JP2745452B2 - Split-type zero-phase current transformer for DC - Google Patents
Split-type zero-phase current transformer for DCInfo
- Publication number
- JP2745452B2 JP2745452B2 JP7049318A JP4931895A JP2745452B2 JP 2745452 B2 JP2745452 B2 JP 2745452B2 JP 7049318 A JP7049318 A JP 7049318A JP 4931895 A JP4931895 A JP 4931895A JP 2745452 B2 JP2745452 B2 JP 2745452B2
- Authority
- JP
- Japan
- Prior art keywords
- current transformer
- current
- core
- phase current
- gap
- 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 - Fee Related
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
- G01R15/186—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using current transformers with a core consisting of two or more parts, e.g. clamp-on type
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は比較的大きな電流を流す
電路の電流値を測定するクランプメータに関し、特に携
帯に適した構造を持つ直流用分割型零相変流器に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp meter for measuring a current value of an electric circuit through which a relatively large current flows, and more particularly to a DC-divided zero-phase current transformer having a structure suitable for carrying.
【０００２】[0002]
【従来の技術】図４に従来のクランプメータの構造例を
示す。円環状の二つのコア４１、４２は、それぞれ４１
ａ，４１ｂ，及び４２ａ，４２ｂの接合点で分割でき、
該二つのコアには電線４３をそれぞれ巻回し、両捲線は
図示のように直列に接続し、接続点をＡ点とし、電線４
３の両端はそれぞれ抵抗Ｒ１，Ｒ２を介して発振器４４
の一端に接続され、該発振器４４の他端をＢ点とする構
成であり、前記Ａ点とＢ点とは短絡片によってショート
される。抵抗Ｒ１，Ｒ２の両端部、Ｄ、Ｃ端子間電圧が
本クランプメータの出力となる。2. Description of the Related Art FIG. 4 shows a structural example of a conventional clamp meter. Each of the two annular cores 41 and 42 is 41
a, 41b and 42a, 42b,
An electric wire 43 is wound around each of the two cores, and both windings are connected in series as shown in FIG.
3 are connected to the oscillator 44 via resistors R 1 and R 2 , respectively.
And the other end of the oscillator 44 is set as a point B, and the points A and B are short-circuited by a shorting piece. The voltage between both ends of the resistors R 1 and R 2 and the terminals D and C is the output of the present clamp meter.
【０００３】図５（ａ），（ｂ）は、それぞれ、前記コ
ア部の正面図と、該正面図におけるＡ１−Ａ１断面図で
ある。円環状の二つのコア４１、４２は同心軸上で並列
に配置された上で、磁気的遮蔽材で形成される外側シー
ルド４５、内側シールド４６、そして側面シールド４７
によって磁気的に遮蔽されている。FIGS. 5A and 5B are a front view of the core portion and a cross-sectional view taken along line A1-A1 in the front view, respectively. The two annular cores 41 and 42 are arranged in parallel on a concentric axis, and furthermore, an outer shield 45, an inner shield 46, and a side shield 47 formed of a magnetic shielding material.
Magnetically shielded by
【０００４】このような構造をもったクランプメータの
円環内に、接合点４１ａ，４１ｂ，及び４２ａ，４２ｂ
を一旦開いて被測定電線１を配置したのち、再び閉じて
該電線１に電流ＩＤＣを流した場合、発振器４４の発生
電圧をＥ，発振周波数をｆとすると、出力端子Ｃ，Ｄ間
に現れる出力電圧は電流ＩＤＣに比例するｆＨｚの交流
電庄となる。この出力電圧を読み取って所定の換算を行
うことによって１次電流ＩＤＣを測定することができ
る。In the ring of the clamp meter having such a structure, joint points 41a, 41b and 42a, 42b are provided.
After placing the measured wire 1 once opened, when a current flows I DC to the power line 1 is closed again, the generated voltage of the oscillator 44 E, the oscillation frequency when it is f, the output terminal C, and between D the output voltage is AC Densho of fHz proportional to the current I DC appearing. By performing a predetermined conversion to read the output voltage can be measured primary current I DC.
