JPH06313781A - Method and device for diagnosing deterioration of insulation of power cable line - Google Patents

Method and device for diagnosing deterioration of insulation of power cable line

Info

Publication number
JPH06313781A
JPH06313781A JP12542793A JP12542793A JPH06313781A JP H06313781 A JPH06313781 A JP H06313781A JP 12542793 A JP12542793 A JP 12542793A JP 12542793 A JP12542793 A JP 12542793A JP H06313781 A JPH06313781 A JP H06313781A
Authority
JP
Japan
Prior art keywords
switch
ground
shield layer
cable
insulation
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.)
Pending
Application number
JP12542793A
Other languages
Japanese (ja)
Inventor
Tadayuki Takeuchi
忠之 竹内
Shoichi Hiyama
章一 檜山
Kazuo Kotani
一夫 小谷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NIPPON TETSUDO KENSETSU KODAN
Hitachi Cable Ltd
Original Assignee
NIPPON TETSUDO KENSETSU KODAN
Hitachi Cable Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NIPPON TETSUDO KENSETSU KODAN, Hitachi Cable Ltd filed Critical NIPPON TETSUDO KENSETSU KODAN
Priority to JP12542793A priority Critical patent/JPH06313781A/en
Publication of JPH06313781A publication Critical patent/JPH06313781A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To realize a method for diagnosing the deterioration of insulation of a long cable line in a hot-line state efficiently and at a low cost. CONSTITUTION:One end of a shielding layer of any one cable or one end of a plurality of shielding layers of a plurality of cables being connected in series (shielding) layers connected in series) is grounded. In either case, a DC component in a charging current of a cable line is measured at the end of the opposite side and thereby deterioration of insulation of the corresponding power cable is diagnosed. By combining a direct-current measuring unit with a DC power source 8, the measurement of a resistance in the length direction of the shielding layer and a sheath insulation resistance is also enabled, and by measuring these resistances in addition, the accuracy of diagnosis can be improved.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明はケーブル線路の絶縁劣化
診断方法および装置、特に長尺ケーブル線路の絶縁劣化
を活線状態で診断する方法および装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for diagnosing insulation deterioration of a cable line, and more particularly to a method and apparatus for diagnosing insulation deterioration of a long cable line in a live state.

【0002】[0002]

【従来の技術】活線状態でケーブル線路の一部に絶縁劣
化が生じたとき、劣化した部分から劣化に対応する信号
が発生し、この信号は通常、ケーブルの充電電流ととも
に金属遮蔽層等の遮蔽層に伝達され、接地線を通じて大
地に流れる。ケーブルの絶縁劣化診断は多くの場合、こ
の接地線を通じて大地に流れる電流を、接地線に直列に
接続した高感度の電流計で測定することにより、行われ
る。この測定を行う際にケーブル線路に直流電圧を重畳
して直流重畳法と、直流電圧を重畳しないで充電電流中
の直流成分を測定する直流成分法とがある。ケーブルの
送電端が集中して設置されている電気室や電源盤では、
各ケーブルの接地線が互いに接近しているから、これら
に測定器を接続して、能率よく絶縁劣化を診断すること
ができる。
2. Description of the Related Art When insulation deterioration occurs in a part of a cable line in a live state, a signal corresponding to the deterioration is generated from the deteriorated part, and this signal is usually generated along with a charging current of the cable such as a metal shielding layer. It is transmitted to the shielding layer and flows to the ground through the ground wire. In many cases, the insulation deterioration diagnosis of a cable is performed by measuring the current flowing through the ground wire to the ground with a high-sensitivity ammeter connected in series to the ground wire. When performing this measurement, there are a direct current superposition method in which a direct current voltage is superimposed on a cable line, and a direct current component method in which a direct current component in a charging current is measured without superimposing a direct current voltage. In the electric room and power panel where the power transmission end of the cable is installed centrally,
Since the ground wires of each cable are close to each other, a measuring instrument can be connected to these to efficiently diagnose insulation deterioration.

【0003】これに対し、鉄道や高速自動車道に沿って
設置されるケーブル線路等、複数のケーブルが直列に接
続されて長い線路を形成している場合には、劣化信号を
取り出すのに利用できる接地線が線路の長さ方向に互い
に隔たっているから、一組の測定器を移動して測定する
か、あるいは接地線のある接続部毎に測定器を設置し
て、テレメータリングを行うかの、いずれかの方法で絶
縁劣化の診断を行うことが必要になる。
On the other hand, when a plurality of cables are connected in series to form a long line, such as a cable line installed along a railway or a highway, it can be used to extract a deteriorated signal. Since the ground lines are separated from each other in the length direction of the line, whether to measure by moving a set of measuring instruments, or to install a measuring instrument for each connection part with a grounding line and perform telemetering It is necessary to diagnose the insulation deterioration by either method.

【0004】[0004]

【発明が解決しようとする課題】しかし、従来のこのよ
うな長尺ケーブル線路の絶縁劣化診断方法には、次のよ
うな欠点がある。前者、すなわち一組の測定器を移動し
て測定する方法では、移動にも測定そのものにも時間が
かかり、能率が悪い。接続部毎に測定器を設置する方法
では、測定器とデータ伝送装置の多数の組合せを用いな
ければならないので、コストが高くなる。
However, the conventional method for diagnosing insulation deterioration of such a long cable line has the following drawbacks. The former method, that is, the method of moving and measuring a set of measuring instruments, requires much time for moving and measuring itself and is inefficient. The method of installing the measuring device for each connection requires a large number of combinations of the measuring device and the data transmission device, which increases the cost.

【0005】それ故、本発明の目的は、能率よく、安い
コストで、長尺ケーブル線路の絶縁劣化を活線で診断す
る方法を、実現することである。
Therefore, it is an object of the present invention to realize a method for diagnosing insulation deterioration of a long cable line on a live line efficiently and at low cost.

【0006】また、本発明の目的は、能率よく、安いコ
ストで、長尺ケーブル線路の絶縁劣化を活線で診断する
ことができる装置を、実現することである。
Another object of the present invention is to realize an apparatus capable of diagnosing insulation deterioration of a long cable line on a live line efficiently and at low cost.

