WO2010041139A1 - Bobine de mesure de courant électrique - Google Patents

Bobine de mesure de courant électrique Download PDF

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Publication number
WO2010041139A1
WO2010041139A1 PCT/IB2009/007107 IB2009007107W WO2010041139A1 WO 2010041139 A1 WO2010041139 A1 WO 2010041139A1 IB 2009007107 W IB2009007107 W IB 2009007107W WO 2010041139 A1 WO2010041139 A1 WO 2010041139A1
Authority
WO
WIPO (PCT)
Prior art keywords
coil
loop
conductor
loops
electrical current
Prior art date
Application number
PCT/IB2009/007107
Other languages
English (en)
Inventor
Michael David Grant
Kenneth John Nixon
Original Assignee
University Of Witwatersrand, Johannesburg
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 University Of Witwatersrand, Johannesburg filed Critical University Of Witwatersrand, Johannesburg
Publication of WO2010041139A1 publication Critical patent/WO2010041139A1/fr
Priority to ZA2011/01839A priority Critical patent/ZA201101839B/en

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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
    • G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
    • G01R15/181—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using coils without a magnetic core, e.g. Rogowski coils

Definitions

  • This invention relates to an electrical current measuring coil, and in particular to an improvement to Rogowski coils, which are used for a wide range of electrical current measurements.
  • Another form of current measurement is direct coupling of a coil to the magnetic field of a current carrying conductor. This is achieved by wrapping a coil around a common magnetic core, around which the conductor is also wrapped. A current is then induced in the coil, which can be measured as above.
  • the disadvantage of this method is that this directly loads the circuit and has a similar effect of adding an impedance.
  • Rogowski coil is a helical coil comprising a plurality of turns, the coil enclosing the current carrying conductor.
  • the coil operates through the application of Faraday and Ampere's laws, which together describe the relationship between a coil and an enclosed current carrying conductor, and the output of the coil, respectively.
  • Rogowski coils are ideally suited for alternating or current transients and have been used in applications ranging from the measurement of power transients in motors to electron beam measurements. Since the helical coil has an air core it does not saturate at high current transients or exhibit hysteresis effects.
  • the total flux of the coil can thus be recovered as the path integral along the coil:
  • V ( t) ⁇ o nA- dt
  • the output from the Rogowski coil needs to be integrated in the time domain. This is very easily achieved through either an active integrator system (commonly used when measuring relatively low frequency signals) or a passive integrator when measuring high frequency (usually high energy) signals.
  • the primary disadvantage is the inter-turn capacitance between the turns of the helical coil which limits the highest frequency the coil will respond to. Additionally the coil has an inductive component when the signal is loaded or when fast transients are applied through the current carrying conductor.
  • a coil for measuring electrical current in a conductor surrounded by the coil comprising at least one geometrically closed loop.
  • each loop comprises an incoming conductor, an outgoing conductor and an intermediate loop-defining conductor that bends round and crosses over itself.
  • the coil comprises a plurality of geometrically closed loops that are electrically interconnected. -A-
  • the coil comprises a first loop, an end loop and at least one intermediate loop between the first and end loops, with adjacent loops being electrically interconnected.
  • the incoming conductor of the first loop defines a first terminal connector
  • the outgoing conductor of the end loop defines a second terminal connector, the first and second terminal connectors being connectable to an external measuring circuit.
  • the outgoing conductor of the end loop extends through the end loop, through the at least one intermediate loop and through the first loop, so as to be enclosed by the loops, and ultimately extending from the coil substantially together with the incoming conductor of the first loop.
  • each loop is substantially circular.
  • the loop may be triangular, rectangular or oval, or any other shape provided that it is substantially closed.
  • the loop defines a plane that is substantially perpendicular to a magnetic field, defined by magnetic field lines, resulting from the electrical current in the conductor.
  • the coil is substantially toroidal, with the plurality of geometrically closed loops being substantially evenly distributed around the coil.
  • additional turns of the coil surround a current carrying conductor to form an inter loop space substantially distributed around more than one coil.
  • a method of constructing an electrical current measuring coil for measuring electrical current in a conductor surrounded by the coil comprising providing a length of conductor and forming the conductor into at least one geometrically closed loop.
  • each loop comprises an incoming conductor, an outgoing conductor and an intermediate loop-defining conductor, the method comprising bending the intermediate loop-defining conductor so that it crosses over itself.
  • the method comprises forming a plurality of geometrically closed loops, with adjacent closed loops being interconnected.
  • the method comprises extending an outgoing conductor of an end loop through the end loop, through an at least one intermediate loop and through a first loop, so as to be enclosed by the loops.
  • each loop is formed substantially circular, triangular, rectangular or oval.
