JPS644628B2 - - Google Patents
Info
- Publication number
- JPS644628B2 JPS644628B2 JP55123353A JP12335380A JPS644628B2 JP S644628 B2 JPS644628 B2 JP S644628B2 JP 55123353 A JP55123353 A JP 55123353A JP 12335380 A JP12335380 A JP 12335380A JP S644628 B2 JPS644628 B2 JP S644628B2
- Authority
- JP
- Japan
- Prior art keywords
- cable
- current
- guard ring
- shield
- guard
- 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
Links
- 239000004020 conductor Substances 0.000 claims description 11
- 238000000034 method Methods 0.000 claims description 11
- 238000005259 measurement Methods 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 4
- 238000009434 installation Methods 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 239000000284 extract Substances 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/58—Testing of lines, cables or conductors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Description
【発明の詳細な説明】
本発明は、高圧送電に用いられるケーブルの直
流漏れ電流の測定方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring direct current leakage current in cables used for high voltage power transmission.
高圧送電に用いられる布設前あるいは布設後の
ケーブルの電気特性を調べる試験の中に、直流漏
れ電流の測定がある。 DC leakage current measurement is one of the tests to examine the electrical characteristics of cables used for high-voltage power transmission before or after installation.
従来、工場試験において、ケーブルの直流漏れ
電流を測定するには、第１図に示すように、被測
定ケーブル１の両終端２，３にブツシング４，５
とシールドリング６，７とを取り付け、一方の終
端２において被測定ケーブル１の導体と接続され
た端子８と大地９との間に電源１０を用いて直流
高電圧を印加する一方、被測定ケーブル１の遮蔽
１１と大地９との間に電流検出器１２を挿入し
て、ケーブル導体からケーブル絶縁体を経て遮蔽
に流れ込む漏れ電流を測定するようにしていた。
そして、ブツシング４，５の表面において発生す
る沿面リークが電流検出器Ａに流れ込んで測定誤
差を生むのを防止するために、ガード電極１３，
１４を設けてこれを大地９に接続している。 Conventionally, in order to measure the direct current leakage current of a cable in a factory test, as shown in FIG.
and shield rings 6 and 7 are attached, and a high DC voltage is applied using a power source 10 between a terminal 8 connected to the conductor of the cable under test 1 at one end 2 and the ground 9. A current detector 12 is inserted between the shield 11 of No. 1 and the ground 9 to measure leakage current flowing from the cable conductor through the cable insulator and into the shield.
In order to prevent creepage leakage generated on the surfaces of the bushings 4 and 5 from flowing into the current detector A and causing measurement errors, guard electrodes 13,
14 is provided and connected to the earth 9.
このガード電極はブツシング４，５の中間部外
周に鉛テープ等の金属テープを巻き付けたもの
で、これによつて第２図に示したような等価回路
が形成できる。第２図の各記号は以下のものを示
している。 This guard electrode is made by wrapping a metal tape such as lead tape around the outer periphery of the intermediate portion of the bushings 4 and 5, thereby forming an equivalent circuit as shown in FIG. Each symbol in FIG. 2 indicates the following.
Ｒ；被測定ケーブルの導体と遮蔽との間の絶縁抵
抗
IR；Ｒを流れる電流（直流漏れ電流）
r1；シールドリングとガード電極との間の絶縁抵
抗
i1；r1を流れる電流（沿面放電電流）
r2；ガード電極と大地との間の絶縁抵抗
i2：r2を流れる電流
RA；電流検出器の内部抵抗
IA；電流検出器を通る電流
i3；ガード電極から大地へ流れる電流
この回路において、一般にr2≫RAであるから、
IRがr2を通つて大地に流れ出ることは無い。ま
た、i1がr2を通り測定器に流れ込むことは無い。
故にi1はほぼi3と等しくi2は従つて零となり、沿
面放電電流の電流検出器への侵入が除去され、IR
＝IAとなりケーブル自体の漏れ電流を正確に測定
することができる。R: Insulation resistance between the conductor of the cable under test and the shield I R ; Current flowing through R (DC leakage current) r 1 ; Insulation resistance between the shield ring and guard electrode i 1 ; Current flowing through r 1 ( creeping discharge current) r 2 ; Insulation resistance between guard electrode and ground i 2 : Current flowing through r 2 R A ; Internal resistance I A of the current detector; Current passing through the current detector i 3 ; From guard electrode to ground In this circuit, generally r 2 ≫R A , so
I R does not flow to the earth through r 2 . Moreover, i 1 does not flow into the measuring device through r 2 .
