WO2013038867A1 - Electric-current sensor - Google Patents

Electric-current sensor Download PDF

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Publication number
WO2013038867A1
WO2013038867A1 PCT/JP2012/070817 JP2012070817W WO2013038867A1 WO 2013038867 A1 WO2013038867 A1 WO 2013038867A1 JP 2012070817 W JP2012070817 W JP 2012070817W WO 2013038867 A1 WO2013038867 A1 WO 2013038867A1
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WIPO (PCT)
Prior art keywords
current path
current
sub
main
path
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PCT/JP2012/070817
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French (fr)
Japanese (ja)
Inventor
蛇口　広行
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アルプス・グリーンデバイス株式会社
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Publication of WO2013038867A1 publication Critical patent/WO2013038867A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
    • G01R15/207—Constructional details independent of the type of device used

Definitions

  • the present invention relates to a current sensor that can measure the current flowing through a conductor while eliminating the influence of a disturbance magnetic field.
  • a current sensor that can measure these large currents in a non-contact manner is required.
  • a current sensor that detects a change in a magnetic field caused by a current to be measured by a plurality of magnetic sensors has been proposed.
  • a current sensor has been proposed in which differential processing is performed on detection values obtained by two magnetosensitive elements to eliminate the influence of a disturbance magnetic field.
  • an opening is formed in the central portion of the current path and branches into two of the first and second current paths.
  • the first current path is located in the vicinity of the first current path.
  • a first magnetosensitive element for detecting a magnetic field due to a current flowing through the current path is provided, and a second sensitivity for detecting a magnetic field due to the current flowing through the second current path is provided in the vicinity of the second current path.
  • a magnetic element is provided. The first magnetosensitive element and the second magnetosensitive element are almost equally affected by the external magnetic field.
  • the distance from one current path is set to the other current path for each of the first and second magnetosensitive elements. It is necessary to make it sufficiently smaller than the distance. As a result, in the above-described current sensor, it is necessary to increase the distance between the first magnetosensitive element and the second magnetosensitive element arranged between the first current path and the second current path. Therefore, the current sensor cannot be reduced in size.
  • the present invention has been made in view of such points, and in a current sensor that eliminates the influence of an external magnetic field by performing arithmetic processing on detection values of two magnetosensitive elements while maintaining current measurement accuracy.
  • An object of the present invention is to provide a current sensor that can be miniaturized.
  • the current sensor of the present invention includes a main current path and a current path including a region formed by a pair of sub current paths arranged in parallel at intervals on both sides of the main current path; A pair of magnetosensitive elements provided between the current path and each sub-current path, and an arithmetic circuit that calculates the current value of the main current path based on the detection value of the pair of magnetosensitive elements.
  • the resistance values of the pair of sub current paths are equal, and the resistance values of the main current path are different from the resistance values of the pair of sub current paths.
  • the induced magnetic field due to the current to be measured is not canceled out.
  • the magnetosensitive element reliably detects the induced magnetic field due to the current to be measured. can do.
  • the measurement accuracy of the current value of the current path can be maintained without increasing the distance between the pair of magnetosensitive elements, and the current sensor can be downsized.
  • the pair of magnetosensitive elements may be provided so as to be symmetrical with respect to the center of the main current path in a sectional view of the region.
  • the pair of magnetosensitive elements includes a direction in which the main current path and the sub current path are arranged, and a direction in which current flows through the main current path and the sub current path.
  • Each may be arranged so as to have a sensitivity axis in a direction parallel to the orthogonal direction. According to this configuration, the direction of the magnetic field in the main current path detected by each magneto-sensitive element and the direction of the magnetic field in the sub current path are reversed, and the mutual magnetic fields are offset. Even when current flows, the measurement accuracy of the current value in the main current path can be maintained.
  • the main current path and the sub current path may be made of the same material, and the cross-sectional areas in the cross-sectional view of the region may be different. According to this configuration, since the main current path and the sub current path can be made of the same material, the current sensor can be manufactured more easily.
  • the width of the main current path may be narrower than the width of the sub current path. According to this configuration, the distance between the first magnetosensitive element and the second magnetosensitive element can be further reduced, the current sensor can be reduced in size, and noise can be placed near the current sensor. The influence of the external magnetic field with the source can also be effectively canceled by the differential processing, and the measurement accuracy can be improved.
  • the current path has a flat plate shape, and the region includes a pair of slits formed in a direction parallel to a direction in which current flows through the main current path and the sub current path. You may comprise by forming in an electric current path.
  • each of the main current path and the sub current path has a flat plate shape, and the current path is configured by connecting the surface of the main current path and the surface of the sub current path. In the region, the main current path and the sub current path may be spaced apart.
  • the current sensor of the present invention includes a main current path and a current path including a region formed by a pair of sub current paths arranged in parallel at intervals on both sides of the main current path; A pair of magnetosensitive elements provided between the current path and each sub-current path, and an arithmetic circuit that calculates the current value of the main current path based on the detection value of the pair of magnetosensitive elements.
  • the strength of the magnetic field generated by the pair of sub-current paths is the same and the direction of the magnetic field is opposite, the strength of the magnetic field generated by the main current path and the strength of the magnetic field generated by the sub-current path Are different.
  • the intensity of the magnetic field applied to the pair of magnetosensitive elements by the main current path is different from the intensity of the magnetic field applied to the pair of magnetosensitive elements by the sub current path, so that the induced magnetic field due to the current to be measured cancels out. There is no end to it.
  • the magnetosensitive element reliably detects the induced magnetic field due to the current to be measured. can do.
  • the measurement accuracy of the current value of the current path can be maintained without increasing the distance between the pair of magnetosensitive elements, and the current sensor can be downsized.
  • a current sensor that eliminates the influence of an external magnetic field by performing arithmetic processing on detection values of two magnetosensitive elements, a current sensor that can be reduced in size while maintaining current measurement accuracy is provided. it can.
  • FIG. 4 is a schematic diagram showing a current sensor according to Embodiment 1.
  • FIG. 3 is a circuit diagram illustrating an example of a current sensor according to Embodiment 1.
  • FIG. 6 is a schematic diagram showing a current sensor according to Embodiment 2.
  • FIG. 6 is a schematic diagram showing a current sensor according to Embodiment 3.
  • FIG. 6 is a schematic diagram showing a current sensor according to a fourth embodiment. It is a schematic diagram which shows the current sensor which concerns on a modification.
  • the present inventor has a plurality of current paths branched when canceling the influence of the disturbance magnetic field.
  • this inventor makes resistance value between several electric current paths differ in view of not being able to reduce in size, if a difference is provided between induction magnetic fields by adjusting the distance between a magnetosensitive element and an electric current path. As a result, it was found that a difference can be provided between the induction magnetic fields, and the present invention has been achieved.
  • the essence of the present invention is that the main current path and the main current path of the type of current sensor that eliminates the influence of the disturbance magnetic field by calculating (difference or sum) the detection values of the two magnetosensitive elements.
  • a current path including a region composed of a pair of sub-current paths arranged in parallel at intervals on both sides, and in this region, a pair of magnetosensitive elements is provided between the current path and each sub-current path.
  • the resistance value of the pair of sub current paths is made equal, and the resistance value of the main current path is made different from the resistance value of the pair of sub current paths, thereby reducing the size while maintaining the current measurement accuracy.
  • FIG. 1 is a schematic diagram showing a current sensor 1 of the present embodiment.
  • 1A is a top view of the current sensor 1
  • FIG. 1B is a cross-sectional view taken along line IB-IB in FIG. 1A.
  • a current sensor 1 includes a current path 2 in which a pair of openings 2a and 2b are formed in a plate-shaped conductor, and magnetosensitive elements 3a and 3b disposed in the openings 2a and 2b, respectively. It is equipped with.
  • the pair of openings 2a and 2b are connected to the current path 2 in a direction parallel to the direction in which current flows through the current path 2 (particularly the main current path and the sub current path). It is a pair of formed slits.
  • the current path 2 has a pair of sub-currents arranged in parallel with the openings 2 a and 2 b on both sides of the main current path 21 and the main current path 21. Branches to current paths 22 and 23.
  • the main current path 21 and the pair of sub current paths 22 and 23 form a current path region R.
  • the current path 2 includes a main current path 21 and sub-current paths 22 and 23 that are arranged in parallel at intervals on both sides of the main current path 21.
  • the current flowing through the current path 2 includes a current flowing through the main current path 21 (hereinafter referred to as main current) I, a current flowing through the sub current path 22 (hereinafter referred to as sub current) I2, and a sub current.
  • the current is divided into three currents (hereinafter referred to as subcurrents) I3 flowing through the path 23.
  • the current sensor 1 shown in FIG. 1A is configured such that the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different.
  • the resistance value is different between the main current path 21 and the sub current paths 22 and 23
  • the cross sectional area of the main current path 21 and the cross section area of the sub current paths 22 and 23 may be different from each other.
  • the material of the main current path 21 and the material of the sub current paths 22 and 23 may be different. In the current sensor 1 shown in FIG.
  • the cross-sectional areas of the sub-current paths 22 and 23 are made equal, and the cross-sectional area of the sub-current paths 22 and 23 is made larger than the cross-sectional area of the main current path 21. Therefore, the current values of the subcurrents I2 and I3 flowing through the subcurrent paths 22 and 23 are equalized, and the main current I1 flowing through the main current path 21 and the subcurrents I2 and I3 flowing through the subcurrents 22 and 23 are equalized. Are different from each other (I1> I2, I3 or I1 ⁇ I2, I3). For this reason, the strength of the magnetic field generated by the main current path 21 is different from the strength of the magnetic field generated by the sub current paths 23 and 23.
  • the cross-sectional area is appropriately adjusted by changing the width (X direction) and thickness (Z direction) in FIG. 1B. By changing the cross-sectional area in this way, the current sensor 1 can be easily manufactured. Further, when the material of the main current path 21 and the material of the sub current paths 22 and 23 are different, the cross sectional area of the main current path 21 and the cross sectional area of the sub current paths 22 and 23 can be made equal.
  • the induced magnetic field B1 of the main current path 21 And the induced magnetic fields B2 and B3 of the auxiliary current paths 22 and 23 can be increased, so that even if the current I to be measured is a large current of several hundred A level, the magnetosensitive The elements 3a and 3b can be prevented from being magnetically saturated, and current can be measured accurately.
  • the magnetosensitive elements 3a and 3b are provided between the main current path 21 and the sub current paths 22 and 23, respectively.
  • the magnetic sensitive elements 3 a and 3 b are arranged at positions symmetrical with respect to the center of the main current path 21.
  • the magnetosensitive elements 3a and 3b include a direction in which the main current path 21 and the sub current paths 22 and 23 are arranged (the X direction in FIG. 1B), the main current path 21 and They are arranged so as to have a sensitivity axis in a direction parallel to a direction (Z direction in FIG. 1B) orthogonal to a direction (Y direction in FIG.
  • the magnetic sensitive elements 3a and 3b have sensitivity axis directions 32a and 32b, respectively.
  • the magnetosensitive elements 3a and 3b are arranged so that the sensitivity axis directions 32a and 32b are in the same direction, but are arranged so that the sensitivity axis directions 32a and 32b are opposite to each other. Also good.
  • the magnetic sensitive elements 3 a and 3 b have sensitivity axis directions 32 a and 32 b parallel to the pair of main surfaces 31.
  • the magnetic sensitive element 3 a has one main surface 31 in contact with the side surface 211 of the main current path 21.
  • the magnetic sensitive element 3b is arranged such that one main surface 31 is in contact with the side surface 212 of the main current path 21.
  • one main surface 31 is the side surface 221 of the sub-current path 22 so that the induced magnetic field B2 oriented parallel to the side surface 221 of the sub-current path 22 can be easily detected.
  • one main surface 31 is a side surface of the sub-current path 23 so that the induced magnetic field B3 oriented parallel to the side surface 231 of the sub-current path 23 can be easily detected.
  • 231 may be arranged so as to be in contact with 231.
  • the sensitivity axes of the sensitivity elements 3a and 3b are such that the current passes through the main current path 21 and the sub current paths 22 and 23 (the X direction in FIG. 1B) and the main current path 21 and the sub current path 22.
  • the sensitivity is maximized when the direction is parallel to the direction (Z direction in FIG. 1B) perpendicular to the flowing direction (Y direction in FIG. 1B), but is not limited thereto.
  • the sensitivity axes of the sensitivity elements 3a and 3b are on the YZ plane (excluding the Y direction) in FIG. 1B and are in any direction as long as the pair of sensitivity elements 3a and 3b are parallel to each other. May be.
  • the direction of the induced magnetic field B1 in the main current path 21 is opposite to the direction of the induced magnetic field B3 in the subcurrent path 23 (downward in FIG. 1B).
  • the magnetosensitive element 3b detects the combined induction magnetic field b (B1-B3) canceled by the induction magnetic field B3 of the sub current path 23.
  • the magnetosensitive elements 3a and 3b detect the combined induction magnetic fields canceled by the induction magnetic fields B2 and B3 of the sub current paths 22 and 23, respectively. Further, as will be described in detail later, the disturbance magnetic field in the direction parallel to the sensitivity axis directions 32a and 32b of the magnetic sensitive elements 3a and 3b can be canceled by the differential operation of the magnetic sensitive elements 3a and 3b. The influence of the disturbance magnetic field can be eliminated.