【０００５】図６は、前記とは別の従来の装置の例であ
る。この装置では円環状の一つのコア６１は６１ａ，６
１ｂの接合点で分割でき、該コアには電線６２を巻回
し、電線６２の両端は抵抗Ｒ１、発振器６３と直列に接
続される。抵抗Ｒ１の両端の電圧が本クランプメータの
出力となる。FIG. 6 shows another example of the conventional apparatus. In this device, one annular core 61 has 61a, 6
An electric wire 62 is wound around the core, and both ends of the electric wire 62 are connected in series with a resistor R 1 and an oscillator 63. Voltage across the resistor R 1 is an output of the clamp meter.
【０００６】このような構造をもったクランプメータの
円環内に被測定電線１を配置し、該電線１に電流ＩＤＣ
を流した場合、発振器６３の発生交流電圧によって与え
られる励磁電流のプラス側のピーク値とマイナス側のピ
ーク値の大きさの差を検出する。このような原理の閉磁
路の周囲を磁気性材でシールドして直流零相変流器とし
て使用している。[0006] The electric wire 1 to be measured is arranged in the ring of the clamp meter having such a structure, and the electric current I DC
Is supplied, the difference between the positive peak value and the negative peak value of the exciting current given by the AC voltage generated by the oscillator 63 is detected. The periphery of the closed magnetic circuit of such a principle is shielded with a magnetic material and used as a DC zero-phase current transformer.
【０００７】[0007]
【発明が解決しようとする課題】前記した二つの従来の
装置のうち、前者のものでは、被測定電線を挿入時に分
割部を開き、挿入後閉じる際に、分割変流器を２個用い
ている関係上、各々の開閉後の変流器の特性に相互の差
異が生じやすく、一度開くと次の測定時に誤差が大きく
なる傾向がある。また、後者のものでは、変流器は１個
ではあるが、変流器の分割面を一度開き、次に閉じた場
合、分割面の磁気抵抗の変化によって励磁電流が変化
し、性能面に影響を与える。In the former two of the above-mentioned conventional devices, the split part is opened when the electric wire to be measured is inserted, and when the electric wire is closed after the insertion, two split current transformers are used. Because of this, the characteristics of the current transformers after opening and closing tend to differ from each other, and once opened, the error tends to increase during the next measurement. In the latter case, although there is only one current transformer, when the dividing surface of the current transformer is opened once and then closed, the exciting current changes due to the change in the magnetic resistance of the dividing surface, and the performance is reduced. Affect.
【０００８】さらに、両者ともに、発振器を必要とし、
該発振器は安定した周波数をもったものでなくてはなら
ず、回路が複雑となるものであった。Further, both require an oscillator,
The oscillator had to have a stable frequency, and the circuit was complicated.
【０００９】また、変流器の励磁に交流電圧を印加する
ため、変流器の１次側に直流零相電圧が流れると１次側
に交流電圧が誘起される。そのために微小電流で制御を
行っている制御回路に使用する場合には問題があった。Further, since an AC voltage is applied to the excitation of the current transformer, when a DC zero-phase voltage flows through the primary side of the current transformer, an AC voltage is induced on the primary side. For this reason, there is a problem when used in a control circuit that performs control with a very small current.
【００１０】さらに、被測定直流電流に脈流が流れてい
ると、変流器の２次側に出力となって現れ、これが検出
回路に入力して特性誤差となる。本発明は、以上述べた
ような欠点を有しない直流用分割型零相変流器を提供す
ることを目的としている。Further, if a pulsating current flows in the DC current to be measured, it appears as an output on the secondary side of the current transformer, which is input to the detection circuit and causes a characteristic error. An object of the present invention is to provide a split-type zero-phase current transformer for direct current which does not have the above-mentioned disadvantages.
