Rogowski type current sensor, inverter and method for installing Rogowski type current sensor

Abstract

The present invention provides a Rogowski current sensor, an inverter, and a method for installing the Rogowski current sensor, which can be flexibly deformed and easily installed even in a narrow gap. The main body 10 of the Rogowski current sensor 100 is formed by a strip-shaped flexible wiring substrate. The main body 10 has a measuring part in which a Rogowski coil is formed along the length direction according to a conductive pattern. When measuring the current flowing in the wiring of the measured object, the main body 10 is installed in such a way that the main body 10 is bent into a ring shape to surround the wiring of the measured object so that the front faces (first main faces 1S) overlap with each other.

Description

Technical Field

[0001] The present invention relates to a Rogowski type current sensor for measuring current distribution, an inverter and a method for installing the Rogowski type current sensor. Background Art

[0002] A CT (current transformer) is used as a sensor to detect the current size. It is a coil wound on a ring-shaped iron core to detect the current passing through the center of the iron core. However, it has disadvantages such as being unable to be miniaturized due to the use of an iron core, and increasing the measurement error of large currents due to magnetic saturation. The current sensor using the Rogowski coil is an air core, so it has the advantages of no magnetic saturation and can be miniaturized. For highly integrated and high-current power devices such as IGBT (Insulated Gate Bipolar Transistor), the Rogowski type current sensor is considered to be more suitable.

[0003] The Rogowski current sensor detects current by bending a measuring portion formed with a Rogowski coil into a ring shape to surround a wiring to be measured. This type of Rogowski current sensor is known and described in Patent Documents 1 to 4.

[0004] The conventional Rogowski current sensor described in Patent Document 1 has a notch for inserting a measured circuit through a hole in the annular substrate in a non-wiring portion of an annular four-layer build-up printed wiring substrate (annular substrate) on which a Rogowski coil is formed.

[0005] In addition, the conventional Rogowski type current sensor described in Patent Documents 2 to 4 inserts the front end of the sensor cable into an insertion port formed on a retaining portion on which the base end of the sensor cable for detecting the current flowing in the measurement object is installed, and detects the current flowing in the measurement object in a state of surrounding the measurement object.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 6709918

[0009] Patent Document 2 Japanese Patent Application Publication No. 2020-076706

[0010] Patent Document 3: Japanese Patent Application Publication No. 2020-076707

[0011] Patent document 4: Japanese Patent Application Publication No. 2019-196962. Summary of the invention

[0012] Problem that the invention aims to solve

[0013] The conventional Rogowski type current sensor described in Patent Document 1 measures the current flowing in the electric wire by shifting the printed wiring board in the thickness direction from the notch position to form a gap and inserting the wire through the hole of the printed wiring board from the notch position.

[0014] However, it is difficult to deviate a rigid printed wiring board in the thickness direction to form a gap for inserting into the hole of the printed wiring board to flexibly surround the electric wire.

[0015] Conventional Rogowski type current sensors described in Patent Documents 2 to 4 cover a Rogowski coil formed by spirally winding a conducting wire around a hollow flexible member made of a synthetic resin such as vinyl chloride or polyethylene with a resin material such as fluororesin.

[0016] Therefore, if the conventional Rogowski type current sensor described in Patent Documents 2 to 4 is repeatedly measured, the hollow flexible member may be damaged, and the helically wound Rogowski coil may be damaged. In addition, the hollow flexible member has a certain thickness, so it is difficult to insert the sensor cable when the gap between the wirings is narrow.

[0017] Therefore, an object of the present invention is to provide a Rogowski type current sensor, an inverter, and a method for mounting the Rogowski type current sensor that are flexible and can be easily mounted even in a narrow gap.

[0018] Solutions for solving problems

[0019] The Rogowski current sensor of the present invention is characterized by comprising a main body formed of a strip-shaped flexible wiring substrate and capable of surrounding a current path to be measured, and a measuring portion having a Rogowski coil formed along a longitudinal direction according to a conductive pattern.

[0020] According to the Rogowski type current sensor of the present invention, the main body is formed of a flexible wiring substrate, so even if the main body is bent to surround the current path of the measurement object, it can be flexibly deformed repeatedly. Since the strip-shaped flexible wiring substrate is formed thin, it can be inserted and wound around the measurement object such as the wiring even in a narrow gap.

[0021] The main body may be provided with a positioning portion that allows the base end portion and the tip end portion of the Rogowski coil to overlap when surrounding a current path of the measurement object.

[0022] When the main body surrounds the object to be measured, the base end and the tip end of the Rogowski coil can be overlapped by the positioning portion, so that a signal corresponding to the current of the wiring can be accurately output from the Rogowski coil.

[0023] A grid-like mesh formed according to a conductive pattern and intersecting the longitudinal direction may be formed on a pair of layers sandwiching the Rogowski coil.

[0024] When the main body is bent, the rigidity can be suppressed compared to when the metal wire is extended in the longitudinal direction. Therefore, the shielding layer can shield the influence of the electric field change caused by the voltage fluctuation of the measured object and reduce the force when the main body is bent.

[0025] A soft portion (shielding layer removed portion) may be formed along the longitudinal direction of the main body at the front end portion of the main body, that is, at the front side of the measuring portion.

[0026] Since the soft portion is formed at the front end portion, the rigidity of the flexible wiring substrate can be reduced, and thus the front end portion can be easily bent.

[0027] The Rogowski coil may be configured such that, in the Rogowski coil, each coil constituting the Rogowski coil is arranged along a closed line formed when the coils are arranged along a current path surrounding the object to be measured, and between the winding end of a coil among adjacent coils and the winding start end of the next coil, a plurality of coils are continuously connected by a forward line parallel to the closed line, and a return line parallel to the closed line is provided from the winding end of the last coil among the plurality of coils to the winding start end side of the first coil, and the coil is composed of a first side having the winding end of the coil and the winding start end of the next coil, and a second side located on the opposite side of the first side. A third side and a fourth side are formed by connecting the two ends of the first side and the second side to each other, and either the third side or the fourth side is formed at a position offset from a plane that includes the other side and is orthogonal to the closed line. If the value representing the coil spacing between the coils is set to Wp, the value representing the offset between the third side and the fourth side is set to Ws, the value representing the height from the second side to the first side is set to T1, and the value representing the height from the return line to the first side is set to T2, then the relationship of 0<Ws<2×Wp×T2 / T1 is achieved.

[0028] If the offset Ws is greater than 0, a plane surrounded by the first side, the second side, the third side, and the fourth side appears and is formed. Therefore, since a normal vector of the plane is generated, the influence of the magnetic flux passing through the plane sandwiched by the outbound line and the return line between the coil spacing can be reduced. In addition, if the offset Ws is greater than 2×Wp×T2 / T1 (greater than or equal to), the area of ​​Ws×T1 is too large, and the influence on the magnetic flux becomes worse than when the offset Ws is 0.

[0029] Therefore, in order to reduce the adverse effect of the magnetic flux from the plane of Wp×T2, the relationship of 0<Ws<2×Wp×T2 / T1 can be set.

[0030] The flexible wiring substrate can be set to have at least three conductive pattern layers, each coil is formed by a first coil pattern formed on the first layer and serving as the outbound line and the first side connected to the outbound line, a second coil pattern formed on the third layer and serving as the second side parallel to the first coil pattern, and a pair of through holes connecting the respective ends of the first coil pattern and the second coil pattern to each other as the third side and the fourth side, and the outbound line is formed on the second layer between the two layers consisting of the first layer and the third layer.

[0031] As described above, the Rogowski coil of the present invention can be constructed by a flexible wiring substrate having at least three conductive pattern layers.

[0032] The offset amount Ws and the coil pitch Wp may be in a relationship of Ws×T1=Wp×T2.

[0033] The normal vector of the plane of Wp×T2 is cancelled by the reverse normal vector of the plane of Ws×T1. Therefore, the Rogowski current sensor of the present invention can reduce the generation of noise and can accurately measure the current.

