WO2016035606A1 - Current sensor - Google Patents

Current sensor Download PDF

Info

Publication number
WO2016035606A1
WO2016035606A1 PCT/JP2015/073807 JP2015073807W WO2016035606A1 WO 2016035606 A1 WO2016035606 A1 WO 2016035606A1 JP 2015073807 W JP2015073807 W JP 2015073807W WO 2016035606 A1 WO2016035606 A1 WO 2016035606A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic
sensor
primary conductor
current
magnetic sensor
Prior art date
Application number
PCT/JP2015/073807
Other languages
French (fr)
Japanese (ja)
Inventor
清水　康弘
仁志 坂口
川浪　崇
Original Assignee
株式会社村田製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Publication of WO2016035606A1 publication Critical patent/WO2016035606A1/en

Links

Images

Classifications

    • 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.
  • JP 2010-2277 A Patent Document 1
  • JP 2010-8050 A Patent Document 2
  • JP 2013-11469 A Patent Document 3
  • JP 2013-238580 A Patent Document 4
  • JP 2013-228315 A Patent Document 5
  • JP 2001-281270 A Patent Document 6
  • the current sensor described in Patent Document 1 includes a bus bar, an insulating substrate, a Hall IC as a magnetic detection element, and a magnetic shield for each of the U phase, the V phase, and the W phase.
  • the upper magnetic shield member and the lower magnetic shield member form an annular enclosure that annularly surrounds the bus bar, the insulating substrate, and the Hall IC, thereby magnetically shielding the external magnetic field.
  • a gap is formed between the upper magnetic shield member and the lower magnetic shield member. The position in the height direction of the gap is the same as or near the position in the height direction of the bus bar, and the gap is located at a portion facing the side surface of the bus bar.
  • the Hall IC is arranged above the central portion of the bus bar.
  • the current sensor described in Patent Document 2 includes a nonmagnetic spacer in addition to the configuration of the current sensor described in Patent Document 1.
  • the protrusions of the nonmagnetic spacer are engaged with the gaps of the magnetic shield body. Thereby, the space
  • the current sensor described in Patent Document 3 includes a sensor substrate on which a magnetoresistive effect element is formed, a measured conductor through which a measured current flows, and a magnetic shield portion that surrounds the sensor substrate and the measured conductor. And have. Two gaps for suppressing magnetic saturation in the magnetic shield part are formed in the magnetic shield part, and the magnetic flux flowing in the magnetic shield part is released in the gap. An air gap is formed at a portion of the magnetic shield portion having a symmetrical structure. The height position of the air gap and the height position of the sensor substrate in the z direction are the same.
  • the current sensor described in Patent Document 4 includes a bus bar that is a conductor through which a current to be measured flows, a Hall IC as a magnetosensitive element, and first and second magnets that form a pair that magnetically shields the Hall IC from an external magnetic field. Have a body. Both ends of the first and second magnetic bodies forming a pair are opposed to each other with a gap.
  • the current sensor described in Patent Document 5 includes a bus bar, a main core, a sub core, and a magnetosensitive element.
  • the main core has an annular shape (C-type) with a gap, and the bus bar passes therethrough.
  • the sub-core is U-shaped (semi-annular) and its end face is located in the vicinity of the gap of the main core, is in non-contact with the main core and is in the same plane as the main core, and a part of the leakage flux of the main core flows.
  • the magnetosensitive element is a Hall element, and exists in a position where the magnetic field generated by the residual magnetization of the main core and the magnetic field generated by the residual magnetization of the sub core are weakened in the gap of the main core.
  • the current sensor described in Patent Document 6 includes a current sensor body, an inner magnetic shield case, and an outer magnetic shield case.
  • the dividing direction of the inner magnetic shield case and the dividing direction of the outer magnetic shield case intersect each other.
  • the inner magnetic shield case surrounds the current sensor body, and the outer magnetic shield case surrounds the inner magnetic shield case.
  • the influence of the magnetic field generated by the residual magnetization of the magnetic shield body is smaller than that of the current sensors described in Patent Documents 1 and 2, but the main core, the sub-core, and the magnetosensitive element. Are required to be arranged at appropriate positions, high assembly accuracy is required, and the manufacture of the current sensor is difficult.
  • the present invention has been made in view of the above problems, and an object of the present invention is to provide a current sensor that can be easily manufactured while reducing a measurement error due to a magnetic field generated by residual magnetization.
  • a current sensor includes a primary conductor through which a current to be measured flows, at least one magnetic sensor for detecting the strength of a magnetic field generated by the current flowing through the primary conductor, and a direction in which the current flows. And a pair of magnetic members each having an L shape.
  • the pair of magnetic members has a rectangular shape in which a gap is provided between the ends when viewed from the direction in which the current flows, and surrounds the primary conductor and the magnetic sensor.
  • the primary conductor has a flat plate shape.
  • the magnetic sensor can detect a magnetic field in a direction orthogonal to both the thickness direction of the primary conductor and the direction in which the current flows.
  • the magnetic sensor is disposed at least one of the one side and the other side in the thickness direction of the primary conductor in the central portion in the width direction of the primary conductor.
  • the current sensor includes a first magnetic sensor and a second magnetic sensor as magnetic sensors.
  • the first magnetic sensor and the second magnetic sensor are positioned to face each other with the primary conductor interposed therebetween.
  • 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 current sensor further includes another pair of magnetic members each having an L shape when viewed from the direction in which the current flows.
  • the other pair of magnetic members has a rectangular shape with a gap provided between the ends when viewed from the direction in which the current flows, and is spaced from the pair of magnetic members. Surrounding a pair of magnetic members. The gaps of the other pair of magnetic members are located outside the corners of each pair of magnetic members.
  • 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 disassembled perspective view which shows the structure of the current sensor which concerns on Embodiment 1 of this invention. It is a perspective view which shows the external appearance of the circuit board of the current sensor which concerns on Embodiment 1 of this invention. It is a circuit diagram which shows the circuit structure of the current sensor which concerns on Embodiment 1 of this invention.
  • FIG. 6 is a cross-sectional view showing a cross-sectional shape of a primary conductor according to Comparative Example 1.
  • FIG. 3 is a cross-sectional view showing a cross-sectional shape of a primary conductor according to Example 1.
  • FIG. 3 is a cross-sectional view schematically showing a magnetic field generated around a primary conductor according to Example 1.
  • FIG. The distance from the front surface or the back surface of the primary conductor and the width direction of the primary conductor (X-axis direction) on the reference line located immediately above or directly below the central portion in the width direction of the primary conductor according to Comparative Example 1 and Example 1 ) Is a graph showing the relationship with the magnetic flux density.
  • FIG. 17 is a cross-sectional view of the current sensor of FIG.
  • the distance from the center position in the thickness direction of the primary conductor on the reference line located immediately above or directly below the center portion in the width direction of the primary conductor 5 is a graph showing the relationship between the magnetic flux density in the length direction (Y-axis direction) of the primary conductor.
  • the distance from the center position in the thickness direction of the primary conductor on the reference line located immediately above or directly below the center portion in the width direction of the primary conductor 5 is a graph showing the relationship between the magnetic flux density in the thickness direction (Z-axis direction) of the primary conductor.
  • FIG. 10 is a graph showing hysteresis rates of a current sensor 100 according to Example 2, a current sensor 200 according to Comparative Example 2, a current sensor 300 according to Comparative Example 3, and a current sensor according to Comparative Example 4. It is sectional drawing which shows the structure of the current sensor which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the structure of the current sensor which concerns on Embodiment 3 of this invention.
  • the current sensor according to Embodiment 4 of the present invention it is a cross-sectional view showing a state where a printed board and a magnetic member are attached to a primary conductor.
  • the current sensor according to Embodiment 4 of the present invention it is a cross-sectional view showing a state before the printed board and the magnetic member are attached to the primary conductor.
  • FIG. 1 is a perspective view showing an appearance of a current sensor according to Embodiment 1 of the present invention.
  • FIG. 2 is a side view of the current sensor of FIG. 1 viewed from the direction of arrow II.
  • FIG. 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 an exploded perspective view showing the configuration of the current sensor according to Embodiment 1 of the present invention.
  • FIG. 5 is a perspective view showing an appearance of a circuit board of the current sensor according to the first embodiment of the present invention.
  • FIG. 6 is a circuit diagram showing a circuit configuration of the current sensor according to Embodiment 1 of the present invention.
  • the width direction of a primary conductor 110 which will be described later, is illustrated as an X-axis direction
  • the length direction of the primary conductor 110 is defined as a Y-axis direction
  • the thickness direction of the primary conductor 110 is illustrated as a Z-axis direction.
  • the current sensor 100 detects the primary conductor 110 through which the current to be measured flows and the strength of the magnetic field generated by the current through the primary conductor 110.
  • Two magnetic sensors are composed of a first magnetic sensor 120a and a second magnetic sensor 120b.
  • the current sensor 100 includes two magnetic sensors.
  • the present invention is not limited to this, and it is only necessary to include at least one magnetic sensor.
  • the current sensor 100 includes a pair of magnetic members 170 each having an L shape when the primary conductor 110 is viewed from the direction in which current flows (Y-axis direction).
  • the pair of magnetic members 170 includes a first magnetic member 171 and a second magnetic member 172.
  • the pair of magnetic members 170 has a rectangular shape in which a gap 173 is provided between ends of each other when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction).
  • the pair of magnetic members 170 includes a first circuit board 160a, a second circuit board 160b, and a portion sandwiched between the first circuit board 160a and the second circuit board 160b, which will be described later. It surrounds the second conductor 110 with a space.
  • the relative positions of the primary conductor 110, the first circuit board 160a, the second circuit board 160b, and the pair of magnetic members 170 are maintained by a case (not shown).
  • the case is preferably formed of an engineering plastic having high temperature resistance such as polyphenylene sulfide.
  • each of the first circuit board 160a and the second circuit board 160b and the case are fastened with screws, it is preferably fastened with screws made of a non-magnetic material so as not to disturb the magnetic field.
  • the primary conductor 110 has a flat plate shape.
  • the primary conductor 110 has one penetrating portion that penetrates from the front surface to the back surface of the primary conductor 110.
  • a circular through hole 110h is provided in a central portion in the width direction of the primary conductor 110 in a plan view. The current flows through the primary conductor 110 in the Y-axis direction.
  • the primary conductor 110 is made of copper.
  • the material of the primary conductor 110 is not limited to this, and may be a metal such as silver or aluminum or an alloy containing these metals.
  • the primary conductor 110 may be subjected to a surface treatment.
  • 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 formed by pressing a thin plate.
  • 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 cutting or casting.
  • the first magnetic sensor 120a is mounted on the first printed circuit board 130a together with the first operational amplifier 140a and the first passive element 150a.
  • the first magnetic sensor 120a is disposed at the center of the first printed circuit board 130a.
  • the first magnetic sensor 120a, the first printed board 130a, the first operational amplifier 140a, and the first passive element 150a constitute a first circuit board 160a.
  • the first printed circuit board 130a includes a substrate made of glass epoxy or alumina, and wiring formed by patterning a metal foil such as a copper foil on the substrate.
  • the first circuit board 160a is configured with an arithmetic circuit that calculates a signal from the first magnetic sensor 120a.
  • the second magnetic sensor 120b is mounted on the second printed circuit board 130b together with the second operational amplifier 140b and the second passive element 150b.
  • the second magnetic sensor 120b is disposed at the center of the second printed circuit board 130b.
  • the second magnetic sensor 120b, the second printed board 130b, the second operational amplifier 140b, and the second passive element 150b constitute a second circuit board 160b.
  • Second printed circuit board 130b includes a substrate made of glass epoxy or alumina, and a wiring formed by patterning a metal foil such as a copper foil on the substrate.
  • the second circuit board 160b is configured with an arithmetic circuit that calculates a signal from the second magnetic sensor 120b.
  • the first circuit board 160a is placed on the surface of the primary conductor 110.
  • the first magnetic sensor 120a is located immediately above the through hole 110h with the first printed board 130a sandwiched between the primary conductor 110.
  • the second circuit board 160 b is disposed on the back surface of the primary conductor 110.
  • the second magnetic sensor 120b is located directly below the through hole 110h with the second printed board 130b sandwiched between the primary conductor 110.
  • first magnetic sensor 120a and the second magnetic sensor 120b are located on opposite sides of the primary conductor 110.
  • the first magnetic sensor 120 a is disposed on one side (upper side) in the thickness direction (Z-axis direction) of the primary conductor 110 in the central portion in the width direction (X-axis direction) of the primary conductor 110.
  • the second magnetic sensor 120b is disposed on the other side (lower side) in the thickness direction (Z-axis direction) of the primary conductor 110 at the center in the width direction (X-axis direction) of the primary conductor 110.
  • the direction (magnetic direction) of the detection axis of each of the first magnetic sensor 120a and the second magnetic sensor 120b is the width direction (X-axis direction) of the primary conductor 110. That is, each of the first magnetic sensor 120a and the second magnetic sensor 120b is orthogonal to both the thickness direction (Z-axis direction) of the primary conductor 110 and the direction in which the current flows through the primary conductor 110 (Y-axis direction).
  • the magnetic field in the direction (X-axis direction) can be detected.
  • Each of the first magnetic sensor 120a and the second magnetic sensor 120b outputs a positive value when a magnetic field directed in one direction of the detection axis is detected, and is directed in a direction opposite to the one direction of the detection axis. It has an input / output characteristic that outputs a negative value when a magnetic field is detected.
  • Each of the first magnetic sensor 120a and the second magnetic sensor 120b has a Wheatstone bridge type bridge circuit including four AMR (Anisotropic Magneto Resistance) elements.
  • Each of the first magnetic sensor 120a and the second magnetic sensor 120b is replaced with an AMR element, and GMR (Giant Magneto Resistance), TMR (Tunnel Magneto Resistance), BMR (Balistic Magneto Resistance), CMR (Colossal Magneto Resistance). It may have a magnetoresistive element.
  • each of the first magnetic sensor 120a and the second magnetic sensor 120b may have a half bridge circuit including two magnetoresistive elements.
  • 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.
  • Magnetic elements such as a magnetoresistive element and a Hall element may be packaged with a resin, or may be potted with a silicone resin or an epoxy resin.
  • Each AMR element of the first magnetic sensor 120a and the second magnetic sensor 120b has an odd function input / output characteristic by including a barber pole type electrode.
  • each AMR element of the first magnetic sensor 120a and the second magnetic sensor 120b includes a barber pole type electrode, and is biased so that a current flows at a predetermined angle.
  • the magnetization direction of the magnetoresistive film in the AMR element of the first magnetic sensor 120a and the magnetization direction of the magnetoresistive film in the AMR element of the second magnetic sensor 120b are the same direction. Thereby, the fall of the output accuracy by the influence of an external magnetic field can be made small.
  • the current sensor 100 calculates the value of the current flowing through the primary conductor 110 by calculating the detection value of the first magnetic sensor 120a and the detection value of the second magnetic sensor 120b. Is provided.
  • the calculation unit 190 is a differential amplifier. However, the calculation unit 190 may be a subtracter.
  • each of the first magnetic member 171 and the second magnetic member 172 includes a first plate-like portion and a second plate-like portion orthogonal to the first plate-like portion. Have. The first plate-like portions of the first magnetic member 171 and the second magnetic member 172 and the primary conductor 110 are positioned in parallel to each other.
  • Each of the two gaps 173 extends from one end of the pair of magnetic members 170 to the other end in the direction in which the current flows through the primary conductor 110 (Y-axis direction).
  • Each of the two gaps 173 is located at a diagonal of a rectangular shape formed by the pair of magnetic members 170 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction).
  • the center position of the rectangular shape formed by the pair of magnetic members 170 and the position of the through hole 110h of the primary conductor 110 overlap. .
  • Each of the first magnetic member 171 and the second magnetic member 172 is made of permalloy, but the material of each of the first magnetic member 171 and the second magnetic member 172 is not limited to permalloy, and is soft. Any magnetic material having high magnetic permeability and saturation magnetic flux density, such as iron steel, silicon steel, electromagnetic steel, nickel alloy, iron alloy, or ferrite, may be used.
  • each of the first magnetic member 171 and the second magnetic member 172 is formed by pressing a thin plate.
  • the formation method of each of the first magnetic member 171 and the second magnetic member 172 is not limited to this, and each of the first magnetic member 171 and the second magnetic member 172 is formed by a method such as cutting or casting. May be.
  • FIG. 7 is a cross-sectional view showing the cross-sectional shape of the primary conductor according to Comparative Example 1.
  • FIG. 8 is a cross-sectional view illustrating the cross-sectional shape of the primary conductor according to the first embodiment.
  • the outer shape of the cross section of the primary conductor 110 was 30 mm wide and 2.5 mm thick.
  • a through hole 110h having a diameter of 2 mm was provided at the center in the width direction of the primary conductor 110 according to the first embodiment.
  • the reference line located immediately above or immediately below the central portion in the width direction of the primary conductor 110 The magnetic flux density distribution on 1 was calculated by simulation analysis.
  • the pair of magnetic members 170 is not disposed.
  • FIG. 9 is a cross-sectional view schematically showing a magnetic field generated around the primary conductor according to the first embodiment.
  • FIG. 10 shows the distance from the front surface or the back surface of the primary conductor and the width direction of the primary conductor on the reference line located immediately above or directly below the central portion in the width direction of the primary conductor according to Comparative Example 1 and Example 1. It is a graph which shows the relationship with the magnetic flux density of (X-axis direction).
  • the vertical axis represents the magnetic flux density (mT)
  • the horizontal axis represents the distance (mm) from the front surface 110s or the back surface 110t of the primary conductor 110.
  • the data of the primary conductor 110 according to the first embodiment is indicated by a solid line
  • the data of the primary conductor 110 according to the comparative example 1 is indicated by a dotted line.
  • the magnetic field 110e is generated by the current 10 flowing through the primary conductor 110 located on the left side of the through hole 110h according to the so-called right-handed screw law. Similarly, a magnetic field 110e is generated by the current 10 flowing through the primary conductor 110 located on the right side of the through hole 110h.
  • LZ and the magnetic flux density RZ in the Z-axis direction due to the magnetic field 110e generated by the current 10 flowing through the primary conductor 110 located on the right side of the through hole 110h cancel each other.
  • the magnetic flux density RX in the X-axis direction due to the generated magnetic field 110e is combined.
  • LZ and the magnetic flux density RZ in the Z-axis direction due to the magnetic field 110e generated by the current 10 flowing through the primary conductor 110 located on the right side of the through hole 110h cancel each other.
  • the magnetic flux density RX in the X-axis direction due to the generated magnetic field 110e is combined.
  • the magnetic flux density in the X-axis direction on the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110 according to Comparative Example 1 is the distance from the surface 110 s of the primary conductor 110. Decreases as the value increases.
  • the magnetic flux density in the X-axis direction on the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110 according to the first embodiment reaches a distance of 4 mm from the surface 110s of the primary conductor 110. The distance increases as the distance increases, and is substantially constant at a position of 4 mm to 10 mm from the surface 110 s of the primary conductor 110.
  • the magnetic flux density in the X-axis direction on the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110 according to Example 1 is the comparative example regardless of the distance from the surface 110s of the primary conductor 110. It is lower than the magnetic flux density in the X-axis direction on the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110. This is because no current flows through the through hole 110h.
  • the magnetic flux density in the X-axis direction on the reference line 1 located immediately below the center in the width direction of the primary conductor 110 according to Comparative Example 1 increases as the distance from the back surface 110t of the primary conductor 110 increases. It is falling.
  • the magnetic flux density in the X-axis direction on the reference line 1 located immediately below the central portion in the width direction of the primary conductor 110 according to the first embodiment reaches a distance of 4 mm from the back surface 110t of the primary conductor 110. The distance increases as the distance increases, and is substantially constant at a position of 4 mm to 10 mm from the back surface 110 t of the primary conductor 110.
  • the magnetic flux density in the X-axis direction on the reference line 1 located immediately below the central portion in the width direction of the primary conductor 110 according to Example 1 is the comparative example regardless of the distance from the back surface 110t of the primary conductor 110. It is lower than the magnetic flux density in the X-axis direction on the reference line 1 located immediately below the central portion in the width direction of the primary conductor 110. This is because no current flows through the through hole 110h.
  • the first magnetic sensor 120a is disposed at a position immediately above the through hole 110h of the primary conductor 110, thereby providing the first magnetic sensor.
  • the magnetic flux density acting on 120a can be reduced. Therefore, even when a large current flows through the primary conductor 110, it is possible to suppress the magnetic saturation of the magnetoresistive element of the first magnetic sensor 120a.
  • the second magnetic sensor 120b by arranging the second magnetic sensor 120b at a position directly below the through hole 110h of the primary conductor 110, the magnetic flux density acting on the second magnetic sensor 120b can be reduced. Therefore, even when a large current flows through the primary conductor 110, it is possible to suppress magnetic saturation of the magnetoresistive element of the second magnetic sensor 120b.
  • FIG. 11 is a graph showing the relationship between the magnetic flux density acting on the magnetoresistive element and the output voltage of the magnetoresistive element.
  • the vertical axis represents the output voltage of the magnetoresistive element
  • the horizontal axis represents the magnetic flux density acting on the magnetoresistive element.
  • the output voltage of the magnetoresistive element increases in proportion to the increase of the magnetic flux density acting on the magnetoresistive element.
  • the output voltage of the magnetoresistive element hardly increases even if the magnetic flux density acting on the magnetoresistive effect element increases.
  • the first magnetism is reduced by reducing the magnetic flux density acting on the magnetoresistive element with a simple structure in which the through hole 110h is provided in the primary conductor 110 without using a complicated circuit.
  • the sensor 120a and the second magnetic sensor 120b can be operated in the first region T 1.
  • the input dynamic range of the current sensor 100 can be expanded, and a large current can be accurately measured by the current sensor 100.
  • the first magnetic sensor 120a is disposed at a position immediately above the through hole 110h of the primary conductor 110
  • the second magnetic sensor 120b is disposed at a position immediately below the through hole 110h of the primary conductor 110, thereby Since the magnetic flux density in the X-axis direction and the Z-axis direction acting on each of the magnetic sensor 120a and the second magnetic sensor 120b can be reduced, the strength of the magnetic field applied to each of the first magnetic sensor 120a and the second magnetic sensor 120b. It is possible to suppress the occurrence of variations. As a result, the current sensor 100 can stably measure the magnitude of the current to be measured.
  • a position of 4 mm to 10 mm from the front surface 110s or the back surface 110t of the primary conductor 110 Is a robust region in which the magnetic flux density in the X-axis direction is substantially constant.
  • the first magnetic sensor 120a is positioned directly above the through hole 110h with the first printed board 130a interposed between the primary conductor 110 and the first magnetic sensor 120a.
  • the sensor 120a is located in the robust area. That is, the thickness of the first printed circuit board 130a is appropriately set so that the first magnetic sensor 120a is positioned in the robust region.
  • the second magnetic sensor 120b is located directly below the through hole 110h with the second printed circuit board 130b sandwiched between the primary conductor 110 and the second magnetic sensor 120b. Is located in the robust region. That is, the thickness of the second printed circuit board 130b is appropriately set so that the second magnetic sensor 120b is located in the robust region.
  • each of the first magnetic sensor 120a and the second magnetic sensor 120b By positioning each of the first magnetic sensor 120a and the second magnetic sensor 120b within the robust region, it is possible to stably cause variations in the strength of the magnetic field applied to each of the first magnetic sensor 120a and the second magnetic sensor 120b. Can be suppressed. As a result, the current sensor 100 can more stably measure the magnitude of the current to be measured.
  • the primary conductor 110 is connected.
  • the phase of the detection value of the first magnetic sensor 120a is opposite to the phase of the detection value of the second magnetic sensor 120b.
  • the strength of the magnetic field detected by the first magnetic sensor 120a is a positive value
  • the strength of the magnetic field detected by the second magnetic sensor 120b is a negative value.
  • the detection value of the first magnetic sensor 120a and the detection value of the second magnetic sensor 120b are transmitted to the calculation unit 190.
  • the calculation unit 190 subtracts the detection value of the second magnetic sensor 120b from the detection value of the first magnetic sensor 120a. As a result, the absolute value of the detection value of the first magnetic sensor 120a and the absolute value of the detection value of the second magnetic sensor 120b are added. From this addition result, the value of the current flowing through the primary conductor 110 is calculated.
  • the primary conductor 110, the first printed board 130a, and the second printed board 130b are located between the first magnetic sensor 120a and the second magnetic sensor 120b.
  • the external magnetic field source cannot be physically located between the first magnetic sensor 120a and the second magnetic sensor 120b.
  • the direction of the magnetic field component in the direction of the detection axis of the magnetic field applied to the first magnetic sensor 120a from the external magnetic field source and the detection axis of the magnetic field applied to the second magnetic sensor 120b from the external magnetic field source is the same direction. Therefore, if the strength of the external magnetic field detected by the first magnetic sensor 120a is a positive value, the strength of the external magnetic field detected by the second magnetic sensor 120b is also a positive value.
  • the calculation unit 190 subtracts the detection value of the second magnetic sensor 120b from the detection value of the first magnetic sensor 120a, thereby detecting the absolute value of the detection value of the first magnetic sensor 120a and the detection of the second magnetic sensor 120b.
  • 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 (opposite 180 °).
  • the strength of the external magnetic field detected by the first magnetic sensor 120a is a positive value
  • the strength of the external magnetic field detected by the second magnetic sensor 120b is a negative value.
  • the phase of the detection value of the first magnetic sensor 120a and the phase of the detection value of the second magnetic sensor 120b are in phase.
  • an adder or an addition amplifier is used as the calculation unit 190 instead of the differential amplifier.
  • the detected value of the first magnetic sensor 120a and the detected value of the second magnetic sensor 120b are added by an adder or an adding amplifier, thereby obtaining the absolute value of the detected value of the first magnetic sensor 120a.
  • the absolute value of the detection value of the second magnetic sensor 120b 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 120a and the detection value of the second magnetic sensor 120b by an adder or an addition amplifier.
  • the absolute value of the detection value of the first magnetic sensor 120a and the absolute value of the detection value of the second magnetic sensor 120b 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 differential amplifier while the input / output characteristics of the first magnetic sensor 120a and the second magnetic sensor 120b have opposite polarities.
  • each of the first magnetic sensor 120 a and the second magnetic sensor 120 b is surrounded by a pair of magnetic members 170.
  • the external magnetic field that is an error factor can be suppressed from reaching each of the first magnetic sensor 120a and the second magnetic sensor 120b.
  • each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field. That is, the pair of magnetic members 170 functions as a magnetic shield.
  • FIG. 12 is a perspective view showing an appearance of the current sensor according to Comparative Example 2.
  • FIG. FIG. 13 is a side view of the current sensor of FIG. 12 as viewed from the direction of the arrow XIII.
  • FIG. 14 is a cross-sectional view of the current sensor of FIG. 13 as viewed from the direction of arrows XIV-XIV.
  • the current sensor 200 includes a pair of magnetic members 270 each having a U-shape when the primary conductor 110 is viewed from the direction in which current flows (Y-axis direction). Is provided.
  • the pair of magnetic members 270 includes a first magnetic member 271 and a second magnetic member 272.
  • the pair of magnetic members 270 has a rectangular shape in which a gap 273 is provided between the ends when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction).
  • the pair of magnetic members 270 includes the first circuit board 160a, the second circuit board 160b, and the portion of the primary conductor 110 sandwiched between the first circuit board 160a and the second circuit board 160b. Is surrounded by a space.
  • Each of the first magnetic member 271 and the second magnetic member 272 is a first plate-like portion and a second plate-like portion and a third plate-like shape that are orthogonal to the first plate-like portion and face each other. Part. The first plate-like portions of the first magnetic member 271 and the second magnetic member 272 and the primary conductor 110 are positioned in parallel to each other.
  • Each of the two air gaps 273 extends from one end of the pair of magnetic members 270 to the other end in the direction in which the current flows through the primary conductor 110 (Y-axis direction).
  • Each of the two gaps 273 is located at the center in the Z-axis direction on both sides of the rectangular shape formed by the pair of magnetic members 270 when viewed from the direction (Y-axis direction) in which the current flowing through the primary conductor 110 flows. is doing.
  • the center position of the rectangular shape formed by the pair of magnetic members 270 and the position of the through hole 110h of the primary conductor 110 overlap each other when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). .
  • FIG. 15 is a perspective view showing an appearance of a current sensor according to Comparative Example 3.
  • FIG. 16 is a plan view of the current sensor of FIG. 15 viewed from the direction of the arrow XVI.
  • FIG. 17 is a cross-sectional view of the current sensor of FIG. 16 viewed from the direction of the arrow XVII-XVII.
  • the current sensor 300 has a pair of magnetic members 370 each having a U shape when the primary conductor 110 is viewed from the direction in which the current flows (Y-axis direction). Is provided.
  • the pair of magnetic members 370 includes a first magnetic member 371 and a second magnetic member 372.
  • the pair of magnetic members 370 has a rectangular shape in which a gap 373 is provided between the ends when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). Surrounding the conductor 110 and the two magnetic sensors.
  • the pair of magnetic members 370 includes a first circuit board 160a, a second circuit board 160b, and a portion of the primary conductor 110 sandwiched between the first circuit board 160a and the second circuit board 160b. Is surrounded by a space.
  • Each of the first magnetic member 371 and the second magnetic member 372 has a first plate-like portion and a second plate-like portion and a third plate-like shape that are orthogonal to the first plate-like portion and face each other. Part. The first plate-like portions of the first magnetic member 371 and the second magnetic member 372 and the primary conductor 110 are positioned in parallel to each other.
  • Each of the two gaps 373 extends from one end of the pair of magnetic members 370 to the other end in the direction in which the current flows through the primary conductor 110 (Y-axis direction).
  • Each of the two air gaps 373 is the center in the X-axis direction of each of the upper and lower sides of the rectangular shape formed by the pair of magnetic members 370 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction).
  • the size of the gaps 173, 273, and 373 was 1 mm.
  • the size of the gaps 173, 273, 373 is the shortest distance between the first magnetic members 171, 271, 371 and the second magnetic members 172, 272, 372.
  • the outer shape of the pair of magnetic members 170, 270, and 370 was 25.0 mm in length, 23.0 mm in width, and 20.0 mm in height.
  • the plate thickness of each of the first magnetic members 171, 271 and 371 and the second magnetic members 172, 272 and 372 was 0.5 mm.
  • the material of each of the first magnetic members 171, 271, 371 and the second magnetic members 172, 272, 372 was 42 alloy (42Ni).
  • the outer dimensions of the primary conductor 110 were 80.0 mm in length, 13.0 mm in width, and 1.5 mm in height.
  • the material of the primary conductor 110 was oxygen-free copper (C1020).
  • FIG. 18 is a schematic diagram showing a state in which a pair of magnetic shields are uniformly magnetized. As shown in FIG. 18, when a current flows through the primary conductor 110 from the front side of the drawing to the back side of the drawing, the pair of magnetic members 170, 270, and 370 are paired with the pair of magnetic members 170, 270. , 370 is magnetized in the direction indicated by arrow 2 so as to circulate clockwise.
  • FIG. 19 is a diagram showing a reference line and a center point in the Z-axis direction in the simulation analysis. As shown in FIG. 19, the magnetic flux density distribution on the reference line 1 located immediately above or directly below the central portion in the width direction of the primary conductor 110 was calculated by simulation analysis. The center position O in the thickness direction of the primary conductor 110 was set as the origin in the Z-axis direction.
  • FIG. 20 shows the center of the primary conductor in the thickness direction on the reference line located immediately above or directly below the central portion in the width direction of the primary conductor in the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3. It is a graph which shows the relationship between the distance from a position, and the magnetic flux density of the width direction (X-axis direction) of a primary conductor.
  • FIG. 21 shows the center in the thickness direction of the primary conductor on the reference line located immediately above or directly below the center portion in the width direction of the primary conductor in the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3. It is a graph which shows the relationship between the distance from a position, and the magnetic flux density of the length direction (Y-axis direction) of a primary conductor.
  • FIG. 22 shows the center in the thickness direction of the primary conductor on the reference line located immediately above or directly below the central portion in the width direction of the primary conductor in the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3. It is a graph which shows the relationship between the distance from a position, and the magnetic flux density of the thickness direction (Z-axis direction) of a primary conductor.
  • the vertical axis represents the normalized magnetic flux density
  • the horizontal axis represents the distance (mm) in the Z-axis direction from the center position O in the thickness direction of the primary conductor 110.
  • the data of the current sensor 100 according to the second embodiment is indicated by a solid line
  • the data of the current sensor 200 according to the comparative example 2 is indicated by a dotted line
  • the data of the current sensor 300 according to the comparative example 3 is indicated by a one-dot chain line. Show.
  • the arrangement positions 121 of the AMR elements of the first magnetic sensor 120a and the second magnetic sensor 120b are shown.
  • each of the current sensor 200 according to the comparative example 2 and the current sensor 300 according to the comparative example 3 includes the first magnetic sensor 120 a and the second magnetic sensor 120 b at the arrangement position 121 of the AMR element.
  • the normalized magnetic flux density Bx in the detection axis direction (X-axis direction) was about 0.3 to 0.5 in absolute value.
  • the normalized magnetic flux density Bx in the detection axis direction (X-axis direction) of each of the first magnetic sensor 120a and the second magnetic sensor 120b is 0 at the AMR element arrangement position 121. .1 or less, which is smaller than the current sensor 200 according to Comparative Example 2 and the current sensor 300 according to Comparative Example 3.
  • each of the current sensor 100 according to the second embodiment, the current sensor 200 according to the second comparative example, and the current sensor 300 according to the third comparative example is arranged in the Y-axis direction at the arrangement position 121 of the AMR element.
  • Each of the normalized magnetic flux density By and the normalized magnetic flux density Bz in the Z-axis direction was substantially 0, and no difference was recognized.
  • FIG. 23 is a graph showing a relationship between an input current value and a sensor output voltage in the current sensor according to the second embodiment.
  • FIG. 24 is a graph showing an enlarged view of the vicinity 3 of the input current value in FIG.
  • FIG. 25 is a graph showing the relationship between the input current value and the sensor output voltage in the current sensor according to Comparative Example 2.
  • FIG. 26 is an enlarged graph showing the vicinity 3 of the input current value 0A in FIG.
  • FIG. 27 is a graph showing the relationship between the input current value and the sensor output voltage in the current sensor according to Comparative Example 3.
  • FIG. 28 is an enlarged graph showing the vicinity 3 of the input current value 0A in FIG. 23 to 28, the vertical axis represents the sensor output voltage (V), and the horizontal axis represents the input current (A).
  • the current sensor 200 according to Comparative Example 2 and the current sensor 300 according to Comparative Example 3 each have an input current value.
  • the sensor output voltage greatly deviated in the vicinity 3 of 0A.
  • the current sensor 100 according to Example 2 when the input current flowing through the primary conductor 110 was swept positively and negatively, no deviation in sensor output voltage was observed in the vicinity 3 of the input current value of 0A.
  • FIG. 29 is a graph showing hysteresis rates of the current sensor 100 according to the second embodiment, the current sensor 200 according to the second comparative example, the current sensor 300 according to the third comparative example, and the current sensor according to the fourth comparative example.
  • the vertical axis represents the hysteresis rate (% FS) and the horizontal axis represents the sample name.
  • the current sensor according to Comparative Example 4 differs from the current sensor according to Example 1 only in that a pair of magnetic members is not provided.
  • the hysteresis rate is a 100-minute ratio of the difference in sensor output voltage when the input current value is 0 A to the sensor output voltage when the input current value is ⁇ 300 A.
  • each of the current sensor 200 according to the comparative example 2 and the current sensor 300 according to the comparative example 3 has a hysteresis rate of 1.8% or more, whereas the current according to the second example.
  • the hysteresis rate was reduced to 0.2%, which was substantially the same as the hysteresis rate of 0.1% of the current sensor according to Comparative Example 4 in which the pair of magnetic members were not provided.
  • each of the two air gaps 173 is 1 as viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction).
  • the first magnetic sensor 120a and the second magnetic sensor 120b are positioned in the robust region, high accuracy is not required for the assembly of the current sensor 100.
  • the sensor 100 can be easily manufactured.
  • the current sensor 400 according to the second embodiment is different from the current sensor according to the first embodiment only in that it further includes another pair of magnetic members, and thus the description of the other configurations will not be repeated.
  • FIG. 30 is a cross-sectional view showing a configuration of a current sensor according to Embodiment 2 of the present invention. 30 is a cross-sectional view of the current sensor as viewed from the same direction as in FIG.
  • the current sensor 400 includes another pair of magnetic elements each having an L shape when the primary conductor 110 is viewed from the direction in which the current flows (Y-axis direction).
  • a body member 470 is further provided.
  • the other pair of magnetic members 470 is composed of a third magnetic member 471 and a fourth magnetic member 472.
  • the other pair of magnetic members 470 has a rectangular shape in which a gap 473 is provided between the ends when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction),
  • the pair of magnetic members 170 is surrounded by a distance from the pair of magnetic members 170.
  • the gaps 473 of the other pair of magnetic members 470 are located outside the corners 171r and 172r of the pair of magnetic members 170, respectively.
  • Each of the third magnetic member 471 and the fourth magnetic member 472 has a third plate-like portion and a fourth plate-like portion orthogonal to the third plate-like portion.
  • the third plate-like portion of each of the third magnetic member 471 and the fourth magnetic member 472 and the primary conductor 110 are positioned in parallel to each other.
  • the third plate-like portion of the third magnetic member 471 and the first plate-like portion of the second magnetic member 172 are located in parallel with a distance from each other.
  • the third plate-like portion of the fourth magnetic body member 472 and each first plate-like portion of the first magnetic body member 171 are positioned in parallel with an interval therebetween.
  • the fourth plate-like portion of the third magnetic member 471 and the second plate-like portion of the first magnetic member 171 are located in parallel with a distance from each other.
  • the fourth plate-like portion of the fourth magnetic body member 472 and each second plate-like portion of the second magnetic body member 172 are positioned in parallel with a space between each other.
  • Each of the two gaps 473 extends from one end of the other pair of magnetic members 470 to the other end in the direction in which the current flows through the primary conductor 110 (Y-axis direction).
  • Each of the two gaps 473 is located at a diagonal of a rectangular shape formed by the other pair of magnetic members 470 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction).
  • the center position of the rectangular shape formed by the other pair of magnetic members 470 overlaps the position of the through hole 110h of the primary conductor 110. ing.
  • Each of the third magnetic member 471 and the fourth magnetic member 472 is made of permalloy, but the material of each of the third magnetic member 471 and the fourth magnetic member 472 is not limited to permalloy, and is soft. Any magnetic material having high magnetic permeability and saturation magnetic flux density, such as iron steel, silicon steel, electromagnetic steel, nickel alloy, iron alloy, or ferrite, may be used.
  • each of the third magnetic member 471 and the fourth magnetic member 472 is formed by pressing a thin plate.
  • the formation method of each of the third magnetic member 471 and the fourth magnetic member 472 is not limited to this, and each of the third magnetic member 471 and the fourth magnetic member 472 is formed by a method such as cutting or casting. May be.
  • each of the first magnetic sensor 120a and the second magnetic sensor 120b includes a pair of magnetic members 170 and another pair of magnetic members 470. Therefore, it is possible to further suppress the external magnetic field, which is an error factor, from reaching each of the first magnetic sensor 120a and the second magnetic sensor 120b. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field. That is, each of the pair of magnetic members 170 and the other pair of magnetic members 470 functions as a magnetic shield.
  • the gaps 473 of the other pair of magnetic members 470 are positioned outside the corners 171r and 172r of the pair of magnetic members 170, so that the first magnetic sensor 120a and the second magnetic member 120a.
  • the sensor 120b can be completely surrounded by a pair of magnetic members 170 and another pair of magnetic members 470. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field.
  • each of the two gaps 173 has a rectangular shape formed by the pair of magnetic members 170 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). By being positioned diagonally, measurement errors due to the magnetic field generated by the residual magnetization of the pair of magnetic members 170 can be reduced.
  • Embodiment 3 of the present invention a current sensor according to Embodiment 3 of the present invention will be described.
  • the current sensor 500 according to the third embodiment is different from the current sensor according to the second embodiment only in that two magnetic sensors are mounted on one printed circuit board, and thus the description of the other configurations will not be repeated.
  • FIG. 31 is a cross-sectional view showing a configuration of a current sensor according to Embodiment 3 of the present invention.
  • FIG. 31 shows in the cross-sectional view which looked at the current sensor from the same direction as FIG.
  • the printed circuit board 530c is held in a state where the primary conductor 110 is inserted into the through hole 530h. That is, the printed circuit board 530 c is positioned perpendicular to the primary conductor 110.
  • the first magnetic sensor 120a and the second magnetic sensor 120b are mounted on a printed circuit board 530c together with a differential amplifier and a passive element.
  • the differential amplifier and the passive element are not shown.
  • the differential amplifier and the passive element may be mounted on a printed board different from the printed board 530c on which the first magnetic sensor 120a and the second magnetic sensor 120b are mounted.
  • the first magnetic sensor 120a and the second magnetic sensor 120b are located on opposite sides of the through hole 530h. Each of the first magnetic sensor 120a and the second magnetic sensor 120b is located at an interval from the through hole 530h.
  • the first magnetic sensor 120a is positioned directly above the through hole 530h, and the second printed circuit board 130b is positioned directly below the through hole 530h. . That is, the first magnetic sensor 120a and the second magnetic sensor 120b are located on opposite sides of the primary conductor 110.
  • each of the first magnetic sensor 120a and the second magnetic sensor 120b is located in the robust region. That is, the interval between each of the first magnetic sensor 120a and the second magnetic sensor 120b and the through hole 530h is appropriately set so that the first magnetic sensor 120a and the second magnetic sensor 120b are positioned in the robust region.
  • the direction (magnetic direction) of the detection axis of each of the first magnetic sensor 120a and the second magnetic sensor 120b is the width direction (X-axis direction) of the primary conductor 110.
  • the magnetic flux density in the X-axis direction, the Y-axis direction, and the Z-axis direction acting on each of the first magnetic sensor 120a and the second magnetic sensor 120b can be reduced. Variations in the strength of the magnetic field applied to the first magnetic sensor 120a and the second magnetic sensor 120b can be suppressed. As a result, the current sensor 500 can stably measure the magnitude of the current to be measured.
  • each of the two gaps 173 has a rectangular shape formed by the pair of magnetic members 170 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). By being positioned diagonally, measurement errors due to the magnetic field generated by the residual magnetization of the pair of magnetic members 170 can be reduced.
  • the gaps 473 of the other pair of magnetic members 470 are positioned outside the corners 171r and 172r of the pair of magnetic members 170, so that the first magnetic sensor 120a and the second magnetic member 120a.
  • the sensor 120b can be completely surrounded by a pair of magnetic members 170 and another pair of magnetic members 470. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field.
  • the current sensor 600 according to the fourth embodiment differs from the current sensor according to the third embodiment only in that the printed circuit board and the magnetic member are configured to be detachable from the primary conductor. Will not repeat the description.
  • FIG. 32 is a cross-sectional view showing a state where a printed circuit board and a magnetic member are attached to a primary conductor in a current sensor according to Embodiment 4 of the present invention.
  • FIG. 33 is a cross-sectional view illustrating a state before the printed circuit board and the magnetic member are attached to the primary conductor in the current sensor according to the fourth embodiment of the present invention. 32 and 33 are shown in a cross-sectional view of the current sensor as viewed from the same direction as in FIG.
  • the first magnetic member 171 of the pair of magnetic members 170 and the other pair of magnetic members 470 As shown in FIGS. 31 and 32, in the current sensor 600 according to the fourth embodiment of the present invention, the first magnetic member 171 of the pair of magnetic members 170 and the other pair of magnetic members 470.
  • the third magnetic body member 471 and the printed board 630c are joined together by a first joining member 681 made of resin or adhesive, and are integrated.
  • the second magnetic member 172 of the pair of magnetic members 170 and the fourth magnetic member 472 of the other pair of magnetic members 470 are made of a resin or an adhesive. They are joined together by 682 and integrated.
  • the peripheral surface of the printed circuit board 630c and the inner surface of the first magnetic member 171 are joined to each other by the first joining member 681.
  • the outer surface of the second plate-like portion of the first magnetic member 171 and the inner surface of the fourth plate-like portion of the third magnetic member 471 facing each other are joined to each other by the first joining member 681.
  • the outer surface of the second plate-like portion of the second magnetic member 172 and the inner surface of the fourth plate-like portion of the fourth magnetic member 472 facing each other are joined to each other by the second joining member 682.
  • a through groove 630h is provided from the end surface side of the peripheral surface of the printed circuit board 630c that is not surrounded by the first magnetic member 171 and the third magnetic member 471 to the opposite end surface.
  • a gap is provided between the printed board 630c and the third plate-like portion of the third magnetic member 471 so that the first plate-like portion of the second magnetic member 172 can be inserted.
  • the primary conductor 110 is inserted into the through groove 630h of the printed board 630c.
  • the printed circuit board 630 c, the first magnetic member 171, and the third magnetic member 471 are moved closer to the primary conductor 110 in the direction indicated by the arrow 61.
  • the first plate-like portion of the second magnetic member 172 is inserted in the direction indicated by the arrow 62 so that the first plate-like portion of the second magnetic member 172 is inserted into the gap between the printed circuit board 630c and the third plate-like portion of the third magnetic member 471.
  • the second magnetic member 172 and the fourth magnetic member 472 are brought closer to the primary conductor 110.
  • the printed circuit board 630c and the magnetic member are attached to the primary conductor 110, the printed circuit board 630c is held with the primary conductor 110 inserted in the through groove 630h. . That is, the printed circuit board 630 c is positioned perpendicular to the primary conductor 110.
  • each of the two gaps 173 and the two gaps 473 is filled with at least one of the first joining member 681 and the second joining member 682.
  • the printed circuit board 630c and the magnetic member are configured to be detachable from the primary conductor 110, so that the assembly and disassembly of the current sensor 600 is easy.
  • each of the two gaps 173 has a rectangular shape formed by a pair of magnetic members 170 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). By being positioned diagonally, measurement errors due to a magnetic field generated by the residual magnetization of the pair of magnetic members 170 can be reduced.
  • the gaps 473 of the other pair of magnetic members 470 are positioned outside the corners 171r and 172r of the pair of magnetic members 170, so that the first magnetic sensor 120a and the second magnetic member 120a.
  • the sensor 120b can be completely surrounded by a pair of magnetic members 170 and another pair of magnetic members 470. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field.

