JP2854822B2 - Cable oil leak detection method - Google Patents
Cable oil leak detection methodInfo
- Publication number
- JP2854822B2 JP2854822B2 JP7210864A JP21086495A JP2854822B2 JP 2854822 B2 JP2854822 B2 JP 2854822B2 JP 7210864 A JP7210864 A JP 7210864A JP 21086495 A JP21086495 A JP 21086495A JP 2854822 B2 JP2854822 B2 JP 2854822B2
- Authority
- JP
- Japan
- Prior art keywords
- cable
- insulating oil
- oil
- amount
- change
- 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 - Lifetime
Links
Landscapes
- Examining Or Testing Airtightness (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は海底ケーブル等に使用さ
れる長距離に亘り架設されたＯＦケーブル等において、
所定のパラメータにより算出したケーブル内の絶縁油の
変化量と、実際に供給した絶縁油の供給量とを比較する
ことにより、漏油を判定するケーブルの漏油検知方法に
関する。BACKGROUND OF THE INVENTION The present invention relates to a long-distance OF cable or the like used for a submarine cable or the like.
The present invention relates to a method of detecting oil leakage in a cable by comparing a change amount of insulating oil in a cable calculated by a predetermined parameter with an actually supplied amount of insulating oil to determine oil leakage.
【０００２】[0002]
【従来の技術】従来、ケーブルには絶縁油を圧入したＯ
Ｆケーブル等が使用されており、圧入した絶縁油の油圧
を一定範囲の値に保つため、ケーブルの一端において絶
縁油を供給したり、回収したりするポンピングプラント
が設置されている（特公昭４８−３３８３３号）。ま
た、海底ケーブルのように長距離に亘り架設されたケー
ブルでは、その両端にポンピングプラントを配置してい
る（実公昭４４−１６８３２号）。2. Description of the Related Art Conventionally, an insulating oil is press-fitted into a cable.
An F cable or the like is used, and a pumping plant for supplying or recovering the insulating oil at one end of the cable is installed in order to keep the hydraulic pressure of the press-fitted insulating oil within a certain range (Japanese Patent Publication No. Sho 48). -33833). In addition, a cable installed over a long distance, such as a submarine cable, has a pumping plant at both ends (Japanese Utility Model Publication No. 44-16832).
【０００３】一般に、ポンピングプラントは、絶縁油が
封入された貯油槽と、絶縁油を送り出す送油ポンプと、
絶縁油の供給及び回収時に夫々開閉するポンプリリーフ
弁及び還流用リリーフ弁とから構成され、これらが絶縁
油供給管により連結されている。このように構成された
ポンピングプラントでは、基本的に以下のような動作を
行う。[0003] In general, a pumping plant includes an oil storage tank filled with insulating oil, an oil feed pump for sending out the insulating oil,
It comprises a pump relief valve and a reflux relief valve that open and close, respectively, when supplying and collecting the insulating oil, and these are connected by an insulating oil supply pipe. The pumping plant configured as described above basically performs the following operation.
【０００４】先ず、ケーブルの油圧が低下して所定値Ｐ
1となると、送油ポンプが作動し、ケーブルに絶縁油が
供給される。これにより、油圧が上昇し、ケーブルの油
圧が所定値Ｐ2（Ｐ2＞Ｐ1）となるまで送油ポンプは絶
縁油の供給を続ける。[0004] First, when the hydraulic pressure of the cable decreases, a predetermined value P
When it becomes 1 , the oil pump operates and the insulating oil is supplied to the cable. As a result, the oil pressure rises and the oil feed pump continues to supply the insulating oil until the oil pressure of the cable reaches a predetermined value P 2 (P 2 > P 1 ).
【０００５】また、ケーブルの油圧が負荷電流の増加等
により上昇して所定値Ｐ3（Ｐ3＞Ｐ2）となると、還流
リリーフ弁が作動し、余分なケーブルの絶縁油を貯油槽
に戻して、油圧の上昇を抑制する。When the hydraulic pressure of the cable rises due to an increase in load current or the like and reaches a predetermined value P 3 (P 3 > P 2 ), the return relief valve is operated to return excess cable insulating oil to the oil storage tank. To suppress the rise in hydraulic pressure.