【0007】[0007]

【課題を解決するための手段】本発明では、能率よく、
安いコストで、長尺ケーブル線路の絶縁劣化を活線で診
断する方法を実現するため、何れか一つのケーブルの遮
蔽層の一端を接地するか、あるいは複数のケーブルの、
直列に接続した複数の遮蔽層(便宜上、直列接続遮蔽層
と称する)の一端を接地し、いずれの場合も反対側の端
でケーブル線路の充電電流中の直流成分を測定して、対
応する電力ケーブルの絶縁劣化を診断するように構成し
た。この構成では、直流電流測定器に直流電源を組み合
わせれば、遮蔽層の長さ方向の抵抗やシース絶縁抵抗の
測定も可能となる。従って、診断の精度を高めるため
に、これらも併せて測定することが好ましい。一つまた
は複数の遮蔽層の一端を接地し、また複数の遮蔽層を直
列に接続するための開閉スイッチとしては、電磁開閉器
のB型接点等を利用することが好ましい。
According to the present invention, the
In order to realize a method of diagnosing the insulation deterioration of a long cable line with a live line at a low cost, one end of the shielding layer of any one cable is grounded, or
Ground one end of multiple shield layers connected in series (referred to as series-connected shield layers for convenience), and in each case measure the DC component in the charging current of the cable line at the opposite end to obtain the corresponding power. It was configured to diagnose cable insulation deterioration. With this configuration, if a DC power source is combined with a DC current measuring device, the resistance in the length direction of the shielding layer and the sheath insulation resistance can be measured. Therefore, in order to improve the accuracy of diagnosis, it is preferable to measure these as well. As the opening / closing switch for grounding one end of one or more shielding layers and connecting the plurality of shielding layers in series, it is preferable to use a B-type contact of an electromagnetic switch or the like.

【0008】より具体的には、次のように構成する。す
なわち、 (1) 所要区間についての直流成分の測定 所要区間について直流成分を測定するときには、その区
間を含む複数の遮蔽層を、接続部の両側の遮蔽層の引出
し線(接地線)の間に設けたスイッチ(第二のスイッチ
と称する)により直列に接続して、直列接続遮蔽層を構
成し、一方の端(例えば、負荷側)の接地線を直接接地
し、他端は接地されない(実際的には、コンデンサを介
して接地するのが好ましい)状態として、遮蔽層から接
地線、大地を経てケーブル導体に至る、ケーブル外に形
成される回路(この回路に充電電流が流れる)に含まれ
るように、高感度の直流電流測定器を設置して、直流成
分を測定する。この回路は、高圧母線と大地の間に適当
なコイルと電流測定器を直列に接続することにより形成
できる。直列接続遮蔽層の負荷側の終端の接続部で、接
地線と大地の間に電流測定器を挿入してもよい。一方の
端の接地線を直接接地し、他端は接地されない状態にす
るには、複数の電力ケーブルの複数の遮蔽層の接地線に
それぞれスイッチ(第一のスイッチと称する)を設け
(直列接続遮蔽層の一端の遮蔽層では両端に設ける)、
そのうち一つを閉路する。
More specifically, it is constructed as follows. That is, (1) Measurement of direct current component in required section When measuring direct current component in required section, connect multiple shielding layers including the section between the lead wires (ground lines) of the shielding layers on both sides of the connection part. Connected in series with the provided switch (referred to as the second switch) to form a series connection shield layer, directly ground the ground wire at one end (eg, load side), and not ground the other end (actually). In particular, it is preferably grounded via a capacitor), and is included in the circuit formed outside the cable (charging current flows in this circuit) from the shield layer to the ground wire, the ground, and the cable conductor. As described above, a high-sensitivity DC current measuring device is installed to measure the DC component. This circuit can be formed by connecting a suitable coil and ammeter in series between the high voltage busbar and ground. A current measuring device may be inserted between the ground wire and the ground at the connection at the load-side end of the series connection shield layer. To directly ground one end of the ground wire and leave the other end ungrounded, install a switch (referred to as the first switch) on each of the ground wires of the shield layers of the power cables (serial connection). Provided on both ends of the shield layer at one end of the shield layer),
Close one of them.

【0009】(2) 所定のケーブルの遮蔽層の長さ方向の
電気抵抗の測定 まず、ケーブル線路の一端から所定のケーブルまでの遮
蔽層を、前述の第二のスイッチにより直列に接続し、こ
の直列接続遮蔽層の一端のみを上記第一のスイッチの閉
路により接地し、他端に直流電圧を課電して、直列接続
遮蔽層に流れる直流電流を測定し、この電流の大きさか
ら、直列接続遮蔽層の長さ方向の電気抵抗RN を測定す
る。次に、この直列接続遮蔽層から所定のケーブルの遮
蔽層を除外した直列接続遮蔽層の長さ方向の電気抵抗R
N-1 を測定して、これをRN から差し引くことにより、
所定の区間のケーブルの長さ方向の抵抗値が求められ
る。
(2) Measurement of electric resistance in the lengthwise direction of the shield layer of a predetermined cable First, the shield layer from one end of the cable line to the predetermined cable is connected in series by the above-mentioned second switch. Only one end of the series connection shield layer is grounded by the closed circuit of the first switch, and a DC voltage is applied to the other end, and the DC current flowing through the series connection shield layer is measured. The electrical resistance R N in the length direction of the connection shield layer is measured. Next, the electric resistance R in the length direction of the series-connection shield layer obtained by excluding the shield layer of a predetermined cable from the series-connection shield layer.
By measuring N-1 and subtracting this from R N ,
The resistance value in the length direction of the cable in the predetermined section is obtained.

【0010】抵抗測定しようとするケーブルが、ケーブ
ル線路の端に位置するとき等には、そのケーブルの一端
を、その箇所の第一のスイッチにより接地し、他端に直
流電圧を課電して、流れる直流電流から所定の区間のケ
ーブルの長さ方向の抵抗値を直接求めることもできる。
When the cable whose resistance is to be measured is located at the end of the cable line, one end of the cable is grounded by the first switch at that location, and a DC voltage is applied to the other end. Alternatively, the resistance value in the length direction of the cable in a predetermined section can be directly obtained from the flowing DC current.

【0011】各遮蔽層と大地の間にはコンデンサを介在
させることが好ましい。従って、第一のスイッチの各々
に並列にコンデンサを接続することが好ましい。
It is preferable to interpose a capacitor between each shield layer and the ground. Therefore, it is preferable to connect a capacitor in parallel with each of the first switches.

【0012】(3) 所定のケーブルのシース絶縁抵抗の測
定 所定のケーブルのシース絶縁抵抗は、遮蔽層と大地間の
絶縁状態を示し、導体と遮蔽層の間の絶縁劣化とも関係
があることが多いので、遮蔽層の長さ方向の電気抵抗と
ともに、シース絶縁抵抗も測定することが好ましい。
(3) Measurement of sheath insulation resistance of a given cable The sheath insulation resistance of a given cable indicates the insulation state between the shield layer and the ground, and may be related to the deterioration of insulation between the conductor and the shield layer. Since there are many, it is preferable to measure the sheath insulation resistance as well as the electric resistance in the length direction of the shielding layer.