Landscapes

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

Abstract

This current sensor is provided with: a primary conductor (110) in which a current to be measured flows; at least one magnetic sensor (120a, 120b) that detects the strength of a magnetic field generated by means of the current flowing in the primary conductor (110); and a pair of magnetic material members (170), each of which has an L-shape when viewed from the direction in which the current flows. The pair of magnetic material members (170) form a rectangular shape when viewed from the direction in which the current flows, said rectangular shape being provided with gaps (173) between the end portions of respective magnetic material members, and surround the primary conductor (110) and the magnetic sensors (120a, 120b).

Description

電流センサCurrent sensor
　本発明は、電流センサに関し、特に、測定対象の電流に応じて発生する磁界を検出することで測定対象の電流の値を測定する電流センサに関する。 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.
　電流センサの構成を開示した先行文献として、特開２０１０－２２７７号公報(特許文献１)、特開２０１０－８０５０号公報(特許文献２)、特開２０１３－１１４６９号公報(特許文献３)、特開２０１３－２３８５８０号公報(特許文献４)、特開２０１３－２２８３１５号公報(特許文献５)、および、特開２００１－２８１２７０号公報(特許文献６)がある。 As prior documents disclosing the configuration of the current sensor, JP 2010-2277 A (Patent Document 1), JP 2010-8050 A (Patent Document 2), JP 2013-11469 A (Patent Document 3), JP 2013-238580 A (Patent Document 4), JP 2013-228315 A (Patent Document 5), and JP 2001-281270 A (Patent Document 6).
　特許文献１に記載された電流センサは、Ｕ相、Ｖ相およびＷ相の各々について、バスバーと、絶縁基板と、磁気検出素子としてのホールＩＣと、磁気シールド体とを備える。磁気シールド体は、上側磁気シールド部材および下側磁気シールド部材によって、バスバーと絶縁基板とホールＩＣとを環状に囲む環状囲み部を構成することで、外部磁界から磁気遮蔽するものである。上側磁気シールド部材および下側磁気シールド部材の間に空隙が形成されている。空隙の高さ方向の位置は、バスバーの高さ方向の位置と同じまたは近傍であり、バスバーの側面と対向する部分に空隙が位置している。ホールＩＣはバスバーの中央部の上方に配置されている。 The current sensor described in Patent Document 1 includes a bus bar, an insulating substrate, a Hall IC as a magnetic detection element, and a magnetic shield for each of the U phase, the V phase, and the W phase. In the magnetic shield body, the upper magnetic shield member and the lower magnetic shield member form an annular enclosure that annularly surrounds the bus bar, the insulating substrate, and the Hall IC, thereby magnetically shielding the external magnetic field. A gap is formed between the upper magnetic shield member and the lower magnetic shield member. The position in the height direction of the gap is the same as or near the position in the height direction of the bus bar, and the gap is located at a portion facing the side surface of the bus bar. The Hall IC is arranged above the central portion of the bus bar.
　特許文献２に記載された電流センサは、特許文献１に記載された電流センサの構成に加えて、非磁性スペーサを備える。磁気シールド体の空隙に非磁性スペーサの凸条が係合している。これにより、空隙スリットの間隔は凸条にて一定に規制されている。 The current sensor described in Patent Document 2 includes a nonmagnetic spacer in addition to the configuration of the current sensor described in Patent Document 1. The protrusions of the nonmagnetic spacer are engaged with the gaps of the magnetic shield body. Thereby, the space | interval of a space | gap slit is controlled uniformly by the protruding item | line.
　特許文献３に記載された電流センサは、形成面に磁気抵抗効果素子が形成されているセンサ基板と、被測定電流が流れる被測定導体と、センサ基板および被測定導体の周囲を囲む磁気シールド部とを有する。磁気シールド部には、磁気シールド部内の磁気飽和を抑制するための２つの空隙が形成されており、磁気シールド部内を流れる磁束は空隙にて放出される。磁気シールド部における対称な構造を成す部位に、空隙が形成されている。ｚ方向における、空隙の高さ位置と、センサ基板の高さ位置とが同一である。 The current sensor described in Patent Document 3 includes a sensor substrate on which a magnetoresistive effect element is formed, a measured conductor through which a measured current flows, and a magnetic shield portion that surrounds the sensor substrate and the measured conductor. And have. Two gaps for suppressing magnetic saturation in the magnetic shield part are formed in the magnetic shield part, and the magnetic flux flowing in the magnetic shield part is released in the gap. An air gap is formed at a portion of the magnetic shield portion having a symmetrical structure. The height position of the air gap and the height position of the sensor substrate in the z direction are the same.
　特許文献４に記載された電流センサは、被測定電流が流れる導体であるバスバーと、感磁素子としてのホールＩＣと、ホールＩＣを外部磁界から磁気遮蔽する対をなす第１および第２の磁性体とを有している。対をなす第１および第２の磁性体の両端縁は空隙を隔てて対向している。 The current sensor described in Patent Document 4 includes a bus bar that is a conductor through which a current to be measured flows, a Hall IC as a magnetosensitive element, and first and second magnets that form a pair that magnetically shields the Hall IC from an external magnetic field. Have a body. Both ends of the first and second magnetic bodies forming a pair are opposed to each other with a gap.
　特許文献５に記載された電流センサは、バスバーと、メインコアと、サブコアと、感磁素子とを備える。メインコアは、ギャップを有する環状(Ｃ型)であり、バスバーが貫通する。サブコアは、Ｕ型(半環状)であって端面がメインコアのギャップの近傍に位置し、メインコアと非接触でメインコアと同一平面内にあり、メインコアの漏洩磁束の一部が流れる。感磁素子は、ホール素子であり、メインコアのギャップ内であってメインコアの残留磁化により発生する磁界とサブコアの残留磁化により発生する磁界とが弱め合う位置に存在する。 The current sensor described in Patent Document 5 includes a bus bar, a main core, a sub core, and a magnetosensitive element. The main core has an annular shape (C-type) with a gap, and the bus bar passes therethrough. The sub-core is U-shaped (semi-annular) and its end face is located in the vicinity of the gap of the main core, is in non-contact with the main core and is in the same plane as the main core, and a part of the leakage flux of the main core flows. The magnetosensitive element is a Hall element, and exists in a position where the magnetic field generated by the residual magnetization of the main core and the magnetic field generated by the residual magnetization of the sub core are weakened in the gap of the main core.
　特許文献６に記載された電流センサは、電流センサ本体と、内側磁気シールドケースと、外側磁気シールドケースとを備える。内側磁気シールドケースの分割方向と、外側磁気シールドケースの分割方向とは互いに交差している。内側磁気シールドケースは、電流センサ本体の周りを囲み、外側磁気シールドケースは、内側磁気シールドケースの周りを囲んでいる。 The current sensor described in Patent Document 6 includes a current sensor body, an inner magnetic shield case, and an outer magnetic shield case. The dividing direction of the inner magnetic shield case and the dividing direction of the outer magnetic shield case intersect each other. The inner magnetic shield case surrounds the current sensor body, and the outer magnetic shield case surrounds the inner magnetic shield case.
特開２０１０－２２７７号公報JP 2010-2277 A 特開２０１０－８０５０号公報JP 2010-8050 A 特開２０１３－１１４６９号公報JP 2013-11469 A 特開２０１３－２３８５８０号公報JP 2013-238580 A 特開２０１３－２２８３１５号公報JP 2013-228315 A 特開２００１－２８１２７０号公報JP 2001-281270 A
　特許文献１，２に記載された電流センサにおいては、磁化した磁気シールド体の残留磁化により発生する磁界の影響により、バスバーを流れる電流が０Ａの状態においてもセンサ出力が発生し、測定誤差が生じる。 In the current sensors described in Patent Documents 1 and 2, due to the influence of the magnetic field generated by the residual magnetization of the magnetized magnetic shield body, the sensor output is generated even when the current flowing through the bus bar is 0 A, resulting in a measurement error. .
　特許文献３，４，６に記載された電流センサにおいては、特許文献１，２に記載された電流センサより、磁気シールド体の残留磁化により発生する磁界の影響は小さくなるが、不十分である。 In the current sensors described in Patent Documents 3, 4, and 6, the influence of the magnetic field generated by the residual magnetization of the magnetic shield body is smaller than that of the current sensors described in Patent Documents 1 and 2, but is insufficient. .
　特許文献５に記載された電流センサにおいては、特許文献１，２に記載された電流センサより、磁気シールド体の残留磁化により発生する磁界の影響は小さくなるが、メインコアとサブコアと感磁素子とを適切な位置に配置する必要があり、高い組み立て精度が求められ、電流センサの製造が困難である。 In the current sensor described in Patent Document 5, the influence of the magnetic field generated by the residual magnetization of the magnetic shield body is smaller than that of the current sensors described in Patent Documents 1 and 2, but the main core, the sub-core, and the magnetosensitive element. Are required to be arranged at appropriate positions, high assembly accuracy is required, and the manufacture of the current sensor is difficult.
　本発明は上記の問題点に鑑みてなされたものであって、残留磁化により発生する磁界による測定誤差が低減されつつ容易に製造可能な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 the above problems, and an object of the present invention is to provide a current sensor that can be easily manufactured while reducing a measurement error due to a magnetic field generated by residual magnetization.
　本発明に基づく電流センサは、測定対象の電流が流れる１次導体と、１次導体を流れる上記電流により発生する磁界の強さを検出する少なくとも１つの磁気センサと、上記電流が流れる方向から見て、それぞれＬ字形状を有する１対の磁性体部材とを備える。１対の磁性体部材は、上記電流が流れる方向から見て、互いの端部同士の間に空隙が設けられた矩形形状を成し、１次導体および磁気センサの周りを囲んでいる。 A current sensor according to the present invention includes a primary conductor through which a current to be measured flows, at least one magnetic sensor for detecting the strength of a magnetic field generated by the current flowing through the primary conductor, and a direction in which the current flows. And a pair of magnetic members each having an L shape. The pair of magnetic members has a rectangular shape in which a gap is provided between the ends when viewed from the direction in which the current flows, and surrounds the primary conductor and the magnetic sensor.
　本発明の一形態においては、１次導体は、平板形状を有する。磁気センサは、１次導体の厚さ方向および上記電流が流れる方向の両方と直交する方向の磁界を検出可能とされている。 In one embodiment of the present invention, the primary conductor has a flat plate shape. The magnetic sensor can detect a magnetic field in a direction orthogonal to both the thickness direction of the primary conductor and the direction in which the current flows.
　本発明の一形態においては、磁気センサは、１次導体の幅方向における中央部の、１次導体の厚さ方向における一方側および他方側の少なくとも一方に配置されている。 In one embodiment of the present invention, the magnetic sensor is disposed at least one of the one side and the other side in the thickness direction of the primary conductor in the central portion in the width direction of the primary conductor.
　本発明の一形態においては、電流センサは、磁気センサとして第１磁気センサと第２磁気センサとを備える。第１磁気センサと第２磁気センサとは、１次導体を挟んで互いに対向して位置している。 In one embodiment of the present invention, the current sensor includes a first magnetic sensor and a second magnetic sensor as magnetic sensors. The first magnetic sensor and the second magnetic sensor are positioned to face each other with the primary conductor interposed therebetween.
　本発明の一形態においては、電流センサは、第１磁気センサの検出値と第２磁気センサの検出値とを演算することにより上記電流の値を算出する算出部をさらに備える。１次導体を流れる上記電流により発生する磁界の強さについて、第１磁気センサの検出値の位相と第２磁気センサの検出値の位相とが逆相である。算出部が減算器または差動増幅器である。 In one embodiment of the present invention, 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.
　本発明の一形態においては、電流センサは、第１磁気センサの検出値と第２磁気センサの検出値とを演算することにより上記電流の値を算出する算出部をさらに備える。１次導体を流れる上記電流により発生する磁界の強さについて、第１磁気センサの検出値の位相と第２磁気センサの検出値の位相とが同相である。算出部が加算器または加算増幅器である。 In one embodiment of the present invention, 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.
　本発明の一形態においては、電流センサは、上記電流が流れる方向から見て、それぞれＬ字形状を有する他の１対の磁性体部材とをさらに備える。他の１対の磁性体部材は、上記電流が流れる方向から見て、互いの端部同士の間に空隙が設けられた矩形形状を成し、１対の磁性体部材に対して間隔を置いて１対の磁性体部材の周りを囲んでいる。他の１対の磁性体部材の空隙は、１対の磁性体部材の各々の角部の外側に位置している。 In one embodiment of the present invention, the current sensor further includes another pair of magnetic members each having an L shape when viewed from the direction in which the current flows. The other pair of magnetic members has a rectangular shape with a gap provided between the ends when viewed from the direction in which the current flows, and is spaced from the pair of magnetic members. Surrounding a pair of magnetic members. The gaps of the other pair of magnetic members are located outside the corners of each pair of magnetic members.
　本発明によれば、残留磁化により発生する磁界による測定誤差が低減された電流センサを容易に製造できる。 According to the present invention, it is possible to easily manufacture a current sensor in which a measurement error due to a magnetic field generated by residual magnetization is reduced.
本発明の実施形態１に係る電流センサの外観を示す斜視図である。It is a perspective view which shows the external appearance of the current sensor which concerns on Embodiment 1 of this invention. 図１の電流センサを矢印ＩＩ方向から見た側面図である。It is the side view which looked at the current sensor of Drawing 1 from the direction of arrow II. 図２の電流センサをＩＩＩ－ＩＩＩ線矢印方向から見た断面図である。FIG. 3 is a cross-sectional view of the current sensor of FIG. 2 as viewed from the direction of arrows III-III. 本発明の実施形態１に係る電流センサの構成を示す分解斜視図である。It is a disassembled perspective view which shows the structure of the current sensor which concerns on Embodiment 1 of this invention. 本発明の実施形態１に係る電流センサの回路基板の外観を示す斜視図である。It is a perspective view which shows the external appearance of the circuit board of the current sensor which concerns on Embodiment 1 of this invention. 本発明の実施形態１に係る電流センサの回路構成を示す回路図である。It is a circuit diagram which shows the circuit structure of the current sensor which concerns on Embodiment 1 of this invention. 比較例１に係る１次導体の横断面形状を示す断面図である。6 is a cross-sectional view showing a cross-sectional shape of a primary conductor according to Comparative Example 1. FIG. 実施例１に係る１次導体の横断面形状を示す断面図である。3 is a cross-sectional view showing a cross-sectional shape of a primary conductor according to Example 1. FIG. 実施例１に係る１次導体の周囲に発生する磁界を模式的に示す断面図である。3 is a cross-sectional view schematically showing a magnetic field generated around a primary conductor according to Example 1. FIG. 比較例１および実施例１に係る１次導体の幅方向の中央部の直上または直下に位置する基準線上における、１次導体の表面または裏面からの距離と１次導体の幅方向(Ｘ軸方向)の磁束密度との関係を示すグラフである。The distance from the front surface or the back surface of the primary conductor and the width direction of the primary conductor (X-axis direction) on the reference line located immediately above or directly below the central portion in the width direction of the primary conductor according to Comparative Example 1 and Example 1 ) Is a graph showing the relationship with the magnetic flux density. 磁気抵抗素子に作用する磁束密度と磁気抵抗素子の出力電圧との関係を示すグラフである。It is a graph which shows the relationship between the magnetic flux density which acts on a magnetoresistive element, and the output voltage of a magnetoresistive element. 比較例２に係る電流センサの外観を示す斜視図である。It is a perspective view which shows the external appearance of the current sensor which concerns on the comparative example 2. FIG. 図１２の電流センサを矢印ＸＩＩＩ方向から見た側面図である。It is the side view which looked at the current sensor of FIG. 12 from the arrow XIII direction. 図１３の電流センサをＸＩＶ－ＸＩＶ線矢印方向から見た断面図である。It is sectional drawing which looked at the current sensor of FIG. 13 from the XIV-XIV line arrow direction. 比較例３に係る電流センサの外観を示す斜視図である。14 is a perspective view illustrating an appearance of a current sensor according to Comparative Example 3. FIG. 図１５の電流センサを矢印ＸＶＩ方向から見た平面図である。It is the top view which looked at the current sensor of FIG. 15 from the arrow XVI direction. 図１６の電流センサをＸＶＩＩ－ＸＶＩＩ線矢印方向から見た断面図である。FIG. 17 is a cross-sectional view of the current sensor of FIG. 16 as viewed from the direction of the arrow XVII-XVII. １対の磁気シールドが一様に磁化した状態を示す模式図である。It is a mimetic diagram showing the state where a pair of magnetic shields were uniformly magnetized. シミュレーション解析におけるＺ軸方向の基準線および中心点を示す図である。It is a figure which shows the reference line and center point of the Z-axis direction in simulation analysis. 実施例２、比較例２および比較例３に係る電流センサにおいて、１次導体の幅方向の中央部の直上または直下に位置する基準線上における、１次導体の厚さ方向の中心位置からの距離と１次導体の幅方向(Ｘ軸方向)の磁束密度との関係を示すグラフである。In the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3, the distance from the center position in the thickness direction of the primary conductor on the reference line located immediately above or directly below the center portion in the width direction of the primary conductor 5 is a graph showing the relationship between the magnetic flux density in the width direction (X-axis direction) of the primary conductor. 実施例２、比較例２および比較例３に係る電流センサにおいて、１次導体の幅方向の中央部の直上または直下に位置する基準線上における、１次導体の厚さ方向の中心位置からの距離と１次導体の長さ方向(Ｙ軸方向)の磁束密度との関係を示すグラフである。In the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3, the distance from the center position in the thickness direction of the primary conductor on the reference line located immediately above or directly below the center portion in the width direction of the primary conductor 5 is a graph showing the relationship between the magnetic flux density in the length direction (Y-axis direction) of the primary conductor. 実施例２、比較例２および比較例３に係る電流センサにおいて、１次導体の幅方向の中央部の直上または直下に位置する基準線上における、１次導体の厚さ方向の中心位置からの距離と１次導体の厚さ方向(Ｚ軸方向)の磁束密度との関係を示すグラフである。In the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3, the distance from the center position in the thickness direction of the primary conductor on the reference line located immediately above or directly below the center portion in the width direction of the primary conductor 5 is a graph showing the relationship between the magnetic flux density in the thickness direction (Z-axis direction) of the primary conductor. 実施例２に係る電流センサにおける入力電流値とセンサ出力電圧との関係を示すグラフである。It is a graph which shows the relationship between the input electric current value in the current sensor which concerns on Example 2, and a sensor output voltage. 図２３における入力電流値の０Ａ近傍部３を拡大して示すグラフである。It is a graph which expands and shows the 0A vicinity part 3 of the input current value in FIG. 比較例２に係る電流センサにおける入力電流値とセンサ出力電圧との関係を示すグラフである。It is a graph which shows the relationship between the input electric current value in the current sensor which concerns on the comparative example 2, and a sensor output voltage. 図２５における入力電流値の０Ａ近傍部３を拡大して示すグラフである。It is a graph which expands and shows the 0A vicinity part 3 of the input current value in FIG. 比較例３に係る電流センサにおける入力電流値とセンサ出力電圧との関係を示すグラフである。12 is a graph showing a relationship between an input current value and a sensor output voltage in a current sensor according to Comparative Example 3. 図２７における入力電流値の０Ａ近傍部３を拡大して示すグラフである。It is a graph which expands and shows the 0A vicinity part 3 of the input current value in FIG. 実施例２に係る電流センサ１００、比較例２に係る電流センサ２００、比較例３に係る電流センサ３００、比較例４に係る電流センサの各々のヒステリシス率を示すグラフである。10 is a graph showing hysteresis rates of a current sensor 100 according to Example 2, a current sensor 200 according to Comparative Example 2, a current sensor 300 according to Comparative Example 3, and a current sensor according to Comparative Example 4. 本発明の実施形態２に係る電流センサの構成を示す断面図である。It is sectional drawing which shows the structure of the current sensor which concerns on Embodiment 2 of this invention. 本発明の実施形態３に係る電流センサの構成を示す断面図である。It is sectional drawing which shows the structure of the current sensor which concerns on Embodiment 3 of this invention. 本発明の実施形態４に係る電流センサにおいて、プリント基板および磁性体部材を１次導体に対して取り付けた状態を示す断面図である。In the current sensor according to Embodiment 4 of the present invention, it is a cross-sectional view showing a state where a printed board and a magnetic member are attached to a primary conductor. 本発明の実施形態４に係る電流センサにおいて、プリント基板および磁性体部材を１次導体に対して取り付ける前の状態を示す断面図である。In the current sensor according to Embodiment 4 of the present invention, it is a cross-sectional view showing a state before the printed board and the magnetic member are attached to the primary conductor.
　以下、本発明の各実施形態に係る電流センサについて図を参照して説明する。以下の実施形態の説明においては、図中の同一または相当部分には同一符号を付して、その説明は繰り返さない。 Hereinafter, the current sensor according to each embodiment of the present invention will be described with reference to the drawings. In the following description of the embodiments, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.
　(実施形態１)
　図１は、本発明の実施形態１に係る電流センサの外観を示す斜視図である。図２は、図１の電流センサを矢印ＩＩ方向から見た側面図である。図３は、図２の電流センサをＩＩＩ－ＩＩＩ線矢印方向から見た断面図である。図４は、本発明の実施形態１に係る電流センサの構成を示す分解斜視図である。図５は、本発明の実施形態１に係る電流センサの回路基板の外観を示す斜視図である。図６は、本発明の実施形態１に係る電流センサの回路構成を示す回路図である。図１～３においては、後述する１次導体１１０の幅方向をＸ軸方向、１次導体１１０の長さ方向をＹ軸方向、１次導体１１０の厚さ方向をＺ軸方向として、図示している。 (Embodiment 1)
FIG. 1 is a perspective view showing an appearance of a current sensor according to Embodiment 1 of the present invention. FIG. 2 is a side view of the current sensor of FIG. 1 viewed from the direction of arrow II. FIG. 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 an exploded perspective view showing the configuration of the current sensor according to Embodiment 1 of the present invention. FIG. 5 is a perspective view showing an appearance of a circuit board of the current sensor according to the first embodiment of the present invention. FIG. 6 is a circuit diagram showing a circuit configuration of the current sensor according to Embodiment 1 of the present invention. 1 to 3, the width direction of a primary conductor 110, which will be described later, is illustrated as an X-axis direction, the length direction of the primary conductor 110 is defined as a Y-axis direction, and the thickness direction of the primary conductor 110 is illustrated as a Z-axis direction. ing.
