JPH01305365A - Three-phase system photocurrent sensor - Google Patents
Three-phase system photocurrent sensorInfo
- Publication number
- JPH01305365A JPH01305365A JP63137872A JP13787288A JPH01305365A JP H01305365 A JPH01305365 A JP H01305365A JP 63137872 A JP63137872 A JP 63137872A JP 13787288 A JP13787288 A JP 13787288A JP H01305365 A JPH01305365 A JP H01305365A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- phase
- faraday
- sensor
- optical signal
- 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
- 239000004020 conductor Substances 0.000 claims abstract description 23
- 230000003287 optical effect Effects 0.000 claims abstract description 18
- 239000013307 optical fiber Substances 0.000 claims abstract description 17
- 239000012212 insulator Substances 0.000 claims abstract description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 15
- 230000035699 permeability Effects 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 abstract description 5
- 239000006185 dispersion Substances 0.000 abstract 1
- 239000000696 magnetic material Substances 0.000 description 4
- 230000005856 abnormality Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
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- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は送電線の電流や電圧の異常を感知するために用
いられる三相式光電流センサに関するものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a three-phase photocurrent sensor used for sensing abnormalities in current and voltage in power transmission lines.
（従来の技術）
３相線路において各相の電流等を測定するためには、各
導体に対してそれぞれ電流を光信号に変換するセンサを
取付け、各センサに対して個々に光ファイバを介して光
信号を送り、各センサがら取出された光信号を個々に変
換器に導いたうぇ３相合成を行うのが普通であった。し
かしこのような従来のものは高価なＯ／Ｅ、Ｅ１０変換
器が３台ずつ必要であること、このため変換器の消費電
力も大きくなること、光ファイバの総延長距離が長くな
ること、また各センサの感度のばらつきを調整すること
はできないために電気信号に変換した後、各センサの出
力を調整して３相合成を行って零相電流値を出す必要が
あり、出力調整回路を各センサ個別に設ける必要があっ
た。(Prior art) In order to measure the current of each phase in a three-phase line, a sensor that converts the current into an optical signal is attached to each conductor, and each sensor is individually connected via an optical fiber. It was common practice to send an optical signal and guide the optical signals extracted from each sensor to a converter individually to perform three-phase synthesis. However, such conventional systems require three expensive O/E and three E10 converters, which increases the power consumption of the converters, increases the total length of the optical fiber, and Since it is not possible to adjust the sensitivity variations of each sensor, it is necessary to convert the output of each sensor into an electrical signal, adjust the output of each sensor, perform three-phase synthesis, and output the zero-sequence current value. It was necessary to provide separate sensors.
（発明が解決しようとする課題）
本発明は上記のような従来の問題点を解決して、経済性
に優れ、光ファイバの総延長距離を短縮化でき、また零
相電流値に誤差が生ずるおそれのないようにした三相式
光電流センサを目的として完成されたものである。(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, is economical, reduces the total length of optical fiber, and eliminates errors in zero-sequence current values. It was completed with the aim of creating a three-phase photocurrent sensor that would be free from such risks.
（課題を解決するための手段）
本発明は光ファイバを内蔵させた碍子本体の下端に導体
を流れる電流により発生する磁界を光信号で検出するフ
ァラディ素子と、このファラディ素子を通過する磁界の
強さを調整する磁界調整機構とを設けたセンサ付き碍子
を３相の導体にそれぞれ取付けるとともに、これらのフ
ァラディ素子を光ファイバにより直列に結合して３相分
の電流を光信号により合成した零相電流分として取出す
ことを特徴とするものである。(Means for Solving the Problems) The present invention provides a Faraday element that detects, as an optical signal, a magnetic field generated by a current flowing through a conductor at the lower end of an insulator body in which an optical fiber is built-in, and the strength of the magnetic field passing through the Faraday element. A sensor-equipped insulator equipped with a magnetic field adjustment mechanism for adjusting the magnetic field is attached to each of the three-phase conductors, and these Faraday elements are connected in series through optical fibers to create a zero-phase signal that combines the three-phase currents using an optical signal. It is characterized by being extracted as a current component.
