JPH0614112B2 - Current measuring device - Google Patents
Current measuring deviceInfo
- Publication number
- JPH0614112B2 JPH0614112B2 JP61232179A JP23217986A JPH0614112B2 JP H0614112 B2 JPH0614112 B2 JP H0614112B2 JP 61232179 A JP61232179 A JP 61232179A JP 23217986 A JP23217986 A JP 23217986A JP H0614112 B2 JPH0614112 B2 JP H0614112B2
- Authority
- JP
- Japan
- Prior art keywords
- current
- integrator
- measuring device
- coils
- electric wire
- 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.)
- Expired - Lifetime
Links
Landscapes
- Measuring Magnetic Variables (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
- Measurement Of Current Or Voltage (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、電線に流れている電流を電線を切断すること
なく、活線のまま測定する電流測定装置に関し、更に詳
しくは、電線路への装着が容易で、且つ、変流器部に可
動部分を有しないＵ字形解放鉄心を用いた電流測定装置
に関する。Description: TECHNICAL FIELD The present invention relates to a current measuring device for measuring a current flowing in an electric wire as it is without cutting the electric wire, and more specifically, to an electric line. The present invention relates to a current measuring device using a U-shaped open core, which is easy to mount and has no moving part in the current transformer part.
（従来の技術） Ｕ字形解放鉄心を用いた変流器によって、電線を流れる
電流をピックアップし、電線を切断することなく電流測
定を行う電線路用電流測定装置は、従来より公知であ
る。(Prior Art) A current measuring device for an electric line has been conventionally known which picks up a current flowing through an electric wire by a current transformer using a U-shaped open iron core and measures the current without cutting the electric wire.
このような構成の電流測定装置は、電線路への装着が容
易であり、又、電線路に対して非接触で簡便に電流測定
が行えることから、高圧回路において、大電流の測定を
行う場合に特に有効で、これまで長い間利用されてき
た。The current measuring device having such a configuration can be easily mounted on the electric line and can easily measure the current without contacting the electric line. Therefore, when measuring a large current in a high voltage circuit. It is especially effective for and has been used for many years.
（発明が解決しようとする問題点） しかしながら、Ｕ字形解放鉄心を用いた変流器は、鉄心
のエアギャップ（air gap）が極端に大きいために、等
価的な励磁電流が大きい。このため５０Ｈｚと６０Ｈｚ
の商用周波数を指定しないと周波数誤差が大きくなるう
えに、第３高調波等にも感度が大幅に変化するため、こ
れが波形誤差となる等の問題点があった。(Problems to be Solved by the Invention) However, in the current transformer using the U-shaped open core, the equivalent exciting current is large because the air gap of the core is extremely large. Therefore, 50Hz and 60Hz
If the commercial frequency is not specified, the frequency error becomes large, and the sensitivity also greatly changes to the third harmonic and the like, which causes a problem such as a waveform error.
本発明はこのような問題点に鑑みてなされたもので、そ
の目的は、周波数特性を改善すると共に、波形歪を改善
し、測定精度の高い電流側測定装置を実現することにあ
る。The present invention has been made in view of such problems, and an object thereof is to improve a frequency characteristic, improve waveform distortion, and realize a current-side measuring device with high measurement accuracy.
（問題点を解決するための手段） 前記した問題点を解決する本発明は、互いに対向する両
脚にそれぞれコイルが設けられたＵ字形解放鉄心を用い
た変流器部と、前記両脚に挟まれた位置にある電線から
発生する磁束によって各コイルに誘起する起電力が加算
されて印加される積分器とからなり、積分器の出力信号
から電線を流れる電流を知るようにしたことを特徴とす
るものである。(Means for Solving Problems) According to the present invention for solving the above problems, a current transformer part using U-shaped open cores in which coils are provided on both legs facing each other, and a current transformer part is sandwiched between the legs. It consists of an integrator that is applied by adding the electromotive force induced in each coil by the magnetic flux generated from the electric wire at a certain position, and the current flowing through the electric wire is known from the output signal of the integrator. It is a thing.
