WO2011125431A1 - 磁気コア、当該磁気コアを備えた電流センサ、及び電流測定方法 - Google Patents
磁気コア、当該磁気コアを備えた電流センサ、及び電流測定方法 Download PDFInfo
- Publication number
- WO2011125431A1 WO2011125431A1 PCT/JP2011/056119 JP2011056119W WO2011125431A1 WO 2011125431 A1 WO2011125431 A1 WO 2011125431A1 JP 2011056119 W JP2011056119 W JP 2011056119W WO 2011125431 A1 WO2011125431 A1 WO 2011125431A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- magnetic core
- holding hole
- magnetic
- open end
- element holding
- Prior art date
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
- G01R15/207—Constructional details independent of the type of device used
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/20—Instruments transformers
- H01F38/22—Instruments transformers for single phase ac
- H01F38/28—Current transformers
- H01F38/30—Constructions
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/20—Instruments transformers
- H01F38/22—Instruments transformers for single phase ac
- H01F38/28—Current transformers
- H01F38/30—Constructions
- H01F2038/305—Constructions with toroidal magnetic core
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F3/00—Cores, Yokes, or armatures
- H01F3/10—Composite arrangements of magnetic circuits
- H01F3/14—Constrictions; Gaps, e.g. air-gaps
Definitions
- the present invention relates to a magnetic core capable of increasing the detection sensitivity of a current sensor, a current sensor including the magnetic core, and a current measurement method.
- Patent Document 1 In recent years, current sensors are used in many industrial fields, and demands for higher sensitivity are increasing year by year. Therefore, various current sensors have been developed to achieve high sensitivity, and an example thereof is disclosed in Patent Document 1.
- the earth leakage sensor disclosed in Patent Document 1 includes a ring-shaped magnetic body (magnetic core) that senses a change in a magnetic field, and a magneto-impedance element that is added to the sensor and whose impedance changes due to a change in the magnetic field generated by the sensor. And a detector for detecting the impedance change of the magnetic impedance element.
- FIG. 17 is a diagram showing a structure of a conventional magnetic core described in Patent Document 1.
- FIG. 17A shows a magnetic core 100a provided with a cutting portion 101, and the cutting portion 101 has a magnetic impedance element 103.
- FIG. It is the schematic which shows a mode that was mounted.
- FIG. 17B is a schematic view showing a state in which the notch 102 is provided in the magnetic core 100 a and the magnetic impedance element 103 is placed in the notch 102.
- the above configuration realizes a current sensor that more efficiently transmits a change in the magnetic field of the magnetic core 100a (100b) to the magnetic impedance element 103.
- Japanese Patent Laid-Open No. 10-232259 (published on September 2, 1998) Japanese Patent Laid-Open No. 2005-49311 (published February 24, 2005)
- the leakage sensor including the magnetic core 100a of FIG. 17A has a problem that the detection sensitivity is low.
- a cutout portion 102 that cuts out a part of the magnetic core 100b is formed along the outer edge of the magnetic core 100b, and the magnetic impedance element 103 is placed on the cutout portion 102.
- the magnetic flux detected by the magneto-impedance element 103 is very small.
- the leakage sensor provided with the magnetic core 100b of FIG. 17B has a problem that the detection sensitivity is lowered.
- each of the leakage sensors including the conventional magnetic core 100a (100b) has low sensitivity, and when measuring a current of several tens mA level, there is a problem that a value to be detected is buried in noise. .
- Patent Document 2 also discloses a current sensor with high sensitivity.
- the current sensor of Patent Document 2 has a problem in that the magnetic core is shielded with a shield plate to improve noise resistance, which causes another problem of increasing the size and cost of the current sensor. .
- the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a magnetic core capable of increasing the detection sensitivity of the current sensor, a current sensor including the magnetic core, and a current measurement method. It is to provide.
- a magnetic core according to the present invention is a magnetic core used in a current sensor in order to solve the above-described problem, and a first open end surface in which a first element holding hole for holding a magnetoelectric conversion element is formed. And a second open end face facing the first open end face, in which a second element holding hole for holding the magnetoelectric conversion element is formed.
- the magnetic core according to the present invention has a first open end face and a second open end face facing each other.
- a first element holding hole is formed in the first open end face
- a second element holding hole is formed in the second open end face
- the magnetoelectric conversion element is held in the first element holding hole and the second element holding hole.
- the presence of the first open end surface and the second open end surface that is, the presence of a gap (hereinafter referred to as “magnetic flux leakage portion”) between the first open end surface and the second open end surface.
- magnetic flux leakage portion a gap between the first open end surface and the second open end surface.
- the sensitivity of the magnetic core is better when the magnetic resistance of the magnetic flux leaking portion is lower, and when the width of the magnetic flux leaking portion (distance between the first open end surface and the second open end surface) is narrower, the magnetic flux leak The magnetoresistance at the entrance is reduced.
- the magnetoelectric conversion element is held in the first element holding hole and the second element holding hole formed in the first open end face and the second open end face. Therefore, the distance between the first open end face and the second open end face does not need to be so wide that the magnetoelectric conversion element is placed between them.
- the width of the magnetic flux leakage portion is narrow, and hence the magnetic resistance of the magnetic flux leakage portion is also reduced, so that the sensitivity of the current sensor using the magnetic core can be improved.
- the magnetic core according to the present invention has the conventional problem described with reference to FIG. 17A (the magnetoelectric conversion element is provided in the cut portion, and therefore the width of the cut portion must be widened). Therefore, it is possible to solve the problem that the sensitivity of the magnetic core decreases accordingly.
- the first element holding hole and the second element holding hole are not positioned along the outer edge of the magnetic core where magnetic flux is difficult to leak from the magnetic core, but the first open end face and the second open end face. Is formed.
- the magnetoelectric conversion element is held in the first element holding hole and the second element holding hole where magnetic flux easily leaks from the magnetic core, and is generated by a minute current. Sensitivity can be improved by collecting more magnetic flux in the magnetoelectric transducer.
- the magnetic core according to the present invention has the conventional problem described with reference to FIG. 17B (the magnetic core is placed on the notch formed along the outer edge of the magnetic core. Therefore, it is possible to solve the problem that the magnetic flux is difficult to leak from and the magnetic flux detected by the magnetoelectric conversion element becomes minute, thereby reducing the sensitivity of the magnetic core.
- the magnetic core according to the present invention can realize a magnetic core capable of increasing the detection sensitivity of the current sensor with the above-described configuration.
- the magnetic core according to the present invention has the following effects.
- the conventional current sensor does not have a structure (function) that realizes noise immunity in the magnetic core itself. Therefore, when measuring a current of several tens of mA, it is affected by an external magnetic field, and the current can be measured with high detection sensitivity. could not.
- the magnetic flux leakage portion serves as a shield against an external magnetic field generated by geomagnetism or an external current. Therefore, the magnetic core according to the present invention can also solve the conventional problem that miniaturization and cost reduction are hindered by covering the magnetic core with a shield material.
- the magnetoelectric conversion element in the first element holding hole and the second element holding hole, is arranged such that the magnetosensitive direction of the magnetoelectric conversion element is the circumferential direction of the magnetic core.
- the configuration may be held.
- the magnetic core according to the present invention can realize a magnetic core that can further increase the detection sensitivity of the current sensor.
- the magnetic core according to the present invention may be configured such that the first element holding hole and the second element holding hole are filled with a low permeability material having a lower permeability than the magnetic core.
- the sensitivity can be improved at the same magnification as the relative permeability of the low permeability material.
- the magnetic core according to the present invention may be configured such that a low permeability material having lower permeability than the magnetic core is filled between the first open end face and the second open end face. .
- the magnetic core which can further raise the detection sensitivity of a current sensor by setting it as the said structure is realizable.
- the low magnetic permeability material may be a ferrite-containing epoxy resin, a magnetic fluid, or air.
- PB permalloy, PC permalloy, amorphous, silicon steel plate and the like are known. Any material can be used for the magnetic core according to the present invention. And as a low-permeability material having a lower magnetic permeability than such a magnetic core, ferrite-containing epoxy resin, magnetic fluid, or air can be cited.
- a magnetic core capable of further enhancing the detection sensitivity of the current sensor is realized by filling the first element holding hole and the second element holding hole with a ferrite-containing epoxy resin, a magnetic fluid, or air. be able to.
- the side surface facing the side surface forming the second element holding hole is the first side surface
- the second element holding hole is formed.
- the first element holding hole and the second element holding hole have a hole width in the thickness direction of the magnetoelectric conversion element to be held.
- the distance between the first side surface and the second side surface is preferably 1.75 times or less.
- the distance between the first open end face and the second open end face is preferably smaller than 2 mm.
- the magnetoelectric conversion element is held in the first element holding hole and the second element holding hole.
- the magnetoelectric conversion element has an effect of reliably detecting the magnetic flux leaking from the magnetic core with respect to the first element holding hole and the second element holding hole.
- the first open end face and the second open end face may be configured such that parts thereof are in contact with each other.
- Various types such as an integral type, a laminated type, and a docking type are known as general magnetic core structures, and the magnetic core according to the present invention can be applied to any type.
- any type of magnetic core it may be difficult to manufacture and process the first open end face and the second open end face without contacting them at all.
- the magnetic core according to the present invention even if the first open end surface and the second open end surface are in contact with each other, the first element holding hole and the second element are interposed via the magnetic flux leakage portion. Since the magnetic flux leaks from the magnetic core to the element holding hole, the magnetoelectric conversion element can sense the leakage of the magnetic flux. Therefore, when it is difficult to manufacture and process the first open end face and the second open end face without making any contact, they can be used as they are. As a result, it is possible to realize a magnetic core capable of increasing the detection sensitivity of the current sensor, eliminate the need for an additional manufacturing / processing step, and reduce the price.
- the first element holding hole and the second element holding hole are configured to extend along a direction parallel to the thickness direction of the magnetic core at the first open end face and the second open end face, respectively. It's okay.
- the first element holding hole and the second element holding hole are respectively perpendicular to the thickness direction of the magnetic core at the first open end face and the second open end face. It may be the structure extended along.
- various types such as an integral type, a laminated type, and a docking type are known as general magnetic core structures.
- a laminated magnetic core when a laminated magnetic core is manufactured, a plurality of layers in which the first element holding hole and the second element holding hole are formed at the same place are prepared, and the layers are sequentially laminated.
- a magnetic core can be manufactured easily and at low cost. Even when the magnetic core is manufactured as an integral type or a docking type, the magnetic core can be manufactured easily and at low cost by adopting the above configuration. Thereby, a magnetic core suitable for mass production can be realized.
- the current sensor according to the present invention is preferably configured to include the magnetic core.
- the current measurement method according to the present invention includes: It is preferable to measure the current value of the current flowing through the wire to be measured by a current sensor including the magnetic core.
- the magnetic core according to the present invention includes the first open end surface in which the first element holding hole for holding the magnetoelectric conversion element is formed, and the second element for holding the magnetoelectric conversion element. And a second open end face facing the first open end face in which a holding hole is formed.
