WO1992012432A1 - Dispositif detecteur de courant - Google Patents

Dispositif detecteur de courant Download PDF

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Publication number
WO1992012432A1
WO1992012432A1 PCT/EP1991/002498 EP9102498W WO9212432A1 WO 1992012432 A1 WO1992012432 A1 WO 1992012432A1 EP 9102498 W EP9102498 W EP 9102498W WO 9212432 A1 WO9212432 A1 WO 9212432A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic circuit
sensor device
branches
recess
circuit
Prior art date
Application number
PCT/EP1991/002498
Other languages
English (en)
Inventor
Marcel Etter
Original Assignee
Liaisons Electroniques-Mecaniques Lem S.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Liaisons Electroniques-Mecaniques Lem S.A. filed Critical Liaisons Electroniques-Mecaniques Lem S.A.
Publication of WO1992012432A1 publication Critical patent/WO1992012432A1/fr

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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
    • G01R15/207—Constructional details independent of the type of device used

Definitions

  • the present invention is concerned with a current sensor device for measuring the current flowing in a primary conductor and/or for producing an image of this current, comprising at least one magnetic circuit capable of being coupled with said primary conductor and being coupled with at least one measuring coil, the magnetic circuit having at least one discontinuity between two of its branches, a magnetic field detector being arranged at the location of said circuit discontinuity.
  • the invention is more particularly directed to current sensor devices operating according to the compensation principle, as it is described, for example, in U.S. patent No 4,939,449.
  • Those devices include an electric compensation circuit controlled by the magnetic field detector and arranged so as to supply to the measuring coil a current tending to create in the magnetic circuit a magnetic field which compensates the magnetic field corresponding to the ampere-turns of the primary current to be measured.
  • the magnetic circuit includes an air gap, the height of which is such as to allow the lodging therein of the magnetic field detector, for example a Hall-effect detector.
  • Such a relatively important air gap is a minor inconvenience as long as the voltage output from the compensation circuit is sufficient for supplying the necessary compensation current to the measuring coil.
  • the current to be measured is an alternating or a pulsed current of a relatively high amplitude
  • the voltage output from the compensation circuit can be found to be limited, due to the characteristics of the power amplifier used in this circuit, so that the compensation is no ionger assured. A measuring error then appears, which is all the greater, the larger the air gap.
  • an electric saturation of the compensation circuit concerns mainly high current sensors with several air gaps, in which the measuring coils have a high impedance and the coupling of these coils with the primary conductor is poor.
  • the electric saturation can then occur as from relatively low frequencies, since, for example already at 50 Hz, the voltage to be applied to the measuring coils for achieving compensation is more than twice the value calculated when taking into account the sole ohmic voltage drop.
  • the invention is aimed, in particular, at avoiding this inconvenience and at providing a current sensor device of a very high precision even for alternating currents or pulsed currents of high intensity, as they can occur, in particular, in the case of a short-circuit in the primary current circuit.
  • the end portion of at least a first of said branches of the magnetic circuit forming said discontinuity comprises on one part of its surface a recess in which said field detector is lodged, the remaining of said surface forming with the surface of the end portion of the other of said branches an air gap, the height of which is small as compared to the depth of said recess.
  • the recess is a notch in the end portion of said branch of the magnetic circuit.
  • each one of the respective end portions of said branches of the magnetic circuit comprises a recess, the total depth of the two recesses being chosen so as to allow the lodging of said field detector in the space formed by these recesses.
  • the recess can be formed in a central part of the surface of the end portion of said branch of the magnetic circuit, or in a peripheral part of this surface and is located preferably on the inside of the magnetic circuit.
  • the parts of the respective surfaces of the end portions of the branches forming said air gap in the vicinity of the recess can be separated by a sheet of a material of low magnetic permeability. In the case of a magnetic circuit formed of a stack of sheet metal, the portions of the surfaces forming said air gap can be practically in physical contact.
  • the discontinuities are formed at the angles of the circuit, the surfaces of the ends of the branches concerned being, for example, at an angle with respect to the general direction of these branches.
  • a rectangular magnetic circuit is formed of two L-shaped parts or L-shaped stacks of sheet metal.
  • Fig. 1 is a schematic side view of a sensor device according to the invention, having a magnetic circuit with two discontinuities;
  • Fig. 2 is an enlarged view of a discontinuity according to another embodiment of the invention.
  • Fig. 3 is an enlarged view of a discontinuity according to a further embodiment of the invention.
  • Fig. 4 is an enlarged view of a discontinuity provided in the regions of the angles of a rectangular magnetic circuit.
  • Fig. 5 is a schematic side view of a sensor device having magnetic field detectors located in the regions of the angles of a rectangular magnetic circuit according to still another embodiment of the invention, together with a schematic electric circuit diagram of the sensor device.
  • Fig. 1 shows a current sensor device comprising a magnetic circuit 1 surrounding a primary conductor 10, represented in cross section, in which flows the current to be measured.