【００１１】[0011]
【課題を解決するための手段】上記の課題は本発明によ
れば、各コアの中間にそれぞれホール素子配置のための
ギャップを設け、両者を対向接続すると円環状となり閉
じた磁気回路が形成される一対のコアと、前記ギャップ
内にそれぞれ配置されるホール素子と、前記一対のコア
のそれぞれの内周、外周および側面を所定の隔離寸法を
有しつつ囲繞する磁気シールド部材と、残留電流に起因
する漏れ磁束による前記各ホール素子の出力を同じよう
にするための可変抵抗器とからなる直流用分割型零相変
流器において、前記所定の隔離寸法は、前記ギャップ寸
法より大であり、前記各ギャップに配置されたホール素
子出力は並列に接続し、残留電流に起因する漏れ磁束に
よる前記各ホール素子の出力を同じようにするための前
記可変抵抗器は、各ホール素子の中の１個或は双方に設
けることで解決することができる。According to the present invention, there is provided according to the present invention, a gap for arranging a Hall element is provided in the middle of each core, and when both are connected to face each other, an annular and closed magnetic circuit is formed. A pair of cores, a Hall element respectively disposed in the gap, a magnetic shield member surrounding the inner circumference, outer circumference and side surfaces of each of the pair of cores while having a predetermined separation dimension, and a residual current. In a direct current split type zero-phase current transformer including a variable resistor for equalizing the output of each Hall element due to leakage magnetic flux, the predetermined isolation dimension is larger than the gap dimension, The output of the Hall element arranged in each of the gaps is connected in parallel, and the variable resistor for equalizing the output of each of the Hall elements due to the leakage magnetic flux caused by the residual current, It can be solved by providing to one or both of the inside of the Hall element.
【００１２】[0012]
【作用】ホール素子を配置するためコアに設けたギャッ
プの位置は、一対のコアの開閉のための分割箇所では異
なるところに設けてあるので、該ギャップを正確に維持
することができる。従って特性が安定する。The position of the gap provided in the core for disposing the Hall element is provided at a different position in the divided portion for opening and closing the pair of cores, so that the gap can be accurately maintained. Therefore, the characteristics are stabilized.
【００１３】零相変流器は、１次電流からの漏れ磁束に
よって特性の良否が左右される。１次電流が流れる電線
を挿入するためには、閉じられた磁気回路を一時的に開
かなくてはならない。そのための開閉用分割箇所は開閉
ごとに磁気的結合状態が微妙に変化するが、磁束検出用
のホール素子を配置する位置は分割箇所から離れるほ
ど、開閉の影響を受けにくくなる。よって、２箇所の開
閉用分割箇所の中間点付近にギャップを設けて、ここに
ホール素子を挿入配置するようにし、しかも、コアを囲
繞する磁気シールドは、ホール素子を挿入するギャップ
の寸法よりも、コア、シールド間寸法を大として隔離し
ているので、零相電流検出用磁気回路に悪い影響を与え
ない。The quality of the zero-phase current transformer depends on the leakage flux from the primary current. In order to insert a wire through which a primary current flows, a closed magnetic circuit must be temporarily opened. For this purpose, the magnetic coupling state of the opening / closing divided portion slightly changes every time the opening / closing is performed. However, as the position of the Hall element for magnetic flux detection becomes farther from the divided portion, the influence of the opening / closing becomes less. Therefore, a gap is provided near the middle point between the two opening / closing divisions, and the Hall element is inserted and arranged here. Further, the magnetic shield surrounding the core is larger than the dimension of the gap into which the Hall element is inserted. Since the size between the core and the shield is large, the magnetic circuit for detecting zero-phase current is not adversely affected.
【００１４】さらに前記のようにホール素子の配置位置
は開閉用分割箇所の中間点付近であるので、この部分を
遮蔽する磁気シールド部においても分割のための空隙が
ない。従って充分な磁気遮蔽効果が期待できる。Further, as described above, the position of the Hall element is near the midpoint of the opening / closing division, so that there is no space for division even in the magnetic shield portion for shielding this part. Therefore, a sufficient magnetic shielding effect can be expected.
