Current measuring module and current measuring device

Abstract

SOLUTION: A current measuring module comprises: an electric conductor including two body parts arranged side by side in a first direction, and two current paths which are arranged side by side by interposing an open hole in a second direction orthogonal to the first direction, and which connect the two body parts; and two magnetic detection elements which each comprise a magneto-sensitive plane for detecting a component in a third direction orthogonal to the first direction and the second direction, within a magnetic field generated by current flowing in the two current paths, and which are arranged side by side in the second direction. When viewed from a third direction, the two magnetic detection elements are disposed inside the open hole and a center position of each of the two magnetic detection elements is closer to one of the two current paths in the second direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a current measurement module and a current measurement device. [Background technology]

[0002] Patent Document 1 discloses a "sensing system for non-contact sensing of current flowing through a conductor." [Prior art document] [Patent documents] [Patent Document 1] U.S. Patent Application Publication No. 2023 / 0204632 Summary of the Invention

[0003] In a first aspect of the present invention, there is provided a current measurement module, comprising: a conductor having two main body parts arranged side by side in a first direction, two current paths arranged side by side across a through hole in a second direction perpendicular to the first direction and connecting the two main body parts, and two magnetic detection elements arranged side by side in the second direction, each having a magnetic sensing surface for detecting a component in a third direction perpendicular to the first direction and the second direction of a magnetic field generated by a current flowing through the two current paths, the magnetic detection elements being arranged inside the through hole when viewed from the third direction, and a center position between the two magnetic detection elements being close to one of the two current paths in the second direction.

[0004] The center distance between the two magnetic sensing elements in the second direction may be 2 mm or more.

[0005] The distance between the two magnetic detection elements in the second direction may be 15% or more of the width of the through hole in the second direction.

[0006] The width of each of the two current paths in the second direction may be 20% or less of the width of the conductor in the second direction.

[0007] The width of each of the two current paths in the second direction may be 4 mm or less.

[0008] The two current paths may have the same width in the second direction.

[0009] The positions of the magnetic sensing 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.

[0010] The conductor may have a width in the third direction of 4 mm or less.

[0011] In the second direction, the current path closer to the center position between the two magnetic detection elements is defined as a first current path, and both of the two magnetic detection elements may be 1 mm or more away from the inner end of the first current path.

[0012] In the second direction, the current path closer to a center position between the two magnetic detection elements may be a first current path, and the center distance between the two magnetic detection elements may be 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.

[0013] In the second direction, the two magnetic detection elements may be disposed opposite each other with respect to the center of the through hole.

[0014] The two magnetic detection elements may be arranged facing each other across a region in which, when a current flows through the conductor in the second direction, the magnetic fields received from the two current paths cancel each other out, and the detected magnetic flux density in the third direction is zero.

[0015] The two magnetic detection elements may be Hall elements.

[0016] The sensor may further include an insulating member that fixes the two magnetic sensing elements to the conductor.

[0017] The sensor may further include a substrate for fixing the two magnetic sensing elements to the conductor.

[0018] In a second aspect of the present invention, there is provided a current measuring device, comprising three of any of the current measuring modules arranged side by side in the second direction, in which, in the second direction, the central positions of the two magnetic detection elements of the current measuring module arranged on the left side are arranged close to the current path on the side of the current measuring module arranged in the center, the central positions of the two magnetic detection elements of the current measuring module arranged on the center are arranged close to the current path on the side of the current measuring module arranged on the right side, and the central positions of the two magnetic detection elements of the current measuring module arranged on the right side are arranged close to the current path on the side of the current measuring module arranged in the center.

[0019] The phase of the current flowing through the current measurement module located on the left side may be delayed by 120° from the phase of the current flowing through the current measurement module located in the center, and the phase of the current flowing through the current measurement module located on the right side may be advanced by 120° from the phase of the current flowing through the current measurement module located in the center.

[0020] In a third aspect of the present invention, there is provided a current measuring device, comprising three of any of the current measuring modules arranged side by side in the second direction, in which, in the second direction, the center positions of the two magnetic detection elements of the current measuring module arranged on the left side are arranged close to the current path on the side of the current measuring module arranged in the center, the center positions of the two magnetic detection elements of the current measuring module arranged in the center are arranged close to the current path on the side of the current measuring module arranged on the left side, and the center positions of the two magnetic detection elements of the current measuring module arranged on the right side are arranged close to the current path on the side of the current measuring module arranged in the center.

[0021] The phase of the current flowing through the current measurement module located on the left side may be 120° ahead of the phase of the current flowing through the current measurement module located in the center, and the phase of the current flowing through the current measurement module located on the right side may be 120° behind the phase of the current flowing through the current measurement module located in the center.

