JPH03251771A - Method for measuring conductor current of power cable - Google Patents
Method for measuring conductor current of power cableInfo
- Publication number
- JPH03251771A JPH03251771A JP2048826A JP4882690A JPH03251771A JP H03251771 A JPH03251771 A JP H03251771A JP 2048826 A JP2048826 A JP 2048826A JP 4882690 A JP4882690 A JP 4882690A JP H03251771 A JPH03251771 A JP H03251771A
- Authority
- JP
- Japan
- Prior art keywords
- current
- power cable
- magnetic field
- cable
- conductor current
- 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.)
- Granted
Links
- 239000004020 conductor Substances 0.000 title claims abstract description 26
- 238000000034 method Methods 0.000 title claims description 12
- 230000003287 optical effect Effects 0.000 abstract description 10
- 239000013307 optical fiber Substances 0.000 abstract description 7
- 230000000694 effects Effects 0.000 abstract description 2
- 238000005259 measurement Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
Landscapes
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、電力ケーブルの主導体に流れる導体電流を測
定するための電力ケーブルの導体電流測定方法に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power cable conductor current measuring method for measuring a conductor current flowing through a main conductor of a power cable.
［従来の技術］
高圧の電力ケーブルを保守監視する上で、ケーブル導体
を流れる導体電流を正確に測定することが重要である。[Prior Art] When maintaining and monitoring high-voltage power cables, it is important to accurately measure the conductor current flowing through the cable conductors.
このため、従来から電力ケーブルに流れる交流電流によ
ってケーブル周囲に発生する交流磁界を二次コイルで検
出し、電流測定を行う所謂ＣＴ （Ｃｕｒｒｅｎｔ Ｔ
ｒａｎｓｆｏｒｍｅｒｌ と称する磁界センサが用いら
れるこ゛とが多い。For this reason, so-called CT (Current T
A magnetic field sensor called a transformer is often used.
［発明が解決しようとする課題］
しかしながら、従来用いられている磁界センサＣＴでは
、検出コイルを電力ケーブルの最外周に配置しているの
で、測定すべき導体電流だけでな（、例えばケーブルシ
ースを流れるシース電流の影響をも受けて正確な導体電
流測定ができないという問題がある。[Problems to be Solved by the Invention] However, in the conventionally used magnetic field sensor CT, the detection coil is placed at the outermost circumference of the power cable. There is a problem in that accurate conductor current measurement cannot be performed due to the influence of the flowing sheath current.
本発明の目的は、シース電流等の影響を除去して、導体
電流のみを正確に測定できる電力ケーブルの導体電流測
定方法を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide a method for measuring conductor current of a power cable, which can eliminate the influence of sheath current and the like and accurately measure only the conductor current.
［課題を解決するための手段］
上述の目的を達成するために、本発明に係る電カケ−プ
ルの導体電流測定方法においては、電力ケーブルの周囲
に発生する磁界を検出する磁界センサにより前記電力ケ
ーブルを流れる電流を測定する場合において、前記電力
ケーブルの絶縁接続部に接続される一方の電力ケーブル
の周囲と、該電力ケーブルのシース線に前記絶縁接続部
において接続する接地線の周囲の２個所にそれぞれ磁界
センサを周設し、これらの出力を差動的に接続すること
により、前記電力ケーブルの導体電流を測定することを
特徴とする。[Means for Solving the Problems] In order to achieve the above-mentioned object, in the method for measuring conductor current of a power cable according to the present invention, the power is measured by a magnetic field sensor that detects a magnetic field generated around the power cable. When measuring the current flowing through a cable, two locations: around one of the power cables connected to the insulated connection part of the power cable, and around the ground wire connected to the sheath wire of the power cable at the insulated connection part. The conductor current of the power cable is measured by disposing a magnetic field sensor around each of the power cables and differentially connecting their outputs.
［作用］
上述の構成を有する電力ケーブルの導体電流測定方法に
よれば、絶縁接続部に接続されるケーブルの周囲で導体
電流とシース電流の和の値を測定し、接地線の周囲でシ
ース電流を測定し、これらの差動出力により導体電流を
求める。[Operation] According to the method for measuring conductor current of a power cable having the above-described configuration, the sum of the conductor current and sheath current is measured around the cable connected to the insulated connection part, and the sheath current is measured around the ground wire. , and find the conductor current using these differential outputs.
［実施例］
本発明に係る方法を図示の実施例に基づいて詳細に説明
する。[Example] The method according to the present invention will be explained in detail based on the illustrated example.
第１図は本発明の方法を実施するための結線図である。FIG. 1 is a wiring diagram for implementing the method of the present invention.