  • the magnetosensitive elements 3a and 3b for example, a magnetoresistive element such as a GMR (Giant Magneto Resistance) element or a TMR (Tunnel Magneto Resistance) element, a magnetic sensor using a Hall element, or the like can be applied.
  • the magnetoresistive effect element has a sensitivity axis parallel to the pair of main surfaces 31 of the magnetosensitive elements 3a and 3b.
  • the openings 2a and 2b of the current path 2 are arranged. Since the induced magnetic field B1 can be detected by providing it on the side surface of the current path, it is preferable in terms of ease of mounting.
  • FIG. 2 is a circuit diagram showing a current sensor according to the present invention.
  • the current sensor shown in FIG. 2 is a signal processing circuit (arithmetic circuit) that outputs a pair of magnetic sensitive elements 3a and 3b and signal processing (current value is calculated) of detection results from the magnetic sensitive elements 3a and 3b. 4.
  • the magnetosensitive element 3 a detects the combined induction magnetic field a canceled by the induction magnetic field B 2 of the sub current path 22, and a voltage signal having a magnitude proportional to the detected magnetic field is output to the signal processing circuit 4.
  • a voltage signal having a magnitude proportional to the detected magnetic field is output to the signal processing circuit 4.
  • the voltage signal Va output from the magnetosensitive element 3a is expressed by equation (1), where k is a proportional constant.
  • the magnetic field in the same direction as the sensitivity axis direction of the magnetic sensing element 3a is +, and the magnetic field in the opposite direction is-.
  • Va k * ⁇ ( ⁇ B1 + B2) ⁇ B ⁇ (1)
  • the magnetosensitive element 3 b detects the combined induction magnetic field b canceled by the induction magnetic field B 3 of the sub current path 23, and a voltage signal having a magnitude proportional to the detected magnetic field is output to the signal processing circuit 4.
  • the voltage signal Vb output from the magnetosensitive element 3b is expressed by equation (2), where k is a proportional constant.
  • the magnetic field in the same direction as the sensitivity axis direction of the magnetosensitive element 3b is +, and the magnetic field in the opposite direction is-.
  • Vb k * ⁇ (B1-B3) -B ⁇ (2)
  • the signal processing circuit 4 performs arithmetic processing on the voltage signals Va and Vb output from the magnetic sensitive elements 3a and 3b. Specifically, as shown in FIG. 1B, when the magnetic sensitive elements 3a and 3b are arranged so that the sensitivity axis directions 32a and 32b are in the same direction, the signal processing circuit 4 includes the magnetic sensitive elements 3a and 3b. Is subtracted as shown in the equation (3) to calculate the current value of the main current I1 flowing through the main current path 21.
  • the external magnetic field B ⁇ is canceled by subtracting the voltage signals Va and Vb.
  • the influence of the external magnetic field B ⁇ can be eliminated, and the current value measurement accuracy can be improved.
  • the result of the expression (3) is also proportional to the measured current, and the signal processing circuit 4 determines the measured current (that is, the current path 2). It is possible to easily calculate the total current).
  • the signal processing circuit 4 adds the signals output from the magnetic sensitive elements 3a and 3b. Then, the current value may be calculated.
  • the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different. Composed.
  • a current is generated by using an induction magnetic field which is a difference between an induction magnetic field generated by the main current flowing through the main current path 21 and an induction magnetic field generated by the sub current flowing through the sub current paths 22 and 23.
  • the difference between the induced magnetic field is not generated by using the distance between the magnetosensitive element and the current path, but the difference is determined by the intensity difference of the induced magnetic field between the main current path and the sub current path.
  • the magnetic sensitive elements 3a and 3b may be arranged symmetrically with respect to the center of the main current path 21 between the main current path 21 and the sub current paths 22 and 23. High positional accuracy in mounting is not required. Further, the influence of the external magnetic field B ⁇ can be canceled by differential processing by the pair of magnetosensitive elements 3a and 3b. As a result, the current value measurement accuracy can be maintained and the current sensor 1 can be miniaturized without increasing the distance between the magnetosensitive element 3a and the magnetosensitive element 3b.
  • FIG. 3 is a schematic diagram showing the current sensor 1 of the present embodiment.
  • 3A is a top view of the current sensor 1
  • FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 3A.
  • the current sensor 1 includes a current path 2 in which slit-like openings 2a and 2b are formed in a plate-shaped conductor, and magnetosensitive elements 3a and 3b arranged in the openings 2a and 2b, respectively.
  • the current sensor 1 shown in FIG. 1 and the current sensor shown in FIG. 3 are common.
  • the difference between the current sensor 1 shown in FIG. 1 and the current sensor shown in FIG. 3 is the arrangement position of the magnetosensitive elements 3a and 3b due to the difference in the sensitivity axis direction of the magnetosensitive elements 3a and 3b.
  • the magnetic sensitive elements 3a and 3b are arranged in the direction in which the main current path 21 and the sub current paths 22 and 23 are arranged (X direction in FIG. 3B), and in the main current path 21 and the sub current path 22. They are arranged so as to have a sensitivity axis in a direction parallel to a direction (Z direction in FIG. 3B) orthogonal to a direction in which current flows (Y direction in FIG. 3B). That is, the magnetic sensitive elements 3a and 3b have sensitivity axis directions 32a and 32b, respectively.
  • X direction in FIG. 3B the direction in which the main current path 21 and the sub current paths 22 and 23 are arranged
  • the magnetic sensitive elements 3a and 3b are arranged so that the sensitivity axis directions 32a and 32b are in the same direction, but are arranged so that the sensitivity axis directions 32a and 32b are opposite to each other. Also good.
  • the magnetic sensitive elements 3a and 3b have sensitivity axis directions 32a and 32b in a direction orthogonal to the pair of main surfaces 31 like Hall elements. For this reason, it is preferable to arrange
  • the magnetic sensing elements 3a and 3b are configured such that the lower main surface 31, the upper surface 213 of the main current path 21, and the upper surfaces 222 and 223 of the sub current paths 22 and 23 are substantially in the same plane. You may arrange
  • the magnetic sensitive elements 3 a and 3 b may be arranged such that the side surfaces thereof are in contact with the side surface 211 of the main current path 21 and the side surfaces 221 and 231 of the sub current paths 22 and 23.
  • the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different.
  • a current is generated by using an induction magnetic field which is a difference between an induction magnetic field generated by the main current flowing through the main current path 21 and an induction magnetic field generated by the sub current flowing through the sub current paths 22 and 23.
  • the difference between the induced magnetic field is not generated by using the distance between the magnetosensitive element and the current path, but the difference is determined by the intensity difference of the induced magnetic field between the main current path and the sub current path. Since it is generated, it is not necessary to provide an extra space for difference generation.
  • the magnetic sensitive elements 3a and 3b may be arranged symmetrically with respect to the center of the main current path 21 between the main current path 21 and the sub current paths 22 and 23. High positional accuracy in mounting is not required. Further, the influence of the external magnetic field B ⁇ can be canceled by differential processing by the pair of magnetosensitive elements 3a and 3b. As a result, the current value measurement accuracy can be maintained and the current sensor 1 can be miniaturized without increasing the distance between the magnetosensitive element 3a and the magnetosensitive element 3b.
  • FIG. 4 is a schematic diagram showing the current sensor 1 of the present embodiment.
  • 4A is a top view of the current sensor 1
  • FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. 4A.
  • the current sensor 1 includes a current path 2 in which slit-like openings 2a and 2b are formed in a plate-shaped conductor, and magnetosensitive elements 3a and 3b arranged in the openings 2a and 2b, respectively.
  • the current sensor 1 shown in FIG. 1 and the current sensor shown in FIG. 4 are common.
  • the difference between the current sensor 1 shown in FIG. 1 and the current sensor shown in FIG. 4 is that the width of the main current path 21 is considerably smaller than the width of the sub current paths 22 and 23.
  • the magnetosensitive elements 3a and 3b detect the combined induction magnetic fields canceled by the induction magnetic fields B2 and B3 of the sub current paths 22 and 23, respectively.
  • the noise source is very far like geomagnetism, and the external magnetic field can be canceled by differential, not to mention that the external magnetic field affects the magnetic sensing elements 3a and 3b in parallel with the same intensity.
  • the external magnetic field generated by the noise source is substantially applied to the magnetosensitive elements 3a and 3b. It has the same effect and can be canceled by differential.
  • the distance between the magnetic sensing element 3a and the sub current path 23 is considerably smaller than that shown in FIG. 1B.
  • the magnetosensitive elements 3a and 3b are affected to the same extent by the induced magnetic field B3 of the sub current path 23.
  • Va k * ⁇ B1 + (B2 ⁇ B3 ′) + B ⁇ (1)
  • Vb k * ⁇ B1 + ( ⁇ B3 + B2 ′) + B ⁇ (2) ′
  • the width of the main current path 21 only needs to cancel the noise source in the vicinity of the main current path 21 and can be appropriately determined depending on the magnitude of the current to be measured, the type of the noise source in the vicinity of the main current path 21, and the like.
  • the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different.
  • the induced magnetic field is generated by using the induced magnetic field which is the difference between the induced magnetic field generated by the main current flowing through the main current path 21 and the induced magnetic field generated by the subcurrent flowing through the auxiliary current paths 22 and 23.
  • Current measurements can be made.
  • the distance between the magnetic sensing elements 3a and 3b can be further reduced by making the width of the main current path 21 smaller than the width of the sub current paths 22 and 23,
  • the current sensor 1 can be further downsized.
  • the influence of the noise source near the main current path here the adjacent current path, can be eliminated without reducing the signal of the current to be measured. The ratio can be improved.
  • FIG. 5 is a schematic diagram showing the current sensor 1 of the present embodiment.
  • 5A is a top view of the current sensor 1
  • FIG. 5B is a cross-sectional view taken along the line VB-VB in FIG. 5A.
  • the difference between the current sensor 1 shown in FIG. 1 and the current sensor 1 shown in FIG. 5 is the method of forming the openings 2a and 2b.
  • the current sensor 1 has a current path region R including a main current path 21 which is a flat conductor and a pair of sub current paths 22 and 23 which are flat conductors. At both ends of the current path 2 of the current sensor 1, the surface of the main current path 21 and the surfaces of the sub current paths 22 and 23 are connected. Further, in the region R formed of the central portion of the main current path 21 and the sub current paths 22 and 23, the main current path 21 and the sub current paths 22 and 23 are arranged with an interval.
  • the magnetosensitive elements 3a and 3b are arranged in the direction in which the main current path 21 and the sub current paths 22 and 23 are arranged (the X direction in FIG. 5B), and in the main current path 21 and the sub current path 22. They are arranged so as to have a sensitivity axis in a direction parallel to a direction (Z direction in FIG. 5B) orthogonal to a direction in which current flows (Y direction in FIG. 5B).
  • the magnetosensitive elements 3a and 3b detect the combined induction magnetic fields canceled by the induction magnetic fields B2 and B3 of the sub current paths 22 and 23, respectively.
  • the main current path 21 and the sub current paths 22 and 23 are configured by conductors having a rectangular cross section that is long in the height direction (Z direction) in a cross-sectional view.
  • the magnetic field B1 has more parallel components with respect to the side surface 211 of the main current path 21 than in the case shown in FIG. 1B. For this reason, compared with the case shown in FIG. 1B, the magnetic sensitive elements 3a and 3b can easily detect the induced magnetic field B1 of the main current path 2.
  • the width of the entire current path 2 including the main current path 21 and the sub current paths 22 and 23 can be further reduced, and the current sensor 1 can be reduced in size.
  • the current path 2 is formed by connecting the three conductors of the main current path 21 and the sub current paths 22 and 23, one current path 2 is branched into three current paths as shown in FIG. 1A. Compared to the case, it can be easily manufactured.
  • the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different.
  • a combined induction magnetic field that is a difference between the induction magnetic field generated by the main current flowing through the main current path 21 and the induction magnetic field generated by the sub current flowing through the sub current paths 22 and 23 is used. Current measurements can be made.
  • FIG. 6 is a diagram illustrating a modification of the present embodiment.
  • the current sensor 1 according to the present embodiment includes a main current path 21 made of a current line having a circular cross section and sub-current paths 22 and 23 made of a current line having a circular cross section. Also good.
  • the main current path 21 and the sub current paths 22, 23 are arranged at an interval in a region R formed of the central portion of the main current path 21 and the sub current paths 22, 23.
  • the main current path 21 and the sub current paths 22 and 23 are connected to each other at both ends of the main current path 21 and the sub current paths 22 and 23.
  • the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different.
  • a combined induction magnetic field that is a difference between the induction magnetic field generated by the main current flowing through the main current path 21 and the induction magnetic field generated by the sub current flowing through the sub current paths 22 and 23 is used. Current measurements can be made.
  • Embodiments 1 to 4 above can be implemented in combination as appropriate.
  • the arrangement, size, and the like of each component in the above embodiment can be changed as appropriate.
  • the present invention can be implemented with appropriate modifications without departing from the scope of the present invention.
  • the resistance values of the pair of sub current paths are made equal, and the resistance values of the pair of sub current paths are different from the resistance values of the main current path.
  • the present invention is not limited to this configuration.
  • the strength of the magnetic field generated by the pair of sub current paths is the same, the direction of the magnetic field is opposite, and the strength of the magnetic field generated by the main current path and the magnetic field generated by the sub current path are You may make it differ in strength.
