WO2016009807A1 - Capteur de courant - Google Patents

Capteur de courant Download PDF

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Publication number
WO2016009807A1
WO2016009807A1 PCT/JP2015/068327 JP2015068327W WO2016009807A1 WO 2016009807 A1 WO2016009807 A1 WO 2016009807A1 JP 2015068327 W JP2015068327 W JP 2015068327W WO 2016009807 A1 WO2016009807 A1 WO 2016009807A1
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WO
WIPO (PCT)
Prior art keywords
flat plate
plate portion
magnetic
sensor
magnetic sensor
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Application number
PCT/JP2015/068327
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English (en)
Japanese (ja)
Inventor
川浪　崇
Original Assignee
株式会社村田製作所
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Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Priority to JP2016534348A priority Critical patent/JP6304380B2/ja
Publication of WO2016009807A1 publication Critical patent/WO2016009807A1/fr

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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

Definitions

  • the present invention relates to a current sensor, and more particularly to a current sensor that measures the value of a current to be measured by detecting a magnetic field generated according to the current to be measured.
  • Patent Document 1 discloses a sensor chip in which an output signal is proportional to a current to be measured and is not easily disturbed by temperature and an external magnetic field and aims to maintain a stable sensitivity.
  • the sensor chip described in Patent Document 1 is provided with a Wheatstone bridge type bridge circuit for measuring the gradient of the magnetic field strength.
  • the sensor chip has first to fourth magnetic sensitive resistors arranged in first and second ranges spaced from the central axis.
  • the first magnetic sensitive resistor and the second magnetic sensitive resistor are connected in series to form a first bridge shunt, and the third magnetic sensitive resistor and the fourth magnetic sensitive resistor are connected in series. Forming a second bridge shunt.
  • the first and fourth magnetic sensitive resistors are arranged in the first range
  • the second and third magnetic sensitive resistors are arranged in the second range
  • the first and fourth magnetic sensitive resistors and the second and third magnetic sensitive resistors arranged in the second range are arranged symmetrically with respect to the central axis.
  • JP-A-2013-011469 Patent Document 2
  • JP-A-2010-008050 Patent Document 3
  • Patent Document 3 JP-A-2010-008050
  • the current sensor described in Patent Document 2 has a magnetoelectric conversion element formed on one surface of a sensor substrate, and a magnetic shield portion surrounding each of the sensor substrate and the conductor to be measured.
  • the current sensor described in Patent Literature 3 includes a primary conductor, a magnetic detection element fixedly arranged with respect to the primary conductor so as to detect a magnetic field generated by a current flowing through the primary conductor, and a magnetic detection element. And a magnetic shield body for magnetic shielding.
  • the magnetic shield body has an annular enclosure that encloses the primary conductor and the magnetic detection element inside.
  • the strength of the magnetic field detected by each of the first to fourth magnetic sensitive resistors is inversely proportional to the square of the distance from the primary conductor. For this reason, it is necessary to accurately arrange the first to fourth magnetic sensitive resistors at desired positions with respect to the primary conductor, and it is difficult to manufacture the sensor chip.
  • An external magnetic field having a strength inversely proportional to the square of is applied.
  • the external magnetic field in the first and fourth magnetic sensitive resistors arranged in the first range and the second and third magnetic sensitive resistors arranged in the second range Since the distance from the source is different, the external magnetic field generated from the external magnetic field source affects the output signal of the sensor chip.
  • the present invention has been made in view of the above problems, and an object thereof is to provide a current sensor that can reduce the influence of an external magnetic field and can be easily manufactured.
  • the current sensor includes a primary conductor through which a current to be measured flows, a first magnetic sensor for detecting the strength of a magnetic field generated by the current flowing through the primary conductor, and a primary conductor spaced apart from each other. And a magnetic body surrounding the primary conductor.
  • the primary conductor includes a first flat plate portion and a second flat plate portion that face each other with a gap therebetween. The first flat plate portion and the second flat plate portion are electrically connected to each other in series, and the currents flow in opposite directions.
  • the first magnetic sensor is located in a region surrounded by the magnetic body.
  • the first magnetic sensor is disposed between the first flat plate portion and the second flat plate portion so as to detect a magnetic field in a direction orthogonal to the direction in which the first flat plate portion and the second flat plate portion are arranged.
  • the current sensor further includes a second magnetic sensor that detects the strength of the magnetic field generated by the current flowing through the primary conductor.
  • the primary conductor further includes a third flat plate portion that is positioned on the opposite side of the first flat plate portion with a distance from the second flat plate portion and that faces the second flat plate portion.
  • the third flat plate portion and the second flat plate portion are electrically connected to each other in series, and the currents flow in opposite directions.
  • the second magnetic sensor is located in a region surrounded by the magnetic body.
  • the second magnetic sensor is disposed between the second flat plate portion and the third flat plate portion so as to detect a magnetic field in a direction orthogonal to the direction in which the second flat plate portion and the third flat plate portion are arranged.
  • the current sensor further includes a calculation unit that calculates the value of the current by calculating the detection value of the first magnetic sensor and the detection value of the second magnetic sensor. Regarding the strength of the magnetic field generated by the current flowing through the primary conductor, the phase of the detection value of the first magnetic sensor and the phase of the detection value of the second magnetic sensor are opposite in phase.
  • the calculation unit is a subtractor or a differential amplifier.
  • the current sensor further includes a calculation unit that calculates the value of the current by calculating the detection value of the first magnetic sensor and the detection value of the second magnetic sensor. Regarding the strength of the magnetic field generated by the current flowing through the primary conductor, the phase of the detection value of the first magnetic sensor and the phase of the detection value of the second magnetic sensor are in phase.
  • the calculation unit is an adder or a summing amplifier.
  • the primary conductor further includes a pair of side wall portions that respectively connect the first flat plate portion and the third flat plate portion.
  • the second flat plate portion is spaced from the cylindrical portion on the inner side of the cylindrical portion so as to be coaxial with the cylindrical portion constituted by the first flat plate portion, the third flat plate portion, and the pair of side wall portions. Position it.
  • the primary conductor further includes a connecting portion that connects the second flat plate portion and the cylindrical portion.
  • the primary conductor includes a first connecting portion that connects the end portion of the first flat plate portion and one end of the second flat plate portion, and the other end of the second flat plate portion and the end of the third flat plate portion. It further includes a second connecting part that connects the parts.
  • the direction in which the current flows through the first connecting portion is the same as the direction in which the current flows through the second connecting portion.
  • a current sensor that can reduce the influence of an external magnetic field can be easily manufactured.
  • FIG. 2 is a cross-sectional view of the current sensor of FIG. 1 viewed from the direction of arrows II-II.
  • FIG. 3 is a cross-sectional view of the current sensor of FIG. 2 as viewed from the direction of arrows III-III.
