JP2009222696A - Multiphase current detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: a conventional current sensor having primary conductors formed in a U-shaped configuration has the advantage of removing a uniform external field being applied a reverse direction magnetic field to each of left and right half bridge circuits of a bridge circuit, but it is targeted only for a single phase measurement, and it is not configured to detect multiphase currents more accurately by decreasing the influence of other phase currents. <P>SOLUTION: A part, which becomes a non U-shaped part, of the primary conductor located out of a U-shaped part extends toward the out of plane direction of the U-shaped part, and the symmetric axes of the U-shaped parts adjacent to respective U-shaped parts are arranged in parallel in the same plane so as not to exist on the same straight line. Therefore, when detecting the multiphase currents, the influence of magnetic fields generated by the other phase currents is decreased, and the effect of detecting the more accurate currents can be expected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multi-phase current detection device for detecting a current to be measured applied to each phase in the vicinity of each U-shaped forming portion in which a multi-phase is formed by a plurality of primary conductors having U-shaped forming portions. Is.

  As a conventional current sensor or current detection device, there is one in which a bridge circuit formed of a plurality of magnetoresistive elements is arranged in the vicinity of a U-shaped primary conductor (see, for example, Patent Document 1).

  Also, as a multiphase current detection device, each surface mount type current sensor is arranged in the center of each detected current path bent at a right angle in a crank shape twice, and each detected current path is aligned. Yes (see, for example, Patent Document 2).

  Furthermore, as another multiphase current detection device, each magnetoelectric conversion element is arranged in the vicinity of a bent portion of each conductor to be measured having a bent portion bent in a crank shape so that the bent portions do not overlap each other. There is one in which conductors to be measured are arranged substantially in parallel (see, for example, FIG. 6 of Patent Document 3).

  Japanese Patent Laid-Open No. 8-21138   JP-A-2005-233692   JP 2001-74783 A

  The primary conductor of the current sensor or the current detection device disclosed in Patent Document 1 has a symmetrical U-shaped structure, and a reverse magnetic field is applied to each of the left and right half bridges of a bridge circuit formed of magnetoresistive elements. It has the advantage of being applied and removing a uniform external magnetic field. However, the measurement of only a single phase is assumed, and there is a problem that the configuration for reducing the influence of the other-phase current and detecting the multi-phase current more accurately is not shown.

  In Patent Document 2, when a multiphase current is measured using a surface-mount current sensor, the surface-mount current sensor that detects a current of a certain phase is affected by a magnetic field generated by the current of another phase. Basically, it is configured to detect a multiphase current without receiving it. However, strictly speaking, the leakage magnetic field from the detected current path of the other phase is applied in the direction of the magnetic sensing of the surface mount type current sensor, so detection errors occur when each phase is placed close together. There was a problem to do. Furthermore, as shown in Patent Document 1, it is composed of a current sensor using a primary conductor having a U-shaped portion in which a reverse magnetic field is applied to the left and right half bridges of a bridge circuit composed of magnetoresistive elements. However, there is a problem that the detection error due to the external magnetic field increases because the uniform external magnetic field is not removed.

  Further, in Patent Document 3, each magnetoelectric conversion element is arranged in the vicinity of a bent portion of each measured conductor having a bent portion bent in a crank shape, and the measured conductors are substantially parallel so that the bent portions do not overlap. Due to the arrangement, the multiphase current can be detected without being affected by the magnetic field generated by the current of the other phase. However, even if each magnetoelectric conversion element is installed on the same substrate, there is a problem that the substrate becomes larger and the detection device becomes larger accordingly. Furthermore, as shown in Patent Document 1, it is composed of a current sensor using a primary conductor having a U-shaped portion in which a reverse magnetic field is applied to the left and right half bridges of a bridge circuit composed of magnetoresistive elements. In addition, there is a problem that detection errors due to the external magnetic field increase because the uniform external magnetic field is not removed.

  The present invention has been made to solve the above-described problems. In addition to removing a uniform external magnetic field, the influence of other-phase currents can be reduced when detecting multi-phase currents, and more accurate currents can be detected. Another object of the present invention is to obtain a small-sized and low-cost multiphase current detection device.

  In the multiphase current detection device according to the present invention, the first half-bridge circuit is arranged in one region separated from the center line of the installation board by four magnetoresistive elements on the installation board. Each of the current detection device portion having the second half bridge circuit disposed in the other region and a plurality of primary conductors having at least one U-shaped formation portion. In the vicinity of the U-shaped portion, the center line of the installation board and the symmetry axis of the U-shaped portion are substantially aligned, and the primary conductor outside the U-shaped portion, which is a non-U-shaped portion, is U-shaped. It extends in the out-of-plane direction, and is arranged in parallel in the same plane so that the symmetry axes of the respective U-shaped forming portions are not on the same straight line.

