JPH05172854A - Measurement of electric current by photomagnetic field sensor - Google Patents
Measurement of electric current by photomagnetic field sensorInfo
- Publication number
- JPH05172854A JPH05172854A JP3354818A JP35481891A JPH05172854A JP H05172854 A JPH05172854 A JP H05172854A JP 3354818 A JP3354818 A JP 3354818A JP 35481891 A JP35481891 A JP 35481891A JP H05172854 A JPH05172854 A JP H05172854A
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- Prior art keywords
- current
- magnetic field
- measured
- field sensor
- optical
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はファラデ−効果を利用し
た光磁界センサにより、開閉装置、断路器、電力ケ−ブ
ル等の導体に流れる電流を測定する方法に関し、特に、
低電流から大電流までの広い範囲の電流値の測定や、導
体数が２以上ある多導体の電流測定に使用するのに適す
るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a current flowing through a conductor such as a switchgear, a disconnector and a power cable by an optical magnetic field sensor utilizing the Faraday effect, and more particularly,
It is suitable for use in measuring a wide range of current values from low current to large current, and for measuring the current of multiple conductors having two or more conductors.
【０００２】[0002]
【従来の技術】開閉装置、断路器、電力ケ−ブル等の導
体に流れる電流を測定するには、従来は、図４に示すよ
うに被測定導体１１の所定位置にファラデー効果を利用
した光磁界センサ１２を配置し、その光磁界センサ１２
の光信号を電気信号に変換し、処理して行なっていた。2. Description of the Related Art Conventionally, in order to measure a current flowing through a conductor such as a switchgear, a disconnecting switch, and a power cable, an optical device utilizing the Faraday effect is provided at a predetermined position of a conductor 11 to be measured as shown in FIG. The magnetic field sensor 12 is arranged and the optical magnetic field sensor 12 is arranged.
The optical signal of is converted into an electric signal and processed.
【０００３】光磁界センサ１２は発光部２０、受光部２
１等からなる検出器２３、ファラデ−素子等からなる光
センサ部２４、この光センサ部２４と前記検出器２３を
結ぶ光ファイバ２５からなる。前記光センサ部２４では
図５に示すように偏光子２６によって直線偏光された光
波がファラデ−素子２７に入射され、その光波はファラ
デ−素子２７に印加されている磁界（被測定導体１１に
流れる電流によって生じた磁界）の強度に応じたファラ
ーデー回転を起こし、この光波が検光子２８によって光
の強度に変換され、光ファイバ２５を通して前記受光部
２１に至る。The optical magnetic field sensor 12 includes a light emitting section 20 and a light receiving section 2.
It comprises a detector 23 composed of 1 etc., an optical sensor section 24 composed of a Faraday element and the like, and an optical fiber 25 connecting the optical sensor section 24 and the detector 23. In the optical sensor section 24, as shown in FIG. 5, the light wave linearly polarized by the polarizer 26 is incident on the Faraday element 27, and the light wave is applied to the Faraday element 27 (magnetic field flowing to the conductor 11 to be measured). Faraday rotation is caused according to the intensity of the magnetic field generated by the electric current, and this light wave is converted into light intensity by the analyzer 28 and reaches the light receiving portion 21 through the optical fiber 25.