  • the method comprises forming the coil into a torus, with the plurality of geometrically closed loops being substantially evenly distributed around the coil.
  • the method comprises additional turns of the coil being added around the current carrying conductor leaving the inter loop space substantially distributed around more than one coil.
  • Figure 1 shows a typical Rogowski coil
  • Figure 2 shows one geometrically closed loop of an electrical current measuring coil according to the present invention
  • Figure 3 shows the connection between two adjacent loops of an electrical current measuring coil according to the present invention, with a first loop comprising an incoming conductor that defines a first terminal connector;
  • Figure 4 shows an end loop of the electrical current measuring coil according to the present invention, with an outgoing conductor of the end loop returning through the loops so as to define a second terminal connector, as shown in Figure 3;
  • Figure 5 shows an electrical current measuring coil of a preferred embodiment of the present invention, the coil being substantially toroidal and comprising eight geometrically closed loops that are substantially evenly distributed around the coil.
  • the helical coil has been revised as shown in Figures 2 to 5.
  • a coil 10 for measuring electrical current in a conductor 12 surrounded by the coil 10 is provided.
  • the coil 10 comprises at least one geometrically closed, substantially circular, loop 14.
  • the loop 14 may, however, take on any other regular shape, such as triangular, rectangular or oval.
  • each loop 14 comprises an incoming conductor 16, an outgoing conductor 18 and an intermediate loop-defining conductor 20.
  • the intermediate loop-defining conductor 20 bends round and crosses over itself at point 22 so that the incoming conductor 16 is enclosed within the loop 14.
  • the coil 10 comprises a plurality of geometrically closed loops 14 that are electrically interconnected.
  • the coil 10 comprises a first loop 14.1 , an end loop 14.n and at least one intermediate loop (14.2 in Figure 3, 14.n-1 in Figure 4 and 14.2 to 14.7 in Figure 5) between the first and end loops, with adjacent loops being electrically interconnected.
  • the incoming conductor 16 of the first loop 14.1 defines a first terminal connector 24, and the outgoing conductor 18 of the end loop 14.
  • n defines a second terminal connector 26.
  • the first and second terminal connectors 24, 26 are connectable to an external measuring circuit, such as the active or passive integrator systems described above.
  • the outgoing conductor 18 of the end loop 14. n extends through the end loop 14.n, through the at least one intermediate loop and through the first loop 14.1 , so as to be enclosed by the loops 14.
  • the outgoing conductor 18 of the end loop 14.n ultimately extends from the coil 10 substantially together with the incoming conductor 16 of the first loop 14.1 , as also shown in Figure 5.
  • the inductance of the coil 10 that is the collection of loops formed in a roughly circular fashion, is reduced. Additionally, if there are any currents induced in the conductors connecting the loops 14 together, they are cancelled by the fact that the same currents would be induced in the returning outgoing conductor 18 of the end loop 14.n. Since the direction of the induced currents is the same, and the conductor is continuous throughout the coil 10, the direction of one of the induced currents is inverted, and hence in their combination their contribution to the signal at the terminal connectors 24, 26 of the coil 10 is zero.
  • the loops 14 define planes 28 that are substantially perpendicular to a magnetic field, defined by magnetic field lines 30, resulting from the electrical current in the conductor 12.
  • Figure 5 also shows a preferred embodiment of the invention, in which the coil 10 is open-ended and substantially toroidal, with eight geometrically closed, interconnected, discrete loops 14.1 to 14.8 being substantially evenly distributed around the coil 10.
  • the coil 10 comprises three approximately equi-spaced discrete loops 14.
  • a conventional Rogowski coil may be modified so as to include at least one additional geometrically closed loop, of the type described above, so as to have one coil comprising a plurality of conventional helical coil turns and at least one geometrically closed loop of the present invention.
  • the coil 10 may be added to a conventional Rogowski coil, so that there are two coils around the conductor 12.
  • two coils 10 of the present invention may be wrapped around the conductor 12. The effect of these further versions is to increase the signal strength at the terminal connectors, without compromising the bandwidth performance that the discrete loops provide.
  • the number of turns around the current carrying conductor 12 is not limited.
  • the coil 10 may be made in any one of the following ways:
  • Coil winding a mechanical process is used to wrap a turn of conductive material around a component in the shape required and, if necessary, bond the material to the component.
  • Electrolysis deposit a suitable electrolysis method is used to deposit conductive material onto a suitable formed component, thereby forming the complete discrete turn.
  • PCB screening a suitably designed complete turn is screen printed onto a circuit board which is then connected to other circuit boards to form the discrete closed turns.
  • Laser etched a laser is used to remove material from a block of conductive material, leaving the complete discrete turn behind.
  • Casting a mold is made of the discrete turn and each turn is formed by casting conductive material into the mold.
  • the present invention thus provides an electrical current measuring coil that addresses the disadvantages of a Rogowski coil in a simple, yet effective manner.