【０００６】以上のように作動するポンピングプラント
が設置されたケーブルにおいて、漏油が発生すると、そ
の漏油の量によっても検知方法は異なるが、通常、以下
のような方法により、漏油の有無を検知する。即ち、送
油ポンプが頻繁に作動している場合の油圧の回復状況を
調査したり、ケーブルに供給した絶縁油の供給量と、そ
のケーブルと同一の負荷が作用している他のケーブルの
絶縁油の供給量とを比較したり、また貯油槽内の絶縁油
量の低下を測定することにより、漏油を検知する。When a leak occurs in a cable in which a pumping plant that operates as described above is installed, the detection method differs depending on the amount of the leak, but usually, the presence or absence of the leak is determined by the following method. Is detected. In other words, it is necessary to investigate the oil pressure recovery status when the oil pump is frequently operated, and to check the amount of insulating oil supplied to the cable and the insulation of other cables that are under the same load as the cable. Oil leakage is detected by comparing the amount of oil supplied and measuring the decrease in the amount of insulating oil in the oil storage tank.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、上述の
ような漏油の検知方法では以下のような問題がある。即
ち、長距離に亘り架設されたケーブルにおいては、ポン
ピングプラントが設置されていない一方のケーブル端
（以下、「遠端」という）の油圧を上昇させるために
は、送給ポンプは長時間に亘って作動することが必要で
ある。例えば、５０ｋｍのＯＦケーブルでは、遠端にお
ける油圧上昇を確実に行うためには、３時間以上を要す
る。従って、ポンピングプラントにおける送給ポンプの
作動頻度を調査するだけでは、漏油の検知が遅れてしま
う。それに、このようなケーブルでは、貯油槽の下限値
を設定したり、又は全供給油量の上限値を設定すること
により、貯油槽の油量が前記下限値より小さくなった
り、又は全供給油量が前記上限値を超えた場合に警報等
により漏油を検知できるようにしても、ケーブル内の変
化油量が大きいため、その変化油量の全てが貯油槽から
送給されなければ漏油を検知することができず、多いと
きには検知までに約１０キロリットルもの大量の絶縁油
がケーブル外へ流出することとなり、環境破壊を引き起
こす原因となる。However, the method for detecting oil leakage as described above has the following problems. That is, in a cable installed over a long distance, in order to increase the oil pressure at one cable end (hereinafter, referred to as “far end”) where a pumping plant is not installed, the feed pump needs to be operated for a long time. It is necessary to work. For example, with an OF cable of 50 km, it takes three hours or more to reliably increase the hydraulic pressure at the far end. Therefore, simply investigating the operation frequency of the feed pump in the pumping plant will delay detection of oil leakage. In addition, in such a cable, by setting the lower limit value of the oil storage tank or setting the upper limit value of the total supply oil amount, the oil amount of the oil storage tank becomes smaller than the lower limit value, or the total supply oil amount is reduced. Even if oil leakage can be detected by an alarm or the like when the amount exceeds the upper limit, the amount of changed oil in the cable is large, so if all of the changed oil is not sent from the oil storage tank, Cannot be detected, and when the amount is large, a large amount of insulating oil of about 10 kiloliters flows out of the cable before the detection, which causes environmental destruction.
【０００８】また、単位時間当たりの絶縁油の供給量の
みを調査する場合、ケーブルが長距離に亘って架設され
ていると、漏油量が多くなければ漏油の判定が困難であ
る。When investigating only the supply amount of insulating oil per unit time, if the cable is installed over a long distance, it is difficult to determine oil leakage unless the amount of oil leakage is large.
【０００９】更に、時定数はケーブル自体の熱容量と周
囲土壌の熱容量とによって異なるが、地中に埋設された
ケーブルにおいては、通常数時間から１０数時間もの
間、負荷電流の変化による温度変化が生じ、その間送油
ポンプは動き続けるため、送油ポンプの運転頻度又は全
供給油量の値によって漏油の判定をするには長時間を要
する。Further, the time constant varies depending on the heat capacity of the cable itself and the heat capacity of the surrounding soil. In a cable buried underground, a temperature change due to a change in load current usually takes several hours to several tens of hours. During that time, the oil pump continues to operate, so it takes a long time to determine oil leakage based on the operation frequency of the oil pump or the value of the total oil supply amount.