【０００４】ここで入射光の電気ベクトルの大きさを
Ｅ、磁界をＨ、偏光子Ｅと検光子Ｈのなす角をθ0 、フ
ァラデー回転角をθ、ベルデ定数をＶD 、有効光路長を
ｌとすると、検光子Ｈを透過する光強度Ｐは次式で表さ
れる。 Ｐ＝｜Ｅcos(θ0 ーθ）ｅiwt ｜2 ＝Ｅ2 cos2（θ0 ーθ） ＝Ｅ2 ／２｛１＋cos ２（θ0 ーθ）｝ 但しθ＝ＶD ＨｌHere, the magnitude of the electric vector of the incident light is E, the magnetic field is H, the angle between the polarizer E and the analyzer H is θ 0 , the Faraday rotation angle is θ, the Verdet constant is V D , and the effective optical path length is Assuming l, the light intensity P transmitted through the analyzer H is expressed by the following equation. P = | Ecos (θ 0 over θ) e iwt | 2 = E 2 cos 2 (θ 0 over θ) = E 2/2 { 1 + cos 2 (θ 0 over theta)} where θ = V D Hl
【０００５】また、従来は特に低電流を高精度に測定す
る場合とか、外乱ノイズを除去する必要がある場合等
は、図６のように被測定導体１１の外周にギャップ付き
磁性コア１３を被せ、同磁性コア１３のギャップ中に前
記光磁界センサ１２のセンサ部２４を設置し、次式に基
ずいて電流値を測定していた。 Ｈa 〜Ｉ／ｌ 但しｌ：ギャップ長Further, conventionally, when a low current is measured with high accuracy, or when disturbance noise needs to be removed, a magnetic core 13 with a gap is covered on the outer circumference of the conductor 11 to be measured as shown in FIG. The sensor section 24 of the optical magnetic field sensor 12 was installed in the gap of the magnetic core 13 and the current value was measured based on the following equation. H a ~I / l However l: gap length
【０００６】また、１５４ｋＶ、２７５ｋＶ等の超高電
圧を伝送する超高圧線は導体径が太いので、送電線を変
電所に引込む場合は細い多導体に分岐して引込まざるを
得ない。この場合、送電線の分岐前で電流測定しようと
すると導体径が大きいため、センサ、特に、磁性コアが
非常に大きくなってしまう。しかもそのセンサを鉄塔の
上に取付けなければならないので、設置が困難である。
このように複数本の導体（多導体）を用いて通電する場
合は、図４、図６のいずれの電流測定方法により電流測
定するにしても、分岐された各導体（多導体）に前記光
磁界センサ１２を設置して各導体１１の電流を測定し、
その和を電気的にとって分岐前の送電線の電流を測定し
ていた。Further, since the conductor diameter of the ultra-high voltage line for transmitting ultra-high voltage such as 154 kV and 275 kV is large, when the transmission line is drawn into the substation, there is no choice but to branch it into a thin multiconductor. In this case, if an attempt is made to measure the current before the branch of the power transmission line, the diameter of the conductor is large, so that the sensor, especially the magnetic core, becomes very large. Moreover, the sensor must be mounted on the steel tower, which makes installation difficult.
When a plurality of conductors (multiconductors) are used to conduct electricity in this way, no matter which of the current measurement methods of FIG. 4 and FIG. A magnetic field sensor 12 is installed to measure the current of each conductor 11,
The sum was electrically used to measure the current of the transmission line before branching.
【０００７】[0007]
【発明が解決しようとする課題】前記した従来の測定方
法では次のような問題があった。 ギャップ付き磁性コアを使用しない図４の場合は低
電流側の測定精度が落ちる。 ギャップ付き磁性コア１３を使用する図６の場合は
逆に大電流側で同磁性コア１３の飽和或は高感度化によ
るファラデー素子２７の飽和が起きて、電流測定範囲を
広くすることができない。 前記した多導体の電流測定方法では、各導体１１に
光磁界センサ１２を設置するので光磁界センサ１２の数
が多くなって計測システムが複雑になり、測定作業がし
にくくなったり、同システムが高くなったりする。The conventional measuring method described above has the following problems. In the case of FIG. 4 in which the magnetic core with a gap is not used, the measurement accuracy on the low current side is reduced. In the case of FIG. 6 using the magnetic core 13 with a gap, conversely, saturation of the magnetic core 13 on the large current side or saturation of the Faraday element 27 due to high sensitivity occurs, and the current measurement range cannot be widened. In the multi-conductor current measuring method described above, since the optical magnetic field sensor 12 is installed in each conductor 11, the number of the optical magnetic field sensors 12 increases, the measurement system becomes complicated, and the measurement work becomes difficult. It gets expensive.
【０００８】本発明の目的は広い電流範囲を高精度で測
定でき、しかも多導体に流れる同相電流の和を１台の光
磁気センサで測定できるようにした電流測定方法を提供
することにある。An object of the present invention is to provide a current measuring method capable of measuring a wide current range with high accuracy and measuring the sum of in-phase currents flowing in multiple conductors with one magneto-optical sensor.
