WO2012060069A1 - Capteur de courant - Google Patents

Capteur de courant Download PDF

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Publication number
WO2012060069A1
WO2012060069A1 PCT/JP2011/005922 JP2011005922W WO2012060069A1 WO 2012060069 A1 WO2012060069 A1 WO 2012060069A1 JP 2011005922 W JP2011005922 W JP 2011005922W WO 2012060069 A1 WO2012060069 A1 WO 2012060069A1
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WO
WIPO (PCT)
Prior art keywords
magnetic
current
magnetic flux
detection element
flux collector
Prior art date
Application number
PCT/JP2011/005922
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English (en)
Japanese (ja)
Inventor
正憲 鮫島
伸夫 布施
卓哉 冨田
植松　秀典
原田　真二
澄夫 前川
和弘 尾中
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パナソニック株式会社
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Publication of WO2012060069A1 publication Critical patent/WO2012060069A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
    • G01R15/205—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 using magneto-resistance devices, e.g. field plates
    • 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
    • G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
    • G01R15/183—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using transformers with a magnetic core
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/0011—Arrangements or instruments for measuring magnetic variables comprising means, e.g. flux concentrators, flux guides, for guiding or concentrating the magnetic flux, e.g. to the magnetic sensor

Definitions

  • the present invention relates to a current sensor that detects a current to be measured by a magnetic field generated around a current line through which the current to be measured flows.
  • a current sensor has been required to detect battery current of hybrid cars, EV cars, etc., drive current of electric motors, and the like.
  • a cancel coil 3 is wound around a ring-type magnetic core 2 with a gap surrounding the current line 1 and a Hall element 4 is disposed in the gap portion. 1 was measured.
  • Patent Document 1 is known as prior art document information related to the invention of this application.
  • the current line 1 needs to be surrounded by the ring-type magnetic core 2 with a gap, and the shape becomes large.
  • the current line 1 through which a large current of about 200 A flows increases in cross-sectional area, and it is necessary to increase the ring-type magnetic core 2 in order to prevent magnetic saturation. While the shape of the current sensor is further increased, if it is attempted to detect this current, it is necessary to pass a large current through the cancel coil 3, resulting in a large power consumption.
  • the current sensor of the present invention is arranged on one surface of a current line, detects a magnetic field to be measured generated by a current flowing through the current line, and first and second magnetic sensors positioned substantially parallel to the magnetic field to be measured.
  • a fourth magnetic flux collecting portion that is sandwiched between the other ends of the first portion and positioned in a substantially orthogonal direction, the first magnetic flux collecting portion, the second magnetic flux collecting portion, the third magnetic flux collecting portion, and the fourth magnetic flux collecting portion.
  • a magnetic yoke including a connecting portion connecting the magnetic detecting element and the magnetic detecting element is disposed between the third magnetic collecting portion and the fourth magnetic collecting portion.
  • the current sensor of the present invention it is possible to use a magnetic detection element using an element having a high sensitivity but a narrow measurement range, such as an MR element. Can be realized.
  • FIG. 1 is a perspective view of a current sensor according to Embodiment 1 of the present invention.
  • FIG. 2 is a plan view of the current sensor according to Embodiment 1 of the present invention.
  • FIG. 3 is a plan view of the magnetic yoke according to the first embodiment of the present invention.
  • FIG. 4A is a plan view of the magnetic detection element according to Embodiment 1 of the present invention.
  • 4B is a cross-sectional view taken along line 4B-4B of FIG. 4A.
  • FIG. 5 is a cross-sectional view of a current sensor according to Embodiment 2 of the present invention.
  • FIG. 6 is a perspective view of a current sensor according to Embodiment 2 of the present invention.
  • FIG. 1 is a perspective view of a current sensor according to Embodiment 1 of the present invention.
  • FIG. 2 is a plan view of the current sensor according to Embodiment 1 of the present invention.
  • FIG. 3 is a plan view of the magnetic
  • FIG. 7 is a circuit diagram for explaining the operation of the current sensor according to the second embodiment of the present invention.
  • FIG. 8 is a perspective view of a current sensor according to Embodiment 3 of the present invention.
  • FIG. 9 is a cross-sectional view of a current sensor according to Embodiment 3 of the present invention.
  • FIG. 10 is a perspective view of the magnetic yoke of the current sensor according to Embodiment 3 of the present invention.
  • FIG. 11 is a diagram showing cancel coil current consumption of the magnetic yoke of the current sensor and the magnetic yoke of the comparative example according to the third embodiment of the present invention.
  • FIG. 12 is a cross-sectional view of another current sensor according to Embodiment 3 of the present invention.
  • FIG. 13 is a cross-sectional view of a current sensor according to Embodiment 4 of the present invention.
  • FIG. 14 is a perspective view of a current sensor according to Embodiment 4 of the present invention.
  • FIG. 15 is a cross-sectional view of a current sensor according to Embodiment 4 of the present invention.
  • FIG. 16 is a perspective view of a current sensor according to Embodiment 5 of the present invention.
  • FIG. 17 is a plan view of a current sensor according to Embodiment 5 of the present invention.
  • 18 is a cross-sectional view taken along line 18-18 of FIG. FIG.
  • FIG. 19 shows the current I flowing through the current line and the magnetic field when the current sensor having the integrated magnetic yoke and the current sensor according to the fifth embodiment of the present invention are arranged at a position 2 mm above the central axis of the current line. It is a figure which shows the shift
  • FIG. 20 is a perspective view of a current sensor according to Embodiment 6 of the present invention.
  • FIG. 21 is a perspective view of the core of the current sensor according to Embodiment 6 of the present invention.
  • FIG. 22 is a diagram showing cancel coil current consumption of the core of the current sensor and the core of the comparative example according to the sixth embodiment of the present invention.
  • FIG. 23A is a cross-sectional view showing the assembly process of the current sensor according to Embodiment 6 of the present invention.
  • FIG. 23B is a cross-sectional view showing the assembly process of the current sensor according to Embodiment 6 of the present invention.
  • FIG. 23C is a cross-sectional view showing a process for assembling the current sensor according to Embodiment 6 of the present invention.
  • FIG. 23D is a cross-sectional view showing the assembly process of the current sensor in the sixth embodiment of the present invention.
  • FIG. 24 is a perspective view of a current sensor according to Embodiment 7 of the present invention.
  • FIG. 25 is a cross-sectional view of a current sensor according to Embodiment 7 of the present invention.
  • FIG. 26 is a longitudinal sectional view of a current sensor according to Embodiment 7 of the present invention.
  • FIG. 27 is a diagram showing the relationship between the current flowing through the current line of the current sensor according to the seventh embodiment of the present invention, the cancellation current flowing through the first current detection element, and the cancellation current flowing through the second current detection element.
  • FIG. 28 is a circuit diagram for explaining the operation of the current sensor according to the seventh embodiment of the present invention.
  • FIG. 29 shows the current flowing in the current line when the threshold voltage is set so that the output of the comparator drops to low when the current flowing in the current line of the current sensor in the seventh embodiment of the present invention exceeds 50 A.
