±3mm, Fig. 9 The area outside the horizontal axis ±5mm, Fig.10 The magnetic flux density varies greatly in the area outside ±8 mm of the horizontal axis. This is because when the two magnetic detection elements 21 and 22 are too close to either of the two current paths 13 and 14, they are easily affected by the skin effect, and the frequency-induced variation rate becomes larger. Therefore, from the perspective of frequency characteristics, it is preferred that either of the two magnetic detection elements 21 and 22 is arranged at least 1 mm away from the inner end of the two current paths 13 and 14 in the x direction.

[0085] Figures 11 to 14 Graph showing the relationship between the width (mm) of the two current paths 13 and 14 and the conductor 10 in the x direction and the rate of change (%) of magnetic flux density at 100 Hz. Figures 11 to 14 The horizontal axis represents the center positions of the two magnetic detection elements 21 and 22 in the x direction (ie, the center positions of the magnetic detection elements 21 and 22 in the x direction) (mm), with the center of the through hole 15 as a reference (x=0). Figures 11 to 14The vertical axis represents the variation rate (%) of the magnetic flux density detected by the two magnetic detection elements 21 and 22 with respect to 100 Hz. Figures 11 to 14 The white circles in the figure indicate that the width of the two current paths 13 and 14 in the x-direction is 3 mm, the squares indicate that the width of the two current paths 13 and 14 in the x-direction is 4 mm, and the diamonds indicate that the width of the two current paths 13 and 14 in the x-direction is 5 mm. Figures 11 to 14 The right side of shows the value obtained by dividing the widths of the two current paths 13 , 14 in the x direction by the width of the conductor 10 in the x direction.

[0086] Fig.11 The case 4 in which the width of the conductor 10 in the x direction is 18 mm is shown. Fig.12 The case 5 in which the width of the conductor 10 in the x direction is 20 mm is shown. Fig.13 The case 6 in which the width of the conductor 10 in the x direction is 24 mm is shown. Fig.14 The case 7 in which the width of the conductor 10 in the x direction is 30 mm is shown. Figures 11 to 14 In the embodiment, the frequency of the current flowing to the conductor 10 is set to 2000 Hz, the center distance between the two magnetic detection elements 21 and 22 in the x direction is set to 3 mm, and the distance between the positions of the magnetic sensing surfaces of the two magnetic detection elements 21 and 22 in the z direction and the upper surface of the conductor 10 in the z direction is set to 1 mm. Figures 11 to 14 The more regions in which the rate of change of the magnetic flux density at 2000 Hz is within -3%, the more preferable it is from the viewpoint of frequency characteristics.

[0087] like Fig.11 As shown in Figure 4, in the case where the width of the conductor 10 in the x direction is 18 mm, when the width of the two current paths 13 and 14 in the x direction is 3 mm, the change rate of the magnetic flux density is around -3%, which is a preferred value. However, when the width of the two current paths 13 and 14 in the x direction is 4 mm or 5 mm, the change rate exceeds -4%, which is not preferred. Fig.12 As shown, in case 5 where the width of the conductor 10 in the x direction is 20 mm, when the width of the two current paths 13 and 14 in the x direction is 4 mm, the variation rate is roughly within -3%, which is a preferred value, but when the width of the two current paths 13 and 14 in the x direction is 5 mm, the variation rate is around -4%, which is not preferred.

[0088] like Fig.13As shown in Figure 6, in the case where the width of the conductor 10 in the x direction is 24 mm, when the width of the two current paths 13 and 14 in the x direction is 4 mm, the variation rate is around -3%, which is a preferred value. However, when the width of the two current paths 13 and 14 in the x direction is 5 mm, the variation rate exceeds -3%, which is not preferred. Fig.14 As shown, in case 7 where the width of the conductor 10 in the x-direction is 30 mm, when the width of the two current paths 13 and 14 in the x-direction is 4 mm, the variation rate is within -3%, which is a preferred value, and when the width of the two current paths 13 and 14 in the x-direction is 5 mm, the variation rate is near -3%, which is also a preferred value.

[0089] Based on the above, as the combination of the width of the conductor 10 and the two current paths 13 and 14, the combination of 18 mm and 3 mm in case 4, 20 mm and 4 mm in case 5, 24 mm and 4 mm in case 6, 30 mm and 4 mm in case 7, and 30 mm and 5 mm are preferred. Therefore, it can be seen that when the value obtained by dividing the width of the two current paths 13 and 14 in the x direction by the width of the conductor 10 in the x direction is 20% or less, the variation rate becomes a desired value.

