JPH0440372A - Detection of current - Google Patents

Abstract

PURPOSE:To accurately detect a current without being affected by an external magnetic field and ambient temperature by detecting the current from the difference in magnetic fluxes of two iron cores having rectangular hysteresis characteristics and consisting of the material with small coercive force. CONSTITUTION:When a DC current I flows in a conductor 18, a DC magnetic field +Hi is applied to the iron core 15a the magnetic field of iron core 15a becomes the sum with a magnetic field Hi caused by an AC exciting current, then the range of magnetic flux change becomes small, and also a magnetic flux density and a waveform of induced voltage in a detection coil 17a become small. When the current I of conductor 18 is furthermore increased, the range of flux change is rapidly decreased and also the induced voltage in the coil 17a is rapidly decrease. When the induced voltages in detection coils 17a, 17b are amplified 21a, 21b and passed through rectifiers 22a, 22b, smoothing devices 23a, 23b and subtracting device 24, the DC voltage proportional to the difference between the induced voltages is formed. The relation between the current to be detected and the output voltage of subtracting device 24 is such as shown in the figure, in which the output voltage is sharply increased at a point I0. By utilizing this point I0 whereon the output voltage is changed, an overcurrent, short- circuit current, etc., can be detected.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、零相電流検出器５各種漏れ電流検出器などに
用いられ、鉄心の磁気現象を利用して、主回路とは電気
的に非接触で直流および交流の電流を検出する方法に関
する。[Detailed Description of the Invention] [Field of Industrial Application] The present invention is used in zero-sequence current detectors 5 various leakage current detectors, etc., and utilizes the magnetic phenomenon of the iron core to electrically separate from the main circuit. This invention relates to a method for detecting direct current and alternating current without contact.

〔従来の技術〕[Conventional technology]

電流を主回路とは電気的に非接触で検出する装置は、直
流用としては、直流変流器と、その他に、鉄心にギヤツ
ブを設けてギャップ部にホール素子を挿入する装置があ
り、交流用としては交流変流器が知られている。Devices that detect current without electrical contact with the main circuit include DC current transformers, and devices that install gears on the iron core and insert Hall elements into the gaps. AC current transformers are known for this purpose.

第３４図は、直流変流器の作動を説明するためにその要
部構成を示した模式図である。第３４図のように、直２
ｉｔ変流器は、検出する直流電流■１が流れる導体３を
閉磁路の二つの鉄心１ａ、　ｌｂのそれぞれ中心孔に通
し、鉄心１ａ、　ｌｂに巻回した励硝用コイル２ａと２
ｂを逆向きにして交流電流計４を通し、交流電源５に接
続している。鉄心１ａ、　ｌｂの磁気特性はヒステリシ
ス曲線が角形性を持ち、保持力が小さい材料を用いてい
る。導体３の被検出電流！１がＯのとき、交流電流】は
鉄心１ａ、　ｌｂの励磁電流分のみが流れる。導体３に
直流電流Ｉ、が流れると、鉄心１ａ、　ｌｂの磁束密度
範囲が変わり交流電流ｉが増し、これを交流電流計４で
読み取ることにより直流電流■１を求めることができる
。なお６は主回路の電源、７は同じく負荷を表わす。FIG. 34 is a schematic diagram illustrating the main structure of a DC current transformer to explain its operation. As shown in Figure 34,
The IT current transformer passes the conductor 3 through which the DC current to be detected 1 flows through the center holes of the two iron cores 1a and lb in a closed magnetic circuit, and connects the excitation coils 2a and 2 wound around the iron cores 1a and lb.
b is connected to an AC power source 5 through an AC ammeter 4 in the opposite direction. The magnetic properties of the iron cores 1a and lb are such that the hysteresis curve is square and a material with small coercive force is used. Detected current of conductor 3! When 1 is O, only the excitation current of the iron cores 1a and lb flows in the alternating current. When a direct current I flows through the conductor 3, the magnetic flux density range of the iron cores 1a and lb changes and the alternating current i increases, and by reading this with an alternating current meter 4, the direct current ■1 can be determined. Note that 6 represents the power supply of the main circuit, and 7 similarly represents the load.

第３５図は鉄心とホール素子を用いる装置の要部構成を
示す模式図である。第３５図では鉄心８のギャップにホ
ール素子９を挿入し、ホール素子９に直流電源１０を用
いて直流電流を印加しておき、導体３に被検出電流■１
が流れると鉄心８が磁化され、この磁束によってホール
素子９に電圧が生ずるので、この電圧を直流電圧計１１
で測定することにより直流１ｍ　Ｉ　１　を求めること
ができる。第３５図には主回路の電源と負荷は省略しで
ある。FIG. 35 is a schematic diagram showing the main part configuration of a device using an iron core and a Hall element. In FIG. 35, a Hall element 9 is inserted into the gap of the iron core 8, a DC current is applied to the Hall element 9 using a DC power supply 10, and the detected current ■1 is applied to the conductor 3.
When the flux flows, the iron core 8 is magnetized, and this magnetic flux generates a voltage in the Hall element 9. This voltage is detected by the DC voltmeter 11.
Direct current 1 m I 1 can be determined by measuring with . In FIG. 35, the power supply and load of the main circuit are omitted.

第３６図は交流変流器の要部構成を示す模式図である。FIG. 36 is a schematic diagram showing the main part configuration of an AC current transformer.

この交流変流器は鉄心１２に検出コイル１３を巻回して
あり、検出コイル１３の両端に小抵抗１４を接続し、導
体３は閉ｆ！ｉ路鉄心１２の中心孔を通る。This AC current transformer has a detection coil 13 wound around an iron core 12, a small resistor 14 is connected to both ends of the detection coil 13, and the conductor 3 is closed f! It passes through the center hole of the i-way iron core 12.

導体３に流れる交流電流は、鉄心１２の磁束で生ずる検
出コイル１３の誘起電圧による小抵抗１４両端の電圧降
下分から求めることができる。The alternating current flowing through the conductor 3 can be determined from the voltage drop across the small resistor 14 due to the induced voltage in the detection coil 13 caused by the magnetic flux of the iron core 12.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

近年予防保全が極めて重要視されるようになり、零相電
流検出器は従来の交流用のほかに直流用に対する要望が
強くなっている。しかしながら、前述の装置を用いた電
流検出方法には次のような問題がある。In recent years, preventive maintenance has become extremely important, and there is a strong demand for zero-sequence current detectors for DC use in addition to the conventional AC use. However, the current detection method using the above-mentioned device has the following problems.

直流変流器は被検出電流が０のときも、鉄心のａｍ電流
が流れるため、誤差を生ずるという間脛があり、第３５
図の鉄心のギャップにホール素子を挿入する方法は、周
囲温度の影響が大きく誤差を生しやすいこと、素子部が
構造的に弱く壊れやすいこと、鉄心にギャップがあるた
め、地磁気、近傍に存在する鉄材、電気装置、電線の′
＠流などからの外部磁界によって誤差を生ずることなど
が問題である。また、第３６図の交流変流器は原理的に
直流を検出することができない。DC current transformers have the disadvantage that even when the current to be detected is 0, the am current in the iron core flows, resulting in errors.
The method of inserting a Hall element into the gap in the iron core shown in the figure is highly influenced by the ambient temperature and tends to cause errors, the element part is structurally weak and easy to break, and since there is a gap in the iron core, there are some problems due to the presence of geomagnetism and nearby of iron materials, electrical equipment, and wires
Problems include errors caused by external magnetic fields such as from @ currents. Further, the AC current transformer shown in FIG. 36 cannot detect DC in principle.