【0013】所定のケーブルについてシース絶縁抵抗を
測定するには、上と同様、まずケーブル線路の一端から
所定のケーブルまでの遮蔽層を、第二のスイッチにより
直列に接続するが、第一のスイッチの開放により、直列
接続遮蔽層の一端での接地を解放し(大地との間にコン
デンサを接続するのが好ましい)、他端に直流電圧を課
電して、直列接続遮蔽層と大地の間に流れる直流電流か
ら、これらの間の絶縁抵抗を測定する。次に、第二のス
イッチの一つを開放して、この直列接続遮蔽層から所定
のケーブルの遮蔽層を除外した直列接続遮蔽層につい
て、同様の測定を行い、所定のケーブルの遮蔽層を含む
ときの絶縁抵抗と、除外したときの絶縁抵抗から、計算
により所定のケーブルの遮蔽層の絶縁抵抗を求める。単
一のケーブルについても同様に、第一のスイッチの開放
により接地を解放し、直流電圧を課電することにより、
絶縁抵抗を求めることができる。
To measure the sheath insulation resistance for a given cable, first, as in the above, the shield layer from one end of the cable line to the given cable is connected in series by the second switch, but the first switch is used. Between the series connection shield layer and ground by releasing the ground at one end of the series connection shield layer (preferably connecting a capacitor to the ground) and applying a DC voltage to the other end. Insulation resistance between them is measured from the direct current flowing through. Next, one of the second switches is opened, and the same measurement is performed for the serial connection shield layer obtained by excluding the shield layer of the predetermined cable from the shield layer of the serial connection, and the shield layer of the predetermined cable is included. Then, the insulation resistance of the shielding layer of the predetermined cable is calculated from the insulation resistance at this time and the insulation resistance at the time of exclusion. Similarly for a single cable, by releasing the ground by opening the first switch and applying a DC voltage,
Insulation resistance can be calculated.

【0014】また、本発明では、能率よく、安いコスト
で、長尺ケーブル線路の絶縁劣化を活線で診断する装置
を実現するため、絶縁劣化活線診断装置を(i)複数の
電力ケーブルの複数の遮蔽層の一つと大地との間に電源
スイッチを介して接続されるとともに、上記遮蔽層に対
応する導体と大地の間に接続された直流電流測定手段、
(ii)複数の遮蔽層の少なくとも一端にそれぞれ設けら
れた複数の接地スイッチ、(iii) 複数の遮蔽層の間に設
けられた直列接続スイッチを備えるものとし、上記電源
スイッチをオフにするとともに接地スイッチ(ii)の一
つをオンにすることにより、対応する電力ケーブルの絶
縁体に流れる充電電流中の直流成分を測定する回路を形
成し、電源スイッチをオンにするとともに接地スイッチ
(ii)をオフにし、かつ必要に応じて直列接続スイッチ
(iii) のうち所定のスイッチをオンにすることにより、
遮蔽層からシースを介して大地に流れる電流を測定する
回路を形成し、電源スイッチをオンにするとともに接地
スイッチ(ii)の一つをオンにし、かつ必要に応じて直
列接続スイッチ(iii) のうち所定のスイッチをオンにす
ることにより、遮蔽層の抵抗を測定する回路を形成する
ように構成した。
Further, in the present invention, in order to realize a device for diagnosing the insulation deterioration of a long cable line with a hot wire efficiently and at a low cost, an insulation deterioration live wire diagnosing device is provided (i) for a plurality of power cables. Direct current measuring means connected between the conductor corresponding to the shielding layer and the ground while being connected via a power switch between one of the plurality of shielding layers and the ground,
(Ii) A plurality of grounding switches provided on at least one end of each of the plurality of shielding layers, and (iii) a series connection switch provided between the plurality of shielding layers. The power switch is turned off and grounded. By turning on one of the switches (ii), a circuit for measuring the direct current component in the charging current flowing through the insulator of the corresponding power cable is formed, and the power switch is turned on and the ground switch (ii) is turned on. Switch off and, if necessary, series connection switch
By turning on the predetermined switch in (iii),
Form a circuit that measures the current flowing from the shielding layer to the ground through the sheath, turn on the power switch and one of the ground switches (ii), and, if necessary, connect the series connection switch (iii). A circuit for measuring the resistance of the shielding layer was formed by turning on a predetermined switch.

【0015】[0015]

【実施例】以下に実施例を示し、本発明のさらに詳細な
説明とする。 〔実施例1〕本発明のケーブル線路の絶縁劣化の活線診
断方法に用いた回路的構成の一例を図1に示す。図1の
回路構成では、高圧ケーブル母線1にケーブル1a,1
b,1cが順次接続され、ケーブル線路が形成されてお
り、各ケーブルの金属遮蔽層2a,2b,2cには引出
し線2aa,2ab,2ba,2bc,2cb,2cd
が設けられている。ケーブル1aの金属遮蔽層2aの送
電側からの引出し線2aaとケーブル1cの金属遮蔽層
2cの負荷側からの引出し線2cdとは、スイッチ3
a,3dおよびそれと並列のコンデンサ4a,4dを経
て大地に接地されている。金属遮蔽層2aと金属遮蔽層
2bの各負荷側からの引出し線2abと2bcは、スイ
ッチ3b,3cを経て接地されている。一方、金属遮蔽
層2bと金属遮蔽層2cの各送電側からの引出し線2b
aと2cbとは、それぞれコンデンサ4b,4cを経て
大地に接地されており、引出し線2abと2baの間、
引出し線2bcと2cbの間には、スイッチ5bと5c
が設けられている。高圧ケーブル母線1に一端が接続さ
れた閉塞コイル1Sの接地側に測定器6を挿入し、測定
器6はコンピュータ7に接続されている。測定器の反接
地側と引出し線2aaの間には、直流電源8がスイッチ
9を介して接続されている。この回路構成は、各スイッ
チの開閉の状態に応じ、以下のように動作する。
EXAMPLES Examples will be shown below for further detailed explanation of the present invention. [Embodiment 1] FIG. 1 shows an example of a circuit configuration used in a method of diagnosing live deterioration of cable line insulation according to the present invention. In the circuit configuration shown in FIG. 1, the high voltage cable bus bar 1 has cables 1a, 1
b and 1c are sequentially connected to form a cable line, and lead wires 2aa, 2ab, 2ba, 2bc, 2cb and 2cd are provided on the metal shielding layers 2a, 2b and 2c of the respective cables.
Is provided. The lead wire 2aa from the power transmission side of the metal shield layer 2a of the cable 1a and the lead wire 2cd from the load side of the metal shield layer 2c of the cable 1c are the switch 3
a, 3d and capacitors 4a, 4d in parallel therewith, and are grounded to the ground. Lead lines 2ab and 2bc from the respective load sides of the metal shield layer 2a and the metal shield layer 2b are grounded via switches 3b and 3c. On the other hand, the lead wire 2b from each power transmission side of the metal shield layer 2b and the metal shield layer 2c.
a and 2cb are grounded to the ground via capacitors 4b and 4c, respectively, and between the lead wires 2ab and 2ba,
Switches 5b and 5c are provided between the lead wires 2bc and 2cb.
Is provided. The measuring device 6 is inserted into the ground side of the closed coil 1S whose one end is connected to the high voltage cable bus 1. The measuring device 6 is connected to the computer 7. A DC power supply 8 is connected via a switch 9 between the non-grounded side of the measuring instrument and the lead wire 2aa. This circuit configuration operates as follows according to the open / closed state of each switch.