  • the intensity of the magnetic field applied to the pair of magneto-sensitive elements by the main current path is different from the intensity of the magnetic field applied to the pair of magneto-sensitive elements by the sub current path. There is no end to it. Therefore, as in the first to fourth embodiments, a current sensor that can be miniaturized while maintaining the measurement accuracy of the current value can be realized.
  • the current sensor of the present invention can be used, for example, to detect the magnitude of a current for driving a motor of an electric vehicle or a hybrid car.

Abstract

An electric-current sensor in which a calculation process is performed on detection values of two magnetic sensing elements, whereby the effect of an external magnetic field is eliminated, wherein it is possible to make the sensor more compact without compromising the precision with which an electric-current value is measured. This electric-current sensor (1) is provided with an electric-current path (2) including a region (R) formed by a main electric-current path (21) and a pair of secondary electric-current paths (22, 23) arranged in parallel across a gap on either side of the main electric-current path (21), a pair of magnetic sensing elements (3a, 3b) provided between the main electric-current path (21) and each of the secondary electric-current paths (22, 23) in region (R), and a calculation circuit for calculating an electric-current value of the main electric-current path (21) on the basis of detection values from the pair of magnetic sensing elements (3a, 3b). The resistance values of the pair of secondary electric-current paths (22, 23) are equal, and the resistance value of the main electric-current path (21) is different from the resistance values of the pair of secondary electric-current paths (22, 23).

Description

電流センサCurrent sensor
　本発明は、外乱磁界の影響を排除して導体内を通流する電流を測定できる電流センサに関する。 The present invention relates to a current sensor that can measure the current flowing through a conductor while eliminating the influence of a disturbance magnetic field.
　電気自動車やハイブリッドカー等におけるモータ駆動技術分野では、比較的大きな電流が取り扱われるため、これら大電流を非接触で測定可能な電流センサが求められている。このような電流センサとして、被測定電流によって生じる磁界の変化を複数の磁気センサによって検出する電流センサが提案されている。このような電流センサとして、２つの感磁素子による検出値に対して差動処理を行い、外乱磁界の影響を排除する電流センサが提案されている。 In the field of motor drive technology in electric vehicles, hybrid cars, and the like, a relatively large current is handled, so a current sensor that can measure these large currents in a non-contact manner is required. As such a current sensor, a current sensor that detects a change in a magnetic field caused by a current to be measured by a plurality of magnetic sensors has been proposed. As such a current sensor, a current sensor has been proposed in which differential processing is performed on detection values obtained by two magnetosensitive elements to eliminate the influence of a disturbance magnetic field.
　かかる電流センサでは、電流路の中央部に開口部を形成して、第１及び第２の電流路の２つに分岐し、開口部において、第１の電流路の近傍に、当該第１の電流路を通流する電流による磁界を検出する第１の感磁素子を設け、第２の電流路の近傍に、当該第２の電流路を通流する電流による磁界を検出する第２の感磁素子を設けている。第１の感磁素子と第２の感磁素子とは外部磁界の影響を略等しく受ける。このため、第１の感磁素子の検出値と第２の感磁素子の検出値とに対して差動処理を行うことで、外部磁界の影響を排除しながら、第１の電流路及び第２の電流路を通流する電流値を測定することができる（例えば、特許文献１）。 In such a current sensor, an opening is formed in the central portion of the current path and branches into two of the first and second current paths. In the opening, the first current path is located in the vicinity of the first current path. A first magnetosensitive element for detecting a magnetic field due to a current flowing through the current path is provided, and a second sensitivity for detecting a magnetic field due to the current flowing through the second current path is provided in the vicinity of the second current path. A magnetic element is provided. The first magnetosensitive element and the second magnetosensitive element are almost equally affected by the external magnetic field. For this reason, differential processing is performed on the detected value of the first magnetosensitive element and the detected value of the second magnetosensitive element, thereby eliminating the influence of the external magnetic field and the first current path and the second The current value flowing through the two current paths can be measured (for example, Patent Document 1).
特開２００６－１８４２６９号公報JP 2006-184269 A
　しかしながら、上述の電流センサでは、第１の感磁素子と第１の電流路及び第２の電流路との間のそれぞれの距離が略等しいと、第１の電流路の磁界と第２の電流路の磁界とが相殺されてしまい、第１の感磁素子において第１の電流路の磁界を精度よく検出できない。同様に、第２の感磁素子と第１の電流路及び第２の電流路との間のそれぞれの距離が略等しいと、第１の電流路の磁界と第２の電流路の磁界とが相殺されてしまい、第２の感磁素子において第２の電流路の磁界を精度よく検出できない。 However, in the above-described current sensor, if the distances between the first magnetosensitive element and the first current path and the second current path are substantially equal, the magnetic field and the second current in the first current path The magnetic field of the path is canceled out, and the magnetic field of the first current path cannot be accurately detected in the first magnetosensitive element. Similarly, when the distances between the second magnetosensitive element and the first current path and the second current path are substantially equal, the magnetic field of the first current path and the magnetic field of the second current path are This cancels out, and the magnetic field in the second current path cannot be accurately detected in the second magnetosensitive element.
　このため、上述の電流センサでは、複数に分岐した電流路の磁界を精度よく検出するために、第１及び第２の感磁素子について、それぞれ、一方の電流路との距離を他方の電流路との距離よりも十分に小さくする必要がある。この結果、上述の電流センサでは、第１の電流路と第２の電流路との間に配置される第１の感磁素子と第２感磁素子との間の距離を大きくせざるを得ず、電流センサを小型化することができない。 For this reason, in the above-described current sensor, in order to accurately detect the magnetic field of the current path branched into a plurality, the distance from one current path is set to the other current path for each of the first and second magnetosensitive elements. It is necessary to make it sufficiently smaller than the distance. As a result, in the above-described current sensor, it is necessary to increase the distance between the first magnetosensitive element and the second magnetosensitive element arranged between the first current path and the second current path. Therefore, the current sensor cannot be reduced in size.
　このように、２つの感磁素子の検出値を減算するなどの演算処理を行うことで外部磁界の影響を排除する電流センサでは、複数に分岐した電流路の磁界を精度よく検出しようとすると、小型化することができないという問題点があった。 In this way, in a current sensor that eliminates the influence of an external magnetic field by performing arithmetic processing such as subtracting the detection values of two magnetosensitive elements, when trying to detect the magnetic field of a current path branched into a plurality accurately, There was a problem that it could not be miniaturized.
　本発明はかかる点に鑑みてなされたものであり、２つの感磁素子の検出値に対して演算処理を行うことで外部磁界の影響を排除する電流センサにおいて、電流の測定精度を維持しながら、小型化できる電流センサを提供することを目的とする。 The present invention has been made in view of such points, and in a current sensor that eliminates the influence of an external magnetic field by performing arithmetic processing on detection values of two magnetosensitive elements while maintaining current measurement accuracy. An object of the present invention is to provide a current sensor that can be miniaturized.
　本発明の電流センサは、主電流路、及び前記主電流路の両側に間隔をおいて平行に配置された一対の副電流路で構成された領域を含む電流路と、前記領域において、前記主電流路とそれぞれの副電流路との間に設けられた一対の感磁素子と、前記一対の感磁素子の検出値に基づいて前記主電流路の電流値を演算する演算回路と、を備え、前記一対の副電流路の抵抗値は等しく、前記主電流路の抵抗値は前記一対の副電流路の抵抗値と異なることを特徴とする。 The current sensor of the present invention includes a main current path and a current path including a region formed by a pair of sub current paths arranged in parallel at intervals on both sides of the main current path; A pair of magnetosensitive elements provided between the current path and each sub-current path, and an arithmetic circuit that calculates the current value of the main current path based on the detection value of the pair of magnetosensitive elements. The resistance values of the pair of sub current paths are equal, and the resistance values of the main current path are different from the resistance values of the pair of sub current paths.
　この構成によれば、主電流路の抵抗値は一対の副電流路の抵抗値と異なるので、測定対象の電流による誘導磁界が相殺されてしまうことが無い。このため、一対の感磁素子の検出値に基づいて電流値を演算することにより、外部磁界の影響を相殺することができるだけでなく、測定対象の電流による誘導磁界を感磁素子で確実に検出することができる。この結果、一対の感磁素子間の距離を大きくせずとも、電流路の電流値の測定精度を維持でき、電流センサを小型化できる。 According to this configuration, since the resistance value of the main current path is different from the resistance value of the pair of sub current paths, the induced magnetic field due to the current to be measured is not canceled out. For this reason, by calculating the current value based on the detection value of the pair of magnetosensitive elements, not only can the influence of the external magnetic field be canceled, but also the magnetosensitive element reliably detects the induced magnetic field due to the current to be measured. can do. As a result, the measurement accuracy of the current value of the current path can be maintained without increasing the distance between the pair of magnetosensitive elements, and the current sensor can be downsized.
　本発明の電流センサにおいては、前記一対の感磁素子は、前記領域の断面視において、前記主電流路の中心に対して対称となるようにそれぞれ設けられてもよい。 In the current sensor of the present invention, the pair of magnetosensitive elements may be provided so as to be symmetrical with respect to the center of the main current path in a sectional view of the region.
　本発明の電流センサにおいては、前記一対の感磁素子は、前記主電流路及び前記副電流路の並んでいる方向と、前記主電流路及び前記副電流路に電流が通流する方向とにそれぞれ直交する方向に平行な方向に感度軸を持つように配置されてもよい。この構成によれば、各感磁素子で検出される主電流路の磁界の向きと副電流路の磁界の向きとが逆向きとなり、互いの磁界が相殺されるので、主電流路で大電流が通流する場合でも、主電流路の電流値の測定精度を維持できる。 In the current sensor of the present invention, the pair of magnetosensitive elements includes a direction in which the main current path and the sub current path are arranged, and a direction in which current flows through the main current path and the sub current path. Each may be arranged so as to have a sensitivity axis in a direction parallel to the orthogonal direction. According to this configuration, the direction of the magnetic field in the main current path detected by each magneto-sensitive element and the direction of the magnetic field in the sub current path are reversed, and the mutual magnetic fields are offset. Even when current flows, the measurement accuracy of the current value in the main current path can be maintained.
　本発明の電流センサにおいては、前記主電流路と前記副電流路とは、それぞれ同じ材料で構成されており、前記領域の断面視における断面積が異なってもよい。この構成によれば、主電流路と副電流路とが同じ材料で構成できるので、より容易に電流センサを製造可能となる。 In the current sensor of the present invention, the main current path and the sub current path may be made of the same material, and the cross-sectional areas in the cross-sectional view of the region may be different. According to this configuration, since the main current path and the sub current path can be made of the same material, the current sensor can be manufactured more easily.
　本発明の電流センサにおいては、前記主電流路の幅は、前記副電流路の幅よりも狭くてもよい。この構成によれば、第１の感磁素子と第２の感磁素子との間の距離をより小さくすることができ、電流センサの小型化を図ることができるとともに、電流センサの近くにノイズ源のある外部磁場の影響も差動処理により効果的にキャンセルすることができ、測定精度を改善することができる。 In the current sensor of the present invention, the width of the main current path may be narrower than the width of the sub current path. According to this configuration, the distance between the first magnetosensitive element and the second magnetosensitive element can be further reduced, the current sensor can be reduced in size, and noise can be placed near the current sensor. The influence of the external magnetic field with the source can also be effectively canceled by the differential processing, and the measurement accuracy can be improved.
　本発明の電流センサにおいては、前記電流路が平板形状であり、前記領域は、前記主電流路及び前記副電流路に電流が通流する方向に平行な方向に形成された一対のスリットを前記電流路に形成することにより構成されてもよい。 In the current sensor of the present invention, the current path has a flat plate shape, and the region includes a pair of slits formed in a direction parallel to a direction in which current flows through the main current path and the sub current path. You may comprise by forming in an electric current path.
　本発明の電流センサにおいては、前記主電流路及び前記副電流路はそれぞれ平板形状であり、前記電流路は前記主電流路の面と前記副電流路の面とを連接させて構成されており、前記領域において、前記主電流路と前記副電流路とが間隔をおいて配置されてもよい。 In the current sensor of the present invention, each of the main current path and the sub current path has a flat plate shape, and the current path is configured by connecting the surface of the main current path and the surface of the sub current path. In the region, the main current path and the sub current path may be spaced apart.
　本発明の電流センサは、主電流路、及び前記主電流路の両側に間隔をおいて平行に配置された一対の副電流路で構成された領域を含む電流路と、前記領域において、前記主電流路とそれぞれの副電流路との間に設けられた一対の感磁素子と、前記一対の感磁素子の検出値に基づいて前記主電流路の電流値を演算する演算回路と、を備え、前記一対の副電流路が発生する磁界の強さは同一、かつ、磁界の向きが逆方向であり、前記主電流路が発生する磁界の強さと前記副電流路が発生する磁界の強さとが異なることを特徴とする。 The current sensor of the present invention includes a main current path and a current path including a region formed by a pair of sub current paths arranged in parallel at intervals on both sides of the main current path; A pair of magnetosensitive elements provided between the current path and each sub-current path, and an arithmetic circuit that calculates the current value of the main current path based on the detection value of the pair of magnetosensitive elements. The strength of the magnetic field generated by the pair of sub-current paths is the same and the direction of the magnetic field is opposite, the strength of the magnetic field generated by the main current path and the strength of the magnetic field generated by the sub-current path Are different.