本発明は上述の点に鑑みてなされたものであり、その目
的は、外部磁界の影響を受けることなく、交流、直流何
れの電流に対しても検出可能な方法ｆｉ：提（共するこ
とにある。The present invention has been made in view of the above points, and its purpose is to provide a method that can detect both alternating current and direct current without being affected by external magnetic fields. be.

〔課題を解決するための手段］ 上記の課題を解決するために、本発明の方法は、第１の
方法では鉄心の磁気特性が角形ヒステリシスを持つ鉄心
、第２の方法では鉄心の磁気特性が恒ｉ３［率を持つ鉄
心をいずれも２個の閉磁路鉄心として用い、鉄心の励磁
コイルに高抵抗を直列に接続し、被検出電流により鉄心
部のりアクタンスが変化しても励磁電流は変化しない条
件のもとに、鉄心の磁束がほぼ飽和する点まで交流励磁
しておき、被検出電流による磁界は２個の鉄心のうちの
中心に導体を通した一方の鉄心のみに加え、導体を通さ
ない他方の鉄心には加わらないようにし、被検出電流に
よる磁界で導体を通した方の鉄心の磁束密度範囲を変化
させて、その磁束変化で生ずる誘起電圧変化分と、他方
の導体を通さない方の鉄心の誘起電圧との差から主回路
とは電気的に非接触で被検出電流を求めるものである。[Means for Solving the Problems] In order to solve the above-mentioned problems, the method of the present invention includes a first method in which the magnetic characteristics of the iron core have square hysteresis, and a second method in which the magnetic characteristics of the iron core have square hysteresis. Both iron cores with a constant i3 ratio are used as two closed magnetic circuit iron cores, and a high resistance is connected in series to the exciting coil of the iron core, so that even if the actance of the iron core changes due to the detected current, the exciting current does not change. Under these conditions, the core is excited with alternating current until the magnetic flux is almost saturated, and the magnetic field due to the current to be detected is applied only to one of the two cores, with a conductor passed through its center. By changing the magnetic flux density range of the iron core that passes through the conductor using the magnetic field caused by the detected current, the induced voltage change caused by that magnetic flux change and the magnetic flux density range that does not pass through the other conductor. The current to be detected is determined from the difference between the induced voltage of the other iron core and the main circuit without electrical contact.

〔作用） ■本発明における第１の方法は、鉄心に角形ヒステリシ
ス特性を有し、保磁力の小さい材料からなる鉄心を２個
用い、これらを同一波形の一定電流による交流磁界で励
磁する。一方の鉄心は直流交流の被検出電流による磁界
で鉄心の磁界範囲が移動して、保磁力近傍の点で磁束密
度範囲が急激に変化し、この変化により誘起電圧も変化
する。[Operation] (1) The first method of the present invention uses two iron cores made of a material with a rectangular hysteresis characteristic and a small coercive force, and excites them with an alternating current magnetic field with a constant current having the same waveform. In one iron core, the magnetic field range of the iron core moves due to the magnetic field caused by the detected DC/AC current, and the magnetic flux density range changes rapidly at a point near the coercive force, and this change causes the induced voltage to change as well.

他方の鉄心は被検出電流による磁界が加わらないように
しであるので、両鉄心の磁束の差から被検出を流に比例
した出力が得られ、被検出電流を求めることが可能とな
る。Since the other core is designed so that no magnetic field is applied by the current to be detected, an output proportional to the current to be detected can be obtained from the difference in magnetic flux between the two cores, making it possible to determine the current to be detected.

■本発明における第２の方法は、基本的に第１の方法と
同様にして電流を検出することができるが、第２の方法
では鉄心に恒透磁率材料を用いているので、第１の方法
と異なる点は、磁束密度範囲が直線的に変化することで
あり、この変化により生ずる誘起電圧変化分から被検出
電流を求めるものである。■The second method of the present invention can basically detect current in the same way as the first method, but since the second method uses a constant magnetic permeability material for the iron core, it is different from the first method. The difference from this method is that the magnetic flux density range changes linearly, and the detected current is determined from the induced voltage change caused by this change.

〔実施例〕〔Example〕

以下本発明の方法を実施例に基づき説明する。 The method of the present invention will be explained below based on Examples.

はじめに、本発明における第１の方法について説明する
。第１図はこの方法が適用される装置の要部構成の一例
を示した模式図である。第１図において、二つの鉄心１
５ａ、１５ｂは磁気ヒステリシス曲線の保磁力が小さい
材料からなり、例えば環状に形成しである。これら環状
鉄心の一方の鉄心１５８の中心孔を通って、導体１８が
被検出装置の主回路の電源と負荷に接続されているが、
これら電源と負荷は図示を省略しである。鉄心１５ａ、
　１５ｂにはその肉厚部に、交流励磁コイル１６ａ、　
１６ｂを、鉄心部のりアクタンスに比べて大きい抵抗１
９を介して、交流励磁電源２０に接続しである。鉄心１
５ａ、１５ｂには交流励磁コイル１６ａ、１６ｂとは別
に、検出コイル１７ａ、１７ｂを巻回し、増幅器２１ａ
、２１ｂ、両波整流器２２ａ。First, the first method in the present invention will be explained. FIG. 1 is a schematic diagram showing an example of the main structure of an apparatus to which this method is applied. In Figure 1, two iron cores 1
5a and 15b are made of a material whose magnetic hysteresis curve has a small coercive force, and are formed into, for example, annular shapes. The conductor 18 is connected to the power supply and load of the main circuit of the device to be detected through the center hole of the core 158 of one of these annular cores.
These power sources and loads are omitted from illustration. Iron core 15a,
15b has an AC excitation coil 16a in its thick part,
16b is a resistance 1 larger than the glue actance of the iron core.
It is connected to an AC excitation power source 20 via 9. Iron core 1
In addition to AC excitation coils 16a and 16b, detection coils 17a and 17b are wound around 5a and 15b, and an amplifier 21a
, 21b, double-wave rectifier 22a.

２２ｂ、平滑器２３ａ、２３ｂ、減算器２４に接続して
いる。22b, smoothers 23a, 23b, and subtracter 24.

次に第２図は、鉄心１５ａ、１５ｂの磁気ヒステリシス
曲線、第３図〜第６図は鉄心１５ａ、１５ｂの磁束密度
、誘起電圧の波形図、第７図は被検出電流と出力との関
係を示した線図である。Next, Fig. 2 shows the magnetic hysteresis curves of the iron cores 15a and 15b, Figs. 3 to 6 show the magnetic flux density and induced voltage waveforms of the iron cores 15a and 15b, and Fig. 7 shows the relationship between detected current and output. FIG.

以下本発明の第１の方法における作動について、第１図
〜第７図を参照して説明する。The operation of the first method of the present invention will be described below with reference to FIGS. 1 to 7.

鉄心１５ａ、　１５ｂは第１図の交流励磁電源２０と抵
抗１９により励磁する。鉄心の交流印加電圧と磁束密度
、励磁電流、誘起電圧との関係は（１）、　（２）式で
表わすことができる。The iron cores 15a and 15b are excited by an AC excitation power source 20 and a resistor 19 shown in FIG. The relationship between the AC applied voltage to the core, magnetic flux density, exciting current, and induced voltage can be expressed by equations (1) and (2).