　図１～６に示すように、本発明の実施形態１に係る電流センサ１００は、測定対象の電流が流れる１次導体１１０と、１次導体１１０を流れる電流により発生する磁界の強さを検出する２つの磁気センサとを備える。２つの磁気センサは、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂから構成されている。本実施形態においては、電流センサ１００は、２つの磁気センサを備えているが、これに限られず、少なくとも１つの磁気センサを備えていればよい。 As shown in FIGS. 1 to 6, the current sensor 100 according to the first embodiment of the present invention detects the primary conductor 110 through which the current to be measured flows and the strength of the magnetic field generated by the current through the primary conductor 110. Two magnetic sensors. The two magnetic sensors are composed of a first magnetic sensor 120a and a second magnetic sensor 120b. In the present embodiment, the current sensor 100 includes two magnetic sensors. However, the present invention is not limited to this, and it is only necessary to include at least one magnetic sensor.
　さらに、電流センサ１００は、１次導体１１０を電流が流れる方向(Ｙ軸方向)から見て、それぞれＬ字形状を有する１対の磁性体部材１７０を備える。具体的には、１対の磁性体部材１７０は、第１磁性体部材１７１および第２磁性体部材１７２から構成されている。１対の磁性体部材１７０は、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、互いの端部同士の間に空隙１７３が設けられた矩形形状を成し、１次導体１１０および２つの磁気センサの周りを囲んでいる。具体的には、１対の磁性体部材１７０は、後述する、第１回路基板１６０ａ、第２回路基板１６０ｂ、および、第１回路基板１６０ａと第２回路基板１６０ｂとに挟まれた部分の１次導体１１０に対して間隔を置いて周りを囲んでいる。 Furthermore, the current sensor 100 includes a pair of magnetic members 170 each having an L shape when the primary conductor 110 is viewed from the direction in which current flows (Y-axis direction). Specifically, the pair of magnetic members 170 includes a first magnetic member 171 and a second magnetic member 172. The pair of magnetic members 170 has a rectangular shape in which a gap 173 is provided between ends of each other when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). Surrounding the conductor 110 and the two magnetic sensors. Specifically, the pair of magnetic members 170 includes a first circuit board 160a, a second circuit board 160b, and a portion sandwiched between the first circuit board 160a and the second circuit board 160b, which will be described later. It surrounds the second conductor 110 with a space.
　１次導体１１０、第１回路基板１６０ａ、第２回路基板１６０ｂ、および、１対の磁性体部材１７０の各々の相対位置は、図示しないケースなどにより維持されている。ケースは、ポリフェニレンスルファイドなどの高温耐性を有するエンジニアリングプラスティックなどで形成されていることが好ましい。第１回路基板１６０ａおよび第２回路基板１６０ｂの各々とケースとをネジにより締結する場合には、磁場の乱れが生じないように、非磁性材料からなるネジで締結されていることが好ましい。 The relative positions of the primary conductor 110, the first circuit board 160a, the second circuit board 160b, and the pair of magnetic members 170 are maintained by a case (not shown). The case is preferably formed of an engineering plastic having high temperature resistance such as polyphenylene sulfide. When each of the first circuit board 160a and the second circuit board 160b and the case are fastened with screws, it is preferably fastened with screws made of a non-magnetic material so as not to disturb the magnetic field.
　以下、各構成について詳細に説明する。
　本実施形態においては、１次導体１１０は、平板形状を有している。１次導体１１０は、１次導体１１０の表面から裏面まで貫通した１つの貫通部を有している。具体的には、１次導体１１０の幅方向における中央部に、平面視にて円形の貫通孔１１０ｈが設けられている。電流は、１次導体１１０をＹ軸方向に流れる。 Hereinafter, each configuration will be described in detail.
In the present embodiment, the primary conductor 110 has a flat plate shape. The primary conductor 110 has one penetrating portion that penetrates from the front surface to the back surface of the primary conductor 110. Specifically, a circular through hole 110h is provided in a central portion in the width direction of the primary conductor 110 in a plan view. The current flows through the primary conductor 110 in the Y-axis direction.
　本実施形態においては、１次導体１１０は、銅で構成されている。ただし、１次導体１１０の材料はこれに限られず、銀、アルミニウムなどの金属またはこれらの金属を含む合金でもよい。１次導体１１０は、表面処理が施されていてもよい。たとえば、ニッケル、錫、銀、銅などの金属またはこれらの金属を含む合金からなる、少なくとも１層のめっき層が、１次導体１１０の表面に設けられていてもよい。 In the present embodiment, the primary conductor 110 is made of copper. However, the material of the primary conductor 110 is not limited to this, and may be a metal such as silver or aluminum or an alloy containing these metals. The primary conductor 110 may be subjected to 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.
　本実施形態においては、薄板をプレス加工することにより１次導体１１０が形成されている。ただし、１次導体１１０の形成方法はこれに限られず、切削または鋳造などの方法によって１次導体１１０が形成されてもよい。 In the present embodiment, the primary conductor 110 is formed by pressing a thin plate. However, 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 cutting or casting.
　本実施形態においては、第１磁気センサ１２０ａは、第１オペアンプ１４０ａおよび第１受動素子１５０ａとともに第１プリント基板１３０ａに実装されている。第１磁気センサ１２０ａは、第１プリント基板１３０ａの中央に配置されている。第１磁気センサ１２０ａ、第１プリント基板１３０ａ、第１オペアンプ１４０ａおよび第１受動素子１５０ａは、第１回路基板１６０ａを構成している。第１プリント基板１３０ａは、ガラスエポキシまたはアルミナからなる基板、および、基板上に銅箔などの金属箔がパターニングされて形成された配線を含む。第１回路基板１６０ａには、第１磁気センサ１２０ａからの信号を演算する演算回路が構成されている。 In the present embodiment, the first magnetic sensor 120a is mounted on the first printed circuit board 130a together with the first operational amplifier 140a and the first passive element 150a. The first magnetic sensor 120a is disposed at the center of the first printed circuit board 130a. The first magnetic sensor 120a, the first printed board 130a, the first operational amplifier 140a, and the first passive element 150a constitute a first circuit board 160a. The first printed circuit board 130a includes a substrate made of glass epoxy or alumina, and wiring formed by patterning a metal foil such as a copper foil on the substrate. The first circuit board 160a is configured with an arithmetic circuit that calculates a signal from the first magnetic sensor 120a.
　第２磁気センサ１２０ｂは、第２オペアンプ１４０ｂおよび第２受動素子１５０ｂとともに第２プリント基板１３０ｂに実装されている。第２磁気センサ１２０ｂは、第２プリント基板１３０ｂの中央に配置されている。第２磁気センサ１２０ｂ、第２プリント基板１３０ｂ、第２オペアンプ１４０ｂおよび第２受動素子１５０ｂは、第２回路基板１６０ｂを構成している。第２プリント基板１３０ｂは、ガラスエポキシまたはアルミナからなる基板、および、基板上に銅箔などの金属箔がパターニングされて形成された配線を含む。第２回路基板１６０ｂには、第２磁気センサ１２０ｂからの信号を演算する演算回路が構成されている。 The second magnetic sensor 120b is mounted on the second printed circuit board 130b together with the second operational amplifier 140b and the second passive element 150b. The second magnetic sensor 120b is disposed at the center of the second printed circuit board 130b. The second magnetic sensor 120b, the second printed board 130b, the second operational amplifier 140b, and the second passive element 150b constitute a second circuit board 160b. Second printed circuit board 130b includes a substrate made of glass epoxy or alumina, and a wiring formed by patterning a metal foil such as a copper foil on the substrate. The second circuit board 160b is configured with an arithmetic circuit that calculates a signal from the second magnetic sensor 120b.
　第１回路基板１６０ａは、１次導体１１０の表面上に載置されている。第１磁気センサ１２０ａは、第１プリント基板１３０ａを１次導体１１０との間に挟んで、貫通孔１１０ｈの直上に位置している。第２回路基板１６０ｂは、１次導体１１０の裏面上に配置されている。第２磁気センサ１２０ｂは、第２プリント基板１３０ｂを１次導体１１０との間に挟んで、貫通孔１１０ｈの直下に位置している。 The first circuit board 160a is placed on the surface of the primary conductor 110. The first magnetic sensor 120a is located immediately above the through hole 110h with the first printed board 130a sandwiched between the primary conductor 110. The second circuit board 160 b is disposed on the back surface of the primary conductor 110. The second magnetic sensor 120b is located directly below the through hole 110h with the second printed board 130b sandwiched between the primary conductor 110.
　すなわち、第１磁気センサ１２０ａと第２磁気センサ１２０ｂとは、１次導体１１０を挟んで互いに反対側に位置している。第１磁気センサ１２０ａは、１次導体１１０の幅方向(Ｘ軸方向)における中央部の、１次導体１１０の厚さ方向(Ｚ軸方向)における一方側(上方側)に配置されている。第２磁気センサ１２０ｂは、１次導体１１０の幅方向(Ｘ軸方向)における中央部の、１次導体１１０の厚さ方向(Ｚ軸方向)における他方側(下方側)に配置されている。 That is, the first magnetic sensor 120a and the second magnetic sensor 120b are located on opposite sides of the primary conductor 110. The first magnetic sensor 120 a is disposed on one side (upper side) in the thickness direction (Z-axis direction) of the primary conductor 110 in the central portion in the width direction (X-axis direction) of the primary conductor 110. The second magnetic sensor 120b is disposed on the other side (lower side) in the thickness direction (Z-axis direction) of the primary conductor 110 at the center in the width direction (X-axis direction) of the primary conductor 110.
　第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々の検出軸の方向(感磁方向)は、１次導体１１０の幅方向(Ｘ軸方向)である。すなわち、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々は、１次導体１１０の厚さ方向(Ｚ軸方向)および１次導体１１０を電流が流れる方向(Ｙ軸方向)の両方と直交する方向(Ｘ軸方向)の磁界を検出可能とされている。 The direction (magnetic direction) of the detection axis of each of the first magnetic sensor 120a and the second magnetic sensor 120b is the width direction (X-axis direction) of the primary conductor 110. That is, each of the first magnetic sensor 120a and the second magnetic sensor 120b is orthogonal to both the thickness direction (Z-axis direction) of the primary conductor 110 and the direction in which the current flows through the primary conductor 110 (Y-axis direction). The magnetic field in the direction (X-axis direction) can be detected.
　第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々は、検出軸の一方向に向いた磁界を検出した場合に正の値で出力し、かつ、検出軸の一方向とは反対方向に向いた磁界を検出した場合に負の値で出力する、入出力特性を有している。 Each of the first magnetic sensor 120a and the second magnetic sensor 120b outputs a positive value when a magnetic field directed in one direction of the detection axis is detected, and is directed in a direction opposite to the one direction of the detection axis. It has an input / output characteristic that outputs a negative value when a magnetic field is detected.
　第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々は、４つのＡＭＲ(Anisotropic　Magneto　Resistance)素子からなるホイートストンブリッジ型のブリッジ回路を有する。なお、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々が、ＡＭＲ素子に代えて、ＧＭＲ(Giant　Magneto　Resistance)、ＴＭＲ(Tunnel　Magneto　Resistance)、ＢＭＲ(Balistic　Magneto　Resistance)、ＣＭＲ(Colossal　Magneto　Resistance)などの磁気抵抗素子を有していてもよい。また、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々が、２つの磁気抵抗素子からなるハーフ・ブリッジ回路を有していてもよい。その他にも、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂとして、ホール素子を有する磁気センサ、磁気インピーダンス効果を利用するＭＩ(Magneto　Impedance)素子を有する磁気センサまたはフラックスゲート型磁気センサなどを用いることができる。磁気抵抗素子およびホール素子などの磁気素子は、樹脂パッケージされていてもよく、または、シリコーン樹脂若しくはエポキシ樹脂などでポッティングされていてもよい。 Each of the first magnetic sensor 120a and the second magnetic sensor 120b has a Wheatstone bridge type bridge circuit including four AMR (Anisotropic Magneto Resistance) elements. Each of the first magnetic sensor 120a and the second magnetic sensor 120b is replaced with an AMR element, and GMR (Giant Magneto Resistance), TMR (Tunnel Magneto Resistance), BMR (Balistic Magneto Resistance), CMR (Colossal Magneto Resistance). It may have a magnetoresistive element. Further, each of the first magnetic sensor 120a and the second magnetic sensor 120b may have a half bridge circuit including two magnetoresistive elements. In addition, as the first magnetic sensor 120a and the second magnetic sensor 120b, 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. Magnetic elements such as a magnetoresistive element and a Hall element may be packaged with a resin, or may be potted with a silicone resin or an epoxy resin.
　第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々のＡＭＲ素子は、バーバーポール型電極を含むことによって、奇関数入出力特性を有している。具体的には、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々のＡＭＲ素子は、バーバーポール型電極を含むことにより、所定の角度に電流が流れるようにバイアスされている。第１磁気センサ１２０ａのＡＭＲ素子における磁気抵抗膜の磁化方向と、第２磁気センサ１２０ｂのＡＭＲ素子における磁気抵抗膜の磁化方向とは、同一方向である。これにより、外部磁界の影響による出力精度の低下を小さくすることができる。 Each AMR element of the first magnetic sensor 120a and the second magnetic sensor 120b has an odd function input / output characteristic by including a barber pole type electrode. Specifically, each AMR element of the first magnetic sensor 120a and the second magnetic sensor 120b includes a barber pole type electrode, and is biased so that a current flows at a predetermined angle. The magnetization direction of the magnetoresistive film in the AMR element of the first magnetic sensor 120a and the magnetization direction of the magnetoresistive film in the AMR element of the second magnetic sensor 120b are the same direction. Thereby, the fall of the output accuracy by the influence of an external magnetic field can be made small.
　図６に示すように、電流センサ１００は、第１磁気センサ１２０ａの検出値と第２磁気センサ１２０ｂの検出値とを演算することにより１次導体１１０を流れる電流の値を算出する算出部１９０を備える。算出部１９０は、差動増幅器である。ただし、算出部１９０が減算器であってもよい。 As shown in FIG. 6, the current sensor 100 calculates the value of the current flowing through the primary conductor 110 by calculating the detection value of the first magnetic sensor 120a and the detection value of the second magnetic sensor 120b. Is provided. The calculation unit 190 is a differential amplifier. However, the calculation unit 190 may be a subtracter.
　図１～３に示すように、第１磁性体部材１７１および第２磁性体部材１７２の各々は、第１板状部と、第１板状部に直交している第２板状部とを有している。第１磁性体部材１７１および第２磁性体部材１７２の各々の第１板状部と１次導体１１０とは、互いに平行に位置している。 As shown in FIGS. 1 to 3, each of the first magnetic member 171 and the second magnetic member 172 includes a first plate-like portion and a second plate-like portion orthogonal to the first plate-like portion. Have. The first plate-like portions of the first magnetic member 171 and the second magnetic member 172 and the primary conductor 110 are positioned in parallel to each other.
　２つの空隙１７３の各々は、１次導体１１０を電流が流れる方向(Ｙ軸方向)において、１対の磁性体部材１７０の一端から他端まで延在している。２つの空隙１７３の各々は、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材１７０が成す矩形形状の対角に位置している。１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材１７０が成す矩形形状の中心位置と、１次導体１１０の貫通孔１１０ｈの位置とは重なっている。 Each of the two gaps 173 extends from one end of the pair of magnetic members 170 to the other end in the direction in which the current flows through the primary conductor 110 (Y-axis direction). Each of the two gaps 173 is located at a diagonal of a rectangular shape formed by the pair of magnetic members 170 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). When viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction), the center position of the rectangular shape formed by the pair of magnetic members 170 and the position of the through hole 110h of the primary conductor 110 overlap. .
　第１磁性体部材１７１および第２磁性体部材１７２の各々は、パーマロイで構成されているが、第１磁性体部材１７１および第２磁性体部材１７２の各々の材料は、パーマロイに限られず、軟鉄鋼、ケイ素鋼、電磁鋼、ニッケル合金、鉄合金またはフェライトなどの、透磁率および飽和磁束密度の高い磁性体材料であればよい。 Each of the first magnetic member 171 and the second magnetic member 172 is made of permalloy, but the material of each of the first magnetic member 171 and the second magnetic member 172 is not limited to permalloy, and is soft. Any magnetic material having high magnetic permeability and saturation magnetic flux density, such as iron steel, silicon steel, electromagnetic steel, nickel alloy, iron alloy, or ferrite, may be used.
　本実施形態においては、薄板をプレス加工することにより第１磁性体部材１７１および第２磁性体部材１７２の各々が形成されている。ただし、第１磁性体部材１７１および第２磁性体部材１７２の各々の形成方法はこれに限られず、切削または鋳造などの方法によって第１磁性体部材１７１および第２磁性体部材１７２の各々が形成されてもよい。 In the present embodiment, each of the first magnetic member 171 and the second magnetic member 172 is formed by pressing a thin plate. However, the formation method of each of the first magnetic member 171 and the second magnetic member 172 is not limited to this, and each of the first magnetic member 171 and the second magnetic member 172 is formed by a method such as cutting or casting. May be.
　ここで、貫通部を有さない比較例１の１次導体１１０、および、貫通孔１１０ｈが設けられた実施例１の１次導体１１０について、１次導体１１０の幅方向(Ｘ軸方向)における中央部の直上または直下の位置における、１次導体１１０の表面１１０ｓまたは裏面１１０ｔからの距離と磁束密度との関係をシミュレーション解析した結果について説明する。 Here, in the width direction (X-axis direction) of the primary conductor 110 with respect to the primary conductor 110 of Comparative Example 1 that does not have a through portion and the primary conductor 110 of Example 1 in which the through hole 110h is provided. The result of simulation analysis of the relationship between the distance from the front surface 110s or the back surface 110t of the primary conductor 110 and the magnetic flux density at a position immediately above or directly below the center will be described.
　図７は、比較例１に係る１次導体の横断面形状を示す断面図である。図８は、実施例１に係る１次導体の横断面形状を示す断面図である。図７，８に示すように、比較例１および実施例１において、１次導体１１０の横断面の外形は、幅３０ｍｍ、厚さ２．５ｍｍとした。実施例１に係る１次導体１１０の幅方向の中央部に、直径２ｍｍの貫通孔１１０ｈを設けた。比較例１および実施例１において、１次導体１１０を流れる電流の値を１００Ａとして、図７，８に示すように、１次導体１１０の幅方向の中央部の直上または直下に位置する基準線１上における磁束密度分布をシミュレーション解析により算出した。なお、比較例１および実施例１においては、１対の磁性体部材１７０は配置していない。 FIG. 7 is a cross-sectional view showing the cross-sectional shape of the primary conductor according to Comparative Example 1. FIG. 8 is a cross-sectional view illustrating the cross-sectional shape of the primary conductor according to the first embodiment. As shown in FIGS. 7 and 8, in Comparative Example 1 and Example 1, the outer shape of the cross section of the primary conductor 110 was 30 mm wide and 2.5 mm thick. A through hole 110h having a diameter of 2 mm was provided at the center in the width direction of the primary conductor 110 according to the first embodiment. In Comparative Example 1 and Example 1, assuming that the value of the current flowing through the primary conductor 110 is 100A, as shown in FIGS. 7 and 8, the reference line located immediately above or immediately below the central portion in the width direction of the primary conductor 110 The magnetic flux density distribution on 1 was calculated by simulation analysis. In Comparative Example 1 and Example 1, the pair of magnetic members 170 is not disposed.
　図９は、実施例１に係る１次導体の周囲に発生する磁界を模式的に示す断面図である。図９においては、図８と同一の断面視にて図示している。図１０は、比較例１および実施例１に係る１次導体の幅方向の中央部の直上または直下に位置する基準線上における、１次導体の表面または裏面からの距離と１次導体の幅方向(Ｘ軸方向)の磁束密度との関係を示すグラフである。図１０においては、縦軸に磁束密度(ｍＴ)、横軸に１次導体１１０の表面１１０ｓまたは裏面１１０ｔからの距離(ｍｍ)を示している。また、図１０においては、実施例１に係る１次導体１１０のデータを実線で、比較例１に係る１次導体１１０のデータを点線で示している。 FIG. 9 is a cross-sectional view schematically showing a magnetic field generated around the primary conductor according to the first embodiment. In FIG. 9, the same sectional view as FIG. 8 is shown. FIG. 10 shows the distance from the front surface or the back surface of the primary conductor and the width direction of the primary conductor on the reference line located immediately above or directly below the central portion in the width direction of the primary conductor according to Comparative Example 1 and Example 1. It is a graph which shows the relationship with the magnetic flux density of (X-axis direction). In FIG. 10, the vertical axis represents the magnetic flux density (mT), and the horizontal axis represents the distance (mm) from the front surface 110s or the back surface 110t of the primary conductor 110. In FIG. 10, the data of the primary conductor 110 according to the first embodiment is indicated by a solid line, and the data of the primary conductor 110 according to the comparative example 1 is indicated by a dotted line.
　図９に示すように、いわゆる右ねじの法則によって、貫通孔１１０ｈの左側に位置する１次導体１１０を流れる電流１０により磁界１１０ｅが発生する。同様に、貫通孔１１０ｈの右側に位置する１次導体１１０を流れる電流１０により磁界１１０ｅが発生する。 As shown in FIG. 9, the magnetic field 110e is generated by the current 10 flowing through the primary conductor 110 located on the left side of the through hole 110h according to the so-called right-handed screw law. Similarly, a magnetic field 110e is generated by the current 10 flowing through the primary conductor 110 located on the right side of the through hole 110h.
　１次導体１１０の幅方向の中央部の直上に位置する基準線１上においては、貫通孔１１０ｈの左側に位置する１次導体１１０を流れる電流１０により発生した磁界１１０ｅによるＺ軸方向の磁束密度ＬＺと、貫通孔１１０ｈの右側に位置する１次導体１１０を流れる電流１０により発生した磁界１１０ｅによるＺ軸方向の磁束密度ＲＺとが、打ち消し合う。一方、貫通孔１１０ｈの左側に位置する１次導体１１０を流れる電流１０により発生した磁界１１０ｅによるＸ軸方向の磁束密度ＬＸと、貫通孔１１０ｈの右側に位置する１次導体１１０を流れる電流１０により発生した磁界１１０ｅによるＸ軸方向の磁束密度ＲＸとが、組み合わされる。 On the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110, the magnetic flux density in the Z-axis direction due to the magnetic field 110e generated by the current 10 flowing through the primary conductor 110 located on the left side of the through hole 110h. LZ and the magnetic flux density RZ in the Z-axis direction due to the magnetic field 110e generated by the current 10 flowing through the primary conductor 110 located on the right side of the through hole 110h cancel each other. On the other hand, the magnetic flux density LX in the X-axis direction due to the magnetic field 110e generated by the current 10 flowing through the primary conductor 110 located on the left side of the through hole 110h and the current 10 flowing through the primary conductor 110 located on the right side of the through hole 110h. The magnetic flux density RX in the X-axis direction due to the generated magnetic field 110e is combined.
　１次導体１１０の幅方向の中央部の直下に位置する基準線１上においては、貫通孔１１０ｈの左側に位置する１次導体１１０を流れる電流１０により発生した磁界１１０ｅによるＺ軸方向の磁束密度ＬＺと、貫通孔１１０ｈの右側に位置する１次導体１１０を流れる電流１０により発生した磁界１１０ｅによるＺ軸方向の磁束密度ＲＺとが、打ち消し合う。一方、貫通孔１１０ｈの左側に位置する１次導体１１０を流れる電流１０により発生した磁界１１０ｅによるＸ軸方向の磁束密度ＬＸと、貫通孔１１０ｈの右側に位置する１次導体１１０を流れる電流１０により発生した磁界１１０ｅによるＸ軸方向の磁束密度ＲＸとが、組み合わされる。 On the reference line 1 located immediately below the central portion in the width direction of the primary conductor 110, the magnetic flux density in the Z-axis direction due to the magnetic field 110e generated by the current 10 flowing through the primary conductor 110 located on the left side of the through hole 110h. LZ and the magnetic flux density RZ in the Z-axis direction due to the magnetic field 110e generated by the current 10 flowing through the primary conductor 110 located on the right side of the through hole 110h cancel each other. On the other hand, the magnetic flux density LX in the X-axis direction due to the magnetic field 110e generated by the current 10 flowing through the primary conductor 110 located on the left side of the through hole 110h and the current 10 flowing through the primary conductor 110 located on the right side of the through hole 110h. The magnetic flux density RX in the X-axis direction due to the generated magnetic field 110e is combined.