　この構成によれば、主電流路が一対の感磁素子に与える磁界の強さと、副電流路が一対の感磁素子に与える磁界の強さが異なるので、測定対象の電流による誘導磁界が相殺されてしまうことが無い。このため、一対の感磁素子の検出値に基づいて電流値を演算することにより、外部磁界の影響を相殺することができるだけでなく、測定対象の電流による誘導磁界を感磁素子で確実に検出することができる。この結果、一対の感磁素子間の距離を大きくせずとも、電流路の電流値の測定精度を維持でき、電流センサを小型化できる。 According to this configuration, the intensity of the magnetic field applied to the pair of magnetosensitive elements by the main current path is different from the intensity of the magnetic field applied to the pair of magnetosensitive elements by the sub current path, so that the induced magnetic field due to the current to be measured cancels out. There is no end to it. For this reason, by calculating the current value based on the detection value of the pair of magnetosensitive elements, not only can the influence of the external magnetic field be canceled, but also the magnetosensitive element reliably detects the induced magnetic field due to the current to be measured. can do. As a result, the measurement accuracy of the current value of the current path can be maintained without increasing the distance between the pair of magnetosensitive elements, and the current sensor can be downsized.
　本発明によれば、２つの感磁素子の検出値に対して演算処理を行うことで外部磁界の影響を排除する電流センサにおいて、電流の測定精度を維持しながら、小型化できる電流センサを提供できる。 According to the present invention, in a current sensor that eliminates the influence of an external magnetic field by performing arithmetic processing on detection values of two magnetosensitive elements, a current sensor that can be reduced in size while maintaining current measurement accuracy is provided. it can.
実施の形態１に係る電流センサを示す模式図である。4 is a schematic diagram showing a current sensor according to Embodiment 1. FIG. 実施の形態１に係る電流センサの一例を示す回路図である。3 is a circuit diagram illustrating an example of a current sensor according to Embodiment 1. FIG. 実施の形態２に係る電流センサを示す模式図である。6 is a schematic diagram showing a current sensor according to Embodiment 2. FIG. 実施の形態３に係る電流センサを示す模式図である。6 is a schematic diagram showing a current sensor according to Embodiment 3. FIG. 実施の形態４に係る電流センサを示す模式図である。FIG. 6 is a schematic diagram showing a current sensor according to a fourth embodiment. 変形例に係る電流センサを示す模式図である。It is a schematic diagram which shows the current sensor which concerns on a modification.
　本発明者は、２つの感磁素子の検出値に対して差動処理を行うことで外部磁界の影響を排除する電流センサにおいて、外乱磁界の影響をキャンセルする際に、複数に分岐した電流路の磁界が相殺されないようにするためには、複数の電流路に電流が通流することにより発生する誘導磁界の間に差を設ける必要があることに着目した。そして、本発明者は、感磁素子と電流路との間の距離の調整により誘導磁界間に差を設けると小型化できないことに鑑みて、複数の電流路との間の抵抗値を異ならせることにより、誘導磁界間に差を設けることができることを見出し本発明をするに至った。 In the current sensor that eliminates the influence of the external magnetic field by performing differential processing on the detection values of the two magnetosensitive elements, the present inventor has a plurality of current paths branched when canceling the influence of the disturbance magnetic field. In order to prevent the magnetic fields from being canceled, it has been noted that it is necessary to provide a difference between the induced magnetic fields generated by the current flowing through the plurality of current paths. And this inventor makes resistance value between several electric current paths differ in view of not being able to reduce in size, if a difference is provided between induction magnetic fields by adjusting the distance between a magnetosensitive element and an electric current path. As a result, it was found that a difference can be provided between the induction magnetic fields, and the present invention has been achieved.
　すなわち、本発明の骨子は、２つの感磁素子の検出値を演算（差又は和を算出）することで外乱磁界の影響を除去するタイプの電流センサにおいて、主電流路、及び主電流路の両側に間隔をおいて平行に配置された一対の副電流路で構成された領域を含む電流路と、この領域において、電流路とそれぞれの副電流路との間に一対の感磁素子を設け、一対の副電流路の抵抗値を等しく、主電流路の抵抗値を一対の副電流路の抵抗値と異ならせることにより、電流の測定精度を維持しながら、小型化することである。以下、本発明の実施の形態について、図面を参照して詳細に説明する。 That is, the essence of the present invention is that the main current path and the main current path of the type of current sensor that eliminates the influence of the disturbance magnetic field by calculating (difference or sum) the detection values of the two magnetosensitive elements. A current path including a region composed of a pair of sub-current paths arranged in parallel at intervals on both sides, and in this region, a pair of magnetosensitive elements is provided between the current path and each sub-current path. The resistance value of the pair of sub current paths is made equal, and the resistance value of the main current path is made different from the resistance value of the pair of sub current paths, thereby reducing the size while maintaining the current measurement accuracy. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
（実施の形態１）
　本実施の形態では、本発明の電流センサ１の一例について説明する。図１は、本実施の形態の電流センサ１を示す模式図である。図１Ａは電流センサ１の上面図であり、図１Ｂは図１ＡにおけるＩＢ－ＩＢ線に沿う断面図である。図１Ａに示すように、電流センサ１は、平板形状の導体に一対の開口部２ａ、２ｂが形成された電流路２と、開口部２ａ、２ｂにそれぞれ配置される感磁素子３ａ、３ｂと、を備えている。 (Embodiment 1)
In the present embodiment, an example of the current sensor 1 of the present invention will be described. FIG. 1 is a schematic diagram showing a current sensor 1 of the present embodiment. 1A is a top view of the current sensor 1, and FIG. 1B is a cross-sectional view taken along line IB-IB in FIG. 1A. As shown in FIG. 1A, a current sensor 1 includes a current path 2 in which a pair of openings 2a and 2b are formed in a plate-shaped conductor, and magnetosensitive elements 3a and 3b disposed in the openings 2a and 2b, respectively. It is equipped with.
　図１Ａに示す電流センサ１において、一対の開口部２ａ、２ｂは、当該電流路２（特に主電流路及び副電流路）に電流が通流する方向に平行な方向に、当該電流路２に形成された一対のスリットである。電流路２に一対の開口部２ａ、２ｂを形成することにより、電流路２は、主電流路２１と主電流路２１の両側に開口部２ａ、２ｂを挟んで平行に配置された一対の副電流路２２、２３とに分岐する。主電流路２１と一対の副電流路２２、２３とで電流路の領域Ｒが構成される。すなわち、電流路２は、主電流路２１と、主電流路２１の両側に間隔をおいて平行に配置された副電流路２２、２３とで構成されている。電流路２を通流する電流は、主電流路２１を通流する電流（以下、主電流という）Ｉと、副電流路２２を通流する電流（以下、副電流という）Ｉ２と、副電流路２３を通流する電流（以下、副電流という）Ｉ３との３つに分流することになる。 In the current sensor 1 shown in FIG. 1A, the pair of openings 2a and 2b are connected to the current path 2 in a direction parallel to the direction in which current flows through the current path 2 (particularly the main current path and the sub current path). It is a pair of formed slits. By forming a pair of openings 2 a and 2 b in the current path 2, the current path 2 has a pair of sub-currents arranged in parallel with the openings 2 a and 2 b on both sides of the main current path 21 and the main current path 21. Branches to current paths 22 and 23. The main current path 21 and the pair of sub current paths 22 and 23 form a current path region R. That is, the current path 2 includes a main current path 21 and sub-current paths 22 and 23 that are arranged in parallel at intervals on both sides of the main current path 21. The current flowing through the current path 2 includes a current flowing through the main current path 21 (hereinafter referred to as main current) I, a current flowing through the sub current path 22 (hereinafter referred to as sub current) I2, and a sub current. The current is divided into three currents (hereinafter referred to as subcurrents) I3 flowing through the path 23.
　また、図１Ａに示す電流センサ１は、副電流路２２、２３の抵抗値が等しく、副電流路２２、２３の抵抗値と主電流路２１の抵抗値とが異なるように構成される。主電流路２１と副電流路２２、２３との間で抵抗値を異ならせる場合、主電流路２１の断面積と副電流路２２、２３の断面積とを異なるように構成してもよく、主電流路２１の材料と副電流路２２、２３の材料とを異なるようにしても良い。図１Ｂに示す電流センサ１においては、副電流路２２、２３の断面積を等しくし、副電流路２２、２３の断面積を主電流路２１の断面積よりも大きくしている。したがって、副電流路２２、２３を通流する副電流Ｉ２、Ｉ３の電流値を等しくし、主電流路２１を通流する主電流Ｉ１と副電流２２、２３を通流する副電流Ｉ２、Ｉ３の電流値を異ならせている（Ｉ１＞Ｉ２、Ｉ３またはＩ１＜Ｉ２、Ｉ３）。このため、主電流路２１が発生する磁界の強さと副電流路２３、２３が発生する磁界の強さとが異なる。なお、断面積は図１Ｂにおける幅（Ｘ方向）や厚さ（Ｚ方向）を変えることにより適宜調整する。このように断面積を変えることにより、電流センサ１を容易に製造することが可能となる。また、主電流路２１の材料と副電流路２２、２３の材料とを異ならせる場合には、主電流路２１の断面積と副電流路２２、２３の断面積とを等しくすることができる。 Further, the current sensor 1 shown in FIG. 1A is configured such that the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different. When the resistance value is different between the main current path 21 and the sub current paths 22 and 23, the cross sectional area of the main current path 21 and the cross section area of the sub current paths 22 and 23 may be different from each other. The material of the main current path 21 and the material of the sub current paths 22 and 23 may be different. In the current sensor 1 shown in FIG. 1B, the cross-sectional areas of the sub-current paths 22 and 23 are made equal, and the cross-sectional area of the sub-current paths 22 and 23 is made larger than the cross-sectional area of the main current path 21. Therefore, the current values of the subcurrents I2 and I3 flowing through the subcurrent paths 22 and 23 are equalized, and the main current I1 flowing through the main current path 21 and the subcurrents I2 and I3 flowing through the subcurrents 22 and 23 are equalized. Are different from each other (I1> I2, I3 or I1 <I2, I3). For this reason, the strength of the magnetic field generated by the main current path 21 is different from the strength of the magnetic field generated by the sub current paths 23 and 23. The cross-sectional area is appropriately adjusted by changing the width (X direction) and thickness (Z direction) in FIG. 1B. By changing the cross-sectional area in this way, the current sensor 1 can be easily manufactured. Further, when the material of the main current path 21 and the material of the sub current paths 22 and 23 are different, the cross sectional area of the main current path 21 and the cross sectional area of the sub current paths 22 and 23 can be made equal.
　主電流路２１の抵抗値と副電流路２２、２３の抵抗値とをどの程度異ならせるか、すなわち、主電流路２１に通流させる電流（主電流）と副電流路２２、２３に通流させる電流（副電流）とをどの程度異ならせるかについては、被測定電流Ｉ（＝Ｉ１＋Ｉ２＋Ｉ３）の大きさにより適宜設定することができる。したがって、被測定電流Ｉの大きさに応じて、主電流路２１及び副電流路２２、２３の抵抗値や材料を決定する。例えば、主電流Ｉ１の電流値と副電流Ｉ２、Ｉ３の電流値との差が小さくなるように主電流路２１及び副電流路２２、２３を構成することにより、主電流路２１の誘導磁界Ｂ１と副電流路２２、２３の誘導磁界Ｂ２、Ｂ３とが相殺する割合を大きくすることができるので、結果として被測定電流Ｉが数百Ａレベルの大電流である場合であっても、感磁素子３ａ、３ｂが磁気飽和することを防止して精度良く電流測定することができる。 How much the resistance value of the main current path 21 is different from the resistance value of the sub current paths 22, 23, that is, the current (main current) passed through the main current path 21 and the sub current paths 22, 23 The amount of current (subcurrent) to be varied can be set as appropriate depending on the magnitude of the current to be measured I (= I1 + I2 + I3). Therefore, the resistance values and materials of the main current path 21 and the sub current paths 22 and 23 are determined according to the magnitude of the current I to be measured. For example, by configuring the main current path 21 and the sub current paths 22 and 23 so as to reduce the difference between the current value of the main current I1 and the current values of the sub currents I2 and I3, the induced magnetic field B1 of the main current path 21 And the induced magnetic fields B2 and B3 of the auxiliary current paths 22 and 23 can be increased, so that even if the current I to be measured is a large current of several hundred A level, the magnetosensitive The elements 3a and 3b can be prevented from being magnetically saturated, and current can be measured accurately.