【0016】(1) 直流成分の測定 図2(A)に示すように、スイッチ3bを閉じ、スイッ
チ3a,3c,3d,5b,5c,9を開いた状態とし
て、測定器6で直流成分を測定すると、ケーブル1aの
充電電流中の直流成分が測定される。何故なら、スイッ
チ3bを閉じ、スイッチ5bを開くことにより、ケーブ
ル1aの遮蔽層2aはケーブル1bの遮蔽層2bと切り
離され、またスイッチ3aを開くことにより、遮蔽層2
aの送電側(引出し線2aa)と大地の間にはコンデン
サ4aが介在し、負荷側(引出し線2ab)のみがスイ
ッチ3bをへて直接接地される。この結果、遮蔽層2
a、引出し線2ab、スイッチ3b、大地、測定器6、
閉塞コイル1S、高圧母線1、ケーブル1aの高圧導体
に至る閉回路が形成されるから、ケーブル1aに生じた
絶縁劣化の信号は、微弱な直流電流として測定器6で測
定される。
(1) Measurement of DC component As shown in FIG. 2A, the switch 3b is closed and the switches 3a, 3c, 3d, 5b, 5c and 9 are opened, and the DC component is measured by the measuring instrument 6. When measured, the DC component in the charging current of the cable 1a is measured. Because the shield layer 2a of the cable 1a is separated from the shield layer 2b of the cable 1b by closing the switch 3b and the switch 5b, and the shield layer 2 is opened by opening the switch 3a.
A capacitor 4a is interposed between the power transmission side of a (lead wire 2aa) and the ground, and only the load side (lead wire 2ab) is directly grounded through the switch 3b. As a result, the shielding layer 2
a, lead wire 2ab, switch 3b, ground, measuring instrument 6,
Since a closed circuit is formed to reach the closed coil 1S, the high-voltage busbar 1, and the high-voltage conductor of the cable 1a, the signal of insulation deterioration occurring in the cable 1a is measured by the measuring device 6 as a weak DC current.

【0017】また、図2(B)に示すように、スイッチ
3cを閉じ、スイッチ3a,3b,3d,5b,5c,
9を開いた状態で、測定器6で直流成分を測定すると、
ケーブル1bの充電電流中の直流成分が測定される。何
故なら、スイッチ3cを閉じ、スイッチ5cを開くこと
により、ケーブル1bの遮蔽層2bはケーブル1cの遮
蔽層2cと切り離され、またスイッチ3b,5bを開く
ことにより、遮蔽層2aの送電側(引出し線2aa)と
大地の間にはコンデンサ4bが介在し、負荷側(引出し
線2bc)のみがスイッチ3cを経て直接接地される。
ケーブル1bの絶縁劣化の信号は、遮蔽層2b、引出し
線2bc、スイッチ3c、大地を経て、微弱な直流電流
として測定器6で測定される。
As shown in FIG. 2B, the switch 3c is closed and the switches 3a, 3b, 3d, 5b, 5c,
When the direct current component is measured with the measuring instrument 6 with 9 open,
The DC component in the charging current of the cable 1b is measured. Because, by closing the switch 3c and opening the switch 5c, the shield layer 2b of the cable 1b is separated from the shield layer 2c of the cable 1c, and by opening the switches 3b and 5b, the power transmission side (drawer) of the shield layer 2a. The capacitor 4b is interposed between the wire 2aa) and the ground, and only the load side (lead wire 2bc) is directly grounded via the switch 3c.
The signal of the insulation deterioration of the cable 1b is measured by the measuring device 6 as a weak DC current through the shield layer 2b, the lead wire 2bc, the switch 3c, and the ground.

【0018】図1でスイッチ3dを閉じ、スイッチ3
a,3b,3c,5c,9を開き、測定器6で直流成分
を測定すれば、ケーブル1cに起因する直流成分が測定
される。
The switch 3d is closed in FIG.
When a, 3b, 3c, 5c and 9 are opened and the direct current component is measured by the measuring device 6, the direct current component due to the cable 1c is measured.

【0019】(2) シース絶縁抵抗の測定 図3(A)に示すように、スイッチ9を閉じ、スイッチ
3a,3b,5bを開いて、測定器6で直流成分を測定
すると、直流電源8の直流電圧が測定器6を経て大地と
遮蔽層2aの間に印加されるので、ケーブル1aのシー
ス絶縁抵抗が測定される。この抵抗値はコンピュータ7
に記憶される。次いで、図3(B)に示すように、スイ
ッチ9,5bを閉じ、スイッチ3a,3b,3c,5c
を開いた状態にすると、直流電源8の直流電圧は測定器
6を経て大地と直列接続された遮蔽層2a,2bの間に
印加されるから、ケーブル1aと1bを一体にしたシー
ス絶縁抵抗が測定される。そこで、このケーブル1aと
1bを一体にしたシース絶縁抵抗値と、上述のコンピュ
ータ7に記憶されたケーブル1aのシース絶縁抵抗値か
ら、演算によりケーブル1bのシース絶縁抵抗値が求め
られる。
(2) Measurement of sheath insulation resistance As shown in FIG. 3 (A), when the switch 9 is closed and the switches 3a, 3b and 5b are opened and the DC component is measured by the measuring device 6, the DC power source 8 Since a DC voltage is applied between the ground and the shield layer 2a via the measuring device 6, the sheath insulation resistance of the cable 1a is measured. This resistance is computer 7
Memorized in. Then, as shown in FIG. 3B, the switches 9 and 5b are closed, and the switches 3a, 3b, 3c, and 5c are closed.
Is opened, the DC voltage of the DC power supply 8 is applied between the shield layers 2a and 2b connected in series with the ground through the measuring device 6, so that the sheath insulation resistance in which the cables 1a and 1b are integrated is reduced. To be measured. Therefore, the sheath insulation resistance value of the cable 1b is obtained by calculation from the sheath insulation resistance value of the cables 1a and 1b integrated with each other and the sheath insulation resistance value of the cable 1a stored in the computer 7.

【0020】ケーブル1cのシース絶縁抵抗値も、同様
に演算により求められる。すなわち、図1でスイッチ
9,5b,5cを閉じ、スイッチ3a,3b,3c,3
dを開き、測定器6で直流電流を測定すれば、ケーブル
1a,1b,1cを一体にしたシース絶縁抵抗値が測定
されるから、ケーブル1aと1bを一体にしたシース絶
縁抵抗値を利用して、上と同様にして演算によりケーブ
ル1cのシース絶縁抵抗値が求められる。
The sheath insulation resistance value of the cable 1c can be similarly calculated. That is, in FIG. 1, the switches 9, 5b and 5c are closed and the switches 3a, 3b, 3c and 3 are closed.
When d is opened and the direct current is measured by the measuring device 6, the sheath insulation resistance value of the cables 1a, 1b and 1c integrated is measured. Therefore, the sheath insulation resistance value of the cables 1a and 1b integrated is used. Then, the sheath insulation resistance value of the cable 1c is obtained by the same calculation as above.

