JP2009020085A - Multiphase current detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detector capable of more correctly detecting multiphase current by considering multiple phase currents instead of the conventional current sensor having primary conductors of U-shape, each of left and right half bridge circuits of the bridge circuit is subjected to reverse directional magnetic fields having a merit for eliminating an effect of uniform external field while only considering a single phase measurement. <P>SOLUTION: The multiphase current detector is arranged such that respective U-shape parts are arranged parallelly in the same surface but the symmetric axes of the U-shape parts should not exist on a straight line. Therefore, at the time of detecting the multiphase current the influence of magnetic field generated by the other phase current are reduced and the effect for detecting the more correct current can be expected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multiphase current detection device that detects an applied multiphase current to be measured in the vicinity of a plurality of primary conductors having a U-shaped portion.

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

  In addition, as a multiphase current detection device, there is a device in which a surface mount type current sensor is arranged at the center of a detected current path bent at a right angle in a crank shape twice (for example, see Patent Document 2).

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

  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, only a single-phase measurement is assumed, and there has been a problem that a configuration in which multiphase current detection is performed more accurately by reducing the influence of other phase currents 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 the current of a certain phase is affected by the magnetic flux generated by the current of another phase. In this configuration, the multiphase current can be detected more accurately. However, as shown in Patent Document 1, multiphase detection is performed by a current sensor using a primary conductor having a U-shaped portion in which a reverse magnetic field is applied to each of the left and right half bridges of a bridge circuit composed of magnetoresistive elements. In the case of the configuration, there is a problem that a simple arrangement is easily affected by other phases and detection errors increase.

  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 a multi-phase current, and a more accurate current can be detected. It aims at obtaining the detection apparatus of a polyphase electric current.

  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. And a plurality of primary conductors each having a second half bridge circuit disposed in the other region and a primary conductor having at least one U-shaped portion. In the vicinity of the U-shaped part, the center line of the installation board and the symmetry axis of the U-shaped part are substantially aligned, and the U-shaped part adjacent to each U-shaped part is symmetrical. They are arranged in parallel in the same plane so that the axes 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, each primary conductor is arranged in parallel in the same plane so that the symmetry axis of the U-shaped part adjacent to each U-shaped part is not on the same straight line. This has the effect of reducing the influence of the magnetic field generated by the phase current and detecting a more accurate current.