  • FIG. 30 is a cross-sectional view of another current sensor according to Embodiment 7 of the present invention.
  • FIG. 31 is a cross-sectional view of a current sensor according to Embodiment 7 of the present invention.
  • FIG. 32 is a perspective view of a current sensor according to Embodiment 8 of the present invention.
  • FIG. 33 is a cross-sectional view of a current sensor according to Embodiment 8 of the present invention.
  • FIG. 34 is a perspective view of a conventional current sensor.
  • FIG. 1 is a perspective view of a current sensor according to Embodiment 1 of the present invention
  • FIG. 2 is a plan view of the current sensor according to Embodiment 1 of the present invention
  • FIG. 3 is a plan view of a magnetic yoke according to Embodiment 1 of the present invention. It is.
  • a current sensor 12 having a magnetic yoke 15 and a magnetic detection element 13 is placed on a current line 11 through which a current I flows in the Y-axis direction. Is arranged.
  • the current line 11 is made of copper or the like having a rectangular cross section of 18 mm and 3 mm in the X-axis and Z-axis directions, respectively, and the lengths in the X-axis, Y-axis, and Z-axis directions are approximately on the XY plane. 8 mm, 8 mm, and 4 mm current sensors 12 are arranged.
  • the magnetic yoke 15 that is one of the components of the current sensor 12 is made of a magnetic material such as iron or an iron alloy. As shown in FIG. 3, the specific shape of the magnetic yoke 15 includes a first magnetism collecting portion 15a, a second magnetism collecting portion 15b, a third magnetism collecting portion 15c, a fourth magnetism collecting portion 15d, and a connection. Part 15e, 15f, 15g, 15h is provided. The components of these magnetic yokes 15 are located on the same plane. The first magnetism collecting portion 15a, the second magnetism collecting portion 15b, the third magnetism collecting portion 15c, and the fourth magnetism collecting portion 15d extend substantially in parallel.
  • the first magnetic flux collector 15a and the third magnetic flux collector 15c are connected by a connecting portion 15e
  • the first magnetic flux collector 15a and the fourth magnetic flux collector 15d are connected by a connecting portion 15f
  • 15b and the third magnetic flux collector 15c are connected by a connecting portion 15g
  • the second magnetic flux collector 15b and a fourth magnetic flux collector 15d are connected by a connecting portion 15h.
  • a gap 15j exists between the third magnetism collecting portion 15c and the fourth magnetism collecting portion 15d, and the magnetic detection element 3 is arranged in the gap 15j.
  • the third magnetism collecting portion 15c and the fourth magnetism collecting portion 15d have a gap 15j, and the magnetic detection element 13 is disposed between the gaps 15j.
  • the direction in which the first magnetic collecting portion 15a and the second magnetic collecting portion 15b extend that is, the horizontal direction in FIG. 3 is the direction perpendicular to the current I flowing through the current line 11, in other words, the current line 11 is It is arranged so as to be in the same direction as the magnetic field to be measured due to the current to be measured.
  • the second magnetic flux collector 15b, the third magnetic flux collector 15c, and the fourth magnetic flux collector 15d are connected to 15e, 15f, 15g, and 15h.
  • FIG. 4A is a plan view of the magnetic detection element according to Embodiment 1 of the present invention
  • FIG. 4B is a cross-sectional view taken along line 4B-4B of FIG. 4A.
  • the insulating substrate 21 is made of a plate-like ceramic.
  • four electrodes that is, an input electrode 22a, a first output electrode 22b, a second output electrode 22d, and a ground electrode 22c are formed.
  • a meandering magnetoresistive element 20a made of a magnetoresistor is formed between the input electrode 22a and the first output electrode 22b.
  • the magnetoresistive element 20b is provided between the first output electrode 22b and the ground electrode 22c, and the magnetoresistive element 20d, the second output electrode 22d and the ground are provided between the input electrode 22a and the second output electrode 22d.
  • a magnetoresistive element 20c is formed between the electrodes 22c.
  • the input electrode 22a, the first output electrode 22b, the second output electrode 22d, the ground electrode 22c, and the magnetoresistive elements 20a to 20d constitute a bridge circuit.
  • the magnetoresistive elements 20a to 20d are formed so as to have the same characteristics.
  • the magnetoresistive elements 20a to 20d are all made of a material having a magnetoresistive effect, specifically, a magnetoresistive thin film having a thickness of about 0.1 ⁇ m made of a ferromagnetic material such as Ni—Co, which is a so-called MR thin film.
  • the magnetoresistive elements 20a to 20d all have a meandering shape, but the longitudinal shape of the meandering pattern is formed in a direction perpendicular to the adjacent magnetoresistive elements. That is, in FIG.
  • the magnetoresistive element 20a has the longitudinal direction of the meandering pattern in a 45 ° direction inclined obliquely to the right on the paper surface, but the magnetoresistive element 20b adjacent thereto is located on the left side of the paper surface.
  • the longitudinal direction of the meander pattern is located in a 45 ° direction inclined obliquely upward, and the angle between them is a right angle.
  • the positional relationship between the magnetoresistive element 20c and the magnetoresistive element 20d is the same. Further, the positional relationship between the magnetoresistive element 20a and the magnetoresistive element 20c is the same.
  • the direction perpendicular to the longitudinal direction of the meander pattern is the magnetosensitive direction.
  • the insulating layer 23a is made of a SiO 2 thin film having a thickness of about 1 ⁇ m and covers the magnetoresistive elements 20a to 20d to electrically insulate a thin film magnet 24 described later.
  • the thin film magnet 24 is made of CoPt having a thickness of about 0.6 ⁇ m, and is formed on the insulating layer 23a by vapor deposition, sputtering, or the like, and then patterned by exposure and etching to have a plurality of substantially rectangular parallelepiped shapes having a longitudinal direction. It is a thin film magnet divided into two.
  • the direction of the magnetic field generated by the thin film magnet 24 is the right-angle direction of the longitudinal direction of the thin film magnet 24, that is, the left-right direction in FIG.
  • the thin film magnet 24 is divided into a plurality of substantially rectangular parallelepipeds having a longitudinal direction in a direction forming 45 ° with respect to the longitudinal direction of the pattern of the magnetoresistive elements 20a to 20d.
  • This direction is also a direction that forms 45 ° with respect to the magnetic sensing direction of the magnetoresistive elements 20a to 20d.
  • the magnetic field generated by the thin film magnet 24 is arranged in the same direction as the current flowing through the current line 11, in other words, the direction perpendicular to the magnetic field generated by the current to be measured flowing through the current line 11. Therefore, the direction of the magnetic field generated by the thin film magnet 24 is a direction perpendicular to the direction in which the third magnetic flux collecting portion 15c and the fourth magnetic flux collecting portion 15d of the magnetic yoke 15 extend.
  • the insulating layer 23 b is made of a SiO 2 thin film and covers the thin film magnet 24.
  • the insulating layer 23a and the insulating layer 23b are formed so that the input electrode 22a, the first output electrode 22b, the second output electrode 22d, and the ground electrode 22c are exposed. In FIG. 4A, the insulating layer 23b is omitted.