  • Two pairs of measuring coils 13, 14 and 15, 16 are coupled with the magnetic circuit 1 formed, in this example, of two U-shaped parts 2, 3.
  • the ends of the branches of these two U-shaped parts are arranged facing each other, to form two discontinuities 4 and 5 in the magnetic circuit 1.
  • the discontinuities of the magnetic circuit comprise air gaps 6 and 7 of a very small height, in the vicinity of recesses 8 and 9 in the ends of two respective branches of the U-shaped parts.
  • these recesses are notches, the depth of which is chosen so as to allow lodging therein respective magnetic field detectors 11 and 12. According to the above-mentioned known measuring principle, these detectors control a compensation circuit (not shown in Fig. 1), in such a way that the latter supplies a compensation current to the coils 13 to 16 coupled with the magnetic circuit.
  • the magnetic flux detected by the detectors is substantially identical to the flux these detectors would detect if the discontinuities were uniform air gaps of the same height as the depth of the recesses, the difference in ampere-turns between the primary current and the compensation current being supposed to be the same in both cases, said difference constituting the measuring error of the device.
  • the very high magnetic permeability of the materials used for making the core of the circuit allows to consider the field necessary for the circulation of the flux inside this core, as being equal to zero, and to take into account only the field in the discontinuity.
  • the product H x L is constant, L being the length of the discontinuity in the direction of a line of the field H.
  • the field H will be very strong.
  • the field will be weak, but substantially the same as in the case of a uniform air gap of the same height as the depth of the notch.
  • Fig. 2 shows an arrangement of notches in a central part of the opposite ends of two branches 22, 23 of the magnetic circuit forming an air gap 24, according to which these ends each have a notch.
  • the overall depth of both notches 27 and 28 arranged facing each other is such that a magnetic field detector, for example a Hall-effect device 29, may be lodged therein.
  • Fig. 3 shows another version of the arrangement of recesses or notches, in the ends of two corresponding branches 32, 33 of a magnetic circuit similar to that of Fig. 1 .
  • notches such as 37 are formed in a peripheral portion of the discontinuity 34.
  • the notches are preferably located on the inside of the branch, when viewing the circuit as in Fig. 1 .
  • This kind of recess is also of particular interest from the standpoint of the making of the notch, when the magnetic circuit comprises a ring- shaped core with a single discontinuity.
  • Fig. 4 shows a configuration which can be used in particular for a magnetic circuit of generally rectangular shape, in which discontinuities are provided in the regions forming the angles of the circuit.
  • the branches 42, 43 of two circuit parts having each the general shape of a L form a discontinuity 44 in a plane at an angle with respect to the generai direction of these branches.
  • One or both of the opposite surfaces comprise a recess or a notch similar to that of the preceding embodiments.
  • One of the advantages of this configuration is that the surface of the discontinuity is greater than the transverse section of the branches of the circuit, which increases the section of the core outside the notch and extends the magnetic saturation limit of the circuit.
  • Fig. 5 shows still another arrangement in which a magnetic circuit, comprised of two L-shaped parts 52 and 53, also exhibits two discontinuities located at opposite angles, but in such a manner that of the two opposite surfaces of a discontinuity, one is parallel to the direction of one of the branches and the other perpendicular to the direction of the other branch. It can be noted that making lamellar magnetic circuits from sheet metal in which individual sheets are L-shaped, offers the possibility of cutting out such pieces from a metal band substantially without loss of material.
  • the magnetic circuit formed of parts 52 and 53 surrounds a primary conductor 50 in a similar manner as in Fig. 1 , and it is further coupled with two measuring coils 54, 55.
  • Hall-effect devices 56, 57 are lodged in recesses 58, 59 of the magnetic circuit and are each connected through resistors to the terminals +,- of a current source.
  • the output terminals of the devices 56, 57 are connected to the inputs of respective amplifiers 60, 61 and the outputs of these amplifiers are connected to a respective first terminal of the measuring coils 54, 55.
  • the second terminals of these coils are connected together and to a measuring resistor 62. Across this resistor 62 appears a voltage drop which is proportional to the compensating current supplied to the measuring coils to compensate the magnetic flux created by the primary current flowing in the conductor 50.
  • the air gap formed in the vicinity of the recess has a height substantially smaller than the depth of the recess.
  • This air gap is useful for avoiding a too high remanent flux density in the magnetic circuit.
  • the height of the air gap can be defined by a strip of a material of low magnetic permeability, placed between the end surfaces of corresponding branches of the circuit. In the case of a circuit with a laminar structure, the irregular nature of the surface resulting from the assembling of metal sheets piled one upon the other, may be sufficient for forming the air gap without additional means for defining the same.
  • the air gap has a height which is substantially smaller than the one necessary for lodging a magnetic field detector in such an air gap, improves significantly the coupling between the primary conductor and the measuring coils. This makes it possible to substantially reduce the measuring error of the current sensor. Furthermore, the recess used for lodging the magnetic field detector provides a physical protection for the same, thus preventing the risk of the detector being crushed which is an additional advantage of the present arrangement.