【０００９】[0009]
【課題を解決するための手段】本発明の光磁界センサに
よる電流測定方法は、図１に示すように同相電流が流れ
る二以上の被測定導体１の任意の被測定導体１に変流器
２を設置し、夫々の変流器２の二次側出力を個別に共通
のギャップ付き磁性コア３に印加し、同磁性コア３のギ
ャップ４中に設置した光磁界センサ５により同磁性コア
３の磁界に応じて強度変化する光信号を得、その光信号
を処理して被測定導体１に流れる電流を測定するように
したものである。As shown in FIG. 1, a current measuring method using an optical magnetic field sensor according to the present invention includes a current transformer 2 which is connected to an arbitrary measured conductor 1 of two or more measured conductors 1 through which an in-phase current flows. Is installed, and the secondary side output of each current transformer 2 is individually applied to the common magnetic core 3 with a gap, and the optical magnetic field sensor 5 installed in the gap 4 of the same magnetic core 3 causes the magnetic core 3 An optical signal whose intensity changes according to a magnetic field is obtained, the optical signal is processed, and the current flowing through the conductor 1 to be measured is measured.
【００１０】[0010]
【作用】本発明の光磁界センサによる電流測定方法で
は、図１のように被測定導体１に取り付けられた変流器
２の二次側出力Ｉ2 は被測定電流Ｉ1 に比例する。この
二次側出力Ｉ2 がギャップ付き磁性コア３に印加され、
同磁性コア３において被測定電流Ｉ1 に応じた磁界が発
生する。このとき、ギャップ付き磁性コア３のギャップ
４中に設置されている光磁界センサ５のファラデ−素子
２７（図５）に偏光された光波を入射すると、同ギャッ
プ付き磁性コア３から生じてファラデ−素子２７に加わ
る磁界に応じて前記光波の強度が変化し、光磁界センサ
５の出力ＰはＰ∝Ｉ2 ∝Ｉ1 となり、被測定電流Ｉ1 に
比例したセンサ出力Ｐが得られる。In the current measuring method using the optical magnetic field sensor of the present invention, the secondary output I 2 of the current transformer 2 attached to the conductor 1 to be measured as shown in FIG. 1 is proportional to the current I 1 to be measured. This secondary side output I 2 is applied to the magnetic core 3 with a gap,
In the magnetic core 3, a magnetic field corresponding to the measured current I 1 is generated. At this time, when the polarized light wave is incident on the Faraday element 27 (FIG. 5) of the optical magnetic field sensor 5 installed in the gap 4 of the magnetic core 3 with a gap, it is generated from the magnetic core 3 with a gap and the Faraday element is generated. The intensity of the light wave changes according to the magnetic field applied to the element 27, and the output P of the optical magnetic field sensor 5 becomes P∝I 2 ∝I 1 , and the sensor output P proportional to the measured current I 1 is obtained.
【００１１】例えば被測定電流Ｉ1 の範囲が１００Ａ〜
１００ＫＡ、変流器の変流比が５０：１とすると、変流
器２の二次側出力Ｉ2 の範囲は２Ａ＜Ｉ2 ＜２ＫＡとな
り、ギャップ付き磁性コア３を用いた光磁界センサ５に
よる測定方法により十分な精度が得られる。For example, the range of the measured current I 1 is 100A to
Assuming that the current transformer has a current transformer ratio of 100: 1 and a current transformer ratio of 50: 1, the range of the secondary output I 2 of the current transformer 2 is 2A <I 2 <2KA, and the optical magnetic field sensor 5 using the magnetic core 3 with a gap is shown. Sufficient accuracy can be obtained by the measuring method according to.
【００１２】ちなみに、被測定導体１に流れる電流Ｉ1
を変流器２を通さずにそのまま測定すると、大電流側に
おいて磁性コア３の飽和またはファラデー素子２７の飽
和により十分な精度が得られない。また、大電流で飽和
しない透磁率の小さい材料または十分大きな磁性コア３
を使用すると、前者では低電流側の精度が落ち、後者で
は重量が非常に大きくなる。また、磁性コア３を使用し
ない場合は低電流側の精度が低下する。Incidentally, the current I 1 flowing through the conductor 1 to be measured is
If it is measured without passing through the current transformer 2, sufficient accuracy cannot be obtained due to the saturation of the magnetic core 3 or the Faraday element 27 on the large current side. In addition, a material having a small magnetic permeability or a sufficiently large magnetic core 3 which is not saturated with a large current
When used, the accuracy on the low current side is reduced in the former case, and the weight is greatly increased in the latter case. Further, when the magnetic core 3 is not used, the accuracy on the low current side decreases.