  • It is a perspective view which shows the state which connects the primary conductor and external wiring of the current sensor which concern on Embodiment 1 of this invention.
  • It is a top view which shows the shape of the primary conductor with which the current sensor which concerns on a 1st comparative example is provided.
  • FIG. 6 is a contour map showing the result of simulating the magnetic flux density of the magnetic field generated around the primary conductor of the current sensor according to the first comparative example, as seen in the section taken along the line VI-VI in FIG.
  • FIG. 10 is a graph showing the relationship between the distance away from the central portion of the second flat plate portion in the left-right direction in FIG. 9 in the up-down direction in FIG. 9 and the magnetic flux density in the current sensor according to Embodiment 1 of the present invention. It is a perspective view which shows the structure of the current sensor which concerns on Embodiment 2 of this invention.
  • FIG. 12 is a cross-sectional view of the current sensor of FIG. 11 as viewed from the direction of arrows XII-XII.
  • FIG. 13 is a diagram schematically showing a generated magnetic field in a cross-sectional view of the current sensor according to the second embodiment of the present invention as viewed from the direction of the arrow XIII-XIII in FIG.
  • It is a magnetic flux diagram which shows the result of having simulated the magnetic flux density of the magnetic field which generate
  • FIG. 14 is a graph showing the relationship between the distance away from the center of the second flat plate portion 212 in the left-right direction in FIG. 13 in the up-down direction in FIG. 13 and the magnetic flux density in the current sensor according to Embodiment 2 of the present invention. .
  • FIG. 1 is a perspective view showing a configuration of a current sensor according to Embodiment 1 of the present invention.
  • 2 is a cross-sectional view of the current sensor of FIG. 1 as viewed from the direction of arrows II-II.
  • 3 is a cross-sectional view of the current sensor of FIG. 2 as viewed from the direction of arrows III-III.
  • FIG. 4 is a perspective view showing a state in which the primary conductor and the external wiring of the current sensor according to the present embodiment are connected.
  • the center point 112c of the 2nd flat plate part 112 is shown in figure.
  • the current sensor 100 according to the first embodiment of the present invention includes a primary conductor 110 through which a current to be measured flows.
  • the current sensor 100 includes a first magnetic sensor 120 and a second magnetic sensor 121 that detect the strength of the magnetic field generated by the current flowing through the primary conductor 110 with an odd function input / output characteristic.
  • the current sensor 100 includes two magnetic sensors.
  • the current sensor 100 may include at least one magnetic sensor.
  • the current sensor 100 includes a magnetic body 160 that surrounds the primary conductor 110 at an interval from the primary conductor 110.
  • the current sensor 100 includes a subtractor 130 that is a calculation unit that calculates the value of the current by subtracting the detection value of the first magnetic sensor 120 and the detection value of the second magnetic sensor 121.
  • the primary conductor 110 includes a first flat plate portion 111a and a second flat plate portion 112 that are opposed to each other with a space therebetween.
  • the 1st flat plate part 111a and the 2nd flat plate part 112 are located in parallel with each other.
  • the primary conductor 110 includes a third flat plate portion 111b that is located on the opposite side of the first flat plate portion 111a with a space from the second flat plate portion 112 and that faces the second flat plate portion 112.
  • the second flat plate portion 112 and the third flat plate portion 111b are positioned in parallel to each other.
  • the 1st flat plate part 111a, the 2nd flat plate part 112, and the 3rd flat plate part 111b are arrange
  • the distance dimension G 1 between the first flat plate portion 111a and the second flat plate portion 112 is equal to the distance size G 2 between the second flat plate portion 112 and the third flat plate portion 111b.
  • the distance dimension G 1 between the first flat plate portion 111a and the second flat plate portion 112 is different from the distance size G 2 between the second flat plate portion 112 and the third flat plate portion 111b. May be.
  • the primary conductor 110 includes a side wall portion 111c and a side wall portion 111d that connect the first flat plate portion 111a and the third flat plate portion 111b, respectively.
  • the side wall part 111c and the side wall part 111d are located in parallel to each other.
  • the primary conductor 110 includes a connecting portion 113 that connects the cylindrical portion 111 constituted by the first flat plate portion 111a, the third flat plate portion 111b, and the pair of side wall portions 111c and 111d and the second flat plate portion 112. .
  • the cylindrical portion 111 extends around the second flat plate portion 112 with an interval from the second flat plate portion 112. Specifically, the cylindrical part 111 has a cylindrical shape having openings at both ends. In the present embodiment, the cylindrical portion 111 has a rectangular outer shape in cross section, but the shape of the cylindrical portion 111 is not limited to this.
  • the connecting portion 113 connects the cylindrical portion 111 and the second flat plate portion 112 continuously with one end of the second flat plate portion 112 while being positioned so as to close one opening of the cylindrical portion 111.
  • the connection portion 113 has a rectangular outer shape that is continuous with the inner surface of the cylindrical portion 111, but the shape of the connection portion 113 is not limited to this.
  • the second flat plate portion 112 extends at an interval from the tubular portion 111 inside the tubular portion 111 so as to be positioned coaxially with the tubular portion 111.
  • the second flat plate portion 112 has a flat plate-like outer shape facing each of the first flat plate portion 111a and the third flat plate portion 111b in parallel. The shape is not limited to this.
  • the length of the second flat plate portion 212 is slightly shorter than the length of the cylindrical portion 111.
  • the cylindrical portion 111 and the second flat plate portion 112 are electrically connected to each other in series.
  • the width dimension H of the second flat plate portion 112 is between the adjacent flat plate portions. It is 1.5 times or more of the maximum value of the distances G 1 and G 2 between them. Further, the length dimension Le of the second flat plate portion 112 shown in FIG. 2 is equal to or larger than the width size H of the second flat plate portion 112.
  • the shape of the primary conductor 110 is not limited to the above.
  • the primary conductor 110 may not include the side wall portion 111c and the side wall portion 111d.
  • the primary conductor 110 has an E-shape when viewed in plan.
  • the primary conductor 110 is made of aluminum.
  • the material of the primary conductor 110 is not limited to this, and may be a metal such as silver or copper, or an alloy containing these metals.
  • the primary conductor 110 may be subjected to a surface treatment.
  • a surface treatment For example, at least one plating layer made of a metal such as nickel, tin, silver, copper, or an alloy containing these metals may be provided on the surface of the primary conductor 110.
  • the primary conductor 110 is integrally formed by cutting a square columnar block.
  • the method of forming the primary conductor 110 is not limited to this, and the primary conductor 110 may be formed by a method such as casting, forging, or pressing.
  • the direction 11 in which the current flows through the cylindrical portion 111 is opposite to the direction 12 in which the current flows through the second flat plate portion 112. Therefore, the direction 11 in which the current flows through the first flat plate portion 111a, the direction 11 in which the current flows through the third flat plate portion 111b, and the direction 12 in which the current flows through the second flat plate portion 112 are opposite.