[0034] The main body may include a signal extraction pad formed at a base end portion, and a connection pattern connected to the first coil and a connection pattern connected to the return line may be formed at positions overlapping in a thickness direction.

[0035] Since the loop area can be reduced when viewed in the thickness direction, parasitic inductance can be reduced and noise resistance can be improved.

[0036] The first coil pattern may be formed in a direction perpendicular to the closed line, the return line may be formed in parallel with the closed line, and the second coil pattern may be formed in a crank shape by connecting a pair of patterns extending from both ends in a direction perpendicular to the closed line using a pattern formed in parallel with the closed line. Thus, when the Rogowski coil is observed from the thickness direction (from above), the plane serving as the coil cannot be seen, thereby improving noise resistance.

[0037] When the main body is used to surround the current path of the measurement object and the base end and the front end of the Rogowski coil are opposite to each other, the base end and the front end of the Rogowski coil are not in contact with each other and are formed at the same position or close to each other.

[0038] The interval in the thickness direction when the base end and the front end of the Rogowski coil face each other may be set to be less than (less than or equal to) 1 mm. In addition, the interval in the length direction when the base end and the front end of the Rogowski coil face each other may be set to be less than ±1 mm.

[0039] This makes it possible to measure the current flowing through the current path to be measured with high accuracy.

[0040] The device may include a fixing means for fixing the base end portion and the tip end portion of the Rogowski coil in an overlapping state when the current path of the measurement object is surrounded by the main body.

[0041] By providing such a fixing member, when measuring the current of the measurement object, the base end portion and the tip end portion of the Rogowski coil can be prevented from being shifted from the overlapping state.

[0042] It can be set that in the main body, a recessed portion, a through hole, or a fitted portion consisting of a convex portion is formed on any one of the base end portion or the front end portion of the main body, the fixing member is formed with an insertion hole that can overlap with the other by inserting the one, and a convex portion that fits with the recessed portion or the through hole of the fitted portion, or a fitting portion consisting of a recessed portion or a through hole that fits with the convex portion of the fitted portion is formed on the inner wall of the insertion hole, and when the fitting portion is fitted into the fitted portion, the base end portion and the front end portion of the Rogowski coil overlap.

[0043] The engaged portion and the engaging portion function as a position aligning portion, thereby enabling the base end portion and the front end portion of the Rogowski coil to be reliably overlapped, and the front end portion and the base end portion of the main body portion to be fixed in an overlapped state.

[0044] The fixing member may be provided with an insertion hole which can overlap with the other by inserting either the base end portion or the front end portion of the main body, and a stop portion is formed in the insertion hole, which prevents the insertion at a position where the base end portion and the front end portion of the Rogowski coil overlap when one of the two is inserted.

[0045] When either the base end portion or the front end portion of the main body portion is inserted into the insertion hole, the insertion of one of them is stopped by the stopper portion, so that the base end portion and the front end portion of the Rogowski coil can be fixed in an overlapping state.

[0046] The inverter of the present invention is characterized in that it has a Rogowski-type current sensor and a current measuring circuit of the present invention, and the current measuring circuit measures the current flowing in the current path by winding the output of the Rogowski-type current sensor by using either or both of the upper bridge arm or the lower bridge arm connected in series between one power line and the other power line from the power source as the current path.

[0047] As described above, by installing the Rogowski type current sensor of the present invention on the upper bridge arm and the lower bridge arm, the current flowing in the upper bridge arm and the lower bridge arm can be monitored to control the output current of the inverter, or excessive current flowing in the upper bridge arm and the lower bridge arm can be detected and an alarm can be issued.

[0048] In addition, the method for installing a Rogowski-type current sensor of the present invention is to install a Rogowski-type current sensor having a first main surface, a second main surface opposite to the first main surface, and a pair of side surfaces and having a flexible strip-shaped main body, and a Rogowski coil buried in the main body, on a current path of a measurement object through which current flows, and is characterized in that, with respect to the current path of the measurement object, the Rogowski-type current sensor is installed in a manner that surrounds the current path of the measurement object so that one of the first main surface or the second main surface becomes the inner side.

[0049] In this way, the Rogowski-type current sensor of the present invention can be installed on a current line.

[0050] A linear body may be directly or indirectly connected to one end of the Rogowski current sensor, and after the linear body is inserted into a gap between the current path of the measurement object and other components, the Rogowski current sensor may be wound around and installed on the current path of the measurement object by moving the linear body.

[0051] Therefore, even if there is a narrow gap between the current path of the measurement object and other components, the Rogowski type current sensor can be easily installed in the current path of the measurement object by first allowing a linear body directly or indirectly connected to the end of the Rogowski type current sensor to pass through the gap and then pulling the Rogowski type current sensor so that the Rogowski type current sensor is located in the gap.

[0052] In addition, the Rogowski type current sensor is mounted on a current path of a measurement object by surrounding the marking portions formed at both ends of the Rogowski type current sensor as a reference, and the Rogowski type current sensor includes a main body portion, the main body portion is formed of a strip-shaped flexible wiring substrate, and has a measurement portion in which a Rogowski coil is formed along a length direction according to a conductive pattern. Thus, mounting becomes easy and characteristic deviation can be suppressed.

[0053] Effects of the Invention

[0054] According to the Rogowski current sensor of the present invention, since the tape-shaped flexible wiring substrate is thin, it can be inserted even in a narrow gap and wound around a measurement object such as a wiring, so it can be flexibly deformed and can be easily installed even in a narrow gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] 1 is a perspective view showing a state where a Rogowski-type current sensor according to an embodiment of the present invention is wound around a current path, Figure 1A 2 is a diagram showing a state in which the front surfaces (first main surfaces) of the main body parts are overlapped with each other. Figure 1B This is a diagram showing a state in which the front surface (first principal surface) of the distal end portion and the back surface (second principal surface) of the proximal end portion are overlapped.

[0056] Figure 2A is a diagram of a flexible configuration substrate constituting the Rogowski type current sensor shown in FIG. 1 , Figure 2B is a diagram for explaining a cover film disposed on the front surface (first main surface) side of a flexible wiring substrate. Figure 2C This is a diagram for explaining a cover film disposed on the back surface (second main surface) side of a flexible wiring substrate.

[0057] Figure 3 It is used to form Figure 2A FIG. 2 is a diagram for explaining the principle of a Rogowski coil on a flexible wiring substrate shown in FIG.

[0058] Figure 4 is used for Figure 2A FIG. 1 is a diagram for explaining a shielding layer of a flexible wiring substrate, Figure 4A This is a picture of the shield layer on the front side. Figure 4B This is a picture of the shield layer on the back side. Figure 4C This is a partial enlarged view of the shielding layer's mesh.

[0059] Figure 5A It is used for Figure 2A FIG. 1 is a diagram for explaining the first layer of the flexible wiring substrate shown in FIG. Figure 5B yes Figure 5A A partial enlarged view of .

[0060] Fig. 6A It is used for Figure 2A FIG. 2 is a diagram for explaining the second layer of the flexible wiring substrate shown in FIG. Figure 6B yes Fig. 6A A partial enlarged view of .

[0061] Fig. 7A It is used for Figure 2A FIG. 3 is a diagram for explaining the third layer of the flexible wiring substrate shown in FIG. Figure 7B yes Fig. 7A A partial enlarged view of .

[0062] Figure 8 It is used for Figure 2A A diagram for explaining the structure of a flexible wiring board shown in FIG.

[0063] 9 is a diagram showing a state in which the base end portion and the front end portion of the Rogowski coil of the Rogowski type current sensor shown in FIG. 1 are overlapped, Fig.9A This is a diagram for explaining the interval in the thickness direction. Fig. 9B This is a diagram for explaining the interval in the longitudinal direction.

[0064] Fig.10 This is a diagram showing an example of how the Rogowski coil of the Rogowski type current sensor shown in FIG. 1 is positioned and fixed, and is a diagram showing a state where the base end portion and the tip end portion of the main body portion are fixed by the housing.