（実施例） 次に本発明を図示の実施例により更に詳細に説明する。(Example) Next, the present invention will be explained in more detail with reference to illustrated embodiments.
第１図はシステム全体の構成図であり、（１）、（１）
、（１）は３相線路における３本の導体、（２）は各導
体（りにそれぞれ取付けられたセンサ付き碍子である、
第２図に拡大して示したように、センサ付き碍子（２）
は光ファイバ（３）を内蔵させた碍子本体（４）の下端
に導体ｆｌ）をクランプするための導体クランプ（５）
を設けるとともに、碍子側の導体クランプ（５）の内部
に導体（１）を流れる電流により発生する磁界を感知し
て光電流で検出するファラディ素子（６）を取付けたも
のである。第２図に示す第１の実施例では導体クランプ
（５）としてアルミニウムのような非磁性体が使われて
おり、そのねじ孔（７）の内部に導体ｆｌ＋の半径線方
向に進退自在に螺挿された素子収納部（８）内にファラ
ディ素子（６）が収納されている。第３図に示すように
、磁界の強さは導体外表面がらの距離が変化すると大き
く変化するので、素子収納部（８）をねし孔（７）の内
部で進退動させるとファラディ素子（６）を通過する磁
界の強さが変化し、ファラディ素子（６）の感度が変わ
ることとなる。従って第１の実施例では、これらのねし
孔（７）と素子収納部（８）とによって磁界調整機構（
９）が構成されていることになる。なお、素子収納部（
８）の位置に関係なくファラディ素子（６）は導体＋１
）により発生する磁界の方向と同一方向になるようにし
であることは言うまでもない。Figure 1 is a diagram of the overall system configuration, (1), (1)
, (1) is the three conductors in a three-phase line, (2) is an insulator with a sensor attached to each conductor,
As shown enlarged in Figure 2, insulator with sensor (2)
is a conductor clamp (5) for clamping the conductor fl) to the lower end of the insulator body (4) containing the optical fiber (3).
In addition, a Faraday element (6) that senses the magnetic field generated by the current flowing through the conductor (1) and detects it using photocurrent is attached inside the conductor clamp (5) on the insulator side. In the first embodiment shown in FIG. 2, a non-magnetic material such as aluminum is used as the conductor clamp (5), and a screw is inserted into the screw hole (7) so that it can move forward and backward in the radial direction of the conductor fl+. A Faraday element (6) is housed in the inserted element housing part (8). As shown in Figure 3, the strength of the magnetic field changes greatly as the distance from the outer surface of the conductor changes, so when the element housing (8) is moved back and forth inside the screw hole (7), the Faraday element ( The strength of the magnetic field passing through the Faraday element (6) changes, and the sensitivity of the Faraday element (6) changes. Therefore, in the first embodiment, the magnetic field adjustment mechanism (
9) is configured. In addition, the element storage part (
Faraday element (6) is conductor +1 regardless of the position of
), it goes without saying that the direction is the same as the direction of the magnetic field generated by the magnetic field.
光ファイバ（３）は碍子本体（４）の内部を貫通してこ
のファラディ素子（６）に達し、磁界の強さに応じて光
信号を取出すものであるが、本発明では第１図に示され
るように一本の光ファイバ（３）が３相のそれぞれに対
応する３つのファラディ素子（６）を直列に結合してお
り、その両端は変換器Ｑｌに引込まれている。そして光
ファイバ（３）の一端にはドライバ回路αυにより発光
される発光素子（ロ）が設けられており、他端には受光
素子Ｉ、増幅回路０４１等が設けられている。従って発
光素子側により発生された光信号は各相に対応する３つ
のファラディ素子（６）の内部を順次通過する際に各相
の導体＋１）を流れる電流による磁界によって順次偏波
面を回転され、それらが合成された信号として受光素子
αｌに入り電気信号に変換される。The optical fiber (3) passes through the inside of the insulator body (4) to reach the Faraday element (6) and extracts an optical signal depending on the strength of the magnetic field. One optical fiber (3) connects three Faraday elements (6) corresponding to each of the three phases in series, and both ends thereof are led into the converter Ql. One end of the optical fiber (3) is provided with a light emitting element (b) that emits light by the driver circuit αυ, and the other end is provided with a light receiving element I, an amplifier circuit 041, etc. Therefore, when the optical signal generated by the light emitting element side sequentially passes through the three Faraday elements (6) corresponding to each phase, the plane of polarization is sequentially rotated by the magnetic field caused by the current flowing through the conductor +1) of each phase. They enter the light receiving element αl as a combined signal and are converted into an electrical signal.