ｉ ｔ 但し、ＥＡ　：交流印加電圧 ｉ；交流励１電流 Ｒ１：直列に接続した抵抗１９の値 Ｒｔ　：交流励磁コイル１６ａ、　１６ｂの抵抗の値Ｎ
、：交流励磁コイルの巻数 Ａｃ：Ｍ１１断面積 Ｂ：磁束密度 ｔ：時間 Ｒ３：検出コイル１７ａ、１７ｂの誘起電圧Ｎ、：検出
コイル１７ａ、１７ｂの巻数ここで（３）式のように設
定すると、ＥＡが一定であれば、別のコイルの電流によ
る磁界が加わっても励磁電流ｉは変化しない０本発明は
この条件に設定する。i t However, EA: AC applied voltage i; AC excitation 1 current R1: value of resistor 19 connected in series Rt: value N of resistance of AC excitation coils 16a, 16b
, : Number of turns of AC excitation coil Ac: M11 cross-sectional area B: Magnetic flux density t: Time R3: Induced voltage N of detection coils 17a, 17b, : Number of turns of detection coils 17a, 17b Here, if set as in equation (3) , EA is constant, the excitation current i will not change even if a magnetic field due to the current of another coil is applied. The present invention is set to this condition.

なお、交流励磁電流とは磁界の関係は（４）式、被検出
電流と磁界の関係は（５）式で表わされる。The relationship between the AC excitation current and the magnetic field is expressed by equation (4), and the relationship between the current to be detected and the magnetic field is expressed by equation (5).

Ｈ，＝　（Ｎ＆ｘｉ）　／Ｌ　　　　　・・−・−・・
−・・−・（４）Ｈ，＝　（Ｎ、　ｘ　Ｉ）　／Ｌ　　
　　　−−・−ｍ−−−−−−−−−・−（５）但し、
Ｈム　：交流励磁電流による磁界Ｌ：鉄心の磁路長さ Ｈｏ：被検出電流による磁界 Ｎ１　；導体１８の巻数（通常は１回）鉄心１５ａ、１
５ｂは、被検出電流（導体１８の電流Ｉ）が０の場合、
交流で第２図のＨｌ（Ｂ　ｌ）とＨｍ（Ｂｚ）の範囲で
励磁され、磁束密度Ｂは時間に対して第３図のように変
化する。検出コイル１７ａ、１７ｂの誘起電圧は磁束の
微分であるから、第４図のようなパルス状電圧となり、
両電圧は同じである。H, = (N & xi) /L ・・−・−・・
−・・−・(4) H,= (N, x I) /L
−−・−m−−−−−−−−・−(5) However,
H: Magnetic field due to AC excitation current L: Magnetic path length of the iron core Ho: Magnetic field due to detected current N1; Number of turns of conductor 18 (usually 1) Iron core 15a, 1
5b, when the detected current (current I of conductor 18) is 0,
It is excited with alternating current in the range of Hl (Bl) and Hm (Bz) shown in Fig. 2, and the magnetic flux density B changes with time as shown in Fig. 3. Since the induced voltage in the detection coils 17a and 17b is a differential of the magnetic flux, it becomes a pulse-like voltage as shown in FIG.
Both voltages are the same.

次に導体１８に直流電流１が流れると鉄心１５ａには直
流磁界十１１□が加わり、鉄心１５ａの磁界はＨＩとＲ
５の和になって、第２図のＨｓ、　Ｈ−の範囲で点線の
ようになり、磁束の変化範囲はＢ、〜Ｂ４と小さくなる
。磁束密度Ｂは第５図、検出コイル１７８の誘起電圧波
形は第６図のように小さくなる。Next, when a DC current 1 flows through the conductor 18, a DC magnetic field 111□ is applied to the iron core 15a, and the magnetic field of the iron core 15a becomes HI and R.
5, as shown by the dotted line in the ranges Hs and H- in FIG. 2, and the range of change in magnetic flux becomes small, B, ~B4. The magnetic flux density B becomes small as shown in FIG. 5, and the induced voltage waveform of the detection coil 178 becomes small as shown in FIG.

被検出電流がさらに増すと磁束お変化範囲が急速に滅じ
、検出コイル１７ａの誘起電圧も２減する。When the current to be detected further increases, the range of change in magnetic flux rapidly disappears, and the induced voltage in the detection coil 17a also decreases by two.

検出コイル１７ａ、　１７ｂの誘起電圧を増幅器２１ｇ
、２１ｂで増幅し、これを両波整流器２２ａ、　２２ｂ
、平滑器２３ａ２３ｂ、減算器２４を通すと、誘起電圧
の差に比例したの点て急増する。この出力電圧が変化す
る点を利用して遇ｔ′ｔｌＬ、漏電電流などを検出する
ことができる。The induced voltage of the detection coils 17a and 17b is transferred to the amplifier 21g.
, 21b, which is then amplified by both wave rectifiers 22a and 22b.
, the smoother 23a23b, and the subtracter 24, the voltage increases rapidly in proportion to the difference in induced voltage. Utilizing this point at which the output voltage changes, it is possible to detect occurrences of t'tlL, leakage current, and the like.

１、の値は第２図のＨｒ　、　Ｈｔ　と鉄心材料の保磁
力Ｈ３の値によって決まり、交流電圧ＥＡ＋交流励磁コ
イル１６ａ、１６ｂの巻数、抵抗１９により任意に設定
することができるが、最小値は鉄心１５ａ、　１５ｂの
保磁力Ｈｃによるので、零相電流のような小電流を検出
するには、鉄心１５ａ、　１５ｂに保磁力Ｈｃの小さい
材料を用いる必要がある。The value of 1 is determined by the values of Hr and Ht in Fig. 2 and the coercive force H3 of the iron core material, and can be arbitrarily set by the AC voltage EA + the number of turns of the AC excitation coils 16a and 16b, and the resistor 19, but the minimum value is due to the coercive force Hc of the iron cores 15a, 15b, so in order to detect a small current such as a zero-sequence current, it is necessary to use a material with a small coercive force Hc for the iron cores 15a, 15b.

ここでは誘起電圧を整流、平滑する方法について説明し
たが、誘起電圧を積分器に入れ、磁束波形にする方法で
もよいことは勿論である。Although a method of rectifying and smoothing the induced voltage has been described here, it goes without saying that a method of inputting the induced voltage into an integrator to form a magnetic flux waveform may also be used.

交流励磁電源２０に商用周波数電源を用いると直流を検
出することができ、高周波電源を用いると交直両用の電
流検出が可能となる。高周波励磁の周波数は被検出電流
の１０倍以上が望ましく、例えば、被検出電流の周波数
が５０Ｈｚであれば５００８Ｚ以上、Ｉ　ＫＨｚであれ
ば１０）［Ｈｚ以上とする。鉄心１５ａ。If a commercial frequency power source is used as the AC excitation power source 20, direct current can be detected, and if a high frequency power source is used, it is possible to detect both AC and DC currents. The frequency of high-frequency excitation is desirably 10 times or more of the current to be detected; for example, if the frequency of the current to be detected is 50 Hz, it is 5008 Z or more, and if the frequency of the current to be detected is I KHz, it is 10) [Hz or more. Iron core 15a.

１５ｂの励磁状態は磁束、磁界の速度が大きくなるのみ
で基本的には第１図の装置を用いた方法と同じである。The excitation state of 15b is basically the same as the method using the apparatus shown in FIG. 1, except that the magnetic flux and the speed of the magnetic field are increased.