【００１０】本発明はかかる問題点に鑑みてなされたも
のであって、短時間に漏油を検知して早期にケーブルを
改修することができ、漏油の検知までに流出する絶縁油
を低減して、環境破壊を防止することができるケーブル
の漏油検知方法を提供することを目的とする。The present invention has been made in view of such a problem, and can detect a leak of oil in a short time, repair a cable early, and reduce the amount of insulating oil flowing out before the detection of the leak of oil. Accordingly, an object of the present invention is to provide a method for detecting oil leakage of a cable that can prevent environmental destruction.
【００１１】[0011]
【課題を解決するための手段】本発明に係るケーブルの
漏油検知方法は、ケーブルの負荷電流と、ケーブル周囲
の温度変化、ケーブル上の複数カ所における温度データ
の変化、又は光ファイバによる全長の温度分布データか
ら算出されるケーブル自体の表面温度の変化と、ケーブ
ルの内外各部の熱抵抗及び比熱とに基づいてケーブル内
の絶縁油の温度変化を求め、このケーブル内絶縁油の温
度変化と絶縁油の体積膨張係数によってケーブル内の絶
縁油の変化量を算出し、このケーブル内絶縁油の変化量
とケーブルへ供給された絶縁油のケーブル長手方向の油
圧分布を基にケーブルへの絶縁油の供給量を算出する工
程と、この絶縁油の供給量の算出値と実測値とを比較し
て実測値の方が所定量を超えて多い場合に漏油と判定す
る工程とを有することを特徴とする。SUMMARY OF THE INVENTION According to the present invention, there is provided a method for detecting oil leakage in a cable, comprising: a load current of a cable, a change in temperature around the cable, a change in temperature data at a plurality of locations on the cable, or a change in the total length of the optical fiber. The temperature change of the insulating oil in the cable is determined based on the change in the surface temperature of the cable itself calculated from the temperature distribution data, and the thermal resistance and specific heat of each part inside and outside the cable. by the volume expansion coefficient of the oil was calculated change amount of the insulating oil in the cable, the cable oil <br/> pressure distribution in the cable longitudinal direction of the change amount and the insulating oil supplied to the cable of the cable in the insulating oil based A step of calculating the supply amount of insulating oil to, and a step of comparing the calculated value of the supply amount of insulating oil with the actually measured value and determining that the oil is leaking when the actually measured value is larger than a predetermined amount. With And wherein the Rukoto.
【００１２】[0012]
【作用】本発明においては、ケーブルの負荷電流等から
ケーブルの温度変化を求め、このケーブルの温度変化を
基にケーブル内の絶縁油の変化量を求める。そして、こ
の絶縁油の変化量を、ケーブルへの絶縁油の供給油圧を
基に、絶縁油の供給量理論値に換算する。そこで、絶縁
油の供給量の実測値が理論値より所定量を超えて多い場
合に漏油が発生していると判定する。これにより、迅速
に漏油を検知できる。In the present invention, a change in the temperature of the cable is determined from the load current of the cable and the like, and the amount of change in the insulating oil in the cable is determined based on the change in the temperature of the cable. Then, the change amount of the insulating oil is converted into a theoretical value of the supply amount of the insulating oil based on the hydraulic pressure of the insulating oil supplied to the cable. Therefore, when the measured value of the supply amount of the insulating oil is larger than the theoretical value by more than a predetermined amount, it is determined that the oil leakage has occurred. Thereby, oil leakage can be detected quickly.
【００１３】[0013]
【実施例】以下、本発明の実施例について、添付の図面
を参照して具体的に説明する。図１は本発明の実施例に
使用するポンピングプラントを示すブロック図である。
この図１に示すように、ポンピングプラントにおいて
は、絶縁油１２が封入された貯油槽１と、絶縁油を供給
又は回収する油圧調整部２と、絶縁油の流れ方向及び流
量を計測する流量計４とが給油管１０を介して直列に連
結されており、給油管１０の先端にはケーブル７が連結
されている。Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a pumping plant used in an embodiment of the present invention.
As shown in FIG. 1, in a pumping plant, an oil storage tank 1 filled with insulating oil 12, a hydraulic pressure adjusting unit 2 for supplying or recovering insulating oil, and a flow meter for measuring the flow direction and flow rate of the insulating oil 4 are connected in series via an oil supply pipe 10, and a cable 7 is connected to the end of the oil supply pipe 10.
