EP0927357A1 - Detecteur pour mesurer l'intensite et/ou la tension d'un courant - Google Patents

Detecteur pour mesurer l'intensite et/ou la tension d'un courant

Info

Publication number
EP0927357A1
EP0927357A1 EP97933623A EP97933623A EP0927357A1 EP 0927357 A1 EP0927357 A1 EP 0927357A1 EP 97933623 A EP97933623 A EP 97933623A EP 97933623 A EP97933623 A EP 97933623A EP 0927357 A1 EP0927357 A1 EP 0927357A1
Authority
EP
European Patent Office
Prior art keywords
light
medium
fluorescent
measuring light
measuring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP97933623A
Other languages
German (de)
English (en)
Inventor
Thomas Bosselmann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
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 Siemens AG filed Critical Siemens AG
Publication of EP0927357A1 publication Critical patent/EP0927357A1/fr
Ceased legal-status Critical Current

Links

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
    • G01R15/24—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices
    • G01R15/247—Details of the circuitry or construction of devices covered by G01R15/241 - G01R15/246
    • 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
    • G01R15/24—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices
    • G01R15/245—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices using magneto-optical modulators, e.g. based on the Faraday or Cotton-Mouton effect
    • G01R15/246—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices using magneto-optical modulators, e.g. based on the Faraday or Cotton-Mouton effect based on the Faraday, i.e. linear magneto-optic, effect