検出コイル１７ａ、　１７ｂの誘起電圧はパルスの幅が
せまくなるので、積分器を用いて磁束波形に戻して方形
波にし、ピークホールド器を通し、以後の信号処理は前
述の方法と同じである。高周波励磁電源の波形は正弦波
でなくても、方形波など他の波形でもよい。Since the pulse width of the induced voltage of the detection coils 17a and 17b becomes narrow, an integrator is used to return the magnetic flux waveform to a square wave, which is then passed through a peak hold device.The subsequent signal processing is the same as the method described above. The waveform of the high-frequency excitation power source does not have to be a sine wave, but may be another waveform such as a square wave.

検出部の構成を部品にして、より小型化するために、検
出コイル１７ａ、１７ｂを鉄心１５ａ、　１５ｂに巻く
のではなく、交流励磁コイル１６ａ、　１６ｂの両端か
ら取り出すことも可能である。その装置の要部の構成を
第８図に示す、第８図の場合、交流励磁コイル１６ａ、
１６ｂの両端の電圧は、（１）式の第２項と第３項の和
になるが、第２項の値を第３項に比べて非常に小さく設
定すれば第２項は無視することができ、第１図の検出コ
イル１７ａ、１７ｂの誘起電圧と同等と見做すことがで
きる。即ち交流励磁コイルｔ６ａ＋１６ｂの両端の電圧
から直流電流を検出することができる。In order to reduce the size of the detection section by making it a component, it is also possible to take out the detection coils 17a and 17b from both ends of the AC excitation coils 16a and 16b instead of winding them around the iron cores 15a and 15b. The configuration of the main parts of the device is shown in FIG. 8. In the case of FIG. 8, an AC excitation coil 16a,
The voltage across 16b is the sum of the second and third terms in equation (1), but if the value of the second term is set very small compared to the third term, the second term can be ignored. can be considered to be equivalent to the induced voltage of the detection coils 17a and 17b in FIG. That is, the DC current can be detected from the voltage across the AC excitation coil t6a+16b.

第８図の装置でも前述と同様、交流励磁電源２０に高周
波電源、出力側に積分器、ピークホールド器を用いるこ
とにより、交流電流も検出することが可能である。The apparatus shown in FIG. 8 can also detect alternating current by using a high frequency power source as the alternating current excitation power source 20 and an integrator and a peak hold device on the output side, as described above.

以上本発明の第１の電流検出方法と作動について、基本
的な事柄を説明した０次にこの方法を用いた具体的な事
例を再び第１図と第８図を参照して述べる。鉄心は保磁
力が小さい材料で、組成が８２Ｃｏ−２Ｎ＋−４，５Ｆ
ｅ−８，５５ｉ−３８のアモルファス合金薄帯を円筒状
の巻鉄心に形成し、所定の熱処理を行なった後、プラス
チックケースに入れた。このアモルファス合金は直流は
勿論、高周波の磁気特性が優れている上に、磁歪が小さ
いので磁気特性に対する影響も小さく、取り扱いが容易
であり鉄心１５ａ、　１５ｂとして用いるには好適であ
る。鉄心１５ａ。Having explained the basic matters regarding the first current detection method and operation of the present invention, a specific example using this method will be described again with reference to FIGS. 1 and 8. The iron core is made of a material with low coercive force and has a composition of 82Co-2N+-4,5F.
An amorphous alloy ribbon of e-8 and 55i-38 was formed into a cylindrical wound core, subjected to a prescribed heat treatment, and then placed in a plastic case. This amorphous alloy has excellent magnetic properties not only in direct current but also in high frequency waves, has low magnetostriction, has little effect on magnetic properties, and is easy to handle, making it suitable for use as iron cores 15a and 15b. Iron core 15a.

１５ｂの寸法は外径３７■、内径３５■５高さ（薄帯の
幅）２ｍｓである０例えば第１図の装置構成で交流励磁
電源２０は商用電源１００　Ｖ　、　５０Ｈ２を用いた
場合について述べる。電子回路部は部品な汎用ＩＣによ
り作製した。交流励磁コイル１６ａ、　１６ｂは直径０
．１１のホルマール銅線を用いた。この方法で直流電流
を検出した結果を第９図１第１０図に示す。The dimensions of 15b are outer diameter 37 cm, inner diameter 35 cm, height (width of the ribbon) 2 ms, etc.For example, in the device configuration shown in Fig. 1, the AC excitation power source 20 is a commercial power source of 100 V, 50 H2. . The electronic circuit section was fabricated using general-purpose IC components. AC excitation coils 16a and 16b have a diameter of 0
．． No. 11 formal copper wire was used. The results of detecting direct current using this method are shown in FIG. 9 and FIG. 10.

第９図は５０ｍＡ、第１０図は１００　Ａに設定した場
合である０両特性とも設定点で正確に出力電圧が現われ
、直流の零相電流検出器、過電流検出器に適用できるこ
とがわかる。FIG. 9 shows the case where the setting is 50 mA, and FIG. 10 shows the case where the setting is 100 A. In both characteristics, the output voltage appears accurately at the set point, and it can be seen that it can be applied to a DC zero-sequence current detector and an overcurrent detector.

次に交流励磁電源２０に高周波電源を用いた場合につい
て述べる。高周波を源は汎用ＩＣで作製し、正弦波ＩＫ
Ｈｚ、１１ｉ圧１０Ｖである。電子回路部も節易な汎用
ＩＣにより作製した。交流励磁コイル１６ａ１６ｂは直
径０．１ｍｓのホルマール銅線を用いた。この方法で交
１５０Ｈｚの電流を検出した結果を第１１図第１２図に
示す、第１１図は５０ｍＡ、第１２図はＩＡに設定した
場合である。この場合も設定点で出力電圧が生じ、零相
を流検出器に通用することができる。Next, a case will be described in which a high frequency power source is used as the AC excitation power source 20. The high frequency source is made with a general-purpose IC, and the sine wave IK
Hz, 11i pressure, 10V. The electronic circuit section was also fabricated using an easy-to-use general-purpose IC. A formal copper wire with a diameter of 0.1 ms was used for the AC excitation coil 16a16b. The results of detecting an AC current of 150 Hz using this method are shown in FIGS. 11 and 12. FIG. 11 shows the case where the current was set to 50 mA, and FIG. 12 shows the case where the current was set to IA. Again, an output voltage is produced at the set point, allowing the zero phase to pass to the current detector.

ここまでは、本発明の第１の方法の原理的な事項、およ
びその具体的な使用例などについて述べてきたが、以後
第２の方法について説明する。Up to this point, the principle of the first method of the present invention and its specific example of use have been described, and the second method will be described below.

第１３図は第２の方法に適用される装置の要部の構成を
示す模式図であり、第１図と共通部分を同一符号で表わ
しである。第１３図において、鉄心１５ｃ。FIG. 13 is a schematic diagram showing the configuration of main parts of an apparatus applied to the second method, and parts common to those in FIG. 1 are represented by the same symbols. In FIG. 13, the iron core 15c.

１５ｄは恒速磁率で磁気ヒステリシス曲線の保磁力が小
さい材料からなり、閉磁路の例えば環状に形成したもの
である。交流励磁側の回路構成は、第１図の第１の方法
と全く同じであるからその説明を省略する。検出側は鉄
心１５ｃ、　１５ｄに交流励磁コイル１６ａ、１６ｂと
は別に検出コイル１７ａ、１７ｂを巻回し、両波整流器
２２ａ、２２ｂ、平滑器２３ａ、２３ｂ、減算器２４を
接続する。15d is made of a material with a constant magnetic rate and a small coercive force in a magnetic hysteresis curve, and is formed into a closed magnetic path, for example, in an annular shape. The circuit configuration on the AC excitation side is exactly the same as the first method shown in FIG. 1, so its explanation will be omitted. On the detection side, detection coils 17a and 17b are wound around iron cores 15c and 15d separately from AC excitation coils 16a and 16b, and double-wave rectifiers 22a and 22b, smoothers 23a and 23b, and subtractor 24 are connected.