（実施例） 以下、図面を用いて本発明の実施例を詳細に説明する。(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
第１図は本発明装置の原理的な構成ブロック図であり、
第２図は斜視図である。これらの図において、１はＵ字
形解放鉄心（空芯を含む）を用いた変流器部分で、互い
に対向する両脚にコイル１１，１２が設けられ、両脚中
央のマークｍ１，ｍ２を結ぶ線上位置に電線２が通るよ
うに構成されている。この変流器部分１は、第２図に示
すように可動するクリップ機構の無い構造となってい
る。FIG. 1 is a block diagram showing the basic configuration of the device of the present invention.
FIG. 2 is a perspective view. In these figures, 1 is a current transformer part using a U-shaped open core (including an air core), coils 11 and 12 are provided on both legs facing each other, and marks m 1 and m 2 at the center of both legs are connected. The electric wire 2 is configured to pass through the position on the line. This current transformer portion 1 has a structure without a movable clip mechanism as shown in FIG.
３はコイル１１，１２からの信号ｅ０を積分し、電線２
を流れる電流ｉに比例した信号を出力する積分器であ
る。ここで、互いに対向して配置される２つのコイル１
１，１２は、２つのコイル１１，１２によって挟まれた
内側に位置する電線２から発生する磁束Φによる起電力
ｅ１，ｅ２が互いに和の形（ｅ１＋ｅ２）となり、２つ
のコイル１１，１２の外側に位置する電線２１から発生
する磁束による起電力ｅ１１，ｅ２１に対しては差の形
（ｅ１１−ｅ２１）となるように直列に接続され、前述
の和信号（ｅ１＋ｅ２）が積分器３に印加されるように
なっている。3 integrates the signal e 0 from the coils 11 and 12, and
Is an integrator that outputs a signal proportional to the current i flowing through. Here, two coils 1 arranged to face each other
1 and 12 have a sum form (e 1 + e 2 ) of electromotive forces e 1 and e 2 due to the magnetic flux Φ generated from the electric wire 2 located inside sandwiched by the two coils 11 and 12, and thus the two coils electromotive force e 11 by magnetic flux generated from the wire 21 to be located outside the 11 and 12, for e 21 are connected in series so as to form the difference (e 11 -e 21), the aforementioned sum signal ( e 1 + e 2 ) is applied to the integrator 3.
４は測定電流値を指示する指示計で、ここではディジタ
ル値で表示するようになっている。尚、この場合、積分
器３の出力はＡ／Ｄ変換器によってディジタル信号に変
換されるものとする。Reference numeral 4 is an indicator for indicating the measured current value, which is displayed here as a digital value. In this case, the output of the integrator 3 is converted into a digital signal by the A / D converter.
このように構成した装置の動作を説明すれば以下の通り
である。測定に先だって、被測定電流ｉが流れている電
線２を、第２図に示すように変流器部分１の両脚中央に
位置させる。この場合、電線２を流れる電流ｉによって
生じた磁束φは、第１図破線に示すように２つのコイル
１１，１２に交差し、各コイル１１，１２には（１）
式，（２）式で表わされるような電圧ｅ１，ｅ２が誘起
する。The operation of the apparatus thus configured will be described below. Prior to the measurement, the electric wire 2 in which the measured current i is flowing is positioned at the center of both legs of the current transformer portion 1 as shown in FIG. In this case, the magnetic flux φ generated by the current i flowing through the electric wire 2 intersects the two coils 11 and 12 as shown by the broken line in FIG. 1, and each coil 11 and 12 has (1)
The voltages e 1 and e 2 as expressed by the equation (2) are induced.
ｅ１＝Ｋ１・（ｄφ／dt）・ｎ１ …（１） ｅ２＝Ｋ２・（ｄφ／dt）・ｎ２ …（２） 但し、ｋ１，ｋ２は定数、ｎ１，ｎ２はコイル１１，１
２の巻数 （１），（２）式において、定数ｋ１，ｋ２は各コイル
１１，１２の相対関係を等しくすることによりｋ１＝ｋ
２＝ｋとなり、又、各コイル１１，１２の巻数ｎ１，ｎ
２の和ｎ１＋ｎ２をＮとすれば、積分器３への入力信号
eiは（３）式の通りとなる。e 1 = K 1 · (dφ / dt) · n 1 (1) e 2 = K 2 · (dφ / dt) · n 2 (2) where k 1 and k 2 are constants and n 1 and n 2 is coil 11, 1
Number of turns of 2 In equations (1) and (2), the constants k 1 and k 2 are k 1 = k by making the relative relationships of the coils 11 and 12 equal.