【0021】(3) 遮蔽層の長さ方向の電気抵抗の測定 図4(A)に示すように、スイッチ9,3bを閉じ、ス
イッチ3a,5bを開いて、直流成分を測定器6で測定
すると、直流電源8の直流電圧は測定器6を経て、遮蔽
層2aの送電側端P1 と負荷側端P2 間に印加されるの
で、測定器6で測定される直流成分から、遮蔽層2aの
長さ方向の電気抵抗が測定され、コンピュータ7に記憶
される。
(3) Measurement of electric resistance in the length direction of the shielding layer As shown in FIG. 4 (A), the switches 9 and 3b are closed, the switches 3a and 5b are opened, and the DC component is measured by the measuring instrument 6. Then, the DC voltage of the DC power source 8 is applied between the power transmission side end P 1 and the load side end P 2 of the shielding layer 2a via the measuring device 6, so that from the DC component measured by the measuring device 6, the shielding layer The electric resistance in the length direction of 2a is measured and stored in the computer 7.

【0022】図4(B)に示すように、スイッチ9,5
b,3cを閉じ、スイッチ3a,3b,5cを開いて、
直流成分を測定器6で測定すると、直流電源8の直流電
圧は測定器6を経て、互いに直列に接続された遮蔽層2
a,2bの送電側端P1 と負荷側端P4 間に印加される
ので、測定器6で測定される直流電流から、遮蔽層2
a,2bを一体にした長さ方向の電気抵抗が測定され
る。そこで、上述のコンピュータ7に記憶された遮蔽層
2aの長さ方向の電気抵抗値と、遮蔽層2aと2bを一
体にした電気抵抗値から、演算により遮蔽層2bの長さ
方向の電気抵抗値が求められる。
As shown in FIG. 4B, the switches 9 and 5 are
b, 3c closed, switches 3a, 3b, 5c opened,
When the direct current component is measured by the measuring device 6, the direct current voltage of the direct current power source 8 passes through the measuring device 6 and is connected in series to the shielding layer 2
Since it is applied between the power transmission side end P 1 and the load side end P 4 of a and 2b, from the DC current measured by the measuring device 6, the shielding layer 2
The electric resistance in the longitudinal direction in which a and 2b are integrated is measured. Therefore, the electric resistance value in the length direction of the shield layer 2b is calculated by calculation from the electric resistance value in the length direction of the shield layer 2a stored in the computer 7 and the electric resistance value in which the shield layers 2a and 2b are integrated. Is required.

【0023】上述の通り、ケーブル1bの絶縁劣化によ
る充電電流中の直流成分、シース絶縁抵抗値、遮蔽層2
bの長さ方向の電気抵抗値が求められるから、直流成分
によって水トリー等の絶縁体劣化を診断するときに、シ
ース絶縁抵抗値および遮蔽層電気抵抗値によって、シー
スおよび遮蔽層の損傷の状態を知ることができ、これに
より劣化診断の精度を高めることができる。
As described above, the DC component in the charging current due to the insulation deterioration of the cable 1b, the sheath insulation resistance value, the shield layer 2
Since the electric resistance value in the lengthwise direction of b is obtained, the state of damage to the sheath and the shielding layer is determined by the sheath insulation resistance value and the shielding layer electric resistance value when diagnosing the insulator deterioration such as a water tree by the DC component. Therefore, the accuracy of deterioration diagnosis can be improved.

【0024】遮蔽層2bと同様に、遮蔽層2cの長さ方
向の電気抵抗値も求められる。すなわち、図4(C)に
示すように、スイッチ9,5b,5c,3dを閉じ、ス
イッチ3a,3b,3cを開いて、直流電流を測定器6
で測定すると、直流電源8の直流電圧は測定器6を経
て、互いに直列に接続された遮蔽層2a,2b,2cの
送電側端P1 と負荷側端P6 間に印加されるので、測定
器6で測定される直流電流から、遮蔽層2a,2b,2
cを一体にした長さ方向の電気抵抗が測定される。そこ
で、上述のコンピュータ7に記憶された、遮蔽層2aと
2b一体の電気抵抗値と、遮蔽層2a,2b,2cを一
体にした電気抵抗値から、演算により遮蔽層2cの長さ
方向の電気抵抗値が求められる。こうして、ケーブル1
cの区間についても、直流成分、シース絶縁抵抗値、遮
蔽層2cの長さ方向の電気抵抗値の測定により、高い信
頼度で絶縁劣化を判定できる。
Similarly to the shield layer 2b, the electric resistance value in the length direction of the shield layer 2c can be obtained. That is, as shown in FIG. 4C, the switches 9, 5b, 5c, 3d are closed, the switches 3a, 3b, 3c are opened, and the direct current is measured by the measuring device 6
In the measurement, since the DC voltage of the DC power supply 8 is applied between the power transmission side end P 1 and the load side end P 6 of the shield layers 2a, 2b, 2c connected in series with each other through the measuring device 6, From the direct current measured by the instrument 6, the shielding layers 2a, 2b, 2
The electrical resistance in the longitudinal direction in which c is integrated is measured. Therefore, from the electric resistance value of the shield layers 2a and 2b integrated and the electric resistance value of the shield layers 2a, 2b, and 2c stored in the computer 7, the electric power in the lengthwise direction of the shield layer 2c is calculated. The resistance value is required. Thus, cable 1
Also in the section c, the insulation deterioration can be determined with high reliability by measuring the DC component, the sheath insulation resistance value, and the electric resistance value in the length direction of the shielding layer 2c.

【0025】上記実施例では、3区間のケーブルを有す
る送電線路について、活線絶縁劣化診断の方法を示した
が、4区間以上を有する送電線路についても、中間の区
間の遮蔽層の両端に、上記ケーブル1bの場合と同じ構
成の回路を設けることにより、任意の区間についての活
線絶縁劣化診断を行うことができる。
In the above embodiment, the method of live line insulation deterioration diagnosis is shown for the transmission line having the cables of three sections. However, the transmission line having four or more sections is also provided at both ends of the shielding layer in the middle section. By providing a circuit having the same configuration as in the case of the cable 1b, it is possible to perform live line insulation deterioration diagnosis for an arbitrary section.