- FIG. 1A is a top view of the magnetic core
- FIGS. 2B and 2C are cross-sectional views along AA ′ in FIG. Show.
- FIG. 17B shows the measurement results using the known magnetic core of FIG. 17B
- FIG. 17B shows the measurement results using the known magnetic core of FIG. 17B
- 17C shows the measurement results of the magnetic core in which the magnetic core of FIG.
- the measurement result by the magnetic core when the element holding hole is formed in parallel with the measured electric wire (e) shows the magnetism when the element holding hole is formed in the direction perpendicular to the measured electric wire.
- FIG. 1 It is a figure which shows the measurement result of the magnetic flux density using the magnetic core which concerns on this invention, (a) is a figure for showing the definition of each symbol, (b) is a magnetic flux when changing L2. (C) is a graph showing the magnetic flux density when L1 is changed. It is a figure which shows the magnetic core of a gap structure and a butting structure based on this invention, (a) is a magnetic core of a gap structure, (b) is 1st open end surface and 2nd open end surface. (C) is a figure which shows the magnetic core of the butting structure which the 1st open end surface and the 2nd open end surface are contacting in 16 places, respectively.
- FIG. 17B shows the measurement results using the known magnetic core of FIG. 17B
- FIG. 17C shows the measurement results of the magnetic core in which the magnetic core of FIG. The measurement results using the magnetic core are respectively shown.
- FIG. 20 is a cross-sectional view of the internal structure of the current sensor in the horizontal direction of FIG. It is an assembly exploded view of the current sensor according to the present embodiment. It is a block diagram for demonstrating operation
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a front view.
- the magnetic core of FIG. 25 is shown, (a) is a perspective view, and (b) is an enlarged view of a magnetic flux leakage portion and an element holding hole.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is an elevation, (b) is sectional drawing, (c) shows a perspective view.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is an elevation, (b) is sectional drawing, (c) shows a perspective view.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is an elevation, (b) is sectional drawing, (c) shows a perspective view.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows sectional drawing.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows sectional drawing.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows sectional drawing.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows sectional drawing.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a perspective view, (b) shows a top view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a perspective view, (b) shows a top view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows an elevation view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows an elevation view.
- One shape of the magnetic core according to the present embodiment is shown, (a) is a perspective view of the magnetic core of FIG. 36, and (b) is a perspective view of the magnetic core of FIG.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view.
- One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a top view, (b) shows a perspective view. One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a perspective view, (b) shows the enlarged view of a magnetic flux leak part and an element holding hole.
- FIG. 1 One shape of the magnetic core which concerns on this Embodiment is shown, (a) is a perspective view, (b) shows the enlarged view of a magnetic flux leak part and an element holding hole. It is a figure for demonstrating that the sensitivity of a current sensor provided with the said magnetic core does not fall even if the thickness of a magnetic core is small, (a) shows a perspective view, (b) shows sectional drawing.
- Magnetic core 1 [1-1. Schematic structure of magnetic core 1]
- the schematic structure of the magnetic core 1 according to the present embodiment will be described.
- the current sensor including the magnetic core 1 will be described first, and then the schematic structure of the magnetic core 1 will be described.
- a magnetic core formed of a magnetic material amplifies the magnetic field generated from the current of the wire to be measured.
- the magnetoelectric transducer detects the magnetic flux density of the amplified magnetic field and converts it into an electrical signal. Thereafter, the electrical signal is processed by the output signal processing circuit, and the current value of the measured wire is measured.
- the magnetic core 1 is related to the magnetic core of the current sensor, and a leakage sensor can be cited as one of the uses of the current sensor.
- the current sensor according to the present embodiment includes, for example, detection of leakage of power conditioners such as solar cells and fuel cells, battery monitoring mounted on a hybrid car or a plug-in hybrid car, or battery monitoring of a data center UPS. It can be used in a wide range of fields.
- power conditioners such as solar cells and fuel cells
- battery monitoring mounted on a hybrid car or a plug-in hybrid car or battery monitoring of a data center UPS. It can be used in a wide range of fields.
- FIG. 1 is a diagram showing a schematic structure of a magnetic core 1.
- FIG. 1 (a) is a top view of the magnetic core 1
- FIG. 1 (b) is a perspective view of the magnetic core 1
- FIG. c) is an enlarged view of the characteristic part of the magnetic core 1.
- the magnetic core 1 is arranged in an annular shape so as to surround an axis around the current flow direction in the measured electric wire P.
- the magnetic core 1 includes a first open end face 3a in which a first element holding hole 5a is formed and a first open end face 3a in which a second element holding hole 5b is formed.
- the first open end face 3a and the second open end face 3b are formed in parallel with the direction of current flow in the electric wire P to be measured.
- the first element holding hole 5a is formed in the first open end face 3a in parallel with the thickness direction of the magnetic core 1 (current flow direction of the electric wire P to be measured).
- the second element holding hole 5b is formed in the second open end surface 3b in parallel with the thickness direction of the magnetic core 1.
- the first element holding hole 5a and the second element holding hole 5b are formed in a rectangular groove shape and at positions facing each other.
- the first element holding hole 5a and the second element holding hole 5b hold a magnetoelectric conversion element that converts the magnetic flux generated by the magnetic core 1 into an electric signal.
- the gap between the first open end surface 3a and the second open end surface 3b is referred to as “magnetic flux leakage portion 3”. Further, when the first element holding hole 5a and the second element holding hole 5b are not distinguished from each other, they are simply referred to as “element holding holes 5”.
- FIG. 2 is a diagram for explaining another embodiment of the magnetic core 1.
- the element holding hole 5 is formed in a direction perpendicular to the thickness direction of the magnetic core 1.
- the element holding hole 5 may be formed in an oblique direction instead of a direction parallel to and perpendicular to the thickness direction of the magnetic core 1.
- FIG. 3 is a view for explaining still another embodiment of the magnetic core 1.
- FIG. 3 (a) shows a first modification of the element holding hole 5 of FIG. () Is a figure which shows the 2nd modification of the element holding hole 5 of FIG. 1, respectively.
- the element holding hole 5 in FIG. 3A is realized with a configuration in which the lower side (lower side in the drawing) of the element holding hole 5 in FIG. 1 does not exist.
- the element holding hole 5 in FIG. 3B is realized by a configuration in which the upper side (upper side in the drawing) and the lower side (lower side in the drawing) of the element holding hole 5 in FIG. Has been. Even a magnetic core realized with such a configuration can achieve the effects described below, and thus is included in the category of the present embodiment.
- FIGS. 4A and 4B are diagrams for explaining a method of forming the magnetic core 1.
- FIG. 4A is a top view of the magnetic core 1
- FIG. 5 is a cross-sectional view taken along the line AA ′ in FIG.
- the magnetic core 1 may be formed of a single layer or may be formed by laminating a plurality of layers.
- FIG. 5A and 5B are diagrams for explaining a method of forming the magnetic core 1.
- FIG. 5A shows an integrated magnetic core
- FIG. 5B shows a docking magnetic core
- FIG. ) Is a diagram for explaining another docking type magnetic core.
- the magnetic core 1 can be realized in various types.
- FIG. 6A and 6B are diagrams for explaining the shape of the magnetic core 1.
- FIG. 6A is a diagram for explaining an annular magnetic core
- FIG. 6B is a diagram for explaining a quadrangular magnetic core.
- the magnetic core 1 can be realized in various shapes.
- the magnetic core 1 can be realized in various structures and shapes.
- the annular magnetic core described with reference to FIG. is there.
- the magnetic core 1 may be realized by the following configuration.
- the first open end surface 3a and the second open end surface 3b are described as being held in parallel and the both end surfaces are not in contact with each other (hereinafter, this structure is referred to as “gap structure”). Sometimes called). However, the first open end surface 3a and the second open end surface 3b may be partially in contact with each other (hereinafter, this configuration may be referred to as “abutting structure”). This is because the first open end surface 3a and the second open end surface 3b are not completely parallel, and part of the first open end surface 3a and the second open end surface 3b. This is because they may contact each other.
- the magnetic core 1 having an abutting structure is also included in the category of the present embodiment because the same effects as the gap structure (details will be described later) are obtained. [2. Various measurement results for magnetic core 1] Next, various measurement results regarding the magnetic core 1 will be described.
- FIG. 7 is a diagram showing a measurement result of magnetic flux density using a known magnetic core and the magnetic core 1
- FIG. 7A shows a measurement result using the known magnetic core of FIG. (B) of the figure shows the measurement results using the known magnetic core of FIG. 17 (b)
- (c) of FIG. 17 shows the magnetic core of (b) of FIG.
- the measurement results by the magnetic core provided with are respectively shown.
- the x mark shown in each figure shows the measurement point of magnetic flux density.
- the measurement conditions using the magnetic core shown in each figure are the same, such as the size of the magnetic core or the current value (30 mA) flowing through the wire to be measured, except for the characteristic magnetic core shape.
- the width of the cut portion provided in the magnetic core of FIG. 8A and the notch portion provided in the magnetic core of FIG. 10B and FIG. Is the same as the width of the element holding hole 5 provided in the magnetic core shown in FIGS.
- the measurement results with the magnetic core in each figure are 0.018 mT for the magnetic core in (a) in the figure, 0.0015 mT for the magnetic core in (b) in the figure, (
- the magnetic core in c) was 0.046 mT
- the magnetic core in (d) in the figure was 0.073 mT
- the magnetic core in (e) in the figure was 0.073 mT. That is, the magnetic core 1 shown in FIGS. 4D and 4E is about four times as large as the magnetic core shown in FIG. 5A and about 48 times the magnetic core shown in FIG.
- the measurement sensitivity is about 1.6 times that of the magnetic core of (c). This also shows that the magnetic core 1 has significantly improved sensitivity for measuring the magnetic flux density compared to the known magnetic core.
- FIG. 8 is a diagram for explaining that the measurement sensitivity of the magnetic flux density is improved by the magnetic core 1, and is a diagram showing the positional relationship of the magnetoelectric conversion element 20 with respect to the magnetic flux leakage portion 3.
- an element holding hole 5 is provided in a direction perpendicular to the thickness direction of the magnetic core 1, and a magnetoelectric conversion element 20 is held in the element holding hole 5.
- the magnetoelectric conversion element 20 mainly includes a substrate 22, a sensor film 24, a wire bonding 26, and a molding agent 28.
- a sensor film 24 is disposed on the plate-like substrate 22, and the substrate 22 and the sensor film 24 are fixed by wire bonding 26.
- the substrate 22, the sensor film 24, and the wire bonding 26 are covered with a molding agent 28.
- the magnetoelectric conversion element 20 is held in the element holding hole 5 so as to cross the magnetic flux leakage portion 3.