2 = k, and the number of turns n 1 , n of each coil 11, 12
If the sum n 1 + n 2 of 2 is N, the input signal to the integrator 3
ei is given by equation (3).
ei＝ｅ１＋ｅ２ ＝Ｋ・（ｄφ／dt）・（ｎ１＋ｎ２） ＝Ｋ．（ｄφ／dt）・Ｎ …（３） 積分器３はこの入力信号eiを積分し、（４）式に表わさ
れるような出力信号ｅ０を得る。ei = e 1 + e 2 = K · (dφ / dt) · (n 1 + n 2 ) = K. (Dφ / dt) · N (3) The integrator 3 integrates the input signal ei to obtain the output signal e 0 as expressed by the equation (4).
ｅ０＝∫ei dt ＝∫Ｋ．（ｄφ／dt）・Ｎdt ＝Ｋ・φ・Ｎ …（４） （４）式において、磁束φは電流ｉに比例しているの
で、結局積分器３の出力信号ｅ０は、（５）式の通りと
なり、これより被測定電流ｉを知ることができる。又、
その信号波形は被測定電流ｉと同波形となり、波形歪を
小さくすることができる。e 0 = ∫ei dt = ∫K. (Dφ / dt) · Ndt = K · φ · N (4) In the equation (4), the magnetic flux φ is proportional to the current i, so that the output signal e 0 of the integrator 3 is the equation (5). The measured current i can be known from this. or,
The signal waveform has the same waveform as the measured current i, and the waveform distortion can be reduced.
ｅ０＝Ｋ０・ｉ …（５） 但し、Ｋ０は定数 第３図は、本発明装置の具体的な回路例を示す接続図で
ある。この回路例において、コイル１１，１２はそれぞ
れ空芯に巻回したものであり、積分器３は、コンデンサ
Ｃ１，抵抗Ｒ１，Ｒ２及び増幅器ＯＰ１で構成してあ
る。又、積分器３の出力は実効値変換回路５を通すこと
によって、実効値を得るようにし、Ａ／Ｄ変換器６を介
して指示計４で、電流ｉの実効値を表示している。e 0 = K 0 · i (5) where K 0 is a constant FIG. 3 is a connection diagram showing a specific circuit example of the device of the present invention. In this circuit example, the coils 11 and 12 are each wound around an air core, and the integrator 3 is composed of a capacitor C 1 , resistors R 1 and R 2, and an amplifier OP 1 . The output of the integrator 3 is passed through the effective value conversion circuit 5 to obtain an effective value, and the indicator 4 is displayed by the indicator 4 via the A / D converter 6.
第４図は、第３図において各回路定数を以下のように選
定した場合の周波数特性である。FIG. 4 shows frequency characteristics when the respective circuit constants in FIG. 3 are selected as follows.
Ｃ１＝１μＦ Ｒ１＝１ＫΩ、Ｒ２＝１００ＫΩ ｅ０＝１０００ｍＶ／１０Ａ コイル１１，１２の巻数ｎ１，ｎ２ ｎ１＝ｎ２＝１５０００ｔ コイル１１と１２の距離ｌ＝２０mm この実験結果から明らかなように、本発明装置によれ
ば、４０Ｈｚ〜４００Ｈｚの周波数範囲において、測定
誤差をフルスケールに対して±０．５％以内とすること
ができ、又、５０Ｈｚと６０Ｈｚの差は０．１％とする
ことができ、良好な結果が得られている。C 1 = 1 μF R 1 = 1 KΩ, R 2 = 100 KΩ e 0 = 1000 mV / 10A Number of turns n 1 , n 2 n 1 = n 2 = 15000t of the coils 11 and 12 Distance l = 20 mm between the coils 11 and 12 As is apparent, according to the device of the present invention, the measurement error can be within ± 0.5% with respect to the full scale in the frequency range of 40 Hz to 400 Hz, and the difference between 50 Hz and 60 Hz is 0. It can be 1%, and a good result is obtained.
