JPH06242149A - Optical current sensor - Google Patents
Optical current sensorInfo
- Publication number
- JPH06242149A JPH06242149A JP5028160A JP2816093A JPH06242149A JP H06242149 A JPH06242149 A JP H06242149A JP 5028160 A JP5028160 A JP 5028160A JP 2816093 A JP2816093 A JP 2816093A JP H06242149 A JPH06242149 A JP H06242149A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- polarizer
- optical fiber
- analyzer
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 17
- 239000010409 thin film Substances 0.000 claims abstract description 40
- 239000013307 optical fiber Substances 0.000 claims abstract description 30
- 230000000694 effects Effects 0.000 claims description 13
- 238000010030 laminating Methods 0.000 abstract 1
- 238000005549 size reduction Methods 0.000 abstract 1
- 239000004020 conductor Substances 0.000 description 8
- 230000010287 polarization Effects 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005253 cladding Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000002223 garnet Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
Landscapes
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、電路の電流を検出す
る光式電流センサに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical current sensor for detecting a current in an electric circuit.
【０００２】[0002]
【従来の技術】光式電流センサは通常、光源と受光部と
の間に、光ファイバ，コリメータ，偏光子，磁気光学効
果素子，検光子，コリメータ，光ファイバの順に配列し
た光経路を設け、磁気光学効果素子を電線の外周に配設
している。電線に電流が流れると、電線の周囲に磁界が
発生し、磁気光学効果素子の偏光面が磁界の強さに比例
して回転する。一方、光源よりランダムな光が光ファイ
バおよびコリメータを通して偏光子に入射すると直線偏
光が取り出される。この直線偏光が磁気光学効果素子に
入射し、偏光子に対して４５度回転した検光子に入射す
ると、磁界の強さに比例した強さの光が得られ、コリメ
ータおよび光ファイバを通して受光部に入射し電気信号
に変換される。2. Description of the Related Art An optical current sensor is usually provided with an optical path in which an optical fiber, a collimator, a polarizer, a magneto-optical effect element, an analyzer, a collimator, and an optical fiber are arranged in this order between a light source and a light receiving section. The magneto-optical effect element is arranged on the outer circumference of the electric wire. When a current flows through the electric wire, a magnetic field is generated around the electric wire, and the plane of polarization of the magneto-optical effect element rotates in proportion to the strength of the magnetic field. On the other hand, when random light from the light source enters the polarizer through the optical fiber and the collimator, linearly polarized light is extracted. When this linearly polarized light enters the magneto-optical effect element and then enters the analyzer rotated by 45 degrees with respect to the polarizer, light having an intensity proportional to the strength of the magnetic field is obtained, and is transmitted to the light receiving portion through the collimator and the optical fiber. It is incident and converted into an electric signal.
【０００３】電路の電流の大きさは磁界の強さに比例す
るので受光部の信号により電流の大きさが検出される。Since the magnitude of the current in the electric path is proportional to the strength of the magnetic field, the magnitude of the current can be detected by the signal from the light receiving section.
【０００４】[0004]
【発明が解決しようとする課題】しかし、この光式電流
センサは、そのセンサ部分のサイズが約３０×３０×１
０ｍｍと大きく、コネクタ部分を含めると５ｃｍ位の大
きさが必要であるため、電路の周囲の取付け場所やスペ
ースが大きくなり、たとえばガス絶縁開閉装置などにお
ける導体の導体間距離が１０ｃｍ程度の場所に挿入でき
ないという欠点があった。また光式電流センサを設置し
た際の美観もよくないという問題があった。However, the size of the sensor portion of this optical current sensor is about 30 × 30 × 1.
Since it is as large as 0 mm and needs to have a size of about 5 cm including the connector part, the installation place and space around the electric path become large. For example, in the place where the conductor-to-conductor distance in a gas-insulated switchgear is about 10 cm. There was a drawback that it could not be inserted. In addition, there is a problem that the aesthetic appearance when the optical current sensor is installed is not good.
【０００５】したがって、この発明の目的は、小形化が
可能な光式電流センサを提供することである。Therefore, an object of the present invention is to provide an optical current sensor which can be miniaturized.
【０００６】[0006]
【課題を解決するための手段】この発明の光式電流セン
サは、端面に薄膜偏光子を積層した第１の光ファイバ
と、端面に薄膜検光子を積層した第２の光ファイバと、
前記薄膜偏光子と前記薄膜検光子との間に介在された磁
気光学効果素子とを備えたものである。An optical current sensor according to the present invention comprises a first optical fiber having a thin film polarizer laminated on its end face, and a second optical fiber having a thin film analyzer laminated on its end face.