【００１４】また、貯油槽１にはその現存油量を検出し
てこの検出結果をデータ処理制御部６に伝達する油量伝
送器５が設置されており、油圧調整部２と流量計４との
間には給油管１０の油圧を測定する圧力伝送器３が設置
されている。更に、ケーブル７の先端部にはケーブル７
の負荷電流を計測する電流変換器８が接続されており、
ケーブル７の近傍にはその周囲温度、即ちケーブルが大
気中にある場合の大気温度又はケーブルが埋設されてい
る場合におけるそのルート中の大地温度を計測する温度
センサ９が設けられている。そして、この油量伝送器
５、圧力伝送器３、電流変換器８及び温度センサ９はい
ずれもデータ処理制御部６と通信線１１を介して接続さ
れている。なお、油圧調整部２も通信線１１を介してデ
ータ処理制御部６に接続されており、油圧調整部２では
データ処理制御部６により絶縁油の供給及び回収並びに
油圧が制御されている。The oil storage tank 1 is provided with an oil amount transmitter 5 for detecting the existing oil amount and transmitting the detection result to the data processing control unit 6. Between them, a pressure transmitter 3 for measuring the oil pressure of the oil supply pipe 10 is provided. Further, the cable 7 has a cable 7
Current converter 8 for measuring the load current of
In the vicinity of the cable 7, there is provided a temperature sensor 9 for measuring its ambient temperature, that is, the atmospheric temperature when the cable is in the air or the ground temperature in the route when the cable is buried. The oil amount transmitter 5, the pressure transmitter 3, the current converter 8, and the temperature sensor 9 are all connected to the data processing control unit 6 via the communication line 11. The oil pressure adjusting unit 2 is also connected to the data processing control unit 6 via the communication line 11. In the oil pressure adjusting unit 2, the supply and recovery of the insulating oil and the oil pressure are controlled by the data processing control unit 6.
【００１５】次に、以上のように構成されたポンピング
プラントの動作についてデータ処理制御部６の制御動作
と共に説明する。先ず、データ処理制御部６において、
電流変換器８から出力される負荷電流と、温度センサか
ら出力されるケーブル周囲の温度変化と、ケーブル内外
各部の熱抵抗及び比熱とによりケーブル内の絶縁油の平
均温度変化が計算される。また、この平均温度変化と絶
縁油の体積膨張係数によってケーブル７内の絶縁油の変
化量を算出する。なお、ケーブルの周囲温度の代わり
に、ケーブル上の数カ所における温度データ、又は光フ
ァイバ等による全長の温度分布データ等から算出される
ケーブル自体の表面温度を使用することにより、絶縁油
の変化量における計算精度をより一層向上させることが
できる。Next, the operation of the pumping plant configured as described above will be described together with the control operation of the data processing control unit 6. First, in the data processing control unit 6,
A load current output from the current converter 8, and the ambient temperature change cable output from the temperature sensor, the average change in temperature of the insulating oil in the cable is calculated by the heat resistance and the specific heat of the cable inner and outer sections. Further, the amount of change in the insulating oil in the cable 7 is calculated from the average temperature change and the volume expansion coefficient of the insulating oil. By using the surface temperature of the cable itself calculated from the temperature data at several places on the cable or the temperature distribution data of the entire length of the optical fiber, etc., instead of the ambient temperature of the cable, the amount of change in the insulating oil The calculation accuracy can be further improved.
【００１６】そして、データ処理制御部６は、圧力伝送
器３から出力される供給油圧をベースとして、ケーブル
の等価圧縮弾性係数と前記絶縁油の変化量にケーブルの
長手方向の油圧分布による補正を加えて、ケーブルへの
絶縁油の供給量（理論値）を計算する。The data processing control unit 6 corrects the equivalent compression elastic modulus of the cable and the amount of change of the insulating oil based on the hydraulic pressure distribution in the longitudinal direction of the cable based on the supplied hydraulic pressure output from the pressure transmitter 3. In addition, the supply amount (theoretical value) of the insulating oil to the cable is calculated.