　図１０に示すように、比較例１に係る１次導体１１０の幅方向の中央部の直上に位置する基準線１上におけるＸ軸方向の磁束密度は、１次導体１１０の表面１１０ｓからの距離が大きくなるに従って低下している。一方、実施例１に係る１次導体１１０の幅方向の中央部の直上に位置する基準線１上におけるＸ軸方向の磁束密度は、１次導体１１０の表面１１０ｓからの距離が４ｍｍに到達するまでは距離が大きくなるに従って増加し、１次導体１１０の表面１１０ｓから４ｍｍ以上１０ｍｍ以下の位置においては略一定になっている。 As shown in FIG. 10, the magnetic flux density in the X-axis direction on the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110 according to Comparative Example 1 is the distance from the surface 110 s of the primary conductor 110. Decreases as the value increases. On the other hand, the magnetic flux density in the X-axis direction on the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110 according to the first embodiment reaches a distance of 4 mm from the surface 110s of the primary conductor 110. The distance increases as the distance increases, and is substantially constant at a position of 4 mm to 10 mm from the surface 110 s of the primary conductor 110.
　実施例１に係る１次導体１１０の幅方向の中央部の直上に位置する基準線１上におけるＸ軸方向の磁束密度は、１次導体１１０の表面１１０ｓからの距離に関わらず、比較例に係る１次導体１１０の幅方向の中央部の直上に位置する基準線１上におけるＸ軸方向の磁束密度より低くなっている。これは、貫通孔１１０ｈの部分に、電流が流れていないためである。 The magnetic flux density in the X-axis direction on the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110 according to Example 1 is the comparative example regardless of the distance from the surface 110s of the primary conductor 110. It is lower than the magnetic flux density in the X-axis direction on the reference line 1 located immediately above the central portion in the width direction of the primary conductor 110. This is because no current flows through the through hole 110h.
　同様に、比較例１に係る１次導体１１０の幅方向の中央部の直下に位置する基準線１上におけるＸ軸方向の磁束密度は、１次導体１１０の裏面１１０ｔからの距離が大きくなるに従って低下している。一方、実施例１に係る１次導体１１０の幅方向の中央部の直下に位置する基準線１上におけるＸ軸方向の磁束密度は、１次導体１１０の裏面１１０ｔからの距離が４ｍｍに到達するまでは距離が大きくなるに従って増加し、１次導体１１０の裏面１１０ｔから４ｍｍ以上１０ｍｍ以下の位置においては略一定になっている。 Similarly, the magnetic flux density in the X-axis direction on the reference line 1 located immediately below the center in the width direction of the primary conductor 110 according to Comparative Example 1 increases as the distance from the back surface 110t of the primary conductor 110 increases. It is falling. On the other hand, the magnetic flux density in the X-axis direction on the reference line 1 located immediately below the central portion in the width direction of the primary conductor 110 according to the first embodiment reaches a distance of 4 mm from the back surface 110t of the primary conductor 110. The distance increases as the distance increases, and is substantially constant at a position of 4 mm to 10 mm from the back surface 110 t of the primary conductor 110.
　実施例１に係る１次導体１１０の幅方向の中央部の直下に位置する基準線１上におけるＸ軸方向の磁束密度は、１次導体１１０の裏面１１０ｔからの距離に関わらず、比較例に係る１次導体１１０の幅方向の中央部の直下に位置する基準線１上におけるＸ軸方向の磁束密度より低くなっている。これは、貫通孔１１０ｈの部分に、電流が流れていないためである。 The magnetic flux density in the X-axis direction on the reference line 1 located immediately below the central portion in the width direction of the primary conductor 110 according to Example 1 is the comparative example regardless of the distance from the back surface 110t of the primary conductor 110. It is lower than the magnetic flux density in the X-axis direction on the reference line 1 located immediately below the central portion in the width direction of the primary conductor 110. This is because no current flows through the through hole 110h.
　このシミュレーション解析の結果から分かるように、本実施形態に係る電流センサ１００においては、第１磁気センサ１２０ａを、１次導体１１０の貫通孔１１０ｈの直上の位置に配置することにより、第１磁気センサ１２０ａに作用する磁束密度を低減することができる。よって、１次導体１１０に大電流が流れた場合においても、第１磁気センサ１２０ａの磁気抵抗素子が磁気飽和することを抑制することができる。 As can be seen from the result of the simulation analysis, in the current sensor 100 according to the present embodiment, the first magnetic sensor 120a is disposed at a position immediately above the through hole 110h of the primary conductor 110, thereby providing the first magnetic sensor. The magnetic flux density acting on 120a can be reduced. Therefore, even when a large current flows through the primary conductor 110, it is possible to suppress the magnetic saturation of the magnetoresistive element of the first magnetic sensor 120a.
　同様に、第２磁気センサ１２０ｂを、１次導体１１０の貫通孔１１０ｈの直下の位置に配置することにより、第２磁気センサ１２０ｂに作用する磁束密度を低減することができる。よって、１次導体１１０に大電流が流れた場合においても、第２磁気センサ１２０ｂの磁気抵抗素子が磁気飽和することを抑制することができる。 Similarly, by arranging the second magnetic sensor 120b at a position directly below the through hole 110h of the primary conductor 110, the magnetic flux density acting on the second magnetic sensor 120b can be reduced. Therefore, even when a large current flows through the primary conductor 110, it is possible to suppress magnetic saturation of the magnetoresistive element of the second magnetic sensor 120b.
　図１１は、磁気抵抗素子に作用する磁束密度と磁気抵抗素子の出力電圧との関係を示すグラフである。図１１においては、縦軸に磁気抵抗素子の出力電圧、横軸に磁気抵抗素子に作用する磁束密度を示している。 FIG. 11 is a graph showing the relationship between the magnetic flux density acting on the magnetoresistive element and the output voltage of the magnetoresistive element. In FIG. 11, the vertical axis represents the output voltage of the magnetoresistive element, and the horizontal axis represents the magnetic flux density acting on the magnetoresistive element.
　図１１に示すように、磁気抵抗素子が磁気飽和していない第１領域Ｔ1においては、磁気抵抗素子に作用する磁束密度の増加に比例して磁気抵抗素子の出力電圧が増加する。磁気抵抗素子が磁気飽和している第２領域Ｔ2においては、磁気抵抗効果素子に作用する磁束密度が増加しても磁気抵抗素子の出力電圧はほとんど増加しない。 As shown in FIG. 11, in the first region T 1 where the magnetoresistive element is not magnetically saturated, the output voltage of the magnetoresistive element increases in proportion to the increase of the magnetic flux density acting on the magnetoresistive element. In the second region T 2 where the magnetoresistive element is magnetically saturated, the output voltage of the magnetoresistive element hardly increases even if the magnetic flux density acting on the magnetoresistive effect element increases.
　本実施形態に係る電流センサ１００においては、複雑な回路によらずに１次導体１１０に貫通孔１１０ｈを設けた簡易な構造で磁気抵抗素子に作用する磁束密度を低減することにより、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂを第１領域Ｔ1にて動作させることができる。その結果、電流センサ１００の入力ダイナミックレンジを拡大させることができ、電流センサ１００によって大電流を正確に測定することが可能となる。 In the current sensor 100 according to the present embodiment, the first magnetism is reduced by reducing the magnetic flux density acting on the magnetoresistive element with a simple structure in which the through hole 110h is provided in the primary conductor 110 without using a complicated circuit. the sensor 120a and the second magnetic sensor 120b can be operated in the first region T 1. As a result, the input dynamic range of the current sensor 100 can be expanded, and a large current can be accurately measured by the current sensor 100.
　また、第１磁気センサ１２０ａを１次導体１１０の貫通孔１１０ｈの直上の位置に配置し、第２磁気センサ１２０ｂを１次導体１１０の貫通孔１１０ｈの直下の位置に配置することにより、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々に作用するＸ軸方向およびＺ軸方向の磁束密度を低減することができるため、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々に加わる磁界の強度にばらつきが生ずることを抑制できる。その結果、電流センサ１００によって被測定電流の大きさを安定して測定することができる。 In addition, the first magnetic sensor 120a is disposed at a position immediately above the through hole 110h of the primary conductor 110, and the second magnetic sensor 120b is disposed at a position immediately below the through hole 110h of the primary conductor 110, thereby Since the magnetic flux density in the X-axis direction and the Z-axis direction acting on each of the magnetic sensor 120a and the second magnetic sensor 120b can be reduced, the strength of the magnetic field applied to each of the first magnetic sensor 120a and the second magnetic sensor 120b. It is possible to suppress the occurrence of variations. As a result, the current sensor 100 can stably measure the magnitude of the current to be measured.
　上記のように、実施例１に係る１次導体１１０の幅方向の中央部の直上または直下に位置する基準線１上において、１次導体１１０の表面１１０ｓまたは裏面１１０ｔから４ｍｍ以上１０ｍｍ以下の位置は、Ｘ軸方向の磁束密度が略一定になっているロバスト領域である。 As described above, on the reference line 1 located immediately above or directly below the central portion in the width direction of the primary conductor 110 according to the first embodiment, a position of 4 mm to 10 mm from the front surface 110s or the back surface 110t of the primary conductor 110. Is a robust region in which the magnetic flux density in the X-axis direction is substantially constant.
　本実施形態に係る電流センサ１００においては、第１磁気センサ１２０ａが、第１プリント基板１３０ａを１次導体１１０との間に挟んで、貫通孔１１０ｈの直上に位置していることにより第１磁気センサ１２０ａがロバスト領域内に位置している。すなわち、第１磁気センサ１２０ａがロバスト領域内に位置するように、第１プリント基板１３０ａの厚さを適宜設定している。 In the current sensor 100 according to the present embodiment, the first magnetic sensor 120a is positioned directly above the through hole 110h with the first printed board 130a interposed between the primary conductor 110 and the first magnetic sensor 120a. The sensor 120a is located in the robust area. That is, the thickness of the first printed circuit board 130a is appropriately set so that the first magnetic sensor 120a is positioned in the robust region.
　同様に、電流センサ１００においては、第２磁気センサ１２０ｂが、第２プリント基板１３０ｂを１次導体１１０との間に挟んで、貫通孔１１０ｈの直下に位置していることにより第２磁気センサ１２０ｂがロバスト領域内に位置している。すなわち、第２磁気センサ１２０ｂがロバスト領域内に位置するように、第２プリント基板１３０ｂの厚さを適宜設定している。 Similarly, in the current sensor 100, the second magnetic sensor 120b is located directly below the through hole 110h with the second printed circuit board 130b sandwiched between the primary conductor 110 and the second magnetic sensor 120b. Is located in the robust region. That is, the thickness of the second printed circuit board 130b is appropriately set so that the second magnetic sensor 120b is located in the robust region.
　第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々をロバスト領域内に位置させることにより、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々に加わる磁界の強度にばらつきが生ずることを安定して抑制できる。その結果、電流センサ１００によって被測定電流の大きさをさらに安定して測定することができる。 By positioning each of the first magnetic sensor 120a and the second magnetic sensor 120b within the robust region, it is possible to stably cause variations in the strength of the magnetic field applied to each of the first magnetic sensor 120a and the second magnetic sensor 120b. Can be suppressed. As a result, the current sensor 100 can more stably measure the magnitude of the current to be measured.
　図９に示すように、第１磁気センサ１２０ａに作用するＸ軸方向の磁束の向きと、第２磁気センサ１２０ｂに作用するＸ軸方向磁束の向きとが反対であるため、１次導体１１０を流れる電流により発生する磁界の強さについて、第１磁気センサ１２０ａの検出値の位相と、第２磁気センサ１２０ｂの検出値の位相とは、逆相である。 As shown in FIG. 9, since the direction of the magnetic flux in the X-axis direction acting on the first magnetic sensor 120a is opposite to the direction of the magnetic flux in the X-axis direction acting on the second magnetic sensor 120b, the primary conductor 110 is connected. Regarding the strength of the magnetic field generated by the flowing current, the phase of the detection value of the first magnetic sensor 120a is opposite to the phase of the detection value of the second magnetic sensor 120b.
　よって、第１磁気センサ１２０ａの検出した磁界の強さを正の値とすると、第２磁気センサ１２０ｂの検出した磁界の強さは負の値となる。第１磁気センサ１２０ａの検出値と第２磁気センサ１２０ｂの検出値とは、算出部１９０に送信される。 Therefore, if the strength of the magnetic field detected by the first magnetic sensor 120a is a positive value, the strength of the magnetic field detected by the second magnetic sensor 120b is a negative value. The detection value of the first magnetic sensor 120a and the detection value of the second magnetic sensor 120b are transmitted to the calculation unit 190.
　算出部１９０は、第１磁気センサ１２０ａの検出値から第２磁気センサ１２０ｂの検出値を減算する。その結果、第１磁気センサ１２０ａの検出値の絶対値と、第２磁気センサ１２０ｂの検出値の絶対値とが加算される。この加算結果から、１次導体１１０を流れた電流の値が算出される。 The calculation unit 190 subtracts the detection value of the second magnetic sensor 120b from the detection value of the first magnetic sensor 120a. As a result, the absolute value of the detection value of the first magnetic sensor 120a and the absolute value of the detection value of the second magnetic sensor 120b are added. From this addition result, the value of the current flowing through the primary conductor 110 is calculated.
　本実施形態に係る電流センサ１００においては、第１磁気センサ１２０ａと第２磁気センサ１２０ｂとの間に、１次導体１１０、第１プリント基板１３０ａ、および第２プリント基板１３０ｂが位置しているため、外部磁界源は、物理的に第１磁気センサ１２０ａと第２磁気センサ１２０ｂとの間に位置することができない。 In the current sensor 100 according to the present embodiment, the primary conductor 110, the first printed board 130a, and the second printed board 130b are located between the first magnetic sensor 120a and the second magnetic sensor 120b. The external magnetic field source cannot be physically located between the first magnetic sensor 120a and the second magnetic sensor 120b.
　そのため、外部磁界源から第１磁気センサ１２０ａに印加される磁界のうちの検出軸の方向における磁界成分の向きと、外部磁界源から第２磁気センサ１２０ｂに印加される磁界のうちの検出軸の方向における磁界成分の向きとは、同じ向きとなる。よって、第１磁気センサ１２０ａの検出した外部磁界の強さを正の値とすると、第２磁気センサ１２０ｂの検出した外部磁界の強さも正の値となる。 Therefore, the direction of the magnetic field component in the direction of the detection axis of the magnetic field applied to the first magnetic sensor 120a from the external magnetic field source and the detection axis of the magnetic field applied to the second magnetic sensor 120b from the external magnetic field source. The direction of the magnetic field component in the direction is the same direction. Therefore, if the strength of the external magnetic field detected by the first magnetic sensor 120a is a positive value, the strength of the external magnetic field detected by the second magnetic sensor 120b is also a positive value.
　その結果、算出部１９０が第１磁気センサ１２０ａの検出値から第２磁気センサ１２０ｂの検出値を減算することにより、第１磁気センサ１２０ａの検出値の絶対値と、第２磁気センサ１２０ｂの検出値の絶対値とが減算される。これにより、外部磁界源からの磁界は、ほとんど検出されなくなる。すなわち、外部磁界の影響が低減される。 As a result, the calculation unit 190 subtracts the detection value of the second magnetic sensor 120b from the detection value of the first magnetic sensor 120a, thereby detecting the absolute value of the detection value of the first magnetic sensor 120a and the detection of the second magnetic sensor 120b. 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.
　本実施形態の変形例として、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂにおいて、検出値が正となる検出軸の方向を互いに反対方向(１８０°反対)にしてもよい。この場合、第１磁気センサ１２０ａの検出する外部磁界の強さを正の値とすると、第２磁気センサ１２０ｂの検出する外部磁界の強さは負の値となる。 As a modification of the present embodiment, in the first magnetic sensor 120a and the second magnetic sensor 120b, the directions of the detection axes with positive detection values may be opposite to each other (opposite 180 °). In this case, if the strength of the external magnetic field detected by the first magnetic sensor 120a is a positive value, the strength of the external magnetic field detected by the second magnetic sensor 120b is a negative value.
　一方、１次導体１１０を流れる電流により発生する磁界の強さについて、第１磁気センサ１２０ａの検出値の位相と、第２磁気センサ１２０ｂの検出値の位相とは同相となる。 On the other hand, regarding 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 120a and the phase of the detection value of the second magnetic sensor 120b are in phase.
　本変形例においては、算出部１９０として差動増幅器に代えて加算器または加算増幅器を用いる。外部磁界の強さについては、第１磁気センサ１２０ａの検出値と第２磁気センサ１２０ｂの検出値とを加算器または加算増幅器によって加算することにより、第１磁気センサ１２０ａの検出値の絶対値と、第２磁気センサ１２０ｂの検出値の絶対値とが減算される。これにより、外部磁界源からの磁界は、ほとんど検出されなくなる。すなわち、外部磁界の影響が低減される。 In this modification, an adder or an addition amplifier is used as the calculation unit 190 instead of the differential amplifier. Regarding the strength of the external magnetic field, the detected value of the first magnetic sensor 120a and the detected value of the second magnetic sensor 120b are added by an adder or an adding amplifier, thereby obtaining the absolute value of the detected value of the first magnetic sensor 120a. The absolute value of the detection value of the second magnetic sensor 120b 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.
　一方、１次導体１１０を流れる電流により発生する磁界の強さについては、第１磁気センサ１２０ａの検出値と第２磁気センサ１２０ｂの検出値とを加算器または加算増幅器によって加算することにより、第１磁気センサ１２０ａの検出値の絶対値と、第２磁気センサ１２０ｂの検出値の絶対値とが加算される。この加算結果から、１次導体１１０を流れた電流の値が算出される。 On the other hand, 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 120a and the detection value of the second magnetic sensor 120b by an adder or an addition amplifier. The absolute value of the detection value of the first magnetic sensor 120a and the absolute value of the detection value of the second magnetic sensor 120b are added. From this addition result, the value of the current flowing through the primary conductor 110 is calculated.
　このように、第１磁気センサ１２０ａと第２磁気センサ１２０ｂとの入出力特性を互いに逆の極性にしつつ、差動増幅器に代えて加算器または加算増幅器を算出部として用いてもよい。 As described above, an adder or an addition amplifier may be used as the calculation unit in place of the differential amplifier while the input / output characteristics of the first magnetic sensor 120a and the second magnetic sensor 120b have opposite polarities.
　図１，３に示すように、本実施形態に係る電流センサ１００においては、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々は、１対の磁性体部材１７０に周りを囲まれているため、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々に誤差要因である外部磁界が到達することを抑制できる。その結果、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々が、不要な外部磁界を検知しないようにすることができる。すなわち、１対の磁性体部材１７０は、磁気シールドとして機能する。 As shown in FIGS. 1 and 3, in the current sensor 100 according to this embodiment, each of the first magnetic sensor 120 a and the second magnetic sensor 120 b is surrounded by a pair of magnetic members 170. The external magnetic field that is an error factor can be suppressed from reaching each of the first magnetic sensor 120a and the second magnetic sensor 120b. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field. That is, the pair of magnetic members 170 functions as a magnetic shield.
　ここで、１対の磁性体部材における空隙の位置の影響を検証したシミュレーション解析結果および実測結果について説明する。本検証例においては、図１～６に示す構成を有する実施例２に係る電流センサ、後述する比較例２に係る電流センサ、および、比較例３に係る電流センサの３種類の電流センサについて検証を行なった。なお、以下の比較例２および比較例３に係る電流センサの説明においては、実施例２に係る電流センサと異なる点のみ説明し、実施例２に係る電流センサと同様である構成については説明を繰り返さない。 Here, a simulation analysis result and an actual measurement result in which the influence of the position of the air gap in the pair of magnetic members is verified will be described. In this verification example, three types of current sensors are verified: a current sensor according to Example 2 having the configuration shown in FIGS. 1 to 6, a current sensor according to Comparative Example 2 to be described later, and a current sensor according to Comparative Example 3. Was done. In the following description of the current sensor according to Comparative Example 2 and Comparative Example 3, only the differences from the current sensor according to Example 2 will be described, and the configuration similar to that of the current sensor according to Example 2 will be described. Do not repeat.
　図１２は、比較例２に係る電流センサの外観を示す斜視図である。図１３は、図１２の電流センサを矢印ＸＩＩＩ方向から見た側面図である。図１４は、図１３の電流センサをＸＩＶ－ＸＩＶ線矢印方向から見た断面図である。 FIG. 12 is a perspective view showing an appearance of the current sensor according to Comparative Example 2. FIG. FIG. 13 is a side view of the current sensor of FIG. 12 as viewed from the direction of the arrow XIII. FIG. 14 is a cross-sectional view of the current sensor of FIG. 13 as viewed from the direction of arrows XIV-XIV.
　図１２～１４に示すように、比較例２に係る電流センサ２００は、１次導体１１０を電流が流れる方向(Ｙ軸方向)から見て、それぞれＵ字形状を有する１対の磁性体部材２７０を備える。具体的には、１対の磁性体部材２７０は、第１磁性体部材２７１および第２磁性体部材２７２から構成されている。１対の磁性体部材２７０は、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、互いの端部同士の間に空隙２７３が設けられた矩形形状を成し、１次導体１１０および２つの磁気センサの周りを囲んでいる。具体的には、１対の磁性体部材２７０は、第１回路基板１６０ａ、第２回路基板１６０ｂ、および、第１回路基板１６０ａと第２回路基板１６０ｂとに挟まれた部分の１次導体１１０に対して間隔を置いて周りを囲んでいる。 As shown in FIGS. 12 to 14, the current sensor 200 according to Comparative Example 2 includes a pair of magnetic members 270 each having a U-shape when the primary conductor 110 is viewed from the direction in which current flows (Y-axis direction). Is provided. Specifically, the pair of magnetic members 270 includes a first magnetic member 271 and a second magnetic member 272. The pair of magnetic members 270 has a rectangular shape in which a gap 273 is provided between the ends when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). Surrounding the conductor 110 and the two magnetic sensors. Specifically, the pair of magnetic members 270 includes the first circuit board 160a, the second circuit board 160b, and the portion of the primary conductor 110 sandwiched between the first circuit board 160a and the second circuit board 160b. Is surrounded by a space.