As described above, according to the present invention, the first half-bridge circuit is arranged in one region divided with respect to the center line of the installation board by four magnetoresistive elements on the installation board, Since the second half bridge circuit is arranged in the other region and a magnetic field in the opposite direction is applied to each half bridge circuit, there is an effect of removing a uniform external magnetic field.
In addition, since each primary conductor is arranged in parallel in the same plane so that the symmetry axis of each U-shaped portion is not on the same straight line, the influence of the magnetic field generated by the current of the other phase when detecting the multiphase current And more accurate current detection.
Furthermore, since the non-U-shaped forming portion that forms the primary conductor together with the U-shaped forming portion has a structure that extends in the out-of-plane direction of the U-shaped forming portion, it can support multiple phases with at least one small sensor substrate, The apparatus is reduced in size, and the manufacturing process is simplified and the cost is reduced.

Embodiment 1 FIG.
1 is a perspective view of a multiphase current detection apparatus 1 according to Embodiment 1 of the present invention. FIG. 2 is a plan view (XY plane) of a current sensor for one phase of FIG. 1, and FIG. 2 is a cross-sectional view showing a part of an AA cross section (XZ plane) in FIG. The multiphase current detection device 1 shown in the figure is an example in which each phase current is detected by a current sensor installed for each phase in, for example, a three-phase AC current. The sensor substrate 3 having the detection device unit 7 and the sensor circuit unit 8 and the primary conductor 4 are configured, and the primary conductor 4 is configured by a U-shaped forming unit 5 and a non-U-shaped forming unit 6. In the figure, the non-U-shaped portion 6 of the primary conductor 4 is shown only in the vicinity of the current sensor 2 for simplicity, but is actually extended and connected to a power source, various devices, and the like.
In the first embodiment, each primary conductor 4 is bent in the Z direction which is substantially perpendicular to the plane of the U-shaped portion 5 to form a non-U-shaped portion 6, thereby forming a U-shape. One current detection device unit 7 is arranged in the device installation unit 11 in the vicinity of the unit 5.
First, the configuration of the current detection device unit 7 will be described.
FIG. 5 shows a plan view of the current detection device unit 7, which is divided into two areas on the installation board 16 by the center line 10 of the installation board 16, and the magnetoresistive effect elements 13 a and 13 b, magnetic Resistive effect elements 13c and 13d are arranged equally in line symmetry. Here, the magnetosensitive direction of the magnetoresistive element 13 is the X direction. The four magnetoresistive effect elements 13a to 13d are arranged in parallel to each other with respect to the center line 10 of the installation substrate 16, and the magnetoresistive effect elements 13a and 13d have a resistance value corresponding to an increase in the magnetic field in the opposite direction. The magnetoresistive effect elements 13b and 13c have a magnetoresistive effect characteristic in which the resistance value decreases together with an increase in the magnetic field in the opposite direction. Although omitted in FIG. 2, a barber pole electrode structure is formed on the magnetoresistive element. The four magnetoresistive effect elements 13 are each configured as one, but a plurality of magnetoresistive effect elements may be connected in a crank shape to increase the line length. Further, it may be configured symmetrically with respect to the center point on the center line 10. The connection current line 14 forms a bridge circuit 17 by connecting the four magnetoresistive effect elements 13, and the connection area 15 is used as an input / output terminal portion of the bridge circuit 17.

FIG. 6 is a schematic configuration diagram showing the current detection device unit 7 of the current sensor 2 for one phase according to the first embodiment of the present invention. In FIG. By connecting, a half bridge circuit (first half bridge circuit) 18a composed of series connection of magnetoresistive effect elements 13a, 13b and a half bridge circuit (second second circuit composed of series connection of magnetoresistive effect elements 13c, 13d) A bridge circuit 17 comprising a parallel connection with a half bridge circuit) 18b is configured.
The connection area (first connection area) 15a is connected to the connection current line 14 between the magnetoresistance effect elements 13a and 13c of the bridge circuit 17, and the other connection area (second connection area) 15b is the bridge circuit. 17 is connected to a connection current line 14 between the magnetoresistive effect elements 13b and 13d, and a voltage is supplied to the bridge circuit 17 from the connection areas 15a and 15b. The connection area (third connection area) 15c is connected to the connection current line 14 between the magnetoresistive effect elements 13a and 13b of the bridge circuit 17, and the other connection area (fourth connection area) 15d is the bridge circuit. 17 is connected to the connection current line 14 between the magnetoresistive effect elements 13c and 13d, and the output voltage of the bridge circuit 17 is detected from the connection areas 15c and 15d.

  Although not shown in FIGS. 5 and 6, the compensation conductive line 19 is disposed above or below the four magnetoresistive elements 13 a to 13 d on the installation substrate 16, or both through an insulating layer. A magnetic compensation type configuration may be employed in which a current that cancels out the magnetic field generated in the vicinity of the four magnetoresistive effect elements 13 is supplied to the compensation conductive lines 19 based on the output voltage of the bridge circuit 17.