  • the external wiring includes an input wiring 170 having an input terminal, an output wiring 171 having an output terminal, and a bent plate-like connection conductor 172.
  • the input terminal of the input wiring 170 and the output terminal of the output wiring 171 each have an annular portion.
  • a first through hole 173 for connecting the input wiring 170 to the connection conductor 172 is provided at the center of the connection conductor 172.
  • second through holes 174 for connecting the connection conductor 172 to the cylindrical portion 111 are provided. In the connection conductor 172, both ends and the center are bent so as to be positioned on two parallel planes.
  • Two first female threads 111 s are provided at the opening end of the cylindrical portion 111.
  • the two first female screws 111 s are located on the opposite sides in the radial direction of the cylindrical portion 111.
  • Each of the two first female threads 111 s extends in parallel with the central axis direction of the cylindrical portion 111.
  • a bolt 190 is inserted into the annular portion of the input terminal of the input wiring 170 and the first through hole 173 of the connection conductor 172, and the bolt 190 and the nut 180 are fastened, whereby the input wiring 170 and the connection conductor 172 are connected. And are connected.
  • the cylindrical part 111 and the connection conductor 172 are connected by inserting the bolt 190 in each 2nd through-hole 174 of the connection conductor 172, and fastening these bolts 190 and the 1st internal thread 111s, respectively.
  • the bolt 190 is inserted into the annular portion of the output terminal of the output wiring 171 and the bolt 190 and the second female screw 112s are fastened, whereby the second flat plate portion 112 and the output wiring 171 are connected.
  • the current input to the cylindrical portion 111 flows from the outside toward the center through the connecting portion 113 and is output from the second flat plate portion 112.
  • connection method of the primary conductor 110 and the external wiring is not limited to the above, and the connection direction is such that the direction in which the current flows through the cylindrical portion 111 is opposite to the direction in which the current flows through the second flat plate portion 112. Just do it. Therefore, the cylindrical part 111 may be connected to the output wiring, and the second flat plate part 112 may be connected to the input wiring.
  • the first magnetic sensor 120 and the second magnetic sensor 121 are positioned side by side so as to sandwich the second flat plate portion 112 between each other inside the cylindrical portion 111.
  • each of the first magnetic sensor 120 and the second magnetic sensor 121 is located at an interval with respect to both the cylindrical portion 111 and the second flat plate portion 112.
  • the first magnetic sensor 120 is located between the first flat plate portion 111 a and the second flat plate portion 112.
  • the second magnetic sensor 121 is located between the second flat plate portion 112 and the third flat plate portion 111b.
  • Each of the first magnetic sensor 120 and the second magnetic sensor 121 is located in a region surrounded by the magnetic body 160.
  • Each of the first magnetic sensor 120 and the second magnetic sensor 121 is in a direction orthogonal to the direction in which the first magnetic sensor 120 and the second magnetic sensor 121 are aligned and in the extending direction of the second flat plate portion 112. And has a detection axis in the orthogonal direction.
  • the first magnetic sensor 120 has a detection axis in the direction indicated by the arrow 120a in FIG.
  • the second magnetic sensor 121 has a detection axis in the direction indicated by the arrow 121a in FIG.
  • the first magnetic sensor 120 can detect a magnetic field in a direction orthogonal to the direction in which the first flat plate portion 111a and the second flat plate portion 112 are arranged.
  • the second magnetic sensor 121 can detect a magnetic field in a direction orthogonal to the direction in which the second flat plate portion 112 and the third flat plate portion 111b are arranged.
  • the first magnetic sensor 120 and the second magnetic sensor 121 output a positive value when a magnetic field directed in one direction of the detection axis is detected, and a magnetic field directed in a direction opposite to the one direction of the detection axis. It has an odd function input / output characteristic that outputs a negative value when detected. That is, with respect to the strength of the magnetic field generated by the current flowing through the primary conductor 110, the phase of the detection value of the first magnetic sensor 120 and the phase of the detection value of the second magnetic sensor 121 are opposite in phase.
  • Examples of the first magnetic sensor 120 and the second magnetic sensor 121 include AMR (Anisotropic Magneto Resistance), GMR (Giant Magneto Resistance), TMR (Tunnel Magneto Resistance), BMR (Balistic Magneto Resistance), CMR (Colossal Magneto Resistance), and the like.
  • a magnetic sensor having a magnetoresistive element can be used.
  • a magnetic sensor using an AMR element having a barber pole structure having an odd function input / output characteristic and a Wheatstone bridge type bridge circuit or a half bridge circuit which is a half circuit configuration thereof can be used.
  • first magnetic sensor 120 and the second magnetic sensor 121 a magnetic sensor having a Hall element, a magnetic sensor having an MI (Magneto Impedance) element using a magnetic impedance effect, a fluxgate type magnetic sensor, or the like is used. Can do.
  • the method is not limited to the method using the barber pole structure, and an induction magnetic field generated around the coil, a magnetic field of a permanent magnet, or a magnetic field combining these is used. May be biased.
  • the first magnetic sensor 120 and the second magnetic sensor 121 an open-loop magnetic field measurement without an exciting coil portion may be performed.
  • the first magnetic sensor 120 and the second magnetic sensor 121 output via an amplifier and a converter that amplify while linearly amplifying or correcting the output of the element.
  • the first magnetic sensor 120 and the second magnetic sensor 121 may perform a closed loop magnetic field measurement having an exciting coil section.
  • each of the first magnetic sensor 120 and the second magnetic sensor 121 includes a sensor circuit in which a closed loop of an exciting coil is configured.
  • a drive current is supplied to the excitation coil unit from the excitation coil drive unit.
  • a magnetic field generated by the drive current flowing through the exciting coil is applied to the first magnetic sensor 120 and the second magnetic sensor 121.
  • a magnetic field generated by a current flowing through the primary conductor 110 is also applied to the first magnetic sensor 120 and the second magnetic sensor 121. Therefore, the first magnetic sensor 120 and the second magnetic sensor 121 are applied with the magnetic field generated from the exciting coil and the magnetic field generated by the current flowing through the primary conductor 110 overlapping each other.
  • the strength of the magnetic field applied so as to overlap the first magnetic sensor 120 and the second magnetic sensor 121 becomes a value obtained by superimposing them according to the so-called superposition principle.
  • the exciting coil driving unit supplies a driving current to the exciting coil unit so that the strength of the magnetic field applied to the first magnetic sensor 120 and the second magnetic sensor 121 is zero due to the negative feedback.
  • the measurement is performed in a state in which a magnetic field having a certain strength (approximately 0) is applied to the first magnetic sensor 120 and the second magnetic sensor 121.