- the positional relationship of the magnetoelectric conversion element 20 with respect to the magnetic flux leakage part 3 is determined as described above. Therefore, the magnetic flux easily leaks from the magnetic core 1 to the element holding hole 5 via the magnetic flux leakage portion 3, and the magnetoelectric conversion element 20 held in the element holding hole 5 is arranged in the vertical direction (the thickness of the magnetic core 1. Magnetic flux leakage from (direction) can be detected.
- the sensitivity of the magnetic core is better when the magnetic resistance of the magnetic flux leakage portion 3 is lower to some extent.
- the magnetic resistance of the magnetic flux leaking part 3 falls as the width of the magnetic flux leaking part 3 (distance between the first open end face 3a and the second open end face 3b) is narrower.
- the magnetoelectric conversion element 20 is held in the first element holding hole 5a and the second element holding hole 5b formed in the first open end face 3a and the second open end face 3b. Therefore, the distance between the first open end surface 3a and the second open end surface 3b does not need to be wide enough to provide the magnetoelectric conversion element 20 therein.
- the distance between the first open end surface 3a and the second open end surface 3b can be reduced without considering the size of the magnetoelectric transducer 20. Accordingly, in the magnetic core 1, the width of the magnetic flux leakage portion 3 is narrow, and therefore the magnetic resistance of the magnetic flux leakage portion 3 is also reduced.
- the magnetic core 1 can remarkably improve the measurement sensitivity of the magnetic flux density compared to a known magnetic core.
- the magnetic resistance difference is large becomes too between the magnetic core and the element holding hole (10 4 times), it is hardly flux leakage in the element holding hole, magnetoelectric The conversion element does not sense magnetic flux.
- the magnetoelectric conversion element 20 uses an MR (magneto-resistive) element such as GMR (Giant-Magneto-Resistance) and AMR (Anisotropic-Magnetoresistive), or an MI (magneto-impedance) element, a flux gate element, a Hall element, or the like. be able to.
- MR magnetic-resistive
- GMR Global Magnetic Resistance
- AMR Magnetic-Magnetoresistive
- MI magneticto-impedance
- the element holding hole 5 is provided in a direction perpendicular to the thickness direction of the magnetic core 1.
- the element holding hole 5 is provided in a direction perpendicular to the width direction of the magnetic core 1 (direction perpendicular to the thickness direction of the magnetic core 1), and the magnetoelectric conversion element 20 is held in the element holding hole 5. Even if it is, it can have an effect similar to the above.
- FIG. 9 is a diagram showing the measurement results of the magnetic flux density using the magnetic core 1.
- FIG. 9A is a diagram for illustrating the definition of each symbol
- FIG. (C) of the figure is a graph showing the magnetic flux density when L1 is changed.
- W represents the width of the magnetic flux leakage portion 3 (the distance between the first open end face 3a and the second open end face 3b).
- L1 is a side surface (first side surface) 16 that faces the side surface that forms the second element holding hole 5b among the side surfaces that form the first element holding hole 5a, and the side surface that forms the second element holding hole 5b.
- first side surface the side surface that forms the second element holding hole 5b
- second side surface 17 the distance between the side surface 16 and the side surface 17 when the side surface facing the side surface 16 is the side surface (second side surface) 17 is represented.
- L2 represents the distance between the side surface 18a and the side surface 18b when the side surface excluding the side surface 16 among the side surfaces forming the first element holding hole 5a is the side surface 18a and the side surface 18b. Note that L2 is also the distance between the side surface 19a and the side surface 19b when the side surface excluding the side surface 17 among the side surfaces forming the second element holding hole 5b is the side surface 19a and the side surface 19b.
- the first element holding hole 5 a and the second element holding hole 5 b hold the magnetoelectric conversion element 20 such that the magnetosensitive direction of the magnetoelectric conversion element 20 is the circumferential direction of the magnetic core 1.
- the magnetoelectric conversion element 20 having a small size in the thickness direction of the magnetoelectric conversion element 20 can be matched with the direction from the side surface 18a to the side surface 18b corresponding to the vertical direction of the drawing (or the direction from the side surface 19a to the side surface 19b). And thereby L2 can be reduced.
- the thickness direction of the magnetoelectric conversion element 20 is shorter than the longitudinal direction. Therefore, L2 can be reduced by adjusting the thickness direction to the direction from the side surface 18a to the side surface 18b corresponding to the vertical direction of the drawing (or the direction from the side surface 19a to the side surface 19b). As a result, the measurement sensitivity of the magnetic core 1 can be improved.
- the measurement sensitivity of the current sensor using the magnetic core 1 can be improved by reducing W.
- the first element holding hole 5a and the second element holding hole 5b are configured so that the magnetoelectric conversion element 20 and the magnetosensitive direction of the magnetoelectric conversion element 20 are the circumferential direction of the magnetic core 1. It can be said that it is preferable to hold in this way.
- the magnetic core 1 may have an abutting structure for manufacturing and processing reasons. Even in such a case, the magnetic core 1 has the same effect as the gap structure. This will be described with reference to FIG.
- FIG. 10A and 10B are views showing the magnetic core 1 having a gap structure, where FIG. 10A shows the magnetic core 1 having the gap structure, and FIG. 10B shows the first open end face 3a and the second open end.
- the magnetic core 1 having an abutting structure in which the end surface 3b is in contact at two locations is shown in FIG. 5C, in which the first open end surface 3a and the second open end surface 3b are in contact at 16 locations. It is a figure which shows the magnetic core 1, respectively.
- variety of the magnetic flux leakage part 3 is maintained at 30 micrometers in any magnetic core 1.
- a point where the first open end face 3a and the second open end face 3b are in contact with each other is defined as a contact point 7.
- the contact area of the contact point 7 is set to 3 ⁇ m 2 which is sufficiently smaller than the cross-sectional area of the first open end face 3a or the second open end face 3b. This is due to the fact that the contact area of the contact point 7 is sufficiently smaller than the cross-sectional area of the first open end surface 3a or the second open end surface 3b when the magnetic core having the butting structure is actually manufactured and processed. It is reflected.
- the measurement results of the magnetic flux density by the magnetic core 1 in each figure were all 2.5 mT. From this, it can be said that the magnetic core 1 has no change in measurement sensitivity even if it has a gap structure. Therefore, when it is difficult to manufacture and process the first open end surface 3a and the second open end surface 3b without contacting them, the gap structure can be used. As a result, it is possible to realize the magnetic core 1 capable of increasing the detection sensitivity of the current sensor, to eliminate an additional manufacturing / processing step, and to reduce the price.
- FIG. 11 is a diagram showing the measurement results of the magnetic flux density using the magnetic core 1.
- FIG. 11A is a diagram for showing the definition of each symbol
- FIG. (C) in the figure shows the magnetic flux density when L1 is 1.5 mm
- (d) in the figure shows the magnetic flux density when L1 is 2 mm. It is a graph.
- FIG. 11 is a graph of the following Table 1.
- FIG. 12 is a diagram for explaining that the measurement sensitivity of the magnetic flux density by the magnetic core 1 is affected by the presence or absence of a magnetic agent (low magnetic permeability material).
- FIG. 3 and the element holding hole 5, a case where the magnetic agent is not encapsulated
- (b) of the figure shows a case where the magnetic agent is encapsulated only in the magnetic flux leakage portion 3
- FIG. Shows a case in which the magnetic agent is sealed only in the element holding hole 5
- (d) in FIG. 9 shows a case in which the magnetic agent is sealed in both the magnetic flux leakage portion 3 and the element holding hole 5, respectively.
- FIG. 3 and the element holding hole 5 a case where the magnetic agent is not encapsulated
- (b) of the figure shows a case where the magnetic agent is encapsulated only in the magnetic flux leakage portion 3
- FIG. Shows a case in which the magnetic agent is sealed only in the element holding hole 5
- (d) in FIG. 9 shows a case in which the magnetic agent is
- the magnetic agent is a material having a relative permeability of 20 and a lower relative permeability than the main body of the magnetic core 1. Moreover, the x mark shown in each figure shows the measurement point of magnetic flux density.
- the measurement results of the magnetic flux density by the magnetic core in each figure are 2.44 mT for the magnetic core 1 in FIG. 5A and 2.90 mT for the magnetic core 1 in FIG. It was 48.68 mT in the magnetic core 1 of (c) of the same figure, and 48.14 mT in the magnetic core 1 of (d) of the same figure. From this, it was found that the measurement sensitivity of the magnetic flux density was remarkably improved by encapsulating the magnetic agent in the element holding hole 5 in particular. It was also found that when a magnetic agent was sealed in the element holding hole 5, the sensitivity was improved at the same magnification as the relative permeability of the magnetic agent.
- the magnetic resistance of the magnetic flux leakage portion 3 is reduced.
- the sensitivity of the magnetic core 1 is improved.
- a magnetic agent (substance)
- a ferrite containing epoxy resin a magnetic fluid, air, etc.
- a magnetic fluid a magnetic fluid, air, etc.
- FIG. 13 is a diagram showing measurement results of noise resistance using a known magnetic core and magnetic core 1
- FIG. 13 (a) is a measurement result using the known magnetic core of FIG. 17 (a).
- (B) of the figure shows the measurement results using the known magnetic core of FIG. 17 (b)
- (c) of FIG. 17 shows the magnetic core of (b) of FIG.
- the measurement results with the magnetic core provided with are shown, and (d) in the figure shows the measurement results with the magnetic core 1.
- P represents the wire to be measured
- Q represents the external wire
- the distance between P and Q is 20 mm.
- a current of 30 mA is passed through the measured electric wire P, and the magnetic flux density at that time is measured.
- a current of 20 A is passed through the external wire Q while a current of 30 mA is passed through the wire to be measured P, and the magnetic flux density at that time is measured. Then, how much measurement error occurs in the two measured magnetic flux densities is calculated. The smaller the measurement error, the higher the noise tolerance, and the larger the error, the lower the noise tolerance.
- the measurement error due to the magnetic core in each figure is 11.3% for the magnetic core in (a) in the figure, 52% in the magnetic core in (b) in the figure, and ( The magnetic core of c) was 73%, and the magnetic core of (d) in the figure was 8.4%.
- the magnetic core 1 has higher noise resistance than known magnetic cores. The reason will be described with reference to FIG. FIG. 14 is a diagram for explaining that the noise tolerance of the magnetic core 1 is high.
- the conventional current sensor has no noise resistance in the magnetic core itself, there is a problem that a value to be detected is buried in noise due to the influence of an external magnetic field when measuring a current of several tens of mA.
- the magnetic flux leakage portion 3 surrounded by a broken line in the figure serves as a shield against an external magnetic field generated by geomagnetism or an external current. It is considered that the influence of the held magnetoelectric conversion element 20 from the external magnetic field is reduced.
- FIG. 15 is a graph showing the relationship between the magnetic core thickness and the measurement error.
- the horizontal axis indicates the magnetic core thickness (mm), and the vertical axis indicates the measurement error (%). Note that the measurement conditions are the same as those described with reference to FIG.