[0022] The above summary of the invention does not list all of the features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0023] [Figure 1] 1 is a perspective view showing an example of a schematic configuration of a current measuring module 100 according to a first embodiment. [Diagram 2] 1 is a top view showing an example of a schematic configuration of a current measurement module 100 according to a first embodiment. [Diagram 3] 1 is a side cross-sectional view showing an example of a schematic configuration of a current measurement module 100 according to a first embodiment. [Figure 4] 1 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). [Diagram 5] 1 is a graph showing the relationship between the center distance (mm) in the x direction between two magnetic detection elements 21 and 22 and the detected magnetic flux density (mT). [Figure 6] 1 is a graph showing the relationship between the center distance (mm) in the x direction between two magnetic detection elements 21 and 22 and the detected magnetic flux density (mT). [Figure 7] 4 is a top view showing another example of the schematic configuration of the current measurement module 100 according to the first embodiment. FIG. [Figure 8] 1 is a graph showing the relationship between the width in the x direction of a conductor 10 and two current paths 13 and 14 and the rate of fluctuation (%) of the detected magnetic flux density. [Figure 9] 1 is a graph showing the relationship between the width in the x direction of a conductor 10 and two current paths 13 and 14 and the rate of fluctuation (%) of the detected magnetic flux density. [Figure 10] 1 is a graph showing the relationship between the width in the x direction of a conductor 10 and two current paths 13 and 14 and the rate of fluctuation (%) of the detected magnetic flux density. [Figure 11] 1 is a graph showing the relationship between the width (mm) of two current paths 13, 14 and conductor 10 in the x direction and the rate of variation (%) of magnetic flux density from 100 Hz. [Figure 12] 1 is a graph showing the relationship between the width (mm) of two current paths 13, 14 and conductor 10 in the x direction and the rate of variation (%) of magnetic flux density from 100 Hz. [Figure 13] 1 is a graph showing the relationship between the width (mm) of two current paths 13, 14 and conductor 10 in the x direction and the rate of variation (%) of magnetic flux density from 100 Hz. [Figure 14] 1 is a graph showing the relationship between the width (mm) of two current paths 13, 14 and conductor 10 in the x direction and the rate of variation (%) of magnetic flux density from 100 Hz. [Figure 15] 1 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. [Figure 16] A first example of a method for fixing the magnetic detection unit 20 to the conductor 10 will be described. [Figure 17] A second example of a method for fixing the magnetic detection unit 20 to the conductor 10 will be described. [Figure 18] A third example of a method for fixing the magnetic detection unit 20 to the conductor 10 will be described. [Figure 19] 10 is a top view showing an example of a schematic configuration of a current measuring device 200 according to a second embodiment. FIG. [Figure 20] 11 is a top view showing an example of a schematic configuration of a current measuring device 300 according to a third embodiment. FIG. [Figure 21] FIG. 1 is a top view showing an example of a schematic configuration of a current measuring device 400 in a comparative example. [Figure 22] 10 is a graph showing frequency characteristics of a current measuring device 200 according to the second embodiment. [Diagram 23] 10 is a graph showing frequency characteristics of a current measuring device 200 according to the second embodiment. [Figure 24] 10 is a graph showing frequency characteristics of a current measuring device 200 according to the second embodiment. [Diagram 25] 11 is a graph showing frequency characteristics of a current measuring device 400 in a comparative example. [Figure 26] 11 is a graph showing frequency characteristics of a current measuring device 400 in a comparative example. [Figure 27] 11 is a graph showing frequency characteristics of a current measuring device 400 in a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0025] [Configuration of the first embodiment] FIG. 1 is a perspective view showing an example of a schematic configuration of a current measurement module 100 in the first embodiment. FIG. 2 is a top view showing an example of a schematic configuration of a current measurement module 100 in the first embodiment. FIG. 3 is a side cross-sectional view showing an example of a schematic configuration of a current measurement module 100 in the first embodiment. In each figure, an xyz coordinate system is shown. 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. As shown in FIG. 1 to FIG. 3, the current measurement module 100 has a conductor 10 and a magnetic detection unit 20. The conductor 10 has two main bodies 11 and 12 and two current paths 13 and 14, and a through hole 15 is formed by the two main bodies 11 and 12 and the two current paths 13 and 14. The conductor 10 is also called a bus bar. The magnetic detection unit 20 has two magnetic detection elements 21 and 22.

[0026] As shown in Figs. 1 to 3, the two main body parts 11, 12 are arranged side by side in the y direction. The two current paths 13, 14 are arranged between the two main body parts 11, 12, extend parallel to each other, and connect the two main body parts 11, 12. A through hole 15 is arranged between the two current paths 13, 14. A current to be measured flows in the same direction in each of the two current paths 13, 14. In this embodiment, the two current paths 13, 14 are conductors that have a rectangular cross-sectional shape and extend linearly. The cross-sectional shape of the two current paths 13, 14 may be any shape, such as a circle or an ellipse.

[0027] As shown in Fig. 2, the two current paths 13, 14 have the same width in the x direction. The width of the two current paths 13, 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. Since the influence of the skin effect increases as the two current paths 13, 14 become thicker, it is desirable that the width of the two current paths 13, 14 in the x direction be 4 mm or less. In addition, it is desirable that the thickness (width in the z direction) of the conductor 10 be 4 mm or less.