  • a magnetic field having a certain strength approximately 0
  • the influence of the nonlinearity of the input / output characteristics (the relationship between the input magnetic field and the output voltage) of the sensor 120 and the second magnetic sensor 121 on the linearity of the measurement result can be reduced.
  • the first magnetic sensor 120 is electrically connected to the subtractor 130 by the first connection wiring 141.
  • the second magnetic sensor 121 is electrically connected to the subtractor 130 by the second connection wiring 142.
  • the subtractor 130 calculates the value of the current flowing through the primary conductor 110 by subtracting the detection value of the first magnetic sensor 120 and the detection value of the second magnetic sensor 121.
  • the subtractor 130 is used as the calculation unit.
  • the calculation unit is not limited to this, and a differential amplifier or the like may be used.
  • the magnetic body 160 has a box shape in which one surface covering the outer peripheral side of the cylindrical portion 111 and the side opposite to the cylindrical portion 111 side of the connecting portion 113 is opened.
  • the magnetic body 160 has an opening on the other opening side of the cylindrical portion 111.
  • the shape of the magnetic body 160 is not limited to the above, and may be any shape that at least surrounds the portion of the primary conductor 110 facing each of the first magnetic sensor 120 and the second magnetic sensor 121.
  • the magnetic body 160 is made of permalloy, but the material of the magnetic body 160 is not limited to permalloy, such as soft iron steel, silicon steel, electromagnetic steel, nickel alloy, iron alloy, or ferrite, Any material having a high magnetic permeability and high saturation magnetic flux density may be used.
  • a magnetic air gap 150 is formed between the magnetic body 160 and the primary conductor 110.
  • a material having a low magnetic permeability close to 1 is preferably disposed. Further, it is desirable that the material disposed in the magnetic gap 150 has high electrical insulation and heat resistance.
  • the material disposed in the magnetic gap 150 may be engineering plastics such as polyphenylene sulfide (PPS) resin, liquid crystal polymer (LCP), polybutylene terephthalate (PBT) resin or polyamide resin (PA), or epoxy resin or A thermosetting resin such as bakelite may be used.
  • PPS polyphenylene sulfide
  • LCP liquid crystal polymer
  • PBT polybutylene terephthalate
  • PA polyamide resin
  • a thermosetting resin such as bakelite
  • the material disposed in the magnetic gap 150 may be an inorganic material such as alumina, steatite, glass, or ceramics, or a composite material thereof.
  • the material disposed in the magnetic gap 150 may be air or a nonmagnetic metal. However, when the material disposed in the magnetic gap 150 is air, a structure for maintaining a gap between the magnetic body 160 and the primary conductor 110 is required. When the material disposed in the magnetic gap 150 is a nonmagnetic metal, an insulating structure between the nonmagnetic metal and the primary conductor 110 is required.
  • an epoxy resin is disposed in the magnetic gap 150.
  • the magnetic body 160 and the primary conductor 110 are bonded to each other by a layer made of an epoxy resin.
  • the primary conductor 110 may be insert-molded in the above resin material.
  • two recesses for accommodating each of the first magnetic sensor 120 and the second magnetic sensor 121 are provided in the resin portion between the cylindrical portion 111 and the second flat plate portion 112.
  • the strength of the magnetic field detected by the first magnetic sensor 120 is a positive value
  • the strength of the magnetic field detected by the second magnetic sensor 121 is a negative value.
  • the detection value of the first magnetic sensor 120 and the detection value of the second magnetic sensor 121 are transmitted to the subtractor 130.
  • the subtracter 130 subtracts the detection value of the second magnetic sensor 121 from the detection value of the first magnetic sensor 120. As a result, the absolute value of the detection value of the first magnetic sensor 120 and the absolute value of the detection value of the second magnetic sensor 121 are added. From this addition result, the value of the current flowing through the primary conductor 110 is calculated.
  • the external magnetic field source is physically the first magnetic sensor. It cannot be positioned between the sensor 120 and the second magnetic sensor 121.
  • the direction of the magnetic field component in the direction of the detection axis indicated by the arrow 120a and the magnetic field applied from the external magnetic field source to the second magnetic sensor 121 is the same direction. Therefore, when the strength of the external magnetic field detected by the first magnetic sensor 120 is a positive value, the strength of the external magnetic field detected by the second magnetic sensor 121 is also a positive value.
  • the subtractor 130 subtracts the detection value of the second magnetic sensor 121 from the detection value of the first magnetic sensor 120, thereby detecting the absolute value of the detection value of the first magnetic sensor 120 and the detection of the second magnetic sensor 121.
  • the absolute value of the value is subtracted. Thereby, the magnetic field from the external magnetic field source is hardly detected. That is, the influence of the external magnetic field is reduced.
  • the directions of the detection axes with positive detection values may be opposite to each other (180 ° opposite). In this case, if the strength of the external magnetic field detected by the first magnetic sensor 120 is a positive value, the strength of the external magnetic field detected by the second magnetic sensor 121 is a negative value.
  • the phase of the detection value of the first magnetic sensor 120 and the phase of the detection value of the second magnetic sensor 121 are in phase.
  • an adder or an addition amplifier is used as the calculation unit instead of the subtracter 130.
  • the detected value of the first magnetic sensor 120 and the detected value of the second magnetic sensor 121 are added by an adder or an adding amplifier, thereby obtaining the absolute value of the detected value of the first magnetic sensor 120.
  • the absolute value of the detection value of the second magnetic sensor 121 is subtracted. Thereby, the magnetic field from the external magnetic field source is hardly detected. That is, the influence of the external magnetic field is reduced.
  • the strength of the magnetic field generated by the current flowing through the primary conductor 110 is obtained by adding the detection value of the first magnetic sensor 120 and the detection value of the second magnetic sensor 121 by an adder or an addition amplifier.
  • the absolute value of the detection value of the first magnetic sensor 120 and the absolute value of the detection value of the second magnetic sensor 121 are added. From this addition result, the value of the current flowing through the primary conductor 110 is calculated.
  • an adder or an addition amplifier may be used as the calculation unit in place of the subtracter 130 while the input / output characteristics of the first magnetic sensor 120 and the second magnetic sensor 121 have opposite polarities.
  • the cylindrical portion 111 has a point-symmetric shape with respect to the center point 112c of the second flat plate portion 112 in the cross section.
  • the cylindrical portion 111 has a shape that is symmetrical with respect to the center line of the second flat plate portion 112 in the direction of the detection axis of the first magnetic sensor 120 and the second magnetic sensor 121 in the cross section.
  • first magnetic sensor 120 and the second magnetic sensor 121 are located point-symmetrically with respect to the center point 112c of the second flat plate portion 112 in the cross section.