Therefore, i 1 is approximately equal to i 3 and i 2 is therefore zero, the creeping discharge current entering the current detector is eliminated, and I R
= I A , and the leakage current of the cable itself can be measured accurately.
ところが、このような従来の測定方法を実施す
るためには、ブツシングへのガード電極の取り付
け作業に手間と時間を要し、測定時間に制約があ
る場合や、作業が高所作業となる場合にはこれを
省略せざるを得ず、短時間で正確な漏れ電流測定
を行う方法の開発が要求されていた。 However, in order to carry out such conventional measurement methods, it takes time and effort to attach the guard electrode to the bushing, and it is difficult to carry out when there are restrictions on measurement time or when the work involves working at heights. This had to be omitted, and there was a need to develop a method to accurately measure leakage current in a short time.
また、上記の方法ではケーブルの遮蔽と大地間
に電流検出器を挿入するため、布設後の線路にこ
れを実施することが難しく、また、高圧側に電流
検出器を挿入した場合は、この検出器に高電圧が
加わり、測定作業が危険となる難点があつた。 In addition, in the above method, a current detector is inserted between the cable shield and the ground, so it is difficult to implement this on the line after installation, and if a current detector is inserted on the high voltage side, this detection The problem was that high voltage was applied to the instrument, making measurement work dangerous.
本発明は上記のような従来の測定方法の難点を
解決したもので、簡便にかつ正確にしかも布設後
の線路においても実施可能な直流漏れ電流の測定
方法を提供するものである。 The present invention solves the problems of the conventional measuring methods as described above, and provides a method for measuring direct current leakage current that is simple and accurate and can be carried out even on lines after installation.
第３図は本発明の方法の実施例結線図で、被測
定ケーブル１の両終端２，３に設けられたブツシ
ング４，５の先端とシールドリング６，７とを覆
うようにガードリングＡ，Ｂが取り付けられてい
る。そして、このガードリングＡ，Ｂは、被測定
ケーブル１の導体にも遮蔽に対しても絶縁的に保
持され、外部に設けられた直流高圧電流１０とリ
ード線１５および高圧分岐線１６によつて接続さ
れる。さらに、一方の終端３において、ガードリ
ングＢと被測定ケーブル１の導体１７との間を電
流検出器１８を介して電気接続している。 FIG. 3 is a wiring diagram of an embodiment of the method of the present invention, in which guard rings A, B is attached. The guard rings A and B are insulated from both the conductor of the cable to be measured 1 and the shield, and are connected to the externally provided DC high-voltage current 10, lead wire 15, and high-voltage branch wire 16. Connected. Further, at one end 3, the guard ring B and the conductor 17 of the cable to be measured 1 are electrically connected via a current detector 18.
この電流検出器１８の出力は、絶縁性伝送路１
９例えば光フアイバを通じて記録計２０に送られ
る。 The output of this current detector 18 is the insulated transmission line 1
9 is sent to a recorder 20, for example via an optical fiber.
上記ガードリングの内部構造の詳細を第４図お
よび第５図に示した。第１図も含め全図において
同一部分は同一符号で示している。 The details of the internal structure of the guard ring are shown in FIGS. 4 and 5. Identical parts are designated by the same reference numerals in all figures, including FIG. 1.