[0028] As shown in FIG. 2, 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 in a position close to one of the two current paths 13 and 14 in the x direction. In the example shown in FIG. 2, the two magnetic detection elements 21 and 22 are arranged in a position close to the current path 14 and far from the current path 13. That is, in FIG. 2, A>B. With such an arrangement, the strength of the magnetic field detected from the one current path 14 that is closer becomes larger, and the S / N ratio of the detected signal can be improved. Note that the two magnetic detection elements 21 and 22 may be arranged in a position close to the current path 13 and far from the current path 14.

[0029] The two magnetic detection elements 21, 22 detect the strength of the magnetic field generated on each magnetic sensing surface by the current to be measured flowing in the y direction through the two current paths 13, 14, respectively, and output a detection signal according to the difference in the detection strength detected by the two magnetic detection elements 21, 22. That is, in this embodiment, the detection signal output by the combination of the two magnetic detection elements 21, 22 is a differential output. The two magnetic detection elements 21, 22 are arranged so that the magnetic field generated by the current to be measured flowing in the same direction through the two current paths 13, 14 penetrates the magnetic sensing surface. The two magnetic detection elements 21, 22 are arranged between the two current paths 13, 14 so that the orientations of the magnetic sensing surfaces are aligned with each other. In this embodiment, the orientation of the magnetic sensing surface, i.e., the normal direction of the surface, is the z direction.

[0030] As shown in Fig. 2, when viewed from the z direction, the two magnetic detection elements 21, 22 are disposed in the through hole 15. As shown in Fig. 3, the magnetic detection unit 20 is disposed so that the magnetic sensing surfaces of the two magnetic detection elements 21, 22 are positioned 1 mm from the top surface of the conductor 10 in the z direction. The magnetic detection unit 20 is fixed to the conductor 10 by an insulating member or the like (not shown). The method of fixing the magnetic detection unit 20 to the conductor 10 will be described in the explanation sections of Figs. 15 to 17.

[0031] The two magnetic detection elements 21 and 22 may be magnetoelectric conversion elements, and as the magnetoelectric conversion elements, for example, Hall elements that can obtain a detection signal proportional to the magnitude of the magnetic flux density may be used. In addition to Hall elements, magnetic resistance elements, magnetic impedance elements, etc. may also be used as the magnetoelectric conversion elements. Furthermore, any element that can uniquely determine a detection signal for an applied magnetic flux density, such as a magnetic sensor IC that combines these magnetoelectric conversion elements with an IC processing circuit, may be used as the two magnetic detection elements 21 and 22. The two magnetic detection elements 21 and 22 may be different in shape and size.

[0032] FIG. 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. The graph in FIG. 4 shows the variation in magnetic flux density detected when one magnetic detection element 21 (or magnetic detection element 22) is moved in the x direction in the through hole 15. The horizontal axis of FIG. 4 shows the position (mm) of the center of the magnetic detection element 21 in the x direction, and the vertical axis shows the magnetic flux density (mT) detected by the magnetic detection element 21. In FIG. 4, the area where the numerical value on the horizontal axis is positive indicates that the magnetic detection element 21 is close to the current path 14, and the area where the numerical value on the horizontal axis is negative indicates that the magnetic detection element 21 is close to the current path 13. In FIG. 4, the point of 0 mm on the horizontal axis 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.

[0033] 4, 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. Also, the closer the magnetic detection element 21 is to the current path 14, the stronger the magnetic field in the opposite direction generated by the current flowing through the current path 14, and therefore the smaller the detected magnetic flux density. Furthermore, when the magnetic detection element 21 is disposed at the center of the current paths 13 and 14, the magnetic field generated by the current flowing through the current path 13 and the magnetic field generated by the current flowing through the current path 14 cancel each other out, and the detected magnetic flux density becomes zero. Note that, if the magnetic detection element 21 is placed too close to the current path 13, the z-direction component of the magnetic field generated by the current flowing through the current path 13 becomes smaller, and therefore the detected magnetic flux density becomes smaller.

[0034] 5 and 6 are graphs showing the relationship between the center coordinates (mm) of the two magnetic detection elements 21 and 22 in the x direction, which are the coordinates of the centers in the x direction, and the detected magnetic flux density (mT) for each center distance (mm) of the two magnetic detection elements 21 and 22 in the x direction. The horizontal axis of FIG. 5 shows 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 the reference (x=0). The vertical axis of FIG. 5 shows the magnetic flux density (mT) detected by the two magnetic detection elements 21 and 22 through differential output. The horizontal axis of FIG. 6 shows 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 the reference (x=0). The vertical axis of FIG. 6 shows the percentage (%) 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.

[0035] 5 and 6 indicate cases where the center distance in the x direction between the two magnetic detection elements 21 and 22 is 1 mm, the points indicated by squares indicate cases where the center distance in the x coordinates of the two magnetic detection elements 21 and 22 is 2 mm, the points indicated by diamonds indicate cases where the center distance in the x coordinates of the two magnetic detection elements 21 and 22 is 3 mm, and the points indicated by triangles indicate cases where the center distance in the x coordinates of the two magnetic detection elements 21 and 22 is 4 mm. Here, the center distance in the x direction between the two magnetic detection elements 21 and 22 is the distance in the x direction between the center of the magnetic detection element 21 and the center of the magnetic detection element 22, and is indicated by "C" in FIG.