  • the magnetic detection element 13 includes the insulating substrate 21, the input electrode 22a, the first output electrode 22b, the second output electrode 22d, the ground electrode 22c, the magnetoresistive elements 20a to 20d, the insulating layer 23a, the thin film magnet 24, and the insulating layer. 23b.
  • a predetermined voltage is applied to the input electrode 22a so as to generate a constant potential difference with the ground electrode 22c.
  • the magnetoresistive element 20a and the magnetoresistive element 20c have the same magnetosensitive direction, the same resistance value change occurs even when the magnetic field changes.
  • the magnetoresistive element 20b and the magnetoresistive element 20d have the same magnetic sensing direction, they also cause the same change in resistance value even when the magnetic field changes. Accordingly, the change in the potential of the first output electrode 22b and the second output electrode 22d with respect to the change in the magnetic field is in the opposite direction, that is, when one increases by ⁇ V, the other decreases by ⁇ V.
  • the magnetic field in the magnetic detection element 13 is detected by detecting the operation output of the first output electrode 22b and the second output electrode 22d, and the current flowing through the current line 11 is thereby measured. Is the basic detection principle.
  • a magnetic field H I due to the current I is generated and applied to the magnetic detection element 13.
  • a magnetic field obtained by combining the bias magnetic field H B and the magnetic field H I due to the current I is applied to the magnetoresistive elements 20a to 20d.
  • the resistance values of the magnetoresistive element 20a and the magnetoresistive element 20b are different, and the resistance values of the magnetoresistive element 20c and the magnetoresistive element 20d are also different.
  • a first output electrode 22b and the second output electrode 22 d the change in potential due to the magnetic field is in the opposite direction, and detects the magnetic field H I a differential output of the two electrodes, this by the current I Can be measured.
  • the magnetic yoke 15 is configured as shown in FIGS.
  • the third magnetic flux collecting portion 15c and the fourth magnetic flux collecting portion 15d are provided with a gap 15j, so that the magnetic resistance is high.
  • no gap is formed in the first magnetism collecting portion 15a and the second magnetism collecting portion 15b, and the magnetic resistance is low. Therefore, the magnetic flux passing through the magnetic yoke 15 is more likely to pass through the first magnetic collecting portion 15a and the second magnetic collecting portion 15b than the third magnetic collecting portion 15c and the fourth magnetic collecting portion 15d.
  • the magnetic detection element 13 is arrange
  • FIG. Therefore, the magnetic detection element 13 is passed by adjusting the magnetic resistances of the first magnetic collecting part 15a, the second magnetic collecting part 15b, the third magnetic collecting part 15c, and the fourth magnetic collecting part 15d. Magnetic flux can be reduced.
  • the magnetic field is about 4 mT depending on conditions such as the shape of the current line 11 and the position from the conductor.
  • the MR thin film should be used up to about 10 mT from the point of saturation magnetic field, but the region where the rate of change in resistance to the magnetic field is linear is narrower. Actually, it is preferably used in the range of 1 to 2 mT.
  • the magnetosensitive directions of the magnetoresistive elements 20a to 20d are inclined by 45 ° with respect to the magnetic field generated by the current line 11, and the magnetic field applied to the MR thin film is 1 / 1.4 times to 1 / 2.8. Need to double. That is, the reduction rate of the magnetic flux passing through the third magnetic collecting portion 15c and the fourth magnetic collecting portion 15d may be set to about 1 / 1.4 times to 1 / 2.8 times.
  • the magnetosensitive direction of the MR thin film has anisotropy, it is impossible to discriminate a magnetic field in the reverse direction of 180 °. Therefore, if a current of 200 A flows through the current line 11 in the reverse direction, the above 1 / 2 times reduction rate, that is, 1 / 2.8 times to 1 / 5.6 times.
  • the magnetic field passing through the magnetoresistive elements 20a to 20d is a combined magnetic field of the bias magnetic field from the thin film magnet 24 and the magnetic field from the current line 11, it is actually set in consideration of the bias magnetic field from the thin film magnet 24. do it.
  • the rate of reduction that makes the magnetic flux passing through the third magnetic collecting portion 15c and the fourth magnetic collecting portion 15d about 1 / 2.8 is that of the first magnetic collecting portion 15a and the second magnetic collecting portion 15b. It can be changed by setting the magnetic resistance and the magnetic resistance of the third magnetic collecting portion 15c and the fourth magnetic collecting portion 15d. As an example, there is a method in which the width is determined by the widths of the first and second magnetic flux collecting portions 15a and 15b, the third magnetic flux collecting portion 15c and the fourth magnetic flux collecting portion 15d, and the length of the gap 15j. is there.
  • the current sensor 12 can use the magnetic detection element 13 using an element having a high sensitivity such as an MR element but a narrow measurement range.
  • the surrounding core is unnecessary, and downsizing can be realized.
  • FIG. 5 is a cross-sectional view of a current sensor according to Embodiment 2 of the present invention.
  • FIG. 5 shows a view when the current sensor 50 is installed on the current line 11 through which the current I flows, and is viewed from above when the current sensor 50 is cut horizontally.
  • FIG. 6 is a perspective view of a current sensor according to Embodiment 2 of the present invention.
  • the current sensor 50 includes a magnetic detection element 13, a cancel coil 14 that surrounds the periphery of the magnetic detection element 13, and a magnetic yoke 15.
  • the current sensor 50 has lengths in the X-axis, Y-axis, and Z-axis directions of approximately 8 mm, 8 mm, and 4 mm, respectively.
  • the configurations of the magnetic detection element 13 and the magnetic yoke 15 are the same as those in the first embodiment, and thus description thereof is omitted.
  • the cancel coil 14 is formed by winding a copper wire having an insulating coating on its surface, and surrounds the magnetic detection element 13 so that its winding axis is perpendicular to the current I (that is, the same direction as the magnetic field induced by the current I). It is provided to become.
  • the current flowing through the current line 11 is detected by canceling out the measured magnetic field in the magnetic detection element 13 by the magnetic field generated by flowing the compensation current through the cancel coil 14.
  • FIG. 7 is a circuit diagram for explaining the operation of the current sensor 50 according to the second embodiment of the present invention.
  • a power supply 26 that applies a constant voltage is connected between the input electrode 22 a and the ground electrode 22 c of the magnetic detection element 13.
  • the detection unit 27 detects the potential difference between the first output electrode 22b and the second output electrode 22d.
  • the current control unit 28 controls the current flowing through the cancel coil 14 by the output signal of the detection unit 27.
  • the output converter 29 amplifies the voltage drop at the load resistor 30 due to the current flowing through the cancel coil 14 and outputs the amplified voltage drop to the output terminal 31.
  • the current I flows through the current line 11
  • the current I by the magnetic field H I is applied to the magnetic detection element 13 occurs
  • the magneto-resistive element 20a, with 20c of resistance decreases
  • the magnetoresistive element 20b, 20d of the resistor Becomes larger.
  • the balance of the magnetoresistive element bridge is broken, and a potential difference is generated between the first output electrode 22b and the second output electrode 22d.
  • This potential difference is detected by the detection unit 27 and input to the current control unit 28.