- the measurement error decreases as the magnetic core is thicker. That is, the thicker the magnetic core, the better the noise resistance. This is due to the fact that the thicker the magnetic core, the larger the magnetic flux leakage portion 3 and the greater the shielding effect of the magnetic flux leakage portion 3. Therefore, by appropriately adjusting the thickness of the magnetic core, it is possible to simultaneously reduce the size of the current sensor and improve the measurement accuracy. [3. Effects obtained by the magnetic core 1] Hereinafter, effects obtained by the magnetic core 1 will be described.
- the magnetic core 1 is a magnetic core used for a current sensor, and is a first in which a first element holding hole 5a for holding a magnetoelectric conversion element 20 is formed. It is characterized by having an open end face 3a and a second open end face 3b facing the first open end face 3a in which a second element holding hole 5b for holding the magnetoelectric conversion element 20 is formed.
- the magnetic core 1 has a first open end surface 3a and a second open end surface 3b facing each other.
- a first element holding hole 5a is formed in the first open end face 3a
- a second element holding hole 5b is formed in the second open end face 3b
- the first element holding hole 5a and the second element holding hole 5b are formed.
- the magnetoelectric conversion element 20 is held.
- the magnetic flux from the magnetic core 1 is likely to leak to the first element holding hole 5a and the second element holding hole 5b via the magnetic flux leakage portion 3, and the first element holding hole
- the magnetoelectric transducer 20 held in 5a and the second element holding hole 5b can sense the leakage of the magnetic flux.
- the sensitivity of the magnetic core 1 is better when the magnetic resistance of the magnetic flux leakage portion 3 is lower, but the width of the magnetic flux leakage portion 3 (distance between the first open end surface 3a and the second open end surface 3b) is narrow. On the other hand, the magnetic resistance of the magnetic flux leakage portion 3 is lowered.
- the magnetoelectric conversion element 20 is held in the first element holding hole 5a and the second element holding hole 5b formed in the first open end face 3a and the second open end face 3b. Therefore, the distance between the first open end face 3a and the second open end face 3b does not need to be so large that the magnetoelectric conversion element 20 is placed between them.
- the distance between the first open end face 3a and the second open end face 3b can be reduced without considering the mounting space of the magnetoelectric conversion element 20. Therefore, in the magnetic core 1, the width of the magnetic flux leakage portion 3 is narrow, and hence the magnetic resistance of the magnetic flux leakage portion 3 is also reduced, so that the sensitivity of the current sensor using the magnetic core 1 can be improved.
- the magnetic core 1 has the conventional problem described with reference to FIG. 17A (the magnetoelectric conversion element 20 is provided in the cut portion, and therefore the width of the cut portion must be widened, Accordingly, the problem that the sensitivity of the magnetic core 1 is reduced can be solved.
- the first element holding hole 5 a and the second element holding hole 5 b are not positioned along the outer edge of the magnetic core 1 where the magnetic flux hardly leaks from the magnetic core 1, but the first open end face 3 a and the second element holding hole 5 b. It is formed on the open end surface 3b.
- the magnetoelectric conversion element 20 is held in the first element holding hole 5 a and the second element holding hole 5 b where magnetic flux easily leaks from the magnetic core 1, and is generated by a minute current. More magnetic flux to be collected can be collected in the magnetoelectric conversion element to improve the sensitivity.
- the magnetic core 1 has a conventional problem described with reference to FIG. 17B (the magnetic core 1 is placed on the notch formed along the outer edge of the magnetic core, and the magnetic core 1 has a magnetic flux. Is difficult to leak, and the magnetic flux detected by the magnetoelectric transducer 20 becomes very small, thereby reducing the sensitivity of the magnetic core.
- the magnetic core 1 can realize a magnetic core capable of enhancing the detection sensitivity of the current sensor depending on the configuration.
- the magnetic core 1 has the following effects.
- the conventional current sensor does not have a structure (function) that realizes noise immunity in the magnetic core itself. Therefore, when measuring a current of several tens of mA, it is affected by an external magnetic field, and the current can be measured with high detection sensitivity. could not.
- the magnetic flux leakage portion 3 serves as a shield against an external magnetic field generated by geomagnetism or an external current. Therefore, the magnetic core 1 can also solve the conventional problem that miniaturization and cost reduction are hindered by covering the magnetic core with a shield material.
- the magnetoelectric conversion element 20 in the magnetic core 1, in the first element holding hole 5a and the second element holding hole 5b, the magnetoelectric conversion element 20 is connected to the magnetoelectric conversion.
- the element 20 may be configured to be held such that the magnetic sensing direction of the element 20 is the circumferential direction of the magnetic core 1.
- the magnetoelectric conversion element 20 having a small size in the thickness direction of the magnetoelectric conversion element 20 (the thickness direction of the magnetic core 1 perpendicular to the circumferential direction of the magnetic core 1) can be selected.
- the width in the thickness direction of the magnetic core of the first element holding hole 5a and the second element holding hole 5b holding the conversion element 20 can be reduced.
- the magnetic flux which leaks from the magnetic core 1 is amplified, so that the width
- the first element holding hole 5a and the second element holding hole 5b are filled with a low magnetic permeability material having a lower magnetic permeability than the magnetic core 1. It may be.
- the sensitivity can be improved at the same magnification as the relative magnetic permeability of the low magnetic permeability material.
- a low magnetic permeability material having a lower magnetic permeability than that of the magnetic core 1 is filled between the first open end face 3a and the second open end face 3b. It may be a configuration.
- the low permeability material may be a ferrite-containing epoxy resin, a magnetic fluid, or air.
- PB permalloy, PC permalloy, amorphous, silicon steel plate and the like are known. Any material can be used for the magnetic core 1.
- ferrite-containing epoxy resin, magnetic fluid, or air can be cited as a low-permeability material having a lower magnetic permeability than such a magnetic core.
- a magnetic core capable of further increasing the detection sensitivity of the current sensor is realized by filling the first element holding hole 5a and the second element holding hole 5b with a ferrite-containing epoxy resin, a magnetic fluid, or air. be able to.
- the side face that faces the side face that forms the second element holding hole 5b among the side faces that form the first element holding hole 5a is the first side face
- the second element Of the side surfaces forming the holding hole 5b when the side surface facing the first side surface is the second side surface, the first element holding hole 5a and the second element holding hole 5b are in the thickness direction of the magnetoelectric conversion element 20 to be held. Is preferably 1.75 times or less the distance between the side surfaces of the first side surface and the second side surface.
- the above configuration produces an effect that a large amount of magnetic flux can be collected in the magnetoelectric conversion element 20 even by a minute current.
- the distance between the first open end face 3a and the second open end face 3b is preferably smaller than 2 mm.
- the magnetoelectric conversion element 20 is held in the first element holding hole 5a and the second element holding hole 5b.
- the magnetoelectric conversion element 20 has an effect that the magnetic flux leaking from the magnetic core 1 can be reliably detected with respect to the first element holding hole 5a and the second element holding hole 5b.
- the first open end surface 3a and the second open end surface 3b may be configured such that parts thereof are in contact with each other.
- magnetic core 1 can be applied to any type.
- any type of magnetic core it may be actually difficult to manufacture and process the first open end surface 3a and the second open end surface 3b without contacting them at all.
- the magnetoelectric transducer 20 can detect the leakage of the magnetic flux. Therefore, when it is difficult to manufacture and process the first open end surface 3a and the second open end surface 3b without contacting them, they can be used as they are. As a result, it is possible to realize a magnetic core capable of increasing the detection sensitivity of the current sensor, eliminate the need for an additional manufacturing / processing step, and reduce the price.
- the first element holding hole 5a and the second element holding hole 5b are respectively along the direction parallel to the thickness direction of the magnetic core 1 on the first open end face 3a and the second open end face 3b.
- the structure may be extended.
- the first element holding hole 5a and the second element holding hole 5b are respectively in the thickness direction of the magnetic core 1 at the first open end face 3a and the second open end face 3b. It may be configured to extend along a direction perpendicular to the direction.
- various types such as an integral type, a laminated type, and a docking type are known as general magnetic core structures.
- the magnetic core 1 when a laminated magnetic core is manufactured, a plurality of layers in which the first element holding hole 5a and the second element holding hole 5b are formed at the same location are prepared, and the layers are sequentially laminated, whereby the magnetic core 1 can be produced easily and at low cost. Even when the magnetic core 1 is manufactured as an integral type or a docking type, the magnetic core 1 can be manufactured easily and at low cost by adopting the above configuration. Thereby, the magnetic core 1 suitable for mass production can be realized.
- the current sensor according to the present invention preferably has a configuration including a magnetic core 1.
- the current measuring method it is preferable to measure the current value of the current flowing through the measured wire by a current sensor including the magnetic core 1.
- the current sensor provided with the magnetic core 1 can be applied to various applications, for example, detection of electric leakage of power conditioners such as solar cells and fuel cells, battery monitoring mounted on a hybrid car, a plug-in hybrid car, etc. Alternatively, it can be used in a wide range of fields such as battery monitoring of a data center UPS.
- FIG. 16 is a diagram when the current sensor provided with the magnetic core 1 is used for detecting leakage in the solar cell power conditioner.
- the alternating current output from the solar panel is rectified by a converter and converted to direct current by an inverter.
- the magnetic core 1 amplifies the magnetic field which generate
- the current in the above two wires under measurement corresponds to the going and returning current, and the total current value is 0A. Therefore, when a leakage occurs, the total current value does not become 0A. Therefore, the current sensor including the magnetic core 1 can detect the presence or absence of leakage by measuring the total current value.
- the earth leakage sensor provided with the magnetic core 1 measures current values of 30 mA, 50 mA, 100 mA, and 150 mA determined by international standards.
- the magnetic core 1 can naturally measure various current values.
- the magnetic core 1 is used for detecting leakage of the solar cell power conditioner has been described as one application example.
- the embodiment described here is merely an application example and is not limited to its use.
- [5. Current sensor with magnetic core] Next, the current sensor 30 including the magnetic core 1 will be described with reference to FIGS. The description of the contents described with reference to FIG. 1 and the like is omitted.
- FIG. 18 is an external view of the current sensor 30.
- the external appearance of the current sensor 30 is formed by a case 31.
- the case 31 is provided with a through hole in the vertical direction in the figure, and the wire to be measured P is disposed in the through hole.
- the current sensor 30 measures the current value of the current flowing through the measured wire P by detecting a magnetic field generated from the current of the measured wire P.
- FIG. 19 is a perspective view of the internal structure of the current sensor 30.
- 20 is a cross-sectional view of the internal structure of the current sensor 30 in the horizontal direction (left-right direction in the figure) in FIG.
- FIG. 21 is an exploded view of the current sensor 30.
- the current sensor 30 includes a magnetic core 1 a and 1 b, a magnetic flux leakage portion 3, an element holding hole 5, a magnetoelectric transducer 20, an output signal processing circuit 32, and a case 31. Fasteners 33a and 33b are provided.
- the current sensor 30 is electrically connected to an external device via the input / output terminal 33.