【００１５】ホール素子出力調整用の可変抵抗器は、出
力を並列接続される複数のホール素子相互の感度、組
立、シールド効果の微小な差異を漏れ磁束レベルで調整
可能であるため、組立、調整することによって残留特性
が良好となる。The variable resistor for adjusting the output of the Hall element is capable of adjusting a small difference in sensitivity, assembly, and shielding effect among a plurality of Hall elements connected in parallel at the leakage magnetic flux level. By doing so, the residual characteristics are improved.
【００１６】[0016]
【実施例】図１から図３に本発明の実施例を示した。図
１は要部の正面を説明的な断面としたもので、１１はコ
アであり、円環形状を２分割した形となっている。即
ち、円環形状の上下２箇所には装置開閉用として分割箇
所１１ａ，１１ｂを設ける。そして、前記のように分割
した一対のコアのそれぞれの中間に後述のホール素子挿
入用として空隙１５，１６を設ける。1 to 3 show an embodiment of the present invention. FIG. 1 is an explanatory sectional view of the front of the main part. Reference numeral 11 denotes a core, which is formed by dividing an annular shape into two parts. That is, divided portions 11a and 11b are provided at upper and lower portions of the annular shape for opening and closing the device. Then, gaps 15 and 16 are provided in the middle of each of the pair of cores divided as described above for inserting a Hall element described later.
【００１７】１２は外側シールドであり、磁気遮蔽材で
形成され、前記円環形状のコア１１の外周側を遮蔽する
が、コア１１同様、装置開閉用として分割箇所１２ａ，
１２ｂを上下２か所に備える。１３は内側シールドであ
り、磁気遮蔽材で形成され、前記円環形状のコア１１の
内周側を遮蔽するが、コア１１同様、装置開閉用として
分割箇所１３ａ，１３ｂを上下２か所に備える。Numeral 12 denotes an outer shield, which is formed of a magnetic shielding material and shields the outer peripheral side of the annular core 11.
12b is provided in two places, upper and lower. Reference numeral 13 denotes an inner shield, which is formed of a magnetic shielding material and shields the inner peripheral side of the annular core 11, but like the core 11, divided portions 13a and 13b are provided at two upper and lower locations for opening and closing the device. .
【００１８】図２は前記正面図の説明的な側面断面図で
あり、１４は側面シールドであり、磁気遮蔽材で形成さ
れ、前記円環形状のコア１１の側面側を遮蔽するが、コ
ア１１同様、装置開閉用として、図示しない分割箇所を
上下２か所に備える。FIG. 2 is an explanatory side sectional view of the front view. Reference numeral 14 denotes a side shield, which is formed of a magnetic shielding material and shields the side surface of the annular core 11. Similarly, for the opening and closing of the device, two not-shown divisions are provided at upper and lower positions.
【００１９】このようにコア１１は周囲を各シールド部
材により磁気的に遮蔽されるが、各シールドとコア１１
間には、それぞれ所定の空隙を形成する。即ち、ｔ２は
コア１１の側面と側面シールド１４の内面までの空隙の
大きさであり、ｔ３は、コア１１の外周面と外側シール
ド１２の内面までの空隙の大きさであり、ｔ４はコア１
１の内周面と内側シールド１３の内面までの空隙の大き
さである。また、ｔ１は前記ホール素子挿入用として形
成した、コア１１の空隙１５，１６の空隙寸法である。
各空隙寸法の関係はｔ１《ｔ２，ｔ１《ｔ３，ｔ１《ｔ
４とする。As described above, the periphery of the core 11 is magnetically shielded by the respective shield members.