[0065] FIG. 11 is a diagram showing an example of aligning and fixing the position of the Rogowski coil of the Rogowski type current sensor shown in FIG. 1 , Fig.11A This is a diagram of the case where the shell that penetrates the base end of the main body is inserted into the front end. Fig. 11B yes Fig.11A The figure shows a state in which the front end portion of the main body is inserted into the insertion hole of the housing.

[0066] FIG. 12 is a diagram showing an example of aligning and fixing the position of the Rogowski coil of the Rogowski type current sensor shown in FIG. 1 , Fig. 12A This is a diagram of the case where the shell that penetrates the base end of the main body is inserted into the front end. Fig. 12B yes Fig. 12A The figure shows a state in which the front end portion of the main body is inserted into the insertion hole of the housing.

[0067] Fig.13A This is a diagram for explaining the principle of a conventional Rogowski coil. Fig. 13B This is a schematic diagram of a conventional Rogowski coil as viewed from the thickness plane.

[0068] Figure 14 is used for Figure 3 The pattern of the Rogowski coil is shown in the figure for explanation, Fig.14A is a diagram for explaining the first coil pattern of the first layer, Fig. 14B is a diagram for explaining the through hole of the second layer, Fig. 14C It is a diagram for explaining the second coil pattern of the third layer.

[0069] Fig.15 Observed from the thickness Figure 3 A schematic diagram of a Rogowski coil is shown.

[0070] Fig.16 This is a graph for explaining the range of the effect obtained by the Rogowski coil shown in FIG. 1 .

[0071] Fig.17 It is used for Fig.16 This is a graph for explaining the range of the effect obtained when the via hole pitch error is taken into consideration.

[0072] Fig.18 Observed from above Figure 3 Diagram of a Rogowski coil shown.

[0073] FIG. 19 is a diagram for explaining a variation of the Rogowski coil. Fig.19A is a diagram for explaining the first coil pattern of the first layer, Fig.19B is a diagram for explaining the through hole of the second layer, Fig.19C It is a diagram for explaining the second coil pattern of the third layer.

[0074] Fig. 20 It is used to explain the installation of the upper bridge arm and the lower bridge arm as the current path. Figure 1A or Figure 1B FIG. 1 is a diagram of an inverter that uses a Rogowski type current sensor and a current measurement circuit to measure the current flowing in the current path.

[0075] Fig.21 It means that Figure 1A or Figure 1B The illustrated perspective view is a state where the Rogowski type current sensor is not attached to a current path to be measured.

[0076] Fig. 22 It means to make Figure 1A or Figure 1B The illustrated perspective view shows a state where a Rogowski type current sensor is located in a current path to be measured. DETAILED DESCRIPTION

[0077] A Rogowski type current sensor according to an embodiment of the present invention will be described with reference to the drawings.

[0078] Figure 1A and Figure 1B The Rogowski current sensor 100 shown in the figure is used to surround the wiring W (current path) of the measurement object to measure the current flowing in the wiring W. When the Rogowski current sensor 100 is used to surround the wiring W, the Figure 1A As shown, the front faces (first main faces 1S) are overlapped with each other, or as shown Figure 1B As shown, the front side (first main surface 1S) of the front end portion 11 and the back side (second main surface 2S) of the base end portion 12 are overlapped. Figure 1A and Figure 1B The Rogowski current sensor 100 can be used differently according to the equipment to be installed, the specifications of the module or the use environment.

[0079] Although not shown, the back surfaces (second main surfaces 2S) may overlap each other, and the back surface (second main surface 2S) of the tip portion 11 and the front surface (first main surface 1S) of the base portion 12 may overlap each other.

[0080] Figure 2A The Rogowski current sensor 100 shown includes a main body 10 formed of a tape-shaped flexible wiring substrate.

[0081] The main body 10 is a flexible five-layer structure in which resin films and conductive patterns are alternately arranged (see Figure 8 , first to third layers + shielding layer × two layers) substrate. The main body 10 is initially formed in a straight line.

[0082] The length of the main body 10 from the front end 10a to the base end 10b is about 10 cm. The narrow width of the front end 10a of the main body 10 is about 2 mm, and the wide width of the base end 10b is about 6 mm.

[0083] The main body 10 comprises: a front end portion 11 having a long hole 111 formed along the length direction F1 and serving as a soft portion; a base end portion 12 having a welding pad 121 (terminal portion) for mounting a connecting plug and being wider than the front end portion 11; and a measuring portion 13 located between the front end portion 11 and the base end portion 12 and having a Rogowski coil C formed thereon.

[0084] In addition, at the front end of the long hole 111 formed in the front end portion 11, a first position alignment portion 14a as one side of the position alignment portion 14 (marking portion) is formed by a pad, and the position alignment portion 14 is used to overlap the base end portion C1 and the front end portion C2 of the Rogowski coil C when the main body portion 10 is bent into a circular ring shape to surround the wiring. In addition, at the base end portion 12, a second position alignment portion 14b as the other side of the position alignment portion 14 is formed by a pad.

[0085] The position alignment unit 14 is Figure 2B and Figure 2C The through holes 15c formed in the coatings 15a and 15b as the surface layers on the front and back surfaces are exposed.

[0086] As described above, the positioning portions 14 (marking portions) are formed at both ends of the Rogowski type current sensor.

[0087] Figure 2AThe bonding pad 121 shown includes a first pad 121 a (signal extraction pad) for outputting a signal from the Rogowski coil C, and a second pad 121 b for connecting to a shield layer described later and grounding.

[0088] The first pad 121 a is connected to the forward path and the return path of the Rogowski coil C via a pair of connection patterns 123 .

[0089] Here, the Rogowski coil C formed in the measuring unit 13 will be described.

[0090] like Figure 2A As shown, the Rogowski coil C is formed when the base end C1 and the front end C2 of the Rogowski coil C overlap. Figure 3 The closed line L shown continuously connects the coils 1 constituting the plurality of coils (Rogowski coils C) through a forward line 2 parallel to the closed line L between the winding end of one coil in adjacent coils and the winding start end of the next coil.

[0091] In addition, the Rogowski coil C has a return line 3 parallel to the closed line L from the winding end of the last coil of the plurality of coils to the winding start end side of the first coil.

[0092] The return line 3 is arranged closer to the outbound line 2 than the coil portion side located on the opposite side of the outbound line 2 .

[0093] The Rogowski coil C utilizes Figure 2A The main body 10 (measurement unit 13) shown in the figure is formed by a conductive pattern formed on a flexible wiring substrate. The flexible wiring substrate can use a flexible wiring substrate having at least three conductive pattern layers.

[0094] First, on the surface of the main body 10, that is, Figure 2B The coating 15a as the first main surface and the coating 15b as the second main surface opposite to the first main surface are shown. Figure 2C On the inner layer side of the coating 15b shown in the figure, a pair of layers, namely, shielding layers S, are formed to sandwich the Rogowski coil C in the thickness direction (see Figure 4A and Figure 4B ).like Figure 4C As shown in FIG. 1 , a lattice-shaped mesh S1 intersecting the longitudinal direction F1 is formed on the shield layer S. In the present embodiment, the mesh S1 is inclined at 45 degrees with respect to the longitudinal direction F1.

[0095] In addition, if Figure 4A As shown in FIG. 1 , the shield layer S is provided with the above-mentioned soldering pads 121 .

[0096] On the inner layer of the pair of shielding layers S, as Figure 3 , Figure 5Aand Figure 5B As shown, as the first layer (reference Figure 8 ) is formed with a first coil pattern 1A (first side 1a), one end of a through hole connected to the first coil pattern 1A, namely one of the connecting portions 1C', 1D', an outbound line 2, and a connecting pattern 123.

[0097] In addition, if Figure 3 , Fig. 6A and Figure 6B As shown, the second layer of the inner layer of a pair of shielding layers S (reference Figure 8 ), forming through holes 1C, 1D (third side 1c, fourth side 1d), and a return line 3 that connect the first coil pattern 1A to the second coil pattern 1B described later.

[0098] In addition, a layer without pattern formation is provided as a blank layer to be laminated on the second layer.