[0036] As shown in FIG. 5, when the center distance is 4 mm, a magnetic flux density of about 6 mT or more is detected, but when the center distance is 1 mm, only a magnetic flux density of about 2 mT or less is detected. That is, the larger the center distance in the x direction of the two magnetic detection elements 21, 22, the larger the magnetic flux density detected by the differential output becomes. Also, as shown in FIG. 6, the more the x coordinates of the two magnetic detection elements 21, 22 are shifted from the center, the larger the change rate of the output ratio becomes. It is desirable from the viewpoint of the S / N ratio that the magnetic flux density detected is large. Therefore, the center distance in the x direction of the two magnetic detection elements 21, 22 is preferably large, for example, 2 mm or more. In other words, it is preferable that the center distance in the x direction of the two magnetic detection elements 21, 22 is 10% or more, 15% or more, or 25% or more of the width of the through hole 15 in the x direction.

[0037] 7 is a top view showing another example of the schematic configuration of the current measurement module 100 in the first embodiment. In order to improve the S / N ratio by ensuring the center distance in the x direction between the two magnetic detection elements 21 and 22, for example, as shown in FIG. 7, the two magnetic detection elements 21 and 22 may be arranged to face each other with respect to the center of the through hole 15. That is, the two magnetic detection elements 21 and 22 may be arranged so that they are located on opposite sides in the x direction with respect to the center line L of the through hole 15. In addition, the two magnetic detection elements 21 and 22 may be arranged to face each other across a region where magnetic fields generated by currents flowing through two current paths cancel each other out when a current flows through a conductor, and the magnetic flux density in the z direction detected becomes zero.

[0038] Furthermore, the two magnetic detection elements 21, 22 may be arranged such that the center distance in the x direction is greater than the distance between the center position in the x direction of the magnetic detection element (magnetic detection element 22 in FIG. 3) on the first current path side closer to the center position between the two magnetic detection elements and the end of the first current path (current path 14 in FIG. 3) closer to the center position between the two magnetic detection elements. That is, C>D in FIG. 3 may be satisfied.

[0039] 8 to 10 are graphs showing the relationship between the center coordinates (mm) of the two magnetic detection elements 21 and 22 in the x direction for each width in the x direction of the conductor 10 and the two current paths 13 and 14, and the fluctuation rate (%) of the detected magnetic flux density. The horizontal axis in FIG. 8 to FIG. 10 indicates the center positions (mm) of the two magnetic detection elements 21 and 22 in the x direction (i.e., the center positions of the magnetic detection elements 21 and 22 in the x direction), with the center of the through hole 15 as the reference (x=0). The vertical axis in FIG. 8 to FIG. 10 indicates the fluctuation rate (%) of the magnetic flux density detected by the two magnetic detection elements 21 and 22 when 100 Hz is used as the reference. The white circles in FIG. 8 to FIG. 10 indicate the fluctuation rate of the magnetic flux density at 1000 Hz, and the squares indicate the fluctuation rate of the magnetic flux density at 2000 Hz. Note that there is an area in FIG. 8 where the fluctuation rate exceeds 0%, which is not shown in the graph.

[0040] Fig. 8 shows case 1 in which the width in the x direction of the conductor 10 is 18 mm and the width in the x direction of the two current paths 13, 14 is 3 mm, Fig. 9 shows case 2 in which the width in the x direction of the conductor 10 is 24 mm and the width in the x direction of the two current paths 13, 14 is 4 mm, and Fig. 10 shows case 3 in which the width in the x direction of the conductor 10 is 30 mm and the width in the x direction of the two current paths 13, 14 is 4 mm. Note that in Figs. 8 to 10, the center distance in the x direction of the two magnetic detection elements 21, 22 is 3 mm, and the distance from the top surface of the conductor 10 to the position in the z direction of the magnetic sensing surfaces of the two magnetic detection elements 21, 22 is 1 mm.

[0041] Here, the fact that there are many regions where the rate of change in magnetic flux density at 2000 Hz is within -3% means that the detected value varies little with frequency, which is desirable from the viewpoint of frequency characteristics. Among cases 1 to 3, case 3 shown in Fig. 10 has the largest number of regions where the rate of change in magnetic flux density at 2000 Hz is within -3%. Therefore, among cases 1 to 3, case 3, in which the width in the x direction of conductor 10 is 30 mm and the width in the x direction of two current paths 13, 14 is 4 mm, is the most desirable.

[0042] In Fig. 8, the coordinates of both magnetic detection elements 21, 22 that are 1 mm or more away from the inner ends of the two current paths 13, 14 are in the region inside ±3 mm on the horizontal axis. In Fig. 9, the coordinates of both magnetic detection elements 21, 22 that are 1 mm or more away from the inner ends of the two current paths 13, 14 are in the region inside ±5 mm on the horizontal axis. In Fig. 10, the coordinates of both magnetic detection elements 21, 22 that are 1 mm or more away from the inner ends of the two current paths 13, 14 are in the region inside ±8 mm on the horizontal axis.