  • the first magnetic sensor 120 and the second magnetic sensor 121 are symmetrical with respect to each other about the center line of the second flat plate portion 112 in the direction of the detection axis of the first magnetic sensor 120 and the second magnetic sensor 121 in the cross section. positioned.
  • the magnetic field 112e that circulates around the second flat plate portion 112 is equivalently applied to each of the first magnetic sensor 120 and the second magnetic sensor 121 in the opposite direction.
  • the detection value of the magnetic field 112e is doubled.
  • the external magnetic field source is sufficiently far from the first magnetic sensor 120 and the second magnetic sensor 121
  • the external magnetic field is equivalent to each of the first magnetic sensor 120 and the second magnetic sensor 121 in the same direction.
  • the detection value of the external magnetic field becomes zero by subtracting the detection value of the second magnetic sensor 121 from the detection value of the first magnetic sensor 120 by the subtractor 130.
  • the first magnetic sensor 120 and the second magnetic sensor 121 show detection values that equally reflect the magnetic field generated by the current flowing through the primary conductor 110. Therefore, the linearity between the strength of the magnetic field generated by the current flowing through the primary conductor 110 and the value of the current flowing through the primary conductor 110 calculated therefrom can be improved.
  • the current sensor 100 Since the current sensor 100 according to the present embodiment satisfies both the point-symmetrical arrangement and the line-symmetrical arrangement described above, the strength of the magnetic field generated by the current flowing through the primary conductor 110 regardless of the position of the external magnetic field source 10. And the influence of the external magnetic field can be reduced while improving the linearity between the current flowing through the primary conductor 110 and the value of the current flowing through the primary conductor 110.
  • the high frequency component of the external magnetic field can penetrate only to a depth of about 2 to 3 times the skin depth of the cylindrical portion 111 due to the skin effect. Therefore, it can suppress that the high frequency component of an external magnetic field reaches the 1st magnetic sensor 120 and the 2nd magnetic sensor 121 which are arrange
  • the thickness dimension T 1 of the cylindrical portion 111 is determined in accordance with the frequency of the high frequency component of the external magnetic field that is assumed.
  • the influence of the external magnetic field is reduced by subtracting the detection value of the second magnetic sensor 121 from the detection value of the first magnetic sensor 120 using a differential amplifier such as an operational amplifier, the external performance is limited due to the performance limitation of the differential amplifier. In some cases, the high frequency component of the magnetic field cannot be completely subtracted. As described above, by reducing the penetration of high-frequency components in the external magnetic field by the skin effect, the influence of the external magnetic field can be reduced regardless of the performance limit of the differential amplifier.
  • the current sensor according to the present embodiment will be described in comparison with the current sensor according to the first comparative example.
  • FIG. 5 is a plan view showing the shape of the primary conductor provided in the current sensor according to the first comparative example.
  • FIG. 6 is a contour map showing the result of simulating the magnetic flux density of the magnetic field generated around the primary conductor of the current sensor according to the first comparative example, as seen in the section taken along the line VI-VI in FIG. .
  • FIG. 7 shows the distance from the central portion of the first flat plate portion or the central portion of the second flat plate portion in the left-right direction in FIG. 6 to the vertical direction in FIG. 6 and the magnetic flux in the current sensor according to the first comparative example. It is a graph which shows the relationship with a density.
  • the vertical axis indicates the magnetic flux density (mT)
  • the horizontal axis indicates the distance (mm) from the surface of the primary conductor.
  • FIG. 8 is a magnetic flux diagram showing the result of simulating the magnetic flux density of the magnetic field generated around the primary conductor of the current sensor according to the present embodiment.
  • FIG. 9 is a contour diagram showing the result of simulating the magnetic flux density of the magnetic field generated around the primary conductor of the current sensor according to the present embodiment. 8 and 9 show the same cross section as FIG.
  • FIG. 10 is a graph showing the relationship between the distance from the central portion of the second flat plate portion in the left-right direction in FIG. 9 to the vertical direction in FIG. 9 and the magnetic flux density in the current sensor according to the present embodiment.
  • the vertical axis represents the magnetic flux density (mT)
  • the horizontal axis represents the distance (mm) from the surface of the second flat plate portion.
  • the current sensor according to the first comparative example includes a primary conductor 910 through which a current to be measured flows.
  • the primary conductor 910 includes a first flat plate portion 911 and a second flat plate portion 912 which are positioned in parallel with a space therebetween. One end of the first flat plate portion 911 and one end of the second flat plate portion 912 are connected by a connecting portion 913.
  • the primary conductor 910 is formed in a thin plate shape. The current flows from the first flat plate portion 911 to the second flat plate portion 912 through the connecting portion 913.
  • each flat plate portion in this embodiment and the first comparative example was 2 mm ⁇ 10 mm, and the value of the current flowing through the primary conductor was 100 A.
  • the line having a magnetic flux density of 0.6 mT is E 1
  • the line having 1.2 mT is E 2
  • the line having 1.8 mT is E 3
  • the line having 2.4 mT is E 4
  • a line that is 0.0 mT is E 5
  • a line that is 3.6 mT is E 6
  • a line that is 4.2 mT is E 7
  • a line that is 4.8 mT is E 8
  • a line that is 5.4 mT is E 9
  • 6 A line that is 0.0 mT is indicated by E 10 .
  • a line having a magnetic flux density of 0.3 mT is E 11
  • a line having a 0.6 mT is E 12
  • a line having a 0.9 mT is E 13
  • a line having a 1.2 mT is E 14
  • 1 A line of .5 mT is represented by E 15
  • a line of 1.8 mT is represented by E 16
  • a line of 2.1 mT is represented by E 17
  • a line of 2.4 mT is represented by E 18 .
  • the magnetic flux density increases as the distance from the central portion of the first flat plate portion 911 or the central portion of the second flat plate portion 912 increases in the vertical direction in FIG. It has dropped rapidly.
  • the width dimension H of the second flat plate portion 112 is 1.5 times or more the maximum value of the distance dimensions G 1 and G 2 between the adjacent flat plate portions. .
  • the magnetic flux lines of the magnetic field generated between the cylindrical portion 111 and the second flat plate portion 112 are substantially linear along the second flat plate portion 112 in the left-right direction in the drawing. It extends.
  • the horizontal direction in the figure is the direction of the detection axis of the first and second magnetic sensors 120 and 121.
  • the first magnetic sensor 120 and the second magnetic sensor 121 are arranged closer to the second flat plate portion 112 than the cylindrical portion 111, so that the magnetic flux density is almost changed.
  • the first magnetic sensor 120 and the second magnetic sensor 121 can be positioned in the non-existing region, and the first magnetic sensor 120 and the second magnetic sensor 121 have a high frequency of an external magnetic field due to the skin effect of the cylindrical portion 111 as described above. It can suppress that an ingredient reaches.