[0099] In addition, if Figure 3 , Fig. 7A and Figure 7B As shown, as the third layer stacked on the blank layer (reference Figure 8 ), forming a second coil pattern 1B (second side 1b), and the other end of the through hole connected to the second coil pattern 1B, namely another connecting portion 1C", 1D".

[0100] By forming the flexible wiring substrate in this way, the distance between the outbound line 2 of the first layer and the return line 3 of the second layer is formed to be 37.5 μm by the base film (12.5 μm) and the bonding sheet (25 μm). The distance between the return line 3 of the second layer and the coil portion on the opposite side of the outbound line 2, that is, the second coil pattern 1B of the third layer, is formed to be 125 μm by the base film (50 μm), the bonding sheet (25 μm) and the base film (50 μm).

[0101] As described above, the outbound line 2 and the return line 3 have the same path when viewed from above, and differ only in height. The return line 3 is routed closer to the outbound line 2 than the second coil pattern 1B (second side 1 b ).

[0102] When the main body 10 of the Rogowski current sensor 100 is used to surround the current path (wiring W) of the object to be measured and measure the current, Fig.9AAs shown, the base end C1 of the Rogowski coil C does not contact the front end C2, and is located at the same position or a close position. At this time, the interval K1 can be set to be less than 1.5 mm in the thickness direction, preferably less than 1 mm. That is, since the Rogowski type current sensor 100 is constructed by laminating a flexible resin film on the Rogowski coil C as described above, the Rogowski coil C is in a state where at least two sides are clamped by the resin film or the like. At this time, if the base end C1 and the front end C2 of the Rogowski coil C are overlapped to form a ring, the base end C1 and the front end C2 of the Rogowski coil C can be in a non-contact state with at least the thickness of the resin film between them. In addition, when the interval K1 is to be adjusted, it is possible to consider inserting a spacer separately, adjusting the amount of adhesive applied, or reducing the resin film or the like.

[0103] In addition, if Fig. 9B As shown, the interval K2 can be set to be less than ±1.5 mm in the length direction, preferably less than ±1 mm.

[0104] In addition, if Figure 1A As shown in the figure, the first position alignment portion 14a and the second position alignment portion 14b are fixed in the overlapping position, so that Fig. 9B The base end portion C1 and the tip end portion C2 of the Rogowski coil C shown are reliably located at the same position or substantially the same position.

[0105] The fixing may be welding, or wrapping with tape, or Fig.10 As shown, the front end portion 11 and the base end portion 12 of the main body portion 10 of the overlapped position alignment portion 14 are sandwiched by a housing H as a metal fixing member. Thus, when the current of the measurement object is measured, the base end portion C1 and the front end portion C2 of the Rogowski coil C (see FIG. 9 ) can be prevented from being displaced from the overlapped state. In addition, if the housing H is made of metal, it is possible to prevent external noise from mixing into the overlapped position.

[0106] In addition, using Fig.11A The housing H1 (fixing member) shown can also fix the base end portion C1 and the tip end portion C2 of the Rogowski coil C in an overlapping state.

[0107] The housing H1 is a square tube having an insertion hole H1a formed along the insertion direction of the main body 10. In the housing H1, the main body 10 extends through the inner wall of the insertion hole H1a toward the opening of the insertion hole H1a, and the base end 12 protrudes from the insertion hole H1a.

[0108] By inserting the distal end portion 11 into the insertion hole H1 a , the distal end portion 11 is overlapped with the proximal end portion 12 .

[0109] exist Fig.11AIn the example shown, a through hole 11a as a fitted portion is formed in the front end portion 11 of the main body 10. A convex portion H1b as a fitting portion is formed on the inner wall of the insertion hole H1a on the side of the front end portion 11.

[0110] like Fig. 11B As shown, the base end C1 and the tip end C2 of the Rogowski coil C overlap each other by inserting the tip end 11 of the main body 10 into the insertion hole H1a and fitting the convex portion H1b as the fitting portion into the through hole 11a as the fitted portion.

[0111] As described above, by using the through hole 11a as the engaged portion and the convex portion H1b as the engaging portion as the positioning portion, the base end C1 and the distal end C2 of the Rogowski coil C can be reliably overlapped, and the distal end 11 and the base end 12 of the main body 10 can be fixed in an overlapped state.

[0112] In addition, Fig.11A and Fig. 11B In the example shown, the base end portion 12 of the main body portion 10 penetrates the housing H1 from the beginning, but the main body portion 10 may be arranged in a state where the front end portion 11 penetrates and the base end portion 12 is inserted during measurement.

[0113] In addition, a recess may be provided in addition to the through hole 11a provided at the front end portion 11. In addition, a convex portion may be provided in place of the through hole 11a. When a convex portion is provided in place of the through hole 11a, the convex portion of the main body portion can be fitted into the concave portion of the housing H1 by providing the inner wall of the insertion hole H1a with a through hole or a recess.

[0114] Alternatively, Fig.11A and Fig. 11B As shown, the through hole 11 a and the convex portion H1 b are provided, and the end surface of the front end portion 11 of the Rogowski type current sensor 100 is brought into contact with the upper inner wall of the insertion hole H1 a of the fixture H1 to perform position alignment.

[0115] For example, Fig. 12A and Fig. 12B The housing H2 shown is formed with an insertion hole H2 a for being inserted into the front end portion 11 of the main body portion 10 so as to overlap with the base end portion 12 .

[0116] The insertion hole H2a is provided with a stopper H2b which, when the distal end portion 11 is inserted, blocks the insertion at a position where the base end portion and the distal end portion of the Rogowski coil overlap.

[0117] By forming the housing H2 in this manner, when the distal end portion 11 of the main body 10 is inserted into the insertion hole H2a of the housing H2, the insertion is blocked by the stopper H2b, and the base end portion and the distal end portion of the Rogowski coil are fixed in an overlapped state.

[0118] exist Fig. 12A and Fig. 12B In the housing H2 shown, the base end portion 12 of the main body portion 10 also penetrates the fixing member H2 from the beginning, but it can also be arranged in a state where the front end portion 11 penetrates and the base end portion 12 is inserted during measurement.

[0119] like Figure 2A As shown in FIG. 1 , when the main body 10 is bent into a ring shape to surround the wiring to be measured, the base end C1 and the tip end C2 of the Rogowski coil C can be overlapped by the positioning portion 14 (the first positioning portion 14a and the second positioning portion 14b). Therefore, the Rogowski type current sensor 100 can accurately output a signal corresponding to the current of the wiring from the Rogowski coil C.

[0120] In addition, the Rogowski current sensor 100 formed in this manner can be flexibly deformed repeatedly even if the main body 10 is bent into a ring shape because the main body 10 is formed of a flexible wiring substrate. In addition, since the strip-shaped flexible wiring substrate is formed thin, it can be inserted even in a narrow gap and wound around a measurement object such as a wiring.

[0121] Thus, the Rogowski current sensor 100 can be flexibly deformed and can be easily mounted even in a narrow gap.

[0122] Further, by making the base end 12 wider than other parts, subsequent connection work such as wiring to each pad can be facilitated. In addition, the shape makes it easy to distinguish whether it is the base end 12 side or the tip end 11 side, and the installation workability of the Rogowski current sensor 100 becomes good.

[0123] Even when the main body 10 is inserted into a narrow gap and bent, the front end portion 11 has the long hole 111 formed therein, so that the rigidity is reduced, and thus the front end portion 11 can be easily bent.

[0124] In addition, in the present embodiment, the long hole 111 is formed so that the front end portion 11 is easy to bend and the front end portion 11 is easy to be inserted into the gap of the wiring, etc., but it is not necessary to provide a through long hole 111, and the thickness of the portion corresponding to the long hole 111 can be made thinner than other portions (remove the shielding layer S to make it thinner) to improve the bending property, or a material more flexible than the flexible wiring substrate can be buried in the portion corresponding to the long hole 111. That is, since the operability of the front end portion 11 can be improved at the same time, it is preferable to provide a soft portion such as the long hole 111 on the side of the front end portion 11.