　第１磁性体部材２７１および第２磁性体部材２７２の各々は、第１板状部と、第１板状部にそれぞれ直交して互いに対向している、第２板状部および第３板状部とを有している。第１磁性体部材２７１および第２磁性体部材２７２の各々の第１板状部と１次導体１１０とは、互いに平行に位置している。 Each of the first magnetic member 271 and the second magnetic member 272 is a first plate-like portion and a second plate-like portion and a third plate-like shape that are orthogonal to the first plate-like portion and face each other. Part. The first plate-like portions of the first magnetic member 271 and the second magnetic member 272 and the primary conductor 110 are positioned in parallel to each other.
　２つの空隙２７３の各々は、１次導体１１０を電流が流れる方向(Ｙ軸方向)において、１対の磁性体部材２７０の一端から他端まで延在している。２つの空隙２７３の各々は、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材２７０が成す矩形形状の両側辺のＺ軸方向の中央部に位置している。１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材２７０が成す矩形形状の中心位置と、１次導体１１０の貫通孔１１０ｈの位置とは重なっている。 Each of the two air gaps 273 extends from one end of the pair of magnetic members 270 to the other end in the direction in which the current flows through the primary conductor 110 (Y-axis direction). Each of the two gaps 273 is located at the center in the Z-axis direction on both sides of the rectangular shape formed by the pair of magnetic members 270 when viewed from the direction (Y-axis direction) in which the current flowing through the primary conductor 110 flows. is doing. The center position of the rectangular shape formed by the pair of magnetic members 270 and the position of the through hole 110h of the primary conductor 110 overlap each other when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). .
　図１５は、比較例３に係る電流センサの外観を示す斜視図である。図１６は、図１５の電流センサを矢印ＸＶＩ方向から見た平面図である。図１７は、図１６の電流センサをＸＶＩＩ－ＸＶＩＩ線矢印方向から見た断面図である。 FIG. 15 is a perspective view showing an appearance of a current sensor according to Comparative Example 3. FIG. 16 is a plan view of the current sensor of FIG. 15 viewed from the direction of the arrow XVI. FIG. 17 is a cross-sectional view of the current sensor of FIG. 16 viewed from the direction of the arrow XVII-XVII.
　図１５～１７に示すように、比較例３に係る電流センサ３００は、１次導体１１０を電流が流れる方向(Ｙ軸方向)から見て、それぞれＵ字形状を有する１対の磁性体部材３７０を備える。具体的には、１対の磁性体部材３７０は、第１磁性体部材３７１および第２磁性体部材３７２から構成されている。１対の磁性体部材３７０は、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、互いの端部同士の間に空隙３７３が設けられた矩形形状を成し、１次導体１１０および２つの磁気センサの周りを囲んでいる。具体的には、１対の磁性体部材３７０は、第１回路基板１６０ａ、第２回路基板１６０ｂ、および、第１回路基板１６０ａと第２回路基板１６０ｂとに挟まれた部分の１次導体１１０に対して間隔を置いて周りを囲んでいる。 As shown in FIGS. 15 to 17, the current sensor 300 according to the third comparative example has a pair of magnetic members 370 each having a U shape when the primary conductor 110 is viewed from the direction in which the current flows (Y-axis direction). Is provided. Specifically, the pair of magnetic members 370 includes a first magnetic member 371 and a second magnetic member 372. The pair of magnetic members 370 has a rectangular shape in which a gap 373 is provided between the ends when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). Surrounding the conductor 110 and the two magnetic sensors. Specifically, the pair of magnetic members 370 includes a first circuit board 160a, a second circuit board 160b, and a portion of the primary conductor 110 sandwiched between the first circuit board 160a and the second circuit board 160b. Is surrounded by a space.
　第１磁性体部材３７１および第２磁性体部材３７２の各々は、第１板状部と、第１板状部にそれぞれ直交して互いに対向している、第２板状部および第３板状部とを有している。第１磁性体部材３７１および第２磁性体部材３７２の各々の第１板状部と１次導体１１０とは、互いに平行に位置している。 Each of the first magnetic member 371 and the second magnetic member 372 has a first plate-like portion and a second plate-like portion and a third plate-like shape that are orthogonal to the first plate-like portion and face each other. Part. The first plate-like portions of the first magnetic member 371 and the second magnetic member 372 and the primary conductor 110 are positioned in parallel to each other.
　２つの空隙３７３の各々は、１次導体１１０を電流が流れる方向(Ｙ軸方向)において、１対の磁性体部材３７０の一端から他端まで延在している。２つの空隙３７３の各々は、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材３７０が成す矩形形状の上辺および下辺の各々のＸ軸方向の中央部に位置している。１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材３７０が成す矩形形状の中心位置と、１次導体１１０の貫通孔１１０ｈの位置とは重なっている。 Each of the two gaps 373 extends from one end of the pair of magnetic members 370 to the other end in the direction in which the current flows through the primary conductor 110 (Y-axis direction). Each of the two air gaps 373 is the center in the X-axis direction of each of the upper and lower sides of the rectangular shape formed by the pair of magnetic members 370 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). Located in the department. The center position of the rectangular shape formed by the pair of magnetic members 370 and the position of the through hole 110h of the primary conductor 110 overlap with each other when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). .
　実施例２に係る電流センサ、比較例２に係る電流センサ、および、比較例３に係る電流センサの各々において、共通の条件について説明する。空隙１７３，２７３，３７３の大きさは、１ｍｍとした。空隙１７３，２７３，３７３の大きさとは、第１磁性体部材１７１，２７１，３７１と第２磁性体部材１７２，２７２，３７２との最短距離である。 Common conditions in each of the current sensor according to the second embodiment, the current sensor according to the second comparative example, and the current sensor according to the third comparative example will be described. The size of the gaps 173, 273, and 373 was 1 mm. The size of the gaps 173, 273, 373 is the shortest distance between the first magnetic members 171, 271, 371 and the second magnetic members 172, 272, 372.
　１対の磁性体部材１７０，２７０，３７０の外形は、長さの寸法が２５．０ｍｍ、幅の寸法が２３．０ｍｍ、高さの寸法が２０．０ｍｍとした。第１磁性体部材１７１，２７１，３７１および第２磁性体部材１７２，２７２，３７２の各々の板厚は、０．５ｍｍとした。第１磁性体部材１７１，２７１，３７１および第２磁性体部材１７２，２７２，３７２の各々の材質は、４２アロイ(４２Ｎｉ)を用いた。 The outer shape of the pair of magnetic members 170, 270, and 370 was 25.0 mm in length, 23.0 mm in width, and 20.0 mm in height. The plate thickness of each of the first magnetic members 171, 271 and 371 and the second magnetic members 172, 272 and 372 was 0.5 mm. The material of each of the first magnetic members 171, 271, 371 and the second magnetic members 172, 272, 372 was 42 alloy (42Ni).
　１次導体１１０の外形は、長さの寸法が８０．０ｍｍ、幅の寸法が１３．０ｍｍ、高さの寸法が１．５ｍｍとした。１次導体１１０の材質は、無酸素銅(Ｃ１０２０)とした。 The outer dimensions of the primary conductor 110 were 80.0 mm in length, 13.0 mm in width, and 1.5 mm in height. The material of the primary conductor 110 was oxygen-free copper (C1020).
　シミュレーション解析は、有限要素法を用いて、１対の磁性体部材１７０，２７０，３７０が一様に磁化した状態を仮定して行なった。図１８は、１対の磁気シールドが一様に磁化した状態を示す模式図である。図１８に示すように、１次導体１１０を紙面手前側から紙面奥側に向けて電流が流れることにより、１対の磁性体部材１７０，２７０，３７０は、１対の磁性体部材１７０，２７０，３７０が成す矩形形状を右回りに周回するように矢印２で示す方向に磁化する。 The simulation analysis was performed on the assumption that a pair of magnetic members 170, 270, and 370 were uniformly magnetized using the finite element method. FIG. 18 is a schematic diagram showing a state in which a pair of magnetic shields are uniformly magnetized. As shown in FIG. 18, when a current flows through the primary conductor 110 from the front side of the drawing to the back side of the drawing, the pair of magnetic members 170, 270, and 370 are paired with the pair of magnetic members 170, 270. , 370 is magnetized in the direction indicated by arrow 2 so as to circulate clockwise.
　図１９は、シミュレーション解析におけるＺ軸方向の基準線および中心点を示す図である。図１９に示すように、１次導体１１０の幅方向の中央部の直上または直下に位置する基準線１上における磁束密度分布をシミュレーション解析により算出した。１次導体１１０の厚さ方向の中心位置Ｏを、Ｚ軸方向の原点とした。 FIG. 19 is a diagram showing a reference line and a center point in the Z-axis direction in the simulation analysis. As shown in FIG. 19, the magnetic flux density distribution on the reference line 1 located immediately above or directly below the central portion in the width direction of the primary conductor 110 was calculated by simulation analysis. The center position O in the thickness direction of the primary conductor 110 was set as the origin in the Z-axis direction.
　図２０は、実施例２、比較例２および比較例３に係る電流センサにおいて、１次導体の幅方向の中央部の直上または直下に位置する基準線上における、１次導体の厚さ方向の中心位置からの距離と１次導体の幅方向(Ｘ軸方向)の磁束密度との関係を示すグラフである。 FIG. 20 shows the center of the primary conductor in the thickness direction on the reference line located immediately above or directly below the central portion in the width direction of the primary conductor in the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3. It is a graph which shows the relationship between the distance from a position, and the magnetic flux density of the width direction (X-axis direction) of a primary conductor.
　図２１は、実施例２、比較例２および比較例３に係る電流センサにおいて、１次導体の幅方向の中央部の直上または直下に位置する基準線上における、１次導体の厚さ方向の中心位置からの距離と１次導体の長さ方向(Ｙ軸方向)の磁束密度との関係を示すグラフである。 FIG. 21 shows the center in the thickness direction of the primary conductor on the reference line located immediately above or directly below the center portion in the width direction of the primary conductor in the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3. It is a graph which shows the relationship between the distance from a position, and the magnetic flux density of the length direction (Y-axis direction) of a primary conductor.
　図２２は、実施例２、比較例２および比較例３に係る電流センサにおいて、１次導体の幅方向の中央部の直上または直下に位置する基準線上における、１次導体の厚さ方向の中心位置からの距離と１次導体の厚さ方向(Ｚ軸方向)の磁束密度との関係を示すグラフである。 FIG. 22 shows the center in the thickness direction of the primary conductor on the reference line located immediately above or directly below the central portion in the width direction of the primary conductor in the current sensors according to Example 2, Comparative Example 2 and Comparative Example 3. It is a graph which shows the relationship between the distance from a position, and the magnetic flux density of the thickness direction (Z-axis direction) of a primary conductor.
　図２０～２２においては、縦軸に、規格化した磁束密度、横軸に、１次導体１１０の厚さ方向の中心位置ＯからのＺ軸方向の距離(ｍｍ)を示している。図２０～２２においては、実施例２に係る電流センサ１００のデータを実線で、比較例２に係る電流センサ２００のデータを点線で、比較例３に係る電流センサ３００のデータを１点鎖線で示している。図２０～２２の各々の図中に、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々のＡＭＲ素子の配置位置１２１を示している。 20 to 22, the vertical axis represents the normalized magnetic flux density, and the horizontal axis represents the distance (mm) in the Z-axis direction from the center position O in the thickness direction of the primary conductor 110. 20 to 22, the data of the current sensor 100 according to the second embodiment is indicated by a solid line, the data of the current sensor 200 according to the comparative example 2 is indicated by a dotted line, and the data of the current sensor 300 according to the comparative example 3 is indicated by a one-dot chain line. Show. In each of FIGS. 20 to 22, the arrangement positions 121 of the AMR elements of the first magnetic sensor 120a and the second magnetic sensor 120b are shown.
　図２０に示すように、比較例２に係る電流センサ２００および比較例３に係る電流センサ３００の各々は、ＡＭＲ素子の配置位置１２１において、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々の検出軸の方向(Ｘ軸方向)の規格化磁束密度Ｂｘが、絶対値にて０．３～０．５程度であった。 As illustrated in FIG. 20, each of the current sensor 200 according to the comparative example 2 and the current sensor 300 according to the comparative example 3 includes the first magnetic sensor 120 a and the second magnetic sensor 120 b at the arrangement position 121 of the AMR element. The normalized magnetic flux density Bx in the detection axis direction (X-axis direction) was about 0.3 to 0.5 in absolute value.
　実施例２に係る電流センサ１００は、ＡＭＲ素子の配置位置１２１において、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々の検出軸の方向(Ｘ軸方向)の規格化磁束密度Ｂｘが、０．１以下であり、比較例２に係る電流センサ２００および比較例３に係る電流センサ３００に比較して小さかった。 In the current sensor 100 according to the second embodiment, the normalized magnetic flux density Bx in the detection axis direction (X-axis direction) of each of the first magnetic sensor 120a and the second magnetic sensor 120b is 0 at the AMR element arrangement position 121. .1 or less, which is smaller than the current sensor 200 according to Comparative Example 2 and the current sensor 300 according to Comparative Example 3.
　図２１，２２に示すように、実施例２に係る電流センサ１００、比較例２に係る電流センサ２００および比較例３に係る電流センサ３００の各々は、ＡＭＲ素子の配置位置１２１において、Ｙ軸方向の規格化磁束密度ＢｙおよびＺ軸方向の規格化磁束密度Ｂｚの各々が、略０であり、差は認められなかった。 As shown in FIGS. 21 and 22, each of the current sensor 100 according to the second embodiment, the current sensor 200 according to the second comparative example, and the current sensor 300 according to the third comparative example is arranged in the Y-axis direction at the arrangement position 121 of the AMR element. Each of the normalized magnetic flux density By and the normalized magnetic flux density Bz in the Z-axis direction was substantially 0, and no difference was recognized.
　このシミュレーション解析結果から、１対の磁性体部材の残留磁化により発生する磁界による測定誤差を低減するためには、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々の検出軸の方向(Ｘ軸方向)の規格化磁束密度Ｂｘが小さい、実施例２に係る電流センサ１００が、優れていることが確認された。 From this simulation analysis result, in order to reduce the measurement error due to the magnetic field generated by the remanent magnetization of the pair of magnetic members, the directions of the detection axes of the first magnetic sensor 120a and the second magnetic sensor 120b (X-axis) It was confirmed that the current sensor 100 according to Example 2 having a small (direction) normalized magnetic flux density Bx was excellent.
　次に、実施例２に係る電流センサ１００、比較例２に係る電流センサ２００および比較例３に係る電流センサ３００の各々において、１次導体１１０を流れる入力電流値と、図６に示すＯｕｔｐｕｔ部から出力されるセンサ出力電圧との関係を実測した結果について説明する。 Next, in each of the current sensor 100 according to the second embodiment, the current sensor 200 according to the second comparative example, and the current sensor 300 according to the third comparative example, an input current value flowing through the primary conductor 110 and the output unit illustrated in FIG. The result of actual measurement of the relationship with the sensor output voltage output from will be described.
　図２３は、実施例２に係る電流センサにおける入力電流値とセンサ出力電圧との関係を示すグラフである。図２４は、図２３における入力電流値の０Ａ近傍部３を拡大して示すグラフである。図２５は、比較例２に係る電流センサにおける入力電流値とセンサ出力電圧との関係を示すグラフである。図２６は、図２５における入力電流値の０Ａ近傍部３を拡大して示すグラフである。図２７は、比較例３に係る電流センサにおける入力電流値とセンサ出力電圧との関係を示すグラフである。図２８は、図２７における入力電流値の０Ａ近傍部３を拡大して示すグラフである。図２３～２８においては、縦軸にセンサ出力電圧(Ｖ)、横軸に入力電流(Ａ)を示している。 FIG. 23 is a graph showing a relationship between an input current value and a sensor output voltage in the current sensor according to the second embodiment. FIG. 24 is a graph showing an enlarged view of the vicinity 3 of the input current value in FIG. FIG. 25 is a graph showing the relationship between the input current value and the sensor output voltage in the current sensor according to Comparative Example 2. FIG. 26 is an enlarged graph showing the vicinity 3 of the input current value 0A in FIG. FIG. 27 is a graph showing the relationship between the input current value and the sensor output voltage in the current sensor according to Comparative Example 3. FIG. 28 is an enlarged graph showing the vicinity 3 of the input current value 0A in FIG. 23 to 28, the vertical axis represents the sensor output voltage (V), and the horizontal axis represents the input current (A).
　図２３～２８に示すように、１次導体１１０を流れる入力電流を正負で掃引した際に、比較例２に係る電流センサ２００および比較例３に係る電流センサ３００の各々においては、入力電流値の０Ａ近傍部３にてセンサ出力電圧に大きなずれが発生した。実施例２に係る電流センサ１００においては、１次導体１１０を流れる入力電流を正負で掃引した際に、入力電流値の０Ａ近傍部３にてセンサ出力電圧のずれは認められなかった。 As shown in FIGS. 23 to 28, when the input current flowing through the primary conductor 110 is swept positively and negatively, the current sensor 200 according to Comparative Example 2 and the current sensor 300 according to Comparative Example 3 each have an input current value. The sensor output voltage greatly deviated in the vicinity 3 of 0A. In the current sensor 100 according to Example 2, when the input current flowing through the primary conductor 110 was swept positively and negatively, no deviation in sensor output voltage was observed in the vicinity 3 of the input current value of 0A.
　図２９は、実施例２に係る電流センサ１００、比較例２に係る電流センサ２００、比較例３に係る電流センサ３００、比較例４に係る電流センサの各々のヒステリシス率を示すグラフである。図２９においては、縦軸にヒステリシス率(％ＦＳ)、横軸にサンプル名を示している。 FIG. 29 is a graph showing hysteresis rates of the current sensor 100 according to the second embodiment, the current sensor 200 according to the second comparative example, the current sensor 300 according to the third comparative example, and the current sensor according to the fourth comparative example. In FIG. 29, the vertical axis represents the hysteresis rate (% FS) and the horizontal axis represents the sample name.
　比較例４に係る電流センサは、１対の磁性体部材が設けられていない点のみ実施例１に係る電流センサと異なる。ヒステリシス率とは、入力電流値が０Ａである時のセンサ出力電圧の差の、入力電流値が±３００Ａである時のセンサ出力電圧に対する１００分率である。 The current sensor according to Comparative Example 4 differs from the current sensor according to Example 1 only in that a pair of magnetic members is not provided. The hysteresis rate is a 100-minute ratio of the difference in sensor output voltage when the input current value is 0 A to the sensor output voltage when the input current value is ± 300 A.
　図２９に示すように、比較例２に係る電流センサ２００および比較例３に係る電流センサ３００の各々においては、１．８％以上のヒステリシス率を有するのに対して、実施例２に係る電流センサ１００においては、ヒステリシス率が０．２％に低減され、１対の磁性体部材が設けられていない比較例４に係る電流センサのヒステリシス率である０．１％と略同等であった。 As shown in FIG. 29, each of the current sensor 200 according to the comparative example 2 and the current sensor 300 according to the comparative example 3 has a hysteresis rate of 1.8% or more, whereas the current according to the second example. In the sensor 100, the hysteresis rate was reduced to 0.2%, which was substantially the same as the hysteresis rate of 0.1% of the current sensor according to Comparative Example 4 in which the pair of magnetic members were not provided.
　この実測結果から、実施例２に係る電流センサ１００においては、１対の磁性体部材１７０を設けることによるヒステリシスの増加を抑制できることが確認できた。 From the actual measurement results, it was confirmed that in the current sensor 100 according to Example 2, an increase in hysteresis due to the provision of the pair of magnetic members 170 can be suppressed.
　上記の検証結果からも確認された通り、本実施形態に係る電流センサ１００においては、２つの空隙１７３の各々が、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材１７０が成す矩形形状の対角に位置していることにより、１対の磁性体部材１７０の残留磁化により発生する磁界による測定誤差を低減することができる。 As confirmed from the above verification results, in the current sensor 100 according to the present embodiment, each of the two air gaps 173 is 1 as viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). By being positioned at the diagonal of the rectangular shape formed by the pair of magnetic members 170, measurement errors due to the magnetic field generated by the residual magnetization of the pair of magnetic members 170 can be reduced.
　また、本実施形態に係る電流センサ１００においては、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々をロバスト領域内に位置させることにより、電流センサ１００の組み立てに高い精度が要求されないため、電流センサ１００を容易に製造可能である。 Further, in the current sensor 100 according to the present embodiment, since the first magnetic sensor 120a and the second magnetic sensor 120b are positioned in the robust region, high accuracy is not required for the assembly of the current sensor 100. The sensor 100 can be easily manufactured.
　以下、本発明の実施形態２に係る電流センサについて説明する。なお、実施形態２に係る電流センサ４００は、他の１対の磁性体部材をさらに備える点のみ実施形態１に係る電流センサと異なるため、他の構成については説明を繰り返さない。 Hereinafter, a current sensor according to Embodiment 2 of the present invention will be described. Note that the current sensor 400 according to the second embodiment is different from the current sensor according to the first embodiment only in that it further includes another pair of magnetic members, and thus the description of the other configurations will not be repeated.
　(実施形態２)
　図３０は、本発明の実施形態２に係る電流センサの構成を示す断面図である。図３０においては、図３と同様の方向から電流センサを見た断面視にて図示している。 (Embodiment 2)
FIG. 30 is a cross-sectional view showing a configuration of a current sensor according to Embodiment 2 of the present invention. 30 is a cross-sectional view of the current sensor as viewed from the same direction as in FIG.
　図３０に示すように、本発明の実施形態２に係る電流センサ４００は、１次導体１１０を電流が流れる方向(Ｙ軸方向)から見て、それぞれＬ字形状を有する他の１対の磁性体部材４７０をさらに備える。具体的には、他の１対の磁性体部材４７０は、第３磁性体部材４７１および第４磁性体部材４７２から構成されている。他の１対の磁性体部材４７０は、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、互いの端部同士の間に空隙４７３が設けられた矩形形状を成し、１対の磁性体部材１７０に対して間隔を置いて１対の磁性体部材１７０の周りを囲んでいる。他の１対の磁性体部材４７０の空隙４７３は、１対の磁性体部材１７０の各々の角部１７１ｒ，１７２ｒの外側に位置している。 As shown in FIG. 30, the current sensor 400 according to the second embodiment of the present invention includes another pair of magnetic elements each having an L shape when the primary conductor 110 is viewed from the direction in which the current flows (Y-axis direction). A body member 470 is further provided. Specifically, the other pair of magnetic members 470 is composed of a third magnetic member 471 and a fourth magnetic member 472. The other pair of magnetic members 470 has a rectangular shape in which a gap 473 is provided between the ends when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction), The pair of magnetic members 170 is surrounded by a distance from the pair of magnetic members 170. The gaps 473 of the other pair of magnetic members 470 are located outside the corners 171r and 172r of the pair of magnetic members 170, respectively.