【００１３】[0013]
【実施例】図１に示す実施例は被測定導体１が一本の場
合であり、この場合は、その被測定導体１に変流器２を
設け、同変流器２の二次側出力をギャップ付き磁性コア
３に印加し、同磁性コア３のギャップ４中に設置した光
磁界センサ５により同磁性コア３の磁界に応じて強度変
化する光信号を得、その光信号を図示されていないＯ／
Ｅ変換器で電気変換し、所定の処理をして被測定導体１
に流れる電流を測定するようにしてある。The embodiment shown in FIG. 1 is a case in which there is one conductor 1 to be measured. In this case, a current transformer 2 is provided on the conductor 1 to be measured, and the secondary side output of the current transformer 2 is provided. Is applied to the magnetic core 3 with a gap, an optical magnetic field sensor 5 installed in the gap 4 of the magnetic core 3 obtains an optical signal whose intensity changes according to the magnetic field of the magnetic core 3, and the optical signal is shown in the figure. Not O /
Conducting electrical conversion with the E converter, performing the specified processing, and measuring conductor 1
The current flowing through is measured.
【００１４】図２に示す実施例は被測定導体１が二本以
上の場合であり、この場合は、任意の被測定導体１に変
流器２を設け、各変流器２の二次側出力を個別に共通の
（一つの）ギャップ付き磁性コア３に印加し、同磁性コ
ア３のギャップ４中に設置した光磁界センサ５により同
磁性コア３の磁界に応じて強度変化する光信号を得、そ
の光信号を図示されていないＯ／Ｅ変換器で電気変換
し、所定の処理をして各被測定導体１に流れる電流の和
を計測するようにしてある。The embodiment shown in FIG. 2 is a case in which there are two or more conductors 1 to be measured. In this case, a current transformer 2 is provided on any conductor 1 to be measured, and a secondary side of each current transformer 2 is provided. The outputs are individually applied to a common (one) magnetic core 3 with a gap, and an optical magnetic field sensor 5 installed in the gap 4 of the magnetic core 3 outputs an optical signal whose intensity changes according to the magnetic field of the magnetic core 3. Then, the optical signal is electrically converted by an O / E converter (not shown), a predetermined process is performed, and the sum of the currents flowing through the conductors 1 to be measured is measured.
【００１５】図２に示す実施例は変流器２の二次側巻線
６をギャップ付き磁性コア３に所望回数巻き付けるよう
にしたものである。In the embodiment shown in FIG. 2, the secondary winding 6 of the current transformer 2 is wound around the magnetic core 3 with a gap a desired number of times.
【００１６】本発明で使用する光磁界センサ５には、図
４、図５の光磁界センサと同じものを使用できる。As the optical magnetic field sensor 5 used in the present invention, the same optical magnetic field sensor as shown in FIGS. 4 and 5 can be used.
【００１７】[0017]
【発明の効果】本発明の光磁界センサによる電流測定方
法は次の様な効果がある。 被測定導体１と光磁界センサ４の間に変流器２を入
れることにより、光磁界センサ４に印加される磁界を適
切な範囲に設定することができ、その結果、広い範囲の
電流値を高精度で測定することができる。 多導体の場合、各々の被測定導体１に取りつけた変
流器２の二次側出力を光磁界センサ４のギャップ付き磁
性コア３で合成することによって、多導体に流れる電流
を１台の光磁界センサ４で測定可能になる。このため、
超高電圧を伝送する超高圧送電線のように、分岐された
多導体の夫々の電流を計測するのに特に適する。 多導体の電流を測定する場合でも光磁界センサ４が
１台で済むので電流測定システムの構成が簡潔になり、
計測し易く、しかも安価な電流測定システムとなる。The current measuring method using the optical magnetic field sensor of the present invention has the following effects. By inserting the current transformer 2 between the conductor to be measured 1 and the optical magnetic field sensor 4, the magnetic field applied to the optical magnetic field sensor 4 can be set in an appropriate range, and as a result, a wide range of current values can be obtained. It can be measured with high accuracy. In the case of multiple conductors, the secondary side output of the current transformer 2 attached to each conductor to be measured 1 is combined by the magnetic core 3 with a gap of the optical magnetic field sensor 4 so that the current flowing through the multiple conductors is converted into one light source. It becomes possible to measure with the magnetic field sensor 4. For this reason,
It is particularly suitable for measuring the current of each of the branched multiconductors, such as an ultra high voltage transmission line transmitting an ultra high voltage. Even when measuring the currents of multiple conductors, only one optical magnetic field sensor 4 is required, which simplifies the configuration of the current measurement system.