第１４図は鉄心１５ｃ、　１５ｄの磁気ヒステリシス曲
線、第１５図〜第１８図は磁束密度、誘起電圧の波形、
第１９図は被検出電流と出力との関係を示した線図であ
る。Fig. 14 shows magnetic hysteresis curves of iron cores 15c and 15d, Figs. 15 to 18 show magnetic flux density and induced voltage waveforms,
FIG. 19 is a diagram showing the relationship between detected current and output.

以下、本発明の第２の方法における作動について、第１
３図〜第１９を参照して説明する鉄心１５ｃ、　１５ｄ
は第１３図の交流励磁電源２０と抵抗１９により励磁す
る。交流励磁電源２０は低周波と高周波では被検出電流
の周波数範囲が異なるが、まず低周波の商用ｔｆｉ（正
弦波５０．６０８２）の場合について述べる。鉄心１５
ｃ、１５ｄの交流印加電圧、磁束密度、励磁電流。Hereinafter, the operation in the second method of the present invention will be explained as follows.
Iron cores 15c and 15d explained with reference to Figures 3 to 19
is excited by the AC excitation power supply 20 and resistor 19 shown in FIG. Although the frequency range of the current to be detected in the AC excitation power supply 20 is different between low frequency and high frequency, the case of low frequency commercial TFI (sine wave 50.6082) will be described first. iron core 15
c, AC applied voltage, magnetic flux density, and excitation current of 15d.

磁界および誘起電圧などは、既に第１の方法で述べた（
１）〜（５）式と同じであるから、ここではこれらの式
の記載は省略する。The magnetic field and induced voltage have already been described in the first method (
Since they are the same as equations 1) to (5), description of these equations will be omitted here.

鉄心１５ｃ、１５ｄは、被検出電流（導体１８の電流）
がＯのときは、交流で第１４図のＨ、ＣＢ　＋）とＨ、
（Ｂ　、）の範囲で励磁され、磁束密度Ｂは時間に対し
て第１５図ように変化する。検出コイル１７ａ、１７ｂ
の誘起電圧は磁束の微分であるから第１６図ような電圧
波形となる０次に導体１８に直流電流■が流れると、鉄
心１５ｃには直流磁界子Ｈ１が加わって、磁界はＨｉ　
とＨｌの和になり、第１４図のＨｓ（Ｂ＋）、Ｈ。The iron cores 15c and 15d are the current to be detected (current in the conductor 18)
When is O, H, CB +) and H in Fig. 14 with alternating current,
It is excited in the range of (B,), and the magnetic flux density B changes with time as shown in FIG. Detection coils 17a, 17b
Since the induced voltage is the differential of the magnetic flux, it has a voltage waveform as shown in FIG. 16. When a DC current ■ flows through the zero-order conductor 18, a DC magnetic field H1 is applied to the iron core 15c, and the magnetic field becomes Hi.
and Hl, and Hs(B+) and H in Figure 14.

（Ｂ、）の範囲に移動して磁束の変化範囲が小さくなる
。第１４図中のＨｌｌはＩとＢの関係が直線にならない
範囲である。ｖＬ磁束密度第１７図になって、検出コイ
ル１７ａの誘起電圧波形は第１８図のように小さくなる
。被検出電流がさらに増すと磁束の変化範囲は被検出電
流による磁界に対して直線的に低減し、検出コイル１７
ａの誘起電圧も小さくなり、検出コイル１７ａ、　１７
ｂの誘起電圧を両波整流器２２ａ２２ｂ、平滑器２３ａ
、２３ｂ、減算器２４を通すと誘起電圧に比例した直流
電圧になる。被検出電流と減算器２４の出力電圧との関
係は第１９図のようになり、被検出電流１が０とＩｌの
範囲では曲線状になるが、１１と１！の範囲では直線状
になる。被検出電流と出力の関係が低電流側で曲線状と
なるのは、第１４図のＨｌとＨ３の間では磁気ヒステリ
シス曲線が曲線状を呈するからである。ここでは被検出
電流が正の場合について述べたが、負の場合も同様であ
る。As the magnetic flux moves to the range (B,), the range of change in magnetic flux becomes smaller. Hll in FIG. 14 is a range in which the relationship between I and B is not a straight line. When the vL magnetic flux density reaches FIG. 17, the induced voltage waveform of the detection coil 17a becomes small as shown in FIG. 18. When the current to be detected further increases, the range of change in magnetic flux decreases linearly with respect to the magnetic field due to the current to be detected, and the detection coil 17
The induced voltage of a also decreases, and the detection coils 17a, 17
The induced voltage of
, 23b, and the subtracter 24, it becomes a DC voltage proportional to the induced voltage. The relationship between the current to be detected and the output voltage of the subtractor 24 is as shown in FIG. 19, and the current to be detected 1 is curved in the range of 0 and Il, but in the range of 11 and 1! It becomes linear in the range of . The reason why the relationship between the current to be detected and the output is curved on the low current side is because the magnetic hysteresis curve is curved between H1 and H3 in FIG. Although the case where the current to be detected is positive has been described here, the same applies to the case where the current to be detected is negative.

ここでは誘起電圧を整流して平滑する方法について説明
したが、勿論、誘起電圧をピークホールド器に入れて直
流に変換する方法、誘起電圧を積分器を通して磁束波形
に変換してピークホールド器に入れる方法などを用いて
もよい。Here, we have explained how to rectify and smooth the induced voltage, but of course there is also a method of converting the induced voltage into a direct current by putting it into a peak hold device, and a method of converting the induced voltage into a magnetic flux waveform through an integrator and putting it into a peak hold device. method etc. may be used.

第２の方法も前述の第１の方法と同様、検出部の構成を
ＰＪ５にして、より小型な装置とすることができ、その
装置の要部構成模式図を第２０図に示す、この場合も基
本的には第１の方法における第８図に示したものと同じ
でるから、説明は省略する。Similarly to the first method described above, the second method also allows the configuration of the detection section to be PJ5, resulting in a more compact device. Since this is basically the same as that shown in FIG. 8 in the first method, the explanation will be omitted.

さらに、第２の方法は第１の方法と同様に、交流励磁電
ｆｉ２０に商用周波数電源を用いると直流、高周波電源
を用いると交流を検出することが可能である。Furthermore, in the second method, like the first method, it is possible to detect direct current when a commercial frequency power source is used for the AC excitation electric fi 20, and to detect alternating current when a high frequency power source is used.