Definitions

  • the invention relates to a sensor for measuring the electric current and / or voltage according to the preamble of claim 1.
  • Sensors of the type mentioned are known and are interesting for energy measurement tasks. Such sensors are mostly used to measure the current strength and / or voltage of alternating current.
  • an external conventional temperature sensor can be arranged on the medium intended for the measurement, which measures the temperature of this medium directly.
  • the electrical current to be measured can then be determined using the material constant associated with this measured temperature.
  • the invention has for its object to provide a sensor of the type mentioned, in which the temperature dependence of the material constant can be taken into account without an external temperature sensor.
  • the temperature associated with a certain temperature of the optically transparent medium and for determining of the current intensity and / or voltage determined specific material constant determined by determining the decay time of the fluorescence light generated in the fluorescent substance by the intensity-modulated excitation light.
  • the sensor according to the invention is particularly suitable for optically transparent media in which, apart from the temperature dependence of the optical material constants of this medium, no further temperature-dependent effect occurs.
  • This also applies in particular to a magneto-optical sensor according to claim 2, in which measurements are carried out in the optically transparent medium with the aid of the Faraday effect and the optical material constant of this medium is the Verdet constant.
  • temperature-dependent effects are, for example, linear and circular birefringence effects in the optically transparent medium, which change with the temperature and obscure the material-specific temperature dependence of the material constant through superimposition.
  • the fluorescent substance used in the sensor according to the invention in a light path of the measurement light generated by the measurement light source through the specific medium from the measurement light source and to couple the excitation light generated by the excitation light source into the light path of the measurement light and the fluorescent substance on this light path to forward (claim 4). This simplifies the construction of the sensor according to the invention.
  • the reflection arrangement has the effect that a temperature dependency of this linear birefringence is just being compensated for.
  • a sensor according to the invention which is suitable for an optically transparent medium in the form of such a fiber in a reflection arrangement is a sensor according to claim 4 which has the features of claim 5.
  • the requirements for the temperature measurement are advantageously relatively low in the sensor according to the invention, an accuracy of at most 1 ° C is sufficient.
  • the invention is not limited to magneto-optical sensors, but can also be applied to electro-optical sensors, for example sensors in which measurements are carried out in the optically transparent medium with the aid of the Pockels effect.
  • the figure shows a schematic representation of an exemplary sensor according to the invention, generally designated 1.
  • the exemplary sensor 1 is a magneto-optical sensor known per se for measuring the current intensity I of an electrical current i carried in an electrical conductor 2 on the basis of the Faraday effect.
  • the sensor 1 consists of the optically transparent medium 3 intended for the measurement in the form of a coil surrounding the conductor 2 in a number N turns of a highly twisted LoBi or Spun HiBi fiber 30 made of glass.
  • the material constant of the glass material of the fiber 30 of the coil 3 which is decisive for the Faraday effect is the Verdet constant V, which depends on the temperature T of the coil 3.
  • the coil 3 is arranged in the electromagnetic field F, which is generated by the current i flowing in the electrical conductor 2 and surrounds this conductor 2.
  • Measuring light L of a certain linear polarization p is sent through the fiber 30 of the coil 3 and the linear polarization p undergoes a polarization change ⁇ p in the form of a rotation of the polarization plane of the linear polarization p by a certain angle of rotation ⁇ as it passes through the fiber 30 of the coil 3 , of the Verdet constant V of the material of the fiber 30 of this coil 3, which is dependent on the temperature T of the coil 3, and the field strength H of the electromagnetic field F generated by the current i, and moreover of the length of the fiber in the electromagnetic field F. 30 of the coil 3, ie depends on the number N of turns of the coil 3.
  • the measuring light L of the determined linear polarization p is generated by a measuring light source 4, which is, for example, a laser diode.
  • the measurement light L generated by the measurement light source 4 is fed to an end 301 of the fiber 30 of the coil 3 on a light path 31.
  • Part of the light path 31 is, for example, an optical fiber 30_ optically coupled to this one end 301 of the fiber 30 of the coil 3, which optical fiber 30_ can be the same fiber as the fiber 30 of the coil 3 and can form a piece with this fiber 30.
  • a reflector 9 Opposite the other end 302 of the fiber 30 of the fiber coil 3, from which the measuring light L coupled into the coil 3 via the one end 301 is coupled out of the coil 3 after passing through the coil 3 in the direction from the one end 301 to the other end 302 , a reflector 9 is arranged.