第４図は磁界調整機構（９）の他の例を示すもので、碍
子本体（４）の下端に鉄心α９を設け、その鉄心Ｑ９に
設けられたギャップの内部に円筒形の素子収納部（８）
を回転自在に設けたものである。この実施例では素子収
納部（８）の外周面にはねじが切ってあり、鉄心のギャ
ップを横断する磁界の方向に対して素子収納部（８）と
ともにファラディ素子（６）が回転できるようになりで
いる。一般に素子を通過する磁界の強さＨｓは、ギャッ
プ部分の磁界をＨ，、素子が磁界の方向に対してなす角
度をθとしたとき、Ｈｓ”Ｈｇ ’ ＣＯｓθで表現さ
れるので、角度θを変えることによって磁界調整ができ
ることとなる。FIG. 4 shows another example of the magnetic field adjustment mechanism (9), in which an iron core α9 is provided at the lower end of the insulator body (4), and a cylindrical element storage portion ( 8)
is rotatably provided. In this embodiment, the outer circumferential surface of the element housing (8) is threaded so that the Faraday element (6) can rotate together with the element housing (8) in the direction of the magnetic field that crosses the gap in the core. Be as you are. In general, the strength Hs of the magnetic field passing through the element is expressed as Hs''Hg' COsθ, where H is the magnetic field in the gap and θ is the angle the element makes with respect to the direction of the magnetic field, so the angle θ is By changing this, the magnetic field can be adjusted.
第５図は磁界調整機構（９）の他の例を示すもので、鉄
心α９にテーパ状のギャップを設け、その内部に素子収
納部（８）とともにファラディ素子（６）を進退動自在
に支持させたものである。更に第６図は磁界稠整機構（
９）の他の例を示すもので、先細状のギャップの内部に
ファラディ素子（６）を直接的に進退動自在に支持させ
たものである。このようにギャップの幅を変えた場合の
磁界の変化は次式により表現される。Fig. 5 shows another example of the magnetic field adjustment mechanism (9), in which a tapered gap is provided in the iron core α9, and a Faraday element (6) is supported in the gap along with the element storage part (8) so that it can move forward and backward. This is what I did. Furthermore, Figure 6 shows the magnetic field adjustment mechanism (
This shows another example of 9), in which the Faraday element (6) is directly supported inside the tapered gap so as to be freely movable forward and backward. The change in the magnetic field when the gap width is changed in this way is expressed by the following equation.
Ｈｇ＝４πｘ ＩＱ−” ｘμｘｒ／ｌ、（１＋ １７
Ｘμ／１．）但しＨｇはギャップ部分の磁界、μは鉄心
のｉ３ｍ率、■は導体を流れる電流、！１は鉄心の周長
、２つはギャップの幅である。従ってファラディ素子（
６）を進退動させてギャップの幅の異なる部分へ移動さ
せれば、ファラディ素子（６）を通過する磁界の調整が
できることとなる。Hg=4πx IQ-” xμxr/l, (1+ 17
Xμ/1. ) However, Hg is the magnetic field in the gap, μ is the i3m ratio of the iron core, ■ is the current flowing through the conductor, ! 1 is the circumference of the iron core, and 2 is the width of the gap. Therefore, Faraday element (
The magnetic field passing through the Faraday element (6) can be adjusted by moving the faraday element (6) forward and backward to areas with different widths of the gap.