第２１図は本発明の第２の方法において、これまでと異
なる励磁条件として電流を検出する方法を説明するため
に、その装置の要部構成を示したものである。第２１図
において、交流励磁コイル１６ａ１６ｂ、制御抵抗１９
と直列に半波整流器２５を接続し、その他の装置構成は
第１３図と同しである。第２２図は第２１図の装置によ
り励磁したときの鉄心１５ｃ、１５ｄの磁気ヒステリシ
ス曲線である。鉄心１５ｃ、　１５ｄの励磁は前述の（
３）式の条件で行なう。鉄心１５ｃ、　１５ｄは、被検
出電流が０のとき、交流で第２２図のｆｌ（Ｂ、、）と
）１゜（Ｂ　Ｉりの範囲で励磁され、磁束密度Ｂは第２
３図、検出コイル１７ａ、１７ｂの誘起電圧は（２）式
により第２４図の波形になる。導体１８に正の直流電流
＋１が流れると、鉄心１５ｃには直流磁界子Ｈ１が加わ
り、励磁範囲はＨＩ３（Ｂ１１）とＨ（Ｂ、４）となっ
て磁束密度変化範囲が小さくなり、第２５図、第２６図
に示す如く磁束密度、誘起電圧が小さくなる。導体１日
に負の直流電流−■が流れると、励磁範囲はＨ３ｓ（Ｂ
＋＋）とＨｉａ（Ｂ＋−）となって磁束密度変化範囲が
大きくなり、第２７図、第２８図のように磁束密度、誘
起電圧が大きくなる。FIG. 21 shows the configuration of a main part of the device in order to explain a method of detecting current as an excitation condition different from the conventional method in the second method of the present invention. In FIG. 21, AC excitation coil 16a16b, control resistor 19
A half-wave rectifier 25 is connected in series with , and the other device configuration is the same as that in FIG. FIG. 22 shows magnetic hysteresis curves of the cores 15c and 15d when excited by the device shown in FIG. 21. The excitation of the iron cores 15c and 15d is as described above (
3) Perform under the conditions of formula. When the current to be detected is 0, the iron cores 15c and 15d are excited with alternating current in a range of fl(B, ,) in FIG.
In FIG. 3, the induced voltage in the detection coils 17a and 17b has a waveform as shown in FIG. 24 according to equation (2). When a positive DC current +1 flows through the conductor 18, a DC magnetic field H1 is applied to the iron core 15c, the excitation range becomes HI3 (B11) and H (B, 4), the magnetic flux density change range becomes smaller, and the 25th As shown in FIG. 26, the magnetic flux density and the induced voltage become smaller. When a negative DC current -■ flows through the conductor for 1 day, the excitation range becomes H3s (B
++) and Hia (B+-), the range of change in magnetic flux density increases, and the magnetic flux density and induced voltage increase as shown in FIGS. 27 and 28.

第２２図の各条件において、第２１図の検出コイル１７
ａ１７ｂの誘起電圧を両波整流器２２ａ、２２ｂ、平滑
器２３ａ２３ｂ、　ｉ％ｉ算器２４を通すと誘起電圧に
比例した直流電圧が得られる。導体１８の被検出電流と
減算器２４の出力との関係線図を第２９図に示す。Under each condition of FIG. 22, the detection coil 17 of FIG.
When the induced voltage of a17b is passed through the double-wave rectifiers 22a, 22b, the smoother 23a23b, and the i%i calculator 24, a DC voltage proportional to the induced voltage is obtained. A relationship diagram between the detected current of the conductor 18 and the output of the subtracter 24 is shown in FIG.

また、第２１図の装置は検出コイル１７ａ、１７ｂを省
略し、かつ交流励磁電源２０を低周波（商用）にも高周
波にもすることが可能であることは、これまで述べた第
１．第２の方法を含む全ての方法と同じである。In addition, the device shown in FIG. 21 can omit the detection coils 17a and 17b, and the AC excitation power source 20 can be set to either a low frequency (commercial) or a high frequency, as described in the above-mentioned 1. The same applies to all methods, including the second method.

以上本発明の第２の方法の装置と作動について基本的な
事項を説明した。ここで第２の方法を用いた具体的な実
例を再び第１３図３第２０図、第２１図を参照して述べ
る。鉄心１５ｃ、１５ｄは市販ＯＣＯ系アモルファス合
金薄帯の巻鉄心であり、バキュウムシュメルツ社製の商
品記号６０２５Ｆと６０３０１１を用い、鉄心１５ａの
寸法は外形２５日、内径２０ａｍ、高さ（′ｉｉｉ帯の
幅）　１０ｍｍである。The basic matters regarding the apparatus and operation of the second method of the present invention have been explained above. Here, a concrete example using the second method will be described again with reference to FIGS. 13, 3, 20, and 21. The iron cores 15c and 15d are wound cores made of commercially available OCO-based amorphous alloy thin strips, and have product codes 6025F and 603011 manufactured by Vacuum Schmerz. width) is 10mm.

まず、第１３図の装置構成で直流電流を検出した結果に
ついて述べる。鉄心１５ｃ、　１５ｄは上述の６０３０
Ｆを用い、交流励磁コイル１６ａ、１６ｂの巻数が１５
０回、検出コイル１７ａ、１７ｂの巻数が４０回である
０両波整流器２２ａ　、　２２ｂはオペアンプと整流器
を用い、理想整流回路として低電圧でも正確に整流でき
るようにした。平滑器２３ａ　、　２３ｂはコンデンサ
と抵抗を用いた回路であり、減算器２４もオペアンプに
よる回路である。交流励磁電源２０は商用電源のｔｏｏ
ｖ、　ｓ。First, the results of detecting direct current using the device configuration shown in FIG. 13 will be described. Iron cores 15c and 15d are 6030 mentioned above.
F, and the number of turns of AC excitation coils 16a and 16b is 15.
The zero-wave rectifiers 22a and 22b, in which the number of turns of the detection coils 17a and 17b is 40, use an operational amplifier and a rectifier, and are designed as ideal rectifier circuits that can accurately rectify even low voltages. The smoothers 23a and 23b are circuits using capacitors and resistors, and the subtracter 24 is also a circuit using an operational amplifier. The AC excitation power supply 20 is a commercial power supply too
v, s.

Ｈｚである。第３０図は被検出電流と出力電圧との関係
を示す線図であり、第３０図中の特性線（イ）、＠。It is Hz. FIG. 30 is a diagram showing the relationship between detected current and output voltage, and characteristic lines (A) and @ in FIG.

（ハ）はそれぞれ交流励磁電流による最大磁界を２５Ｏ
Ａ／ｍ５００Ａ／霧、１０００Ａ／−とした場合を表わ
している。第３０図から被検出電流と出力電圧が直線関
係にある領域で、信号として十分な大きさを持っており
、検出電流範囲を任意に設定することが可能である。(C) is the maximum magnetic field due to AC excitation current of 25O
The case where A/m is 500 A/fog and 1000 A/- is shown. As can be seen from FIG. 30, in the region where the current to be detected and the output voltage are in a linear relationship, it has a sufficient magnitude as a signal, and the detection current range can be arbitrarily set.

第３１図は第２１図の装置構成で鉄心１５ｃ、　１５ｄ
に上述の６０２５Ｆを用い、交流励磁コイル１６ａ、　
１６ｂの巻数が１００回、交流励磁電源２０は１００Ｖ
、５０Ｈｚとしたときの被検出電流と出力電圧との関係
を示す線図である。第３１図中の特性、ｉｌｌ、（ロ）
、　ＰＮは交流励磁電流による最大磁界をそれぞれ２Ａ
／■、ＩＯＡ／ｓ＋、２０Ａ／ｍとした場合を表わす、
この方法は数十−＾から数Ａの小さい直流電流を検出す
るのに適している。Figure 31 shows the device configuration shown in Figure 21 with iron cores 15c and 15d.
Using the above-mentioned 6025F, the AC excitation coil 16a,
The number of turns of 16b is 100, and the AC excitation power supply 20 is 100V.
, 50Hz is a diagram showing the relationship between detected current and output voltage. Characteristics in Figure 31, ill, (b)
, PN is the maximum magnetic field due to the AC excitation current of 2A, respectively.
/■, IOA/s+, 20A/m,
This method is suitable for detecting small direct currents of several tens of amperes to several amps.