[0090] If the current paths 13 and 14 are thick, the influence of the skin effect becomes larger, so the frequency characteristics deteriorate. Therefore, from the perspective of frequency characteristics, it is preferred that the current paths 13 and 14 are thinner. On the other hand, if the width of the conductor 10 is increased and the width of the through hole 15 is increased, the two magnetic detection elements 21 and 22 can be moved away from the current paths 13 and 14, and the influence of the skin effect becomes relatively smaller, so a place with good frequency characteristics can be selected. Based on the above, it is preferred to reduce the width of the current paths 13 and 14 or increase the entire width of the conductor 10 in terms of frequency characteristics so that the ratio of the width of the current paths 13 and 14 to the width of the conductor 10 is less than 20%.

[0091] Fig.15 : is a graph showing the relationship between the z coordinate of one magnetic detection element 21 (or magnetic detection element 22 ) and the magnetic flux density (mT) detected by the magnetic detection element 21 . Fig.15 The horizontal axis of represents the position of the magnetic sensing surface of the magnetic detection element 21 in the z direction, and is represented with respect to the upper surface of the conductor 10 as a reference (z=0). Fig.15 The vertical axis represents the magnetic flux density (mT) detected by the magnetic detection element 21. Fig.15 , the maximum magnetic field when a current of ±1000 A and 2000 Hz flows is shown. The magnetic detection element 21 was arranged 3.5 mm inward from the current path 13 in the x direction, and the thickness of the conductor 10 in the z direction was set to 2 mm for simulation.

[0092] like Fig.15 As shown, as the z coordinate of the magnetic detection element 21 moves away from the upper surface of the conductor 10, the detected magnetic flux density decreases. If the detected magnetic flux density is lower than 1mT, the detection accuracy of the current measurement module 100 is insufficient. Therefore, the magnetic detection element 21 is preferably configured in such a way that the position of the magnetic sensing surface in the z direction is within 4mm from the upper surface of the conductor 10. The same is true for the magnetic detection element 22. In addition, in the case where the two magnetic detection elements 21 and 22 are arranged on the -z direction side of the conductor 10, it is also preferably configured to be within 4mm from the lower surface of the conductor 10.

[0093] Fig.16 FIG. 1 shows a first example of a method for fixing the magnetic detection unit 20 to the conductor 10. Fig.16 As shown, in the first example, the magnetic detector 20 is fixed to the conductor 10 via an insulating member 31 made of resin or the like. The insulating member 31 is arranged to cover the upper surface of the conductor 10 and fill the through hole 15. The magnetic detector 20 is fixed to the upper part of the insulating member 31.

[0094] Fig.17 FIG. 2 shows a second example of a method for fixing the magnetic detection unit 20 to the conductor 10. Fig.17 As shown, in the second example, the magnetic detector 20 is fixed to the conductor 10 via an insulating member 32 made of resin or the like. The insulating member 32 is arranged to cover the lower surface of the conductor 10 and to fill a part of the through hole 15. The magnetic detector 20 is fixed to the upper part of the insulating member 32.

[0095] Fig.18 A third example of a method for fixing the magnetic detection unit 20 to the conductor 10 is shown. Fig.18 As shown, in the third example, the magnetic detection unit 20 is fixed to the conductor 10 via an insulating member 33 made of resin or the like and a substrate 34. The insulating member 33 is arranged in a manner covering the lower surface and the side surface of the conductor 10. The substrate 34 connected to the insulating member 33 is arranged on the upper part of the conductor 10, and the magnetic detection unit 20 is fixed to the lower part of the substrate 34.

[0096] By utilizing Figures 16 to 18 By fixing the magnetic detector 20 to the conductor 10 in this way, it is possible to prevent the magnetic detector 20 from being displaced in the z direction, thereby improving the measurement accuracy of the current measurement module 100. In addition, the current measurement module 100 can be made small and simple in structure.

[0097] [Effects of the First Embodiment]

[0098] According to the current measuring module 100 of the first embodiment, the two magnetic detection elements 21 and 22 are arranged in the x direction close to one of the two current paths 13 and 14. This ensures that the magnetic flux density detected from the closer current path is sufficient, and the S / N ratio of the current measuring module 100 can be improved.

[0099] According to the current measuring module 100 of the first embodiment, the center distance between the two magnetic detection elements 21 and 22 in the x direction is 2 mm or more. This can increase the magnetic flux density detected by differential output and improve the S / N ratio of the current measuring module 100 .

[0100] According to the current measuring module 100 of the first embodiment, the width of each of the two current paths 13 and 14 in the x direction is 20% or less of the width of the conductor 10 in the x direction. This can improve the frequency characteristics of the current measuring module 100.