The current measurement system is easy to measure and inexpensive.
【図１】本発明の光磁界センサによる電流測定方法の一
実施例を示す説明図。FIG. 1 is an explanatory diagram showing an embodiment of a current measuring method using an optical magnetic field sensor of the present invention.
【図２】本発明の光磁界センサによる電流測定方法の他
の実施例を示す説明図。FIG. 2 is an explanatory view showing another embodiment of the current measuring method by the optical magnetic field sensor of the present invention.
【図３】本発明の光磁界センサによる電流測定方法の更
に他の実施例を示す説明図。FIG. 3 is an explanatory view showing still another embodiment of the current measuring method by the optical magnetic field sensor of the present invention.
【図４】従来の光磁界センサによる電流測定方法の説明
図。FIG. 4 is an explanatory diagram of a current measuring method using a conventional optical magnetic field sensor.
【図５】ファラデー素子を使用した光磁界センサの説明
図。FIG. 5 is an explanatory diagram of an optical magnetic field sensor using a Faraday element.
【図６】従来の光磁界センサによる電流測定方法の他例
を示す説明図。FIG. 6 is an explanatory view showing another example of a current measuring method using a conventional optical magnetic field sensor.
１ 被測定導体 ２ 変流器 ３ ギャップ付き磁性コア ４ ギャップ ５ 光磁界センサ 1 conductor to be measured 2 current transformer 3 magnetic core with gap 4 gap 5 optical magnetic field sensor
───────────────────────────────────────────────────── フロントページの続き (72)発明者 西村 英一 東京都千代田区丸の内２丁目６番１号 古 河電気工業株式会社内 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Eiichi Nishimura 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.
Claims (1)
の任意の被測定導体１に変流器２を設置し、夫々の変流
器２の二次側出力を個別に共通のギャップ付き磁性コア
３に印加し、同磁性コア３のギャップ４中に設置した光
磁界センサ５により同磁性コア３の磁界に応じて強度変
化する光信号を得、その光信号を処理して被測定導体１
に流れる電流を測定するようにしたことを特徴とする光
磁界センサによる電流測定方法。1. Two or more conductors to be measured 1 in which a common mode current flows.
A current transformer 2 is installed on any of the conductors 1 to be measured, and the secondary side output of each current transformer 2 is individually applied to a common magnetic core 3 with a gap. The installed optical magnetic field sensor 5 obtains an optical signal whose intensity changes in accordance with the magnetic field of the magnetic core 3, and processes the optical signal to measure the conductor 1 under measurement.
A method of measuring a current by an optical magnetic field sensor, characterized in that a current flowing through the sensor is measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3354818A JPH05172854A (en) | 1991-12-19 | 1991-12-19 | Measurement of electric current by photomagnetic field sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3354818A JPH05172854A (en) | 1991-12-19 | 1991-12-19 | Measurement of electric current by photomagnetic field sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05172854A true JPH05172854A (en) | 1993-07-13 |
Family
ID=18440108
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3354818A Pending JPH05172854A (en) | 1991-12-19 | 1991-12-19 | Measurement of electric current by photomagnetic field sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05172854A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007112600A1 (en) * | 2006-04-04 | 2007-10-11 | Abb Research Ltd | Fiber-optic current sensor with sum detection |
-
1991
- 1991-12-19 JP JP3354818A patent/JPH05172854A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007112600A1 (en) * | 2006-04-04 | 2007-10-11 | Abb Research Ltd | Fiber-optic current sensor with sum detection |
| CN101449174A (en) * | 2006-04-04 | 2009-06-03 | Abb研究有限公司 | Optical fiber current sensor having sum detection |
| US7876448B2 (en) | 2006-04-04 | 2011-01-25 | Abb Research Ltd. | Fiber-optic current sensor with sum detection |
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