- case 31a and case 31b are engaged with each other.
- case 31a serves as an outer case
- case 31b serves as an inner case. Fulfill. That is, the case 31a forms the appearance of the current sensor 30, and the case 31b forms the wall surface of the through hole on which the measured electric wire P is arranged.
- the magnetic cores 1a and 1b, the magnetic flux leakage portion 3, the element holding hole 5, the magnetoelectric transducer 20, and the output signal processing circuit 32 The fasteners 33a and 33b are disposed.
- the magnetic core 1 is a dockable type that is composed of a magnetic core 1a and a magnetic core 1b and can be divided into two (details are described with reference to FIG. 25 and the like).
- the magnetic cores 1a and 1b are held in a square shape by being inserted into the fasteners 33a and 33b.
- the magnetic core 1 is formed with the magnetic flux leakage portion 3 and the element holding hole 5 on the fastener 33a side, and the magnetic cores 1a and 1b are in close contact with each other on the fastener 33b side. This is illustrated in FIG.
- the fastener 33a functions as a fastener for the magnetic core 1a and the magnetic core 1b, and is connected and supported by the plate-like output signal processing circuit 32.
- the output signal processing circuit 32 is electrically connected to the input / output terminal 33, processes the voltage output from the magnetoelectric conversion element 20, and outputs the voltage corresponding to the current value of the measured wire P to the input / output terminal.
- the data is output to an external device via 33.
- the output signal processing circuit 32 is provided with a T-shaped small substrate, and the magnetoelectric transducer 20 is fixed to the small substrate.
- the magnetoelectric conversion element 20 is positioned so as to be held in the element holding hole 5. That is, in the current sensor 30 in FIGS. 19 to 21, the magnetoelectric conversion element 20 is fixed to the output signal processing circuit 32, and is in a non-contact state with the element holding hole 5, while remaining in the element holding hole 5. Is retained.
- the magnetoelectric conversion element 20 may be held in the element holding hole 5 while maintaining a state in contact with the element holding hole 5. Therefore, the magnetoelectric conversion element 20 is realized by a configuration in which the magnetoelectric conversion element 20 is held in the element holding hole 5 while maintaining a contact and / or non-contact state with the element holding hole 5.
- the method for holding and fixing the magnetoelectric conversion element is not limited to the embodiment described here.
- FIG. 22 is a block diagram for explaining the operation of the current sensor 30.
- a current I flows in the measured wire P, and a magnetic field H is generated by the current I.
- the magnetic field H generates a magnetic flux ⁇ in the magnetic core 1.
- the magnetic flux ⁇ generated in the magnetic core 1 leaks into the magnetic flux leakage portion 3.
- the magnetic flux ⁇ H is detected by the magnetoelectric conversion element 20.
- Electric transducer 20 converts the detected magnetic flux [Phi H in voltage, and outputs a voltage V M which is the converted output signal processing circuit 32.
- the output signal processing circuit 32 processes the voltage V M, and outputs the output terminal 33 a voltage (V 0) corresponding to the current value flowing to the measured wire P.
- the current sensor 30 measures the current flowing through the measured electric wire P.
- the current sensor 30 can measure the current value I of the current flowing in the measured wire P.
- the current sensor 30 can be used not only for measuring a current value but also for detecting a leakage current and measuring a leakage amount, for example. This will be described with reference to FIGS.
- FIG. 23 is an external view of a current sensor used for detecting leakage and measuring the amount of leakage.
- the wires to be measured P1 and P2 are arranged in the through holes provided in the current sensor 30.
- the currents in the two wires to be measured P1 and P2 correspond to the going and returning currents, and if there is no leakage, the total current value is 0A. In other words, the total current value does not become 0 A when leakage occurs.
- the current sensor 30 detects the presence / absence of electric leakage and the amount of electric leakage when there is electric leakage.
- FIG. 24 is a block diagram for explaining the operation of the current sensor when the current sensor is used for leakage detection. The operation of the current sensor when the current sensor is used for leakage detection will be described with reference to FIG.
- the current I 0 flows in the measured wire 1 (P1), current in the measuring wire 2 (P2) - (I 0 -I L) flows case, i.e., current I L is leakage Think of a case.
- a current I 0 flows in the measured wire P1
- a magnetic field H 0 is generated by the current I 0 .
- a current ⁇ (I 0 ⁇ I L ) flows in the measured electric wire P2, and a magnetic field ( ⁇ H 0 + H L ) is generated by the current ⁇ (I 0 ⁇ I L ).
- the magnetic field H 0 and ( ⁇ H 0 + H L ) generate a magnetic flux ⁇ L in the magnetic core 1.
- the magnetic flux ⁇ L represents the amount of magnetic flux generated by the sum of the input magnetic fields to the magnetic core 1.
- the magnetic flux ⁇ L generated in the magnetic core 1 leaks into the magnetic flux leakage portion 3.
- the magnetic flux ⁇ HL is detected by the magnetoelectric conversion element 20.
- the magnetoelectric conversion element 20 converts the detected magnetic flux ⁇ HL into a voltage, and outputs the converted voltage V ML to the output signal processing circuit 32.
- the output signal processing circuit 32 processes the voltage V ML and outputs a voltage (V 0L ) corresponding to the current value of the leaked current to the input / output terminal 33.
- the current sensor 30 measures leakage detection and the amount of leakage.
- various shapes of the magnetic core will be described with reference to FIGS. However, the shape of the magnetic core described here is merely an example, and is not limited thereto.
- FIG. 25 shows one shape of the magnetic core
- FIG. 25A shows a top view
- FIG. 25B shows a front view
- 26 shows the magnetic core 40 of FIG. 25
- FIG. 26 (a) is a perspective view
- FIG. 26 (b) is an enlarged view of the magnetic flux leakage portion 3 and the element holding hole 5.
- the magnetic core 40 has a rectangular shape when viewed from above, and a rectangular shape when viewed from the front.
- the magnetic core 40 is a single-layer type in which a U-shaped first core portion 40a and a second core portion 40b are docked.
- the first core portion 40a and the second core portion 40b are in close contact with each other on a surface (a surface on the upper side of FIG. 25A) constituting one surface of a quadrilateral shape.
- the first core portion 40a and the second core portion 40b form the magnetic flux leakage portion 3 and the element holding hole 5 on the surface facing the surface (the surface on the lower side of FIG. 25A). Yes.
- the element holding hole 5 is formed by a first element holding hole provided in the first open end face and a second element holding hole provided in the second open end face.
- the element holding hole 5 is formed in a radial direction with respect to a current flowing through a measured electric wire (not shown), and penetrates the first core portion 40a and the second core portion 40b (FIG. 26). .
- FIG. 27 shows one shape of the magnetic core
- FIG. 27 (a) is a top view
- FIG. 27 (b) is a perspective view.
- the magnetic core 41 is a single-layer integrated type that has a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in parallel to the current flowing through the wire to be measured (not shown), and penetrates the first core portion 41a and the second core portion 41b. Further, the first open end surface and the second open end surface are spaced apart and are not in contact with each other.
- the element holding hole may be formed in either a radial direction or a parallel direction with respect to a current flowing through the measurement target electric wire (not shown).
- the thickness of the magnetic core may be thick or thin.
- the shape of the magnetic core is not limited to a specific shape, and can be various shapes. Therefore, the shape of the magnetic core can be appropriately changed according to the design of the device, the layout inside the current sensor, and the like.
- FIG. 28 to FIG. 30 are diagrams showing a state in which the existence range of the element holding hole in the magnetic core is different when the shape of the magnetic core is the same. Hereinafter, description will be made sequentially from FIG.
- FIG. 28 shows one shape of the magnetic core
- FIG. 28 (a) is an elevation view
- FIG. 28 (b) is a top view
- FIG. 28 (c) is a perspective view.
- the magnetic core 42 is formed of a single-layer integrated type having a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in a radial direction with respect to a current flowing through a measured electric wire (not shown) and penetrates the magnetic core 42.
- the hatched area in FIG. 28B indicates the magnetic core, and the other area indicates the element holding hole 5.
- FIG. 29 and subsequent figures As shown in the figure, the first open end face and the second open end face are separated and are not in contact with each other.
- FIG. 29 shows one shape of the magnetic core
- FIG. 29 (a) is an elevation view
- FIG. 29 (b) is a top view
- FIG. 29 (c) is a perspective view.
- the magnetic core 43 is different from the magnetic core 42 of FIG. 28 in the following points. That is, the element holding hole 5 is closed on the side of the measured wire (not shown) without penetrating the magnetic core 42 and is open on the side opposite to the measured wire. That is, the element holding hole 5 is open only on one side in the radial direction with respect to the current flowing through the wire to be measured.
- FIG. 30 shows one shape of the magnetic core
- FIG. 30 (a) is an elevation view
- FIG. 30 (b) is a top view
- FIG. 30 (c) is a perspective view.
- the magnetic core 44 is different from the magnetic core 43 of FIG. 29 in the following points. That is, the element holding hole 5 is closed on both sides in the radial direction with respect to the current flowing through the wire to be measured. Therefore, the element holding hole 5 is confined inside the magnetic core 44 and communicates with the outside only through the magnetic flux leakage portion 3.
- FIG. 31 shows one shape of the magnetic core
- FIG. 31 (a) is a top view
- FIG. 31 (b) is an elevation view.
- the magnetic core 45 is configured as a single-layer integrated type having a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in parallel to the current flowing through the wire to be measured (not shown) and penetrates the magnetic core 42. Note that the first open end face and the second open end face are spaced apart and are not in contact with each other.
- FIG. 32 shows one shape of the magnetic core
- FIG. 32A shows a top view
- FIG. 32B shows an elevation view.
- the magnetic core 46 is different from the magnetic core 45 of FIG. 31 in the following points. That is, the element holding hole 5 does not penetrate the magnetic core 46, and the lower side of FIG. 32B is closed, and the upper side of FIG. 32B is open. That is, the element holding hole 5 is open only on one side in a direction parallel to the current flowing through the wire to be measured.
- FIG. 33 shows one shape of the magnetic core 47, FIG. 33 (a) is a top view, and FIG. 33 (b) is an elevation view.
- the magnetic core 47 is different from the magnetic core 46 of FIG. 32 in the following points. That is, the element holding hole 5 is closed on both the upper and lower sides in the direction parallel to the current flowing through the wire to be measured. Therefore, the element holding hole 5 is confined inside the magnetic core 47 and communicates with the outside via the magnetic flux leakage portion 3.
- FIG. 34 shows one shape of the magnetic core
- FIG. 34 (a) is a perspective view
- FIG. 34 (b) is a top view.
- the magnetic core 48 is formed of a single-layer integrated type having a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in a radial direction with respect to a current flowing through a measurement target electric wire (not shown) and penetrates the magnetic core 48. Note that the first open end face and the second open end face are spaced apart and are not in contact with each other.
- FIG. 35 shows one shape of the magnetic core
- FIG. 35 (a) is a perspective view
- FIG. 35 (b) is a top view.