磁界調整機構（９）のその他の実施例を第７図及び第８
図に示す、鉄心ａつのギャップ間にセンサ固定部と共に
ファラディ素子（６）を固定し、鉄心αり上の他の部分
にもう１つのギャップを設け、磁性体αｅを抜きさしで
きる構造を付加する。抜きさしできる機構として図示の
ようなくし形構造が考えられる。この場合には鉄心（１
５）と磁性体ａ［９がくし形に組み合わせられるため取
付ガタがないうえ、組み合わせられている部分の磁束の
もれもおさえることができ、設計通りの磁界調整が可能
となる。Other embodiments of the magnetic field adjustment mechanism (9) are shown in FIGS. 7 and 8.
As shown in the figure, the Faraday element (6) is fixed together with the sensor fixing part between the gaps of the iron core a, and another gap is provided in the other part above the iron core α, and a structure is added that allows the magnetic body αe to be inserted and removed. do. A comb-shaped structure as shown in the figure can be considered as a mechanism that can be inserted and removed. In this case, the iron core (1
5) and the magnetic material a [9 are combined in a comb shape, there is no mounting play, and leakage of magnetic flux at the combined parts can be suppressed, making it possible to adjust the magnetic field as designed.
また磁性体Ｑｌとして、鉄心０９と同一の透磁率の材料
であれば、抜き取りしるによって磁界調整ができる、磁
性体αＱとして所要のセンサ部の磁界に合わせて鉄心０
９と異なる透磁率の材料を選択する場合には、抜き取り
しるがなくてもよく、鉄心全体の構成が簡素化できる。In addition, if the magnetic material Ql is made of a material with the same magnetic permeability as the iron core 09, the magnetic field can be adjusted by removing it.As the magnetic material αQ, the iron core 0
If a material with a magnetic permeability different from 9 is selected, there is no need to take out the cutout, and the overall configuration of the core can be simplified.
以上、このような磁界調整機構（９）を用いた場合には
、センサを固定できるため、調整時にセンサを損傷する
ことがない点で有利である。As described above, when such a magnetic field adjustment mechanism (9) is used, since the sensor can be fixed, it is advantageous in that the sensor will not be damaged during adjustment.
（作用） −
このように構成されたものは、第１図に示されるように
変換器α〔の発光素子側から光ファイバ（３）に光信号
を送り、この光信号を各相に対応するファラディ素子（
６）を順次通過させることによって３相分の電流による
光信号の変化を合成したものとして受光素子α簿に取出
すものである。そして閃絡や地絡がなく各相の電流が正
常であれば、３相の電流を合成したものは零相電流とな
ってその値はゼロとなり、従って３相分の電流による光
信号を合成したものも零相電流に対応する光信号となっ
て出力はゼロとなるが、もし３相間のバランスが崩れた
場合には零相電流に対応した光信号の出力が生ずる。従
って本発明によれば各相ごとに変換器を設けな（でも相
間閃絡、地絡等によって生ずる送電線の電流や電圧の異
常を検出することができる。また前述したとおり、磁界
を光信号に変換するファラディ素子（６）は個々の素子
の感度を微妙に調整することはできず、従って各相の電
流に異常のない場合にも零相電流値に誤差が生ずること
を避けられなかったのであるが、本発明においては各相
のセンサ付き碍子（２）にファラディ素子（６）を通過
する磁界の強さを調整できる磁界調整機構（９）を設け
であるので、ファラディ素子（６）自体の感度にばらつ
きがあっても零相電流値の誤差をなくすことができる。(Function) - As shown in Fig. 1, the device configured in this way sends an optical signal from the light emitting element side of the converter α to the optical fiber (3), and sends this optical signal to each phase. Faraday element (
6), the changes in the optical signal caused by the three-phase currents are output as a composite signal to the light receiving element α. If there is no flash fault or ground fault and the current in each phase is normal, the combination of the three phase currents becomes a zero-sequence current and its value is zero. Therefore, the optical signal from the three phase currents is combined. However, if the balance between the three phases collapses, an optical signal corresponding to the zero-sequence current will be output. Therefore, according to the present invention, it is possible to detect abnormalities in the current and voltage of power transmission lines caused by phase-to-phase flash faults, ground faults, etc., without providing a converter for each phase. It is not possible to finely adjust the sensitivity of each individual element of the Faraday element (6) that converts it into , and therefore it is unavoidable that errors occur in the zero-sequence current value even when there is no abnormality in the current of each phase. However, in the present invention, since the sensor-equipped insulator (2) of each phase is provided with a magnetic field adjustment mechanism (9) that can adjust the strength of the magnetic field passing through the Faraday element (6), the Faraday element (6) Even if there are variations in the sensitivity of the sensor itself, errors in the zero-sequence current value can be eliminated.