It is provided with a magneto-optical effect element interposed between the thin film polarizer and the thin film analyzer.
【０００７】[0007]
【作用】この発明の構成によれば、光が第１の光ファイ
バを通して薄膜偏光子に入射し直線偏光に変換される。
この直線偏光が磁気光学効果素子および薄膜検光子を透
過することにより、磁気光学効果素子は、電路の周囲の
磁界の大きさに比例した回転角に偏光面を回転している
ので、磁界の大きさに比例した強さの直線偏光を出射す
る。この直線偏光が第２の光ファイバを通して受光部に
入射し、磁界したがって電流の大きさに比例した信号を
検出する。According to the structure of the present invention, light is incident on the thin film polarizer through the first optical fiber and is converted into linearly polarized light.
By transmitting this linearly polarized light through the magneto-optical effect element and the thin film analyzer, the magneto-optical effect element rotates the polarization plane at a rotation angle proportional to the magnitude of the magnetic field around the electric path. Linearly polarized light having an intensity proportional to the intensity is emitted. This linearly polarized light enters the light receiving portion through the second optical fiber and detects a signal proportional to the magnitude of the magnetic field and thus the current.
【０００８】この場合、薄膜偏光子および薄膜検光子を
用いたため、小形化が可能となり、取付場所のスペース
を小さくでき、狭い間隔の導体間に挿入することが可能
となり、美観もよくなる。In this case, since the thin film polarizer and the thin film analyzer are used, the size can be reduced, the space at the mounting place can be reduced, and the conductors can be inserted between the conductors with a narrow interval, and the appearance can be improved.
【０００９】[0009]
【実施例】この発明の第１の実施例を図１ないし図５に
より説明する。すなわち、この光式電流センサは、第１
の光ファイバ１と、第２の光ファイバ２と、磁気光学効
果素子３とを有する。第１の光ファイバ１は端面に薄膜
偏光子６を積層している。実施例では第１の光ファイバ
１はマルチモードファイバを使用しており、図２に示す
ようにコア４とクラッド５を有する。また薄膜偏光子６
はたとえばラミポール（商品名）を使用し、コア径×３
０μｍ（厚さ）の大きさにして、図３に示すようにコア
４の端面に積層している。８はコア４を保護および固定
するためのフェルールである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. That is, this optical current sensor is
Optical fiber 1, second optical fiber 2, and magneto-optical effect element 3. The first optical fiber 1 has a thin film polarizer 6 laminated on its end face. In the embodiment, the first optical fiber 1 uses a multimode fiber and has a core 4 and a clad 5 as shown in FIG. Also, thin film polarizer 6
Uses, for example, Ramipol (trade name) and has a core diameter of 3
The size is set to 0 μm (thickness) and laminated on the end surface of the core 4 as shown in FIG. Reference numeral 8 is a ferrule for protecting and fixing the core 4.
【００１０】第２の光ファイバ２は、端面に薄膜検光子
７を薄膜偏光子６と４５度傾けて積層している。実施例
は第１の光ファイバ１における構成と同じにしている。
磁気光学効果素子３は、薄膜偏光子６と薄膜検光子７と
の間に介在されている。実施例では磁気光学結晶たとえ
ば厚さ２０μｍのＲＩＧ（希土類鉄ガーネット結晶）を
適用している。In the second optical fiber 2, a thin film analyzer 7 is laminated on the end face with the thin film polarizer 6 at an angle of 45 degrees. The embodiment has the same structure as that of the first optical fiber 1.
The magneto-optical effect element 3 is interposed between the thin film polarizer 6 and the thin film analyzer 7. In the embodiment, a magneto-optical crystal, for example, RIG (rare earth iron garnet crystal) having a thickness of 20 μm is applied.