絶縁接続部Ｊで電力ケーブルの導体Ｃ同志が接続され、
ケーブルシースＳ同志は絶縁されており、右端のケーブ
ルシースＳは接地線Ｇを介して地絡されている。このよ
うな絶縁接続部Ｊにおいて、右側の電力ケーブルＣには
ケーブル用磁界センサ１、接地線Ｇには接地線用磁界セ
ンサ２を取り付け、ケーブル用磁界センサｌの出力と接
地線用磁界センサ２の出力とを測定回路３に差動的に接
続する。なお、磁界センサｌ、２はケーブルへの装着前
は分割型となっていて、装着後に円環状としてケーブル
Ｃ１接地線Ｇをそれぞれ周回する。ケーブル用磁界セン
サ１によって得られる導体電流Ｉｃとシース電流Ｉｓの
和を与える測定値と、接地線用磁界センサ２によって得
られるシース電流Ｉｓのみの測定値との差動信号をとる
ことによって、正確な導体電流Ｉｃを求めることができ
る。Conductors C of the power cable are connected at the insulated connection J,
The cable sheaths S are insulated from each other, and the rightmost cable sheath S is grounded via a grounding wire G. In such an insulated connection part J, a cable magnetic field sensor 1 is attached to the power cable C on the right side, a grounding line magnetic field sensor 2 is attached to the grounding line G, and the output of the cable magnetic field sensor l and the grounding line magnetic field sensor 2 are attached. and the output of the measuring circuit 3 are differentially connected to the measuring circuit 3. It should be noted that the magnetic field sensors 1 and 2 are of a split type before being attached to the cable, and after being attached, they each go around the cable C1 grounding wire G in an annular shape. By taking a differential signal between the measurement value giving the sum of the conductor current Ic and sheath current Is obtained by the cable magnetic field sensor 1 and the measurement value of only the sheath current Is obtained by the grounding wire magnetic field sensor 2, accurate The conductor current Ic can be found.
測定回路３では、ケーブル用磁界センサ１と接地線用磁
界センサ２との差動信号を半波整流器３１で半波整流す
ると共に、基準信号生成回路３２ではこの差動信号が負
相に転じた時点の例えば２ｍｓ後から、２ｍｓ間の基準
値が連続する基準信号を重畳して、第３図に示すような
送出信号を生成する。次いで、この送出信号をバッファ
３３を介してパルス幅変調回路３４に入力し、このパル
ス幅変調回路３４では三角波発振器３５で発振する基準
三角波との比較により、ゲートを開閉する等の方法によ
って送出信号のパルス幅変調を行う。更に、この変調信
号を発光素子等の電圧−光度換器変換器３６により光変
換して、光ファイバ４に送信する。なお、このような処
理を行う測定回路３の電源は、別の電源用磁界センサ５
を用いて測定すべき電力ケーブルから供給することがで
きる。In the measurement circuit 3, the differential signal between the cable magnetic field sensor 1 and the ground wire magnetic field sensor 2 is half-wave rectified by the half-wave rectifier 31, and the reference signal generation circuit 32 converts this differential signal into negative phase. For example, from 2 ms after the point in time, a reference signal with consecutive reference values for 2 ms is superimposed to generate a transmission signal as shown in FIG. 3. Next, this transmission signal is input to a pulse width modulation circuit 34 via a buffer 33, and the pulse width modulation circuit 34 converts the transmission signal by opening and closing a gate, etc. by comparing it with a reference triangular wave oscillated by a triangular wave oscillator 35. Performs pulse width modulation. Furthermore, this modulated signal is optically converted by a voltage-light intensity converter 36 such as a light emitting element and transmitted to the optical fiber 4. Note that the power supply for the measurement circuit 3 that performs such processing is connected to a separate power supply magnetic field sensor 5.
can be supplied from the power cable to be measured using
このようにして、光ファイバ４に送出された光信号を、
第４図のブロック回路図に示す構成の光受信機６で受信
し、コンピュータ７やオシロスコープ等の出力装置８で
測定する。即ち、光受信機６では光ファイバ４からの光
信号を受光素子等の光電圧変換器６１で電気信号に変換
する。このパルス幅変調波形はＡ／Ｄ変換器６２で適当
なデジタル信号に変換してＣＰＵ６３で処理し、例えば
Ｒ３２３２Ｃ規格等のインタフェース６４を介してコン
ピュータ７と接続することにより、自動測定、自動制御
等を行うことも可能である。この際に、測定回路３で半
波整流波形に重畳した基準信号は、波高値や時間の基準
として用いることができる。また、パルス幅復調回路６
５で変調波形を復調し、適当なバッファ６６を介して出
力し、出力装置８等に接続して波形の観察、監視を行っ
てもよい。In this way, the optical signal sent to the optical fiber 4 is
The signal is received by an optical receiver 6 having the configuration shown in the block circuit diagram of FIG. 4, and measured by an output device 8 such as a computer 7 or an oscilloscope. That is, in the optical receiver 6, an optical signal from the optical fiber 4 is converted into an electrical signal by an optical voltage converter 61 such as a light receiving element. This pulse width modulation waveform is converted into an appropriate digital signal by an A/D converter 62, processed by a CPU 63, and connected to a computer 7 via an interface 64 such as the R3232C standard for automatic measurement, automatic control, etc. It is also possible to do this. At this time, the reference signal superimposed on the half-wave rectified waveform by the measurement circuit 3 can be used as a reference for the peak value and time. In addition, the pulse width demodulation circuit 6
The modulated waveform may be demodulated in step 5, output via a suitable buffer 66, and connected to an output device 8 or the like for observation and monitoring of the waveform.