第４図において、ガードリングＢは、導電性金
属をプレス成形したもので、その中間に同材質の
しきり板２１が溶接等によつて取り付けられてい
る。このしきり板２１中央にはナツト２２が溶接
され、ケーブル導体とブツシング５内で電気接続
された導体引出棒２３の先端のネジ切り加工され
た部分と螺合している。また、ガードリングＢの
下端はブツシング５の表面に密着するよう半導電
ゴムリング２４が取り付けられている。第５図の
ガードリングＡはその内部構造は上述と全く同様
であるからその説明を省略する。なお、ガードリ
ング上端には両ガードリングを電気接続する高圧
分岐線１６が固定されている。 In FIG. 4, the guard ring B is press-molded from conductive metal, and a partition plate 21 made of the same material is attached in the middle by welding or the like. A nut 22 is welded to the center of this diaphragm plate 21, and is screwed into a threaded portion at the tip of a conductor pull-out rod 23 which is electrically connected to the cable conductor within the bushing 5. Further, a semiconductive rubber ring 24 is attached to the lower end of the guard ring B so as to be in close contact with the surface of the bushing 5. The internal structure of the guard ring A shown in FIG. 5 is exactly the same as that described above, so a description thereof will be omitted. Note that a high voltage branch line 16 is fixed to the upper end of the guard ring to electrically connect both guard rings.
さて、第４図のガードリングＢ内には、さらに
電流検出器が収容されているのでその詳細を説明
する。 Now, a current detector is further housed in the guard ring B of FIG. 4, so its details will be explained.
直流高圧電流１０に接続されたリード線１５
は、ガードリングＢに設けられたチユーリツプコ
ンクタト等から成る接続器２５に接続され、渡り
線２６を介してナツト２２に直流高電圧を印加し
ている。この渡り線２６にはその中間に電流検出
部２７が挿入され、渡り線２６に流れる微少な電
流信号を取り出す。この電流信号はアンプ２８で
増幅され、電気−光交換器２９により光信号に変
換され、光フアイバ１９によつて絶縁的にガード
リング外へ導びかれ、記録計２０に記録される。 Lead wire 15 connected to DC high voltage current 10
is connected to a connector 25 formed of a tube connector or the like provided on the guard ring B, and applies a DC high voltage to the nut 22 via a connecting wire 26. A current detection section 27 is inserted in the middle of the crossover wire 26 and extracts a minute current signal flowing through the crossover wire 26. This current signal is amplified by an amplifier 28, converted into an optical signal by an electro-optical exchanger 29, led insulatively to the outside of the guard ring by an optical fiber 19, and recorded on a recorder 20.
即ち、ケーブル導体から絶縁体を通つて遮蔽に
流れる直流漏れ電流は第４図のような電流検出器
によつて正確に検出され記録される。なお、この
検出器は電池等の電源３０により駆動される。 That is, the direct current leakage current flowing from the cable conductor through the insulation to the shield is accurately detected and recorded by a current detector such as that shown in FIG. Note that this detector is driven by a power source 30 such as a battery.
以上説明したシスステムを用いて実施される本
発明の方法においては、電流検出器がガードリン
グ内部に収容され、かつガードリングとケーブル
の導体とが同電位にあるので、ガードリング内部
で放電の生じる余地が無い。しかもガードリング
と大地間およびリード線等と大地間で生じた放電
電流が測定系に流れ込まないため、きわめて高精
度にケーブルの漏れ電流を測定することができ
る。 In the method of the present invention carried out using the system described above, the current detector is housed inside the guard ring, and the guard ring and the cable conductor are at the same potential, so that no discharge occurs inside the guard ring. There's no room. Moreover, since the discharge current generated between the guard ring and the ground and between the lead wire and the ground does not flow into the measurement system, the leakage current of the cable can be measured with extremely high accuracy.