  • the current control unit 28 causes a current to flow through the cancel coil 14 based on this potential difference, generates a magnetic field H c by this current, and generates a net magnetic field applied to the magnetoresistive elements 20a to 20d from the thin film magnet 24.
  • the operation is performed so that the potential difference of the magnetoresistive element bridge becomes zero.
  • the magnetoresistive element bridge is balanced again, if the voltage generated at both ends of the load resistor 30 is monitored and amplified appropriately, a signal corresponding to the current flowing through the current line 11 is output to the output terminal 31. Become.
  • FIG. 8 is a perspective view of a current sensor according to Embodiment 3 of the present invention.
  • a current sensor 52 is installed on the current line 11 through which the current I flows.
  • FIG. 9 is a cross-sectional view showing the configuration of the current sensor 52.
  • the current sensor 52 includes a magnetic detection element 13, a cancel coil 14 that surrounds the magnetic detection element 13, and a magnetic yoke 53.
  • the current sensor 50 has lengths in the X-axis, Y-axis, and Z-axis directions of approximately 8 mm, 8 mm, and 4 mm, respectively.
  • FIG. 10 is a perspective view of the magnetic yoke according to the third embodiment of the present invention.
  • the magnetic yoke 53 is made of a magnetic material such as iron or an iron alloy.
  • the configuration of the magnetic yoke 53 will be described.
  • the magnetic yoke 53 has a first magnetic flux collecting portion 53a, a second magnetic flux collecting portion 53b, a first magnetic flux collecting portion 53a, and a second magnetic flux portion extending in parallel with the magnetic field to be measured with the cancel coil 14 interposed therebetween.
  • a third magnetic flux collector 53c sandwiched between one end of the magnetic flux collector 53b and substantially orthogonal, and a fourth magnet collector sandwiched between the other ends of the first magnetic flux collector 53a and the second magnetic flux collector 53b.
  • the magnetic part 53d is composed of connection parts 53e, 53f, 53g, and 53h that connect the first magnetic collecting part 53a, the second magnetic collecting part 53b, the third magnetic collecting part 53c, and the fourth magnetic collecting part 53d.
  • Each component of the magnetic yoke 53 is located on the same plane, and at least one of the third magnetic collecting portion 53c and the fourth magnetic collecting portion 53d extends in the direction of the magnetic detection element 13 to the inside of the cancel coil. ing.
  • the third magnetic flux collecting portion 53c of the magnetic yoke 53 surrounding the magnetic detection element 13 extends to the inside of the cancel coil 14 so as to overlap a part of the cancel coil 14.
  • the self-inductance of the cancel coil 14 is increased.
  • the compensation current passed through the cancel coil 14 necessary for canceling out the magnetic field of the same strength that flows through the magnetic detection element 13 is further reduced. Since the magnetic field to be measured can be canceled with a small compensation current, the power consumption of the current sensor can be further reduced.
  • the current sensor 52 is arranged on the current line 11, a current of 200 A is passed through the current line 11, and the cancel current necessary for canceling the measured magnetic field in the cancel coil 14 having a coil turn number of 190 turns.
  • the result of having measured is shown.
  • (1) is a comparative example, the measurement result of a magnetic yoke having a large middle leg
  • (2) is the measurement result of the present embodiment. Note that the distance between the middle legs is the distance between the third magnetic flux collector and the fourth magnetic flux collector.
  • (1) is a magnetic yoke having a large space between the middle legs, and both the third and fourth magnetic flux collectors do not extend to the inside of the cancel coil 14, and the third magnetic flux collector 53c and the fourth magnetic flux collector 4
  • the distance between the magnetic flux collecting portions 53d is 3.2 mm.
  • the magnetic yoke having a small middle leg is the present embodiment. In this measurement, both the third magnetic collecting portion 53c and the fourth magnetic collecting portion 53d extend to the inside of the cancel coil 14. The distance between the third magnetic flux collector 53c and the fourth magnetic flux collector 53d is 2.2 mm.
  • the power consumption in the cancel coil 14 can be reduced. It is conceivable that the magnetic field generated by the cancel coil 14 is efficiently applied to the magnetic detection element 13 by narrowing the distance between the middle legs.
  • the magnetoresistance of the path passing from the third magnetism collecting portion 53c to the fourth magnetism collecting portion 53d is the same as the magnetoresistance passing through the first magnetism collecting portion 53a and the second magnetism collecting portion 53a. Since the magnetic resistance is larger than the magnetic resistance passing through the magnetic part 53b, the magnetic flux passes through the first magnetic flux collecting part 53a rather than the path through the third magnetic flux collecting part 53c through the fourth magnetic flux collecting part 53d, and It concentrates on the path
  • the current sensor 52 in the present embodiment can be assembled by inserting the magnetic detection element 13 obliquely between the magnetic yoke 53 and the cancel coil 14 after the magnetic yoke 53 and the cancel coil 14 are assembled.
  • the third magnetic flux collector 53c extends to the inside of the cancel coil 14, but only the fourth magnetic flux collector 53d extends to the inside of the cancel coil 14, As shown in FIG. 12, the third magnetic flux collector 53 c and the fourth magnetic flux collector 53 d may both extend to the inside of the cancel coil 14.
  • the compensation current that flows through the cancel coil 14 is lower than that of the conventional magnetic yoke. Less power consumption even at high currents.
  • FIG. 13 is a cross-sectional view of a current sensor according to Embodiment 4 of the present invention.
  • FIG. 13 shows a view seen from above when the current sensor 54 is installed on the current line 11 through which the current I flows, and the current sensor 54 is cut horizontally.
  • FIG. 14 is a perspective view of a current sensor according to Embodiment 4 of the present invention.
  • the current sensor 54 includes a magnetic detection element 13, a cancel coil 14 that surrounds and surrounds the magnetic detection element 13, and a magnetic yoke 55.
  • the planar shape of the current sensor 54 is 8 mm ⁇ 8 mm, and the height is 4 mm. It has become.
  • the magnetic yoke 55 is made of a magnetic material such as iron or an iron alloy, and has a first magnetism collecting portion 55a extending outside the cancel coil 14 in the winding axis of the cancel coil 14 (in the same direction as the magnetic field induced by the current I), A second magnetic flux collecting portion 55b, a third magnetic flux collecting portion 55c and a fourth magnetic flux collecting portion 55d located on the extension line of the winding axis of the cancel coil 14, and a connecting portion 55e for connecting the respective magnetic flux collecting portions. 55f, 55g, 55h, and projections extending outward from the ends of the connecting portions 55e, 55f, 55g, 55h at both ends of the first magnetism collecting portion 55a and the second magnetism collecting portion 55b.
  • a portion 56 is provided.
  • the magnetic flux collecting section 55c and the fourth magnetic flux collecting section 55d are branched. For this reason, only the magnetic field flowing through the third magnetic flux collector 55c and the fourth magnetic flux collector 55d flows through the magnetic detection element 13.
  • projections 56 extending in the same direction as the magnetic field generated when the current I flows are provided at both ends of the first magnetism collecting part 55a and the second magnetism collecting part 55b, and the connecting parts 55e, 55f, 55g, It is configured to protrude from 55h. For this reason, the magnetic field generated when the current I flows flows more in the protruding portion 56, and the effect of the magnetic yoke 55 of the present embodiment can be increased.