また、光ファイバ４を用いて光信号で測定波形を送受し
ているので、高圧ケーブルの測定でも不要な誘導が防止
でき、遠隔測定でも良好な結果を得ることができる。更
に、測定回路３の電源を電源用磁界センサ５により供給
すれば、別途に電源線等を布設する必要もなく、洞道内
に敷設された電力ケーブル等に対して本方法を適用する
際にも好適である。In addition, since the measurement waveform is transmitted and received as an optical signal using the optical fiber 4, unnecessary guidance can be prevented even when measuring a high voltage cable, and good results can be obtained even when measuring remotely. Furthermore, if the power for the measurement circuit 3 is supplied by the power supply magnetic field sensor 5, there is no need to install a separate power line, etc., and this method can also be applied to power cables laid in a tunnel. suitable.
［発明の効果］
以上説明したように本発明に係る電力ケーブルの導体電
流測定方法は、接地線の周囲でシース電流を測定し、こ
の値を電力ケーブルから得られた電流から差動的に除去
しているので正確な導体電流が測定でき、高圧の電力ケ
ーブルの保守監視が正し〈実施できる。[Effects of the Invention] As explained above, the method for measuring conductor current of a power cable according to the present invention measures the sheath current around the grounding wire and differentially removes this value from the current obtained from the power cable. This allows accurate conductor current measurements and accurate maintenance monitoring of high-voltage power cables.
図面は本発明に係る電力ケーブルの導体電流測定方法の
実施例を示し、第１図は本発明の方法を実施するための
結線図、第２図は測定回路のブロック回路図、第３図は
送出波形の説明図、第４図は光受信機のブロック回路図
である。
符号Ｊは絶縁接続部、Ｃはケーブル導体、Ｓはケーブル
シース、Ｇは接地線、１はケーブル用磁界センサ、２は
接地線用磁界センサ、３は測定回路、４は光ファイバ、
５は電源用磁界センサ、６は光受信機、７はコンピュー
タ、８は出力装置である。
第１図The drawings show an embodiment of the method for measuring conductor current of a power cable according to the present invention, FIG. 1 is a wiring diagram for carrying out the method of the present invention, FIG. 2 is a block circuit diagram of the measuring circuit, and FIG. An explanatory diagram of the transmitted waveform, and FIG. 4 is a block circuit diagram of the optical receiver. Symbol J is an insulated connection part, C is a cable conductor, S is a cable sheath, G is a ground wire, 1 is a magnetic field sensor for cables, 2 is a magnetic field sensor for ground wires, 3 is a measurement circuit, 4 is an optical fiber,
5 is a power supply magnetic field sensor, 6 is an optical receiver, 7 is a computer, and 8 is an output device. Figure 1
Claims (1)
センサにより前記電力ケーブルを流れる電流を測定する
場合において、前記電力ケーブルの絶縁接続部に接続さ
れる一方の電力ケーブルの周囲と、該電力ケーブルのシ
ース線に前記絶縁接続部において接続する接地線の周囲
の２個所にそれぞれ磁界センサを周設し、これらの出力
を差動的に接続することにより、前記電力ケーブルの導
体電流を測定することを特徴とする電力ケーブルの導体
電流測定方法。1. When measuring the current flowing through the power cable with a magnetic field sensor that detects the magnetic field generated around the power cable, the area around one of the power cables connected to the insulated connection part of the power cable, and the power cable The conductor current of the power cable is measured by installing magnetic field sensors at two locations around the grounding wire connected to the sheathed wire at the insulated connection portion, and differentially connecting these outputs. A method for measuring conductor current of a power cable, characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2048826A JP2985154B2 (en) | 1990-02-28 | 1990-02-28 | Power cable conductor current measurement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2048826A JP2985154B2 (en) | 1990-02-28 | 1990-02-28 | Power cable conductor current measurement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03251771A true JPH03251771A (en) | 1991-11-11 |
| JP2985154B2 JP2985154B2 (en) | 1999-11-29 |
Family
ID=12814035
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2048826A Expired - Lifetime JP2985154B2 (en) | 1990-02-28 | 1990-02-28 | Power cable conductor current measurement method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2985154B2 (en) |
-
1990
- 1990-02-28 JP JP2048826A patent/JP2985154B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2985154B2 (en) | 1999-11-29 |
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