　また、図１Ａに示す領域Ｒの断面視において、主電流路２１とそれぞれの副電流路２２、２３との間に感磁素子３ａ、３ｂが設けられている。感磁素子３ａ、３ｂは、主電流路２１の中心に対して対称な位置に配置される。具体的には、図１Ｂに示すように、感磁素子３ａ、３ｂは、主電流路２１及び副電流路２２、２３の並んでいる方向（図１ＢにおけるＸ方向）と、主電流路２１及び副電流路２２に電流が通流する方向（図１ＢにおけるＹ方向）とにそれぞれ直交する方向（図１ＢにおけるＺ方向）に平行な方向に感度軸を持つように配置される。すなわち、感磁素子３ａ、３ｂは、それぞれ、感度軸方向３２ａ、３２ｂを有する。なお、図１Ｂでは、感磁素子３ａ、３ｂは、感度軸方向３２ａ、３２ｂが互いに同じ向きとなるように配置されているが、感度軸方向３２ａ、３２ｂが逆向きとなるように配置されてもよい。また、図１Ｂでは、感磁素子３ａ、３ｂは、その一対の主面３１に対して平行方向の感度軸方向３２ａ、３２ｂを有する。このため、主電流路２１の側面２１１、２１２に対して平行な向きの誘導磁界Ｂ１を検出し易いように、感磁素子３ａは、一方の主面３１が主電流路２１の側面２１１と接するように配置され、感磁素子３ｂは、一方の主面３１が主電流路２１の側面２１２と接するように配置される。なお、図示しないが、感磁素子３ａについては、副電流路２２の側面２２１に対して平行な向きの誘導磁界Ｂ２を検出し易いように、一方の主面３１が副電流路２２の側面２２１と接するように配置され、感磁素子３ｂについては、副電流路２３の側面２３１に対して平行な向きの誘導磁界Ｂ３を検出し易いように、一方の主面３１が副電流路２３の側面２３１と接するように配置されてもよい。なお、感度素子３ａ、３ｂの感度軸は、主電流路２１及び副電流路２２、２３の並んでいる方向（図１ＢにおけるＸ方向）と、主電流路２１及び副電流路２２に電流が通流する方向（図１ＢにおけるＹ方向）とにそれぞれ直交する方向（図１ＢにおけるＺ方向）に平行な方向である場合に感度が最大となるが、これに限られるものではない。例えば、感度素子３ａ、３ｂの感度軸は、図１ＢにおけるＹ－Ｚ平面（ただし、Ｙ方向を除く）上であり一対の感度素子３ａ、３ｂ間で互いに平行であれば、いずれの方向であってもよい。 Further, in the cross-sectional view of the region R shown in FIG. 1A, the magnetosensitive elements 3a and 3b are provided between the main current path 21 and the sub current paths 22 and 23, respectively. The magnetic sensitive elements 3 a and 3 b are arranged at positions symmetrical with respect to the center of the main current path 21. Specifically, as shown in FIG. 1B, the magnetosensitive elements 3a and 3b include a direction in which the main current path 21 and the sub current paths 22 and 23 are arranged (the X direction in FIG. 1B), the main current path 21 and They are arranged so as to have a sensitivity axis in a direction parallel to a direction (Z direction in FIG. 1B) orthogonal to a direction (Y direction in FIG. 1B) through which current flows in the sub current path 22. That is, the magnetic sensitive elements 3a and 3b have sensitivity axis directions 32a and 32b, respectively. In FIG. 1B, the magnetosensitive elements 3a and 3b are arranged so that the sensitivity axis directions 32a and 32b are in the same direction, but are arranged so that the sensitivity axis directions 32a and 32b are opposite to each other. Also good. In FIG. 1B, the magnetic sensitive elements 3 a and 3 b have sensitivity axis directions 32 a and 32 b parallel to the pair of main surfaces 31. For this reason, in order to easily detect the induced magnetic field B <b> 1 in a direction parallel to the side surfaces 211 and 212 of the main current path 21, the magnetic sensitive element 3 a has one main surface 31 in contact with the side surface 211 of the main current path 21. The magnetic sensitive element 3b is arranged such that one main surface 31 is in contact with the side surface 212 of the main current path 21. Although not shown, for the magnetic sensing element 3a, one main surface 31 is the side surface 221 of the sub-current path 22 so that the induced magnetic field B2 oriented parallel to the side surface 221 of the sub-current path 22 can be easily detected. For the magnetic sensing element 3b, one main surface 31 is a side surface of the sub-current path 23 so that the induced magnetic field B3 oriented parallel to the side surface 231 of the sub-current path 23 can be easily detected. 231 may be arranged so as to be in contact with 231. Note that the sensitivity axes of the sensitivity elements 3a and 3b are such that the current passes through the main current path 21 and the sub current paths 22 and 23 (the X direction in FIG. 1B) and the main current path 21 and the sub current path 22. The sensitivity is maximized when the direction is parallel to the direction (Z direction in FIG. 1B) perpendicular to the flowing direction (Y direction in FIG. 1B), but is not limited thereto. For example, the sensitivity axes of the sensitivity elements 3a and 3b are on the YZ plane (excluding the Y direction) in FIG. 1B and are in any direction as long as the pair of sensitivity elements 3a and 3b are parallel to each other. May be.
　図１Ｂに示すように、主電流路２１に主電流Ｉ１が流れると誘導磁界Ｂ１が発生し、副電流路２２及び２３に副電流Ｉ２及びＩ３が流れるとそれぞれ誘導磁界Ｂ２、Ｂ３が発生する。開口部２ａにおいて、主電流路２１の誘導磁界Ｂ１の向き（図１Ｂでは、下向き）と副電流路２２による誘導磁界Ｂ２の向き（図１Ｂでは、上向き）とは逆となるため、感磁素子３ａは、副電流路２２の誘導磁界Ｂ２により打ち消された合成誘導磁界ａ（Ｂ１－Ｂ２）を検出することになる。同様に、開口部２ｂにおいて、主電流路２１の誘導磁界Ｂ１の向き（図１Ｂでは、上向き）と副電流路２３の誘導磁界Ｂ３の向き（図１Ｂでは、下向き）とは逆となるため、感磁素子３ｂは、副電流路２３の誘導磁界Ｂ３により打ち消された合成誘導磁界ｂ（Ｂ１－Ｂ３）を検出することになる。 As shown in FIG. 1B, when the main current I1 flows through the main current path 21, an induction magnetic field B1 is generated, and when the subcurrents I2 and I3 flow through the sub current paths 22 and 23, induction magnetic fields B2 and B3 are generated, respectively. In the opening 2a, the direction of the induced magnetic field B1 in the main current path 21 (downward in FIG. 1B) is opposite to the direction of the induced magnetic field B2 in the subcurrent path 22 (upward in FIG. 1B). 3 a detects the combined induction magnetic field a (B 1 -B 2) canceled by the induction magnetic field B 2 of the auxiliary current path 22. Similarly, in the opening 2b, the direction of the induced magnetic field B1 in the main current path 21 (upward in FIG. 1B) is opposite to the direction of the induced magnetic field B3 in the subcurrent path 23 (downward in FIG. 1B). The magnetosensitive element 3b detects the combined induction magnetic field b (B1-B3) canceled by the induction magnetic field B3 of the sub current path 23.
　このように、感磁素子３ａ、３ｂは、それぞれ、副電流路２２、２３の誘導磁界Ｂ２、Ｂ３によって打ち消された合成誘導磁界を検出する。また、後で詳述するように、感磁素子３ａ、３ｂの感度軸方向３２ａ、３２ｂと平行な方向の外乱磁界は、感磁素子３ａ、３ｂの差動演算によりキャンセルすることができるので、外乱磁界の影響を排除することができる。 Thus, the magnetosensitive elements 3a and 3b detect the combined induction magnetic fields canceled by the induction magnetic fields B2 and B3 of the sub current paths 22 and 23, respectively. Further, as will be described in detail later, the disturbance magnetic field in the direction parallel to the sensitivity axis directions 32a and 32b of the magnetic sensitive elements 3a and 3b can be canceled by the differential operation of the magnetic sensitive elements 3a and 3b. The influence of the disturbance magnetic field can be eliminated.
　なお、感磁素子３ａ、３ｂとしては、例えば、ＧＭＲ（Ｇｉａｎｔ　Ｍａｇｎｅｔｏ　Ｒｅｓｉｓｔａｎｃｅ）素子やＴＭＲ（Ｔｕｎｎｅｌ　Ｍａｇｎｅｔｏ　Ｒｅｓｉｓｔａｎｃｅ）素子などの磁気抵抗効果素子や、ホール素子を用いた磁気センサなどを適用できる。この中で、磁気抵抗効果素子は、感磁素子３ａ、３ｂの一対の主面３１に対して平行方向の感度軸を有し、図１Ｂに示す配置においては電流路２の開口部２ａ、２ｂにおける電流路の側面に設けることで誘導磁界Ｂ１を検出することができるので、実装の容易さの点で好ましい。 In addition, as the magnetosensitive elements 3a and 3b, for example, a magnetoresistive element such as a GMR (Giant Magneto Resistance) element or a TMR (Tunnel Magneto Resistance) element, a magnetic sensor using a Hall element, or the like can be applied. Among them, the magnetoresistive effect element has a sensitivity axis parallel to the pair of main surfaces 31 of the magnetosensitive elements 3a and 3b. In the arrangement shown in FIG. 1B, the openings 2a and 2b of the current path 2 are arranged. Since the induced magnetic field B1 can be detected by providing it on the side surface of the current path, it is preferable in terms of ease of mounting.
　図２は、本発明に係る電流センサを示す回路図である。図２に示す電流センサは、一対の感磁素子３ａ、３ｂと、それぞれの感磁素子３ａ、３ｂからの検出結果を信号処理（電流値を演算）して出力する信号処理回路（演算回路）４とから構成されている。 FIG. 2 is a circuit diagram showing a current sensor according to the present invention. The current sensor shown in FIG. 2 is a signal processing circuit (arithmetic circuit) that outputs a pair of magnetic sensitive elements 3a and 3b and signal processing (current value is calculated) of detection results from the magnetic sensitive elements 3a and 3b. 4.
　感磁素子３ａは、副電流路２２の誘導磁界Ｂ２により打ち消された合成誘導磁界ａを検出し、検出した磁界に比例した大きさとなる電圧信号が信号処理回路４に出力される。例えば、図１Ｂに示す場合、地磁気などの外部磁界をＢαとすると、感磁素子３ａから出力される電圧信号Ｖａは、ｋを比例定数として（１）式で示される。なお感磁素子３ａの感度軸方向と同じ向きの磁界は＋、逆向きの磁界を－としている。
　　Ｖａ＝ｋ＊｛（－Ｂ１＋Ｂ２）－Ｂα｝　　　…（１） The magnetosensitive element 3 a detects the combined induction magnetic field a canceled by the induction magnetic field B 2 of the sub current path 22, and a voltage signal having a magnitude proportional to the detected magnetic field is output to the signal processing circuit 4. For example, in the case shown in FIG. 1B, assuming that an external magnetic field such as geomagnetism is Bα, the voltage signal Va output from the magnetosensitive element 3a is expressed by equation (1), where k is a proportional constant. The magnetic field in the same direction as the sensitivity axis direction of the magnetic sensing element 3a is +, and the magnetic field in the opposite direction is-.
Va = k * {(− B1 + B2) −Bα} (1)
　同様に、感磁素子３ｂは、副電流路２３の誘導磁界Ｂ３により打ち消された合成誘導磁界ｂを検出し、検出した磁界に比例した大きさとなる電圧信号が信号処理回路４に出力される。例えば、図１Ｂに示す場合、地磁気などの外部磁界をＢαとすると、感磁素子３ｂから出力される電圧信号Ｖｂは、ｋを比例定数として（２）式で示される。なお感磁素子３ｂの感度軸方向と同じ向きの磁界は＋、逆向きの磁界を－としている。
　　Ｖｂ＝ｋ＊｛（Ｂ１－Ｂ３）－Ｂα｝　　　…（２） Similarly, the magnetosensitive element 3 b detects the combined induction magnetic field b canceled by the induction magnetic field B 3 of the sub current path 23, and a voltage signal having a magnitude proportional to the detected magnetic field is output to the signal processing circuit 4. For example, in the case shown in FIG. 1B, assuming that an external magnetic field such as geomagnetism is Bα, the voltage signal Vb output from the magnetosensitive element 3b is expressed by equation (2), where k is a proportional constant. The magnetic field in the same direction as the sensitivity axis direction of the magnetosensitive element 3b is +, and the magnetic field in the opposite direction is-.
Vb = k * {(B1-B3) -Bα} (2)
　信号処理回路４は、感磁素子３ａ、３ｂから出力された電圧信号Ｖａ、Ｖｂに対して演算処理を行う。具体的には、図１Ｂに示すように、感度軸方向３２ａ、３２ｂが互いに同じ向きとなるように感磁素子３ａ、３ｂが配置される場合、信号処理回路４は、感磁素子３ａ、３ｂから出力された電圧信号Ｖａ、Ｖｂを（３）式に示すように減算して、主電流路２１を通流する主電流Ｉ１の電流値を算出する。
　　Ｖａ－Ｖｂ＝ｋ＊｛（－Ｂ１＋Ｂ２）－Ｂα｝－ｋ＊｛（Ｂ１－Ｂ３）－Ｂα｝
　　　　　　　＝ｋ＊｛－２Ｂ１＋Ｂ２－Ｂ３）｝　　　…（３）
　式（３）に示されるように、電圧信号Ｖａ、Ｖｂを減算することにより、外部磁界Ｂαが相殺される。この結果、外部磁界Ｂαの影響を排除でき、電流値の測定精度を向上させることができる。Ｂ１、Ｂ２、Ｂ３は全て、被測定電流Ｉ（＝Ｉ１＋Ｉ２＋Ｉ３）に比例するので、式（３）の結果も被測定電流に比例し、信号処理回路４にて被測定電流（すなわち、電流路２全体を通流する電流）を簡単に算出することができる。 The signal processing circuit 4 performs arithmetic processing on the voltage signals Va and Vb output from the magnetic sensitive elements 3a and 3b. Specifically, as shown in FIG. 1B, when the magnetic sensitive elements 3a and 3b are arranged so that the sensitivity axis directions 32a and 32b are in the same direction, the signal processing circuit 4 includes the magnetic sensitive elements 3a and 3b. Is subtracted as shown in the equation (3) to calculate the current value of the main current I1 flowing through the main current path 21.