  • the current sensor 100 can be easily manufactured. This effect is stably obtained when the width dimension H of the second flat plate portion 112 is 1.5 G 1 or more, and becomes prominent when it is 2.0 G 1 or more.
  • the length Le in the extending direction of the second flat plate portion 112 is equal to or larger than the width H of the second flat plate portion 112.
  • the 1st magnetic sensor 120 and the 2nd magnetic sensor 121 can be arranged apart from connection part 113 more than predetermined distance.
  • high accuracy is not required for the arrangement of the first magnetic sensor 120 and the second magnetic sensor 121 in the extending direction of the second flat plate portion 112. Therefore, the current sensor 100 can be easily manufactured.
  • the primary conductor 110 according to the present embodiment has a region where the magnetic flux density is lower than 0.6 mT in the primary conductor 110 compared to the primary conductor 910 of the first comparative example. Is formed near. That is, the leakage magnetic field of the primary conductor 110 according to the present embodiment is smaller than the leakage magnetic field of the primary conductor 910 of the first comparative example.
  • each of the first magnetic sensor 120 and the second magnetic sensor 121 is surrounded by the cylindrical portion 111, the magnetic gap 150, and the magnetic body 160. It is possible to suppress the external magnetic field that is an error factor from reaching each of 120 and the second magnetic sensor 121. As a result, each of the first magnetic sensor 120 and the second magnetic sensor 121 can be prevented from detecting an unnecessary external magnetic field.
  • the primary conductor 110 is surrounded by the magnetic gap 150, the magnetic flux entering the magnetic body 160 is reduced by the magnetic field generated by the current flowing through the primary conductor 110. As a result, magnetic saturation of the magnetic body 160 due to the magnetic field generated by the current flowing through the primary conductor 110 can be suppressed. Therefore, even when the magnetic body 160 is thinned, the external magnetic field can be shielded.
  • the magnetic flux generated by the magnetic field generated by the current flowing through the primary conductor 110 is reduced, so that the influence of the eddy current generated in the magnetic body 160 is affected by the first magnetic sensor 120 and the second magnetic sensor 121. Since it can be suppressed from reaching each, a current sensor with good responsiveness and frequency characteristics can be realized.
  • FIG. 11 is a perspective view showing a configuration of a current sensor according to Embodiment 2 of the present invention.
  • FIG. 12 is a cross-sectional view of the current sensor of FIG. 11 as viewed from the direction of arrows XII-XII.
  • a current sensor 200 according to Embodiment 2 of the present invention includes a primary conductor 210 through which a current to be measured flows.
  • the current sensor 200 includes a first magnetic sensor 220 and a second magnetic sensor 221 that detect the strength of a magnetic field generated by the current to be measured flowing through the primary conductor 210 with an odd function input / output characteristic. .
  • the current sensor 200 includes a subtracter 230 that is a calculation unit that calculates the current value by subtracting the detection values of the first magnetic sensor 220 and the second magnetic sensor 221.
  • the primary conductor 210 includes a first flat plate portion 211, a second flat plate portion 212, and a third flat plate portion 213 that are electrically connected in series.
  • the first flat plate portion 211 and the third flat plate portion 213 extend in parallel with an interval between each other, and are connected to each other by the second flat plate portion 212.
  • the second flat plate portion 212 extends in parallel with the first flat plate portion 211 and the third flat plate portion 213 at intervals.
  • the primary conductor 210 includes a first connecting portion 214 that connects the other end in the longitudinal direction of the first flat plate portion 211 and one end in the longitudinal direction of the second flat plate portion 212, and the second flat plate portion 212.
  • a second connecting portion 215 that connects the other end in the longitudinal direction of the third flat plate portion 213 and one end in the longitudinal direction of the third flat plate portion 213.
  • the 1st flat plate part 211, the 2nd flat plate part 212, and the 3rd flat plate part 213 are arrange
  • the first connecting portion 214 extends linearly in a side view and is orthogonal to each of the first flat plate portion 211 and the second flat plate portion 212.
  • the second connecting portion 215 extends linearly in a side view and is orthogonal to each of the second flat plate portion 212 and the third flat plate portion 213.
  • the first magnetic sensor 220 is located between the first flat plate portion 211 and the second flat plate portion 212 facing each other.
  • the second magnetic sensor 221 is located between the second flat plate portion 212 and the third flat plate portion 213 facing each other.
  • the first magnetic sensor 220 has a direction orthogonal to the direction in which the first flat plate portion 211, the second flat plate portion 212, and the third flat plate portion 213 are aligned, and the extension of the second flat plate portion 212.
  • the detection axis is in the direction indicated by the arrow 220a in FIG. 11, which is a direction orthogonal to the current direction.
  • the second magnetic sensor 221 is orthogonal to the direction in which the first flat plate portion 211, the second flat plate portion 212, and the third flat plate portion 213 are aligned, and is orthogonal to the extending direction of the second flat plate portion 212.
  • the detection axis is in the direction indicated by the arrow 221a in FIG.
  • the first magnetic sensor 220 and the second magnetic sensor 221 output a positive value when a magnetic field directed in one direction of the detection axis is detected, and a magnetic field directed in a direction opposite to the one direction of the detection axis. It has an odd function input / output characteristic that outputs a negative value when detected.
  • the first magnetic sensor 220 is electrically connected to the subtracter 230 by the first connection wiring 241.
  • the second magnetic sensor 221 is electrically connected to the subtracter 230 by the second connection wiring 242.
  • the subtracter 230 calculates the value of the current to be measured flowing through the primary conductor 210 by subtracting the detection value of the second magnetic sensor 221 from the detection value of the first magnetic sensor 220.
  • Dimension H of each width of the first flat plate portion 211, the second flat plate portion 212, and the third flat plate portion 213 in the direction of the detection axis of the first and second magnetic sensors 220, 221 indicated by arrows 220a, 221a in FIG. Is 1.5 times the distance dimensions G 1 and G 2 between the adjacent flat plate portions.
  • the dimension H of the width of the first flat plate portion 211, the size of the width of the second flat plate portion 212 H, and the dimension H in the width of the third flat plate portion 213 are each 1.5G 1.
  • the width dimension H of the first flat plate portion 211, the width dimension H of the second flat plate portion 212, and the width dimension H of the third flat plate portion 213 are each 1.5 G 1 or more. It is more preferable that each is 2.0 G 1 or more.
  • variety of the 1st flat plate part 211, the 2nd flat plate part 212, and the 3rd flat plate part 213 may mutually differ.
  • the primary conductor 210 is formed by bending one plate-like conductive member.
  • the direction 21 in which the current flows through the first flat plate portion 211 and the direction 25 in which the current flows through the third flat plate portion 213 are the same.
  • the direction 21 in which the current flows through the first flat plate portion 211, the direction 25 in which the current flows through the third flat plate portion 213, and the direction 23 in which the current flows through the second flat plate portion 212 are opposite.