  • This reflector 9 reflects the measuring light L coupled out from the other end 302 back to the other end 302, so that the reflected light L at this other end 302 is coupled back into the fiber 30 of the coil 3 and the coil 3 in the opposite direction passes from the other end 302 to one end 301. From one end 301, the reflected light L returns to the light path 31 in which it spreads in the opposite direction to the light L.
  • the reflector 9 realizes a reflection arrangement coil 3, in which a linear birefringence which has arisen in the fiber 30 of the coil 3 independently of the Faraday effect is compensated by an induced circular birefringence, but the polarization change ⁇ p of the linear polarization caused by the Faraday effect p of the measuring light L due to the double passage of the measuring light L through the coil 3 is equal to twice the single passage through the coil 3.
  • the back-reflected measuring light L which has returned to the light path 31 and has the linear polarization p + ⁇ p changed by ⁇ p, is coupled out of this light path 31 at a coupler 32 arranged in the light path 31 and a measuring light
  • the coupler 32 must be non-polarizing. This means that the coupler 32 may not change the polarization p or p + ⁇ p of the supplied and back-reflected measurement light L essentially, ie at most by a predetermined, permissible slight deviation.
  • the coupler 32 can have, for example, a non-polarizing beam splitter or fiber coupler.
  • the coupler 32 consists, for example, of a beam splitter 321 arranged between two optical lenses 322 and 323, to which the measuring light L generated by the measuring light source 4 is fed on a section 311 of the light path 31.
  • the beam splitter 321 deflects the measurement light L to the lens 322, a portion of the measurement light L that has passed through the beam splitter 321 not
  • the lens 322 couples the deflected measuring light L into the fiber 30 ] .
  • the back-reflected measuring light L which has returned to the light path 31 is fed through the lens 322 and the beam splitter 321 to the lens 323, which couples this measuring light L, for example, into an optical fiber 33] which is part of a light path 33 on which the measuring light L from the coupler 32 to the measuring light evaluation device 5 for evaluation.
  • a portion of the reflected light L which is deflected by the beam splitter 321 is not evaluated.
  • Lenses 322 and 323 are preferably gradient lenses.
  • a quantity ⁇ is obtained in the measuring light evaluation device 5, which corresponds to the change in polarization ⁇ p which the measuring light L which has passed twice through the coil 3 has undergone.
  • the current intensity I of the current i in the conductor 2 can be determined together with the length of the fiber 30 of the coil 3 given by the number of turns N, for example.
  • the measuring light evaluation device 5 can have, for example, a polarization beam splitter 50, for example in the form of a Wollaston prism, in which the change in polarization ⁇ p of the linear polarization p is analyzed.
  • the optical power i s of a certain fixed emerges from the prism 50 Component p s of the supplied linear polarization p + Ap and the optical power I w a s p to this component perpendicular component of this polarization p w p + Ap from.
  • a fluorescent substance 6 is arranged so close to the coil 3 that it always has essentially the same temperature T as the coil 3, wherein in the fluorescent substance 6 by irradiation of excitation light L1 a radiation of fluorescent light L2 can be excited, the intensity 12 of which decays after the end of irradiation of excitation light L1 in a certain decay time ⁇ t, the fluorescent substance 6 being selected such that the decay time ⁇ t defines the temperature T of the fluorescent light Substance 6 depends.
  • intensity-modulated excitation light L1 is emitted into this substance 6, which is generated by a modulatable excitation light source 7, which has a laser diode, for example.
  • the excited fluorescent light L2 is fed to a fluorescent light evaluation device 8 for determining the decay time ⁇ t of the fluorescent light L2 excited by the intensity-modulated excitation light L1. From the determined decay time ⁇ t, the temperature T of the fluorescent substance 6 belonging to this determined decay time ⁇ t and the value Veff of the Verdet constant V belonging to this temperature T are to be determined, with which the electric current intensity I can be determined.
  • the fluorescent light evaluation device 8 has, for example, an optoelectric converter 81 for converting the intensity 12 of the fluorescent light L2 into a corresponding electrical intensity signal and an evaluation unit 82 in which the decay duration ⁇ t of the fluorescent light L2 is determined from the electrical intensity signal which decays in accordance with the optical intensity 12 .
  • the excitation light L1 is to be modulated, for example i pulse, rectangular, sinusoidal modulation.
  • a particularly simple evaluation method uses pulse-shaped modulation, in which the excitation light L1 consists of successive pulses and the fluorescence is excited cyclically, measures the decaying intensity 12 of the fluorescent light L2 over time t and determines the decay duration ⁇ t.
  • the temperature T of the fluorescent substance 6 associated with this specific duration ⁇ t can be determined, for example, from the specific decay duration ⁇ t. From the temperature T determined, the value V e ff of the Verdet constant V belonging to this temperature T can be calculated, with which the current intensity I through