Va−Vb = k * {(− B1 + B2) −Bα} −k * {(B1−B3) −Bα}
= K * {− 2B1 + B2−B3)} (3)
As shown in Expression (3), the external magnetic field Bα is canceled by subtracting the voltage signals Va and Vb. As a result, the influence of the external magnetic field Bα can be eliminated, and the current value measurement accuracy can be improved. Since B1, B2, and B3 are all proportional to the measured current I (= I1 + I2 + I3), the result of the expression (3) is also proportional to the measured current, and the signal processing circuit 4 determines the measured current (that is, the current path 2). It is possible to easily calculate the total current).
　なお、図示しないが、感度軸方向３２ａ、３２ｂが逆向きとなるように感磁素子３ａ、３ｂが配置される場合、信号処理回路４は、感磁素子３ａ、３ｂから出力された信号を加算して、電流値を算出してもよい。 Although not shown, when the magnetic sensitive elements 3a and 3b are arranged so that the sensitivity axis directions 32a and 32b are opposite, the signal processing circuit 4 adds the signals output from the magnetic sensitive elements 3a and 3b. Then, the current value may be calculated.
　以上のように、本実施の形態に係る電流センサ１は、副電流路２２、２３の抵抗値が等しく、副電流路２２、２３の抵抗値と主電流路２１の抵抗値とが異なるように構成される。このように構成しておくことにより、主電流路２１を通流する主電流により生じる誘導磁界と副電流路２２、２３を通流する副電流により生じる誘導磁界の差分の誘導磁界を用いて電流の測定を行うことができる。すなわち、この構成においては、感磁素子と電流路との間の距離を利用して誘導磁界の差分を生成するのではなく、主電流路と副電流路との誘導磁界の強度差で差分を生成しているので、差分生成のためのスペースを余分に設ける必要がない。また、この場合においては、主電流路２１とそれぞれの副電流路２２、２３との間に感磁素子３ａ、３ｂを主電流路２１の中心に対して対称な位置に配置すれば良いので、実装における高い位置精度は必要とされない。また、一対の感磁素子３ａ、３ｂによる差動処理により外部磁界Ｂαの影響を相殺することができる。この結果、感磁素子３ａと感磁素子３ｂとの間の距離を大きくせずとも、電流値の測定精度を維持でき、電流センサ１を小型化できる。 As described above, in the current sensor 1 according to the present embodiment, the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different. Composed. By configuring in this way, a current is generated by using an induction magnetic field which is a difference between an induction magnetic field generated by the main current flowing through the main current path 21 and an induction magnetic field generated by the sub current flowing through the sub current paths 22 and 23. Can be measured. That is, in this configuration, the difference between the induced magnetic field is not generated by using the distance between the magnetosensitive element and the current path, but the difference is determined by the intensity difference of the induced magnetic field between the main current path and the sub current path. Since it is generated, it is not necessary to provide an extra space for difference generation. In this case, the magnetic sensitive elements 3a and 3b may be arranged symmetrically with respect to the center of the main current path 21 between the main current path 21 and the sub current paths 22 and 23. High positional accuracy in mounting is not required. Further, the influence of the external magnetic field Bα can be canceled by differential processing by the pair of magnetosensitive elements 3a and 3b. As a result, the current value measurement accuracy can be maintained and the current sensor 1 can be miniaturized without increasing the distance between the magnetosensitive element 3a and the magnetosensitive element 3b.
（実施の形態２）
　本実施の形態では、本発明の電流センサ１の別の一例について説明する。図３は、本実施の形態の電流センサ１を示す模式図である。図３Ａは電流センサ１の上面図であり、図３Ｂは図３ＡにおけるIIIＢ－IIIＢ線に沿う断面図である。図３Ａに示すように、電流センサ１は、平板形状の導体にスリット状の開口部２ａ、２ｂが形成された電流路２と、開口部２ａ、２ｂにそれぞれ配置される感磁素子３ａ、３ｂと、を備えている。この点において、図１に示される電流センサ１と図３に示される電流センサとは共通する。図１に示される電流センサ１と図３に示される電流センサとの相違点は、感磁素子３ａ、３ｂの感度軸方向の違いに伴う感磁素子３ａ、３ｂの配置位置にある。 (Embodiment 2)
In the present embodiment, another example of the current sensor 1 of the present invention will be described. FIG. 3 is a schematic diagram showing the current sensor 1 of the present embodiment. 3A is a top view of the current sensor 1, and FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 3A. As shown in FIG. 3A, the current sensor 1 includes a current path 2 in which slit- like openings 2a and 2b are formed in a plate-shaped conductor, and magnetosensitive elements 3a and 3b arranged in the openings 2a and 2b, respectively. And. In this respect, the current sensor 1 shown in FIG. 1 and the current sensor shown in FIG. 3 are common. The difference between the current sensor 1 shown in FIG. 1 and the current sensor shown in FIG. 3 is the arrangement position of the magnetosensitive elements 3a and 3b due to the difference in the sensitivity axis direction of the magnetosensitive elements 3a and 3b.
　図３Ｂに示すように、感磁素子３ａ、３ｂは、主電流路２１及び副電流路２２、２３の並んでいる方向（図３ＢにおけるＸ方向）と、主電流路２１及び副電流路２２に電流が通流する方向（図３ＢにおけるＹ方向）とにそれぞれ直交する方向（図３ＢにおけるＺ方向）に平行な方向に感度軸を持つように配置される。すなわち、感磁素子３ａ、３ｂは、それぞれ、感度軸方向３２ａ、３２ｂを有する。なお、図３Ｂでは、感磁素子３ａ、３ｂは、感度軸方向３２ａ、３２ｂが互いに同じ向きとなるように配置されているが、感度軸方向３２ａ、３２ｂが逆向きとなるように配置されてもよい。また、図３Ｂでは、感磁素子３ａ、３ｂは、ホール素子のように、その一対の主面３１に対して直交する方向の感度軸方向３２ａ、３２ｂを有する。このため、感磁素子３ａ、３ｂの位置において、誘導磁界Ｂ１の前記感度軸方向成分がより大きくなるように配置されることが好ましい。例えば、図３Ｂに示すように、感磁素子３ａ、３ｂは、下側の主面３１と主電流路２１の上面２１３と副電流路２２、２３の上面２２２、２２３とがそれぞれ略同一平面となるように配置されてもよい。なお、図示しないが、感磁素子３ａ、３ｂは、その側面が主電流路２１の側面２１１や副電流路２２、２３の側面２２１、２３１と接するように配置されてもよい。 As shown in FIG. 3B, the magnetic sensitive elements 3a and 3b are arranged in the direction in which the main current path 21 and the sub current paths 22 and 23 are arranged (X direction in FIG. 3B), and in the main current path 21 and the sub current path 22. They are arranged so as to have a sensitivity axis in a direction parallel to a direction (Z direction in FIG. 3B) orthogonal to a direction in which current flows (Y direction in FIG. 3B). That is, the magnetic sensitive elements 3a and 3b have sensitivity axis directions 32a and 32b, respectively. In FIG. 3B, the magnetic sensitive elements 3a and 3b are arranged so that the sensitivity axis directions 32a and 32b are in the same direction, but are arranged so that the sensitivity axis directions 32a and 32b are opposite to each other. Also good. In FIG. 3B, the magnetic sensitive elements 3a and 3b have sensitivity axis directions 32a and 32b in a direction orthogonal to the pair of main surfaces 31 like Hall elements. For this reason, it is preferable to arrange | position so that the said sensitivity axial direction component of the induction magnetic field B1 may become larger in the position of the magnetic sensitive elements 3a and 3b. For example, as shown in FIG. 3B, the magnetic sensing elements 3a and 3b are configured such that the lower main surface 31, the upper surface 213 of the main current path 21, and the upper surfaces 222 and 223 of the sub current paths 22 and 23 are substantially in the same plane. You may arrange | position so that it may become. Although not shown, the magnetic sensitive elements 3 a and 3 b may be arranged such that the side surfaces thereof are in contact with the side surface 211 of the main current path 21 and the side surfaces 221 and 231 of the sub current paths 22 and 23.
　本実施の形態においても、副電流路２２、２３の抵抗値が等しく、副電流路２２、２３の抵抗値と主電流路２１の抵抗値とが異なるように構成される。このように構成しておくことにより、主電流路２１を通流する主電流により生じる誘導磁界と副電流路２２、２３を通流する副電流により生じる誘導磁界の差分の誘導磁界を用いて電流の測定を行うことができる。すなわち、この構成においては、感磁素子と電流路との間の距離を利用して誘導磁界の差分を生成するのではなく、主電流路と副電流路との誘導磁界の強度差で差分を生成しているので、差分生成のためのスペースを余分に設ける必要がない。また、この場合においては、主電流路２１とそれぞれの副電流路２２、２３との間に感磁素子３ａ、３ｂを主電流路２１の中心に対して対称な位置に配置すれば良いので、実装における高い位置精度は必要とされない。また、一対の感磁素子３ａ、３ｂによる差動処理により外部磁界Ｂαの影響を相殺することができる。この結果、感磁素子３ａと感磁素子３ｂとの間の距離を大きくせずとも、電流値の測定精度を維持でき、電流センサ１を小型化できる。 Also in the present embodiment, the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different. By configuring in this way, a current is generated by using an induction magnetic field which is a difference between an induction magnetic field generated by the main current flowing through the main current path 21 and an induction magnetic field generated by the sub current flowing through the sub current paths 22 and 23. Can be measured. That is, in this configuration, the difference between the induced magnetic field is not generated by using the distance between the magnetosensitive element and the current path, but the difference is determined by the intensity difference of the induced magnetic field between the main current path and the sub current path. Since it is generated, it is not necessary to provide an extra space for difference generation. In this case, the magnetic sensitive elements 3a and 3b may be arranged symmetrically with respect to the center of the main current path 21 between the main current path 21 and the sub current paths 22 and 23. High positional accuracy in mounting is not required. Further, the influence of the external magnetic field Bα can be canceled by differential processing by the pair of magnetosensitive elements 3a and 3b. As a result, the current value measurement accuracy can be maintained and the current sensor 1 can be miniaturized without increasing the distance between the magnetosensitive element 3a and the magnetosensitive element 3b.
（実施の形態３）
　本実施の形態では、本発明の電流センサ１の別の一例について説明する。図４は、本実施の形態の電流センサ１を示す模式図である。図４Ａは電流センサ１の上面図であり、図４Ｂは図４ＡにおけるIVＢ－IVＢ線に沿う断面図である。図４Ａに示すように、電流センサ１は、平板形状の導体にスリット状の開口部２ａ、２ｂが形成された電流路２と、開口部２ａ、２ｂにそれぞれ配置される感磁素子３ａ、３ｂと、を備えている。この点において、図１に示される電流センサ１と図４に示される電流センサとは共通する。図１に示される電流センサ１と図４に示される電流センサとの相違点は、主電流路２１の幅を副電流路２２、２３の幅に対してかなり小さくした点にある。 (Embodiment 3)
In the present embodiment, another example of the current sensor 1 of the present invention will be described. FIG. 4 is a schematic diagram showing the current sensor 1 of the present embodiment. 4A is a top view of the current sensor 1, and FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. 4A. As shown in FIG. 4A, the current sensor 1 includes a current path 2 in which slit- like openings 2a and 2b are formed in a plate-shaped conductor, and magnetosensitive elements 3a and 3b arranged in the openings 2a and 2b, respectively. And. In this respect, the current sensor 1 shown in FIG. 1 and the current sensor shown in FIG. 4 are common. The difference between the current sensor 1 shown in FIG. 1 and the current sensor shown in FIG. 4 is that the width of the main current path 21 is considerably smaller than the width of the sub current paths 22 and 23.
　感磁素子３ａ、３ｂは、主電流路２１及び副電流路２２、２３の並んでいる方向（図４ＢにおけるＸ方向）と、主電流路２１及び副電流路２２に電流が通流する方向（図４ＢにおけるＹ方向）とにそれぞれ直交する方向（図４ＢにおけるＺ方向）に平行な方向に感度軸を持つように配置される。図４Ｂにおいても、図１Ｂと同様に、感磁素子３ａ、３ｂは、それぞれ、副電流路２２、２３の誘導磁界Ｂ２、Ｂ３によって打ち消された合成誘導磁界を検出する。この構成では、地磁気のようにノイズ源が非常に遠く、外部磁場が感磁素子３ａ、３ｂに平行に同じ強度で影響するものは言うまでもなく差動によりキャンセルでき、加えて、主電流路２１の幅が小さい、すなわち感磁素子３ａ、３ｂの間の距離が近いことにより、電流路の近傍にノイズ源がある場合においても、そのノイズ源で発生した外部磁場が感磁素子３ａ、３ｂにほぼ等しく影響し、差動によりキャンセルできる特徴がある。 In the magnetic sensitive elements 3a and 3b, the direction in which the main current path 21 and the sub current paths 22 and 23 are arranged (the X direction in FIG. 4B) and the direction in which current flows through the main current path 21 and the sub current path 22 ( They are arranged so as to have a sensitivity axis in a direction parallel to a direction (Z direction in FIG. 4B) orthogonal to each other (Y direction in FIG. 4B). 4B, similarly to FIG. 1B, the magnetosensitive elements 3a and 3b detect the combined induction magnetic fields canceled by the induction magnetic fields B2 and B3 of the sub current paths 22 and 23, respectively. In this configuration, the noise source is very far like geomagnetism, and the external magnetic field can be canceled by differential, not to mention that the external magnetic field affects the magnetic sensing elements 3a and 3b in parallel with the same intensity. Even when there is a noise source in the vicinity of the current path due to the small width, that is, the distance between the magnetosensitive elements 3a and 3b, the external magnetic field generated by the noise source is substantially applied to the magnetosensitive elements 3a and 3b. It has the same effect and can be canceled by differential.