Predetermined voids are formed between them. That, t 2 is the magnitude of the gap to the inner surface side and side surface shield 14 of the core 11, t 3 is the size of the gap to the inner surface of the outer peripheral surface and the outer shield 12 of the core 11, t 4 Is core 1
This is the size of the gap between the inner peripheral surface of the inner shield 1 and the inner surface of the inner shield 13. Further, t 1 is formed as a said Hall element inserting a pore size of the voids 15 and 16 of the core 11.
The relationship between the gap sizes is t 1 << t 2 , t 1 << t 3 , t 1 << t
4 is assumed.
【００２０】図３は本発明の直流用分割型零相変流器の
回路図である。同図において、１７は２個のホール素
子、Ｒ１からＲ４までは抵抗、ＶＲは可変抵抗器、１８
は出力端子、Ｂは電源である。FIG. 3 is a circuit diagram of a DC-divided zero-phase current transformer according to the present invention. In the figure, the two Hall elements 17, the resistor R 1 to R 4, VR is a variable resistor, 18
Is an output terminal, and B is a power supply.
【００２１】ホール素子１７は公知のように、半導体セ
ンサとして、直交する電流と磁界の両方に直角の方向に
起電力が発生するホール効果を用いた素子であり、半導
体薄板の長さ方向に電流を流し、これに直角方向に磁界
を加えると、ホール電圧が出力されるものであるから、
電源Ｂの電圧を２個のホール素子１７端子１、３を並列
に接続して印加する。一方、出力側端子２、４にはそれ
ぞれ抵抗Ｒ１、Ｒ２、Ｒ３、Ｒ４を直列に接続した上
で、両ホール素子１７の出力を並列として取り出すよう
に構成している。また、一方のホール素子１７の出力端
子２、４間には前記可変抵抗器ＶＲが接続されている。As is well known, the Hall element 17 is an element using a Hall effect in which an electromotive force is generated in a direction perpendicular to both an orthogonal current and a magnetic field as a semiconductor sensor. When a magnetic field is applied in a direction perpendicular to this, a Hall voltage is output.
The voltage of the power supply B is applied by connecting the two Hall element 17 terminals 1 and 3 in parallel. On the other hand, resistors R 1 , R 2 , R 3 , R 4 are connected in series to the output terminals 2, 4, respectively, and the outputs of both Hall elements 17 are taken out in parallel. The variable resistor VR is connected between the output terminals 2 and 4 of one Hall element 17.
【００２２】このように構成した本発明の分割型零相変
流器の開閉用分割箇所１１ａ，１２ａ，１３ａ、および
１１ｂ，１２ｂ，１３ｂを開いて、被測定電線（図示せ
ず）を挿入し、該電線に電流が流れることによって生じ
る磁界がホール素子１７に加わるので、両ホール素子１
７の端子２、４間には出力を生じ、出力端子１８にて検
出される。Opening / closing divisions 11a, 12a, 13a and 11b, 12b, 13b of the split-type zero-phase current transformer of the present invention thus constructed are opened, and an electric wire to be measured (not shown) is inserted. Since the magnetic field generated by the current flowing through the electric wire is applied to the Hall element 17, both Hall elements 1
7, an output is generated between the terminals 2 and 4 and detected at the output terminal 18.
【００２３】可変抵抗器ＶＲは、漏れ磁束出力調整用と
して機能し、この可変抵抗器ＶＲは２個のホール素子１
７の相互間のバラツキ調整用としてではなく、シール
ド、空隙をも含めた漏れ磁束出力調整用として使用する
ものであり、前記実施例では、一方のホール素子１７の
出力端子２、４間に設けたが、両方のホール素子１７の
出力端子２、４間に設けてもよい。The variable resistor VR functions for adjusting the leakage magnetic flux output, and the variable resistor VR includes two Hall elements 1.
7 is used not for adjusting the variation between the elements but for adjusting the output of the leakage magnetic flux including the shield and the air gap. In the above-described embodiment, it is provided between the output terminals 2 and 4 of one Hall element 17. However, it may be provided between the output terminals 2 and 4 of both Hall elements 17.