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

Abstract

Dispositif détecteur de courant permettant de mesurer le flux de courant circulant dans un conducteur primaire (50) et comprenant un circuit magnétique (52, 53) que l'on peut connecter audit conducteur primaire ainsi qu'à des bobines de mesure (54, 55). Ledit circuit magnétique présente des discontinuités et comprend des détecteurs de champ magnétique (56, 57) qui sont montés dans des évidements (58, 59) situés à l'endroit des discontinuités du circuit. La surface entourant chaque évidement forme, avec une surface opposée du circuit, un entrefer, dont la hauteur est inférieure à la profondeur de l'évidement.
PCT/EP1991/002498 1990-12-28 1991-12-23 Dispositif detecteur de courant WO1992012432A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH414290 1990-12-28
CH4142/90.3 1990-12-28

Publications (1)

Publication Number Publication Date
WO1992012432A1 true WO1992012432A1 (fr) 1992-07-23

Family

ID=4270607

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1991/002498 WO1992012432A1 (fr) 1990-12-28 1991-12-23 Dispositif detecteur de courant

Country Status (2)

Country Link
CN (1) CN1062792A (fr)
WO (1) WO1992012432A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995020167A1 (fr) * 1994-01-19 1995-07-27 Lem Heme Limited Detecteur de courant comprenant des capteurs magnetiques
WO2011125431A1 (fr) * 2010-03-31 2011-10-13 オムロン株式会社 Noyau magnétique, capteur de courant comprenant le noyau magnétique, et procédé de mesure de courant
DE102011080034A1 (de) * 2011-07-28 2013-01-31 Vacuumschmelze Gmbh & Co. Kg Stromsensoranordnung
US20130027033A1 (en) * 2011-07-28 2013-01-31 Vacuumschmelze Gmbh & Co. Kg Current sensor arrangement
DE102011080039A1 (de) * 2011-07-28 2013-04-18 Vacuumschmelze Gmbh & Co. Kg Stromsensoranordnung
JP2014215103A (ja) * 2013-04-24 2014-11-17 日置電機株式会社 電流センサ
EP2860535A1 (fr) * 2013-10-02 2015-04-15 Rockwell Automation Technologies, Inc. Noyau de capteur à effet hall avec plusieurs espaces d'air
JPWO2014010013A1 (ja) * 2012-07-09 2016-06-20 富士通株式会社 電流センサ用コア及び電流センサ

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE60304460T2 (de) * 2003-07-12 2006-10-12 Liaisons Electroniques-Mécaniques LEM S.A. Stromsensor mit einem einen Luftspalt aufweisenden Magnetkern und damit ausgerüstete Energieversorgungsschaltung
CN100365419C (zh) * 2006-01-17 2008-01-30 王清波 直流电流非接触测量方法
CN102969138B (zh) * 2012-12-11 2014-10-15 吉林省电力有限公司电力科学研究院 0.2Ss级特种高压计量电流互感器
CN109298356B (zh) * 2018-09-20 2024-05-14 中国原子能科学研究院 一种超导回旋加速器中高精度磁场测量感应线圈探头