　ここで、図４Ｂに示す場合、感磁素子３ａと副電流路２３との間の距離は図１Ｂに示す場合と比較してかなり小さくなるため、感磁素子３ａ、３ｂは、副電流路２２の誘導磁界Ｂ２の影響を同程度に受けることになる。すなわち、副電流路２２及び感磁素子３ａの間の距離と、副電流路２２及び感磁素子３ｂの間の距離とが、誘導磁界を検出することに関して差が小さいと考えることできる。同様に、感磁素子３ａ、３ｂは、副電流路２３の誘導磁界Ｂ３の影響を同程度に受けることになる。すなわち、副電流路２３及び感磁素子３ａの間の距離と、副電流路２３及び感磁素子３ｂの間の距離とが、誘導磁界を検出することに関して差が小さいと考えることできる。これにより、副電流路２２および２３の誘導磁界Ｂ２、Ｂ３がそれぞれの感磁素子３ａ、３ｂの位置において相殺しあうため、主電流路２１の誘導磁界Ｂ１を打ち消す磁界（Ｂ２－Ｂ３’、－Ｂ３＋Ｂ２’）が小さくなる。したがって主電流路２１の幅が小さくなって電流Ｉ１は小さく誘導磁界Ｂ１が小さくてなっても、それを打ち消す磁界が小さいため、誘導磁界Ｂ１の強度を弱めることなく測定でき測定精度は低下することはない。この場合、式（１）（２）は次のようになる。
　　Ｖａ＝ｋ＊｛－Ｂ１＋（Ｂ２－Ｂ３’）＋Ｂα｝　　　…（１）’
　　Ｖｂ＝ｋ＊｛Ｂ１＋（－Ｂ３＋Ｂ２’）＋Ｂα｝　　　…（２）’
　なお、主電流路２１の幅は、主電流路２１近接のノイズ源をキャンセルできれば良く、被測定電流の大きさや、主電流路２１近接のノイズ源の種類等により適宜決定することができる。 Here, in the case shown in FIG. 4B, the distance between the magnetic sensing element 3a and the sub current path 23 is considerably smaller than that shown in FIG. 1B. Are affected to the same extent by the induced magnetic field B2. That is, it can be considered that the difference between the distance between the sub-current path 22 and the magnetic sensing element 3a and the distance between the sub-current path 22 and the magnetic sensing element 3b is small with respect to detecting the induced magnetic field. Similarly, the magnetosensitive elements 3a and 3b are affected to the same extent by the induced magnetic field B3 of the sub current path 23. That is, it can be considered that the difference between the distance between the sub current path 23 and the magnetic sensing element 3a and the distance between the sub current path 23 and the magnetic sensing element 3b is small with respect to detecting the induced magnetic field. As a result, the induced magnetic fields B2 and B3 of the sub-current paths 22 and 23 cancel each other at the positions of the respective magnetic sensing elements 3a and 3b, so that the magnetic fields (B2-B3 ′, − B3 + B2 ′) becomes smaller. Therefore, even if the width of the main current path 21 is reduced, the current I1 is small, and the induction magnetic field B1 is small, the magnetic field that cancels it is small. There is no. In this case, equations (1) and (2) are as follows.
Va = k * {− B1 + (B2−B3 ′) + Bα} (1) ′
Vb = k * {B1 + (− B3 + B2 ′) + Bα} (2) ′
The width of the main current path 21 only needs to cancel the noise source in the vicinity of the main current path 21 and can be appropriately determined depending on the magnitude of the current to be measured, the type of the noise source in the vicinity of the main current path 21, and the like.
　本実施の形態においても、副電流路２２、２３の抵抗値が等しく、副電流路２２、２３の抵抗値と主電流路２１の抵抗値とが異なるように構成される。このように構成しておくことにより、主電流路２１を通流する主電流により生じる誘導磁界と副電流路２２、２３を通流する副電流により生じる誘導磁界の差分の誘導磁界を用いて主電流の測定を行うことができる。また、本実施の形態の電流センサ１によれば、主電流路２１の幅を副電流路２２、２３の幅よりも小さくすることにより、感磁素子３ａ、３ｂ間の距離をより小さくでき、電流センサ１をより小型化することができる。さらに、本実施の形態の電流センサ１によれば、被測定電流の信号を低下させることなく、主電流路近傍のノイズ源、ここでは隣接電流路の影響を排除することができ、Ｓ／Ｎ比を向上することができる。 Also in the present embodiment, the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different. By configuring in this way, the induced magnetic field is generated by using the induced magnetic field which is the difference between the induced magnetic field generated by the main current flowing through the main current path 21 and the induced magnetic field generated by the subcurrent flowing through the auxiliary current paths 22 and 23. Current measurements can be made. Further, according to the current sensor 1 of the present embodiment, the distance between the magnetic sensing elements 3a and 3b can be further reduced by making the width of the main current path 21 smaller than the width of the sub current paths 22 and 23, The current sensor 1 can be further downsized. Furthermore, according to the current sensor 1 of the present embodiment, the influence of the noise source near the main current path, here the adjacent current path, can be eliminated without reducing the signal of the current to be measured. The ratio can be improved.
　なお、本実施の形態の構成は、上記実施の形態２にも同様に適用することが可能である。また、下記で説明する実施の形態４、５にもこの考え方を適用できる。 Note that the configuration of the present embodiment can be applied to the second embodiment as well. This concept can also be applied to Embodiments 4 and 5 described below.
（実施の形態４）
　本実施の形態では、本発明の電流センサ１の別の一例について説明する。図５は、本実施の形態の電流センサ１を示す模式図である。図５Ａは電流センサ１の上面図であり、図５Ｂは図５ＡにおけるＶＢ－ＶＢ線に沿う断面図である。図１に示される電流センサ１と図５に示される電流センサ１との相違点は、開口部２ａ、２ｂの形成方法である。 (Embodiment 4)
In the present embodiment, another example of the current sensor 1 of the present invention will be described. FIG. 5 is a schematic diagram showing the current sensor 1 of the present embodiment. 5A is a top view of the current sensor 1, and FIG. 5B is a cross-sectional view taken along the line VB-VB in FIG. 5A. The difference between the current sensor 1 shown in FIG. 1 and the current sensor 1 shown in FIG. 5 is the method of forming the openings 2a and 2b.
　図５Ａに示すように、電流センサ１は、平板形状の導体である主電流路２１と、平板形状の導体である一対の副電流路２２、２３とを含む電流路の領域Ｒを有する。電流センサ１の電流路２の両端部においては、主電流路２１の面と副電流路２２、２３の面とが連接させて構成される。また、主電流路２１と副電流路２２、２３の中央部からなる領域Ｒでは、主電流路２１と副電流路２２、２３とが間隔をおいて配置される。 As shown in FIG. 5A, the current sensor 1 has a current path region R including a main current path 21 which is a flat conductor and a pair of sub current paths 22 and 23 which are flat conductors. At both ends of the current path 2 of the current sensor 1, the surface of the main current path 21 and the surfaces of the sub current paths 22 and 23 are connected. Further, in the region R formed of the central portion of the main current path 21 and the sub current paths 22 and 23, the main current path 21 and the sub current paths 22 and 23 are arranged with an interval.
　図５Ｂに示すように、感磁素子３ａ、３ｂは、主電流路２１及び副電流路２２、２３の並んでいる方向（図５ＢにおけるＸ方向）と、主電流路２１及び副電流路２２に電流が通流する方向（図５ＢにおけるＹ方向）とにそれぞれ直交する方向（図５ＢにおけるＺ方向）に平行な方向に感度軸を持つように配置される。図５Ｂにおいても、図１Ｂと同様に、感磁素子３ａ、３ｂは、それぞれ、副電流路２２、２３の誘導磁界Ｂ２、Ｂ３によって打ち消された合成誘導磁界を検出する。 As shown in FIG. 5B, the magnetosensitive elements 3a and 3b are arranged in the direction in which the main current path 21 and the sub current paths 22 and 23 are arranged (the X direction in FIG. 5B), and in the main current path 21 and the sub current path 22. They are arranged so as to have a sensitivity axis in a direction parallel to a direction (Z direction in FIG. 5B) orthogonal to a direction in which current flows (Y direction in FIG. 5B). 5B, similarly to FIG. 1B, the magnetosensitive elements 3a and 3b detect the combined induction magnetic fields canceled by the induction magnetic fields B2 and B3 of the sub current paths 22 and 23, respectively.
　図５Ｂに示すように、主電流路２１、副電流路２２、２３は、断面視において、高さ方向（Ｚ方向）に長い断面矩形状の導体で構成されるため、主電流路２の誘導磁界Ｂ１は、主電流路２１の側面２１１に対する平行成分を図１Ｂに示す場合よりも多く有する。このため、図１Ｂに示す場合と比較して、感磁素子３ａ、３ｂは、主電流路２の誘導磁界Ｂ１を検出し易くなる。また、この構成によれば、主電流路２１、副電流路２２、２３を合わせた電流路２全体の幅をより小さくでき、電流センサ１の小型化を図ることができる。また、主電流路２１、副電流路２２、２３の３つの導体を連接することで電流路２が構成されるので、図１Ａに示すように１つの電流路２を３つの電流路に分岐させる場合と比較して、容易に製作することができる。 As shown in FIG. 5B, the main current path 21 and the sub current paths 22 and 23 are configured by conductors having a rectangular cross section that is long in the height direction (Z direction) in a cross-sectional view. The magnetic field B1 has more parallel components with respect to the side surface 211 of the main current path 21 than in the case shown in FIG. 1B. For this reason, compared with the case shown in FIG. 1B, the magnetic sensitive elements 3a and 3b can easily detect the induced magnetic field B1 of the main current path 2. Further, according to this configuration, the width of the entire current path 2 including the main current path 21 and the sub current paths 22 and 23 can be further reduced, and the current sensor 1 can be reduced in size. Further, since the current path 2 is formed by connecting the three conductors of the main current path 21 and the sub current paths 22 and 23, one current path 2 is branched into three current paths as shown in FIG. 1A. Compared to the case, it can be easily manufactured.
　本実施の形態においても、副電流路２２、２３の抵抗値が等しく、副電流路２２、２３の抵抗値と主電流路２１の抵抗値とが異なるように構成される。このように構成しておくことにより、主電流路２１を通流する主電流により生じる誘導磁界と副電流路２２、２３を通流する副電流により生じる誘導磁界の差分の合成誘導磁界を用いて電流の測定を行うことができる。 Also in the present embodiment, the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different. With this configuration, a combined induction magnetic field that is a difference between the induction magnetic field generated by the main current flowing through the main current path 21 and the induction magnetic field generated by the sub current flowing through the sub current paths 22 and 23 is used. Current measurements can be made.
　ここで、本実施の形態の変形例について図６を参照して説明する。図６は、本実施の形態の変形例を示す図である。図６に示すように、本実施の形態の電流センサ１は、断面円状の電流線からなる主電流路２１と、断面円状の電流線からなる副電流路２２、２３とで構成されてもよい。かかる電流センサ１の電流路２においては、主電流路２１と副電流路２２、２３の中央部からなる領域Ｒでは、主電流路２１と副電流路２２、２３とが間隔をおいて配置される。また、主電流路２１と副電流路２２、２３の両端部では、主電流路２１と副電流路２２、２３とを連接させて構成される。このような構成においても、副電流路２２、２３の抵抗値が等しく、副電流路２２、２３の抵抗値と主電流路２１の抵抗値とが異なるように構成される。このように構成しておくことにより、主電流路２１を通流する主電流により生じる誘導磁界と副電流路２２、２３を通流する副電流により生じる誘導磁界の差分の合成誘導磁界を用いて電流の測定を行うことができる。 Here, a modification of the present embodiment will be described with reference to FIG. FIG. 6 is a diagram illustrating a modification of the present embodiment. As shown in FIG. 6, the current sensor 1 according to the present embodiment includes a main current path 21 made of a current line having a circular cross section and sub-current paths 22 and 23 made of a current line having a circular cross section. Also good. In the current path 2 of the current sensor 1, the main current path 21 and the sub current paths 22, 23 are arranged at an interval in a region R formed of the central portion of the main current path 21 and the sub current paths 22, 23. The Further, the main current path 21 and the sub current paths 22 and 23 are connected to each other at both ends of the main current path 21 and the sub current paths 22 and 23. Even in such a configuration, the resistance values of the auxiliary current paths 22 and 23 are equal, and the resistance values of the auxiliary current paths 22 and 23 and the resistance value of the main current path 21 are different. With this configuration, a combined induction magnetic field that is a difference between the induction magnetic field generated by the main current flowing through the main current path 21 and the induction magnetic field generated by the sub current flowing through the sub current paths 22 and 23 is used. Current measurements can be made.