Next, the overall configuration of the current sensor 2 for one phase will be described.
As shown in FIG. 1, one U-shaped forming portion 5 is formed on a part of each primary conductor 4 to which a current to be measured is applied so as to have a U-shape when viewed from the Z direction. In the figure shown in the first embodiment, both side portions of the U-shaped bottom are formed in a right-angle shape, but the current detection device unit 7 is stably reversed from both sides of the U-shaped forming unit 5. However, the shape is not limited to this, and is not limited to this. In order to stably apply a magnetic field in the reverse direction, the U-shape is at least the current detection device unit 7. It is desirable that the image is symmetrical in the vicinity of.
As shown in FIG. 2, the sensor substrate 3 is installed on the upper side of the U-shaped forming part 5 so that the symmetry axis of the U-shaped forming part 5 and the center line 10 of the current detection device part 7 substantially coincide. In the present embodiment, an example in which the sensor substrate 3 is installed on the upper side of the U-shaped forming portion 5 has been shown. However, the installation position is not limited to the upper side, but is installed on the lower side, that is, the front side in FIG. May be. However, in order to support multiphase detection with one sensor substrate, it is desirable to fix the installation position on either side.
The installation position (especially in the Z direction) of the current detection device unit 7 is determined according to the magnetic field to be applied to the magnetoresistive effect element 13, that is, the magnitude of the current to be measured, but the U-shape of the primary conductor 4 in the Z direction. Since the applied magnetic field in the magnetosensitive direction is 0 at the center position of the forming portion 5 (broken line O in FIG. 3), it is preferable to displace it from the center. In the present embodiment, the example in which the current detection device unit 7 is installed above the U-shaped forming unit 5 via the sensor substrate 3 is shown, but the present invention is not limited to this. In addition, it may be placed inside the primary conductor 4 surrounded by the U-shaped portion 5. In particular, the cross-sectional area of the U-shaped portion 5 in the primary conductor 4 is determined according to the magnitude of the measured current value to be applied. Such a primary conductor 4 is produced, for example, by bending or casting from a linear conductor bar shape using a metal such as copper.
On the sensor substrate 3, the sensor circuit unit 8 is arranged together with the current detection device unit 7. The sensor circuit unit 8 supplies the voltage of the bridge circuit 17 to the connection areas 15a and 15b of the current detection device unit 7 and outputs the output voltage of the bridge circuit 17 with appropriate amplification. An external terminal 9 is used for input / output to / from. By completing all of these with a single sensor substrate 3, the manufacturing process can be simplified, and the cost and size can be reduced.
The sensor substrate 3 and the primary conductor 4 are fixed using an adhesive, a mounting member or the like, although not particularly shown. The mounting member is not particularly limited in material, but is preferably non-magnetic and less deteriorated with time, and may be entirely or partially resin-molded in order to increase the effect of insulation and pressure resistance.

Next, the operation of the current sensor 2 will be described with reference to FIGS. 3, 4, and 5.
When a current to be measured is applied to the primary conductor 4, for example, the first U-shaped portion 5aa has a right-rotating magnetic field as shown by a broken line in FIG. In 5ab, a left-rotating magnetic field is generated according to the magnitude of the current to be measured as shown by the broken line in FIG. For the sake of simplicity, the generated magnetic field is shown by one magnetic flux line for each primary conductor. As a result, when the current detection device portion 7 is installed on the upper side of the U-shaped portion shown in FIG. 3, the magnetoresistive effect elements 13c and 13d located on the right side of the current detection device portion 7 have a magnetic field shown in FIG. The vector 12 is applied, and the decomposition vector 12a is added in the magnetosensitive direction (X-axis direction) of the magnetoresistive effect elements 13c and 13d. That is, a magnetic field is applied to the magnetoresistive effect elements 13a and 13b shown in FIG. 5 on the XY plane of the current detection device unit 7 in the direction of the left side of the drawing with respect to the center line 10, and the magnetoresistive effect elements 13c and 13d have A magnetic field is applied in the direction of the right side of the drawing from the center line 10.

The magnetoresistive elements 13a and 13d both have a magnetoresistive effect characteristic in which the resistance value increases as the magnetic field increases and the resistance value decreases as the magnetic field decreases. In contrast, the elements 13b and 13c are configured to have a magnetoresistive effect characteristic in which the resistance value decreases as the magnetic field increases and the resistance value increases as the magnetic field decreases.
Therefore, as the current flowing through the primary conductor 4 increases, the resistance values of the magnetoresistive elements 13a and 13d increase, and the resistance values of the magnetoresistive elements 13b and 13c decrease, and the current flowing through the primary conductor 4 decreases. Accordingly, the resistance values of the magnetoresistive elements 13a and 13d decrease and the resistance values of the magnetoresistive elements 13b and 13c increase. In this way, the balance of the bridge circuit 17 is lost in accordance with the magnitude of the current to be measured applied to the primary conductor 4, and this becomes the output of the bridge circuit 17 of the current detection device unit 7.