【００１７】このようにして算出された絶縁油の供給量
の値と、実際にケーブルに供給された絶縁油量の流量計
４による計測値とがデータ処理制御部６において比較さ
れる。この場合、油量計算及び流量計の誤差並びに誤発
信防止の裕度を考慮しても、流量計４による実測値が算
出した絶縁油量の値より、例えば約２０％以上大きい場
合に、データ処理制御部６は漏油と判定して警報を発信
する。なお、この場合、ケーブルのサイズ、埋設土壌に
おける長さ方向の不均質性及び測定系の誤差等を考慮す
る必要もあり、約２０％をしきい値として、これを超え
た場合を漏油と判定するが、ケーブル設置後のならし運
転における実績により、適正なしきい値を設定する必要
がある。また、データ処理制御部６では想定される漏油
速度も算出する。In the data processing control unit 6, the value of the insulating oil supply amount calculated in this manner is compared with the value of the insulating oil amount actually supplied to the cable measured by the flow meter 4. In this case, even if the oil amount calculation and the error of the flow meter and the margin for preventing erroneous transmission are taken into account, if the measured value by the flow meter 4 is larger than the calculated value of the insulating oil amount by about 20% or more, for example, The processing control unit 6 determines that there is an oil leak and sends an alarm. In this case, it is necessary to consider the cable size, inhomogeneity in the length direction of the buried soil, errors in the measurement system, and the like. Judgment is required, but it is necessary to set an appropriate threshold value based on the results of the running-in operation after the cable installation. The data processing control unit 6 also calculates an assumed oil leak rate.
【００１８】なお、ポンピングプラントにおける給油ポ
ンプが作動して、ケーブルの圧力弾性に応じた絶縁油が
ケーブルに急激に送り込まれると、油圧が急速に上昇す
るため、油圧変化に伴うケーブル内の油量補正計算を適
正に行って漏油判定の誤差を防止する必要がある。When the oil supply pump in the pumping plant is operated and the insulating oil corresponding to the pressure elasticity of the cable is suddenly fed into the cable, the oil pressure rises rapidly. It is necessary to properly perform correction calculation to prevent an error in oil leakage determination.
【００１９】上述のようなケーブルの一端にのみポンピ
ングプラントを設置するのではなく、その両端に図１に
示すポンピングプラントを配置すると、各ポンピングプ
ラントにおいて、上述のように算出された絶縁油の供給
量と実際に計測された供給量とを比較することにより、
漏油の発生位置を特定することができる。これは、ケー
ブル内の絶縁油の圧力降下を、ケーブルの流動抵抗と絶
縁油の流量との積とし、この場合のケーブル両端の油圧
が同一であるとすると、温度及び圧力を考慮した絶縁油
の給油量が、ポンピングプラントから漏油の発生位置ま
での距離と反比例の関係となるからである。If the pumping plant shown in FIG. 1 is arranged at both ends of the cable instead of installing the pumping plant only at one end of the cable as described above, the supply of the insulating oil calculated as described above is performed at each pumping plant. By comparing the amount with the actual measured supply,
It is possible to specify the position where the oil leak has occurred. This is because the pressure drop of the insulating oil in the cable is the product of the flow resistance of the cable and the flow rate of the insulating oil.In this case, if the oil pressure at both ends of the cable is the same, the temperature and pressure of the insulating oil are considered. This is because the amount of refueling is inversely proportional to the distance from the pumping plant to the location where the oil leak occurs.
【００２０】また、絶縁油の供給量を計算することによ
り貯油槽１内に現存している絶縁油１２の量を算出する
ことができるため、この算出された油量と実際に現存し
ている油量とを比較することにより、漏油を判定するこ
とができる。この場合、実際の絶縁油１２の量と算出さ
れた油量との差が大きくなくても漏油を判定することが
できる。例えば、絶縁油量１２の算出値が３０キロリッ
トルである場合、漏油によって、貯油槽１に封入されて
いる絶縁油１２の量が約１キロリットル程度減少すれば
漏油であることを判定することができる。Further, since the amount of the insulating oil 12 existing in the oil storage tank 1 can be calculated by calculating the supply amount of the insulating oil, the calculated oil amount and the actually existing amount are present. Oil leakage can be determined by comparing the amount of oil. In this case, even if the difference between the actual amount of the insulating oil 12 and the calculated oil amount is not large, the oil leakage can be determined. For example, when the calculated value of the insulating oil amount 12 is 30 kiloliters, it is determined that the oil is leaking if the amount of the insulating oil 12 sealed in the oil storage tank 1 decreases by about 1 kiloliter due to oil leakage. can do.