  • the protrusion 56 has a width (in a direction perpendicular to the magnetic field generated when the current I flows) substantially the same as the width of the first magnetic collector 55a and the second magnetic collector 55b.
  • the length (the direction of the magnetic field generated when the current I flows) is preferably substantially the same as the length of the magnetic field generated when the current I of the connecting portions 55e, 55f, 55g, and 55h flows.
  • the magnetic detection element 13 may be saturated. It is possible to sufficiently detect the current.
  • the third magnetism collecting portion 55c and the fourth magnetism collecting portion 55d are arranged on the extension line of the winding axis of the cancel coil 14, thereby improving the magnetic efficiency and canceling. The current flowing through the coil 14 can be reduced.
  • a part of the cancel coil 14 overlaps the third magnetism collecting portion 55c and the fourth magnetism collecting portion 55d as shown in FIG. 15 (that is, the third magnetism collecting portion 55c). It is desirable that the fourth magnetic flux collector 55d extends to the inside of the cancel coil 14). By doing in this way, magnetic efficiency improves further and the electric current sent through the cancellation coil 14 can be reduced.
  • FIG. 5 is a perspective view of a current sensor according to Embodiment 5 of the present invention
  • FIG. 17 is a plan view of the current sensor according to Embodiment 5 of the present invention
  • FIG. 18 is a cross-sectional view taken along line 18-18 in FIG.
  • a current sensor 60 having a magnetic yoke 61 is arranged.
  • the current sensor 60 has lengths in the X-axis, Y-axis, and Z-axis directions of approximately 8 mm, 8 mm, and 4 mm, respectively.
  • the bobbin 63 insert-molds an input / output terminal (not shown) with a resin such as PET, and the magnetic detection element 13 is accommodated and disposed at a predetermined position inside the bobbin 63.
  • the cancel coil 14 is formed by winding a copper wire having an insulating surface on the outer periphery of the bobbin 63 so that its winding axis is perpendicular to the current I, that is, along the X-axis direction, and surrounds the magnetic detection element 13. .
  • the magnetic yoke 61 has a thickness of about 0.5 mm and is made of a high magnetic permeability material such as iron or an iron alloy.
  • the magnetic yoke 61 includes a first magnetic flux collector 61a, a second magnetic flux collector 61b, a third magnetic flux collector 61c, a fourth magnetic flux collector 61d, and connection portions 61e, 61f, 61g, and 61h. .
  • the components of these magnetic yokes 61 are located on the same plane.
  • the first magnetic flux collector 61a, the second magnetic flux collector 61b, the third magnetic flux collector 61c, and the fourth magnetic flux collector 61d extend substantially in parallel, and the first magnetic flux collector 61a and the third magnetic flux collector 61a.
  • the first magnetic flux collector 61a and the fourth magnetic flux collector 61d are connected to the first magnetic flux collector 61c, the second magnetic flux collector 61b, and the third magnetic flux collector 61c.
  • the connecting portion 61g is connected to the second magnetic flux collecting portion 61b and the fourth magnetic flux collecting portion 61d by the connecting portion 61h. Note that the broken lines in FIG. 17 are for easy understanding of the positional relationship of the above-described components.
  • the third magnetism collecting part 61c and the fourth magnetism collecting part 61d there is a gap between the third magnetism collecting part 61c and the fourth magnetism collecting part 61d, and the magnetoresistive elements 20a to 20d of the magnetic detecting element 13 are arranged in the gap. ing.
  • the direction in which the first magnetism collecting portion 61a and the second magnetism collecting portion 61b extend is the direction perpendicular to the current flowing through the current line 11, in other words, the current flowing through the current line 11. It is arranged so as to be in the same direction as the magnetic field due to the current to be measured.
  • the connecting portions 61e and 61h are provided with dividing portions 62a and 62b, and the magnetic yoke 61 is divided into at least two portions including one third magnetic collecting portion 61c or one fourth magnetic collecting portion 61d. Can be done.
  • the magnetic flux density in the first magnetic flux collecting portion 61a and the second magnetic flux collecting portion 61b of the integrated magnetic yoke is saturated and does not increase beyond a certain value. It becomes like this.
  • the magnetism detecting element 13 is sandwiched therebetween, and therefore the third magnetism collecting part 61c and the fourth magnetism collecting part 61d.
  • the current I is not proportional to the magnetic flux density generated between the third magnetic flux collector 61c and the fourth magnetic flux collector 61d, and the detection accuracy of the current I flowing through the current line 11 is reduced.
  • the connecting portions 61e and 61h have divided portions, and the magnetic yoke 61 has the third magnetic collecting portion 61c and the fourth magnetic collecting portion 61d has one.
  • the magnetic yoke is not saturated even when a larger current flows through the current line because it is divided into at least two parts including one, thereby reducing the size, high sensitivity, low power consumption, and current to be measured. It is possible to provide a current sensor having a large measurable range.
  • FIG. 19 shows the current I flowing in the current line 11 and the magnetic detection when the current sensor having an integrated magnetic yoke and the current sensor 60 in the present embodiment are arranged at a position 2 mm above the central axis of the current line 11. The deviation from the linearity of the magnetic flux density at the position of the element 13 is shown. When the current I flowing through the current line 11 and the magnetic flux density at the position of the magnetic detection element 13 are proportional, it is 0%.
  • the subscript (1) indicates a current sensor having an integral magnetic yoke
  • the subscript (2) indicates a current sensor 60 in the present embodiment. Referring to FIG.
  • the current sensor 60 in the present embodiment has a straight line of magnetic flux density at the position of the magnetic detection element 13 in a large current region of 1000 A or more than a current sensor having an integrated magnetic yoke without a dividing portion. It can be seen that the deviation from the sex is small.
  • the current sensor in the present embodiment since the current sensor in the present embodiment has the divided portion in the connecting portion of the magnetic yoke, the magnetic yoke does not saturate even when a larger current flows through the current line.
  • the power consumption is small due to the sensitivity, and the measurable range of the current to be measured can be increased.
  • an operation check coil is wound around the first magnetism collecting unit 61a and the second magnetism collecting unit 61b, and the operation check is performed when the current sensor is activated.
  • the self-diagnosis of the current sensor 60 can be performed.
  • the operation confirmation coil can be easily wound around the first magnetic collecting part 61a and the second magnetic collecting part 61b. .
  • the third magnetism collecting part 61 c and the fourth magnetism collecting part 61 d may enter the inside of the bobbin 63. Even in such a case, since the magnetic yoke 61 is divided into at least two parts, an effect of facilitating the assembly of the current sensor can be obtained.
  • the divided parts 62a and 62b are arranged in the connecting parts 61e and 61h shown in FIG. 17, but the same applies even if the divided parts 62a and 62b are arranged in the connecting parts 61e and 61g.
  • the effect of is obtained.
  • the first magnetic flux collector 61 a and the second magnetic flux collector 61 b are used. Even if only one of the two magnetic flux collecting portions 61b is used, the same effect can be obtained.