Further, the operation of the current sensor 2 will be described in the case where the compensation conductive line 19 is provided. FIG. 7 shows a schematic configuration of the current detection device unit 7 and the sensor circuit unit 8 in which the compensation conductive wire 19 is arranged.
The balance of the bridge circuit 17 is lost depending on the magnitude of the current to be measured applied to the primary conductor 4. At this time, in the amplification circuit unit (for example, the operational amplifier 20) installed in the sensor circuit unit 8, based on the output voltage detected from the connection areas 15c and 15d of the current detection device unit 7, the vicinity of the magnetoresistive effect elements 13a to 13d A current (control current) that cancels the generated magnetic field is supplied to the compensation conductive line 19. Specifically, the magnitude of the control current is adjusted so that the output voltage of the connection areas 15c and 15d becomes zero. The compensating conductive line 19 cancels out the magnetic field generated in the vicinity of the four magnetoresistive elements 13a to 13d according to the magnitude of the control current, that is, the magnetic field according to the magnitude of the current to be measured applied to the primary conductor 4. Generate a magnetic field.
Therefore, the balance failure of the bridge circuit 17 according to the magnitude of the current to be measured applied to the primary conductor 4 can be repaired by the control current supplied from the sensor circuit unit 8. Therefore, the magnitude of the control current supplied from the sensor circuit unit 8 can be detected as a value correlated with the magnitude of the current to be measured applied to the primary conductor 4.
The external magnetic field (disturbance magnetic field) generated outside the primary conductor 4 has an in-phase influence on the magnetoresistive effect elements 13a and 13b and the magnetoresistive effect elements 13c and 13d (the left and right half bridge circuits 18 of the bridge circuit 17). Therefore, it is offset and does not affect the measurement accuracy.

Next, the installation configuration of each primary conductor 4a, 4b, 4c will be described. FIG. 8 is a plan view (XY plane) of the primary conductors 4a, 4b, and 4c of the multiphase current detection device 1 according to the first embodiment, and the U-shaped forming portions 5a, 5b, and 5c are in the XY plane. They are arranged in parallel and arranged so that the symmetry axes 21 of the adjacent U-shaped forming portions are not on the same straight line. FIG. 9 is a comparative example of a multiphase current detection device different from the first embodiment, in which U-shaped forming portions 5a, 5b, and 5c are arranged in parallel in the XY plane, and the symmetry of adjacent U-shaped forming portions is symmetrical. It arrange | positions so that the axis | shaft 21 may exist on the same straight line. FIG. 10 shows a modification of the multiphase current detection device 1 according to the first embodiment, in which the U-shaped forming portions 5a, 5b, and 5c are arranged in the XY plane, and the symmetry axis 21 of the adjacent U-shaped forming portion. Are arranged on the same straight line. FIG. 11 shows still another modified example of the multiphase current detection device 1 according to the first embodiment, in which the U-shaped forming portions 5a, 5b, and 5c are arranged in the XY plane and the U-shaped forming portions are symmetrical. It arrange | positions so that the axis | shaft 21 may not be on the same straight line.
When a current to be measured is applied to each primary conductor 4a, 4b, 4c, the magnetic field generated in the U-shaped forming portions 5a, 5b, 5c and involved in current detection is the X-direction magnetic field 22, which is shown in FIGS. As indicated by the arrow, the direction is the X direction on the XY plane. The X-direction magnetic field 22 applies a magnetic field in the opposite direction to each half bridge circuit of a magnetoresistive effect element (not shown in the figure) installed on the sensor substrate 3. A magnetic field or an external magnetic field generated in a portion other than this is applied as a uniform magnetic field to each half-bridge circuit of the magnetoresistive effect element, so that it is canceled and is not detected as an error. However, when a magnetic field in the opposite direction is applied to each half bridge circuit of the magnetoresistive effect element as an external magnetic field, it is detected as an error. In the installation configuration shown in FIG. 9, the leakage magnetic field caused by the X-direction magnetic field 22 generated in the adjacent other phase acts on each half bridge circuit of the magnetoresistive effect element as a magnetic field in the opposite direction. It will be superimposed as an error. Therefore, as shown in FIG. 8, FIG. 10, and FIG. 11, in order to reduce the influence from the X-direction magnetic field 22 generated in the adjacent U-shaped forming portion of the other phase, the symmetry axis of the adjacent U-shaped forming portion is If the primary conductors are placed apart from each other so that they are not on the same straight line, errors due to currents in other phases can be reduced. In the configuration example shown, the configuration shown in FIG. 8 is most advantageous for downsizing.
In the present embodiment, an example of detecting the current of a three-phase alternating current has been described. However, the present invention is not limited to three phases, and a plurality of primary conductors may be installed in a plurality of phases. 8, 10, and 11, the U-shaped portions 5 a, 5 b, and 5 c are arranged in parallel in the XY plane, but may be outside the XY plane.