【００２４】図７は、端に円環状コアの中間に２個のホ
ール素子を配置しただけの従来の装置と、本発明の装置
を使用したものとの残留電流特性を比較した図である。
１次電流は直流１００Ａで、縦横の軸は円環内の電線の
配置角度と電流値を示し、点線Ａが前者の従来のもの、
実線Ｂが本発明のものである。この図で理解されるよう
に、Ａ１点において従来最大３７０ｍＡもの値を示した
残留電流が、本発明の実施例では、磁気的遮蔽の効果が
大きく、Ｂ１点において１０ｍＡ程度の残留電流とな
り、大幅に改善されていることがわかる。FIG. 7 is a diagram comparing the residual current characteristics of a conventional device in which two Hall elements are arranged at the end of an annular core and a device using the device of the present invention.
The primary current is 100 A DC, the vertical and horizontal axes show the arrangement angle and current value of the electric wire in the ring, and the dotted line A is the former conventional one.
Solid line B is that of the present invention. As can be understood from this figure, the residual current that previously exhibited a maximum value of 370 mA at point A 1 has a large magnetic shielding effect in the embodiment of the present invention, and has a residual current of about 10 mA at point B 1. It can be seen that it has been greatly improved.
【００２５】[0025]
【発明の効果】以上のように本発明によれば、従来問題
があった開閉を繰り返した時の安定性や、１次電流への
交流電圧の重畳の問題が解消される。また、構造が簡単
なため、装置の製作が容易であり、コアへの捲線も不要
であるので、絶縁が容易で、仕上がり寸法も小型とな
り、携帯時軽量なものが得られる効果がある。As described above, according to the present invention, the conventional problems of stability when switching is repeatedly performed and the problem of superimposition of the AC voltage on the primary current are solved. In addition, since the device has a simple structure, it is easy to manufacture the device, and since there is no need to wind a core, the insulation is easy, the finished size is small, and there is an effect that a lightweight device can be obtained.
【図１】本発明の第１の一実施例の説明的な正面断面図
である。FIG. 1 is an explanatory front sectional view of a first embodiment of the present invention.
【図２】本発明の一実施例の説明的な側面断面図であ
る。FIG. 2 is an explanatory side sectional view of one embodiment of the present invention.
【図３】本発明の一実施例の回路図である。FIG. 3 is a circuit diagram of one embodiment of the present invention.
【図４】従来の装置の説明図である。FIG. 4 is an explanatory view of a conventional device.
【図５】従来の装置の説明図である。FIG. 5 is an explanatory diagram of a conventional device.
【図６】従来の装置の説明図である。FIG. 6 is an explanatory diagram of a conventional device.
【図７】本発明の装置と従来の装置との残留電流特性の
比較図である。FIG. 7 is a comparison diagram of residual current characteristics between the device of the present invention and a conventional device.