  • the direction 22 in which the current flows through the first connecting portion 214 and the direction 24 in which the current flows through the second connecting portion 215 are the same.
  • the primary conductor 210 is connected to external wiring including input wiring and output wiring. Therefore, the current input to the first flat plate portion 211 flows through the first connecting portion 214, the second flat plate portion 212, and the second connecting portion 215 in this order, and is output from the third flat plate portion 213.
  • FIG. 13 is a diagram schematically showing a generated magnetic field in a cross-sectional view of the current sensor according to the present embodiment as viewed from the direction of arrows XIII-XIII in FIG.
  • the detection axis direction of the first magnetic sensor 220 and the second magnetic sensor 221 is indicated as the X direction
  • the direction in which the first flat plate portion 211, the second flat plate portion 212, and the third flat plate portion 213 are aligned is indicated as the Y direction.
  • the extending direction of the 2nd flat plate part 212 is a Z direction.
  • a leftward magnetic field in the figure is applied to the first magnetic sensor 220 in the direction of the detection axis indicated by the arrow 220a.
  • the right magnetic field in the figure is applied to the second magnetic sensor 221 in the direction of the detection axis indicated by the arrow 221a.
  • the detection value indicating the strength of the magnetic field detected by the first magnetic sensor 220 is a positive value
  • the detection value indicating the strength of the magnetic field detected by the second magnetic sensor 221 is a negative value.
  • the detection value of the first magnetic sensor 220 and the detection value of the second magnetic sensor 221 are transmitted to the subtracter 230.
  • the subtracter 230 subtracts the detection value of the second magnetic sensor 221 from the detection value of the first magnetic sensor 220. As a result, the absolute value of the detection value of the first magnetic sensor 220 and the absolute value of the detection value of the second magnetic sensor 221 are added. From this addition result, the value of the current to be measured flowing through the primary conductor 210 is calculated.
  • the magnetic body 260 has a cylindrical shape with both ends opened. One end of the first flat plate portion 211 in the longitudinal direction protrudes from an opening on one end side of the magnetic body 260. The other end of the third flat plate portion 213 in the longitudinal direction protrudes from the opening on the other end side of the magnetic body 260.
  • the shape of the magnetic body 260 is not limited to the above, and may be any shape that at least surrounds the portion of the primary conductor 210 that faces each of the first magnetic sensor 220 and the second magnetic sensor 221.
  • the magnetic body 260 is made of permalloy, but the material of the magnetic body 260 is not limited to permalloy, such as soft iron steel, silicon steel, electromagnetic steel, nickel alloy, iron alloy, or ferrite, Any material having a high magnetic permeability and high saturation magnetic flux density may be used.
  • a magnetic gap 250 is formed between the magnetic body 260 and the primary conductor 210. It is preferable that a material having a low magnetic permeability close to 1 is disposed in the magnetic gap 250. Further, it is desirable that the material disposed in the magnetic gap 250 has high electrical insulation and heat resistance.
  • the material disposed in the magnetic gap 250 may be engineering plastics such as polyphenylene sulfide (PPS) resin, liquid crystal polymer (LCP), polybutylene terephthalate (PBT) resin or polyamide resin (PA), or epoxy resin or A thermosetting resin such as bakelite may be used.
  • PPS polyphenylene sulfide
  • LCP liquid crystal polymer
  • PBT polybutylene terephthalate
  • PA polyamide resin
  • a thermosetting resin such as bakelite
  • the material disposed in the magnetic gap 150 may be an inorganic material such as alumina, steatite, glass, or ceramics, or a composite material thereof.
  • the material disposed in the magnetic gap 250 may be air or a nonmagnetic metal.
  • the material disposed in the magnetic gap 250 is air, a structure for maintaining a gap between the magnetic body 260 and the primary conductor 210 is required.
  • the material disposed in the magnetic gap 250 is a nonmagnetic metal, an insulating structure between the nonmagnetic metal and the primary conductor 210 is required.
  • an epoxy resin is disposed in the magnetic gap 250.
  • the magnetic body 260 and the primary conductor 210 are bonded to each other by a layer made of an epoxy resin.
  • the primary conductor 210 may be insert-molded in the above resin material.
  • two recesses for accommodating each of the first magnetic sensor 220 and the second magnetic sensor 221 are provided between the first flat plate portion 111a and the second flat plate portion 112, and between the second flat plate portion 112 and the second flat plate portion 112. It is provided in each resin part between the three flat plate parts 111b.
  • FIG. 14 is a magnetic flux diagram showing the result of simulating the magnetic flux density of the magnetic field generated by the current to be measured flowing through the primary conductor around the primary conductor of the current sensor according to the present embodiment.
  • FIG. 15 is a contour map showing the result of simulating the magnetic flux density of the magnetic field generated by the current to be measured flowing through the primary conductor around the primary conductor of the current sensor according to the present embodiment. 14 and 15 show the same cross section as FIG.
  • FIG. 16 is a graph showing the relationship between the distance from the central portion of the second flat plate portion 212 in the left-right direction in FIG. 13 to the vertical direction in FIG. 13 and the magnetic flux density in the current sensor according to the present embodiment. is there.
  • the vertical axis indicates the magnetic flux density (mT)
  • the horizontal axis indicates the distance (mm) from the surface of the second flat plate portion.
  • each flat plate portion in this embodiment is 2 mm ⁇ 10 mm, and the value of the current to be measured flowing through the primary conductor is 100 A.
  • the line having a magnetic flux density of 0.7 mT is E 21
  • the line having 1.4 mT is E 22
  • the line having 2.1 mT is E 23
  • the line having 2.8 mT is E 24
  • the line is .5mT E 25
  • E 26 a line is 4.2mT
  • E 27 a line is 4.9MT
  • a line is 5.6mT E 28, show a line is 6.3mT in E 29 ing.
  • the dimension H of each width of the first flat plate portion 211, the second flat plate portion 212, and the third flat plate portion 213 is the distance dimension G 1 between the adjacent flat plate portions. it is 1.5 times of the G 2.
  • the magnetic flux lines of the magnetic field to be extended substantially linearly along each flat plate portion in the left-right direction in the figure.
  • the horizontal direction in the figure is the direction of the detection axis of the first and second magnetic sensors 220 and 221.
  • the magnetic flux density is 6.3 mT in the vicinity of the first flat plate portion 211 between the first flat plate portion 211 and the second flat plate portion 212. A higher region is formed.
  • the magnetic flux density is about 6.1 mT and hardly changes at the second flat plate portion 212 side in the central portion in the horizontal direction in the drawing. Is formed.
  • a region having a magnetic flux density higher than 6.3 mT is formed in the vicinity of the third flat plate portion 213 between the second flat plate portion 212 and the third flat plate portion 213.