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

Selon un premier aspect de l'invention, il est proposé une bobine pour mesurer un courant électrique dans un conducteur entouré par la bobine, la bobine comprenant au moins une boucle géométriquement fermée. Dans un mode de réalisation, chaque boucle comprend un conducteur entrant, un conducteur sortant et un conducteur intermédiaire définissant une boucle qui s'incurve et se croise sur lui-même. Dans un mode de réalisation, la bobine comprend une pluralité de boucles géométriquement fermées qui sont électriquement interconnectées. Dans un mode de réalisation, la bobine comprend une première boucle, une boucle terminale et au moins une boucle intermédiaire entre la première boucle et la boucle terminale, des boucles adjacentes étant électriquement interconnectées. Selon un second aspect de l'invention, il est proposé un procédé de construction d'une bobine de mesure de courant électrique du type décrit ci-dessus.
PCT/IB2009/007107 2008-10-11 2009-10-12 Bobine de mesure de courant électrique WO2010041139A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
ZA2011/01839A ZA201101839B (en) 2008-10-11 2011-03-10 Electrical current measuring coil

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ZA200805076 2008-10-11
ZA2008/05076 2008-10-11

Publications (1)

Publication Number Publication Date
WO2010041139A1 true WO2010041139A1 (fr) 2010-04-15

Family

ID=41404485

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2009/007107 WO2010041139A1 (fr) 2008-10-11 2009-10-12 Bobine de mesure de courant électrique

Country Status (2)

Country Link
WO (1) WO2010041139A1 (fr)
ZA (1) ZA201101839B (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8681469B2 (en) 2011-03-22 2014-03-25 General Electric Company Circuit protection device for use in medium and high voltage environments
DE102016124167A1 (de) 2016-12-13 2018-06-14 Dr. Ing. H.C. F. Porsche Aktiengesellschaft Rogowski-Stromsensor mit aktiver Kapazitätskompensation
WO2020076531A1 (fr) * 2018-10-12 2020-04-16 S&C Electric Company Interrupteur par défaut de taille réduite

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2471034A1 (fr) * 1979-12-04 1981-06-12 Merlin Gerin Capteur d'intensite a support souple deformable et son procede de fabrication
GB2088568A (en) * 1980-11-14 1982-06-09 Central Electr Generat Board A transducer for an alternating current measuring device
JPS585668A (ja) * 1981-06-30 1983-01-13 Fujitsu Ltd 検出コイル
US20030160603A1 (en) * 2002-02-27 2003-08-28 Kojovic Ljubomir A. Measuring current through an electrical conductor
WO2005103737A1 (fr) * 2004-04-24 2005-11-03 Werner Zumbrunn Capteur de courants alternatifs

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2471034A1 (fr) * 1979-12-04 1981-06-12 Merlin Gerin Capteur d'intensite a support souple deformable et son procede de fabrication
GB2088568A (en) * 1980-11-14 1982-06-09 Central Electr Generat Board A transducer for an alternating current measuring device
JPS585668A (ja) * 1981-06-30 1983-01-13 Fujitsu Ltd 検出コイル
US20030160603A1 (en) * 2002-02-27 2003-08-28 Kojovic Ljubomir A. Measuring current through an electrical conductor
WO2005103737A1 (fr) * 2004-04-24 2005-11-03 Werner Zumbrunn Capteur de courants alternatifs

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
KARRER N ET AL: "A NEW CURRENT PROBE WITH A WIDE BANDWIDTH", 8TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS. LAUSANNE, CH, SEPT. 7 - 9, 1999; [EPE . EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS], EPE ASSOCIATION, BRUSSELS, BE, vol. 8, 7 September 1999 (1999-09-07), pages 1 - 10, XP000883005, ISBN: 978-90-75815-04-7 *
KOJOVIC L A ED - INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS: "Split-core PCB rogowski coil designs and applications for protective relaying", 2003 IEEE PES TRANSMISSION AND DISTRIBUTION CONFERENCE. CONFERENCE PROCEEDINGS. DALLAS, TX, SEPT. 7 - 12, 2003; [IEEE/PES TRANSMISSION AND DISTRIBUTION CONFERENCE AND EXPOSITION], NEW YORK, NY : IEEE, US, vol. 1, 7 September 2003 (2003-09-07), pages 269 - 273, XP010725140, ISBN: 978-0-7803-8110-0 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8681469B2 (en) 2011-03-22 2014-03-25 General Electric Company Circuit protection device for use in medium and high voltage environments
DE102016124167A1 (de) 2016-12-13 2018-06-14 Dr. Ing. H.C. F. Porsche Aktiengesellschaft Rogowski-Stromsensor mit aktiver Kapazitätskompensation
US10345342B2 (en) 2016-12-13 2019-07-09 Dr. Ing. H.C. F. Porsche Aktiengesellschaft Rogowski current with active capacitance compensation
WO2020076531A1 (fr) * 2018-10-12 2020-04-16 S&C Electric Company Interrupteur par défaut de taille réduite
AU2019357876B2 (en) * 2018-10-12 2021-02-18 S&C Electric Company Reduced size fault interrupter

Also Published As

Publication number Publication date
ZA201101839B (en) 2011-11-30

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