【００２１】なお、本発明は、単心ＯＦケーブル、３心
ＯＦケーブル又はＰＯＦケーブル等のように内部が絶縁
油で満たされているケーブル全てについて適用すること
ができ、またポンピングプラント以外であっても、油槽
方式の給油を採用している給油方法にも適用することが
できる。The present invention can be applied to all cables whose inside is filled with insulating oil, such as a single-core OF cable, a three-core OF cable, a POF cable, and the like. Also, the present invention can be applied to a refueling method employing an oil tank type refueling.
【００２２】[0022]
【発明の効果】以上説明したように、本発明によれば、
所定のパラメータにより算出したケーブルへの絶縁油の
供給量と、実際に供給した絶縁油の供給量とを比較する
ことにより、短時間に漏油を検知することができ、また
ケーブルの両端から給油することにより、漏油の発生位
置を特定して早期にケーブルを改修することができるた
め、漏油の検知までに流出する絶縁油量を低減して、環
境破壊を防止することができる。As described above, according to the present invention,
By comparing the amount of insulating oil supplied to the cable calculated by the predetermined parameters with the amount of insulating oil actually supplied, oil leakage can be detected in a short time, and lubrication can be performed from both ends of the cable. By doing so, it is possible to repair the cable at an early stage by specifying the position where the oil leak has occurred, so that it is possible to reduce the amount of insulating oil that flows out before the oil leak is detected, thereby preventing environmental destruction.
【図１】本発明の実施例に使用するポンピングプラント
を示すブロック図である。FIG. 1 is a block diagram showing a pumping plant used in an embodiment of the present invention.
【符号の説明】 １；貯油槽 ２；油圧調整部 ３；圧力伝送器 ４；流量計 ５；油量伝送器 ６；データ処理制御部 ７；ケーブル ８；電流変換器 ９；温度センサ １０；給油管 １１；通信線 １２；絶縁油[Description of Signs] 1; Oil storage tank 2; Hydraulic pressure adjuster 3; Pressure transmitter 4; Flow meter 5; Oil flow transmitter 6; Pipe 11; communication line 12; insulating oil
───────────────────────────────────────────────────── フロントページの続き (72)発明者 原 敏明 大阪府大阪市北区中之島３丁目３番22号 関西電力株式会社内 (72)発明者 宮藤 龍二 大阪府大阪市北区中之島３丁目３番22号 関西電力株式会社内 (72)発明者 寺島 一希 東京都中央区銀座６丁目15番１号 電源 開発株式会社内 (72)発明者 重年 生雄 東京都江東区木場１丁目５番１号 株式 会社フジクラ内 (72)発明者 中村 良晴 東京都江東区木場１丁目５番１号 株式 会社フジクラ内 (56)参考文献 特開 平２−28529（ＪＰ，Ａ) 特開 平６−335148（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) G01M 3/28 G01M 3/04 G01M 3/26──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiaki Hara 3-3-22 Nakanoshima, Kita-ku, Osaka-shi, Osaka Inside Kansai Electric Power Company (72) Inventor Ryuji Miyafuji 3-3-1 Nakanoshima, Kita-ku, Osaka, Osaka 22 Kansai Electric Power Co., Inc. (72) Inventor Kazuki Terajima 6-15-1, Ginza, Chuo-ku, Tokyo Power Supply Development Co., Ltd. (72) Inventor Ikuo Shigeno 1-5-1 Kiba, Koto-ku, Tokyo No. Fujikura Co., Ltd. (72) Inventor Yoshiharu Nakamura 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (56) References JP-A-2-28529 (JP, A) JP-A-6-335148 ( JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) G01M 3/28 G01M 3/04 G01M 3/26
Claims (3)
温度変化と、ケーブルの内外各部の熱抵抗及び比熱とに
基づいてケーブル内の絶縁油の温度変化を求め、このケ
ーブル内絶縁油の温度変化と絶縁油の体積膨張係数によ
ってケーブル内の絶縁油の変化量を算出し、このケーブ
ル内絶縁油の変化量とケーブルへ供給された絶縁油のケ
ーブル長手方向の油圧分布を基にケーブルへの絶縁油の
供給量を算出する工程と、この絶縁油の供給量の算出値
と実測値とを比較して実測値の方が所定量を超えて多い
場合に漏油と判定する工程とを有することを特徴とする
ケーブルの漏油検知方法。1. A temperature change of an insulating oil in a cable is obtained based on a load current of the cable, a temperature change around the cable, and a thermal resistance and a specific heat of each part inside and outside the cable. the volume expansion coefficient of the insulating oil to calculate the amount of change in insulating oil in the cable by, Quai variation and supplied insulating oil to the cable in the cable in the insulating oil
Calculating the supply amount of the insulating oil to the cable based on the hydraulic pressure distribution in the cable longitudinal direction, and comparing the calculated value of the supply amount of the insulating oil with the actually measured value so that the measured value exceeds the predetermined amount. A step of determining oil leakage when the amount is large.
数カ所における温度データの変化と、ケーブルの内外各
部の熱抵抗及び比熱とに基づいてケーブル内の絶縁油の
温度変化を求め、このケーブル内絶縁油の温度変化と絶
縁油の体積膨張係数によってケーブル内の絶縁油の変化
量を算出し、このケーブル内絶縁油の変化量とケーブル
への絶縁油の供給油圧を基にケーブルへの絶縁油の供給
量を算出する工程と、この絶縁油の供給量の算出値と実
測値とを比較して実測値の方が所定量を超えて多い場合
に漏油と判定する工程とを有することを特徴とするケー
ブルの漏油検知方法。2. A temperature change of the insulating oil in the cable is obtained based on a load current of the cable, a change in temperature data at a plurality of locations on the cable, and a thermal resistance and a specific heat of each part inside and outside the cable. The amount of change in the insulating oil in the cable is calculated from the temperature change of the insulating oil and the volume expansion coefficient of the insulating oil, and based on the change in the insulating oil in the cable and the oil pressure supplied to the cable, the insulating oil Calculating the supply amount of the insulating oil, and comparing the calculated value of the supply amount of the insulating oil with the actually measured value, and determining that the oil leakage has occurred when the actually measured value is larger than a predetermined amount. Characteristic method of detecting oil leakage in cables.
る全長の温度分布データから算出されるケーブル自体の
表面温度の変化と、ケーブルの内外各部の熱抵抗及び比
熱とに基づいてケーブル内の絶縁油の温度変化を求め、
このケーブル内絶縁油の温度変化と絶縁油の体積膨張係
数によってケーブル内の絶縁油の変化量を算出し、この
ケーブル内絶縁油の変化量とケーブルへの絶縁油の供給
油圧を基にケーブルへの絶縁油の供給量を算出する工程
と、この絶縁油の供給量の算出値と実測値とを比較して
実測値の方が所定量を超えて多い場合に漏油と判定する
工程とを有することを特徴とするケーブルの漏油検知方
法。3. An insulating oil in a cable based on a load current of the cable, a change in a surface temperature of the cable itself calculated from temperature distribution data of the entire length of the optical fiber, and a thermal resistance and a specific heat of each part inside and outside the cable. The temperature change of
The amount of change in the insulating oil in the cable is calculated based on the change in the temperature of the insulating oil in the cable and the volume expansion coefficient of the insulating oil. Calculating the supply amount of the insulating oil, and comparing the calculated value of the supply amount of the insulating oil with the actually measured value and determining that the oil is leaking when the measured value is larger than a predetermined amount. A method for detecting oil leakage in a cable, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7210864A JP2854822B2 (en) | 1995-08-18 | 1995-08-18 | Cable oil leak detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7210864A JP2854822B2 (en) | 1995-08-18 | 1995-08-18 | Cable oil leak detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0954008A JPH0954008A (en) | 1997-02-25 |
| JP2854822B2 true JP2854822B2 (en) | 1999-02-10 |
Family
ID=16596372
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7210864A Expired - Lifetime JP2854822B2 (en) | 1995-08-18 | 1995-08-18 | Cable oil leak detection method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2854822B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5755161B2 (en) * | 2012-02-18 | 2015-07-29 | 株式会社ビスキャス | OF cable line degradation diagnosis method and OF cable line equipment suitable for it |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0228529A (en) * | 1988-07-19 | 1990-01-30 | Furukawa Electric Co Ltd:The | Detecting method for oil leak of cable line |
| JPH0755626A (en) * | 1993-08-06 | 1995-03-03 | Mitsubishi Electric Corp | Device and method for detecting liquid leakage |
-
1995
- 1995-08-18 JP JP7210864A patent/JP2854822B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0954008A (en) | 1997-02-25 |
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