【0026】〔実施例2〕本発明の絶縁劣化活線診断方
法に用いた回路的構成の他の例を図5に示す。図5の回
路構成において、高圧ケーブル母線1、ケーブル1a,
1b,1c、金属遮蔽層2a,2b,2c、引出し線2
aa,2ab,2ba,2bc,2cb,2cd、スイ
ッチ3a,3d、コンデンサ4a,4d、スイッチ5
b,5cは、実施例1(図1)と同じである。図1と異
なり、スイッチ3bは引出し線2baと大地間、コンデ
ンサ4bは引出し線2abと大地間に、スイッチ3cは
引出し線2cbと大地間、コンデンサ4cは引出し線2
bcと大地間に、接続されている。またコイル1Sの接
地側は、測定器6を挿入せず直接接地され、測定器6は
切換スイッチ51の一方の接点51mを介して、引出し
線2cdと大地に、すなわちスイッチ3d、コンデンサ
4dと並列に接続されている。切換スイッチ51の他方
の接点51vと引出し線2cdの間に、直流電源8がス
イッチ9を介して接続される。測定器6にはコンピュー
タ7が接続されている。この回路構成は、各スイッチの
開閉の状態に応じ、以下のように動作する。
[Embodiment 2] FIG. 5 shows another example of the circuit structure used in the method for diagnosing hot line of insulation deterioration of the present invention. In the circuit configuration of FIG. 5, the high voltage cable bus bar 1, the cable 1a,
1b, 1c, metal shielding layers 2a, 2b, 2c, lead wire 2
aa, 2ab, 2ba, 2bc, 2cb, 2cd, switches 3a, 3d, capacitors 4a, 4d, switch 5
b and 5c are the same as in Example 1 (FIG. 1). Unlike FIG. 1, the switch 3b is between the lead wire 2ba and the ground, the capacitor 4b is between the lead wire 2ab and the ground, the switch 3c is between the lead wire 2cb and the ground, and the capacitor 4c is the lead wire 2.
It is connected between bc and the ground. The ground side of the coil 1S is directly grounded without inserting the measuring device 6, and the measuring device 6 is connected to the ground with the lead wire 2cd via one contact 51m of the changeover switch 51, that is, in parallel with the switch 3d and the capacitor 4d. It is connected to the. The DC power supply 8 is connected via the switch 9 between the other contact 51v of the changeover switch 51 and the lead wire 2cd. A computer 7 is connected to the measuring instrument 6. This circuit configuration operates as follows according to the open / closed state of each switch.

【0027】切換スイッチ51を接点51m側に倒し、
スイッチ5c,3c,3d,9を開いた状態として、測
定器6で直流成分を測定すると、ケーブル1cに起因す
る直流成分が測定される。切換スイッチ51はそのまま
で、スイッチ5cを閉じ、スイッチ3b,3c,3d,
5b,9を開いた状態で、測定器6で直流成分を測定す
ると、ケーブル1bと1cに起因する直流成分が測定さ
れる。ケーブル1cに起因する直流成分とケーブル1b
と1cを一体とした直流成分から、測定器6に接続され
たコンピュータ7での演算により、ケーブル1bに起因
する直流成分が求められる。
Tilt the changeover switch 51 to the contact 51m side,
When the DC component is measured by the measuring device 6 with the switches 5c, 3c, 3d and 9 opened, the DC component due to the cable 1c is measured. The changeover switch 51 is left as it is, the switch 5c is closed, and the switches 3b, 3c, 3d,
When the measuring device 6 measures the direct current component with 5b and 9 open, the direct current component due to the cables 1b and 1c is measured. DC component due to cable 1c and cable 1b
From the direct-current component in which 1 and 1c are integrated, the direct-current component due to the cable 1b is obtained by calculation in the computer 7 connected to the measuring device 6.

【0028】切換スイッチ51を接点51v側に倒し、
スイッチ9を閉じ、スイッチ3d,3c,5cを開い
て、測定器6で直流成分を測定すると、直流電源8の直
流電圧が測定器6を経て大地と遮蔽層2cの間に印加さ
れるので、ケーブル1cのシース絶縁抵抗が測定され、
コンピュータ7に記憶される。次いで、スイッチ9,5
cを閉じ、スイッチ3b,3c,3d,5bを開いた状
態にすると、直流電源8の直流電圧は測定器6を経て大
地と遮蔽層2b,2cの間に印加されるから、ケーブル
1bと1cを一体にしたシース絶縁抵抗が測定される。
ケーブル1cのシース絶縁抵抗と、ケーブル1bと1c
を一体にしたシース絶縁抵抗から、測定器6に接続され
たコンピュータ7での演算により、ケーブル1bのシー
ス絶縁抵抗が求められる。
Tilt the changeover switch 51 to the contact 51v side,
When the switch 9 is closed and the switches 3d, 3c, 5c are opened and the DC component is measured by the measuring device 6, the DC voltage of the DC power source 8 is applied between the ground and the shielding layer 2c via the measuring device 6, The sheath insulation resistance of the cable 1c is measured,
It is stored in the computer 7. Then switch 9,5
When c is closed and the switches 3b, 3c, 3d and 5b are opened, the DC voltage of the DC power supply 8 is applied between the ground and the shield layers 2b and 2c via the measuring device 6, so that the cables 1b and 1c are connected. The insulation resistance of the integrated sheath is measured.
Sheath insulation resistance of cable 1c and cables 1b and 1c
The sheath insulation resistance of the cable 1b can be calculated from the integrated sheath insulation resistance of the cable 1b by the computer 7 connected to the measuring instrument 6.

【0029】切換スイッチ51を接点51v側に倒した
状態で、スイッチ3c,9を閉じ、スイッチ5c,3d
を開いて、直流成分を測定器6で測定すると、直流電源
8の直流電圧は測定器6を経て、遮蔽層2cの送電側端
5 と負荷側端P6 間に印加されるので、測定器6で測
定される直流成分から、遮蔽層2cの長さ方向の電気抵
抗が測定され、コンピュータ7に記憶される。次いで、
スイッチ3b,5c,9を閉じ、スイッチ5b,3dを
開いて、直流成分を測定器6で測定すると、直流電源8
の直流電圧は測定器6を経て、遮蔽層2bの送電側端P
3 と遮蔽層2cの負荷側端P6 間に印加されるので、測
定器6で測定される直流成分から、遮蔽層2bと2cを
一体にした長さ方向の電気抵抗が測定されるから、コン
ピュータ7に記憶された遮蔽層2cの電気抵抗の測定値
を用いて、遮蔽層2bの長さ方向の抵抗が演算により求
められる。以上の如く、ケーブル1bの絶縁劣化による
直流成分、シース絶縁抵抗値、遮蔽層2bの長さ方向の
電気抵抗値が求められるので、ケーブル1bの区間の絶
縁劣化を高い信頼度で判定できる。
With the changeover switch 51 tilted to the contact 51v side, the switches 3c and 9 are closed and the switches 5c and 3d are closed.
And the DC component is measured by the measuring device 6, the DC voltage of the DC power source 8 is applied between the power transmitting side end P 5 and the load side end P 6 of the shielding layer 2c via the measuring device 6, The electrical resistance in the length direction of the shielding layer 2c is measured from the direct current component measured by the device 6, and stored in the computer 7. Then
When the switches 3b, 5c, 9 are closed, the switches 5b, 3d are opened, and the DC component is measured by the measuring device 6, the DC power source 8
Of the DC voltage of the shield layer 2b on the power transmission side end P via the measuring device 6.
Since it is applied between 3 and the load-side end P 6 of the shielding layer 2c, the electric resistance in the lengthwise direction in which the shielding layers 2b and 2c are integrated is measured from the DC component measured by the measuring device 6, The resistance of the shield layer 2b in the longitudinal direction is calculated by using the measured value of the electric resistance of the shield layer 2c stored in the computer 7. As described above, the DC component due to the insulation deterioration of the cable 1b, the sheath insulation resistance value, and the electric resistance value in the length direction of the shielding layer 2b are obtained, so that the insulation deterioration in the section of the cable 1b can be determined with high reliability.