[0125] Furthermore, in the present embodiment, a long hole 111 (soft portion) is provided to improve the insertability of the front end portion 11 into a gap or the like, but depending on the design and use environment, the installation performance can be improved by making the front end portion 11 less likely to bend, and thus the portion corresponding to the long hole 111 may be thicker than other portions and less likely to bend, or a material (hard material) less flexible than the flexible wiring substrate may be embedded in the portion corresponding to the long hole 111.

[0126] As described above, by providing a flexible portion on (near) the tip end portion 11 , the bending ease of the tip end portion 11 can be adjusted, thereby achieving easy installation when assembled into modules or equipment in various environments.

[0127] In addition, the Rogowski coil C is sandwiched on both sides in the thickness direction by the shielding layer S. Therefore, when the current is measured using the Rogowski current sensor 100, no matter which side of the main body 10 faces the measurement object, the shielding layer S is interposed between the Rogowski coil C and the measurement object. Therefore, the shielding layer S can block the influence of the electric field generated by the measurement object.

[0128] Furthermore, since the shield layer S is formed of the mesh S1 intersecting the longitudinal direction F1, when the main body 10 is bent, the rigidity can be suppressed compared to the case where the metal wire extends along the longitudinal direction F1. Therefore, the force when the main body 10 is bent can be reduced.

[0129] In order to maximize the effect of the shielding layer S, it is preferred to provide the shielding layer S on the entire surface of both main surfaces (the first main surface and the second main surface) in a manner of sandwiching the Rogowski coil C as described above, but the shielding layer S may be provided locally depending on the use environment of the Rogowski type current sensor. That is, the shielding layer S may be provided only near the central portion of the main body 10, or the shielding layer S may be provided separately at both ends of the main body 10 instead of being provided at the central portion of the main body 10. In addition, the shielding layer S may be provided only on one main surface side instead of on both main surface sides. By providing the shielding layer S locally in this way, the characteristics can be improved compared to when there is no shielding layer S.

[0130] For example, the conventional Rogowski type current sensor described in Patent Document 1 is shown in Fig.13A .

[0131] Fig.13A The Rogowski coils of the Rogowski type current sensor shown are rectangular in shape and are formed on a plane S0 perpendicular to the closed line L. The coils 1 are connected by a forward line 2c parallel to the closed line L. If the number of the plurality of coils 1c is n turns, a return line 3c is provided along the closed line L from the winding end of the nth turn coil 1c starting from the first turn coil 1c to the winding start end of the first turn coil 1.

[0132] As described above, the coil 1c is formed on a plane S0 perpendicular to the closed line L, so the current flowing through the wire path inside the coil 1c is detected, but the current flowing outside the coil, such as Fig. 13B As shown, the noise can be reduced by setting the height d from the outbound line 2c to the return line 3c to be very small compared with the thickness t of the coil, so that its size can be ignored relative to the coil.

[0133] This effect can be obtained when the return line 3 is routed from the second side 1 b toward the outbound line 2 .

[0134] However, if the printed wiring board is thicker, Fig. 13B As shown, the height d of the outbound line 2c and the return line 3c can be simply set to be much smaller than the thickness t of the coil. However, in the case of a thin flexible wiring substrate, the thickness of the substrate is less than 300 μm, so it is difficult to ensure a sufficient height difference.

[0135] Therefore, if a conventional Rogowski coil is formed on a flexible wiring substrate, the magnetic flux passing through the plane Sc surrounded by the outgoing line 2c, the return line 3c and the height d will also be affected, and the normal vector of the plane Sc is perpendicular to the normal vector of the plane S0. Therefore, in the conventional Rogowski coil, the influence of the normal vector of the plane S0 and the normal vector of the plane Sc on the magnetic flux becomes a composite vector.

[0136] Therefore, in the Rogowski coil C involved in this embodiment, as shown in FIG. Fig.15 As shown, the through hole 1D is formed at a position offset from the through hole 1C in the arrangement direction of the coils 1 .

[0137] Specifically, when observing the flexible wiring substrate from the thickness surface of the main body 10 (flexible wiring substrate), the distance (coil spacing) between the through hole 1C (third side 1c) of the coil 1 and the through hole 1C (third side 1c) of the adjacent coil 1 is set to Wp, the offset of the other through hole 1D (fourth side 1d) relative to one of the through holes 1C (third side 1c) of the coil 1 is set to Ws, the height from the second coil pattern 1B (second side 1b) to the first coil pattern 1A (first side 1a) is set to T1, and the height from the return line 3 to the first coil pattern 1A (first side 1a) is set to T2.

[0138] At this time, in the Rogowski coil C, a relationship of 0<Ws<2×Wp×T2 / T1 is established, and in particular, in the present embodiment, a relationship of Ws×T1=Wp×T2 is established.

[0139] Thus, the influence of the normal vector of the plane Sp of Wp×T2 on the magnetic flux is cancelled by the normal vector of the plane Ss of Ws×T1. Therefore, the Rogowski current sensor 100 can reduce the generation of noise and accurately measure the current.

[0140] like Fig.16 As shown, if the offset Ws is greater than 0, a plane Sp is formed, a normal vector of the plane Sp is generated, and thus the influence of the magnetic flux passing through the plane Sp can be reduced.

[0141] In addition, when the offset amount Ws is equal to or larger than 2×Wp×T2 / T1, the area of ​​Ws×T1 becomes too large, and the influence on the magnetic flux becomes worse than when the offset amount Ws is 0.

[0142] Therefore, in order to reduce the adverse effect of the magnetic flux in the plane Sp of Wp×T2, the coil 1 is set to the relationship of 0<Ws<2×Wp×T2 / T1. This can achieve the effect of reducing noise.

[0143] Therefore, the Rogowski type current sensor can reduce the generation of noise, so the current can be measured accurately.

[0144] For example, Ws (reference FIG. 14A to FIG. 14C ) is set to 96.9 μm, Wp representing the distance between coils 1 (the distance between the fourth side 1d and the adjacent third side 1c as the coil pitch) is set to 420 μm, T1 is set to 162.5 μm, and T2 is set to 37.5 μm.

[0145] At this time, Ws×T1=96.9μm×162.3μm=15.7mm 2 , Wp×T2=420μm×37.5μm=15.7mm 2, so the relationship is Ws×T1=Wp×T2.

[0146] Therefore, the relationship of 2×Wp×T2 / T1 is 2×420 μm×37.5 μm / 162.5 μm, and the allowable offset amount Ws reaches 193.8 μm.

[0147] This can reduce the adverse effects of the magnetic flux on the plane Sp (Wp plane line) sandwiched between the forward line 2 and the return line 3 formed between the coil pitches.

[0148] However, since the through holes 1C and 1D corresponding to the third side and the fourth side are formed by drilling, errors may occur at this time.

[0149] For example, when the drilling interval error ε is set to 40 μm, if the allowable offset Ws reaches 193.8 μm, Ws may become 193.8 μm + 40 μm.

[0150] Therefore, if Fig.17 As shown, the maximum allowable value of Ws 2×Wp×T2 / T1 minus the spacing error ε can eliminate the errors during manufacturing and ensure accuracy. Therefore, the ideal situation is to set it to 0<Ws<2×Wp×T2 / T1-ε, and the maximum allowable amount of offset Ws can be set to 193.8μm-40μm.

[0151] In addition, if FIG. 14A to FIG. 14C As shown, to be precise, Wp and Ws can be set to the axis positions of the through holes 1C and 1D. Fig.15 As shown, T1 may be set as the distance between the axis of the first coil pattern 1A and the axis of the second coil pattern 1B. In addition, T2 may be set as the distance between the axis of the first coil pattern 1A and the axis of the return line 3.

[0152] In the Rogowski coil C, if Fig.14A As shown, the first coil pattern 1A is arranged along the closed line L (reference Figure 3 ) is formed in a direction orthogonal to the closed line L, and the outbound route 2 is formed parallel to the closed line L.

[0153] In addition, if Fig. 14C As shown, the second coil pattern 1B is formed into a crank shape in which a pair of patterns extending in directions perpendicular to the closed line L from both ends are connected by a pattern formed parallel to the closed line L.