[0101] According to the current measuring module 100 of the first embodiment, the two magnetic detection elements 21 and 22 are arranged so that the positions of the magnetic sensing surfaces in the z direction are within 4 mm from the upper surface of the conductor 10. This can increase the magnetic flux density detected from the two current paths 13 and 14, and improve the S / N ratio of the current measuring module 100.

[0102] According to the current measuring module 100 of the first embodiment, the two magnetic detection elements 21 and 22 are arranged to be separated in the x direction by 1 mm or more from the inner ends of the two current paths 13 and 14. This can improve the frequency characteristics of the current measuring module 100.

[0103] [Structure of the Second Embodiment]

[0104] Fig.19 1 is a top view showing an example of a schematic structure of a current measuring device 200 in the second embodiment. In the following description of the second embodiment, the same reference numerals are given to the parts common to the current measuring module 100 in the first embodiment, and the description thereof is omitted. Fig.19 As shown, the current measuring device 200 in the second embodiment includes three current measuring modules 100 in the first embodiment, and the three current measuring modules 100 are arranged in parallel in the x direction.

[0105] The phase of the current flowing through the current measuring module 100 arranged on the left side lags the phase of the current flowing through the current measuring module 100 arranged in the center by 120°, and the phase of the current flowing through the current measuring module 100 arranged on the right side leads the phase of the current flowing through the current measuring module 100 arranged in the center by 120°. The three current measuring modules 100 correspond to the U phase, V phase, and W phase of the three-phase AC, respectively.

[0106] The center positions in the x direction of the two magnetic detection elements 21 and 22 of the current measuring module 100 arranged on the left are arranged at a position close to the current path 14 on the side of the current measuring module 100 arranged in the center. The center positions in the x direction of the two magnetic detection elements 21 and 22 of the current measuring module 100 arranged in the center are arranged at a position close to the current path 14 on the side of the current measuring module 100 arranged on the right. The center positions in the x direction of the two magnetic detection elements 21 and 22 of the current measuring module 100 arranged on the right are arranged at a position close to the current path 13 on the side of the current measuring module 100 arranged in the center.

[0107] [Structure of the Third Embodiment]

[0108] Fig. 20 1 is a top view showing an example of a schematic structure of a current measuring device 300 in the third embodiment. In the following description of the third embodiment, the same reference numerals are given to the parts common to the current measuring module 100 in the first embodiment, and the description thereof is omitted. Fig. 20 As shown, the current measuring device 300 in the third embodiment includes three current measuring modules 100 in the first embodiment, and the three current measuring modules 100 are arranged in parallel in the x direction.

[0109] The phase of the current flowing through the current measuring module 100 arranged on the left side is 120° ahead of the phase of the current flowing through the current measuring module 100 arranged in the center, and the phase of the current flowing through the current measuring module 100 arranged on the right side is 120° behind the phase of the current flowing through the current measuring module 100 arranged in the center. The three current measuring modules 100 correspond to the U phase, V phase, and W phase of the three-phase AC, respectively.

[0110] The center positions in the x direction of the two magnetic detection elements 21 and 22 of the current measuring module 100 arranged on the left are arranged at a position close to the current path 14 on the side of the current measuring module 100 arranged in the center. The center positions in the x direction of the two magnetic detection elements 21 and 22 of the current measuring module 100 arranged in the center are arranged at a position close to the current path 13 on the side of the current measuring module 100 arranged on the left. The center positions in the x direction of the two magnetic detection elements 21 and 22 of the current measuring module 100 arranged on the right are arranged at a position close to the current path 13 on the side of the current measuring module 100 arranged in the center.

[0111] [Structure of Comparative Example]

[0112] Fig.211 is a top view showing an example of a schematic structure of a current measuring device 400 in a comparative example. In the following description of the comparative example, the same reference numerals are given to the parts common to the current measuring module 100 in the first embodiment, and the description thereof is omitted. Fig.21 As shown, the current measuring device 400 in the comparative example includes three current measuring modules 100 in the first embodiment, and the three current measuring modules 100 are arranged in parallel in the x direction.

[0113] The phase of the current flowing through the current measuring module 100 arranged on the left side is 120° ahead of the phase of the current flowing through the current measuring module 100 arranged in the center, and the phase of the current flowing through the current measuring module 100 arranged on the right side is 120° behind the phase of the current flowing through the current measuring module 100 arranged in the center. The three current measuring modules 100 correspond to the U phase, V phase, and W phase of the three-phase AC, respectively.