  • FIG. 20 is a perspective view of a current sensor according to Embodiment 6 of the present invention, in which a current sensor 65 is installed on a current line 11 through which a current I flows.
  • FIG. 21 is a diagram showing a configuration of the magnetic yoke 66 of the present embodiment, and the magnetic yoke 66 is configured by attaching a first magnetic yoke 67 and a second magnetic yoke 68 up and down.
  • the first magnetic yoke 67 includes a first magnetic flux collector 67a, a second magnetic flux collector 67b, and a first magnetic flux collector 67a that extend parallel to the magnetic field to be measured with the cancel coil 14 sandwiched outside the cancel coil 14. And a third magnetism collecting portion 67c sandwiched between one end of the second magnetism collecting portion 67b and substantially perpendicular to each other, and a second magnetism sandwiching between the other end of the first magnetism collecting portion 67a and the second magnetism collecting portion 67b.
  • first magnetic flux collectors 67a first magnetic flux collectors 67a
  • second magnetic flux collectors 67b third magnetic flux collectors 67c
  • connection portions 67e, 67f, 67g for connecting the fourth magnetic flux collectors 67d, 67h.
  • the constituent elements of the first magnetic yoke 67 are located on the same plane, and the third magnetic flux collector 67c extends in the direction of the magnetic detection element 13.
  • the second magnetic yoke 68 includes a first magnetic flux collector 68a and a second magnetic flux collector 68b extending in parallel with the magnetic field to be measured with the cancel coil 14 sandwiched outside the cancel coil 14, and a first magnetic flux collector 68.
  • a third magnetic flux collecting portion 68c sandwiched between one end of the first magnetic flux collecting portion 68b and the second magnetic flux collecting portion 68b, and a second substantially perpendicular portion sandwiched between the other ends of the first magnetic flux collecting portion 68a and the second magnetic flux collecting portion 68b.
  • Each component of the second magnetic yoke 68 is located on the same plane, and the fourth magnetic flux collector 68 d extends in the direction of the magnetic detection element 13.
  • the productivity of the current sensor 65 is improved as compared with the current sensor 52 of the third embodiment.
  • the magnetic yoke 53 is integrally formed. To assemble the current sensor 52, the magnetic detection element 13 must be inserted obliquely between the magnetic yoke 53 and the cancel coil 14. However, the process is complicated.
  • the magnetic yoke 66 is configured by bonding the first magnetic yoke 67 and the second magnetic yoke 68, assembly is easy.
  • the assembly process of the current sensor 65 of the present embodiment will be described below with reference to FIGS. 23A to 23D.
  • the magnetic detection element 13 and the cancel coil 14 are assembled, and the second magnetic yoke 68 is inserted from above the cancel coil 14.
  • FIG. 23B is a diagram in which the second magnetic yoke 68 is inserted from the side of the cancel coil 14 and the arrangement of the second magnetic yoke 68 is completed.
  • the first magnetic yoke 67 is disposed so as to overlap the second magnetic yoke 68 in the same manner as the steps of the second magnetic yoke 68 shown in FIGS. 23A to 23C.
  • the first magnetic yoke 67 and the second magnetic yoke 68 are pasted up and down to complete the current sensor 65 as shown in FIG. 23D.
  • the first magnetic yoke 67 and the second magnetic yoke 68 can be inserted into the cancel coil 14 and attached together.
  • a complicated process of inserting the magnetic detection element 13 obliquely after assembling the cancel coil 14 and the magnetic yoke 53 becomes unnecessary, and the assembly of the current sensor 65 is easy.
  • Productivity is improved as compared with the current sensor 52 of the third embodiment.
  • the magnetic yoke 66 is not configured by attaching the magnetic yokes up and down as in the present embodiment, but for example, the first magnetic collecting portion 53a and the second magnetic collecting portion 53a.
  • the magnetic yoke 53 is divided at the center of the magnetic flux collecting portion 53b, and the magnetic yokes divided from both sides in the winding axis direction of the cancel coil 14 are inserted and bonded to form a magnetic yoke.
  • dividing the magnetic yoke by the first and second magnetic flux collectors a gap is formed between the first and second magnetic flux collectors.
  • the gap formed in the first and second magnetic flux collectors has higher magnetic resistance than the first through fourth magnetic flux collectors, the magnetic flux passing through the first and second magnetic flux collectors is hindered by the gap. It becomes like this.
  • the magnetic flux passing through the third magnetic flux collector and passing through the magnetic detection element 13 is increased, so that the performance of the core is reduced and the current is reduced. The power consumption of the sensor will increase.
  • the gap formed in the divided parts This makes it difficult for the magnetic flux to pass through and increases the power consumption of the current sensor.
  • the magnetic yoke 66 in the present embodiment can improve productivity without increasing power consumption so much.
  • FIG. 22 shows the result of measuring the cancellation current of the coil necessary to cancel the magnetic field to be measured.
  • the measurement conditions are the same as in the third embodiment.
  • (1) and (2) are the same as in the third embodiment
  • (3) is the measurement result of the EE magnetic yoke divided by the first and second magnetic flux collectors
  • (4) is the stepped magnetism of the present embodiment. It is a measurement result of a yoke.
  • the distance between the third magnetic collecting part and the fourth magnetic collecting part of the EE magnetic yoke of (3) and the stepped magnetic yoke of (4) is 2 as in the case of the magnetic yoke having a small middle leg between (2). .2 mm.
  • the EE magnetic yoke of (3) requires 13.2 mA to cancel the measured magnetic field, and (1) there is more space between the middle legs than the large core, but this is the present embodiment (4).
  • the necessary canceling current of 5.8 mA is smaller than that of the EE magnetic yoke of (3), and the distance between the middle legs of (1) is smaller than that of the large magnetic yoke. From this, the power consumption of the current sensor is smaller when the magnetic yoke of the present embodiment is used than the EE magnetic yoke of (3) divided by the first magnetic flux collector and the second magnetic flux collector, and (1 It can be seen that the performance between the middle legs is better than that of the large core.
  • the compensation current that flows through the cancel coil 14 is lower than that of the conventional core. Less power consumption even with current. Further, by configuring the magnetic yoke 66 of the current sensor 65 by bonding the first magnetic yoke 67 and the second magnetic yoke 68, productivity can be improved.
  • FIG. 24 is a perspective view of a current sensor 70 according to Embodiment 7 of the present invention, which includes a first current detection element 70A and a second current detection element 70B.
  • the current sensor 70 is disposed on the current line 11 through which the current I flows in the Y-axis direction.
  • FIG. 25 is a cross-sectional view of the current sensor 70 according to the seventh embodiment of the present invention cut along a plane parallel to the XY plane
  • FIG. 26 is a diagram of the current sensor 70 according to the seventh embodiment of the present invention cut along the YZ plane. It is a longitudinal cross-sectional view.
  • the first current detection element 70A includes a magnetic detection element 13A including a magnetoresistor and a cancel coil 14A surrounding the magnetic detection element 13A.
  • the second current detection element 70B includes a magnetic detection element 13B including a magnetic resistor, a cancel coil 14B that surrounds the magnetic detection element 13B, and a magnetic yoke 72 that circulates around the magnetic detection element 13B.