さらに、電流検出器を高圧側に挿入したので、
ケーブルの遮蔽はそのまま接地でき、布設後のケ
ーブルに対してもこの測定を実施することができ
る。そして、例えば３相送電路の各ケーブルの測
定の際は、高圧分岐線の代用として並設された残
りの２本のケーブルの一方を用いることもできる
ので、終端のみを相互に接続することにより、長
尺のケーブルの測定も安全に行なうことができ
る。また、あらかじめ組立てられたガードリング
をケーブル終端の先端に被せるだけで測定準備が
でき、従来のようなガード電極の取り付け作業等
の繁雑な作業を省略することができる。 Furthermore, since I inserted a current detector on the high voltage side,
The cable shield can be grounded as is, and this measurement can also be performed on the cable after installation. For example, when measuring each cable in a three-phase power transmission line, one of the remaining two cables installed in parallel can be used as a substitute for the high-voltage branch line, so by connecting only the ends to each other, , long cables can be measured safely. In addition, measurement preparations can be made simply by placing a pre-assembled guard ring over the end of the cable, and the conventional complicated work of attaching a guard electrode can be omitted.
第１図は従来の漏れ電流測定方法の結線図、第
２図はその等価回路、第３図は本発明の測定方法
の結線図、第４図および第５図はそれぞれ本発明
の方法の実施に好適するガードリング内部構造を
示す縦断面図で、各記号は下記のものを示す。
Ａ，Ｂ……ガードリング、１……被測定ケーブ
ル、２，３……終端、９……大地、１０……直流
高圧電源、１１……遮蔽、１８……電流検出器。
Figure 1 is a wiring diagram of the conventional leakage current measuring method, Figure 2 is its equivalent circuit, Figure 3 is a wiring diagram of the measuring method of the present invention, and Figures 4 and 5 are implementations of the method of the present invention. It is a vertical cross-sectional view showing the internal structure of a guard ring suitable for the following. A, B... Guard ring, 1... Cable to be measured, 2, 3... Termination, 9... Earth, 10... DC high voltage power supply, 11... Shield, 18... Current detector.
Claims (1)
導体と遮蔽体との双方に対して絶縁的に保持され
たガードリングで覆い、一方の前記終端におい
て、前記ガードリングと前記導体とを電流検出器
を介して電気接続し、前記ガードリングと前記遮
蔽との間に直流電圧を印加することを特徴とする
ケーブルの直流漏れ電流測定方法。1. Both ends of the cable to be measured are covered with guard rings that are insulated from both the conductor and the shield of the cable, and at one of the ends, the guard ring and the conductor are connected to a current detector. A method for measuring direct current leakage current of a cable, characterized by applying a direct current voltage between the guard ring and the shield, and applying a direct current voltage between the guard ring and the shield.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55123353A JPS5746169A (en) | 1980-09-05 | 1980-09-05 | Method for measuring leaking dc current from cable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55123353A JPS5746169A (en) | 1980-09-05 | 1980-09-05 | Method for measuring leaking dc current from cable |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5746169A JPS5746169A (en) | 1982-03-16 |
| JPS644628B2 true JPS644628B2 (en) | 1989-01-26 |
Family
ID=14858467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55123353A Granted JPS5746169A (en) | 1980-09-05 | 1980-09-05 | Method for measuring leaking dc current from cable |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5746169A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57179761A (en) * | 1981-04-30 | 1982-11-05 | Dainichi Nippon Cables Ltd | Test method for dc leak current of electric device |
| JPS61187670A (en) * | 1985-02-15 | 1986-08-21 | Showa Electric Wire & Cable Co Ltd | Apparatus for testing insulation of power cable |
| JPH048379Y2 (en) * | 1985-04-19 | 1992-03-03 | ||
| JPS61246671A (en) * | 1985-04-24 | 1986-11-01 | Showa Electric Wire & Cable Co Ltd | Dc leakage current measuring apparatus for power cable |
| JPS61288175A (en) * | 1985-06-14 | 1986-12-18 | Showa Electric Wire & Cable Co Ltd | Measuring instrument for insulation deterioration of electric power cable |
| JPS6399281U (en) * | 1986-12-19 | 1988-06-27 |
-
1980
- 1980-09-05 JP JP55123353A patent/JPS5746169A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5746169A (en) | 1982-03-16 |
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