【００１１】この光式電流センサは、図４（ａ）に示す
ようなランダムな光が光源より第１の光ファイバ１を通
して薄膜偏光子６に入射し、同図（ｂ）の直線偏光に変
換される。この直線偏光が磁気光学効果素子３および薄
膜検光子７を透過することにより、磁気光学効果素子は
同図（ｃ）のように電路の周囲の磁界の大きさに比例し
た回転角に偏光面を回転し、また薄膜検光子７は薄膜偏
光子６に対して４５度回転した位置に傾斜しているの
で、同図（ｄ）のように磁界の大きさに比例した強さの
光量を出射する。この直線偏光が第２の光ファイバ２を
通して受光部（図示せず）に入射し、磁界したがって電
流の大きさに比例した信号を検出する。In this optical current sensor, random light as shown in FIG. 4 (a) enters the thin film polarizer 6 from the light source through the first optical fiber 1 and is converted into the linearly polarized light shown in FIG. 4 (b). To be done. By transmitting this linearly polarized light through the magneto-optical effect element 3 and the thin film analyzer 7, the magneto-optical effect element changes the plane of polarization to a rotation angle proportional to the magnitude of the magnetic field around the electric path as shown in FIG. Since the thin film analyzer 7 is rotated and tilted at a position rotated by 45 degrees with respect to the thin film polarizer 6, a light amount having an intensity proportional to the magnitude of the magnetic field is emitted as shown in FIG. . This linearly polarized light enters the light receiving portion (not shown) through the second optical fiber 2 and detects a signal proportional to the magnitude of the magnetic field and thus the current.
【００１２】この実施例によれば、薄膜偏光子６および
薄膜検光子７を用いたため、小形化が可能となり、取付
場所のスペースを小さくでき、狭い間隔の導体間に挿入
することが可能となり、美観もよくなる。とくに、第１
の光ファイバ１の入射側と第２の光ファイバ２の出射側
の距離を１００μｍとすることができ、光の拡がりを押
えることができるので、コリメータを省略することが可
能になる。また全体として４．５φ×３０ｍｍ〜３．０
φ×２０ｍｍのサイズとすることができ、ほぼコードの
太さまで小形化することができる。したがって、導体間
距離が１０ｃｍ程度の隙間にも容易に設置することがで
きる。According to this embodiment, since the thin film polarizer 6 and the thin film analyzer 7 are used, the size can be reduced, the space for the mounting place can be reduced, and the conductors can be inserted between the conductors with a narrow interval. The aesthetics will also improve. Especially, the first
Since the distance between the entrance side of the optical fiber 1 and the exit side of the second optical fiber 2 can be set to 100 μm and the spread of light can be suppressed, the collimator can be omitted. Also, 4.5φ × 30 mm to 3.0 as a whole
The size can be φ × 20 mm, and the size can be reduced to almost the thickness of the cord. Therefore, it can be easily installed even in a gap having a conductor-to-conductor distance of about 10 cm.
【００１３】図５は、この実施例を電路導体に直付けし
リニアリティを測定した結果を示す。すなわち、この図
は定格８００Ａからその５％値である４０Ａまでの電流
に対する比誤差（％）のグラフＱ1 および位相角（分）
のグラフＱ2 であり、１％以内という良好な結果が得ら
れた。またＲＩＧを用いた光式電流センサは帯域１ＭＨ
ｚの広帯域化が可能である。FIG. 5 shows the result of measuring the linearity by directly mounting this embodiment on an electric circuit conductor. That is, this figure is a graph Q 1 of the ratio error (%) to the current from the rated 800 A to its 5% value of 40 A and the phase angle (min).
Is a graph Q 2 of , and a good result of 1% or less was obtained. In addition, the optical current sensor using RIG has a bandwidth of 1 MHz.
Wide band of z is possible.
【００１４】なお、薄膜偏光子６および薄膜検光子７は
クラッドの径の大きさでもよい。この発明の第２の実施
例を図６により説明する。すなわち、この光式電流セン
サは、薄膜偏光子６をコリメータまたは薄膜コリメータ
９を介して第１の光ファイバ１の端面に積層し、また薄
膜検光子７をコリメータまたは薄膜コリメータ９を介し
て第２の光ファイバ２に積層している。その他は第１の
実施例と同様である。The thin film polarizer 6 and the thin film analyzer 7 may have a cladding diameter. A second embodiment of the present invention will be described with reference to FIG. That is, in this optical current sensor, the thin film polarizer 6 is laminated on the end face of the first optical fiber 1 via the collimator or the thin film collimator 9, and the thin film analyzer 7 is arranged via the collimator or the thin film collimator 9 to the second side. Is laminated on the optical fiber 2. Others are the same as those in the first embodiment.
【００１５】[0015]
【発明の効果】この発明の光式電流センサによれば、薄
膜偏光子および薄膜検光子を用いたため、小形化が可能
となり、取付場所のスペースを小さくでき、狭い間隔の
導体間に挿入することが可能となり、美観もよくなると
いう効果がある。According to the optical current sensor of the present invention, since the thin film polarizer and the thin film analyzer are used, the size can be reduced, the space for the mounting place can be reduced, and the thin film polarizer can be inserted between the conductors having a narrow interval. It is possible to improve the aesthetics.