  • the first current detection element 70A and the second current detection element 70B are the center in the width direction of the current line 11 having a rectangular cross section with lengths of 18 mm and 3 mm respectively in the X-axis and Z-axis directions made of copper or the like. At a position 2 mm from the surface.
  • the lengths of the magnetic yoke 72 in the X-axis and Y-axis directions are about 6 mm and 8 mm, respectively.
  • the first current detection element 70A and the second current detection element 70B are placed in the center in the width direction of the current line 11 at a position 2 mm from the surface, and the current I is passed through the current line 11.
  • the cancellation current i 14A to be passed through the cancellation coil 14A and the bridge circuit of the magnetic detection unit 23A of the second current detection element 70B This is a measurement of the cancel current i 14B to be passed through the cancel coil 14B in order to achieve equilibrium.
  • the cancel current i 14B to be passed through the cancel coil 14B to balance the bridge circuit of the magnetic detection element 13B of the second current detection element 70B is: In order to balance the bridge circuit of the magnetic detection element 13A of the first current detection element 70A arranged adjacent to the second current detection element 70B, about 1/5 of the cancellation current i 14A to be passed through the cancellation coil 14A. I understand that it will be completed.
  • the current sensor 70 monitors the cancel current i 14B flowing through the cancel coil 14B of the second current detection element 70B, so that the current I flowing through the current line 11 is small and the second current detection element 70B.
  • the cancel current i 14B flowing through the cancel coil 14B is smaller than a predetermined value
  • the output signal of the first current detection element 70A having good measurement sensitivity for a small current is used as the current detection output.
  • the current I flowing through the current line 11 increases and the cancellation current i 14B flowing through the cancellation coil 14B of the second current detection element 70B reaches a predetermined value, it flows through the cancellation coil 14A of the first current detection element 70A.
  • the output signal of the second current detection element 70B that requires a small canceling current to cut off the current and cancel the magnetic field generated by the current flowing through the current line 11 is defined as a current detection output.
  • FIG. 28 is a circuit diagram for explaining the operation of the current sensor 70 according to the seventh embodiment of the present invention.
  • the midpoint output of the bridge circuit in the first current detection element 70A is connected to a differential amplifier 80, and a cancel current generating circuit 81 is provided at the subsequent stage of the differential amplifier 80.
  • a first CMOS analog switch 82 in which NMOS and PMOS are connected in parallel is connected to the subsequent stage of the cancel current generating circuit 81.
  • the midpoint output of the bridge circuit in the second current detection element 70 ⁇ / b> B is connected to the differential amplifier 90, and a cancel current generating circuit 91 is provided at the subsequent stage of the differential amplifier 90.
  • a second CMOS analog switch 92 in which NMOS and PMOS are connected in parallel is connected to the subsequent stage of the cancel current generating circuit 91.
  • the resistor 83 is a resistor 83 having one end connected to the middle point of the first CMOS analog switch 82 and the second CMOS analog switch 92 and the other end grounded.
  • the resistor 83 is connected between the output of the cancel current generating circuit 91 and the ground.
  • a resistor 93 is connected. The potential generated at both ends of the resistor 93 is compared with a predetermined threshold voltage Va in the comparator 101.
  • the first and second CMOS analog switches 82 and 92 are controlled to open and close by the output of the comparator 101 and the inverted output of the inverter 102.
  • the midpoint potential of the first and second CMOS analog switches 82 and 92 is amplified by the amplifier 103 and output to the first output terminal 104. Further, the output of the inverter 102 is output to the second output terminal 105.
  • the second CMOS analog switch 92 is turned off, and the potential of the second output terminal 105 is low.
  • the output of the cancel current generating circuit 81 is connected to the resistor 63, so that the cancel current generating circuit 81 operates so that the cancel current i 14A flows through the cancel coil 14A and the output voltage of the bridge circuit becomes zero.
  • the voltage generated at both ends of the resistor 83 by the cancel current i 14A is amplified by the amplifier 103, and an output voltage corresponding to the current I flowing through the current line 11 is obtained at the first output terminal 104.
  • the output of the second output terminal 105 can be used as a range switching signal indicating that the signal appearing at the first output terminal 104 is a signal obtained from the first current detection element 70A.
  • the current I flowing through the current line 11 increases, and the voltage generated across the resistor 93 by the cancel current i 14B flowing through the cancel coil 14B of the second current detection element 70B is a predetermined threshold value of the + input terminal of the comparator 101.
  • the voltage Va becomes higher, the output of the comparator 101 is low, the first CMOS analog switch 82 is off, the second CMOS analog switch 92 is on, and the potential of the second output terminal 105 is high. It becomes.
  • the output of the cancel current generating circuit 81 is not connected to the resistor 83, and the output of the cancel current generating circuit 91 is connected to the resistor 83 and the resistor 93.
  • the voltage generated at both ends of the resistor 83 and the resistor 93 is amplified by the amplifier 103 by the cancel current i 14B, and an output voltage corresponding to the current I flowing through the current line 11 is obtained at the first output terminal 104.
  • the output of the second output terminal 105 can be used as a range switching signal indicating that the signal appearing at the first output terminal 104 is a signal obtained from the second current detection element 70B.
  • FIG. 29 shows an example in which the threshold voltage Va at the + input terminal of the comparator 101 is set so that the output of the comparator 101 falls low when the current flowing through the current line 11 exceeds 50 A.
  • the sum of the current I, the cancel current i 14A that should flow through the cancel coil 14A of the first current detection element 70A, and the cancel current i 14B that should flow through the cancel coil 14B of the second current detection element 70B changes It is the figure which showed whether to do. From this figure, it can be seen that the current I flowing in the current line 11 can be measured over a wide range while suppressing the total cancellation current to 6 mA or less.
  • the current sensor in the present embodiment can measure a wide range of current from low current to large current while suppressing the cancel current.
  • the maximum load current of the cancel current generating circuit can be kept low. Accordingly, it is possible to provide a current sensor that has low current consumption and a large dynamic range of current that can be measured. Further, since the distance between the first current detection element 70A and the current line 11 is substantially the same as the distance between the second current detection element 70B and the current line 11, the mounting is easy and the structure is compact. It can be done.
  • FIG. 30 shows a cross-sectional view of the current sensor according to Embodiment 7 of the present invention cut along a plane parallel to the XY plane.
  • this example is different from the above-described embodiment in that the second current detection element 70B is not provided with the magnetic yoke 72 that goes around the magnetic detection element 13B, and the second current detection element 70B
  • the number of turns of the cancel coil 14B is larger than the number of turns of the cancel coil 14A of the first current detection element 70A, and other configurations are the same as those shown in FIG.
  • the cancel coil 14A has 1000 turns and the cancel coil 14B has 5000 turns.
  • a cancel current to be supplied to cancel the magnetic field generated in the magnetic detection element 13B of the second current detection element 70B is The current can be made smaller than the cancel current that should be passed to cancel the magnetic field generated in the magnetic detection element 13A of the current detection element 70A. Thereby, the same effect as the example of FIG. 25 is acquired.