従って本発明によれば、零相電流値のわずかな変動をも
確実に検出することが可能となる。Therefore, according to the present invention, it is possible to reliably detect even slight fluctuations in the zero-sequence current value.
（発明の効果）
本発明は以上に説明したとおり、各相ごとに高価な変換
器を設ける必要がないので経済性に優れ、また変換器の
消費電力を小さくすることができる。また光ファイバの
総延長距離を短縮することができるとともに、３相合成
を行って得られた零相電流値に誤差が生ずることがなく
、高い検出精度を得ることができる。よって本発明は従
来の問題点を一掃した三相式光電流センサとして、産業
の発展に寄与するところは極めて大である。(Effects of the Invention) As described above, the present invention is economical because it is not necessary to provide an expensive converter for each phase, and the power consumption of the converter can be reduced. Further, the total length of the optical fiber can be shortened, and no error occurs in the zero-sequence current value obtained by performing three-phase synthesis, making it possible to obtain high detection accuracy. Therefore, the present invention greatly contributes to the development of industry as a three-phase photocurrent sensor that eliminates the problems of the conventional sensor.
第１図は本発明のシステム全体の構成図、第２図は本発
明の第１の実施例の要部を示す断面図、第３図は導体中
心からの距離と磁束との関係を示すグラフ、第４図、第
５図、第６図は第２、第３、第４の実施例の要部を示す
斜視図、第７図は第５の実施例の鉄心部分を示す正面図
、第８図はその要部の斜視図である。
（１）：導体、（２）：センサ付き碍子、（３）：光フ
ァイバ、（４）：碍子本体、（６）：ファラディ素子、
（８）：素子収納部、（９）：磁界調整機構、（２）：
鉄心。
＼
ゝ５
第３図
澁東（Ｏａ）
導イ本中邸〃〜らの託萬健（ｚｍ）
第４図
第６図Fig. 1 is a configuration diagram of the entire system of the present invention, Fig. 2 is a sectional view showing the main parts of the first embodiment of the invention, and Fig. 3 is a graph showing the relationship between the distance from the center of the conductor and magnetic flux. , FIG. 4, FIG. 5, and FIG. 6 are perspective views showing the main parts of the second, third, and fourth embodiments. FIG. 7 is a front view showing the iron core portion of the fifth embodiment. FIG. 8 is a perspective view of the main part. (1): Conductor, (2): Insulator with sensor, (3): Optical fiber, (4): Insulator body, (6): Faraday element,
(8): Element housing, (9): Magnetic field adjustment mechanism, (2):
Iron core. ＼ ゝ5 Figure 3 Shibeto (Oa) Doi Honchu Residence ~ et al.'s Trust Bank Ken (zm) Figure 4 Figure 6
Claims (1)
端に導体（１）を流れる電流により発生する磁界を光信
号で検出するファラディ素子（６）と、このファラディ
素子（６）を通過する磁界の強さを調整する磁界調整機
構（９）とを設けたセンサ付き碍子（２）を３相の導体
（１）、（１）、（１）にそれぞれ取付けるとともに、
これらのファラディ素子（６）を光ファイバ（３）によ
り直列に結合して３相分の電流を光信号により合成した
零相電流分として取出すことを特徴とする三相式光電流
センサ。 ２、磁界調整機構（９）が、鉄心（１５）のギャップの
内部で磁界の方向に対してファラディ素子（６）を回転
できる円筒形の素子収納部（８）を備えたものである請
求項１に記載の三相式光電流センサ。 ３、磁界調整機構（９）が、鉄心（１５）に設けられた
テーパ状のギャップの内部でファラディ素子（６）を進
退動させる形式のものである請求項１に記載の三相式光
電流センサ。 ４、磁界調整機構（９）が鉄心（１５）のギャップ部分
に鉄心（１５）と同じまたは異なった透磁率を持つ磁性
体（１６）を出し入れする形式のものである請求項１に
記載の三相式光電流センサ。[Claims] 1. A Faraday element (6) that detects a magnetic field generated by a current flowing through a conductor (1) using an optical signal at the lower end of an insulator body (4) incorporating an optical fiber (3); A sensor-equipped insulator (2) equipped with a magnetic field adjustment mechanism (9) that adjusts the strength of the magnetic field passing through the Faraday element (6) is attached to the three-phase conductors (1), (1), and (1), respectively. With,