- the magnetic core 49 is different from the magnetic core 48 of FIG. 34 in the following points. That is, the magnetic core 49 has a quadrangular shape when viewed from above, but is configured in a stacked type. More specifically, the magnetic core 49 is formed by laminating a magnetic core 49a, a magnetic core 49b, a magnetic core 49c, and a magnetic core 49d in that order in the direction of a measured electric wire (not shown).
- the magnetic core 49 can be realized not only by a single layer integrated type but also by a laminated type.
- the magnetic core 49 has a four-layer structure including the magnetic core 49a to the magnetic core 49d, but may have a structure of two layers, three layers, or five layers or more.
- the magnetic core is a single layer type or a laminated type
- FIG. 36 shows one shape of the magnetic core
- FIG. 36 (a) is a top view
- FIG. 36 (b) is an elevation view.
- the magnetic core 50 is configured as a single-layer integrated type having a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in parallel to the current flowing through the wire to be measured (not shown) and penetrates the magnetic core 50. Note that the first open end face and the second open end face are spaced apart and are not in contact with each other.
- FIG. 37 shows one shape of the magnetic core
- FIG. 37 (a) shows a top view
- FIG. 37 (b) shows an elevation view.
- the magnetic core 51 is different from the magnetic core 50 of FIG. 36 in the following points. That is, as shown in FIG. 37B, the magnetic core 51 is formed by laminating a magnetic core 51a, a magnetic core 51b, a magnetic core 51c, and a magnetic core 15d in that order in parallel with the wire to be measured. .
- the magnetic core 51 can be realized not only by a single layer integrated type but also by a laminated type.
- the magnetic core 51 has a four-layer structure of the magnetic core 51a to the magnetic core 51d, but may have a structure of two layers, three layers, or five layers or more.
- FIG. 38 shows one shape of the magnetic core
- FIG. 38 (a) is a perspective view of the magnetic core 50 of FIG. 36
- FIG. 38 (b) is a perspective view of the magnetic core 51 of FIG.
- the magnetic core 50 is integrally formed, whereas the magnetic core 51 has a laminated structure in which a plurality of magnetic cores are laminated in parallel to the wire to be measured.
- the shape of the magnetic core is not limited to a specific shape, and can be various shapes. Therefore, the shape of the magnetic core can be appropriately changed according to the design of the device, the layout inside the current sensor, and the like.
- FIG. 39 shows one shape of the magnetic core
- FIG. 39 (a) is a top view
- FIG. 39 (b) is a perspective view.
- the shape of the magnetic core 53 is substantially rectangular when viewed from above. More specifically, the magnetic core 53 is a single-layer type formed by docking a U-shaped first core portion 53a and a second core portion 53b. The first core portion 53a and the second core portion 53b are in close contact with each other on the surface (the upper surface in the drawing) constituting one surface of the quadrilateral shape. The first core portion 53a and the second core portion 53b form the magnetic flux leakage portion 3 and the element holding hole 5 on the surface (the lower surface in the drawing) facing the surface.
- the first open end surface of the first core portion 53a and the second open end surface of the second core portion 53b are separated from each other, whereby the magnetic flux leakage portion 3 is formed.
- the element holding hole 5 is formed by a first element holding hole provided in the first open end face and a second element holding hole provided in the second open end face.
- the element holding hole 5 is formed in a radial direction with respect to a current flowing through a measured electric wire (not shown), and penetrates the first core portion 53a and the second core portion 53b.
- FIG. 40 shows one shape of the magnetic core, FIG. 40 (a) is a top view, and FIG. 40 (b) is a perspective view.
- the magnetic core 54 is configured as a single-layer integrated type having a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in a radial direction with respect to a current flowing through a measured electric wire (not shown) and penetrates the magnetic core 54. Note that the first open end surface and the second open end surface are spaced apart and are not in contact with each other.
- the magnetic core can be realized by either a docking type or an integral type.
- FIG. 41 shows one shape of the magnetic core
- FIG. 41 (a) is a top view
- FIG. 41 (b) is a perspective view.
- the shape of the magnetic core 55 is substantially square when viewed from above. More specifically, the magnetic core 55 is a single-layer type formed by docking a U-shaped first core portion 55a and a second core portion 55b. The first core portion 55a and the second core portion 55b are in close contact with each other on a surface (surface on the upper side of the drawing) constituting one surface of the quadrilateral shape. The first core portion 55a and the second core portion 55b form the magnetic flux leakage portion 3 and the element holding hole 5 on the surface (the lower surface in the drawing) facing the surface.
- the first open end face of the first core portion 55a and the second open end face of the second core portion 55b are separated from each other, thereby forming the magnetic flux leakage portion 3.
- the element holding hole 5 is formed by a first element holding hole provided in the first open end face and a second element holding hole provided in the second open end face.
- the element holding hole 5 is formed in parallel to the current flowing through the wire to be measured (not shown), and penetrates the first core portion 55a and the second core portion 55b.
- FIG. 42 shows one shape of the magnetic core
- FIG. 42 (a) is a top view
- FIG. 42 (b) is a perspective view.
- the magnetic core 56 is formed of a single-layer integrated type having a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in parallel to the current flowing through the wire to be measured (not shown) and penetrates the magnetic core 56. Note that the first open end face and the second open end face are spaced apart and are not in contact with each other.
- the magnetic core according to the present embodiment can be realized as either a docking type or an integral type.
- FIG. 43 shows one shape of the magnetic core, FIG. 43 (a) is a top view, and FIG. 43 (b) is a perspective view.
- the magnetic core 57 is formed of a single-layer integrated type having a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in a radial direction with respect to a current flowing through the measurement target electric wire (not shown) and penetrates the magnetic core 57. Note that the first open end face and the second open end face are spaced apart and are not in contact with each other.
- FIG. 44 shows one shape of the magnetic core, FIG. 44 (a) is a top view, and FIG. 44 (b) is a perspective view.
- the magnetic core 58 is configured as a single-layer integrated type that has an annular shape when viewed from above.
- the element holding hole 5 is formed in a radial direction with respect to a current flowing through the measurement target electric wire (not shown) and penetrates the magnetic core 58. Note that the first open end face and the second open end face are spaced apart and are not in contact with each other.
- the magnetic core according to the present embodiment can be realized in a rectangular shape, a ring shape, or other shapes which are not described here.
- FIG. 45 shows one shape of the magnetic core
- FIG. 45 (a) is a top view
- FIG. 45 (b) is a perspective view.
- the magnetic core 59 is configured as a single layer integrated type having a quadrangular shape when viewed from above.
- the element holding hole 5 is formed in parallel to the current flowing through the wire to be measured (not shown) and penetrates the magnetic core 59. Note that the first open end face and the second open end face are spaced apart and are not in contact with each other.
- FIG. 46 shows one shape of the magnetic core, FIG. 46 (a) is a top view, and FIG. 46 (b) is a perspective view.
- the magnetic core 60 is configured as a single-layer integrated type that has an annular shape when viewed from above.
- the element holding hole 5 is formed in parallel to the current flowing through the wire to be measured (not shown) and penetrates the magnetic core 60. Note that the first open end face and the second open end face are spaced apart and are not in contact with each other.
- the magnetic core according to the present embodiment can be realized in a rectangular shape, a ring shape, or other shapes which are not described here.
- FIG. 47 shows one shape of the magnetic core
- FIG. 47 (a) is a perspective view
- FIG. 47 (b) is an enlarged view of the magnetic flux leakage portion 3 and the element holding hole 5.
- the shape of the magnetic core 61 is rectangular when viewed from above. More specifically, the magnetic core 61 is a single-layer type formed by docking a U-shaped first core portion 61a and a second core portion 61b. The first core portion 61a and the second core portion 61b are in close contact with each other on a surface (a surface on the upper side of the drawing) constituting one surface of the quadrilateral shape. The first core portion 61a and the second core portion 61b form the magnetic flux leakage portion 3 and the element holding hole 5 on the surface (the lower surface in the drawing) facing the surface.
- the element holding hole 5 is formed by a first element holding hole provided in the first open end face and a second element holding hole provided in the second open end face.
- the element holding hole 5 is formed in a radial direction with respect to a current flowing through a measured electric wire (not shown), and penetrates through the first core portion 61a and the second core portion 61b.
- FIG. 48 shows one shape of the magnetic core
- FIG. 48 (a) is a perspective view
- FIG. 48 (b) is an enlarged view of the magnetic flux leakage portion 3 and the element holding hole 5.
- the magnetic core 62 is the same as the magnetic core 61 of FIG. 47 in that it is a single layer type in which both the U-shaped first core portion 61a and the second core portion 61b are docked. However, in the magnetic core 62, the first open end surface related to the first core portion 62a and the second open end surface related to the second core portion 62b are not separated from each other and are in contact with each other. That is, the magnetic core 62 is formed with an abutting structure. And as demonstrated with reference to FIG. 10, even if it is a butting structure, the magnetic core 62 can acquire the effect similar to the magnetic core of a gap structure.
- the thickness of the magnetic core in the radial direction with respect to the current flowing through the wire to be measured does not affect the sensitivity of the entire current sensor including the magnetic core.
- the thickness of the magnetic core as viewed from above is compared.
- the thickness of the magnetic core 53 of FIG. 39A is smaller than that of the magnetic core 1 of FIG.
- this does not indicate that the magnetic core 53 is less sensitive than the magnetic core 1.
- FIG. 49 is a diagram for explaining that the sensitivity of the current sensor including the magnetic core does not decrease even when the thickness of the magnetic core is small, with reference to the magnetic core 53 of FIG. ) Is a perspective view, and FIG. 49B is a cross-sectional view.
- the radial direction is the x direction with respect to the current flowing through the measured wire (not shown), and the thickness of the magnetic core in the x direction is t.
- the thickness t of the magnetic core 53 is formed larger than the width of the magnetically sensitive portion of the magnetoelectric transducer 20.
- the magnitude of the magnetic flux in the element holding hole 5 is substantially constant in the x direction. Therefore, the sensitivity of the entire current sensor including the magnetic core 53 does not decrease even if t is small.
- the thickness t of the magnetic core 53 is smaller than that of the magnetic core 1, this does not mean that the sensitivity of the entire current sensor including the magnetic core 53 is affected. .
- a magnetic core according to the present invention is a magnetic core used for a current sensor, and is for holding a first open end surface in which a first element holding hole for holding a magnetoelectric conversion element is formed, and the magnetoelectric conversion element. And a second open end face facing the first open end face, in which the second element holding hole is formed.
- the magnetic core according to the present invention has a first open end face and a second open end face facing each other.
- a first element holding hole is formed in the first open end face
- a second element holding hole is formed in the second open end face
- the magnetoelectric conversion element is held by the first element holding hole and the second element holding hole.
- the presence of the first open end surface and the second open end surface that is, the presence of a gap (hereinafter referred to as “magnetic flux leakage portion”) between the first open end surface and the second open end surface.