【図１】この発明の第１の実施例の接続前の状態の側面
図である。FIG. 1 is a side view of a first embodiment of the present invention before connection.
【図２】光ファイバの端面を示す部分斜視図である。FIG. 2 is a partial perspective view showing an end face of an optical fiber.
【図３】薄膜偏光子を積層した状態の部分斜視図であ
る。FIG. 3 is a partial perspective view showing a state where thin film polarizers are laminated.
【図４】光式電流センサを通過する光の偏光状態を説明
する説明図である。FIG. 4 is an explanatory diagram illustrating a polarization state of light passing through an optical current sensor.
【図５】電流に対する比誤差および位相角のグラフであ
る。FIG. 5 is a graph of ratio error versus phase angle versus current.
【図６】第２の実施例の接続前の側面図である。FIG. 6 is a side view of the second embodiment before connection.
１ 第１の光ファイバ ２ 第２の光ファイバ ３ 磁気光学効果素子 ６ 薄膜偏光子 ７ 薄膜検光子 1 1st optical fiber 2 2nd optical fiber 3 Magneto-optical effect element 6 Thin film polarizer 7 Thin film analyzer
Claims (1)
ァイバと、端面に薄膜検光子を積層した第２の光ファイ
バと、前記薄膜偏光子と前記薄膜検光子との間に介在さ
れた磁気光学効果素子とを備えた光式電流センサ。1. A first optical fiber having a thin film polarizer laminated on an end face, a second optical fiber having a thin film analyzer laminated on an end face, and the first optical fiber interposed between the thin film polarizer and the thin film analyzer. An optical current sensor having a magneto-optical effect element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5028160A JPH06242149A (en) | 1993-02-17 | 1993-02-17 | Optical current sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5028160A JPH06242149A (en) | 1993-02-17 | 1993-02-17 | Optical current sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06242149A true JPH06242149A (en) | 1994-09-02 |
Family
ID=12241008
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5028160A Pending JPH06242149A (en) | 1993-02-17 | 1993-02-17 | Optical current sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06242149A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5699461A (en) * | 1994-12-12 | 1997-12-16 | Matsushita Electric Industrial Co., Ltd. | Optical fiber sensors and method for making the same |
| KR100428891B1 (en) * | 2001-12-21 | 2004-04-29 | 재단법인 포항산업과학연구원 | Contactless current measuring apparatus using laser |
-
1993
- 1993-02-17 JP JP5028160A patent/JPH06242149A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5699461A (en) * | 1994-12-12 | 1997-12-16 | Matsushita Electric Industrial Co., Ltd. | Optical fiber sensors and method for making the same |
| KR100428891B1 (en) * | 2001-12-21 | 2004-04-29 | 재단법인 포항산업과학연구원 | Contactless current measuring apparatus using laser |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100248128B1 (en) | Optical current transformer | |
| KR0173672B1 (en) | Fiber optic device for measuring current strength | |
| EP1261880B1 (en) | Faraday-effect current sensor with improved vibration response | |
| US11435415B2 (en) | Magnetic sensor element and magnetic sensor device | |
| JPH06242149A (en) | Optical current sensor | |
| JP3611975B2 (en) | Optical CT with failure judgment function | |
| KR900010396A (en) | Fiber optic rotation sensor | |
| JPS59145977A (en) | Magnetic field measuring device | |
| JPS59107273A (en) | Photocurrent and magnetic field sensor | |
| JPH10319051A (en) | Current measuring device | |
| JP2000111586A (en) | Current measuring device | |
| JP3271117B2 (en) | Current sensor | |
| JPS61107169A (en) | Current detector using optical fiber | |
| JP3415972B2 (en) | Optical fiber sensor and polarizer unit | |
| JPH0674979A (en) | Optical current sensor | |
| JPH0743661Y2 (en) | Optical magnetic field sensor mounting device | |
| Willsch et al. | Vibration compensation for a glass ring type magnetooptic current sensor | |
| JP4215313B2 (en) | Light current transformer | |
| JPH0797116B2 (en) | Fiber optic current sensor | |
| JPH08304469A (en) | Current sensor | |
| JPH06243735A (en) | Electric wire | |
| JP3268587B2 (en) | Current measuring method and measuring device | |
| JPH03216558A (en) | Photocurrent sensor | |
| KR0183281B1 (en) | Ac current measurement device using sagnac optical fiber current sensor | |
| JP2003130896A (en) | Current measuring device |