　第３磁性体部材４７１および第４磁性体部材４７２の各々は、第３板状部と、第３板状部に直交している第４板状部とを有している。第３磁性体部材４７１および第４磁性体部材４７２の各々の第３板状部と１次導体１１０とは、互いに平行に位置している。第３磁性体部材４７１の第３板状部と、第２磁性体部材１７２の第１板状部とは、互いに間隔を置いて平行に位置している。第４磁性体部材４７２の第３板状部と、第１磁性体部材１７１の各々の第１板状部とは、互いに間隔を置いて平行に位置している。 Each of the third magnetic member 471 and the fourth magnetic member 472 has a third plate-like portion and a fourth plate-like portion orthogonal to the third plate-like portion. The third plate-like portion of each of the third magnetic member 471 and the fourth magnetic member 472 and the primary conductor 110 are positioned in parallel to each other. The third plate-like portion of the third magnetic member 471 and the first plate-like portion of the second magnetic member 172 are located in parallel with a distance from each other. The third plate-like portion of the fourth magnetic body member 472 and each first plate-like portion of the first magnetic body member 171 are positioned in parallel with an interval therebetween.
　第３磁性体部材４７１の第４板状部と、第１磁性体部材１７１の第２板状部とは、互いに間隔を置いて平行に位置している。第４磁性体部材４７２の第４板状部と、第２磁性体部材１７２の各々の第２板状部とは、互いに間隔を置いて平行に位置している。 The fourth plate-like portion of the third magnetic member 471 and the second plate-like portion of the first magnetic member 171 are located in parallel with a distance from each other. The fourth plate-like portion of the fourth magnetic body member 472 and each second plate-like portion of the second magnetic body member 172 are positioned in parallel with a space between each other.
　２つの空隙４７３の各々は、１次導体１１０を電流が流れる方向(Ｙ軸方向)において、他の１対の磁性体部材４７０の一端から他端まで延在している。２つの空隙４７３の各々は、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、他の１対の磁性体部材４７０が成す矩形形状の対角に位置している。１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、他の１対の磁性体部材４７０が成す矩形形状の中心位置と、１次導体１１０の貫通孔１１０ｈの位置とは重なっている。 Each of the two gaps 473 extends from one end of the other pair of magnetic members 470 to the other end in the direction in which the current flows through the primary conductor 110 (Y-axis direction). Each of the two gaps 473 is located at a diagonal of a rectangular shape formed by the other pair of magnetic members 470 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). When viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction), the center position of the rectangular shape formed by the other pair of magnetic members 470 overlaps the position of the through hole 110h of the primary conductor 110. ing.
　第３磁性体部材４７１および第４磁性体部材４７２の各々は、パーマロイで構成されているが、第３磁性体部材４７１および第４磁性体部材４７２の各々の材料は、パーマロイに限られず、軟鉄鋼、ケイ素鋼、電磁鋼、ニッケル合金、鉄合金またはフェライトなどの、透磁率および飽和磁束密度の高い磁性体材料であればよい。 Each of the third magnetic member 471 and the fourth magnetic member 472 is made of permalloy, but the material of each of the third magnetic member 471 and the fourth magnetic member 472 is not limited to permalloy, and is soft. Any magnetic material having high magnetic permeability and saturation magnetic flux density, such as iron steel, silicon steel, electromagnetic steel, nickel alloy, iron alloy, or ferrite, may be used.
　本実施形態においては、薄板をプレス加工することにより第３磁性体部材４７１および第４磁性体部材４７２の各々が形成されている。ただし、第３磁性体部材４７１および第４磁性体部材４７２の各々の形成方法はこれに限られず、切削または鋳造などの方法によって第３磁性体部材４７１および第４磁性体部材４７２の各々が形成されてもよい。 In the present embodiment, each of the third magnetic member 471 and the fourth magnetic member 472 is formed by pressing a thin plate. However, the formation method of each of the third magnetic member 471 and the fourth magnetic member 472 is not limited to this, and each of the third magnetic member 471 and the fourth magnetic member 472 is formed by a method such as cutting or casting. May be.
　図３０に示すように、本実施形態に係る電流センサ４００においては、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々は、１対の磁性体部材１７０および他の１対の磁性体部材４７０によって周りを２重に囲まれているため、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々に誤差要因である外部磁界が到達することをさらに抑制できる。その結果、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々が、不要な外部磁界を検知しないようにすることができる。すなわち、１対の磁性体部材１７０および他の１対の磁性体部材４７０の各々が、磁気シールドとして機能する。 As shown in FIG. 30, in the current sensor 400 according to the present embodiment, each of the first magnetic sensor 120a and the second magnetic sensor 120b includes a pair of magnetic members 170 and another pair of magnetic members 470. Therefore, it is possible to further suppress the external magnetic field, which is an error factor, from reaching each of the first magnetic sensor 120a and the second magnetic sensor 120b. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field. That is, each of the pair of magnetic members 170 and the other pair of magnetic members 470 functions as a magnetic shield.
　また、他の１対の磁性体部材４７０の空隙４７３が、１対の磁性体部材１７０の各々の角部１７１ｒ，１７２ｒの外側に位置していることにより、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの周りを、１対の磁性体部材１７０および他の１対の磁性体部材４７０によって完全に囲むことができる。その結果、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々が、不要な外部磁界をより検知しないようにすることができる。 Further, the gaps 473 of the other pair of magnetic members 470 are positioned outside the corners 171r and 172r of the pair of magnetic members 170, so that the first magnetic sensor 120a and the second magnetic member 120a. The sensor 120b can be completely surrounded by a pair of magnetic members 170 and another pair of magnetic members 470. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field.
　本実施形態に係る電流センサ４００においても、２つの空隙１７３の各々が、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材１７０が成す矩形形状の対角に位置していることにより、１対の磁性体部材１７０の残留磁化により発生する磁界による測定誤差を低減することができる。 Also in the current sensor 400 according to the present embodiment, each of the two gaps 173 has a rectangular shape formed by the pair of magnetic members 170 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). By being positioned diagonally, measurement errors due to the magnetic field generated by the residual magnetization of the pair of magnetic members 170 can be reduced.
　以下、本発明の実施形態３に係る電流センサについて説明する。なお、実施形態３に係る電流センサ５００は、１つのプリント基板に２つの磁気センサが実装されている点のみ実施形態２に係る電流センサと異なるため、他の構成については説明を繰り返さない。 Hereinafter, a current sensor according to Embodiment 3 of the present invention will be described. Note that the current sensor 500 according to the third embodiment is different from the current sensor according to the second embodiment only in that two magnetic sensors are mounted on one printed circuit board, and thus the description of the other configurations will not be repeated.
　(実施形態３)
　図３１は、本発明の実施形態３に係る電流センサの構成を示す断面図である。図３１においては、図３と同様の方向から電流センサを見た断面視にて図示している。図３１に示すように、本発明の実施形態３に係る電流センサ５００においては、プリント基板５３０ｃは、貫通孔５３０ｈに１次導体１１０を挿入された状態で保持される。すなわち、プリント基板５３０ｃは、１次導体１１０に垂直に位置している。 (Embodiment 3)
FIG. 31 is a cross-sectional view showing a configuration of a current sensor according to Embodiment 3 of the present invention. In FIG. 31, it shows in the cross-sectional view which looked at the current sensor from the same direction as FIG. As shown in FIG. 31, in the current sensor 500 according to Embodiment 3 of the present invention, the printed circuit board 530c is held in a state where the primary conductor 110 is inserted into the through hole 530h. That is, the printed circuit board 530 c is positioned perpendicular to the primary conductor 110.
　第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂは、差動増幅器および受動素子と共にプリント基板５３０ｃに実装されている。なお、図３１においては、差動増幅器および受動素子は図示していない。差動増幅器および受動素子は、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂが実装されているプリント基板５３０ｃとは異なるプリント基板に、実装されていてもよい。 The first magnetic sensor 120a and the second magnetic sensor 120b are mounted on a printed circuit board 530c together with a differential amplifier and a passive element. In FIG. 31, the differential amplifier and the passive element are not shown. The differential amplifier and the passive element may be mounted on a printed board different from the printed board 530c on which the first magnetic sensor 120a and the second magnetic sensor 120b are mounted.
　第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂは、貫通孔５３０ｈを挟んで互いに反対側に位置している。第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々は、貫通孔５３０ｈに対して間隔を置いて位置している。プリント基板５３０ｃの貫通孔５３０ｈに１次導体１１０が挿入された状態において、第１磁気センサ１２０ａは貫通孔５３０ｈの直上に位置し、第２プリント基板１３０ｂは貫通孔５３０ｈの直下に位置している。すなわち、第１磁気センサ１２０ａと第２磁気センサ１２０ｂとは、１次導体１１０を挟んで互いに反対側に位置している。 The first magnetic sensor 120a and the second magnetic sensor 120b are located on opposite sides of the through hole 530h. Each of the first magnetic sensor 120a and the second magnetic sensor 120b is located at an interval from the through hole 530h. In a state where the primary conductor 110 is inserted into the through hole 530h of the printed circuit board 530c, the first magnetic sensor 120a is positioned directly above the through hole 530h, and the second printed circuit board 130b is positioned directly below the through hole 530h. . That is, the first magnetic sensor 120a and the second magnetic sensor 120b are located on opposite sides of the primary conductor 110.
　本実施形態に係る電流センサ５００においては、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々は、ロバスト領域内に位置している。すなわち、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂがロバスト領域内に位置するように、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々と貫通孔５３０ｈとの間隔を適宜設定している。 In the current sensor 500 according to the present embodiment, each of the first magnetic sensor 120a and the second magnetic sensor 120b is located in the robust region. That is, the interval between each of the first magnetic sensor 120a and the second magnetic sensor 120b and the through hole 530h is appropriately set so that the first magnetic sensor 120a and the second magnetic sensor 120b are positioned in the robust region.
　第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々の検出軸の方向(感磁方向)は、１次導体１１０の幅方向(Ｘ軸方向)である。本実施形態に係る電流センサ５００においても、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々に作用するＸ軸方向、Ｙ軸方向およびＺ軸方向の磁束密度を低減することができるため、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂに加わる磁界の強度にばらつきが生ずることを抑制できる。その結果、電流センサ５００によって被測定電流の大きさを安定して測定することができる。 The direction (magnetic direction) of the detection axis of each of the first magnetic sensor 120a and the second magnetic sensor 120b is the width direction (X-axis direction) of the primary conductor 110. Also in the current sensor 500 according to the present embodiment, the magnetic flux density in the X-axis direction, the Y-axis direction, and the Z-axis direction acting on each of the first magnetic sensor 120a and the second magnetic sensor 120b can be reduced. Variations in the strength of the magnetic field applied to the first magnetic sensor 120a and the second magnetic sensor 120b can be suppressed. As a result, the current sensor 500 can stably measure the magnitude of the current to be measured.
　本実施形態に係る電流センサ５００においても、２つの空隙１７３の各々が、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材１７０が成す矩形形状の対角に位置していることにより、１対の磁性体部材１７０の残留磁化により発生する磁界による測定誤差を低減することができる。 Also in the current sensor 500 according to the present embodiment, each of the two gaps 173 has a rectangular shape formed by the pair of magnetic members 170 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). By being positioned diagonally, measurement errors due to the magnetic field generated by the residual magnetization of the pair of magnetic members 170 can be reduced.
　また、他の１対の磁性体部材４７０の空隙４７３が、１対の磁性体部材１７０の各々の角部１７１ｒ，１７２ｒの外側に位置していることにより、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの周りを、１対の磁性体部材１７０および他の１対の磁性体部材４７０によって完全に囲むことができる。その結果、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々が、不要な外部磁界をより検知しないようにすることができる。 Further, the gaps 473 of the other pair of magnetic members 470 are positioned outside the corners 171r and 172r of the pair of magnetic members 170, so that the first magnetic sensor 120a and the second magnetic member 120a. The sensor 120b can be completely surrounded by a pair of magnetic members 170 and another pair of magnetic members 470. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field.
　以下、本発明の実施形態４に係る電流センサについて説明する。なお、実施形態４に係る電流センサ６００は、プリント基板および磁性体部材が１次導体に対して付け外し可能に構成されている点のみ実施形態３に係る電流センサと異なるため、他の構成については説明を繰り返さない。 Hereinafter, a current sensor according to Embodiment 4 of the present invention will be described. The current sensor 600 according to the fourth embodiment differs from the current sensor according to the third embodiment only in that the printed circuit board and the magnetic member are configured to be detachable from the primary conductor. Will not repeat the description.
　(実施形態４)
　図３２は、本発明の実施形態４に係る電流センサにおいて、プリント基板および磁性体部材を１次導体に対して取り付けた状態を示す断面図である。図３３は、本発明の実施形態４に係る電流センサにおいて、プリント基板および磁性体部材を１次導体に対して取り付ける前の状態を示す断面図である。図３２，３３においては、図３と同様の方向から電流センサを見た断面視にて図示している。 (Embodiment 4)
FIG. 32 is a cross-sectional view showing a state where a printed circuit board and a magnetic member are attached to a primary conductor in a current sensor according to Embodiment 4 of the present invention. FIG. 33 is a cross-sectional view illustrating a state before the printed circuit board and the magnetic member are attached to the primary conductor in the current sensor according to the fourth embodiment of the present invention. 32 and 33 are shown in a cross-sectional view of the current sensor as viewed from the same direction as in FIG.
　図３１，３２に示すように、本発明の実施形態４に係る電流センサ６００においては、１対の磁性体部材１７０のうちの第１磁性体部材１７１、他の１対の磁性体部材４７０のうちの第３磁性体部材４７１、および、プリント基板６３０ｃが、樹脂または接着剤などからなる第１接合部材６８１により互いに接合されて一体になっている。１対の磁性体部材１７０のうちの第２磁性体部材１７２、および、他の１対の磁性体部材４７０のうちの第４磁性体部材４７２が、樹脂または接着剤などからなる第２接合部材６８２により互いに接合されて一体になっている。 As shown in FIGS. 31 and 32, in the current sensor 600 according to the fourth embodiment of the present invention, the first magnetic member 171 of the pair of magnetic members 170 and the other pair of magnetic members 470. The third magnetic body member 471 and the printed board 630c are joined together by a first joining member 681 made of resin or adhesive, and are integrated. The second magnetic member 172 of the pair of magnetic members 170 and the fourth magnetic member 472 of the other pair of magnetic members 470 are made of a resin or an adhesive. They are joined together by 682 and integrated.
　具体的には、プリント基板６３０ｃの周面と第１磁性体部材１７１の内面とが、第１接合部材６８１により互いに接合されている。互いに対向している、第１磁性体部材１７１の第２板状部の外面と第３磁性体部材４７１の第４板状部の内面とが、第１接合部材６８１により互いに接合されている。互いに対向している、第２磁性体部材１７２の第２板状部の外面と第４磁性体部材４７２の第４板状部の内面とが、第２接合部材６８２により互いに接合されている。第１接合部材６８１および第２接合部材６８２の各々が樹脂で構成されている場合には、熱溶着により上記の部材同士が接合される。 Specifically, the peripheral surface of the printed circuit board 630c and the inner surface of the first magnetic member 171 are joined to each other by the first joining member 681. The outer surface of the second plate-like portion of the first magnetic member 171 and the inner surface of the fourth plate-like portion of the third magnetic member 471 facing each other are joined to each other by the first joining member 681. The outer surface of the second plate-like portion of the second magnetic member 172 and the inner surface of the fourth plate-like portion of the fourth magnetic member 472 facing each other are joined to each other by the second joining member 682. When each of the 1st joining member 681 and the 2nd joining member 682 is comprised with resin, said members are joined by heat welding.
　プリント基板６３０ｃの周面のうち、第１磁性体部材１７１および第３磁性体部材４７１に囲まれていな端面側から、反対側の端面に向けて貫通溝６３０ｈが設けられている。プリント基板６３０ｃと第３磁性体部材４７１の第３板状部との間には、第２磁性体部材１７２の第１板状部が挿入可能な隙間が設けられている。 A through groove 630h is provided from the end surface side of the peripheral surface of the printed circuit board 630c that is not surrounded by the first magnetic member 171 and the third magnetic member 471 to the opposite end surface. A gap is provided between the printed board 630c and the third plate-like portion of the third magnetic member 471 so that the first plate-like portion of the second magnetic member 172 can be inserted.
　プリント基板６３０ｃ、１対の磁性体部材１７０および他の１対の磁性体部材４７０を１次導体１１０に対して取り付ける際には、プリント基板６３０ｃの貫通溝６３０ｈに１次導体１１０が挿入されるように、矢印６１で示す方向にプリント基板６３０ｃ、第１磁性体部材１７１および第３磁性体部材４７１を１次導体１１０に対して接近させる。また、プリント基板６３０ｃと第３磁性体部材４７１の第３板状部との間の隙間に第２磁性体部材１７２の第１板状部が挿入されるように、矢印６２で示す方向に第２磁性体部材１７２および第４磁性体部材４７２を１次導体１１０に対して接近させる。 When the printed board 630c, the pair of magnetic members 170, and the other pair of magnetic members 470 are attached to the primary conductor 110, the primary conductor 110 is inserted into the through groove 630h of the printed board 630c. As described above, the printed circuit board 630 c, the first magnetic member 171, and the third magnetic member 471 are moved closer to the primary conductor 110 in the direction indicated by the arrow 61. Further, the first plate-like portion of the second magnetic member 172 is inserted in the direction indicated by the arrow 62 so that the first plate-like portion of the second magnetic member 172 is inserted into the gap between the printed circuit board 630c and the third plate-like portion of the third magnetic member 471. The second magnetic member 172 and the fourth magnetic member 472 are brought closer to the primary conductor 110.
　図３２に示すように、プリント基板６３０ｃおよび磁性体部材を１次導体１１０に対して取り付けた状態においては、プリント基板６３０ｃは、貫通溝６３０ｈに１次導体１１０を挿入された状態で保持される。すなわち、プリント基板６３０ｃは、１次導体１１０に垂直に位置している。 As shown in FIG. 32, when the printed circuit board 630c and the magnetic member are attached to the primary conductor 110, the printed circuit board 630c is held with the primary conductor 110 inserted in the through groove 630h. . That is, the printed circuit board 630 c is positioned perpendicular to the primary conductor 110.
　本実施形態においては、２つの空隙１７３および２つの空隙４７３の各々は、第１接合部材６８１および第２接合部材６８２の少なくとも一方によって埋められている。本実施形態に係る電流センサ６００においては、プリント基板６３０ｃおよび磁性体部材が１次導体１１０に対して付け外し可能に構成されているため、電流センサ６００の組み立ておよび分解が容易である。 In the present embodiment, each of the two gaps 173 and the two gaps 473 is filled with at least one of the first joining member 681 and the second joining member 682. In the current sensor 600 according to the present embodiment, the printed circuit board 630c and the magnetic member are configured to be detachable from the primary conductor 110, so that the assembly and disassembly of the current sensor 600 is easy.
　本実施形態に係る電流センサ６００においても、２つの空隙１７３の各々が、１次導体１１０を流れる電流が流れる方向(Ｙ軸方向)から見て、１対の磁性体部材１７０が成す矩形形状の対角に位置していることにより、１対の磁性体部材１７０の残留磁化により発生する磁界による測定誤差を低減することができる。 Also in the current sensor 600 according to the present embodiment, each of the two gaps 173 has a rectangular shape formed by a pair of magnetic members 170 when viewed from the direction in which the current flowing through the primary conductor 110 flows (Y-axis direction). By being positioned diagonally, measurement errors due to a magnetic field generated by the residual magnetization of the pair of magnetic members 170 can be reduced.
　また、他の１対の磁性体部材４７０の空隙４７３が、１対の磁性体部材１７０の各々の角部１７１ｒ，１７２ｒの外側に位置していることにより、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの周りを、１対の磁性体部材１７０および他の１対の磁性体部材４７０によって完全に囲むことができる。その結果、第１磁気センサ１２０ａおよび第２磁気センサ１２０ｂの各々が、不要な外部磁界をより検知しないようにすることができる。 Further, the gaps 473 of the other pair of magnetic members 470 are positioned outside the corners 171r and 172r of the pair of magnetic members 170, so that the first magnetic sensor 120a and the second magnetic member 120a. The sensor 120b can be completely surrounded by a pair of magnetic members 170 and another pair of magnetic members 470. As a result, each of the first magnetic sensor 120a and the second magnetic sensor 120b can be prevented from detecting an unnecessary external magnetic field.
　今回開示された実施形態および実施例はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiments and examples disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
　１　基準線、３　近傍部、１０　電流、１００，２００，３００，４００，５００，６００　電流センサ、１１０　１次導体、１１０ｅ　磁界、１１０ｈ，５３０ｈ　貫通孔、１１０ｓ　表面、１１０ｔ　裏面、１２０ａ　第１磁気センサ、１２０ｂ　第２磁気センサ、１２１　配置位置、１３０ａ　第１プリント基板、１３０ｂ　第２プリント基板、１４０ａ　第１オペアンプ、１４０ｂ　第２オペアンプ、１５０ａ　第１受動素子、１５０ｂ　第２受動素子、１６０ａ　第１回路基板、１６０ｂ　第２回路基板、１７０，２７０，３７０，４７０　１対の磁性体部材、１７１，２７１，３７１　第１磁性体部材、１７２，２７２，３７２　第２磁性体部材、１７１ｒ，１７２ｒ　角部、１７３，２７３，３７３，４７３　空隙、１９０　算出部、４７１　第３磁性体部材、４７２　第４磁性体部材、５３０ｃ，６３０ｃ　プリント基板、６３０ｈ　貫通溝、６８１　第１接合部材、６８２　第２接合部材、Ｂｘ，Ｂｙ，Ｂｚ　規格化磁束密度、ＬＸ，ＬＺ，ＲＸ，ＲＺ　磁束密度、Ｏ　中心位置、Ｔ1　第１領域、Ｔ2　第２領域。 1 reference line, 3 neighbors, 10 current, 100, 200, 300, 400, 500, 600 current sensor, 110 primary conductor, 110e magnetic field, 110h, 530h through hole, 110s surface, 110t back surface, 120a first magnetic sensor , 120b second magnetic sensor, 121 arrangement position, 130a first printed circuit board, 130b second printed circuit board, 140a first operational amplifier, 140b second operational amplifier, 150a first passive element, 150b second passive element, 160a first circuit board , 160b Second circuit board, 170, 270, 370, 470 One pair of magnetic members, 171, 271, 371 First magnetic member, 172, 272, 372 Second magnetic member, 171r, 172r Corner, 173 , 273, 373, 473 gap, 190 calculation unit, 471 third magnetic body member, 47 Fourth magnetic member, 530c, 630c Printed circuit board, 630h Through groove, 681 First joint member, 682 Second joint member, Bx, By, Bz Normalized magnetic flux density, LX, LZ, RX, RZ magnetic flux density, O center Position, T 1 first region, T 2 second region.