[0043] Here, the magnetic flux density fluctuates greatly in the region outside ±3 mm on the horizontal axis in Fig. 8, the region outside ±5 mm on the horizontal axis in Fig. 9, and the region outside ±8 mm on the horizontal axis in Fig. 10. This is because, if the two magnetic detection elements 21, 22 are placed too close to either of the two current paths 13, 14, they become susceptible to the skin effect, and the rate of fluctuation with frequency becomes large. Therefore, from the viewpoint of frequency characteristics, it is desirable to place either of the two magnetic detection elements 21, 22 1 mm or more away from the inner ends of the two current paths 13, 14 in the x direction.

[0044] 11 to 14 are graphs showing the relationship between the width (mm) of the two current paths 13, 14 and the conductor 10 in the x direction and the fluctuation rate (%) of the magnetic flux density from 100 Hz. The horizontal axis in FIG. 11 to FIG. 14 indicates the center position (mm) of the two magnetic detection elements 21, 22 in the x direction (i.e., the center position of the magnetic detection elements 21 and 22 in the x direction), with the center of the through hole 15 as the reference (x=0). The vertical axis in FIG. 11 to FIG. 14 indicates the fluctuation rate (%) of the magnetic flux density detected by the two magnetic detection elements 21, 22 when 100 Hz is used as the reference. The white circles in FIG. 11 to FIG. 14 indicate the case where the width of the two current paths 13, 14 in the x direction is 3 mm, the squares indicate the case where the width of the two current paths 13, 14 in the x direction is 4 mm, and the diamonds indicate the case where the width of the two current paths 13, 14 in the x direction is 5 mm. 11 to 14, the values ​​obtained by dividing the width of the two current paths 13, 14 in the x direction by the width of the conductor 10 in the x direction are shown on the right side.

[0045] Fig. 11 shows case 4 where the width of the conductor 10 in the x direction is 18 mm, Fig. 12 shows case 5 where the width of the conductor 10 in the x direction is 20 mm, Fig. 13 shows case 6 where the width of the conductor 10 in the x direction is 24 mm, and Fig. 14 shows case 7 where the width of the conductor 10 in the x direction is 30 mm. In Figs. 11 to 14, the frequency of the current flowing through the conductor 10 is 2000 Hz, the center distance in the x direction between the two magnetic detection elements 21 and 22 is 3 mm, and the distance in the z direction between the positions of the magnetic sensing surfaces of the two magnetic detection elements 21 and 22 in the z direction from the top surface of the conductor 10 is 1 mm. In Figs. 11 to 14, the more regions where the fluctuation rate of the magnetic flux density at 2000 Hz is within -3%, the more desirable it is from the viewpoint of frequency characteristics.

[0046] As shown in Fig. 11, in case 4 where the width of the conductor 10 in the x direction is 18 mm, when the width of the two current paths 13, 14 in the x direction is 3 mm, the fluctuation rate of the magnetic flux density is approximately -3%, which is a desirable value, but when the width of the two current paths 13, 14 in the x direction is 4 mm or 5 mm, the fluctuation rate exceeds -4%, which is undesirable. As shown in Fig. 12, 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, 14 in the x direction is 4 mm, the fluctuation rate is approximately -3%, which is a desirable value, but when the width of the two current paths 13, 14 in the x direction is 5 mm, the fluctuation rate is approximately -4%, which is undesirable.

[0047] As shown in Fig. 13, in case 6 where the width of the conductor 10 in the x direction is 24 mm, when the width of the two current paths 13, 14 in the x direction is 4 mm, the fluctuation rate is near -3%, which is a desirable value, but when the width of the two current paths 13, 14 in the x direction is 5 mm, the fluctuation rate exceeds -3%, which is undesirable. As shown in Fig. 14, 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, 14 in the x direction is 4 mm, the fluctuation rate is within -3%, which is a desirable value, and when the width of the two current paths 13, 14 in the x direction is 5 mm, the fluctuation rate is near -3%, which is also a desirable value.

[0048] From the above, desirable combinations of the widths of the conductor 10 and the two current paths 13, 14 are 18 mm and 3 mm in case 4, 20 mm and 4 mm in case 5, 24 mm and 4 mm in case 6, and 30 mm and 4 mm and 30 mm and 5 mm in case 7. Therefore, it can be seen that the fluctuation rate is desirable when the value obtained by dividing the width in the x direction of the two current paths 13, 14 by the width in the x direction of the conductor 10 is 20% or less.

[0049] If the current paths 13, 14 are thick, the influence of the skin effect becomes large, and the frequency characteristics deteriorate. Therefore, from the viewpoint of frequency characteristics, it is preferable that the current paths 13, 14 are thin. On the other hand, if the width of the conductor 10 is increased to widen the width of the through hole 15, the two magnetic detection elements 21, 22 can be separated from the current paths 13, 14, and the influence of the skin effect becomes relatively small, so that a location with good frequency characteristics can be selected. From the above, it is preferable in terms of frequency characteristics to reduce the width of the current paths 13, 14 or increase the overall width of the conductor 10 so that the ratio of the width of the current paths 13, 14 to the width of the conductor 10 is 20% or less.