【0030】[0030]

【発明の効果】本発明のケーブル線路の絶縁劣化診断方
法では、何れか一つのケーブルの遮蔽層の一端を接地す
るか、あるいは複数のケーブルの、直列に接続した複数
の遮蔽層(直列接続遮蔽層)の一端を接地し、反対側の
端でケーブル線路の充電電流中の直流成分を測定して、
対応する電力ケーブルの絶縁劣化を診断するように構成
したことにより、長尺ケーブル線路でも、接続部に設置
するごく小数の部品と固定した1個の測定器により、活
線状態で、絶縁劣化の診断を行うことができるので、安
いコストと少ない労力で、長尺ケーブル線路の絶縁劣化
を診断できる。本発明の絶縁劣化診断方法は活線状態で
行うものであるが、誤操作により危険が生ずることがな
いよう、フェイルセイフとなっており、安全が常に確保
される。
According to the method of diagnosing insulation deterioration of a cable line of the present invention, one end of the shield layer of any one cable is grounded, or a plurality of shield layers connected in series (shields connected in series) of a plurality of cables. (Layer) is grounded at one end, and the DC component in the charging current of the cable line is measured at the opposite end,
Since it is configured to diagnose the insulation deterioration of the corresponding power cable, even in the case of long cable lines, there is a small number of parts installed at the connection part and one fixed measuring instrument Since the diagnosis can be performed, it is possible to diagnose the insulation deterioration of the long cable line with a low cost and a small labor. Although the insulation deterioration diagnosing method of the present invention is carried out in a live state, it is fail-safe and always secures safety so that danger does not occur due to erroneous operation.

【0031】本発明の上記構成では、直流電流測定器に
直流電源を組み合わせれば、遮蔽層の長さ方向の抵抗や
シース絶縁抵抗の測定も可能となり、直流成分だけでな
く、遮蔽層の外側のシースの絶縁状態および遮蔽層の損
傷の状態を、併せて判定することができるから、劣化診
断の精度を高めることができる。
In the above configuration of the present invention, by combining a DC current measuring device with a DC power source, it becomes possible to measure the resistance in the lengthwise direction of the shielding layer and the sheath insulation resistance, and not only the DC component but also the outside of the shielding layer can be measured. Since the insulation state of the sheath and the damage state of the shield layer can be determined together, the accuracy of deterioration diagnosis can be improved.

【0032】本発明のケーブル線路の絶縁劣化診断装置
は、活線状態のケーブル線路の絶縁劣化診断を、接続部
に設置するごく小数の部品と固定した1個の測定器で構
成される装置で行うものであるため、長尺ケーブル線路
についても安いコストと少ない労力で絶縁劣化を診断で
きる。本発明の絶縁劣化診断装置は活線状態のケーブル
線路に適用するものであるが、誤操作による危険が生じ
ないよう、フェイルセイフとなっており、安全が常に確
保される。さらに本発明の装置は、直流成分だけでな
く、遮蔽層の外側のシースの絶縁状態および遮蔽層の損
傷の状態を併せて判定するから、劣化診断の精度が高
い。
A cable line insulation deterioration diagnosing device of the present invention is a device constituted by a single measuring instrument for fixing the insulation deterioration diagnosis of a cable line in a live state and a small number of parts to be installed at a connecting portion. Since it is performed, it is possible to diagnose the insulation deterioration of a long cable line with low cost and little labor. The insulation deterioration diagnosing device of the present invention is applied to a cable line in a live state, but is fail-safe so that danger due to erroneous operation does not occur, and safety is always ensured. Further, the apparatus of the present invention determines not only the direct current component but also the insulation state of the sheath outside the shielding layer and the state of damage of the shielding layer, and therefore the accuracy of deterioration diagnosis is high.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明による絶縁劣化の活線診断方法の一実施
例に用いた回路構成の説明図である。
FIG. 1 is an explanatory diagram of a circuit configuration used in one embodiment of a method for diagnosing hot line insulation deterioration according to the present invention.

【図2】(A),(B)は同実施例の動作を示す説明図で
ある。
2A and 2B are explanatory views showing the operation of the embodiment.

【図3】(A),(B)は同実施例の動作を示す説明図で
ある。
3A and 3B are explanatory views showing the operation of the embodiment.

【図4】(A)ないし(C)は同実施例の動作を示す説
明図である。
4A to 4C are explanatory views showing the operation of the embodiment.

【図5】本発明の他の実施例に用いた回路構成の説明図
である。
FIG. 5 is an explanatory diagram of a circuit configuration used in another embodiment of the present invention.

【符号の説明】[Explanation of symbols]

1 高圧ケーブル母線 1a,1b,1c ケーブル 1S 閉塞コイル 2a,2b,2c 金属遮蔽層 2aa,2ab 引出し線 2ba,2bc 引出し線 2cb,2cd 引出し線 3a,3d スイッチ 3b,3c スイッチ 4a,4d コンデンサ 4b,4c コンデンサ 5b,5c スイッチ 6 測定器 7 コンピュータ 8 直流電源 9 スイッチ 51 切換スイッチ 51m,51v 接点 1 High-voltage cable busbar 1a, 1b, 1c Cable 1S Closing coil 2a, 2b, 2c Metal shielding layer 2aa, 2ab Lead wire 2ba, 2bc Lead wire 2cb, 2cd Lead wire 3a, 3d switch 3b, 3c switch 4a, 4d Capacitor 4b, 4c Capacitor 5b, 5c Switch 6 Measuring instrument 7 Computer 8 DC power supply 9 Switch 51 Changeover switch 51m, 51v contact

───────────────────────────────────────────────────── フロントページの続き (72)発明者 小谷 一夫 茨城県日立市日高町5丁目1番1号 日立 電線株式会社パワーシステム研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Otani 5-1-1, Hidaka-cho, Hitachi-shi, Ibaraki Hitachi Power Systems Co., Ltd.