１ 被測定電線 １１ コア １１ａ 開閉用分割箇所 １１ｂ 開閉用分割箇所 １２ 外側シールド １２ａ 開閉用分割箇所 １２ｂ 開閉用分割箇所 １３ 内側シールド １３ａ 開閉用分割箇所 １３ｂ 開閉用分割箇所 １４ 側面シールド １５ 空隙 １６ 空隙 １７ ホール素子 １８ 出力端子 ＶＲ 可変抵抗器 Ｂ 電源 DESCRIPTION OF SYMBOLS 1 Electric wire to be measured 11 Core 11a Splitting part for opening and closing 11b Splitting part for opening and closing 12 Outer shield 12a Splitting part for opening and closing 12b Splitting part for opening and closing 13 Inner shield 13a Splitting part for opening and closing 13b Splitting part for opening and closing 14 Side shield 15 Air gap 16 Air gap 17 Hall element 18 Output terminal VR Variable resistor B Power supply
Claims (1)
のためのギャップを設け、両者を対接させると円環状と
なり閉じた磁気回路が形成される一対のコアと、 前記ギャップ内にそれぞれ配置されるホール素子と、 前記一対のコアそれぞれの内周、外周および側面を所定
の隔離寸法を有しつつ囲繞する磁気シールド部材と、 残留電流に起因する漏れ磁束による前記各ホール素子の
出力を同じようにするための可変抵抗器と、 からなる直流用分割型零相変流器において、 前記所定の隔離寸法は、前記ギャップ寸法より大であ
り、前記各ギャップに配置された各ホール素子の出力は
並列に接続し、残留電流に起因する漏れ磁束による前記
各ホール素子の出力を同じようにするための前記可変抵
抗器は、２個のホール素子の１個或は双方に設けられて
いることを特徴とする直流用分割型零相変流器。1. A pair of cores each having a gap in the middle of each core for arranging a Hall element and forming a closed magnetic circuit when they are brought into contact with each other, and arranged in the gap. A magnetic shield member surrounding the inner circumference, outer circumference, and side surfaces of each of the pair of cores with a predetermined separation dimension; And a variable resistor for: a DC-separated zero-phase current transformer, comprising: connected in parallel, the variable resistor for the by the leakage magnetic flux outputs of the Hall elements in the same manner due to the residual current, et al provided in one or both of the two Hall elements A split-type zero-phase current transformer for direct current, characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7049318A JP2745452B2 (en) | 1995-02-15 | 1995-02-15 | Split-type zero-phase current transformer for DC |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7049318A JP2745452B2 (en) | 1995-02-15 | 1995-02-15 | Split-type zero-phase current transformer for DC |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08220141A JPH08220141A (en) | 1996-08-30 |
| JP2745452B2 true JP2745452B2 (en) | 1998-04-28 |
Family
ID=12827627
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7049318A Expired - Fee Related JP2745452B2 (en) | 1995-02-15 | 1995-02-15 | Split-type zero-phase current transformer for DC |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2745452B2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3604276B2 (en) * | 1998-04-13 | 2004-12-22 | 株式会社荏原製作所 | Induction motor and method of detecting wear of bearing thereof |
| JP5245634B2 (en) * | 2008-08-08 | 2013-07-24 | 株式会社豊田自動織機 | Inverter control device |
| EP2682762A1 (en) * | 2012-07-06 | 2014-01-08 | Senis AG | Current transducer for measuring an electrical current, magnetic transducer and current leakage detection system and method |
| JP5533976B2 (en) * | 2012-10-17 | 2014-06-25 | 株式会社豊田自動織機 | Inverter control device |
| JP6306823B2 (en) * | 2013-04-01 | 2018-04-04 | 富士通コンポーネント株式会社 | Current sensor |
| JP6361740B2 (en) * | 2014-11-14 | 2018-07-25 | 株式会社村田製作所 | Current sensor |
| GB2546532B (en) * | 2016-01-22 | 2018-03-21 | Gmc I Prosys Ltd | Measurement device |
| KR101931559B1 (en) * | 2016-12-14 | 2018-12-24 | 한국표준과학연구원 | Multi-clamp current measuring apparatus and curretn measuring system |
| KR102114601B1 (en) * | 2020-02-07 | 2020-06-17 | 이형준 | Dual Toroidal High Frequency CT Sensor Unit for Partial Discharge Measurement of High Power Cables |
| JP2022029714A (en) * | 2020-08-05 | 2022-02-18 | 横河電機株式会社 | Current measurement device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5949547B2 (en) * | 1977-02-02 | 1984-12-03 | 東京電力株式会社 | Transformer for earth resistance measuring device |
| JPS5622964A (en) * | 1979-07-31 | 1981-03-04 | Matsushita Electric Works Ltd | Clamp meter |
| JPH0129584Y2 (en) * | 1986-04-11 | 1989-09-08 | ||
| JPH0545989Y2 (en) * | 1987-01-20 | 1993-11-30 |
-
1995
- 1995-02-15 JP JP7049318A patent/JP2745452B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08220141A (en) | 1996-08-30 |
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