A three-phase photocurrent sensor characterized in that these Faraday elements (6) are connected in series through an optical fiber (3) and three-phase currents are extracted as a zero-phase current component synthesized by an optical signal. 2. The magnetic field adjustment mechanism (9) is provided with a cylindrical element housing part (8) that can rotate the Faraday element (6) in the direction of the magnetic field inside the gap of the iron core (15). 1. The three-phase photocurrent sensor according to 1. 3. The three-phase photocurrent according to claim 1, wherein the magnetic field adjustment mechanism (9) is of a type that moves the Faraday element (6) forward and backward within a tapered gap provided in the iron core (15). sensor. 4. The magnetic field adjustment mechanism (9) according to claim 1, wherein the magnetic field adjustment mechanism (9) is of a type that inserts and removes a magnetic body (16) having the same or different magnetic permeability as the iron core (15) into and out of the gap portion of the iron core (15). Phase type photocurrent sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63137872A JPH01305365A (en) | 1988-06-03 | 1988-06-03 | Three-phase system photocurrent sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63137872A JPH01305365A (en) | 1988-06-03 | 1988-06-03 | Three-phase system photocurrent sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01305365A true JPH01305365A (en) | 1989-12-08 |
Family
ID=15208679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63137872A Pending JPH01305365A (en) | 1988-06-03 | 1988-06-03 | Three-phase system photocurrent sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01305365A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2128631A1 (en) * | 2008-05-30 | 2009-12-02 | PowerSense A/S | Faraday optical current sensor arrangement |
| US8692539B2 (en) | 2006-11-30 | 2014-04-08 | Powersense A/S | Faraday effect current sensor |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5615515B2 (en) * | 1975-07-24 | 1981-04-10 | ||
| JPS62110162A (en) * | 1985-11-08 | 1987-05-21 | Sumitomo Electric Ind Ltd | Apparatus for detecting zero phase current |
-
1988
- 1988-06-03 JP JP63137872A patent/JPH01305365A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5615515B2 (en) * | 1975-07-24 | 1981-04-10 | ||
| JPS62110162A (en) * | 1985-11-08 | 1987-05-21 | Sumitomo Electric Ind Ltd | Apparatus for detecting zero phase current |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8692539B2 (en) | 2006-11-30 | 2014-04-08 | Powersense A/S | Faraday effect current sensor |
| EP2128631A1 (en) * | 2008-05-30 | 2009-12-02 | PowerSense A/S | Faraday optical current sensor arrangement |
| WO2009143851A1 (en) * | 2008-05-30 | 2009-12-03 | Powersense A/S | Faraday optical current sensor arrangement |
| US8525512B2 (en) | 2008-05-30 | 2013-09-03 | Powersense A/S | Faraday optical current sensor arrangement |
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