JPH09184866A - Diagnostic method for degradation of cable under electrification - Google Patents
Diagnostic method for degradation of cable under electrificationInfo
- Publication number
- JPH09184866A JPH09184866A JP34337795A JP34337795A JPH09184866A JP H09184866 A JPH09184866 A JP H09184866A JP 34337795 A JP34337795 A JP 34337795A JP 34337795 A JP34337795 A JP 34337795A JP H09184866 A JPH09184866 A JP H09184866A
- Authority
- JP
- Japan
- Prior art keywords
- cable
- output
- circuit
- capacitor
- deterioration
- 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
Links
Landscapes
- Testing Relating To Insulation (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、ＣＶケーブルの
絶縁劣化を活線下で正確に診断するためのケーブル活線
下劣化診断方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable live-line deterioration diagnosis method for accurately diagnosing insulation deterioration of a CV cable under live line.
【０００２】[0002]
【従来の技術】ケーブルに交流電源電圧が印加されてい
る状態、即ち活線下でそのケーブルの絶縁劣化を診断す
る方法として、例えば、特開平５−２６４６４２号公報
に示されるように、ケーブルに流れる損失分（抵抗分）
電流中の高調波電流の大きさを指標にして劣化度合を診
断する方法が提案されている。この方法では、ＣＶケー
ブルの遮蔽層と基準電位との間を接続する接地線より損
失分電流を求め、この電流中に含まれる高調波電流の大
きさから劣化の程度を判定する。2. Description of the Related Art As a method for diagnosing insulation deterioration of a cable under the condition that an AC power supply voltage is applied to the cable, that is, under a live line, for example, as shown in Japanese Patent Laid-Open No. 5-264642, Loss flow (resistance)
There has been proposed a method of diagnosing the degree of deterioration using the magnitude of the harmonic current in the current as an index. In this method, the loss current is obtained from the ground line connecting the shield layer of the CV cable and the reference potential, and the degree of deterioration is determined from the magnitude of the harmonic current contained in this current.
【０００３】[0003]
【発明が解決しようとする課題】損失電流中の高調波電
流の大きさから劣化の程度を判定する上記の診断方法で
は、電源に高調波が重畳している場合、劣化していない
ケーブルでも大きな高調波電流が観測され、劣化と誤認
するため、ケーブル絶縁体の劣化を正確に検知すること
が困難である。In the above-mentioned diagnostic method for judging the degree of deterioration from the magnitude of the harmonic current in the loss current, when the power supply is superposed with harmonics, even a cable which is not deteriorated is large. It is difficult to accurately detect the deterioration of the cable insulator because the harmonic current is observed and is mistaken for the deterioration.
【０００４】この発明は、かかる欠点を解消して絶縁劣
化の診断を正しく行えるようにすることを課題としてい
る。An object of the present invention is to eliminate such drawbacks and to correctly diagnose insulation deterioration.
【０００５】[0005]
【課題を解決するための手段】上記の課題を解決するた
め、この発明においては、交流電源電圧が印加されてい
るケーブルに流れる電流の基本周波数成分をゼロになる
ように調整する回路を挿入し、この回路により、基本周
波数成分をゼロに調整したときに検出される電流の基本
周波数に対する高調波成分の大きさによってケーブルの
劣化度合を判定する。また、交流電源電圧が印加されて
いるケーブルの導体と接地との間に抵抗とコンデンサ及
びケーブル絶縁体から成るブリッジ回路を形成し、さら
に、ブリッジ中性点間の電位差を取出す回路を設け、こ
の回路からバンドパスフィルタを通って出力される前記
交流電源の周波数成分を、前記抵抗の抵抗値調整及びコ
ンデンサの容量調整でキャンセルしてゼロにし、この状
態で前記バンドパスフィルタから取出す他周波成分の出
力の大きさから絶縁劣化の度合を判定する方法で劣化診
断を行う。In order to solve the above problems, the present invention inserts a circuit for adjusting the fundamental frequency component of the current flowing through a cable to which an AC power supply voltage is applied so as to be zero. With this circuit, the degree of deterioration of the cable is determined by the magnitude of the harmonic component of the current detected when the fundamental frequency component is adjusted to zero. In addition, a bridge circuit composed of a resistor, a capacitor and a cable insulator is formed between the conductor of the cable to which the AC power supply voltage is applied and the ground, and a circuit for extracting the potential difference between the bridge neutral points is provided. The frequency component of the AC power source output from the circuit through the bandpass filter is canceled by resistance value adjustment of the resistor and capacitance adjustment of the capacitor to zero, and in this state, other frequency components of the other frequency components extracted from the bandpass filter are canceled. Deterioration diagnosis is performed by a method of determining the degree of insulation deterioration from the magnitude of output.