　なお、本発明は上記実施の形態に限定されず、種々変更して実施することができる。例えば、上記実施の形態１～４は、適宜組み合わせて実施することができる。以上のように、上記実施の形態における各構成要素の配置、大きさなどは適宜変更して実施することが可能である。その他、本発明は、本発明の範囲を逸脱しないで適宜変更して実施することができる。 Note that the present invention is not limited to the above embodiment, and can be implemented with various modifications. For example, Embodiments 1 to 4 above can be implemented in combination as appropriate. As described above, the arrangement, size, and the like of each component in the above embodiment can be changed as appropriate. In addition, the present invention can be implemented with appropriate modifications without departing from the scope of the present invention.
　例えば、上記実施の形態１～４においては、一対の副電流路の抵抗値を等しくし、この一対の副電流路の抵抗値と主電流路の抵抗値とを異ならせた例について説明したが、本発明は、この構成に限定されるものではない。本発明においては、一対の副電流路が発生する磁界の強さを同一とし、かつ、磁界の向きが逆方向であり、主電流路が発生する磁界の強さと副電流路が発生する磁界の強さとを異ならせるようにしてもよい。このような構成においても、主電流路が一対の感磁素子に与える磁界の強さと副電流路が一対の感磁素子に与える磁界の強さとが異なるので、測定対象の電流による誘導磁界が相殺されてしまうことが無い。したがって、上記実施の形態１～４と同様に、電流値の測定精度を維持しながら、小型化可能な電流センサを実現できる。 For example, in the above first to fourth embodiments, the resistance values of the pair of sub current paths are made equal, and the resistance values of the pair of sub current paths are different from the resistance values of the main current path. The present invention is not limited to this configuration. In the present invention, the strength of the magnetic field generated by the pair of sub current paths is the same, the direction of the magnetic field is opposite, and the strength of the magnetic field generated by the main current path and the magnetic field generated by the sub current path are You may make it differ in strength. Even in such a configuration, the intensity of the magnetic field applied to the pair of magneto-sensitive elements by the main current path is different from the intensity of the magnetic field applied to the pair of magneto-sensitive elements by the sub current path. There is no end to it. Therefore, as in the first to fourth embodiments, a current sensor that can be miniaturized while maintaining the measurement accuracy of the current value can be realized.
　本発明の電流センサは、例えば、電気自動車やハイブリッドカーのモータ駆動用の電流の大きさを検知するために用いることが可能である。 The current sensor of the present invention can be used, for example, to detect the magnitude of a current for driving a motor of an electric vehicle or a hybrid car.
　本出願は、２０１１年９月１３日出願の特願２０１１－１９９３４０に基づく。この内容は、すべてここに含めておく。 This application is based on Japanese Patent Application No. 2011-199340 filed on September 13, 2011. All this content is included here.

Claims (14)

  1. 　主電流路、及び前記主電流路の両側に間隔をおいて平行に配置された一対の副電流路で構成された領域を含む電流路と、
    　前記領域において、前記主電流路とそれぞれの副電流路との間に設けられた一対の感磁素子と、
    　前記一対の感磁素子の検出値に基づいて前記主電流路の電流値を演算する演算回路と、を備え、
    　前記一対の副電流路の抵抗値は等しく、前記主電流路の抵抗値は前記一対の副電流路の抵抗値と異なることを特徴とする電流センサ。     A current path including a main current path, and a region composed of a pair of sub current paths arranged in parallel at intervals on both sides of the main current path;
    In the region, a pair of magnetosensitive elements provided between the main current path and the respective sub current paths;
    An arithmetic circuit that calculates a current value of the main current path based on a detection value of the pair of magnetosensitive elements,
    The pair of sub current paths have the same resistance value, and the main current path has a different resistance value from the pair of sub current paths.
  2. 　前記一対の感磁素子は、前記領域の断面視において、前記主電流路の中心に対して対称となるようにそれぞれ設けられることを特徴とする請求項１に記載の電流センサ。 The current sensor according to claim 1, wherein the pair of magnetosensitive elements are provided so as to be symmetrical with respect to a center of the main current path in a cross-sectional view of the region.
  3. 　前記一対の感磁素子は、前記主電流路及び前記副電流路が並んでいる方向と、前記主電流路及び前記副電流路に電流が通流する方向とにそれぞれ直交する方向に平行な方向に感度軸を持つように配置されることを特徴とする請求項２に記載の電流センサ。 The pair of magnetosensitive elements are parallel to a direction orthogonal to a direction in which the main current path and the sub current path are aligned and a direction in which current flows through the main current path and the sub current path. The current sensor according to claim 2, wherein the current sensor is arranged so as to have a sensitivity axis.
  4. 　前記主電流路と前記副電流路とは、それぞれ同じ材料で構成されており、前記領域の断面視における断面積が異なることを特徴とする請求項１から請求項３のいずれかに記載の電流センサ。 The current according to any one of claims 1 to 3, wherein the main current path and the sub current path are made of the same material, and have different cross-sectional areas in a cross-sectional view of the region. Sensor.
  5. 　前記主電流路の幅は、前記副電流路の幅よりも狭いことを特徴とする請求項１から請求項４のいずれかに記載の電流センサ。 The current sensor according to any one of claims 1 to 4, wherein a width of the main current path is narrower than a width of the sub current path.
  6. 　前記電流路が平板形状であり、前記領域は、前記主電流路及び前記副電流路に電流が通流する方向に平行な方向に形成された一対のスリットを前記電流路に形成することにより構成されることを特徴とする請求項１から請求項５のいずれかに記載の電流センサ。 The current path has a flat plate shape, and the region is formed by forming a pair of slits formed in a direction parallel to a direction in which current flows in the main current path and the sub current path in the current path. The current sensor according to any one of claims 1 to 5, wherein the current sensor is provided.
  7. 　前記主電流路及び前記副電流路はそれぞれ平板形状であり、前記電流路は前記主電流路の面と前記副電流路の面とを連接させて構成されており、前記領域において、前記主電流路と前記副電流路とが間隔をおいて配置されることを特徴とする請求項１から請求項５のいずれかに記載の電流センサ。 Each of the main current path and the sub current path has a flat plate shape, and the current path is configured by connecting a surface of the main current path and a surface of the sub current path. The current sensor according to any one of claims 1 to 5, wherein a path and the sub current path are arranged with a space therebetween.
  8. 　主電流路、及び前記主電流路の両側に間隔をおいて平行に配置された一対の副電流路で構成された領域を含む電流路と、
    　前記領域において、前記主電流路とそれぞれの副電流路との間に設けられた一対の感磁素子と、
    　前記一対の感磁素子の検出値に基づいて前記主電流路の電流値を演算する演算回路と、を備え、
    　前記一対の副電流路が発生する磁界の強さは同一、かつ、磁界の向きが逆方向であり、
    　前記主電流路が発生する磁界の強さと、前記副電流路が発生する磁界の強さとが異なることを特徴とする電流センサ。     A current path including a main current path, and a region composed of a pair of sub current paths arranged in parallel at intervals on both sides of the main current path;
    In the region, a pair of magnetosensitive elements provided between the main current path and the respective sub current paths;
    An arithmetic circuit that calculates a current value of the main current path based on a detection value of the pair of magnetosensitive elements,
    The strength of the magnetic field generated by the pair of sub current paths is the same, and the direction of the magnetic field is opposite;
    The current sensor characterized in that the strength of the magnetic field generated by the main current path is different from the strength of the magnetic field generated by the sub current path.
  9. 　前記一対の感磁素子は、前記領域の断面視において、前記主電流路の中心に対して対称となるようにそれぞれ設けられることを特徴とする請求項８に記載の電流センサ。 9. The current sensor according to claim 8, wherein the pair of magnetosensitive elements are provided so as to be symmetric with respect to the center of the main current path in a sectional view of the region.
  10. 　前記一対の感磁素子は、前記主電流路及び前記副電流路の並んでいる方向と、前記主電流路及び前記副電流路に電流が通流する方向とにそれぞれ直交する方向に平行な方向に感度軸を持つように配置されることを特徴とする請求項９に記載の電流センサ。 The pair of magneto-sensitive elements are parallel to directions orthogonal to the direction in which the main current path and the sub current path are aligned and the direction in which current flows through the main current path and the sub current path, respectively. The current sensor according to claim 9, wherein the current sensor is arranged so as to have a sensitivity axis.
  11. 　前記主電流路と前記副電流路とは、それぞれ同じ材料で構成されており、前記領域の断面視における断面積が異なることを特徴とする請求項８から請求項１０のいずれかに記載の電流センサ。 11. The current according to claim 8, wherein the main current path and the sub current path are made of the same material, and have different cross-sectional areas in a sectional view of the region. Sensor.
  12. 　前記主電流路の幅は、前記副電流路の幅よりも狭いことを特徴とする請求項８から請求項１１のいずれかに記載の電流センサ。 The current sensor according to any one of claims 8 to 11, wherein a width of the main current path is narrower than a width of the sub current path.
  13. 　前記電流路が平板形状であり、前記領域は、前記主電流路及び前記副電流路に電流が通流する方向に平行な方向に形成された一対のスリットを前記電流路に形成することにより構成されることを特徴とする請求項８から請求項１２のいずれかに記載の電流センサ。 The current path has a flat plate shape, and the region is formed by forming a pair of slits formed in a direction parallel to a direction in which current flows in the main current path and the sub current path in the current path. The current sensor according to any one of claims 8 to 12, wherein:
  14. 　前記主電流路及び前記副電流路はそれぞれ平板形状であり、前記電流路は前記主電流路の面と前記副電流路の面とを連接させて構成されており、前記領域において、前記主電流路と前記副電流路とが間隔をおいて配置されることを特徴とする請求項８から請求項１２のいずれかに記載の電流センサ。 Each of the main current path and the sub current path has a flat plate shape, and the current path is configured by connecting a surface of the main current path and a surface of the sub current path. The current sensor according to any one of claims 8 to 12, wherein a path and the sub-current path are arranged at an interval.
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015089122A1 (en) * 2013-12-11 2015-06-18 Eaton Corporation Electrical current sensing apparatus
JP2015137894A (en) * 2014-01-21 2015-07-30 日立金属株式会社 current detection structure
JP2015137892A (en) * 2014-01-21 2015-07-30 日立金属株式会社 Current detection structure
WO2016002501A1 (en) * 2014-07-02 2016-01-07 株式会社村田製作所 Current sensor
WO2018021082A1 (en) * 2016-07-26 2018-02-01 株式会社デンソー Current sensor
DE102019114554B3 (en) * 2019-05-29 2020-09-24 Infineon Technologies Ag Power rail and power module with power rail

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5512497A (en) * 1978-07-11 1980-01-29 Westinghouse Electric Corp Electric current detection converter
JP2002202328A (en) * 2000-12-28 2002-07-19 Japan System Engineering Kk Magnetic field type current sensor
JP2006184269A (en) * 2004-12-02 2006-07-13 Yazaki Corp Current sensor
JP2008216230A (en) * 2007-03-02 2008-09-18 Koshin Denki Kk Current sensor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5512497A (en) * 1978-07-11 1980-01-29 Westinghouse Electric Corp Electric current detection converter
JP2002202328A (en) * 2000-12-28 2002-07-19 Japan System Engineering Kk Magnetic field type current sensor
JP2006184269A (en) * 2004-12-02 2006-07-13 Yazaki Corp Current sensor
JP2008216230A (en) * 2007-03-02 2008-09-18 Koshin Denki Kk Current sensor

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105981126A (en) * 2013-12-11 2016-09-28 伊顿公司 Electrical current sensing apparatus
CN105981126B (en) * 2013-12-11 2018-11-02 伊顿公司 Current sense device
US9746500B2 (en) 2013-12-11 2017-08-29 Eaton Corporation Electrical current sensing apparatus
WO2015089122A1 (en) * 2013-12-11 2015-06-18 Eaton Corporation Electrical current sensing apparatus
US9513317B2 (en) 2014-01-21 2016-12-06 Hitachi Metals, Ltd. Current detection structure
EP2899551A3 (en) * 2014-01-21 2015-08-12 Hitachi Metals, Ltd. Current detection structure
JP2015137892A (en) * 2014-01-21 2015-07-30 日立金属株式会社 Current detection structure
JP2015137894A (en) * 2014-01-21 2015-07-30 日立金属株式会社 current detection structure
WO2016002501A1 (en) * 2014-07-02 2016-01-07 株式会社村田製作所 Current sensor
JPWO2016002501A1 (en) * 2014-07-02 2017-04-27 株式会社村田製作所 Current sensor
WO2018021082A1 (en) * 2016-07-26 2018-02-01 株式会社デンソー Current sensor
DE102019114554B3 (en) * 2019-05-29 2020-09-24 Infineon Technologies Ag Power rail and power module with power rail
US11796571B2 (en) 2019-05-29 2023-10-24 Infineon Technologies Ag Busbar and power module with busbar

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