- magnetic flux leakage portion a gap between the first open end surface and the second open end surface.
- the sensitivity of the magnetic core is better when the magnetic resistance of the magnetic flux leaking portion is lower, and when the width of the magnetic flux leaking portion (distance between the first open end surface and the second open end surface) is narrower, the magnetic flux leak The magnetoresistance at the entrance is reduced.
- the magnetoelectric conversion element is held by the first element holding hole and the second element holding hole formed in the first open end face and the second open end face. Therefore, the distance between the first open end face and the second open end face is not so wide that the magnetoelectric conversion element is placed therebetween. In other words, the distance between the first open end face and the second open end face becomes narrower. Therefore, in the magnetic core according to the present invention, the width of the magnetic flux leakage portion is narrow, and hence the magnetic resistance of the magnetic flux leakage portion is also reduced, so that the sensitivity of the current sensor using the magnetic core can be improved.
- the magnetic core according to the present invention has the conventional problem described with reference to FIG. 17A (the magnetoelectric conversion element is provided in the cut portion, and therefore the width of the cut portion must be widened). Therefore, it is possible to solve the problem that the sensitivity of the magnetic core decreases accordingly.
- the first element holding hole and the second element holding hole are not positioned along the outer edge of the magnetic core where magnetic flux is difficult to leak from the magnetic core, but the first open end face and the second open end face. Is formed.
- the magnetoelectric conversion element is held in the first element holding hole and the second element holding hole where magnetic flux easily leaks from the magnetic core, and is generated by a minute current. Sensitivity can be improved by collecting more magnetic flux in the magnetoelectric transducer.
- the magnetic core according to the present invention has the conventional problem described with reference to FIG. 17B (the magnetic core is placed on the notch formed along the outer edge of the magnetic core. Therefore, it is possible to solve the problem that the magnetic flux is difficult to leak from and the magnetic flux detected by the magnetoelectric conversion element becomes minute, thereby reducing the sensitivity of the magnetic core.
- the magnetic core according to the present invention can realize a magnetic core capable of increasing the detection sensitivity of the current sensor with the above-described configuration.
- the first element holding hole and the second element holding hole are configured so that the magnetoelectric conversion element is arranged so that a magnetosensitive direction of the magnetoelectric conversion element is a circumferential direction of the magnetic core.
- the structure may be held.
- the first element holding hole and the second element holding hole for holding the magnetoelectric conversion element in the thickness direction of the magnetoelectric conversion element are provided. Can be small. And since the magnetic flux which leaks from a magnetic core is amplified, so that the width
- the distance between the first open end face and the second open end face is preferably smaller than 2 mm.
- the first element holding hole and the second element holding hole have a magnetoelectric conversion element. Can no longer hold.
- the magnetoelectric conversion element can be held in the first element holding hole and the second element holding hole, and the magnetoelectric conversion element includes the first element holding hole and the second element holding hole. There is an effect that the magnetic flux leaking from the magnetic core can be surely sensed with respect to the hole.
- the first The element holding hole 5a and the second element holding hole 5b have a hole width (L2) in the thickness direction of the magnetoelectric conversion element 20 to be held, which is a distance between the first bottom face 16 and the second bottom face 17 (L1). It may be 75 times or less.
- hole is described using the expression “hole”.
- the expression “hole” may be used synonymously with a so-called “groove”, but “hole” is used as a unified expression in this specification.
- holding hole is used to mean a space necessary for arranging and storing the magnetoelectric transducer.
- the present invention can be applied to a magnetic core capable of increasing the detection sensitivity of a current sensor, a current sensor including the magnetic core, and a current measurement method using the current sensor including the magnetic core.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
- Transformers For Measuring Instruments (AREA)
Abstract
Description
上記磁気コアを備える電流センサによって、被測定電線に流れる電流の電流値を測定することが好ましい。
〔1.磁気コア1について〕
〔1-1.磁気コア1の概略構造〕
以下、本実施形態に係る磁気コア1の概略構造を説明する。なお、理解の容易のため、最初に磁気コア1を備えた電流センサについて説明し、次に磁気コア1の概略構造を説明する。
次に、磁気コア1の他の実施例を図2、図3により説明する。なお、図1を参照して説明した内容については、その説明を省略する。
次に、磁気コア1の形成方法を図4、及び図5により説明する。図4は、磁気コア1の形成方法を説明するための図であり、図4の(a)は、磁気コア1の上面図を、図4の(b)及び図4の(c)は、図4の(a)におけるA-A’断面図を示す。図4の(b)及び図4の(c)に示すように、磁気コア1は、単層で形成されても、あるいは、複数の層が積層されてなるものであってもよい。
〔2.磁気コア1に関する種々の測定結果〕
次に、磁気コア1に関する種々の測定結果を説明する。
まず、磁気コア1により磁束密度の測定感度が向上することを図7により説明する。図7は、公知の磁気コアおよび磁気コア1を用いた磁束密度の測定結果を示す図であり、同図の(a)は、図17の(a)の公知の磁気コアを用いた測定結果を、同図の(b)は、図17の(b)の公知の磁気コアを用いた測定結果を、同図の(c)は、同図の(b)の磁気コアに、さらに空隙部(本実施形態の磁束漏入部3に相当)が設けられた磁気コアによる測定結果を、それぞれ示す。また、同図の(d)は、素子保持孔5が被測定電線と平行に形成されている場合の磁気コア1による測定結果を、同図(e)は、素子保持孔5が被測定電線に対して垂直な方向に形成されている場合の磁気コア1による測定結果を、それぞれ示す図である。
上記のとおり、磁気コア1は、公知の磁気コアに比べて、磁束密度の測定感度が著しく向上する。そこで、その理由を図8により説明する。図8は、磁気コア1によって磁束密度の測定感度が向上することを説明するための図であって、磁束漏入部3に対する磁電変換素子20の位置関係を示す図である。
さらに、磁束漏入部3の幅(第1開放端面3aと第2開放端面3bとの距離)、素子保持孔5のサイズ等によって、磁気コア1による磁束密度の測定感度が影響を受けることを図9を用いて説明する。図9は、磁気コア1を用いた磁束密度の測定結果を示す図であり、同図の(a)は、各記号の定義を示すための図であり、同図の(b)は、L2を変化させたときの磁束密度を、同図の(c)は、L1を変化させたときの磁束密度を示すグラフである。
上述したように、製造上・加工上の理由により、磁気コア1が突き当て構造となる場合がある。そのような場合にも、磁気コア1は、ギャップ構造の場合と同様の効果を有する。このことを図10を用いて説明する。
さらに、素子保持孔5のサイズ(L1、L2)、及び磁束漏入部3の幅(W)が測定結果に与える影響について図11を参照して説明する。図11は、磁気コア1を用いた磁束密度の測定結果を示す図であり、同図の(a)は、各記号の定義を示すための図であり、同図の(b)は、L1を1mmとしたときの磁束密度を、同図の(c)は、L1を1.5mmとしたときの磁束密度を、同図の(d)は、L1を2mmとしたときの磁束密度を示すグラフである。なお、図11は、下記の表1をグラフ化したものである。
上記〔2-2.感度向上の仕組み〕において、磁気コアの感度は、磁束漏入部3の磁気抵抗がある程度低い方が良好となること、そのためには、磁束漏入部3の幅(W)が狭い方が、磁束漏入部3の磁気抵抗が低下することを述べた。ここでは、磁束漏入部3の磁気抵抗を下げる他の方法を図12により説明する。
次に、磁気コア1によってノイズ耐性が向上することを図13を用いて説明する。図13は、公知の磁気コアおよび磁気コア1を用いたノイズ耐性の測定結果を示す図であり、同図の(a)は、図17の(a)の公知の磁気コアを用いた測定結果を、同図の(b)は、図17の(b)の公知の磁気コアを用いた測定結果を、同図の(c)は、同図の(b)の磁気コアに、さらに空隙部(本実施形態の磁束漏入部3に相当)が設けられた磁気コアによる測定結果を、同図の(d)は、磁気コア1を用いた測定結果をそれぞれ示す。
〔3.磁気コア1によって得られる効果〕
以下、磁気コア1によって得られる効果を説明する。
〔4.磁気コア1の一適用事例〕
磁気コア1を備えた電流センサは、種々の用途に適用することができ、例えば、太陽電池・燃料電池などのパワーコンディショナーの漏電検知、ハイブリッドカーやプラグインハイブリッドカー等に車載されるバッテリー監視、あるいは、データセンタUPSのバッテリー監視など、幅広い分野において利用可能である。
〔5. 磁気コアを備えた電流センサ〕
次に、磁気コア1を備えた電流センサ30を図18から図24により説明する。なお、図1等を参照して説明した内容については、その説明を省略する。
〔6. 磁気コアのバリエーション〕
次に、磁気コアの種々の形状を図25から図48により説明する。ただし、ここで説明する磁気コアの形状はあくまで一例であって、これらに限られるものではない。
〔補足〕
なお、本願発明は、以下の構成によって実現されてもよい。
3 磁束漏入部
3a 第1開放端面
3b 第2開放端面
5 素子保持孔
5a 第1素子保持孔
5b 第2素子保持孔
7 接触点
16 側面(第1側面)
17 側面(第2側面)
20 磁電変換素子
Claims (13)
- 電流センサに用いられる磁気コアであって、
磁電変換素子が保持されるための第1素子保持孔が形成された第1開放端面と、
上記磁電変換素子が保持されるための第2素子保持孔が形成された、上記第1開放端面に対向する第2開放端面と、を有することを特徴とする磁気コア。 - 上記第1素子保持孔および上記第2素子保持孔では、上記磁電変換素子は、当該磁電変換素子の感磁方向が上記磁気コアの周方向となるように保持されることを特徴とする請求項1に記載の磁気コア。
- 上記第1素子保持孔および上記第2素子保持孔には、上記磁気コアよりも透磁率の低い低透磁率材料が充填されていることを特徴とする請求項1に記載の磁気コア。
- 上記第1開放端面と上記第2開放端面との間には、上記磁気コアよりも透磁率の低い低透磁率材料が充填されていることを特徴とする請求項3に記載の磁気コア。
- 上記低透磁率材料は、フェライト含有エポキシ樹脂、磁性流体、あるいは空気であることを特徴とする請求項3に記載の磁気コア。
- 上記低透磁率材料は、フェライト含有エポキシ樹脂、磁性流体、あるいは空気であることを特徴とする請求項4に記載の磁気コア。
- 上記第1素子保持孔を形成する側面のうち、上記第2素子保持孔を形成する側面と対向する側面を第1側面、上記第2素子保持孔を形成する側面のうち、上記第1側面と対向する側面を第2側面としたときに、