[0154] Since the Rogowski coil C is formed in this way, Fig.18 As shown, when the Rogowski coil C is viewed from the thickness direction (from above), the plane of the coil 1 cannot be seen, so that the noise resistance can be improved.

[0155] In addition, the first layer is formed Figure 5A The first coil 1 (ref. Figure 3 ) connected to the connection pattern 123, and formed on the second layer Fig. 6A The connection pattern 123 connected to the return line 3 is formed at a position overlapping in the thickness direction. Therefore, when viewed in the thickness direction, the loop area can be reduced, so that the parasitic inductance can be reduced and the noise resistance can be improved.

[0156] In addition, in this embodiment, if Fig.18 As shown, in the Rogowski coil C, the first coil pattern 1A is formed in a direction perpendicular to the closed line L, the outbound line 2 is formed parallel to the closed line L, and the second coil pattern 1B is formed in a crank shape that connects a pair of patterns extending from both ends in a direction perpendicular to the closed line L using a pattern formed parallel to the closed line L.

[0157] However, it is sufficient that the through hole 1D is formed at a position offset from the through hole 1C in the arrangement direction of the coils. FIG. 19A to FIG. 19C As shown, the first coil pattern 1A and the second coil pattern 1B may be formed in a straight line.

[0158] In addition, in this embodiment, a structure in which through hole 1D is formed at a position offset from through hole 1C in the arrangement direction of coil 1 (hereinafter referred to as a characteristic improvement region) is used for the entire region of Rogowski coil C, and it is considered that this structure can most effectively improve the characteristics.

[0159] However, depending on the use environment, specifications, etc., the characteristic improvement area can also be applied to a part of the Rogowski coil C. That is, when the full length of the formed Rogowski coil C is set to 100%, it is preferred that the formation length of the area (characteristic improvement area) where the above-mentioned through hole 1D is formed at a position offset in the arrangement direction of the coil 1 relative to the through hole 1C is set to be 30% or more, preferably 70% or more, and more preferably 90% or more. If the characteristic improvement area is less than 30% of the full length of the Rogowski coil C, reliable characteristic improvement may not be obtained. In addition, the characteristic improvement area can also be continuously formed on a part of the Rogowski coil C, and the characteristic improvement area can also be dispersedly formed on the Rogowski coil C. That is, the characteristic improvement area and the non-characteristic improvement area can be alternately set.

[0160] Furthermore, the positioning portion 14 is a mark formed according to the conductive pattern, but may be, for example, a notch or a through hole formed in the flexible wiring substrate.

[0161] Furthermore, in the conventional Rogowski type current sensors described in Patent Documents 2 to 4, the Rogowski coil is formed by winding a conducting wire into a spiral shape, so there is a large manufacturing variation, and each product needs to be corrected using a corresponding analog circuit.

[0162] However, in the Rogowski type current sensor of the present embodiment, the Rogowski coil C is formed by the conductive pattern of the flexible wiring substrate (refer to Figure 2A ), so the Rogowski coil C can be accurately reproduced, thereby suppressing the deviation during manufacturing and eliminating the need to correct the characteristics.

[0163] Next, Figure 1A or Figure 1B An example in which the Rogowski type current sensor 100 is applied to an inverter will be described.

[0164] Fig. 20 The inverter IV shown converts direct current from the battery BT into alternating current to drive the three-phase alternating current motor MT.

[0165] In inverter IV, the first bridge arm A1 to the third bridge arm A3 of the three bridge arms that output current of each phase are connected in parallel between one power line from the battery BT (the power line P1 on the positive side of the battery BT) and the other power line (the ground line P2 on the negative side of the battery BT).

[0166] The first bridge arm A1 to the third bridge arm A3 are connected in series with upper bridge arms A11, A21, A31 and lower bridge arms A12, A22, A32.

[0167] The upper bridge arms A11 to A31 are connected to the power line P1 through the first wiring L1. The lower bridge arms A12 to A32 are connected to the ground line P2 through the second wiring L2. The upper bridge arms A11 to A31 and the lower bridge arms A12 to A32 are connected through the third wiring L3.

[0168] The upper bridge arms A11 to A31 and the lower bridge arms A12 to A32 are composed of switch elements and return diodes. The switch elements are formed by semiconductor devices. For example, the switch elements can use bipolar transistors, MOSFETs (metal-oxide-semiconductorfield-effect transistors), IGBTs (Insulated Gate Bipolar Transistors), etc. In particular, IGBTs that can flow large currents and have fast switching speeds are ideal.

[0169] The Rogowski current sensor 100 is mounted to surround two wirings, namely, a first wiring L1 between the power line P1 and the upper arms A11 to A31 and a second wiring L2 between the ground line P2 and the lower arms A12 to A32 .

[0170] There is provided a current measuring device 200 for measuring a current based on an output from the Rogowski current sensor 100. The current measuring device 200 includes current measuring circuits 201 to 203 for each phase.

[0171] The inverter IV includes a control unit (not shown) that controls switching of the upper arms A11 to A31 and the lower arms A12 to A32.

[0172] The control unit controls gate signals as switching signals of the first to third arms A1 to A3 based on signals from the current measuring device 200, and adjusts current values ​​and frequencies of output currents iu, iv, iw of the third wiring L3 from the arms A1 to A3.

[0173] In addition, the current measuring circuits 201 to 203 of the current measuring device 200 can detect excessive current flowing through the first bridge arm A1 to the third bridge arm A3 (upper bridge arms A11 to A31 and lower bridge arms A12 to A32) and generate an alarm.

[0174] In addition, a method of mounting the Rogowski current sensor 100 on a component will be described from another perspective.

[0175] The structure of the Rogowski type current sensor 100 is as described above, and its structure can be expressed as follows. Figure 1A or Figure 1B The main body 10 shown is a strip-shaped body as a whole and has flexibility, and is composed of a flexible wiring substrate, etc. The main body 10 is composed of a first main surface 1S, a second main surface 2S which is the opposite surface of the first main surface and has substantially the same width, and a pair of side surfaces 3S (thickness surfaces having a length corresponding to the thickness of the main body 10, and the widths of the first main surface 1S and the second main surface 2S are much larger than the width of the side surfaces 3S) provided between the first main surface 1S and the second main surface 2S.

[0176] The cross section of the main body 10 is generally rectangular. A Rogowski coil C (refer to Figure 2A ), a terminal portion (welding pad 121) electrically connected to the Rogowski coil C is provided at one end of the main body portion 10. In addition, a front end portion 11 to be subsequently connected to the vicinity of the terminal portion is provided on the opposite side where the terminal portion is provided.

[0177] The Rogowski current sensor 100 is installed in a ring shape, for example, so as to surround one or more terminals of a power semiconductor mounted on a module. That is, at this time, for example, the Rogowski current sensor 100 can be deformed into a ring shape so that the first main surface 1S is on the inside and the second main surface 2S is on the outside.

[0178] Conversely, the Rogowski current sensor 100 may be deformed into a ring shape with the second main surface 2S being the inner side and the first main surface 1S being the outer side. Then, the front end portion 11 is joined to the terminal portion or the vicinity of the terminal portion by bonding, abutting, riveting or other joining methods, and is mounted in the shape of a ring on a terminal line of a power semiconductor or the like.

[0179] By making the main body 10 a strip-shaped body with a rectangular cross section and installing it in a ring shape as described above, a specific portion of the Rogowski coil C, which is generally formed with a rectangular cross section, can be opposed to the terminal line side of the power semiconductor, etc., and characteristic deviation can be suppressed.

[0180] In addition, wiring is connected to the terminal portion in order to electrically connect other devices or components, or to connect to a cable via a connecting plug. In this case, before the Rogowski current sensor 100 is installed on the terminal wire of a power semiconductor or the like, the terminal portion may be installed in a ring shape with the wiring pre-connected to the terminal portion, or the terminal portion may be wired after the Rogowski current sensor 100 is installed on the terminal wire.

[0181] Such a Rogowski current sensor 100 is often mounted on a product that uses a high current, and is used to monitor the current during operation of the product, or to investigate, test, and measure characteristics of prototypes or defective products of a product that uses a high current.

[0182] In addition, if Fig.21 As shown, other embodiments are also conceivable. Fig.21 1 is a perspective view showing a state before the Rogowski current sensor 100 according to the present embodiment is attached to a current path to be measured.

[0183] exist Fig.21 In the figure, 300 and 301 are respectively connection parts of the measuring object for connecting to the current path of the measuring object, for example, electronic parts such as power semiconductors, or electrodes formed by wiring patterns formed on a substrate (not shown).

[0184] Reference numerals 302 to 304 are lead wires serving as a current path to be measured for connecting the connection parts 300 and 301 to be measured so as to provide electrical continuity between the connection parts 300 and 301 , and are made of a conductive material.

[0185] exist Fig.21In the embodiment, the connection parts 300 and 301 to be measured are electrically connected by three lead wires 302 to 304, but the connection can also be made by one, two, or even four or more lead wires.

[0186] Both end portions 30X of the lead wires 302 to 304 are connected to the measurement target connection portions 300 and 301 , and the middle portion 30Y is bent in a mountain shape to be formed in an arch shape.

[0187] Therefore, a closed area surrounded by the current path of the measurement object, namely the leads 302 to 304, the measurement object connection parts 300 and 301 connected to the two ends of the leads 302 to 304, and the substrate is formed, and a gap is formed between the middle part 30Y of the leads 302 to 304 and the substrate.

[0188] The first position alignment portion 14a formed at one side of the position alignment portion of the Rogowski type current sensor 100, i.e., the front end portion, is configured as a through hole. With this structure, the linear body 305 can be directly connected to the first position alignment portion 14a. In this case, for example, a ring-shaped connection portion 305a can be formed on the linear body 305. In this way, the linear body 305 can be connected to the first position alignment portion 14a, thereby allowing the linear body 305 to easily pass through the gap between the lead wires 302 to 304 and the measurement target connection portion 300, 301, which has a narrow gap, or between the lead wires 302 to 304 and the substrate on which the measurement target connection portion 300, 301 is mounted.

[0189] Then, if Fig. 22 As shown, the linear body 305 is pulled so that the linear body 305 passes entirely through the closed area until the main body 10 of the Rogowski current sensor 100 is located in the closed area formed by the lead wires 302 to 304 and other components.

[0190] Next, the Rogowski type current sensor 100 is bent and rolled around the lead wires 302 to 304 .

[0191] At this time, Figure 2A The Rogowski current sensor 100 is annularly mounted on the current path of the measurement object using the marking portion (positioning portion 14 (first position alignment portion 14a, second position alignment portion 14b)) formed on the Rogowski current sensor 100 as a reference. This facilitates accurate mounting and suppresses characteristic deviation.

[0192] Since the marking portion is the positioning portion 14, the base end and the tip end of the Rogowski coil C are overlapped by installing it on the current path of the measurement object based on the marking portion, so that the winding start end and the winding end end of the Rogowski coil C can be accurately overlapped.

[0193] In addition to using the marking portion as the positioning portion, the marking portion may also be used to shift the winding start end and the winding end end of the Rogowski coil C from the overlapping position as long as it can be formed into a ring shape.

[0194] In this way, when the Rogowski type current sensor 100 is wound around the lead wires 302 to 304, even if the lead wires 302 to 304 are joined to the connection parts 300 and 301 of the measurement object without any gap, making it impossible to insert the Rogowski type current sensor 100 from the side along the length direction, the Rogowski type current sensor 100 can be easily passed through a narrow gap formed by the current path of the measurement object and other components.

[0195] In addition, in the present embodiment, the marking portion is formed by a pad, but it can also be formed by providing a through hole in the Rogowski type current sensor, or by printing with ink or the like, or by independently forming it with the same material as the electrode when forming various electrodes.

[0196] In addition, since the lead wires 302 to 304 are joined to the connection parts 300 and 301 of the measurement object, there is no gap between the ends of the lead wires 302 to 304 and the connection parts 300 and 301 of the measurement object. However, the current path of the measurement object is in a non-contact state with other components, and even if there is a small gap, it is difficult to wind the Rogowski type current sensor 100. In this case, by installing the linear body 305 on the Rogowski type current sensor 100 so that the linear body 305 can pass through the small gap, the Rogowski type current sensor 100 can be wound on the current path of the measurement object.

[0197] In addition, although not shown in the figure, if one wishes to insert the Rogowski current sensor 100 into only one of the leads 302 to 304, for example, into the lead 302, the front end portion of the Rogowski current sensor 100 (the end portion on the first position alignment portion 14a side) must be passed through the narrow gap between the lead 302 and the lead 303 using the linear body 305.

[0198] However, by using the linear body 305 as in the present embodiment, the linear body 305 thinner than the Rogowski current sensor 100 can be passed between the lead wires 302 and 303 . Therefore, the linear body 305 can be easily passed through the narrow gap between the lead wires 302 and 303 , thereby improving the mountability.

[0199] The thread body 305 can be made of a flexible filament made of cotton, chemical fiber, etc., or made of a thinner metal or plastic, etc. In addition, as the thread body 305, a filament having a hook portion that is easily bent at the front end is preferably used.

[0200] Alternatively, silkworm silk used for fishing or the like may be used as the thread 305, and a hook-shaped metal member or a clip-shaped metal member may be attached to the front end thereof to indirectly attach the thread 305. Furthermore, the thread 305 may also be composed of a plurality of composite materials with a priority given to ease of use.

[0201] That is, although not shown in the figure, the connecting portion 305a side of the linear body 305 connected to the Rogowski type current sensor 100 can be formed using an easily deformable material such as Ceropegia silk, and a flat plate of a resin having a certain degree of flexibility can be connected to the front end of the linear body 305 using an adhesive or mechanically.

[0202] In addition, depending on the specifications, the linear body 305 formed of Cecropia silk may be indirectly connected to the Rogowski current sensor 100 via a resin flat plate or the like.

[0203] With this structure, when the Rogowski current sensor 100 is mounted, the linear body 305 can be combined with a plurality of appropriate materials according to the condition of the portion to be mounted.

[0204] exist Fig. 22 In the embodiment shown, the silkworm silk is tied to the first position alignment portion 14a, and the silkworm silk is inserted into a narrow gap such as between the lead wires 302 and 304, and the Rogowski type current sensor 100 is passed through the narrow gap by pulling the silkworm silk. Regarding setting the first position alignment portion 14a as a through hole, for example, the first position alignment portion 14a shown in FIG. 2 is formed by a pattern, but it can also be easily achieved by forming a through hole in the first position alignment portion 14a.

[0205] In addition, as another example, although it will slightly increase the time required for work, it is also possible to connect the linear body 305 to the end of the first position alignment portion 14a side by using an adhesive or the like without providing a through hole in the first position alignment portion 14a, as shown in FIG. Fig.21 and Fig. 22 At this time, it is preferable to select a material such as an adhesive so that the linear body 305 and the Rogowski type current sensor 100 can be easily peeled off with a force greater than a predetermined force.

[0206] Industrial Applicability

[0207] The present invention can be used as an ultra-small Rogowski type current sensor which is not easily affected by an external magnetic field and is easy to mass-produce and can be mounted on an inverter to detect abnormal current, or as a sensor connected to a meter for current measurement.