  • the magnetic flux density is about 6.1 mT and hardly changes in the central portion in the left-right direction in the drawing on the second flat plate portion 212 side. Is formed.
  • the first magnetic sensor 220 is disposed closer to the first flat plate portion 211 than the second flat plate portion 212, and the second magnetic sensor 221 is disposed from the second flat plate portion 212 to the third flat plate. Since the first magnetic sensor 220 and the second magnetic sensor 221 can be disposed in a region having a high magnetic flux density by being disposed near the portion 213, the SN ratio (signal-noise ratio) of the current sensor 200 can be increased. . In this case, the sensitivity of the current sensor 200 can be improved.
  • the first magnetic sensor 220 is disposed closer to the second flat plate portion 212 than the first flat plate portion 211, and the second magnetic sensor 221 is connected to the second flat plate from the third flat plate portion 213. Since the first magnetic sensor 220 and the second magnetic sensor 221 can be arranged in a region where the magnetic flux density hardly changes by being arranged near the portion 212, the arrangement of the first magnetic sensor 220 and the second magnetic sensor 221 can be reduced. High accuracy is not required. In this case, the current sensor 200 can be easily manufactured. This effect is stably obtained when the width H of each of the first flat plate portion 211, the second flat plate portion 212, and the third flat plate portion 213 is 1.5 G 1 or more, and is 2.0 G 1 or more. It becomes noticeable in some cases.
  • the length L 10 in the extending direction of the second flat plate portion 212 is equal to or larger than the width H of the second flat plate portion 212.
  • the 1st magnetic sensor 220 can be arranged apart from the 1st connection part 214 more than predetermined distance.
  • the second magnetic sensor 221 can be arranged at a predetermined distance or more away from the second connecting portion 215. As a result, high accuracy is not required for the arrangement of the first magnetic sensor 220 and the second magnetic sensor 221 in the extending direction of the second flat plate portion 212. Therefore, the current sensor 200 can be easily manufactured.
  • the influence of the external magnetic field can be reduced. Moreover, since the high precision is not requested
  • the primary conductor 210 according to the present embodiment has a region where the magnetic flux density is lower than 0.6 mT near the primary conductor as compared with the primary conductor 910 of the comparative example. Is formed. That is, the leakage magnetic field of the primary conductor 210 according to the present embodiment is smaller than the leakage magnetic field of the primary conductor 910 of the comparative example.
  • the current flowing through each path is obtained by using the current sensor 200 according to the present embodiment. Can be detected more accurately.
  • each of the first magnetic sensor 220 and the second magnetic sensor 221 is surrounded by the primary conductor 210, the magnetic gap 250, and the magnetic body 260. It is possible to suppress the external magnetic field that is an error factor from reaching each of 220 and the second magnetic sensor 221. As a result, each of the first magnetic sensor 220 and the second magnetic sensor 221 can be prevented from detecting an unnecessary external magnetic field.
  • the primary conductor 210 is surrounded by the magnetic gap 250, the magnetic flux entering the magnetic body 260 is reduced by the magnetic field generated by the current flowing through the primary conductor 210. As a result, magnetic saturation of the magnetic body 260 due to the magnetic field generated by the current flowing through the primary conductor 210 can be suppressed. Therefore, even when the magnetic body 260 is thinned, the external magnetic field can be shielded.
  • the influence of the residual magnetic flux density of the magnetic body 260 affects each of the first magnetic sensor 220 and the second magnetic sensor 221. Therefore, a current sensor with small hysteresis can be realized.
  • the magnetic flux generated by the magnetic field generated by the current flowing through the primary conductor 210 is reduced, so that the influence of the eddy current generated in the magnetic body 260 is affected by the first magnetic sensor 220 and the second magnetic sensor 221. Since it can be suppressed from reaching each, a current sensor with good responsiveness and frequency characteristics can be realized.
  • 10 external magnetic field source 100, 200 current sensor, 110, 210, 910 primary conductor, 111 cylindrical part, 111a, 211, 911 first flat plate part, 111b, 213 third flat plate part, 111c, 111d side wall part, 111s 1st female thread, 112, 212, 912 2nd flat plate part, 112c center point, 112e, 211e, 212e, 213e magnetic field, 112s 2nd female thread, 113 connection part, 120, 220 1st magnetic sensor, 121, 221 2nd magnetism Sensor, 130, 230 subtractor, 141, 241 first connection wiring, 142, 242 second connection wiring, 150, 250 magnetic gap, 160, 260 magnetic body, 170 input wiring, 171 output wiring, 172 connection conductor, 173 1st through hole, 174, 2nd through hole, 180 nut, 1 0 volt, 214 first connecting portion 215 second connecting portion, 913 connection.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)

Abstract

L'invention concerne un capteur de courant qui comporte un conducteur primaire (110) à travers lequel le courant à mesurer circule, un premier capteur magnétique (120) permettant de détecter l'intensité du champ magnétique généré par le courant circulant dans le conducteur primaire (110), et un corps magnétique (160) entourant le conducteur primaire (110), un espace étant prévu entre ceux-ci. Le conducteur primaire (110) comprend une première partie de plaque plate (111a) et une seconde partie de plaque plate (112) disposées de manière à être opposées l'une à l'autre, un espace étant prévu entre celles-ci. La première partie de plaque plate (111a) et la seconde partie de plaque plate (112) sont électriquement connectées l'une à l'autre en série, et le courant passe par les parties de plaque plate dans des directions opposées. Le premier capteur magnétique (120) est disposé à l'intérieur de la zone entourée par le corps magnétique (160). Le premier capteur magnétique (120) est disposé entre la première partie de plaque plate (111a) et la seconde partie de plaque plate (112) de manière à être capable de détecter un champ magnétique orthogonal à la direction dans laquelle la première partie de plaque plate (111a) et la seconde partie de plaque plate (112) sont alignées.
PCT/JP2015/068327 2014-07-17 2015-06-25 Capteur de courant WO2016009807A1 (fr)

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Cited By (1)

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WO2022030177A1 (fr) * 2020-08-06 2022-02-10 株式会社村田製作所 Capteur de courant électrique

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JP2007183221A (ja) * 2006-01-10 2007-07-19 Denso Corp 電流センサ
JP2010008050A (ja) * 2008-06-24 2010-01-14 Tdk Corp 電流センサ

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DE102008061006A1 (de) * 2008-11-28 2010-06-02 Esw Gmbh Verfahren und Vorrichtung zur Messung von elektrischen Strom

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JP2007183221A (ja) * 2006-01-10 2007-07-19 Denso Corp 電流センサ
JP2010008050A (ja) * 2008-06-24 2010-01-14 Tdk Corp 電流センサ

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022030177A1 (fr) * 2020-08-06 2022-02-10 株式会社村田製作所 Capteur de courant électrique

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