上記第1素子保持孔および上記第2素子保持孔は、保持する上記磁電変換素子の厚み方向における孔幅が、上記第1側面と上記第2側面との側面間距離の1.75倍以下であることを特徴とする請求項1に記載の磁気コア。 - 上記第1開放端面と上記第2開放端面との距離は、2mmよりも小さいことを特徴とする請求項1に記載の磁気コア。
- 上記第1開放端面および上記第2開放端面は、一部が互いに当接していることを特徴とする請求項1に記載の磁気コア。
- 上記第1素子保持孔および上記第2素子保持孔はそれぞれ、上記第1開放端面および上記第2開放端面において、上記磁気コアの厚み方向と平行な方向に沿って延設されていることを特徴とする請求項1に記載の磁気コア。
- 上記第1素子保持孔および上記第2素子保持孔はそれぞれ、上記第1開放端面および上記第2開放端面において、上記磁気コアの厚み方向と垂直な方向に沿って延設されていることを特徴とする請求項1に記載の磁気コア。
- 請求項1から11の何れか1項に記載の磁気コアを備えることを特徴とする電流センサ。
- 請求項1に記載の磁気コアを備える電流センサによって、被測定電線に流れる電流の電流値を測定することを特徴とする電流測定方法。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP11765333A EP2562551A1 (en) | 2010-03-31 | 2011-03-15 | Magnetic core, current sensor provided with the magnetic core, and current measuring method |
KR1020127003044A KR101259326B1 (ko) | 2010-03-31 | 2011-03-15 | 자기 코어, 당해 자기 코어를 구비한 전류 센서, 및 전류 측정 방법 |
CN2011800033175A CN102483431A (zh) | 2010-03-31 | 2011-03-15 | 磁芯、具备该磁芯的电流传感器及电流测定方法 |
US13/391,943 US20120217963A1 (en) | 2010-03-31 | 2011-03-15 | Magnetic core, current sensor provided with the magnetic core, and current measuring method |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2010-081555 | 2010-03-31 | ||
JP2010081555 | 2010-03-31 | ||
JP2011057281A JP4998631B2 (ja) | 2010-03-31 | 2011-03-15 | 磁気コア、当該磁気コアを備えた電流センサ、及び電流測定方法 |
JP2011-057281 | 2011-03-15 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011125431A1 true WO2011125431A1 (ja) | 2011-10-13 |
Family
ID=44762392
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2011/056119 WO2011125431A1 (ja) | 2010-03-31 | 2011-03-15 | 磁気コア、当該磁気コアを備えた電流センサ、及び電流測定方法 |
Country Status (6)
Country | Link |
---|---|
US (1) | US20120217963A1 (ja) |
EP (1) | EP2562551A1 (ja) |
JP (1) | JP4998631B2 (ja) |
KR (1) | KR101259326B1 (ja) |
CN (1) | CN102483431A (ja) |
WO (1) | WO2011125431A1 (ja) |
Families Citing this family (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102011102978B4 (de) * | 2011-05-23 | 2018-05-17 | Phoenix Contact Gmbh & Co. Kg | Strommessumformer |
CH705027A1 (de) * | 2011-05-30 | 2012-11-30 | Melexis Technologies Nv | Vorrichtung zur Messung eines durch ein elektrisches Kabel fliessenden Stroms. |
WO2014010013A1 (ja) * | 2012-07-09 | 2014-01-16 | 富士通株式会社 | 電流センサ用コア及び電流センサ |
US10345344B2 (en) * | 2014-04-04 | 2019-07-09 | Eaton Intelligent Power Limited | Magnetic sensor with thin-walled magnetic core and methods of manufacture |
JP2015210246A (ja) * | 2014-04-30 | 2015-11-24 | 日本電産サンキョー株式会社 | 電流センサ |
JP2015210247A (ja) * | 2014-04-30 | 2015-11-24 | 日本電産サンキョー株式会社 | 電流センサ |
WO2016125367A1 (ja) | 2015-02-02 | 2016-08-11 | 株式会社村田製作所 | 電流センサ |
JP6597076B2 (ja) * | 2015-09-03 | 2019-10-30 | 日立金属株式会社 | 漏電検出器 |
GB2546532B (en) * | 2016-01-22 | 2018-03-21 | Gmc I Prosys Ltd | Measurement device |
JP6719771B2 (ja) * | 2016-09-29 | 2020-07-08 | 株式会社エス・エッチ・ティ | コア部材、ギャップ付コア、電流センサー及びギャップ付コアの製造方法 |
JP6790774B2 (ja) * | 2016-12-06 | 2020-11-25 | アイシン精機株式会社 | 電流センサ |
US10718825B2 (en) * | 2017-09-13 | 2020-07-21 | Nxp B.V. | Stray magnetic field robust magnetic field sensor and system |
JP6605007B2 (ja) * | 2017-10-12 | 2019-11-13 | 株式会社タムラ製作所 | 電流検出器 |
JP7281442B2 (ja) * | 2020-12-14 | 2023-05-25 | 横河電機株式会社 | 分割型センサヘッド及び分割型電流センサ |
CN112881778B (zh) * | 2021-01-19 | 2022-07-29 | 西南交通大学 | 一种全包围开合式小电流传感器 |
US20240248154A1 (en) * | 2021-07-05 | 2024-07-25 | Citizen Finedevice Co., Ltd. | Magnetic field sensor head and magnetic field sensor device |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1992012432A1 (en) * | 1990-12-28 | 1992-07-23 | Liaisons Electroniques-Mecaniques Lem S.A. | A current sensor device |
JPH07209337A (ja) * | 1993-12-30 | 1995-08-11 | At & T Corp | 高感度を有する磁気抵抗電流センサ |
JPH0815321A (ja) * | 1994-06-30 | 1996-01-19 | Hioki Ee Corp | 電流センサ |
JPH09508204A (ja) * | 1994-01-19 | 1997-08-19 | レム ヘーム リミテド | 磁気センサー |
JPH10232259A (ja) | 1997-02-21 | 1998-09-02 | Matsushita Electric Works Ltd | 漏電センサー |
JP2005049311A (ja) | 2003-07-31 | 2005-02-24 | Nec Tokin Corp | 電流センサ |
JP2006071457A (ja) * | 2004-09-02 | 2006-03-16 | Denso Corp | 電流計測装置 |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4113496A1 (de) * | 1991-04-25 | 1992-10-29 | Vacuumschmelze Gmbh | Magnetkern fuer einen stromsensor nach dem kompensationsprinzip |
US6759840B2 (en) * | 2002-06-11 | 2004-07-06 | Rockwell Automation Technologies, Inc. | Hall effect conductor/core method and apparatus |
EP1450176A1 (en) * | 2003-02-21 | 2004-08-25 | Liaisons Electroniques-Mecaniques Lem S.A. | Magnetic field sensor and electrical current sensor therewith |
US7205757B2 (en) * | 2004-09-02 | 2007-04-17 | Denso Corporation | High precision current sensor |
FR2911690B1 (fr) * | 2007-01-19 | 2009-03-06 | Thales Sa | Dispositif d'amplification magnetique comportant un capteur magnetique a sensibilite longitudinale |
US7936164B2 (en) * | 2008-07-03 | 2011-05-03 | Allegro Microsystems, Inc. | Folding current sensor |
US8638092B2 (en) * | 2010-08-06 | 2014-01-28 | Honeywell International, Inc. | Current sensor |
-
2011
- 2011-03-15 US US13/391,943 patent/US20120217963A1/en not_active Abandoned
- 2011-03-15 EP EP11765333A patent/EP2562551A1/en not_active Withdrawn
- 2011-03-15 JP JP2011057281A patent/JP4998631B2/ja not_active Expired - Fee Related
- 2011-03-15 WO PCT/JP2011/056119 patent/WO2011125431A1/ja active Application Filing
- 2011-03-15 KR KR1020127003044A patent/KR101259326B1/ko not_active IP Right Cessation
- 2011-03-15 CN CN2011800033175A patent/CN102483431A/zh active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1992012432A1 (en) * | 1990-12-28 | 1992-07-23 | Liaisons Electroniques-Mecaniques Lem S.A. | A current sensor device |
JPH07209337A (ja) * | 1993-12-30 | 1995-08-11 | At & T Corp | 高感度を有する磁気抵抗電流センサ |
JPH09508204A (ja) * | 1994-01-19 | 1997-08-19 | レム ヘーム リミテド | 磁気センサー |
JPH0815321A (ja) * | 1994-06-30 | 1996-01-19 | Hioki Ee Corp | 電流センサ |
JPH10232259A (ja) | 1997-02-21 | 1998-09-02 | Matsushita Electric Works Ltd | 漏電センサー |
JP2005049311A (ja) | 2003-07-31 | 2005-02-24 | Nec Tokin Corp | 電流センサ |
JP2006071457A (ja) * | 2004-09-02 | 2006-03-16 | Denso Corp | 電流計測装置 |
Also Published As
Publication number | Publication date |
---|---|
JP4998631B2 (ja) | 2012-08-15 |
KR20120031306A (ko) | 2012-04-02 |
JP2011227062A (ja) | 2011-11-10 |
CN102483431A (zh) | 2012-05-30 |
EP2562551A1 (en) | 2013-02-27 |
KR101259326B1 (ko) | 2013-05-06 |
US20120217963A1 (en) | 2012-08-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4998631B2 (ja) | 磁気コア、当該磁気コアを備えた電流センサ、及び電流測定方法 | |
US10353020B2 (en) | Manufacturing method for integrated multilayer magnetoresistive sensor | |
EP3045926B1 (en) | Single-chip z-axis linear magnetoresistive sensor | |
US9274180B2 (en) | Microfabricated magnetic field transducer with flux guide | |
US9116198B2 (en) | Planar three-axis magnetometer | |
US9417269B2 (en) | Current sensor | |
WO2015133621A1 (ja) | 電流量検出器 | |
JP2016502098A (ja) | 磁気センシング装置及びその磁気誘導方法 | |
JP2016517952A (ja) | 磁気センシング装置及びその磁気誘導方法、製造プロセス | |
CN104218147B (zh) | 磁传感器的制备方法以及磁传感器 | |
CN109655767A (zh) | 一种集成磁结构 | |
CN117075007A (zh) | Z轴磁场传感器及其加工制备方法 | |
WO2022067599A1 (zh) | 三轴向霍尔磁力计 | |
JP2011174775A (ja) | 電流センサ | |
CN203337153U (zh) | 一种三轴数字指南针 | |
JP2013047610A (ja) | 磁気平衡式電流センサ | |
CN113945872A (zh) | 一种z轴梯度磁场传感器芯片 | |
JP6597076B2 (ja) | 漏電検出器 | |
CN104347798A (zh) | 一种磁传感器及其制备方法 | |
US20240219487A1 (en) | Sensor device with circuit and integrated component for magneto-impedance measurement, and method of producing same | |
CN104218149B (zh) | 磁传感器的制备方法以及磁传感器 | |
JP6285641B2 (ja) | 磁気センサ及び磁場成分演算方法 | |
TW202246781A (zh) | 電流感測器與裝置 | |
CN104375098A (zh) | 磁传感装置及该装置的制备工艺 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201180003317.5 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11765333 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20127003044 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2011765333 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13391943 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |