CN117269589A - Current measuring device - Google Patents

Current measuring device Download PDF

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Publication number
CN117269589A
CN117269589A CN202310179248.8A CN202310179248A CN117269589A CN 117269589 A CN117269589 A CN 117269589A CN 202310179248 A CN202310179248 A CN 202310179248A CN 117269589 A CN117269589 A CN 117269589A
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CN
China
Prior art keywords
current
air
coil
gap
magnetic field
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
CN202310179248.8A
Other languages
Chinese (zh)
Inventor
工藤高裕
山内芳准
石桥广脩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fuji Electric FA Components and Systems Co Ltd
Original Assignee
Fuji Electric FA Components and Systems Co Ltd
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 Fuji Electric FA Components and Systems Co Ltd filed Critical Fuji Electric FA Components and Systems Co Ltd
Publication of CN117269589A publication Critical patent/CN117269589A/en
Pending legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • 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
    • 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
    • G01R15/181—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using coils without a magnetic core, e.g. Rogowski coils
    • 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
    • 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
    • G01R15/202—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 Hall-effect devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16528—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values using digital techniques or performing arithmetic operations
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • G01R33/098—Magnetoresistive devices comprising tunnel junctions, e.g. tunnel magnetoresistance sensors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00—Cores, Yokes, or armatures

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
  • Measurement Of Current Or Voltage (AREA)

Abstract

The invention provides a current measuring device capable of measuring a current in a wide range from a small current to a large current. The current measuring apparatus includes: a magnetic-collecting core (3) that is disposed so as to surround the periphery of the conductor (2) through which the measurement current flows, that collects and induces a magnetic field generated around the conductor (2), and that is provided with at least 1 gap (G) at a portion through which the induced magnetic field passes; an air-core coil (4) provided in the gap (G) and detecting an induced voltage generated by the induced magnetic field; a coil bobbin around which the air-core coil (4) is wound, and which fixes the air-core coil (4) to the gap (G); and an integrating circuit (5) for calculating a measurement current based on the induced voltage detected by the air-core coil (4).

Description

Current measuring device
Technical Field
The present invention relates to a current measuring device capable of measuring a wide range of currents from a small current to a large current.
Background
Conventionally, as a current measuring apparatus, there is an apparatus for measuring a wide current range using a rogowski coil, for example (see patent document 1). The rogowski coil is a loop-shaped air core coil, and detects an induced voltage caused by a magnetic flux generated by a current flowing through a current line passing through the air core coil. Since the induced voltage increases as the frequency of the current increases, the frequency characteristic of the induced voltage is corrected by using an integrator circuit having a higher loss as the frequency increases, and the frequency characteristic of the entire detected induced voltage is flattened.
A current transformer type current measuring apparatus is known in which a measured current is measured by winding a coil that is magnetically coupled to a magnetic core body that surrounds a wire through which the measured current flows. The current measuring apparatus has high sensitivity for measuring current, and is therefore suitable for measuring small current. On the other hand, a current measurement device using a rogowski coil has low sensitivity for measuring a current, and is therefore suitable for measuring a large current, and can perform a wide-range current measurement.
Patent document 2 discloses a current measuring apparatus using a magnetic sensor having high sensitivity for measuring a current.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2000-310654
Patent document 2: japanese patent laid-open No. 2020-85906
Disclosure of Invention
Technical problem to be solved by the invention
Further, since the current measurement device using the rogowski coil has low sensitivity for measuring the current, it can measure a wide range of current up to a large current, but cannot measure a small current with high accuracy. On the other hand, as described above, the current transformer type current measuring apparatus and the current measuring apparatus of the magnetic sensor have high sensitivity to the measured current, and thus can perform current measurement of a small current, but cannot perform current measurement of a wide range up to a large current.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a current measuring device capable of measuring a current in a wide range from a small current to a large current.
Technical means for solving the technical problems
In order to solve the above problems, the present invention provides: a core body that is disposed so as to surround a periphery of a conductor through which a measurement current flows, that collects and senses a magnetic field generated around the conductor, and that is provided with at least 1 gap at a portion through which the sensed magnetic field passes; an air core coil provided in the gap and detecting an induced voltage generated by the induced magnetic field; a bobbin around which the air-core coil is wound and which fixes the air-core coil to the gap; and an integrating circuit that calculates the measurement current based on the induced voltage detected by the air-core coil.
The present invention is also characterized by comprising: a core body that is disposed so as to surround a periphery of a conductor through which a measurement current flows, that collects and senses a magnetic field generated around the conductor, and that is provided with at least 1 gap at a portion through which the sensed magnetic field passes; an air core coil provided in the gap and detecting an induced voltage generated by the induced magnetic field; a bobbin around which the air-core coil is wound and which fixes the air-core coil to the gap; an integrating circuit that calculates the measurement current based on the induced voltage detected by the air-core coil; a magnetic sensor disposed inside the coil bobbin and configured to detect an induced voltage generated by an induced magnetic field; and an amplifying circuit that calculates the measurement current based on the induced voltage detected by the magnetic sensor.
In the above invention, the magnetic sensor is used to measure the measurement current in the low current region, and the air-core coil is used to measure the measurement current in the high current region exceeding the low current region.
Further, the present invention is characterized in that, in the above-described invention, the magnetic sensor is a magnetic sensor to which a tunnel magnetoresistance effect is applied.
In the above invention, the core-collecting body is コ -shaped.
Effects of the invention
According to the present invention, a wide range of current measurement from a small current to a large current can be performed in a small size.
Drawings
Fig. 1 is a schematic diagram showing the structure of a current measuring apparatus according to embodiment 1 of the present invention.
Fig. 2 is a perspective view showing the structure of the current measuring apparatus according to embodiment 1 of the present invention.
Fig. 3 is a graph showing the relationship between the output voltage of the integrating circuit and the measured current.
Fig. 4 is a schematic diagram showing the structure of a current measuring apparatus according to embodiment 2 of the present invention.
Fig. 5 is a perspective view showing the structure of the bobbin shown in fig. 4.
Fig. 6 is a cross-sectional view showing a state in which the magnetic sensor shown in fig. 4 is disposed in a coil bobbin.
Fig. 7 is a diagram showing the relationship between the output voltages of the integrating circuit and the amplifying circuit and the measured current.
Fig. 8 is a graph showing the change of the output voltage of the TMR magnetic sensor and the hall element with respect to the change of temperature.
Detailed Description
The mode for carrying out the present invention will be described below with reference to the accompanying drawings.
Embodiment 1
Fig. 1 is a schematic diagram showing the structure of a current measuring apparatus 1 according to embodiment 1 of the present invention. Fig. 2 is a perspective view showing the structure of the current measuring device 1 according to embodiment 1 of the present invention. As shown in fig. 1 and 2, the current measuring apparatus 1 includes a core assembly 3, an air core coil 4, a coil bobbin 8, an integrating circuit 5, and a circuit board 9. The magnetism collecting core 3 is disposed so as to surround the periphery of the conductor 2 through which the measurement current flows, and collects and senses a magnetic field generated around the conductor 2, and at least 1 gap G is provided at a portion through which the sensed magnetic field passes. The core 3 is made of a soft magnetic material, for example, and has a コ shape. The shape of the core 3 is not limited to コ, and may be, for example, a circular shape or an elliptical shape having the gap G. The core body 3 is laminated or integrally formed. The magnetism collecting core 3 forms a loop of the magnetic flux 7 with respect to the magnetic field after magnetism collection through the gap G.
The air core coil 4 is provided in the gap G, and detects an induced voltage generated by an induced magnetic field (magnetic flux). The air coil 4 may also be referred to as a part of a rogowski coil arranged in a loop. In the bobbin 8, the hollow coil 4 is wound, and the hollow coil 4 is positioned to the gap G and fixed to the core assembly 3. The gap G is an end portion of the コ -shaped core body 3 on the open end side (-Z direction side) and is a portion through which the magnetic flux 7 passes. The gap G shown in fig. 1 is linear in the ±y directions, and the air coil 4 is also a linear coil.
The integrating circuit 5 is connected to the air-core coil 4, calculates a measurement current flowing through the conductor 2 based on the induced voltage detected by the air-core coil 4, and outputs the measurement current as an output voltage corresponding to the measurement current from the output terminal T1. Here, the integrating circuit 5 converts the frequency characteristic of the detected induced voltage into a flat value and outputs the flat value as an output voltage corresponding to the measured current. The circuit board 9 is a board to which the coil bobbin 8 and the integrating circuit 5 are connected and mounted.
Fig. 3 is a diagram showing a relationship between the output voltage of the integrating circuit 5 and the measured current. In fig. 3, a characteristic curve L1 shows a relationship between the output voltage Vout and the measurement current I generated in embodiment 1. The characteristic curve L100 shows the relationship between the output voltage Vout and the measured current I generated by the air-only coil 4 in which the core 3 is not provided. The output voltage Vout is equal to or lower than the power supply voltage Vmax of the integrating circuit 5. As shown in fig. 3, in the current measuring apparatus 1 according to embodiment 1, the sensitivity of the output voltage Vout to the measured current I becomes higher than that of the current measuring apparatus in which only the air-core coil 4 of the core body 3 is not provided, and the current range that can be measured is extended toward the small current region side, so that a wide-range current measurement can be performed. This is because the magnetic flux 7 in the core collecting body 3 increases in proportion to the magnitude of the magnetic permeability of the magnetic material constituting the core collecting body 3, and thus the sensitivity to the measurement current is improved as compared with the case where only the air core coil 4 of the core collecting body 3 is not provided.
In embodiment 1, in order to induce a magnetic field generated around the conductor 2 through which the measurement current flows, the core body 3 having the gap G is provided so as to surround the conductor 2, and the induced voltage is detected by the air core coil 4 with respect to the magnetic field generated in the gap G, so that the measurement of the current in a wide range can be performed with a small-sized air core coil.
Embodiment 2
In embodiment 2, the configuration of embodiment 1 is such that the magnetic sensor 11 is provided in the hollow coil 4, and the hollow coil 4 and the magnetic sensor 11 are used together, whereby the current measurement range on the small current region side is further extended by the magnetic sensor 11. Fig. 4 is a schematic diagram showing the structure of a current measuring apparatus 10 according to embodiment 2 of the present invention. Fig. 5 is a perspective view showing the structure of the bobbin 8 shown in fig. 4. Fig. 6 is a cross-sectional view showing a state in which the magnetic sensor 11 shown in fig. 4 is disposed in the coil bobbin 8.
As shown in fig. 4 to 6, the current measuring apparatus 10 further includes a magnetic sensor 11 and an amplifying circuit 12 with respect to the configuration of the current measuring apparatus 1. The magnetic sensor 11 is disposed in the hollow cylinder 20 around which the hollow coil 4 is wound near the center of the coil bobbin 8, and detects an induced voltage generated by the magnetic flux collected by the magnetic collection core 3. The magnetic sensor 11 is mounted on a circuit board 13 fixedly disposed in the hollow cylinder 20. The amplifying circuit 12 is provided on the circuit board 9, is connected to the magnetic sensor 11 via the circuit board 13, amplifies the induced voltage detected by the magnetic sensor 11, and outputs the amplified induced voltage as an output voltage corresponding to the measured current from the output terminal T2.
Fig. 7 is a diagram showing the relationship between the output voltages of the integrating circuit 5 and the amplifying circuit 12 and the measured current. In fig. 7, a characteristic curve L1 shows a relationship between the output voltage Vout and the measurement current I generated by the air-core coil 4 according to embodiment 2. Further, the characteristic curve L10 shows the relationship of the output voltage Vout with respect to the measurement current I generated by the magnetic sensor 11.
As shown by the characteristic curve L10, the magnetic sensor 11 has higher sensitivity to a magnetic field than the air-core coil 4, and therefore, can obtain a large output voltage in a small current region EA where the measurement current including 0 is small, but the output voltage Vout is saturated in a large current region EB exceeding the small current region EA. On the other hand, as shown by the characteristic curve L1, the output voltage obtained by the air-core coil 4 is outputted linearly from the middle of the small current region EA to the large current region EB without being saturated. Therefore, by performing current measurement in which the magnetic sensor 11 and the air-core coil 4 are combined, current measurement of a wide range of measurement currents can be performed in a small size. The current measurement by the magnetic sensor 11 is set to be at least until the saturation current I1 at which the output voltage is saturated. That is, the current measurement result obtained by the magnetic sensor 11 may be used up to the saturation current I1, and when the saturation current I1 is exceeded, the current measurement result obtained by the air-core coil 4 may be used.
Fig. 8 is a graph showing the change of the output voltage of the TMR magnetic sensor (magnetic sensor 11) and the hall element (magnetic sensor 11') with respect to the change of temperature. As the magnetic sensor 11, there are a sensor (hall element) utilizing the hall effect, a sensor utilizing the magnetoresistance effect (MI effect), and the like. In embodiment 2, as the magnetic sensor 11, a TMR magnetic sensor that applies a tunnel magnetoresistance effect (TMR effect) is used. TMR magnetic sensors have a structure in which 2 pieces of a non-magnetic insulating film, which is extremely thin on the order of several nanometers, are sandwiched between two magnetic films, and are smaller in size and higher in sensitivity to magnetic fields than general magnetic sensors.
As shown in fig. 8, the TMR magnetic sensor is less susceptible to temperature change than the hall element, and since the change in output voltage with respect to temperature change is small, it is possible to perform high-precision current measurement.
The above-described embodiments and the respective structures shown in the drawings are functional overview, and are not necessarily physically arranged as shown in the drawings. That is, the manner of separating and coupling the respective devices and components is not limited to the illustrated one, and all or a part thereof may be functionally or physically separated and coupled in any unit according to various use conditions and the like.
Description of the reference numerals
1. 10 current measuring device
2. Conductor
3. Magnetic core
4. Hollow coil
5. Integrating circuit
7. Magnetic flux
8. Coil pipe
9. 13 circuit substrate
11. 11' magnetic sensor
12. Amplifying circuit
20. Hollow cylinder
EA low current region
EB high current region
G gap
I measuring current
I1 saturation current
Characteristic curves of L1, L10 and L100
T1, T2 output terminal
Vmax supply voltage
Vout output voltage.