Embodiment 1 FIG.
1 is a perspective view of a multiphase current detection device 1 according to Embodiment 1 of the present invention. FIG. 2 is a plan view of a current sensor for one phase of FIG. 1, and FIG. It is sectional drawing which shows a part of (XZ surface). In the figure, a multiphase current detection device 1 is an example in which each phase current is detected by a current sensor installed for each phase in a three-phase alternating current, and a current sensor 2 for one phase includes a current detection device unit. 7, the sensor substrate 3 having the sensor circuit unit 8 and the primary conductor 4. In the figure, the primary conductor 4 is shown only in the vicinity of the current sensor unit for simplicity, but it is actually extended and connected to a power source, various devices, and the like.
In the first embodiment, each primary conductor 3 is bent substantially perpendicularly in the longitudinal direction to form one U-shaped portion 6 and is surrounded by the primary conductor in the U-shaped portion 6. One current detection device unit 7 is arranged in the space 11.
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, a part of each primary conductor 4 to which a current to be measured is applied is bent substantially perpendicularly in the longitudinal direction so as to have a U-shape when viewed from the Z direction. One U-shaped portion 6 is formed. 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 provided with the U-shaped primary conductors 5 on both sides. As long as it has a structure to which a magnetic field in the reverse direction is applied, it may have a rounded shape or the like, but is not limited to this, but in order to stably apply a magnetic field in the reverse direction, the U-shape is at least a current detection device. In the vicinity of the part 7, it is desirable that it is bilaterally symmetric.
As shown in FIG. 2, the sensor substrate 3 is installed on the lower surface of the U-shaped part 6 so that the symmetry axis of the U-shaped part 6 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 lower surface of the U-shaped portion 6 is shown, but the installation position is not limited to the lower surface.
The installation position (especially in the Z direction) of the current detection device unit 7 is determined according to the magnetic field desired to be applied to the magnetoresistive effect element 13, that is, the magnitude of the current to be measured. At this position (broken line O in FIG. 3), the applied magnetic field in the magnetosensitive direction becomes 0, so it is preferable to install it at a position shifted from the center. In the present embodiment, an example in which the current detection device unit 7 is installed in the space part 11 is shown, but the present invention is not limited to this, and the current detection device part 7 may be placed outside the space part 11. Further, the cross-sectional area of the primary conductor 4 is determined according to the magnitude of the applied constant current value. Such a primary conductor 4 is produced, for example, by bending the U-shaped portion 6 from a linear conductor bar shape made of 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.
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 primary conductor 5 ′ has a left-rotating magnetic field as shown by a broken line in FIG. As shown by the broken line in FIG. 3, a right-rotating magnetic field is generated in the character-forming primary conductor 5 ″ according to the magnitude of the current to be measured as shown by the broken line in FIG. The magnetic field generated by two magnetic flux lines for each primary conductor is shown in Fig. 5. As a result, when the current detection device unit 7 is installed near the lower surface of the space 11, the magnetoresistive element located on the right side of the current detection device unit 7 is shown. 4 is applied to the effect elements 13c and 13d, and the decomposition vector 12a is applied in the magnetosensitive direction (X direction) of the magnetoresistive effect elements 13c and 13d. As shown in FIG. 5 in the XY plane of the portion 7 A magnetic field is applied to the magnetoresistive elements 13a and 13b in the direction of the left side of the paper from the center line 10, and a magnetic field is applied to the magnetoresistive elements 13c and 13d in the direction of the right side of the paper 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 of the primary conductors 4a, 4b, and 4c and the sensor substrates 3a, 3b, and 3c in the multiphase current detection device 1, and FIG. 9 is a BB cross section (YZ plane) of FIG. FIG. 10 is a cross-sectional view, and FIG. 10 is a diagram showing the direction of main magnetic fields generated in each primary conductor.
The three primary conductors 4a, 4b, 4c corresponding to each phase are substantially parallel in the longitudinal direction (X direction) as shown in FIG. 8, arranged in parallel in the XY plane as shown in FIG. It arrange | positions so that the symmetry axis 21 of the U-shaped part to be may not be on the same straight line. When a current to be measured is applied to each primary conductor 4a, 4b, 4c, the direction of the main magnetic field generated is all in the X direction or Y direction on the XY plane as shown by the arrows in FIG. Here, the magnetosensitive effect elements (not shown in the figure) installed on the sensor substrates 3a, 3b, and 3c are in the X direction, and the U-shaped portions 6a, 6b, and 6c that serve as the magnetic field detection units. The direction of the magnetic field applied from the primary conductor to the portion sandwiched between the U-shaped primary conductors is the X-direction magnetic field 22 of the detection unit or the Y-direction magnetic field 23 of the detection unit, and Y is perpendicular to the magnetic sensing direction. Unaffected by the magnetic field in the direction. The magnetic field direction 24 of the non-detection part generated in the other non-detection part is also the Y direction perpendicular to the magnetic sensing direction of the magnetoresistive effect element, so that the magnetoresistive effect element generates a magnetic field generated outside the magnetic field detection part. Will not be affected. Therefore, in order to reduce the influence from the X-direction magnetic field 22 of the detection unit generated in the adjacent U-shaped part, the symmetrical axes are separated so that the symmetrical axes of the adjacent U-shaped parts are not on the same straight line. If each primary conductor is installed, the error due to the current of the other phase 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.

  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, 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, a uniform external magnetic field can be removed.

  In addition, the magnetic field in the magnetosensitive direction applied from the primary conductor of the other phase to the magnetoresistive effect element unit serving as the magnetic field detection unit is separated from the symmetry axis so that the symmetry axis of the adjacent U-shaped part is not on the same straight line. The direction of the magnetic field generated in addition to the magnetic-sensitive magnetic field applied from the primary conductor of the other phase is perpendicular to the magnetic sensitive direction. There is an effect to improve the measurement accuracy without receiving.

Embodiment 2. FIG.
FIG. 11 shows a plan view of the primary conductors 4a, 4b, 4c and the sensor boards 3a, 3b, 3c in the multiphase current detection apparatus 1 according to Embodiment 2 of the present invention. FIG. 13 is a cross-sectional view showing a cross section (YZ plane) along the axis of symmetry 21 in FIG. 11. In the second embodiment, the symmetry axes 21 of the U-shaped portions of the primary conductors 4a, 4b, and 4c are in the same plane, and the primary conductors 4a, 4b, and 4c are not on the same plane. The primary conductors 4a, 4b, and 4c are installed.
In the second embodiment, the arrangement configuration of the primary conductors 4a, 4b, and 4c is changed from that in the first embodiment, and the redundant portions are omitted in the configuration as other current sensors. In the first embodiment, the U-shaped portions of the primary conductors 4a, 4b, and 4c are shifted in the XY plane. In the second embodiment, the primary conductors 4a, 4b, and 4c are arranged in the YZ plane. The U-shaped part of is installed by shifting.