  • I ⁇ / (NV eff ) can be calculated, for example in the signal processor 53.
  • the timing between the excitation light source 7 and the fluorescent light evaluation device 8 can take place via a trigger and feedback line 78 connecting this source 7 and this device 8.
  • the fluorescent substance 6 is arranged in the light path 31 of the measuring light L leading from the measuring light source 4 through the coil 3, and the excitation light L 1 generated by the excitation light source 7 is coupled into the light path 31 of the measuring light L and on this light path 31 fed fluorescent substance 6, it being advantageous if the fluorescent substance 6 is arranged between the coil 3 and the reflector 9.
  • the excitation light L1 is coupled into the light path 31 by an optical coupler 34, for example a beam splitter, arranged in the section 311 between the measurement light source 4 and the coupler 32 of the light path 31 of the measurement light L.
  • This coupler 34 must be non-polarizing for the polarization of the measuring light L generated by the light source 4.
  • the fluorescent light L2 generated by the fluorescent substance 6 is transmitted on the light path 31 of the measuring light L, i.e. guided on the fiber 30 through the coil 3 and after passing through the coil 3 out of the light path 31 of the measuring light L and coupled into the fluorescent light evaluation device 8.
  • This demultiplexer 35 which is arranged, for example, in the light path 33 leading from the coupler 32 to the measurement light evaluation device 8. can be net and which only couples the fluorescent light L2 out of the light path 33 and feeds the fluorescent light evaluation device 8.
  • This demultiplexer 35 must not significantly change the polarization of the measurement light supplied to the measurement light evaluation device 5.
  • the coupler 32 must be wavelength-independent for a wavelength range comprising the wavelength ⁇ 2 of the fluorescent light L2 and the wavelength ⁇ of the measurement light L. Since the wavelength ⁇ l of the excitation light Ll is generally different from the wavelength ⁇ of the measurement light L, the coupler 34 and the coupler 32 should be wavelength-independent for a wavelength range comprising the wavelength ⁇ l of the excitation light L1 and the wavelength ⁇ of the measurement light L.
  • the intensity II and wavelength ⁇ l of the excitation light Ll are expediently chosen so that the excitation light Ll is completely absorbed by the fluorescent substance 6, so that no excitation light Ll comes from this substance 6. If this is not the case, a measure for separating the excitation light L 1 from the measurement light L and fluorescent light L 2 must be provided in the exemplary sensor 1, which can consist, for example, in a wavelength-selective optical filter device if the wavelength ⁇ 1 of the excitation light L 1 is both from the Wavelength ⁇ of the measuring light L as well as the wavelength ⁇ 2 of the fluorescent light L2 is different, which is normally the case.
  • the fluorescent substance 6 can be in the form of a crystal. Crystals are mainly used which are treated with rare earth ions such as neodymium, erbium, terbium or the transition metals such as chromium or manganese (see Journ. Of Lightw. Techn., Vol. 7, No. 12, 12/1989, pages 2084 bis 2095).
  • the measurement light L and excitation light L 1 are expediently coupled out from the other end 302 fiber 30 into an optical lens 303, preferably a gradient lens, which bundles the decoupled measurement light L and excitation light L 1.
  • the crystal 6 is arranged between that of the lens 303 and the reflector 9 and is irradiated by the bundled measuring light L, while the fluorescent light L2 is generated in the crystal 6 by absorption of the excitation light L1.
  • the lens 303 focuses the bundled measuring light L reflected by the reflector 9 and a large part of the fluorescent light L2 onto the other end 302 of the fiber 30 and couples these light L and L2 into this fiber 30.
  • the fluorescent substance 6 can also be in the form of a fluorescent optical fiber which is doped with a dopant which generates the fluorescence, for example erbium. Erbium-doped fibers have been used as optical amplifiers.
  • the fluorescent fiber can be a section of the fiber of a coil. In the exemplary sensor 1, the fluorescent fiber 6 is expediently an end section 302 of the fiber 30 of the coil 3 which contains the other end 302.
  • the optical end is between the other end 302 of the fiber 30 and the reflector 9 Lens 303 is arranged, which bundles the measuring light L and fluorescent light L2 coupled out from the other end 302 of the fiber 30 and focuses the bundled measuring light L and fluorescent light L2 reflected by the reflector 9 again onto the other end 302 of the fiber 30 and couples it into this fiber 30 .
  • the invention has been described in connection with a magneto-optical sensor for measuring the current intensity I of an electrical current i flowing in a conductor 2.
  • a magneto-optical sensor for measuring the current intensity I of an electrical current i flowing in a conductor 2.
  • it can be applied analogously to an electro-optical sensor for measuring the electrical voltage U applied to the conductor 2, for example an AC voltage.
  • the sor in the optically transparent medium the electrical field strength of the electrical or electromagnetic field generated by the voltage U, for example with the help of the Pockels effect.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Magnetic Variables (AREA)
  • Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)