第３２図に第２１図の装置構成で直流電流を検出した場
合の被検出電流と出力電圧と関係線図を示した。前述の
ように鉄心および装置の構成は、交流励磁電流波形を半
波整流Ｆｉｉ２５を用いて半波にした以外は第１３図の
場合と同しである。交流励磁による最大磁界は６００Ａ
／ｍである。第３２図において、±１５Ａ〜−１５＾の
範囲で直線性が非常によいことがわかる。ただ、この電
流検出範囲は鉄心１５ｃ、１５ｄの寸法、材料特性で決
まり、任意に設定することはできない。FIG. 32 shows a relationship diagram between detected current and output voltage when direct current is detected with the device configuration shown in FIG. 21. As mentioned above, the configuration of the iron core and the device is the same as that shown in FIG. 13 except that the AC excitation current waveform is made half-wave by using the half-wave rectifier Fii 25. Maximum magnetic field due to AC excitation is 600A
/m. In FIG. 32, it can be seen that the linearity is very good in the range of ±15A to -15^. However, this current detection range is determined by the dimensions and material properties of the iron cores 15c and 15d, and cannot be set arbitrarily.

第３３図は第２１図の装置構成における検出コイル１７
ａ、　１７ｂを省き、交流励磁コイル１６ａ、１６ｂの
両端から信号を取り出して、直流電流を検出したときの
被検出電流と出力電圧との関係を表わす線図である。交
流励磁の磁界は２．５４／＊である。この方法では被検
出電流の正負を検出することができ、零相電流のような
微小電流を検出するのに適している。FIG. 33 shows the detection coil 17 in the device configuration of FIG. 21.
It is a diagram showing the relationship between detected current and output voltage when direct current is detected by omitting signals a and 17b and extracting signals from both ends of alternating current excitation coils 16a and 16b. The magnetic field of AC excitation is 2.54/*. This method can detect whether the current to be detected is positive or negative, and is suitable for detecting minute currents such as zero-sequence currents.