The overall configuration of multiphase current detection apparatus 1 in the second embodiment will be described.
As shown in FIG. 11, the three primary conductors 4a, 4b, and 4c corresponding to each phase are substantially parallel in the longitudinal direction (X direction) in the XY plan view viewed from the Z-axis direction. As shown in FIG. 3, the U-shaped portion is arranged so that the symmetry axis 21 is shifted from the XY plane in the Z direction and is in the same plane. In the first embodiment, the sensor substrates 3a, 3b, and 3c may be installed on either the upper surface or the lower surface of the primary conductors 4a, 4b, and 4c. In the second embodiment, the sensor substrates 3a, 3b, and 3c are shown in FIG. Thus, it is desirable that the sensor substrates 3a and 3c be installed on the lower surface of the primary conductors 4a and 4c, and the sensor substrate 3b be installed on the upper surface of the primary conductor 4b.
When a current to be measured is applied to each primary conductor 4a, 4b, 4c, the direction of the main magnetic field generated is all in the X direction or the Y direction on the XY plane. Here, the magnetosensitive effect elements (not shown in the figure) installed on the sensor substrates 3a, 3b, and 3c are in the X direction, and the U-shaped portions 6a, 6b, and 6c that serve as the magnetic field detection units. The direction of the magnetic field applied from the primary conductor to the portion sandwiched by the U-shaped primary conductor is the X direction or the Y direction, and is not affected by the magnetic field in the Y direction, which is perpendicular to the magnetic sensing direction. The direction of the magnetic field generated in the other non-detection parts is also the Y direction perpendicular to the magnetosensitive effect direction of the magnetoresistive effect element, so that the magnetoresistive effect element is also affected by the magnetic field generated outside the magnetic field detection part. There is no. Therefore, in order to reduce the influence from the X-direction magnetic field generated in the adjacent U-shaped part, the primary conductors are spaced apart in the Z direction so that the U-shaped part is not adjacent in the YZ plane, and If the sensor substrate is installed apart from the adjacent U-shaped portion, it is possible to reduce errors due to currents in other phases.
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 second embodiment, the magnetic field in the magnetosensitive direction applied from the primary conductor of the other phase to the magnetoresistive effect element portion serving as the magnetic field detecting portion is adjacent to the U-shaped portion on the YZ plane. Other than the magnetic field in the magnetosensitive direction applied from the primary conductor of the other phase, and the primary conductors are separated from each other in the Z direction and the sensor substrate is placed away from the adjacent U-shaped portion. Since the direction of the generated magnetic field is a direction perpendicular to the magnetic sensing direction, there is an effect of improving the measurement accuracy without being affected by the magnetic field due to the current of the other phase.

  In addition, when the space for installing the current sensor is limited in the X-axis direction and the configuration of the first embodiment is difficult, this configuration can improve the measurement accuracy without being affected by the magnetic field due to the current of the other phase. There is an effect that can be installed while maintaining the effect of increasing.

Embodiment 3 FIG.
FIG. 14 shows a plan view of the primary conductors 4a, 4b, 4c and the sensor substrate 3 in the multiphase current detection apparatus 1 according to Embodiment 3 of the present invention, and FIG. It is sectional drawing which shows a cross section (YZ surface). In the third embodiment, the symmetry axis 21 of the U-shaped portion of each primary conductor 4a, 4b, 4c is out of the same plane, and each primary conductor 4a, 4b, 4c is not in the same plane. The primary conductors 4a, 4b, and 4c are installed.
In the third embodiment, the arrangement configuration of the primary conductors 4a, 4b, and 4c is changed from that in the first embodiment, and the redundant portions are omitted in the configuration as other current sensors. In the first embodiment, the U-shaped portions of the primary conductors 4a, 4b, and 4c are shifted in the XY plane. However, in the third embodiment, the primary conductor 4b is further moved in the Z direction in the YZ plane. It was installed by shifting.