Abstract

Détecteur magnéto-optique (1) pour mesurer l'intensité du courant (I) à l'aide de la constante de Verdet (V) dépendante de la température d'une bobine de fibres (3) disposée dans un champ électromagnétique (F) généré par le courant électrique (i). La durée du déclin (Δt), lié à la température, de la fluorescence d'une matière fluorescente (6) placée à proximité de la bobine, la température correspondante (T) de la bobine et la valeur de la constante de Verdet (V) correspondant à cette température (Veff) permettent de déterminer l'intensité du courant. Ce procédé peut être appliqué dans des détecteurs de courant et de tension.
EP97933623A 1996-09-19 1997-07-10 Detecteur pour mesurer l'intensite et/ou la tension d'un courant Ceased EP0927357A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19638456 1996-09-19
DE19638456 1996-09-19
PCT/DE1997/001459 WO1998012565A1 (fr) 1996-09-19 1997-07-10 Detecteur pour mesurer l'intensite et/ou la tension d'un courant

Publications (1)

Publication Number Publication Date
EP0927357A1 true EP0927357A1 (fr) 1999-07-07

Family

ID=7806258

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97933623A Ceased EP0927357A1 (fr) 1996-09-19 1997-07-10 Detecteur pour mesurer l'intensite et/ou la tension d'un courant

Country Status (4)

Country Link
US (1) US6140634A (fr)
EP (1) EP0927357A1 (fr)
CA (1) CA2266596A1 (fr)
WO (1) WO1998012565A1 (fr)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ATE234471T1 (de) 1998-12-22 2003-03-15 Siemens Ag Verfahren und anordnung zur optischen erfassung eines elektrischen stroms über lichtsignale mit unterschiedlicher wellenlänge
JP2004093257A (ja) * 2002-08-30 2004-03-25 Oki Electric Ind Co Ltd 光センサユニット
US7786719B2 (en) * 2005-03-08 2010-08-31 The Tokyo Electric Power Company, Incorporated Optical sensor, optical current sensor and optical voltage sensor
US7655900B2 (en) * 2005-03-08 2010-02-02 The Tokyo Electric Power Company, Incorporated Intensity modulation type optical sensor and optical current/voltage sensor
CN100498298C (zh) * 2006-04-19 2009-06-10 中国科学院半导体研究所 变温显微磁光光谱系统
US20110052115A1 (en) * 2009-08-27 2011-03-03 General Electric Company System and method for temperature control and compensation for fiber optic current sensing systems
CN102023141B (zh) * 2009-09-23 2012-08-22 中国科学院半导体研究所 具有灵活测量几何的变温显微磁光电测试系统
CN101806623B (zh) * 2010-04-07 2011-10-05 中国科学院半导体研究所 一种多功能反射式磁光光谱测量系统
CN102608380B (zh) * 2012-02-29 2013-12-11 曲阜师范大学 自感应光电混合式电流互感器
US10006944B2 (en) * 2012-07-19 2018-06-26 Gridview Optical Solutions, Llc. Electro-optic current sensor with high dynamic range and accuracy
US9632113B2 (en) * 2014-03-13 2017-04-25 Ofs Fitel, Llc Few-moded fiber for sensing current
CN106291040B (zh) * 2016-07-26 2018-12-18 胡朝年 磁光电流互感器
RU2686452C1 (ru) * 2018-05-31 2019-04-25 Федеральное государственное бюджетное учреждение науки Институт проблем управления им. В.А. Трапезникова Российской академии наук Сверхвысокочастотный измеритель электрических величин

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3202089C2 (de) * 1982-01-23 1985-01-17 Fa. Carl Zeiss, 7920 Heidenheim Faseroptischer Temperatursensor
JPH0670653B2 (ja) * 1989-03-31 1994-09-07 日本碍子株式会社 光温度・電気量測定装置
DE4312183A1 (de) * 1993-04-14 1994-10-20 Siemens Ag Optisches Meßverfahren zum Messen eines elektrischen Wechselstromes mit Temperaturkompensation und Vorrichtung zur Durchführung des Verfahrens
US6043648A (en) * 1996-06-14 2000-03-28 Siemens Aktiengesellschaft Method for temperature calibration of an optical magnetic field measurement array and measurement array calibrated by the method

Non-Patent Citations (1)

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Title
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Also Published As

Publication number Publication date
US6140634A (en) 2000-10-31
WO1998012565A1 (fr) 1998-03-26
CA2266596A1 (fr) 1998-03-26

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