[0114] The two magnetic detection elements 21 and 22 of the three current measuring modules 100 are arranged so that the center positions of the two magnetic detection elements 21 and 22 in the x direction coincide with the center of the through hole 15. That is, in the comparative example, the two magnetic detection elements 21 and 22 are not arranged close to any of the current paths 13 and 14.

[0115] Figure 22 to Figure 27 : is a graph showing a comparison of frequency characteristics between the current measuring device 200 in the second embodiment and the current measuring device 400 in the comparative example. Figure 22 to Figure 24 The frequency characteristics of the current measuring modules 100 of the U phase, V phase, and W phase of the current measuring device 200 in the second embodiment are shown respectively. Figure 25 to Figure 27 The frequency characteristics of the current measuring modules 100 of the U-phase, V-phase, and W-phase of the current measuring device 400 in the comparative example are shown respectively. Figure 22 to Figure 27 The horizontal axis represents the frequency (Hz) of the current flowing through the current measuring module 100, and the vertical axis represents the rate of change (%) of magnetic flux density with respect to 100 Hz.

[0116] like Fig. 22 As shown in FIG. 1 , in the current measuring module 100 of the U phase of the current measuring device 200, the magnetic flux density hardly changes at 1000 Hz, and falls within a range of about -3% decrease at 10000 Hz. Fig.25 As shown, in the current measuring module 100 of the U phase of the current measuring device 400, the magnetic flux density decreases to about -1.5% at 1000 Hz and to about -5% at 10000 Hz. Therefore, it can be seen that in the current measuring module 100 of the U phase, the frequency characteristics of the current measuring device 200 in the second embodiment are better than the frequency characteristics of the current measuring device 400 in the comparative example.

[0117] like Fig.23 As shown in FIG. 1 , in the V-phase current measuring module 100 of the current measuring device 200 , the magnetic flux density hardly changes at 1000 Hz, and falls within a range of about -5% decrease at 10000 Hz. Fig.26 As shown, in the V-phase current measuring module 100 of the current measuring device 400, the magnetic flux density decreases to approximately -1.5% at 1000 Hz and decreases to approximately -5% at 10000 Hz. Therefore, it can be seen that in the V-phase current measuring module 100, the frequency characteristics of the current measuring device 200 in the second embodiment are superior to the frequency characteristics of the current measuring device 400 in the comparative example.

[0118] like Fig.24 As shown in FIG. 1 , in the current measuring module 100 of the W phase of the current measuring device 200, the magnetic flux density hardly changes at 1000 Hz, and falls within a range of about -1% decrease at 10000 Hz. Fig. 27 As shown, in the current measuring module 100 of the W phase of the current measuring device 400, the magnetic flux density decreases to about -1.5% at 1000 Hz and decreases to about -4.5% at 10000 Hz. Therefore, it can be seen that in the current measuring module 100 of the W phase, the frequency characteristics of the current measuring device 200 in the second embodiment are better than the frequency characteristics of the current measuring device 400 in the comparative example.

[0119] As can be seen from the above, the frequency characteristics of the current measuring device 200 in the second embodiment are superior to those of the current measuring device 400 in the comparative example in terms of the U phase, the V phase, and the W phase, and therefore the configuration of the current measuring device 200 in the second embodiment is preferred. In addition, the current measuring device 300 in the third embodiment is also superior to the current measuring device 400 in the comparative example in terms of frequency characteristics, similarly to the current measuring device 200 in the second embodiment.

[0120] [Effects of the Second and Third Embodiments]

[0121] According to the current measuring device 200 in the second embodiment and the current measuring device 300 in the third embodiment, the three current measuring modules 100 are arranged in parallel in the x direction, and the two magnetic detection elements 21 and 22 of the three current measuring modules 100 are arranged at positions close to any current path 13 and 14. Thus, the frequency characteristics of the current measuring devices 200 and 300 can be improved.

[0122] The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. According to the description of the claims, the method to which such changes or improvements are made is also included in the technical scope of the present invention.

[0123] It should be noted that the execution order of each process such as actions, steps, steps and stages in the device, system, program and method shown in the claims, specifications and drawings can be implemented in any order unless it is specifically stated as "before", "before", etc., and as long as the output of the previous process is not used in the subsequent process. Even if the action flow in the claims, specifications and drawings is described using "first", "next", etc. for convenience, it does not mean that it must be implemented in this order.