The overall configuration of multiphase current detection apparatus 1 in the third embodiment will be described.
As shown in FIG. 15, the three primary conductors 4a, 4b, and 4c corresponding to each phase are substantially parallel in the longitudinal direction (X direction) in the XY plan view as seen from the Z-axis direction as shown in FIG. Are arranged so as to be shifted in the Z direction outside the XY plane, and arranged so that the symmetry axis 21 of the U-shaped portion is not in the same plane. In the second embodiment, as shown in FIG. 13, the sensor boards 3a and 3c are installed with the lower surfaces of the primary conductors 4a and 4c, and the sensor board 3b is installed with the upper surface of the primary conductor 4b and each sensor board spaced apart. Although desired, in the third embodiment, it is desirable that the sensor substrate 3 be installed on the upper surface of the primary conductors 4a and 4c and the lower surface of the primary conductor 4b so that the sensor substrate 3 is accommodated on one sensor substrate 3.
When a current to be measured is applied to each primary conductor 4a, 4b, 4c, the direction of the main magnetic field generated is all in the X direction or the Y direction on the XY plane. Here, the magnetosensitive effect element (not shown in the figure) installed on the sensor substrate 3 is in the X direction, and the U-shaped portions 6a, 6b, and 6c forming the magnetic field detecting portions are formed. The direction of the magnetic field applied from the primary conductor to the portion sandwiched between the primary conductors is the X direction or the Y direction, and is not affected by the magnetic field in the Y direction that is perpendicular to the magnetic sensing direction. The direction of the magnetic field generated in the other non-detection parts is also the Y direction perpendicular to the magnetosensitive effect direction of the magnetoresistive effect element, so that the magnetoresistive effect element is also affected by the magnetic field generated outside the magnetic field detection part. There is no. Therefore, in order to reduce the influence from the X-direction magnetic field generated in the adjacent U-shaped part, the primary conductors are separated from each other so that the symmetrical axes of the adjacent U-shaped parts are not on the same straight line. If this is installed, it is possible to reduce errors caused by currents in other phases.
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, the magnetic field in the magnetosensitive direction applied from the primary conductor of the other phase to the magnetoresistive effect element unit serving as the magnetic field detection unit is the symmetry axis of the adjacent U-shaped unit. Is reduced by separating the symmetry axes so that they are not on the same straight line, and the direction of the magnetic field generated in addition to the magnetic field in the magnetic direction applied from the primary conductor of the other phase is perpendicular to the magnetic direction. Therefore, the measurement accuracy is improved without being affected by the magnetic field due to the current of the other phase.

  In addition, since a plurality of current detection device units can be installed on one sensor substrate, not only one sensor substrate is provided, but also the current detection device unit can be easily positioned, resulting in cost reduction.

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 vicinity 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 a top view of the detection apparatus of the multiphase current by Embodiment 1 of this invention. It is sectional drawing of the detection apparatus of the multiphase current by Embodiment 1 of this invention. It is a figure which shows the direction of the magnetic field which generate | occur | produces in the primary conductor vicinity of the detection apparatus of the multiphase 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 another sectional drawing of the detection apparatus of the multiphase current by Embodiment 2 of this invention. It is a top view of the detection apparatus of the multiphase current by Embodiment 3 of this invention. It is sectional drawing of the detection apparatus of the multiphase current by Embodiment 3 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 primary conductor, 6 U-shaped part, 7 Current detection device part, 8 Sensor circuit part, 9 External terminal, 10 Center line, 11 space part, 12 magnetic field vector, 13 magnetoresistive effect 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 symmetry axis , 22 X-direction magnetic field of the detection unit, 23 Y-direction magnetic field of the detection unit, 24 Magnetic field direction of the non-detection unit

Claims (4)

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-shape,
The current detection devices are arranged in the vicinity of the U-shaped portions so that the center lines of the installation boards and the symmetry axes of the U-shaped shapes substantially coincide with each other. A multiphase current detection device, wherein the 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.   An apparatus for detecting a multiphase current, wherein the U-shaped portions are arranged in parallel outside the same plane, and the symmetry axis of the U-shaped portion is in the same plane.   An apparatus for detecting a multiphase current, wherein the U-shaped portions are arranged in parallel outside the same plane, and the symmetry axes of adjacent U-shaped portions are out of the same plane.   The current detection device is installed on a sensor board together with a sensor circuit unit, and the sensor board forms a U-shape and is located at least at one place in a space surrounded by the primary conductor and the center line of the installation board and U The multiphase current detection device according to claim 1, wherein the symmetry axes of the letter-shaped shapes are arranged so as to substantially coincide with each other.

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