[0050] 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. The horizontal axis of FIG. 15 indicates the position in the z direction of the magnetic sensing surface of the magnetic detection element 21, and is displayed with the top surface of the conductor 10 as the reference (z=0). The vertical axis of FIG. 15 indicates the magnetic flux density (mT) detected by the magnetic detection element 21. FIG. 15 shows the maximum magnetic field when a current of ±1000 A and 2000 Hz is passed through. A simulation was performed with the magnetic detection element 21 positioned 3.5 mm inside in the x direction from the current path 13, and the thickness of the conductor 10 in the z direction being 2 mm.

[0051] 15, the detected magnetic flux density decreases as the z coordinate of magnetic detection element 21 moves away from the top surface of conductor 10. If the detected magnetic flux density falls below 1 mT, the detection accuracy of current measurement module 100 is insufficient. Therefore, magnetic detection element 21 is desirably disposed so that the position of the magnetic sensing surface in the z direction is within 4 mm from the top surface of conductor 10. The same applies to magnetic detection element 22. Similarly, when two magnetic detection elements 21 and 22 are disposed on the -z direction side of conductor 10, it is desirably disposed so that they are within 4 mm from the bottom surface of conductor 10.

[0052] 16 shows a first example of a method for fixing the magnetic detection unit 20 to the conductor 10. As shown in FIG. 16, in the first example, the magnetic detection unit 20 is fixed to the conductor 10 via an insulating member 31 made of resin or the like. The insulating member 31 is disposed so as to cover the upper surface of the conductor 10 and fill the through hole 15. The magnetic detection unit 20 is fixed to the upper part of the insulating member 31.

[0053] 17 shows a second example of a method for fixing the magnetic detection unit 20 to the conductor 10. As shown in FIG. 17, in the second example, the magnetic detection unit 20 is fixed to the conductor 10 via an insulating member 32 made of resin or the like. The insulating member 32 is disposed so as to cover the lower surface of the conductor 10 and fill part of the through hole 15. The magnetic detection unit 20 is fixed to the upper part of the insulating member 32.

[0054] 18 shows a third example of a method for fixing the magnetic detection unit 20 to the conductor 10. As shown in FIG. 18, 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 disposed so as to cover the bottom and side surfaces of the conductor 10. The substrate 34 connected to the insulating member 33 is disposed on the top of the conductor 10, and the magnetic detection unit 20 is fixed to the bottom of the substrate 34.

[0055] 16 to 18, it is possible to prevent the magnetic detection unit 20 from shifting in the z-direction, thereby improving the measurement accuracy of the current measurement module 100. In addition, it is possible to make the current measurement module 100 small and simple in structure.

[0056] [Advantages of the First Embodiment] According to the current measurement module 100 of the first embodiment, the two magnetic detection elements 21, 22 are disposed in the x direction at positions close to one of the two current paths 13, 14. This makes it possible to ensure a sufficient magnetic flux density detected from one of the closer current paths, thereby improving the S / N ratio of the current measurement module 100.

[0057] According to the current measuring module 100 of the first embodiment, the center distance in the x direction between the two magnetic detection elements 21, 22 is 2 mm or more. This makes it possible to increase the magnetic flux density detected by the differential output, thereby improving the S / N ratio of the current measuring module 100.

[0058] According to the current measuring module 100 of the first embodiment, the width in the x direction of each of the two current paths 13, 14 is 20% or less of the width in the x direction of the conductor 10. This makes it possible to improve the frequency characteristics of the current measuring module 100.

[0059] According to the current measurement module 100 of the first embodiment, the two magnetic detection elements 21, 22 are arranged such that the position of the magnetic sensing surface in the z direction is within 4 mm from the upper surface of the conductor 10. This makes it possible to increase the magnetic flux density detected from the two current paths 13, 14, and improve the S / N ratio of the current measurement module 100.

[0060] According to the current measuring module 100 of the first embodiment, each of the two magnetic detection elements 21, 22 is disposed at a distance of 1 mm or more in the x direction from the inner ends of the two current paths 13, 14. This can improve the frequency characteristics of the current measuring module 100.

[0061] [Configuration of the second embodiment] Fig. 19 is a top view showing an example of a schematic configuration of a current measuring device 200 in the second embodiment. In the following description of the second embodiment, parts common to the current measuring module 100 in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in Fig. 19, 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 side by side in the x direction.

[0062] The phase of the current flowing through the current measurement module 100 arranged on the left lags behind the phase of the current flowing through the current measurement module 100 arranged in the center by 120°, and the phase of the current flowing through the current measurement module 100 arranged on the right lags behind the phase of the current flowing through the current measurement module 100 arranged in the center by 120°. The three current measurement modules 100 respectively correspond to the U phase, V phase, and W phase of the three-phase AC.