Claims

1. A current measurement module, wherein: The current measurement module comprises: A conductor having two main bodies and two current paths, wherein the two main bodies are arranged in parallel in a first direction, and the two current paths are arranged in parallel in a second direction orthogonal to the first direction with a through hole therebetween and connect the two main bodies; and two magnetic detection elements, each having a magnetic sensing surface and arranged in parallel in the second direction, wherein the magnetic sensing surface detects a component in a third direction orthogonal to the first direction and the second direction in the magnetic field generated by the current flowing through the two current paths, When viewed from the third direction, the two magnetic detection elements are arranged inside the through hole. In the second direction, the center position between the two magnetic detection elements is close to either of the two current paths.

2. The current measuring module according to claim 1, wherein: The center distance between the two magnetic detection elements in the second direction is 2 mm or more.

3. The current measuring module according to claim 1, wherein: A distance between the two magnetic detection elements in the second direction is equal to or greater than 15% of a width of the through hole in the second direction.

4. The current measuring module according to claim 1, wherein: A width of each of the two current paths in the second direction is less than or equal to 20% of a width of the conductor in the second direction.

5. The current measuring module according to claim 1, wherein: The width of each of the two current paths in the second direction is 4 mm or less.

6. The current measurement module according to claim 1, wherein: The widths of the two current paths in the second direction are the same.

7. The current measuring module according to claim 1, wherein: The positions of the magnetic sensing surfaces of the two magnetic detection elements in the third direction are within a range of 4 mm from the upper surfaces of the two current paths.

8. The current measuring module according to claim 1, wherein: The width of the conductor in the third direction is 4 mm or less.

9. The current measuring module according to claim 1, wherein: a current path closer to the center position between the two magnetic detection elements in the second direction as a first current path, The two magnetic detection elements are each arranged to be separated by 1 mm or more from the inner end of the first current path.

10. The current measuring module according to claim 1, wherein: a current path closer to the center position between the two magnetic detection elements in the second direction as a first current path, The center distance between the two magnetic detection elements is larger than the distance between the center position of the magnetic detection element on the first current path side of the two magnetic detection elements and the end of the first current path.

11. The current measuring module according to claim 1, wherein: In the second direction, the two magnetic detection elements are arranged to be opposed to each other with respect to the center of the through hole.

12. The current measuring module according to claim 1, wherein: In the second direction, when current flows through the conductor, magnetic fields received from the two current paths cancel each other, and the two magnetic detection elements are arranged to face each other across a region where the magnetic flux density detected in the third direction is zero.

13. The current measuring module according to claim 1, wherein: The two magnetic detection elements are Hall elements.

14. The current measuring module according to claim 1, wherein: The current measuring module further includes an insulating member that fixes the two magnetic detection elements to the conductor.

15. The current measuring module according to claim 1, wherein: The current measuring module further includes a substrate that fixes the two magnetic detection elements to the conductor.

16. A current measuring device, wherein: The current measuring device comprises three current measuring modules according to claim 1, wherein the three current measuring modules are arranged in parallel in the second direction. In the second direction, The center position of the two magnetic detection elements of the current measuring module arranged on the left side is arranged at a position close to the current path on the side of the current measuring module arranged in the center. The center position of the two magnetic detection elements of the current measuring module arranged in the center is arranged at a position close to the current path on the side of the current measuring module arranged on the right side. The center position of the two magnetic detection elements of the current measuring module arranged on the right side is arranged at a position close to the current path on the side of the current measuring module arranged in the center.

17. The current measuring device according to claim 16, wherein: The phase of the current flowing through the current measuring module arranged on the left side lags the phase of the current flowing through the current measuring module arranged in the center by 120°, and the phase of the current flowing through the current measuring module arranged on the right side leads the phase of the current flowing through the current measuring module arranged in the center by 120°.

18. A current measuring device, wherein: The current measuring device comprises three current measuring modules according to claim 1, wherein the three current measuring modules are arranged in parallel in the second direction. In the second direction, The center position of the two magnetic detection elements of the current measuring module arranged on the left side is arranged at a position close to the current path on the side of the current measuring module arranged in the center. The center position of the two magnetic detection elements of the current measuring module arranged in the center is arranged at a position close to the current path on the side of the current measuring module arranged on the left side. The center position of the two magnetic detection elements of the current measuring module arranged on the right side is arranged at a position close to the current path on the side of the current measuring module arranged in the center.

19. The current measuring device according to claim 18, wherein: The phase of the current flowing through the current measuring module arranged on the left side is 120° ahead of the phase of the current flowing through the current measuring module arranged in the center, and the phase of the current flowing through the current measuring module arranged on the right side is 120° behind the phase of the current flowing through the current measuring module arranged in the center.

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