Claims (5)

1. A current measurement device, comprising:
a core body that is disposed so as to surround a periphery of a conductor through which a measurement current flows, that collects and senses a magnetic field generated around the conductor, and that is provided with at least 1 gap at a portion through which the sensed magnetic field passes;
an air core coil provided in the gap and detecting an induced voltage generated by the induced magnetic field;
a bobbin around which the air-core coil is wound and which fixes the air-core coil to the gap; and
and an integrating circuit for calculating the measurement current based on the induced voltage detected by the air-core coil.
2. A current measurement device, comprising:
a core body that is disposed so as to surround a periphery of a conductor through which a measurement current flows, that collects and senses a magnetic field generated around the conductor, and that is provided with at least 1 gap at a portion through which the sensed magnetic field passes;
an air core coil provided in the gap and detecting an induced voltage generated by the induced magnetic field;
a bobbin around which the air-core coil is wound and which fixes the air-core coil to the gap;
an integrating circuit that calculates the measurement current based on the induced voltage detected by the air-core coil;
a magnetic sensor disposed inside the coil bobbin and configured to detect an induced voltage generated by an induced magnetic field; and
and an amplifying circuit that calculates the measurement current based on the induced voltage detected by the magnetic sensor.
3. The current measuring apparatus according to claim 2, wherein,
and measuring a measurement current in a low current region by using the magnetic sensor, and measuring a measurement current in a high current region exceeding the low current region by using the hollow coil.
4. A current measuring apparatus according to claim 2 or 3, wherein,
the magnetic sensor is a magnetic sensor that uses tunnel magnetoresistance effect.
5. A current measuring apparatus according to any one of claim 1 to 3, wherein,
the magnetic core body is コ -shaped.
CN202310179248.8A 2022-06-21 2023-02-27 Current measuring device Pending CN117269589A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022099635A JP2024000752A (en) 2022-06-21 2022-06-21 Current measurement device
JP2022-099635 2022-06-21

Publications (1)

Publication Number Publication Date
CN117269589A true CN117269589A (en) 2023-12-22

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ID=89207003

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310179248.8A Pending CN117269589A (en) 2022-06-21 2023-02-27 Current measuring device

Country Status (4)

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JP (1) JP2024000752A (en)
KR (1) KR20230174695A (en)
CN (1) CN117269589A (en)
TW (1) TW202401018A (en)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3410043B2 (en) 1999-04-28 2003-05-26 三菱電機株式会社 Current detection system
FR3089013B1 (en) 2018-11-22 2021-01-29 Valeo Siemens Eautomotive France Sas MAGNETIC CORE FOR CURRENT MEASURING SENSOR

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TW202401018A (en) 2024-01-01
JP2024000752A (en) 2024-01-09
KR20230174695A (en) 2023-12-28

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