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 複数の電力ケーブルを遮蔽層絶縁型の接
続部を介して接続した電力ケーブル線路の絶縁劣化診断
方法において、 前記複数の電力ケーブルの複数の遮蔽層の少なくとも一
端の引出し線と大地の間に、それぞれ第一のスイッチを
設け、 前記接続部の両側の前記遮蔽層の間に第二のスイッチを
設け、 前記第一のスイッチのうちの一つにより、前記複数の遮
蔽層のうちの一つの一端を接地するか、あるいは前記第
二のスイッチにより前記複数の遮蔽層を直列に接続して
成る直列接続遮蔽層の一端を、前記第一のスイッチのう
ち対応する一つのスイッチにより接地し、 前記一つの遮蔽層または前記直列接続遮蔽層を、前記一
端の接地以外はコンデンサによって大地から浮かせた状
態として、前記一つの遮蔽層または前記直列接続遮蔽層
の前記一端とは反対側の端で、前記電力ケーブル線路の
充電電流中の直流成分を測定し、 前記一つの遮蔽層または前記直列接続遮蔽層を、前記一
端の接地以外はコンデンサによって大地から浮かせた状
態で、前記反対側の端で、前記一つの遮蔽層または前記
直列接続遮蔽層に直流電圧を課電して、前記一つの遮蔽
層または前記直列接続遮蔽層に流れる直流電流に基づい
て、抵抗を測定し、 前記対応する一つのスイッチの開放により前記一端の接
地を解放し、かつ前記一つの遮蔽層または前記直列接続
遮蔽層をコンデンサによって大地から浮かせた状態とし
て、前記反対側の端で、前記一つの遮蔽層または前記直
列接続遮蔽層に直流電圧を課電して、前記一つの遮蔽層
または前記直列接続遮蔽層からシースを介して大地に流
れるシース電流を測定し、 前記直流成分、前記抵抗および前記シース電流に基づい
て、対応する電力ケーブルの絶縁劣化を診断することを
特徴とする、電力ケーブル線路の絶縁劣化診断方法。
1. A method for diagnosing insulation deterioration of a power cable line, wherein a plurality of power cables are connected via a shield layer insulation type connecting portion, wherein a lead wire and a ground wire of at least one end of the plurality of shield layers of the plurality of power cables. Between the, each of the first switch, the second switch between the shielding layer on both sides of the connection portion is provided, one of the first switches, among the plurality of shielding layers One of the first switch is grounded, or one end of a series-connected shield layer formed by connecting the plurality of shield layers in series by the second switch is grounded by a corresponding one of the first switches. Then, the one shielding layer or the series connection shielding layer is in a state where the one shielding layer or the series connection shielding layer is floated from the ground by a capacitor except for grounding at one end thereof. The DC component in the charging current of the power cable line was measured at the end opposite to the one end, and the one shield layer or the series connection shield layer was floated from the ground by a capacitor except for grounding the one end. In this state, a DC voltage is applied to the one shield layer or the series connection shield layer at the opposite end, and a resistance is generated based on a direct current flowing through the one shield layer or the series connection shield layer. At the opposite end by releasing the grounding at one end by opening the corresponding one switch and floating the one shielding layer or the series connection shielding layer from the ground by a capacitor, A DC voltage is applied to the one shield layer or the series connection shield layer to measure a sheath current flowing from the one shield layer or the series connection shield layer to the ground through the sheath. And the DC component, on the basis of the resistance and the sheath current, and wherein the diagnosing an insulation deterioration of the corresponding power cable, insulation degradation diagnosis method of the power cable line.
【請求項2】 複数の電力ケーブルを遮蔽層絶縁型の接
続部を介して接続した電力ケーブル線路の絶縁劣化診断
を行う装置において、 前記複数の電力ケーブルの複数の遮蔽層の一つと大地と
の間に電源スイッチを介して接続されるとともに、前記
一つの遮蔽層に対応する導体と大地の間に接続された直
流電流測定手段と、 前記複数の遮蔽層の少なくとも一端にそれぞれ設けられ
た複数の接地スイッチと、 前記複数の遮蔽層の間に設けられた直列接続スイッチを
備え、 前記電源スイッチをオフにするとともに前記複数の接地
スイッチの一つをオンにすることにより、対応する電力
ケーブルの絶縁体に流れる充電電流中の直流成分を測定
する回路を形成し、 前記電源スイッチをオンにするとともに前記接地スイッ
チをオフにし、かつ必要に応じて前記直列接続スイッチ
のうち所定のスイッチをオンにすることにより、遮蔽層
からシースを介して大地に流れる電流を測定する回路を
形成し、 前記電源スイッチをオンにするとともに前記接地スイッ
チの一つをオンにし、かつ必要に応じて前記直列接続ス
イッチのうち所定のスイッチをオンにすることにより、
遮蔽層の抵抗を測定する回路を形成する構成を備えたこ
とを特徴とする、ケーブル線路の絶縁劣化診断装置。
2. An apparatus for diagnosing insulation deterioration of a power cable line, wherein a plurality of power cables are connected via a shield layer insulation type connection portion, wherein: one of the plurality of shield layers of the plurality of power cables and the ground. Direct current measuring means connected between the conductor corresponding to the one shielding layer and the ground while being connected via a power switch between the plurality of shielding layers, and a plurality of DC current measuring means respectively provided at least at one end of the plurality of shielding layers. A ground switch and a series connection switch provided between the plurality of shielding layers are provided. By turning off the power switch and turning on one of the plurality of ground switches, insulation of a corresponding power cable is provided. A circuit for measuring a direct current component in the charging current flowing through the body is formed, and the power switch is turned on and the ground switch is turned off, and if necessary. A circuit for measuring a current flowing from the shielding layer to the ground through the sheath is formed by turning on a predetermined switch among the series connection switches, and the power switch is turned on and one of the ground switches is turned on. By turning on and turning on a predetermined switch among the series connection switches as necessary,
An insulation deterioration diagnosing device for a cable line, comprising a structure for forming a circuit for measuring the resistance of a shielding layer.
【請求項3】 前記遮蔽層の抵抗を測定する回路を形成
するとき、対応する遮蔽層が少なくとも一端でコンデン
サにより大地から浮かされている構成を有する、請求項
第2項のケーブル線路の絶縁劣化診断装置。
3. A cable line insulation deterioration diagnosis according to claim 2, wherein when forming a circuit for measuring the resistance of said shield layer, the corresponding shield layer is floated from the ground by a capacitor at at least one end. apparatus.
JP12542793A 1993-04-28 1993-04-28 Method and device for diagnosing deterioration of insulation of power cable line Pending JPH06313781A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12542793A JPH06313781A (en) 1993-04-28 1993-04-28 Method and device for diagnosing deterioration of insulation of power cable line

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12542793A JPH06313781A (en) 1993-04-28 1993-04-28 Method and device for diagnosing deterioration of insulation of power cable line

Publications (1)

Publication Number Publication Date
JPH06313781A true JPH06313781A (en) 1994-11-08

Family

ID=14909834

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12542793A Pending JPH06313781A (en) 1993-04-28 1993-04-28 Method and device for diagnosing deterioration of insulation of power cable line

Country Status (1)

Country Link
JP (1) JPH06313781A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997025603A1 (en) * 1996-01-03 1997-07-17 Rosemount Inc. Temperature sensor transmitter with sensor sheath lead

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997025603A1 (en) * 1996-01-03 1997-07-17 Rosemount Inc. Temperature sensor transmitter with sensor sheath lead
US5876122A (en) * 1996-01-03 1999-03-02 Rosemount Inc. Temperature sensor

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