〔発明の効果］ 従来、導体を流れる直流電流を検出するとき、周囲温度
や外部磁界の影響などを受けやすいものであったが、本
発明の方法によれば実施例で述べた如く、鉄心に角形ヒ
ステリシス特性を持つ材料または恒速磁率を持つ材料を
２個用いて、これら鉄心に巻回した励磁コイルに抵抗を
直列に接続し、鉄心の磁束がほぼ飽和する点まで交流励
磁しておき、一方の鉄心の中心孔を通る導体を流れる被
検出電流による鉄心の磁束密度変化を象、激に、または
直線的に緩やかに起こさせて、その磁束密度変化で生ず
る誘起電圧変化分を励磁コイルとは別に巻いた検出コイ
ルから取り出し、出力のＯの点は他方の鉄心の検出コイ
ルで補償して、Ｔｉ流の検出を行なうようにしたため、
直流電流の検出は大電流まで外部磁界の影響が小さく、
周囲温度の影響も掻めて少なく、したがって高い精度で
電流を検出することができる０以上のことから、本発明
の方法によれば過電流検出器など各種の直流装置の製作
が可能となり、また零相電流のような微小電流はこれま
で交流しか検出することができなかったのに対して、直
流の零相電流の検出も可能である。即ち本発明によれば
交直両用の高精度の小型電流検出装置を得ることができ
る。[Effects of the Invention] Conventionally, when detecting direct current flowing through a conductor, it was easily affected by ambient temperature and external magnetic fields, but according to the method of the present invention, as described in the embodiment, Using two materials with rectangular hysteresis characteristics or materials with constant magnetic flux, a resistor is connected in series to the excitation coils wound around these iron cores, and AC excitation is carried out until the magnetic flux of the iron core is almost saturated. The magnetic flux density change of the iron core caused by the detected current flowing through the conductor passing through the center hole of one of the iron cores is caused to occur sharply or linearly, and the induced voltage change caused by the magnetic flux density change is applied to the exciting coil. is taken out from a separately wound detection coil, and the output point O is compensated by the detection coil of the other core to detect the Ti flow.
Direct current detection is less affected by external magnetic fields up to large currents.
The influence of the ambient temperature is also very small, and therefore the current can be detected with high accuracy (0 or more), so the method of the present invention makes it possible to manufacture various DC devices such as overcurrent detectors, and also Until now, only alternating current could be detected for minute currents such as zero-sequence current, but direct current zero-sequence current can also be detected. That is, according to the present invention, it is possible to obtain a highly accurate compact current detection device for both AC and DC applications.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の第１の方法に用いる装置の要部構成を
示す模式図、第２図は第１図の装置に用いる鉄心の磁気
ヒステリシス曲線図、第３図、第５図は第１図の装置に
おける時間−磁束密度線図、第４図、第６図は同しく時
間−誘起電圧波形線図、第７図は第１図の装置における
被検出電流−減算器出力電圧線図、第８図は本発明の第
１の方法に適用され第１図とは異なる装置構成を示す模
式図、第９図は商用電源を用いたときの本発明の第１の
方法により得られる５０−＾の被検出電流−出力電圧線
図、第１０図は同しく　　１００Ａの被検出電流−出力
電圧線図、第１１図は高周波を源を用いたときの本発明
の第１の方法により得られる５０Ｈｚ、　５０ｍＡの被
検出電流−出力電圧線図、第１２図は同しくＩＡの被検
出電流−出力電圧線図、第１３図は本発明の第２の方法
に用いる装置の要部構成を示す模式図、第１４図は第１
３図の装置に用いる鉄心の磁気ヒステリシス曲線図、第
１５図、第１７図は第１３図の装置における時間−磁束
密度線図、第１６図、第１８図は同しく時間−誘起電圧
波形線図、第１９図は第１３図の装置における被検出電
流−減算器出力電圧線図、第２０図は本発明の第２の方
法に適用され第１３図とは異なる装置構成を示す模式図
、第２１図は本発明の第２の方法に用いられ第１３図の
装置の励磁回路側に半波整流器を接続したときの構成を
示す模式図、第２２図は第２１図の装置で励磁した鉄心
の磁気ヒステリシス曲線図、第２３図は第２１図の装置
における図の装置に正の直流電流が流れたときの時間−
磁束密度線図、第２６図は同じく時間−誘起電圧波形線
図、第２７図は第２１図の装置に負の直流電流が流れた
ときの時間−磁束密度線図、第２８図は同じく時間−誘
起電圧波形線図、第２９図は第２１図の装置における被
検出電流−減算器出力電圧線図、第３０図は第１３図の
装置における最大磁界を２５ＯＡ／ｍ。 ５００Ａ／ｍ、　１００ＯＡ／Ｉｌｌとしたときの被検
出電流−出力電圧線図、第３１図は第２０図の装置にお
ける最大磁界を２Ａ／ａ、　ＩＯＡ／ｓ、　２０Ａ／＋
＋としたときの被検出電流−出力電圧線図、第３２図は
第２１図の装置における被検出電流−出力電圧線図、第
３３図は第２１図の装置における交流励磁コイル両端か
ら出力を取りだしたときの被検出電流−出力電圧線図、
第３４図は直流変流器の要部構成を示す模式図、第３５
図は鉄心とホール素子を用いた電流検出装置の要部構成
を示す模式図、第３６図は交流変流器の要部構成を示す
模式図である。 ｌａ＋　ｌｂ、　８＋　１２＋　１５ａ、　１５ｂ、　
１５ｃ、　１５ｄ　：鉄心、２ａ、２ｂ　　：励磁コイ
ル、３．ｔ８：導体、４；交流電流針、５：交流電源、
６：主回路の電源、７：主回路の負荷、９；ホール素子
、ｌＯ：直流電源、ｌｌ：直流電圧針、１３．１７ａ、
　１７ｂ　：検出コイル、１６ａ、１６ｂ　　；交流励
磁コイル、１９：抵抗、２〇二交流励磁電源、２１ａ、
２１ｂ　　：増幅器、２２ａ、２２ｂ　　：両波整流器
、２３ａ。 第１図 日１ 第２ｅｌ 第 図 第 図 第 図 第 図 ＭＬ檜酢電λ 第 図 流昇 第１４１ 第 図 第 図 第１０図 第１１１ 第１２ 図 第１５図 第１７図 第１６図 第１８図 第１９図 ＃＆穫ｉ、ｌｊ２を 第２９図 第２４図 第２８図 第２１図 ふ肱界 禮種北１１汽直流（Ａ＞ 第３０図 禮檜工側だ、１５訂Ａ） 第３１図 第３４図 第３５図 第３６図Fig. 1 is a schematic diagram showing the main part configuration of the device used in the first method of the present invention, Fig. 2 is a magnetic hysteresis curve diagram of the iron core used in the device of Fig. 1, and Figs. 1 is a time-magnetic flux density diagram, FIGS. 4 and 6 are time-induced voltage waveform diagrams, and FIG. 7 is a detected current-subtractor output voltage diagram for the device in FIG. 1. , FIG. 8 is a schematic diagram showing a device configuration applied to the first method of the present invention and different from that in FIG. 1, and FIG. Figure 10 shows the detected current-output voltage diagram of -^, and Figure 11 shows the detected current-output voltage diagram of 100A obtained by the first method of the present invention when using a high frequency source. Figure 12 is a detected current-output voltage diagram of IA at 50 Hz and 50 mA, and Figure 13 shows the main part configuration of the device used in the second method of the present invention. The schematic diagram shown in Fig. 14 is the first
The magnetic hysteresis curve of the iron core used in the device shown in Figure 3, Figures 15 and 17 are time-magnetic flux density diagrams for the device shown in Figure 13, and Figures 16 and 18 are time-induced voltage waveform lines. 19 is a detected current-subtractor output voltage diagram in the device shown in FIG. 13, and FIG. 20 is a schematic diagram showing a device configuration applied to the second method of the present invention and different from that shown in FIG. 13. Fig. 21 is a schematic diagram showing the configuration when a half-wave rectifier is connected to the excitation circuit side of the device shown in Fig. 13 used in the second method of the present invention, and Fig. 22 is a schematic diagram showing the configuration when excited by the device shown in Fig. 21. The magnetic hysteresis curve diagram of the iron core, Fig. 23 shows the time when a positive DC current flows through the device shown in the figure in the device shown in Fig. 21.
Figure 26 is a time-induced voltage waveform diagram, Figure 27 is a time-magnetic flux density diagram when a negative DC current flows through the device in Figure 21, and Figure 28 is a time-magnetic flux density diagram. - Induced voltage waveform diagram; FIG. 29 is a detected current-subtractor output voltage diagram in the device shown in FIG. 21; and FIG. 30 shows the maximum magnetic field of 25 OA/m in the device shown in FIG. Detected current-output voltage diagram when 500A/m, 100OA/Ill, Figure 31 shows the maximum magnetic field in the device in Figure 20 of 2A/a, IOA/s, 20A/+
Figure 32 is a detected current-output voltage diagram for the device shown in Figure 21, and Figure 33 is a diagram showing the output from both ends of the AC excitation coil in the device shown in Figure 21. Detected current vs. output voltage diagram when taken out,
Figure 34 is a schematic diagram showing the main part configuration of a DC current transformer, Figure 35
The figure is a schematic diagram showing the main part structure of a current detection device using an iron core and a Hall element, and FIG. 36 is a schematic diagram showing the main part structure of an AC current transformer. la+ lb, 8+ 12+ 15a, 15b,
15c, 15d: Iron core, 2a, 2b: Excitation coil, 3. t8: conductor, 4: alternating current needle, 5: alternating current power supply,
6: Main circuit power supply, 7: Main circuit load, 9: Hall element, lO: DC power supply, ll: DC voltage needle, 13.17a,
17b: Detection coil, 16a, 16b; AC excitation coil, 19: Resistor, 202 AC excitation power supply, 21a,
21b: Amplifier, 22a, 22b: Double-wave rectifier, 23a. Figure 1 Date 1 2el Figure Figure Figure Figure ML Hinoki Vinegar Lambda Figure Flowing 141 Figure Figure 10 Figure 111 12 Figure 15 Figure 17 Figure 16 Figure 18 Fig. 19 #&Ki, lj2 Fig. 29 Fig. 24 Fig. 28 Fig. 21 Fig. Figure 34 Figure 35 Figure 36

Claims (1)

【特許請求の範囲】 １）磁気特性が角形ヒステリシスを持ち保磁力の小さい
材料で閉磁路を形成した鉄心を２個用い、これら鉄心に
巻回した励磁コイルに高抵抗を直列に接続し、前記励磁
コイルに一定電流を流して前記鉄心にそれぞれ交流磁界
を加えておき、前記２個の鉄心のうち一方の鉄心の中心
を通る導体に流れる電流の磁界によって変化するこの鉄
心の磁束と、他方の導体を通してない鉄心の磁束との差
から前記導体に流れる電流を検出することを特徴とする
電流検出方法。 ２）磁気特性が恒透磁率を有する材料で閉磁路を形成し
た鉄心を２個用い、これら鉄心に巻回した励磁コイルに
高抵抗を直列に接続し、前記励磁コイルに一定電流を流
して前記鉄心にそれぞれ交流磁界を加えておき、前記２
個の鉄心のうち一方の鉄心の中心を通る導体に流れる電
流の磁界によって変化するこの鉄心の磁束と、他方の導
体を通してない鉄心の磁束との差から前記導体に流れる
電流を検出することを特徴とする電流検出方法。[Scope of Claims] 1) Two iron cores each having a closed magnetic circuit formed of a material with rectangular hysteresis and low coercive force are used, and a high resistance is connected in series to an excitation coil wound around these iron cores. An alternating current magnetic field is applied to each of the cores by applying a constant current to the excitation coil, and the magnetic flux of this core changes depending on the magnetic field of the current flowing through the conductor passing through the center of one of the two cores, and the magnetic flux of the other core changes. A current detection method comprising detecting the current flowing through the conductor based on the difference between the magnetic flux of an iron core that does not pass through the conductor. 2) Using two iron cores with closed magnetic circuits made of a material with magnetic properties having constant magnetic permeability, a high resistance is connected in series to the excitation coils wound around these iron cores, and a constant current is passed through the excitation coils. An alternating magnetic field is applied to each of the iron cores, and
The current flowing through the conductor is detected from the difference between the magnetic flux of this core, which changes due to the magnetic field of the current flowing through the conductor that passes through the center of one of the individual cores, and the magnetic flux of the other core that does not pass through the conductor. Current detection method.