尚、上記の実施例では、各コイル１１，１２からの和信
号ｅ１＋ｅ２を直接積分器に印加するようにしたが、和
信号のレベルが小さいような場合には、演算増幅器で増
幅後、積分器に印加するようにしてもよい。In the above embodiment, the sum signal e 1 + e 2 from the coils 11 and 12 is directly applied to the integrator. However, when the sum signal level is low, it is amplified by the operational amplifier. , May be applied to the integrator.
（発明の効果） 以上詳細に説明したように、本発明によれば簡単な回路
構成で、周波数特性及び波形歪を改善でき、測定制度の
高い電流測定装置が実現できる。(Effects of the Invention) As described in detail above, according to the present invention, it is possible to realize a current measuring device having a simple circuit configuration, which can improve frequency characteristics and waveform distortion, and which has a high measurement accuracy.
第１図は本発明装置の原理的な構成ブロック図、第２図
は斜視図、第３図は具体的な回路例を示す接続図、第４
図は周波数特性を示す線図である。 １……変流器部、２……電線 ３……積分器、 ４……指示計 ５……実効値変換回路 ６……Ａ／Ｄ変換器 １１，１２…コイルFIG. 1 is a block diagram showing the basic configuration of the device of the present invention, FIG. 2 is a perspective view, FIG. 3 is a connection diagram showing a concrete circuit example, and FIG.
The figure is a diagram showing frequency characteristics. 1 ... Current transformer part, 2 ... Electric wire 3 ... Integrator, 4 ... Indicator 5 ... Effective value conversion circuit 6 ... A / D converter 11, 12 ... Coil
Claims (1)
けられたＵ字形開放鉄心を用いた変流器部と、前記両脚
に挟まれた位置にある電線から発生する磁束によって各
コイルに誘起する起電力が加算されて印加されるコンデ
ンサと非反転端子の入力側には抵抗が無く且つ該コンデ
ンサが接続される演算増幅器とよりなる積分器で構成さ
れ、この積分器の出力信号から電線を流れる電流を知る
ようにした電流測定装置。1. A current transformer section using a U-shaped open iron core, in which coils are provided on both legs facing each other, and a magnetic flux generated from an electric wire located between the legs is induced in each coil. A current flowing through the wire from the output signal of this integrator, which is composed of a capacitor to which power is added and applied and an operational amplifier to which the input side of the non-inverting terminal has no resistance and to which the capacitor is connected. Current measuring device to know.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61232179A JPH0614112B2 (en) | 1986-09-30 | 1986-09-30 | Current measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61232179A JPH0614112B2 (en) | 1986-09-30 | 1986-09-30 | Current measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6385462A JPS6385462A (en) | 1988-04-15 |
| JPH0614112B2 true JPH0614112B2 (en) | 1994-02-23 |
Family
ID=16935246
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61232179A Expired - Lifetime JPH0614112B2 (en) | 1986-09-30 | 1986-09-30 | Current measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0614112B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4004870B2 (en) * | 2002-06-25 | 2007-11-07 | 日置電機株式会社 | Current sensor |
| WO2013063773A1 (en) * | 2011-11-02 | 2013-05-10 | Honeywell International Inc. | Devices and methods for sensing current |
| CN102998522B (en) * | 2012-12-17 | 2016-09-14 | 韦兆碧 | A kind of current measuring device and method |
| WO2016125028A2 (en) * | 2015-02-03 | 2016-08-11 | Abb Technology Ltd. | System for monitoring electrical power transmission line |
| JP6166319B2 (en) * | 2015-09-17 | 2017-07-19 | 株式会社中央製作所 | Non-contact type DC current sensor and DC current measuring system using the non-contact type DC current sensor |
| US10352967B2 (en) * | 2016-11-11 | 2019-07-16 | Fluke Corporation | Non-contact electrical parameter measurement systems |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5793264A (en) * | 1980-12-01 | 1982-06-10 | Toshiba Corp | Detector for high-frequency current |
-
1986
- 1986-09-30 JP JP61232179A patent/JPH0614112B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6385462A (en) | 1988-04-15 |
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