[0063] The central positions in the x direction of the two magnetic detection elements 21, 22 of the current measurement module 100 arranged on the left side are located close to the current path 14 on the side of the current measurement module 100 arranged in the center. The central positions in the x direction of the two magnetic detection elements 21, 22 of the current measurement module 100 arranged in the center are located close to the current path 14 on the side of the current measurement module 100 arranged on the right side. The central positions in the x direction of the two magnetic detection elements 21, 22 of the current measurement module 100 arranged on the right side are located close to the current path 13 on the side of the current measurement module 100 arranged in the center.

[0064] [Configuration of the third embodiment] Fig. 20 is a top view showing an example of a schematic configuration of a current measuring device 300 in the third embodiment. In the following description of the third embodiment, parts common to the current measuring module 100 in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in Fig. 20, 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 side by side in the x direction.

[0065] The phase of the current flowing through the current measurement module 100 arranged on the left side leads the phase of the current flowing through the current measurement module 100 arranged in the center by 120°, and the phase of the current flowing through the current measurement module 100 arranged on the right side lags the phase of the current flowing through the current measurement module 100 arranged in the center by 120°. The three current measurement modules 100 respectively correspond to the U phase, V phase, and W phase of the three-phase AC.

[0066] The central positions in the x direction of the two magnetic detection elements 21, 22 of the current measurement module 100 arranged on the left side are located close to the current path 14 on the side of the current measurement module 100 arranged in the center. The central positions in the x direction of the two magnetic detection elements 21, 22 of the current measurement module 100 arranged in the center are located close to the current path 13 on the side of the current measurement module 100 arranged on the left side. The central positions in the x direction of the two magnetic detection elements 21, 22 of the current measurement module 100 arranged on the right side are located close to the current path 13 on the side of the current measurement module 100 arranged in the center.

[0067] [Configuration of Comparative Example] Fig. 21 is a top view showing an example of a schematic configuration of a current measuring device 400 in a comparative example. In the following description of the comparative example, parts common to the current measuring module 100 in the first embodiment are given the same reference numerals and description thereof will be omitted. As shown in Fig. 21, 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 side by side in the x direction.

[0068] The phase of the current flowing through the current measurement module 100 arranged on the left side leads the phase of the current flowing through the current measurement module 100 arranged in the center by 120°, and the phase of the current flowing through the current measurement module 100 arranged on the right side lags the phase of the current flowing through the current measurement module 100 arranged in the center by 120°. The three current measurement modules 100 respectively correspond to the U phase, V phase, and W phase of the three-phase AC.

[0069] The two magnetic detection elements 21, 22 of the three current measurement modules 100 are arranged so that the central positions in the x direction of the two magnetic detection elements 21, 22 coincide with the center of the through hole 15. That is, in the comparative example, the two magnetic detection elements 21, 22 are not arranged so as to be close to either of the current paths 13, 14.

[0070] Fig. 22 to Fig. 27 are graphs 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. Fig. 22 to Fig. 24 respectively show 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, and Fig. 25 to Fig. 27 respectively show 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. The horizontal axis of Fig. 22 to Fig. 27 shows the frequency (Hz) of the current flowing through the current measuring module 100, and the vertical axis shows the rate of variation (%) of the magnetic flux density when 100 Hz is used as the reference.

[0071] As shown in Fig. 22, in the U-phase current measurement module 100 of the current measurement device 200, the magnetic flux density hardly fluctuates at 1000 Hz, and the decrease is limited to about -3% at 10000 Hz. In contrast, as shown in Fig. 25, in the U-phase current measurement module 100 of the current measurement 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 U-phase current measurement module 100, the current measurement device 200 of the second embodiment has better frequency characteristics than the current measurement device 400 of the comparative example.

[0072] As shown in Fig. 23, in the V-phase current measurement module 100 of the current measurement device 200, the magnetic flux density hardly fluctuates at 1000 Hz, and drops to about -5% at 10,000 Hz. In contrast, as shown in Fig. 26, in the V-phase current measurement module 100 of the current measurement device 400, the magnetic flux density drops to about -1.5% at 1000 Hz, and drops to about -5% at 10,000 Hz. Therefore, it can be seen that, in the V-phase current measurement module 100, the current measurement device 200 of the second embodiment has better frequency characteristics than the current measurement device 400 of the comparative example.

[0073] As shown in Fig. 24, in the W-phase current measurement module 100 of the current measurement device 200, the magnetic flux density hardly fluctuates at 1000 Hz, and the decrease is limited to about -1% at 10000 Hz. In contrast, as shown in Fig. 27, in the W-phase current measurement module 100 of the current measurement device 400, the magnetic flux density decreases to about -1.5% at 1000 Hz, and to about -4.5% at 10000 Hz. Therefore, it can be seen that, in the W-phase current measurement module 100, the current measurement device 200 of the second embodiment has better frequency characteristics than the current measurement device 400 of the comparative example.

[0074] From the above, it can be seen that for all of the U, V, and W phases, the current measuring device 200 in the second embodiment has better frequency characteristics than the current measuring device 400 in the comparative example, and therefore the arrangement of the current measuring device 200 in the second embodiment is preferable. Note that, like the current measuring device 200 in the second embodiment, the current measuring device 300 in the third embodiment also has better frequency characteristics than the current measuring device 400 in the comparative example.