Claims (7)

  1. 　測定対象の電流が流れる１次導体と、
    　前記１次導体を流れる前記電流により発生する磁界の強さを検出する少なくとも１つの磁気センサと、
    　前記電流が流れる方向から見て、それぞれＬ字形状を有する１対の磁性体部材とを備え、
    　前記１対の磁性体部材は、前記電流が流れる方向から見て、互いの端部同士の間に空隙が設けられた矩形形状を成し、前記１次導体および前記磁気センサの周りを囲んでいる、電流センサ。     A primary conductor through which the current to be measured flows;
    At least one magnetic sensor for detecting the strength of a magnetic field generated by the current flowing through the primary conductor;
    A pair of magnetic members each having an L shape when viewed from the direction in which the current flows,
    The pair of magnetic members has a rectangular shape with a gap provided between the ends when viewed from the direction in which the current flows, and surrounds the primary conductor and the magnetic sensor. A current sensor.
  2. 　前記１次導体は、平板形状を有し、
    　前記磁気センサは、前記１次導体の厚さ方向および前記電流が流れる方向の両方と直交する方向の磁界を検出可能とされている、請求項１に記載の電流センサ。     The primary conductor has a flat plate shape,
    The current sensor according to claim 1, wherein the magnetic sensor is capable of detecting a magnetic field in a direction orthogonal to both a thickness direction of the primary conductor and a direction in which the current flows.
  3. 　前記磁気センサは、前記１次導体の幅方向における中央部の、前記１次導体の厚さ方向における一方側および他方側の少なくとも一方に配置されている、請求項１または２に記載の電流センサ。 3. The current sensor according to claim 1, wherein the magnetic sensor is disposed on at least one of one side and the other side in the thickness direction of the primary conductor at a central portion in the width direction of the primary conductor. .
  4. 　前記磁気センサとして第１磁気センサと第２磁気センサとを備え、
    　前記第１磁気センサと前記第２磁気センサとは、前記１次導体を挟んで互いに対向して位置している、請求項１から３のいずれか１項に記載の電流センサ。     A first magnetic sensor and a second magnetic sensor as the magnetic sensor;
    4. The current sensor according to claim 1, wherein the first magnetic sensor and the second magnetic sensor are positioned to face each other across the primary conductor. 5.
  5. 　前記第１磁気センサの検出値と前記第２磁気センサの検出値とを演算することにより前記電流の値を算出する算出部をさらに備え、
    　前記１次導体を流れる前記電流により発生する磁界の強さについて、前記第１磁気センサの検出値の位相と前記第２磁気センサの検出値の位相とが逆相であり、
    　前記算出部が減算器または差動増幅器である、請求項４に記載の電流センサ。     A calculation unit that calculates a value of the current by calculating a detection value of the first magnetic sensor and a 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 reverse phase,
    The current sensor according to claim 4, wherein the calculation unit is a subtractor or a differential amplifier.
  6. 　前記第１磁気センサの検出値と前記第２磁気センサの検出値とを演算することにより前記電流の値を算出する算出部をさらに備え、
    　前記１次導体を流れる前記電流により発生する磁界の強さについて、前記第１磁気センサの検出値の位相と前記第２磁気センサの検出値の位相とが同相であり、
    　前記算出部が加算器または加算増幅器である、請求項４に記載の電流センサ。     A calculation unit that calculates a value of the current by calculating a detection value of the first magnetic sensor and a 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 current sensor according to claim 4, wherein the calculation unit is an adder or an addition amplifier.
  7. 　前記電流が流れる方向から見て、それぞれＬ字形状を有する他の１対の磁性体部材とをさらに備え、
    　前記他の１対の磁性体部材は、前記電流が流れる方向から見て、互いの端部同士の間に空隙が設けられた矩形形状を成し、前記１対の磁性体部材に対して間隔を置いて前記１対の磁性体部材の周りを囲み、
    　前記他の１対の磁性体部材の空隙は、前記１対の磁性体部材の各々の角部の外側に位置している、請求項１から６のいずれか１項に記載の電流センサ。     Another pair of magnetic members each having an L-shape when viewed from the direction in which the current flows,
    The other pair of magnetic members has a rectangular shape in which a gap is provided between the ends when viewed from the direction in which the current flows, and is spaced from the pair of magnetic members. To surround the pair of magnetic members,
    The current sensor according to any one of claims 1 to 6, wherein the gap between the other pair of magnetic members is located outside a corner of each of the pair of magnetic members.
PCT/JP2015/073807 2014-09-05 2015-08-25 Current sensor WO2016035606A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2014-181245 2014-09-05
JP2014181245 2014-09-05
JP2014231694 2014-11-14
JP2014-231694 2014-11-14