[0208] Description of Reference Numerals

[0209] 100: Rogowski type current sensor

[0210] 10: Body part

[0211] 10a: Frontend

[0212] 10b: base end

[0213] 11: Front end

[0214] 11a: Through hole

[0215] 111: Long hole

[0216] 12: Base end

[0217] 121: Soldering pad

[0218] 121a: First pad

[0219] 121b: Second pad

[0220] 123: Connection pattern

[0221] 13: Measurement Department

[0222] 14: Position alignment unit

[0223] 14a: First position alignment unit

[0224] 14b: Second position alignment section

[0225] 15a, 15b: Lamination

[0226] 15c: Through hole

[0227] 1.1c: Coil

[0228] 2.2c: Outbound route

[0229] 3.3c: Return line

[0230] 1A: First coil pattern

[0231] 1B: Second coil pattern

[0232] 1C, 1D: Through hole

[0233] 1C', 1D': One of the connecting parts

[0234] 1C", 1D": Another connection

[0235] C: Rogowski coil

[0236] C1: Base end

[0237] C2: Front end

[0238] L: closed line

[0239] Ws: offset

[0240] Wp: Coil spacing

[0241] T1, T2: Height

[0242] K1, K2: Interval

[0243] W: Wiring

[0244] F1: Length direction

[0245] S: Shielding layer

[0246] S1: Net

[0247] Ss, Sp, S0, Sc: plane

[0248] H, H1, H2: Shell

[0249] H1a, H2a: Insertion hole

[0250] H1b: convex part

[0251] H2b: Resistance

[0252] IV: Inverter

[0253] BT: Battery

[0254] MT: Three-phase AC motor

[0255] 200: Current measuring device

[0256] 201~203: Current measurement circuit

[0257] P1: Power cable

[0258] P2: Ground wire

[0259] A1: First bridge arm

[0260] A2: Second bridge arm

[0261] A3: The third bridge arm

[0262] A11~A31: Upper bridge arm

[0263] A12~A32: Lower bridge arm

[0264] L1: First wiring

[0265] L2: Second wiring

[0266] L3: Third wiring

[0267] 1S: First main surface

[0268] 2S: Second main surface

[0269] 3S: Side

[0270] 300, 301: Measurement object connection part

[0271] 302~304:lead

[0272] 30X: End

[0273] 30Y: Middle part

[0274] 305: Linear body

[0275] 305a: Connection part

Claims

1. A Rogowski type current sensor, comprising a main body, the main body being formed of a strip-shaped flexible wiring substrate and capable of surrounding a current path of a measurement object, and having a measurement portion having a Rogowski coil formed along a length direction according to a conductive pattern, in, In the Rogowski coil, each coil constituting the Rogowski coil forms a closed line along a current path surrounding the object to be measured, and between the winding end of one coil among the adjacent coils and the winding start end of the next coil, a plurality of coils are continuously connected by a forward line parallel to the closed line, and a return line parallel to the closed line is provided from the winding end of the last coil among the plurality of coils to the winding start end side of the first coil, The coil is formed by a first side having a winding end of the coil and a winding start end of the next coil, a second side located on the opposite side of the first side, a third side and a fourth side connecting both ends of the first side and the second side. Either the third side or the fourth side is formed on a plane including the other side and at a position offset from a plane orthogonal to the closed line. If the value representing the coil spacing between the coils is set to Wp, the value representing the offset between the third side and the fourth side is set to Ws, the value representing the height from the second side to the first side is set to T1, and the value representing the height from the return line to the first side is set to T2, then the relationship is 0<Ws<2×Wp×T2 / T1.

2. The Rogowski type current sensor according to claim 1, wherein: The main body has a base end portion which is provided at one end portion of the measuring portion and is wider than the measuring portion.

3. The Rogowski type current sensor according to claim 1, wherein: The main body is formed with a positioning portion that enables the base end portion and the tip end portion of the Rogowski coil to overlap when surrounding a current path of the measurement object.

4. The Rogowski type current sensor according to claim 1, wherein: A grid-like mesh formed according to a conductive pattern and intersecting the longitudinal direction is formed on a pair of layers sandwiching the Rogowski coil.

5. The Rogowski type current sensor according to claim 1, wherein: A soft portion is formed along the longitudinal direction of the main body at a front end portion of the main body, that is, a portion forward of the measuring portion.

6. The Rogowski type current sensor according to claim 1, wherein: The flexible wiring substrate has at least three conductive pattern layers. Each coil is formed by a first coil pattern formed on a first layer and serving as the outbound path and the first side connected to the outbound path, a second coil pattern formed on a third layer and serving as the second side parallel to the first coil pattern, and a pair of through holes serving as the third side and the fourth side connecting respective ends of the first coil pattern and the second coil pattern to each other. The outbound line is formed on a second layer between two layers consisting of the first layer and the third layer.

7. The Rogowski type current sensor according to claim 1, wherein: The offset amount Ws and the coil pitch Wp are in a relationship of Ws×T1=Wp×T2.

8. The Rogowski type current sensor according to claim 1, wherein: The main body has a signal extraction pad formed at the base end. The connection pattern connected to the first coil and the connection pattern connected to the return line are formed at positions overlapping in the thickness direction.

9. The Rogowski type current sensor according to claim 6, wherein: The first coil pattern is formed in a direction orthogonal to the closed line, The return line is formed in parallel with the closed line, The second coil pattern is formed in a crank shape by connecting a pair of patterns extending from both ends in a direction perpendicular to the closed line using a pattern formed in parallel with the closed line.

10. The Rogowski type current sensor according to claim 1, wherein: The main body surrounds the current path of the measured object, so that when the base end and the front end of the Rogowski coil are opposite to each other, the base end and the front end of the Rogowski coil are not in contact with each other, and the base end and the front end of the Rogowski coil are formed at the same position or at a position close to each other.

11. The Rogowski type current sensor according to claim 10, wherein: The distance in the thickness direction when the base end portion and the tip end portion of the Rogowski coil are opposed to each other is 1 mm or less.

12. The Rogowski type current sensor according to claim 10, wherein: The distance in the length direction when the base end portion and the tip end portion of the Rogowski coil face each other is set to be ±1 mm or less.

13. The Rogowski type current sensor according to claim 2, wherein: The Rogowski type current sensor includes a fixing member that fixes the base end portion and the tip end portion of the Rogowski coil in an overlapping state when the fixing member surrounds a current path of a measurement object via the main body portion.

14. The Rogowski type current sensor according to claim 13, wherein: In the main body, a fitting portion consisting of a recess, a through hole or a protrusion is formed on any one of the base end portion or the front end portion of the main body. The fixing member is formed with an insertion hole that can overlap with the other by inserting the one, On the inner wall of the insertion hole, a convex portion is formed to be fitted with the concave portion or the through hole of the fitted portion, or a fitting portion is formed of a concave portion or the through hole to be fitted with the convex portion of the fitted portion. When the fitting portion is fitted into the fitted portion, the base end portion and the tip end portion of the Rogowski coil overlap.

15. The Rogowski type current sensor according to claim 13, wherein: The fixing member is formed with an insertion hole which can overlap with the other by inserting either the base end portion or the front end portion of the main body portion. A stopper is formed in the insertion hole, and the stopper blocks the insertion at a position where the base end portion and the front end portion of the Rogowski coil overlap when the one is inserted.

16. An inverter comprising a Rogowski type current sensor according to claim 1, and a current measuring circuit, wherein the current measuring circuit measures the current flowing in the current path by using the output of the Rogowski type current sensor wound around any one or both of an upper bridge arm or a lower bridge arm connected in series between one power line and another power line from a power source as a current path.

17. A method for mounting a Rogowski type current sensor as claimed in claim 1, in, The Rogowski type current sensor is arranged on a current path of a measurement object; The strip-shaped flexible main body of the Rogowski current sensor has a first main surface, a second main surface opposite to the first main surface, and a pair of side surfaces, and The Rogowski coil is embedded in the main body and has a base end portion provided at one end portion of the measuring portion and wider than the measuring portion; The method includes mounting the Rogowski current sensor on a current path of a measurement target so as to surround the current path of the measurement target and to place one of the first main surface or the second main surface inside.

18. The method for installing a Rogowski type current sensor according to claim 17, wherein: A linear body is directly or indirectly connected to one end of the Rogowski current sensor, and after the linear body is inserted into a gap between the current path of the measurement object and other components, the Rogowski current sensor is wound around and installed on the current path of the measurement object by moving the linear body.

19. A method for installing a Rogowski type current sensor as claimed in claim 1, wherein: In the Rogowski type current sensor, the Rogowski coil has a base end portion provided at one end portion of the measuring portion and wider than the measuring portion. The method includes installing the Rogowski type current sensor around a current path of a measurement object using marking portions formed at both ends of the Rogowski type current sensor as a reference.

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