[0075] [Advantages of the second and third embodiments] According to the current measuring device 200 of the second embodiment and the current measuring device 300 of the third embodiment, three current measuring modules 100 are arranged side by side in the x direction, and two magnetic detection elements 21, 22 of the three current measuring modules 100 are arranged in positions close to either of the current paths 13, 14. This makes it possible to improve the frequency characteristics of the current measuring device 200 and the current measuring device 300.

[0076] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention.

[0077] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and may be realized in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is explained using "first," "next," etc. for convenience, it does not mean that it is essential to perform the process in this order. [Explanation of symbols]

[0078] 10 Conductors 11,12 Main body 13,14 Current Path 15 Through hole 20 Magnetic detection unit 21, 22 Magnetic detection element 31~33 Insulating materials 34 Substrate 100 Current Measurement Module 200,300,400 Current measuring device

Claims

1. A conductor having two main body portions arranged side by side in a first direction, and two current paths arranged side by side across a through hole in a second direction perpendicular to the first direction, connecting the two main body portions; two magnetic detection elements arranged side by side in the second direction, the magnetic detection elements including a magnetic sensing surface for detecting a component in a third direction perpendicular to the first direction and the second direction of a magnetic field generated by currents flowing through the two current paths; Equipped with When viewed from the third direction, the two magnetic detection elements are disposed inside the through hole, A current measurement module, wherein in the second direction, a center position between the two magnetic sensing elements is close to one of the two current paths.

2. The current measurement module of claim 1 , wherein the center distance in the second direction between the two magnetic sensing elements is 2 mm or more.

3. The distance in the second direction between the two magnetic detection elements is The current measurement module according to claim 1 , wherein the width is 15% or more of the width of the through hole in the second direction.

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

5. The current measurement module of 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 of claim 1 , wherein the widths of the two current paths in the second direction are the same.

7. 2. The current measurement module according to claim 1, wherein the positions of the magnetic sensitive surfaces of the two magnetic detection elements in the third direction are within a range of 4 mm from the top surfaces of the two current paths.

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

9. a current path closer to a center position between the two magnetic detection elements in the second direction is defined as a first current path; The current measurement module according to claim 1 , wherein each of the two magnetic detection elements is disposed 1 mm or more away from an inner end of the first current path.

10. a current path closer to a center position between the two magnetic detection elements in the second direction is defined as a first current path; 2. The current measurement module of claim 1, wherein 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.

11. The current measurement module according to claim 1 , wherein the two magnetic detection elements are disposed opposite each other with respect to a center of the through hole in the second direction.

12. 2. The current measurement module of claim 1, wherein the two magnetic detection elements are arranged opposite each other across a region in which, when a current flows through the conductor, magnetic fields generated by currents flowing through the two current paths cancel each other out in the second direction, causing the magnetic flux density detected in the third direction to be zero.

13. 2. The current measurement module of claim 1, wherein the two magnetic sensing elements are Hall elements.

14. 2. The current measurement module of claim 1, further comprising an insulating member that secures the two magnetic sensing elements to the conductor.

15. The current measurement module of claim 1 , further comprising a substrate that secures the two magnetic sensing elements to the conductor.

16. a current measuring module including three current measuring modules according to claim 1 arranged side by side in the second direction; In the second direction, the center positions of the two magnetic detection elements of the current measurement module arranged on the left side are located close to the current path on the side of the current measurement module arranged in the center, the center positions of the two magnetic detection elements of the current measurement module arranged in the center are located close to the current path of the current measurement module arranged on the right side, A current measuring device, wherein the center positions of the two magnetic detection elements of the current measuring module arranged on the right side are arranged in a position close to the current path on the side of the current measuring module arranged in the center.

17. the phase of the current flowing through the current measurement module arranged on the left side is delayed by 120° from the phase of the current flowing through the current measurement module arranged in the center, and the phase of the current flowing through the current measurement module arranged on the right side is advanced by 120° from the phase of the current flowing through the current measurement module arranged in the center; 17. The current measuring device according to claim 16.

18. a current measuring module including three current measuring modules according to claim 1 arranged side by side in the second direction; In the second direction, the center positions of the two magnetic detection elements of the current measurement module arranged on the left side are located close to the current path on the side of the current measurement module arranged in the center, the center positions of the two magnetic detection elements of the current measurement module arranged in the center are located close to the current path of the current measurement module arranged on the left side, A current measuring device, wherein the center positions of the two magnetic detection elements of the current measuring module arranged on the right side are arranged in a position close to the current path on the side of the current measuring module arranged in the center.

19. the phase of the current flowing through the current measurement module arranged on the left side is advanced by 120° from the phase of the current flowing through the current measurement module arranged in the center, and the phase of the current flowing through the current measurement module arranged on the right side is delayed by 120° from the phase of the current flowing through the current measurement module arranged in the center; 20. The current measuring device of claim 18.

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