Publications (1)

Publication Number Publication Date
WO2016035606A1 true WO2016035606A1 (en) 2016-03-10

Family

ID=55439672

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/073807 WO2016035606A1 (en) 2014-09-05 2015-08-25 Current sensor

Country Status (1)

Country Link
WO (1) WO2016035606A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109416377A (en) * 2016-07-15 2019-03-01 阿尔卑斯电气株式会社 Current sensor
EP3692379A4 (en) * 2017-10-02 2021-11-03 ABB Schweiz AG Flux absorber for power line device
US11555835B2 (en) * 2018-11-01 2023-01-17 Murata Manufacturing Co., Ltd. Current sensor

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001281270A (en) * 2000-03-31 2001-10-10 Sumitomo Special Metals Co Ltd Split type current detector
JP2007033303A (en) * 2005-07-28 2007-02-08 Mitsubishi Electric Corp Electric current detector
JP2012052980A (en) * 2010-09-03 2012-03-15 Alps Green Devices Co Ltd Current sensor
JP2013015371A (en) * 2011-07-01 2013-01-24 Toshiba Toko Meter Systems Co Ltd Current detector and watt-hour meter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001281270A (en) * 2000-03-31 2001-10-10 Sumitomo Special Metals Co Ltd Split type current detector
JP2007033303A (en) * 2005-07-28 2007-02-08 Mitsubishi Electric Corp Electric current detector
JP2012052980A (en) * 2010-09-03 2012-03-15 Alps Green Devices Co Ltd Current sensor
JP2013015371A (en) * 2011-07-01 2013-01-24 Toshiba Toko Meter Systems Co Ltd Current detector and watt-hour meter

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109416377A (en) * 2016-07-15 2019-03-01 阿尔卑斯电气株式会社 Current sensor
EP3692379A4 (en) * 2017-10-02 2021-11-03 ABB Schweiz AG Flux absorber for power line device
US11353480B2 (en) 2017-10-02 2022-06-07 Abb Schweiz Ag Flux absorber for power line device
US11555835B2 (en) * 2018-11-01 2023-01-17 Murata Manufacturing Co., Ltd. Current sensor

Similar Documents

Publication Publication Date Title
JP6265282B2 (en) Current sensor
US10605835B2 (en) Current sensor
JP5531215B2 (en) Current sensor
WO2016194633A1 (en) Electric current sensor
WO2018185964A1 (en) Current sensor
WO2015133621A1 (en) Amperage detector
JP6299069B2 (en) Magnetic sensor device
JP6540802B2 (en) Current sensor
WO2017018306A1 (en) Electric current sensor
JP6311790B2 (en) Current sensor
WO2017002678A1 (en) Current sensor
JP2013210335A (en) Magnetic sensor
JP2016148620A (en) Current sensor
WO2016035606A1 (en) Current sensor
JP2015036636A (en) Current sensor
JP6121311B2 (en) Magnetic detector
JP2013088370A (en) Current sensor
JP6361740B2 (en) Current sensor
JP2012215405A (en) Magnetic sensor device
WO2015174247A1 (en) Electric current sensor
JP6304380B2 (en) Current sensor
JP2013047610A (en) Magnetic balance type current sensor
JP2012159309A (en) Magnetic sensor and magnetic sensor apparatus
JP2017026573A (en) Current sensor
JP2015031647A (en) Current sensor and manufacturing method therefor

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15837640

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: JP

122 Ep: pct application non-entry in european phase

Ref document number: 15837640

Country of ref document: EP

Kind code of ref document: A1