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1905468A1 (de) * 1969-01-31 1970-09-10 Licentia Gmbh Strommesszange
JPS5748662A (en) * 1980-09-08 1982-03-20 Fujitsu Ltd Large current measuring device
EP0072422A1 (fr) * 1981-07-31 1983-02-23 Vacuumschmelze GmbH Noyau en matériau magnétique doux pour mesurer un courant continu ou alternatif à l'aide d'un élément semiconducteur sensible au champ magnétique
DE3705450A1 (de) * 1987-02-20 1988-09-01 Vacuumschmelze Gmbh Stromwandler zur messung von rechteckstroemen nach dem kompensationsprinzip
US4914383A (en) * 1985-10-10 1990-04-03 Wilkerson A W Non-contact ammeter

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1905468A1 (de) * 1969-01-31 1970-09-10 Licentia Gmbh Strommesszange
JPS5748662A (en) * 1980-09-08 1982-03-20 Fujitsu Ltd Large current measuring device
EP0072422A1 (fr) * 1981-07-31 1983-02-23 Vacuumschmelze GmbH Noyau en matériau magnétique doux pour mesurer un courant continu ou alternatif à l'aide d'un élément semiconducteur sensible au champ magnétique
US4914383A (en) * 1985-10-10 1990-04-03 Wilkerson A W Non-contact ammeter
DE3705450A1 (de) * 1987-02-20 1988-09-01 Vacuumschmelze Gmbh Stromwandler zur messung von rechteckstroemen nach dem kompensationsprinzip

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 6, no. 121 (P-126)(999) 6 July 1982 & JP,A,57 048 662 ( FUJITSU ) 20 March 1982 & JP, *

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995020167A1 (fr) * 1994-01-19 1995-07-27 Lem Heme Limited Detecteur de courant comprenant des capteurs magnetiques
US5825175A (en) * 1994-01-19 1998-10-20 Lem Heme Limited Magnetic sensors
WO2011125431A1 (fr) * 2010-03-31 2011-10-13 オムロン株式会社 Noyau magnétique, capteur de courant comprenant le noyau magnétique, et procédé de mesure de courant
JP2011227062A (ja) * 2010-03-31 2011-11-10 Omron Corp 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
KR101259326B1 (ko) * 2010-03-31 2013-05-06 오므론 가부시키가이샤 자기 코어, 당해 자기 코어를 구비한 전류 센서, 및 전류 측정 방법
DE102011080039A1 (de) * 2011-07-28 2013-04-18 Vacuumschmelze Gmbh & Co. Kg Stromsensoranordnung
US20130057272A1 (en) * 2011-07-28 2013-03-07 Vacuumschmelze Gmbh & Co. Kg Current sensor arrangement
DE102011080041A1 (de) * 2011-07-28 2013-04-11 Vacuumschmelze Gmbh & Co. Kg Stromsensoranordnung
US20130027033A1 (en) * 2011-07-28 2013-01-31 Vacuumschmelze Gmbh & Co. Kg Current sensor arrangement
DE102011080034A1 (de) * 2011-07-28 2013-01-31 Vacuumschmelze Gmbh & Co. Kg Stromsensoranordnung
US8941373B2 (en) 2011-07-28 2015-01-27 Vacuumschmelze Gmbh & Co. Kg Current sensor arrangement
EP2551678A3 (fr) * 2011-07-28 2017-07-26 Vaccumschmelze Gmbh & Co. KG Agencement de capteur de courant
EP2551679A3 (fr) * 2011-07-28 2017-09-27 Vaccumschmelze Gmbh & Co. KG Agencement de capteur de courant
EP2551680A3 (fr) * 2011-07-28 2017-12-06 Vaccumschmelze Gmbh & Co. KG Agencement de capteur de courant
JPWO2014010013A1 (ja) * 2012-07-09 2016-06-20 富士通株式会社 電流センサ用コア及び電流センサ
JP2014215103A (ja) * 2013-04-24 2014-11-17 日置電機株式会社 電流センサ
EP2860535A1 (fr) * 2013-10-02 2015-04-15 Rockwell Automation Technologies, Inc. Noyau de capteur à effet hall avec plusieurs espaces d'air
US9285437B2 (en) 2013-10-02 2016-03-15 Rockwell Automation Technologies, Inc. Hall effect sensor core with multiple air gaps

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Publication number Publication date
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