  As described above, according to the first embodiment, the first half-bridge circuit is arranged in one region divided with respect to the center line of the installation board by four magnetoresistive elements on the installation board. In addition, the second half-bridge circuit is arranged in the other region, and a magnetic field in the opposite direction is applied to each half-bridge circuit in the magnetosensitive direction, so that a uniform external magnetic field can be removed. .

  In addition, the symmetrical axis of the adjacent U-shaped forming portion is set so that the magnetic field in the opposite direction is not applied from the primary conductor of the other phase to each half-bridge circuit of the magnetoresistive effect element portion serving as the magnetic field detecting portion. Since the symmetrical axes are separated so as not to be on the same straight line, the effect of the magnetic field due to the current of the other phase is not superimposed as an error, and the measurement accuracy is improved.

  Furthermore, since the U-shaped forming portions of the primary conductor can be installed side by side, a single small sensor substrate can support multiple phases, and all current detection device portions and sensor circuit portions can be provided on a single sensor substrate. Therefore, the manufacturing process can be simplified, the cost can be reduced, and the size can be reduced.

Embodiment 2. FIG.
FIG. 12 is a plan view (XY plane) of the primary conductors 4a, 4b, 4c and the sensor substrate 3 of the multiphase current detection apparatus 1 according to Embodiment 2 of the present invention. FIG. 13 is a side view of FIG. It is a figure (YZ surface). In the second embodiment, the U-shaped portions 5a, 5b, and 5c of the primary conductors 4a, 4b, and 4c are in the same plane, and the U-shaped portions 5 that are adjacent to the primary conductors. Are not on the same plane, and the primary conductors 4a, 4b, and 4c are installed so as not to overlap in the Z direction.
In the second embodiment, the arrangement of the primary conductors 4a, 4b, 4c and the sensor substrate 3 is changed from that of the first embodiment, and the overlapping parts are omitted in the configuration as other current sensors. In the first embodiment, the U-shaped portions 5a, 5b, and 5c of the primary conductors 4a, 4b, and 4c are installed in parallel in the XY plane. However, in the second embodiment, the primary conductors 4a and 4b are arranged in parallel. 4c U-shaped forming portions 5a, 5b, 5c have a symmetry axis 21 in the same plane, and the U-shaped forming portions 5a, 5b, 5c of the primary conductors 4a, 4b, 4c are shifted and installed outside the XY plane. It is a thing.

The overall configuration of multiphase current detection apparatus 1 in the second embodiment will be described.
The U-shaped forming portions 5a, 5b, and 5c of the three primary conductors 4a, 4b, and 4c corresponding to each phase have the same symmetry axes 21 in the XY plan view as seen from the Z-axis direction as shown in FIG. As shown in FIG. 13, the Y-axis side view is arranged so as to be shifted in the Z direction outside the XY plane, and the symmetry axis 21 of the U-shaped portion is configured to be in the same plane. In the first embodiment, the sensor substrate 3 may be installed on either the upper surface or the lower surface of each U-shaped forming portion 5a, 5b, 5c, but in the second embodiment, as shown in FIG. In addition, it is desirable to install the sensor substrate 3 at a position which is the lower surface of the U-shaped forming portions 5a and 5c and the upper surface of the U-shaped forming portion 5b. It becomes possible to cope with.
When a current to be measured is applied to each primary conductor 4a, 4b, 4c, the magnetic field generated in the U-shaped forming portions 5a, 5b, 5c and involved in current detection is the X-direction magnetic field 22, and is indicated by an arrow in FIG. Thus, the X direction is in the XY plane. The X-direction magnetic field 22 applies a magnetic field in the opposite direction to each half bridge circuit of a magnetoresistive effect element (not shown in the figure) installed on the sensor substrate 3. A magnetic field or an external magnetic field generated in a portion other than this is applied as a uniform magnetic field to each half-bridge circuit of the magnetoresistive effect element, so that it is canceled and is not detected as an error. However, when a magnetic field in the opposite direction is applied to each half bridge circuit of the magnetoresistive effect element as an external magnetic field, it is detected as an error. In the installation configuration shown in FIG. 9, the leakage magnetic field caused by the X-direction magnetic field 22 generated in the adjacent other phase acts on each half bridge circuit of the magnetoresistive effect element as a magnetic field in the opposite direction. Overlaid as an error. In order to reduce the influence from the X-direction magnetic field 22 generated in the adjacent U-shaped portion of the other phase, as shown in FIGS. 12 and 13, the symmetry axis of the adjacent U-shaped portion is in the same plane. If the primary conductors are installed so that adjacent U-shaped portions are not in the same plane and do not overlap in the Z direction, errors due to currents in other phases can be reduced.
In the present embodiment, an example of detecting the current of a three-phase alternating current has been described. However, the present invention is not limited to three phases, and a plurality of primary conductors may be installed in a plurality of phases. Moreover, in this Embodiment, although the example which shifted the U-shaped formation part 5b to the negative side of the Z direction was shown, you may shift and install in the positive side. In that case, it is desirable that the sensor substrate 3 is installed at a position that becomes the upper surface of the U-shaped portions 5a and 5c and the lower surface of the U-shaped portion 5b.

  As described above, according to the second embodiment, the magnetic field in the opposite direction is not applied from the primary conductor of the other phase to each half bridge circuit of the magnetoresistive effect element serving as the magnetic field detector. Due to the configuration in which the primary conductors are installed so that the symmetry axes of the adjacent U-shaped portions are in the same plane and the adjacent U-shaped portions are not in the same plane and do not overlap in the Z direction, The effect of the magnetic field due to the current is not superimposed as an error, and the measurement accuracy is improved.

  In addition, because the U-shaped forming portions of the primary conductor can be installed vertically, it is possible to handle multiple phases with a single small sensor substrate, and all current detection device portions and sensor circuit portions on one sensor substrate. Therefore, the manufacturing process can be simplified, the cost can be reduced, and the size can be reduced.

Embodiment 3 FIG.
FIG. 14 is a perspective view of the multiphase current detection apparatus 1 according to Embodiment 1 of the present invention, and FIG. 15 is a cross-sectional view (XZ plane) showing a part of the current sensor for one phase of FIG. 16 is a diagram showing an example of a magnetic field vector and a decomposition vector near one side (right side) of the current detection device unit 7 in FIG. The multiphase current detection device 1 shown in the figure is an example in which each phase current is detected by a current sensor installed for each phase in, for example, a three-phase AC current. The sensor substrate 3 having the detection device unit 7 and the sensor circuit unit 8 and the primary conductor 4 are configured, and the primary conductor 4 is configured by a U-shaped forming unit 5 and a non-U-shaped forming unit 6. In the figure, the non-U-shaped portion 6 of the primary conductor 4 is shown only in the vicinity of the current sensor 2 for simplicity, but is actually extended and connected to a power source, various devices, and the like.
In the third embodiment, each primary conductor 4 is bent in the Z direction, which is substantially perpendicular to the surface of the U-shaped portion 5, and the current flowing through the U-shaped portion 5 in the adjacent phase is measured. A non-U-shaped forming part 6 is formed so as to extend in the opposite direction, and one current detection device part 7 is arranged in a device setting part 11 in the vicinity of the U-shaped forming part 5.
In the third embodiment, the extension direction of the non-U-shaped portion 6 in each primary conductor 4a, 4b, 4c is opposite to that of the first embodiment in the direction of the current flowing in the U-shaped portion 5 in the adjacent phase. The redundant part is omitted in the configuration as the other current sensor.
In the first embodiment, the non-U-shaped forming portion 6 is extended so that the direction of the current flowing through the U-shaped forming portion 5 in the adjacent phase is the same direction. The non-U-shaped forming part 6 is extended so that the direction of the current flowing through the U-shaped forming part 5 in the phase is opposite. However, the input terminal of the phase current applied to each primary conductor 4 shall be unified to the positive side (6aa, 6bb, 6ca) or the negative side (6ab, 6ba, 6cb) in the Z-axis direction, and mixed between the phases. Shall not.

The operation of the current sensor 2 in the third embodiment will be described with reference to FIGS. Note that FIG. 5 is used as a plan view of the current detection device unit 7.
When a current to be measured is applied to each primary conductor 4, for example, the first U-shaped portion 5aa has a right-rotating magnetic field as shown by one broken line in FIG. As shown by the other broken line in FIG. 15, a left-rotating magnetic field is generated in the character forming portion 5ab in accordance with the magnitude of the current to be measured. For the sake of simplicity, the generated magnetic field is shown by one magnetic flux line for each U-shaped portion. As a result, when the current detection device unit 7 is installed on the upper side of the U-shaped portion shown in FIG. 15, the magnetoresistive effect element (FIG. 5: 13c, 13d) located on the right side of the current detection device unit 7 has FIG. The resolving vector 12a is applied in the magnetosensitive direction (X-axis direction) of these magnetoresistive elements. That is, a magnetic field is applied to the magnetoresistive effect elements 13a and 13b shown in FIG. 5 on the XY plane of the current detection device unit 7 in the direction of the left side of the drawing with respect to the center line 10, and the magnetoresistive effect elements 13c and 13d have A magnetic field is applied in the direction of the right side of the drawing from the center line 10.
The feature of the generated magnetic field in the third embodiment is that it becomes an ellipse having a major axis in the lateral direction, that is, the X direction. This is determined by the direction of the current flowing in the U-shaped forming portions of the adjacent other phases, and when a current in the reverse direction flows in each U-shaped forming portion as in the third embodiment, the phases attract each other. Since the magnetic flux lines are formed in the shape, the elliptical shape extending in the lateral direction shown in FIG. 15 is formed.
On the other hand, the magnetic field generated in the first embodiment is an ellipse having a major axis in the vertical direction, that is, the Y direction as shown in FIG. 3, but this forms magnetic flux lines so as to repel each other. Because of this.
As a result, in the first embodiment and the third embodiment, even if the applied magnetic field vector 12 is the same size, the direction is different, so that it is applied in the magnetosensitive direction (X-axis direction) of the magnetoresistive effect element. The size of the decomposition vector 12a is different. Therefore, the magnetic field applied to the magnetosensitive direction of the magnetoresistive element increases without changing the positional relationship between the sensor substrate, the current detection device unit and the primary conductor, and the measured current value to be applied. The SN can be improved by reducing the axial magnetic field.
In the present embodiment, an example of detecting the current of a three-phase alternating current has been described. However, the present invention is not limited to three phases, and a plurality of primary conductors may be installed in a plurality of phases.

  As described above, according to the third embodiment, since the non-U-shaped portion 6 is extended so that the direction of the current flowing through the U-shaped portion 5 in the adjacent phase is opposite, the sensor The magnetic field applied in the magnetosensitive direction of the magnetoresistive effect element can be easily increased without changing the positional relationship between the substrate, the current detection device section and the primary conductor, and the measured current value to be applied, thereby improving the SN. .

Embodiment 4 FIG.
FIG. 17 shows a perspective view of a multiphase current detection apparatus 1 according to Embodiment 4 of the present invention. In the figure, the sensor board 3 of the main components, a U-shaped part 5 and a non-U-shaped part are shown. Only the primary conductor 4 composed of 6 is shown. In the figure, the non-U-shaped portion 6 of the primary conductor 4 is shown only in the vicinity of the sensor substrate 3 for simplicity, but it is assumed that processing such as connection to a power source and various devices is actually performed.
In the fourth embodiment, the non-U-shaped portions 6 of the respective primary conductors 4 are formed by bending or the like in the Z direction that is substantially perpendicular to the in-plane of the U-shaped portion 5 and the same direction. Therefore, the overlapping parts in the configuration as other current sensors are omitted. The non-U-shaped forming portion 6 of each primary conductor 4 in Embodiment 1 was subjected to bending or the like in the Z direction that is substantially perpendicular to the in-plane of the U-shaped forming portion 5 and in the opposite direction. However, the non-U-shaped forming portion 6 of the fourth embodiment is subjected to bending or the like in the Z direction that is substantially perpendicular to the in-plane of the U-shaped forming portion 5.

The overall configuration of multiphase current detection apparatus 1 according to Embodiment 4 will be described. In the first to third embodiments, the primary conductors 4 are all configured to extend in one direction (here, the Z direction), and the current sensor 2 is inserted in the middle thereof. On the other hand, the fourth embodiment is a configuration example of the primary conductor 4 in the multiphase current detection device 1 when the input / output ends of the primary conductor 4 do not extend in one direction and are arranged together on the same side. It is shown.
In various devices in which a current sensor is installed, for example, it may be required to directly install a current sensor at a terminal portion of a terminal block, and has a primary conductor extending in one direction as in the first to third embodiments. There were cases where the current sensor configuration was not suitable for miniaturization. According to the present embodiment, it is possible to configure a multiphase current detection device without reducing the performance even if the input / output terminals are collectively arranged on one side.
In the present embodiment, an example in which the sensor substrate 3 is installed on the upper side of the U-shaped forming portion 5 is shown, but the installation position is not limited to the upper side, but on the lower side, that is, on the near side in FIG. May be installed. However, in order to support multiphase detection with one sensor substrate, it is desirable to fix the installation position on either side.

  As described above, according to the fourth embodiment, each non-U-shaped forming portion 6 is subjected to bending or the like in the Z direction which is substantially perpendicular to the U-shaped forming portion 5 and in the same direction. Due to the configuration, even when it is required to install the input and output ends of the primary conductor 4 together on the same side, there is an effect that the measurement accuracy can be kept small without degrading the measurement accuracy.

1 is a perspective view of a multiphase current detection device according to Embodiment 1 of the present invention. FIG. It is a top view of the current sensor by Embodiment 1 of this invention. It is sectional drawing of the current sensor by Embodiment 1 of this invention. It is a figure which shows the magnetic field vector and decomposition | disassembly vector of the current detection device part one side (right side) vicinity shown in FIG. 3 of the current sensor by Embodiment 1 of this invention. It is a top view which shows the current detection device part of the current sensor by Embodiment 1 of this invention. It is a structure schematic diagram which shows the current detection device part of the current sensor by Embodiment 1 of this invention. It is a block diagram which has arrange | positioned the compensation electrically conductive line by Embodiment 1 of this invention. It is each primary conductor top view of the detection apparatus of the multiphase current by Embodiment 1 of this invention. It is each primary conductor top view of the detection apparatus of the multiphase current different from Embodiment 1 of this invention. It is each primary conductor top view of the detection apparatus of the other multiphase current by Embodiment 1 of this invention. It is each primary conductor top view of the detection apparatus of the further another polyphase current by Embodiment 1 of this invention. It is a top view of the detection apparatus of the multiphase current by Embodiment 2 of this invention. It is sectional drawing of the detection apparatus of the multiphase current by Embodiment 2 of this invention. It is a perspective view of the detection apparatus of the multiphase current by Embodiment 3 of this invention. It is sectional drawing of the current sensor by Embodiment 3 of this invention. It is a figure which shows the magnetic field vector and decomposition | disassembly vector of the electric current sensor by Embodiment 3 of this invention near the electric current detection device part one side (right side) shown in FIG. It is a perspective view of the detection apparatus of the multiphase current by Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Detection apparatus of multiphase current, 2 Current sensor, 3 Sensor board, 4 Primary conductor, 5 U-shaped formation part, 6 Non-U-shaped formation part, 7 Current detection device part, 8 Sensor circuit part, 9 External terminal, 10 center Line, 11 Device installation part, 12 Magnetic field vector, 13 Magnetoresistive element, 14 Connection current line, 15 Connection area, 16 Installation board, 17 Bridge circuit, 18 Half bridge circuit, 19 Compensation conductive line, 20 Operational amplifier, 21 Axis of symmetry , 22 X direction magnetic field

Claims (8)

First and fourth magnetoresistive elements disposed on an installation substrate and having a magnetoresistive effect characteristic in which a resistance value increases together with an increase in a magnetic field opposite to each other;
Second and third magnetoresistive elements arranged on the installation substrate and having magnetoresistive effect characteristics in which the resistance value decreases together with the increase of the magnetic field in the opposite direction;
The first half bridge circuit by the first and second magnetoresistive effect elements, and the third and second magnetoresistive effect elements are arranged on the installation substrate and connected to the first to fourth magnetoresistive effect elements. A connection current line constituting a bridge circuit composed of a second half-bridge circuit by four magnetoresistive elements,
A current detection device in which the first half-bridge circuit is arranged in one region divided with respect to the center line of the installation board and the second half-bridge circuit is arranged in the other region; A plurality of primary conductors each having a single U-shaped portion;
The current detection device is arranged in the vicinity of each U-shaped portion so that the center line of each of the installation boards and each symmetry axis of the U-shaped portion substantially coincide with each other, and the non-U-shaped primary conductor is formed. The parts extend in the out-of-plane direction of the U-shaped part, the U-shaped parts are arranged in parallel in the same plane, and the symmetry axes of adjacent U-shaped parts are not on the same straight line. Multiphase current detector.   An apparatus for detecting a multiphase current, wherein the adjacent U-shaped forming portions are arranged in parallel outside the same plane, and the symmetry axis of the U-shaped forming portion is in the same plane.   An apparatus for detecting a multiphase current, wherein the adjacent U-shaped portions are arranged in parallel outside the same plane, and the symmetry axis of the adjacent U-shaped portions is outside the same plane.   The current detection device is installed on a sensor board together with a sensor circuit unit, and the sensor board is arranged at least at one location within a region surrounded by the primary conductor forming a U-shape and a U-shape with the center line of the installation board. The multiphase current detection device according to claim 1, wherein the symmetry axes of the forming portions are arranged to substantially coincide with each other.   5. The multi-phase current according to claim 1, wherein in the primary conductor, a non-U-shaped portion extending in an out-of-plane direction of the U-shaped portion is in the same direction in each phase. Detection device.   5. The multiphase current according to claim 1, wherein in the primary conductor, the extending direction of the non-U-shaped forming portion extending in the out-of-plane direction of the U-shaped forming portion is opposite in each phase. Detection device.   The multiphase current detection device according to claim 1, wherein the direction of the current to be measured flowing in the U-shaped forming portion is the same direction with respect to the adjacent phase.   The multiphase current detection device according to claim 1, wherein the direction of the current to be measured flowing in the U-shaped forming portion is opposite to the adjacent phase.

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