  • FIG. 31 shows a cross-sectional view of still another current sensor according to Embodiment 7 of the present invention cut along a plane parallel to the XY plane.
  • FIG. 31 this example is different from the above-described embodiment in that a magnetic yoke 71 that goes around the magnetic detection element 13A is arranged in the first current detection element 70A.
  • the magnetic yoke 71 has a thickness of about 1.5 mm and is made of a high magnetic permeability material such as iron or an iron alloy.
  • the magnetic yoke 71 includes a first magnetic flux collector 71a, a second magnetic flux collector 71b, 3 magnetism collecting portions 71c, a fourth magnetism collecting portion 71d, and connecting portions 71e, 71f, 71g, 71h. It should be noted that the broken lines in FIG. 31 are provided for easy understanding of the positional relationship of the above-described components.
  • the widths of the first magnetism collecting portion 71a and the second magnetism collecting portion 71b of the first current detecting element 70A are set to the widths of the first magnetism collecting portion 72a and the second magnetism collecting portion of the second current detecting element 70B.
  • the width of the third magnetism collecting part 71c and the fourth magnetism collecting part 71d of the first current detection element 70A is made smaller than the width of the magnetic part 72b, and the third current collection element 71B of the second current detection element 70B is made. It is made wider than the width of the magnetic part 72c and the fourth magnetic flux collecting part 72d.
  • the magnetic resistance of the first magnetism collecting part 71a and the second magnetism collecting part 71b of the first current detecting element 70A is set to be the first magnetism collecting part of the second current detecting element 70B.
  • 72a and the magnetic resistance of the second magnetic flux collector 72b, and the magnetic resistance between the third magnetic flux collector 71c and the fourth magnetic flux collector 71d of the first current detection element 70A is
  • the second current detecting element 70B The cancellation current to be flowed to cancel the magnetic field generated in the magnetic detection element 13B can be made smaller than the cancellation current to be flowed to cancel the magnetic field generated in the magnetic detection element 13A of the first current detection element 70A.
  • FIG. 32 is a perspective view of the current sensor according to the eighth embodiment of the present invention, in which the current sensor 112 is arranged on a plane perpendicular to the direction of the current I flowing through the current line 111.
  • the current line 111 is made of copper and has a rectangular shape with a cross section of 20 mm ⁇ 5 mm.
  • the current sensor 112 includes a flat magnetic yoke 115 surrounding the current line 111 and a gap portion provided in the magnetic yoke 115.
  • the magnetic detection element 13 is arranged at 116 and the cancel coil 14 surrounding the magnetic detection element 13.
  • the magnetic yoke 115 is formed by punching an iron-nickel alloy flat plate having a thickness of about 1 mm.
  • the width of the magnetic yoke 115 is about 6 mm, and the gap interval between the gap portions 116 is also about 6 mm.
  • Branch portions 117 are provided on both sides of the gap portion 116, and by setting the gap interval therebetween to about 2 mm, the magnetic resistance between the branch portions 117 becomes smaller than the gap portion 116. Yes. By doing so, a magnetic field is generated around the current I flowing through the current line 111, but the magnetic flux flows through the magnetic yoke 115 surrounding the current line 111.
  • a plurality of the magnetic detection elements 13 are desirably arranged so as to be substantially point-symmetric with respect to the center of the current line 111 as shown in FIG. By doing in this way, the influence of disturbances, such as geomagnetism, can be reduced and the accuracy of the current sensor 112 can be improved.
  • the direction in which magnetism is felt is the surface direction of the insulating substrate 121, so the magnetic detection element 13 is placed in the gap 116 of the magnetic yoke 115, the surface direction of the magnetic yoke 115 and the insulating substrate 121.
  • the magnetic detection element 13 is arranged so that the plane directions of the two are substantially parallel.
  • the assembly of the current sensor 112 can be facilitated, and deterioration of detection accuracy due to misalignment can be prevented. it can. Further, by making the magnetic yoke 115 and the magnetoresistive elements 20a to 20d (see FIG. 4A) on the same plane, the magnetic yoke 115 can be sufficiently functioned even if the thickness of the magnetic yoke 115 is reduced. Miniaturization of the sensor 112 can be realized.
  • the current sensor is disposed on one surface of the current line 11, but a similar current sensor may be disposed on the opposite surface.
  • the current line having a rectangular cross section is used, but a current line having a circular cross section may be used.
  • the same effect can be obtained by arranging the magnetic detection element in the radial direction of the current line.
  • the current sensor according to the present invention can handle a large current, can provide a small current sensor with low power consumption, and is industrially useful.

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  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
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  • Condensed Matter Physics & Semiconductors (AREA)
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Abstract

La présente invention porte sur un capteur de courant, qui comporte : un élément de détection magnétique, qui est disposé sur une surface d'une ligne de courant, et qui détecte un champ magnétique à mesurer, ledit champ magnétique étant généré du fait d'un courant circulant dans la ligne de courant ; et une culasse magnétique, qui est constituée par des première et deuxième sections de concentration de flux magnétique positionnées sensiblement parallèlement au champ magnétique à mesurer, une troisième section de concentration de flux magnétique positionnée dans la direction qui croise de façon sensiblement orthogonale la première et la deuxième sections de concentration de flux magnétique en étant prise en sandwich entre une extrémité de la première section de concentration de flux magnétique et une extrémité de la deuxième section de concentration de flux magnétique, une quatrième section de concentration de flux magnétique positionnée dans la direction croisant de façon sensiblement orthogonale la première et la deuxième sections de concentration de flux magnétique en étant prise en sandwich entre l'autre extrémité de la première section de concentration de flux magnétique et l'autre extrémité de la deuxième section de concentration de flux magnétique, et des sections de liaison qui relient la première section de concentration de flux magnétique, la deuxième section de concentration de flux magnétique, la troisième section de concentration de flux magnétique et la quatrième section de concentration de flux magnétique. L'élément de détection magnétique est disposé entre la troisième section de concentration de flux magnétique et la quatrième section de concentration de flux magnétique.
PCT/JP2011/005922 2010-11-01 2011-10-24 Capteur de courant WO2012060069A1 (fr)

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EP3156813A1 (fr) * 2015-10-16 2017-04-19 Johnson Electric S.A. Dispositif et procédé de détermination du courant
CN113495233A (zh) * 2020-03-18 2021-10-12 Tdk株式会社 磁场检测装置和电流检测装置

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Publication number Priority date Publication date Assignee Title
JP2015125019A (ja) * 2013-12-25 2015-07-06 株式会社東芝 電流センサ、電流測定モジュール及びスマートメータ
EP3156813A1 (fr) * 2015-10-16 2017-04-19 Johnson Electric S.A. Dispositif et procédé de détermination du courant
CN106597054A (zh) * 2015-10-16 2017-04-26 德昌电机(深圳)有限公司 电流测量装置及其方法
CN113495233A (zh) * 2020-03-18 2021-10-12 Tdk株式会社 磁场检测装置和电流检测装置
CN113495233B (zh) * 2020-03-18 2024-04-05 Tdk株式会社 磁场检测装置和电流检测装置

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