【０００６】絶縁劣化の程度は、他周波数成分の出力の
大きさと劣化度合との関係を予め求めておき、そのデー
タと実際に得られた出力の大きさを照らし合わせて判断
すればよい。The degree of insulation deterioration may be determined by previously determining the relationship between the magnitude of the output of the other frequency component and the degree of degradation, and comparing the data with the magnitude of the output actually obtained.
【０００７】なお、交流電源周波数キャンセル後にバン
ドパスフィルタから取出す他周波数成分は、キャンセル
した交流電源周波数の奇数倍であるのが好ましい。It is preferable that the other frequency component extracted from the bandpass filter after the AC power supply frequency is canceled is an odd multiple of the canceled AC power supply frequency.
【０００８】[0008]
【作用】電位差取出し回路のバンドパスフィルタから交
流電源の周波数を出力し、その電位差出力を抵抗及びコ
ンデンサによる調整で最小にする。これにより、ケーブ
ルの容量成分、抵抗成分及び交流電源波形がキャンセル
される。よって、交流電源に高調波成分が含まれていて
もその殆んどがキャンセルされる。The frequency of the AC power supply is output from the bandpass filter of the potential difference extraction circuit, and the potential difference output is minimized by adjusting the resistance and the capacitor. This cancels the capacitance component, resistance component, and AC power supply waveform of the cable. Therefore, even if the AC power supply contains harmonic components, most of them are canceled.
【０００９】このキャンセル状態では、ケーブルが健全
で抵抗成分の電流−電圧特性が直線であるなら出力電圧
はゼロになる筈であり、ケーブルが水トリー劣化してい
て電流−電圧特性が非直線であれば、それによって発生
する電流による電圧のみが出力される。In this cancel state, if the cable is sound and the current-voltage characteristic of the resistance component is linear, the output voltage should be zero, and the cable is degraded in the water tree and the current-voltage characteristic is non-linear. If so, only the voltage due to the current generated thereby is output.
【００１０】この発明では、交流電源の周波数成分をキ
ャンセルした後、バンドパスフィルタを他周波数に切替
えてケーブルの抵抗成分に含まれる他周波成分を検出す
るので、キャンセル後にバンドパスフィルタから出力さ
れる電流はケーブル絶縁体の劣化によって生じる電流の
みとなっており、その電流による電圧の周波数成分の大
きさから劣化の度合を判定するため、電源に含まれる高
調波成分の影響が無くなり、正確な劣化診断が行える。According to the present invention, after canceling the frequency component of the AC power source, the bandpass filter is switched to another frequency and the other frequency component contained in the resistance component of the cable is detected, so that it is output from the bandpass filter after cancellation. The current is only the current generated by the deterioration of the cable insulator, and the degree of deterioration is determined from the magnitude of the frequency component of the voltage due to that current, so the influence of the harmonic components contained in the power supply disappears and accurate deterioration is eliminated. Can diagnose.
【００１１】なお、バンドパスフィルタから取出す他周
波数成分が交流電源周波数の奇数倍であると、水トリー
劣化したケーブルから検出される抵抗成分には、特に、
電源周波数の奇数倍の高調波成分が多く含まれるため、
安定した出力が得られる。If the other frequency component extracted from the bandpass filter is an odd multiple of the AC power supply frequency, the resistance component detected from the cable deteriorated by the water tree is
Since it contains many harmonic components that are odd multiples of the power frequency,
A stable output is obtained.
【００１２】[0012]
【発明の実施の形態】図１に、この発明の方法の実施に
用いる劣化診断装置の具体例（回路図）を示す。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a specific example (circuit diagram) of a deterioration diagnosing device used for carrying out the method of the present invention.
【００１３】診断対象ケーブル１０の導体と遮蔽層との
間の絶縁抵抗及び絶縁容量の等価回路ＣＢは、図のよう
に抵抗成分ｒx 及び容量成分Ｃx の並列接続として表わ
せる。本診断装置は、負荷側端子１１と接地端子１２を
有する交流電源Ｅを有しており、この電源Ｅの負荷側端
子１１をケーブルの導体に接続する。また、ケーブル１
０の導体には標準コンデンサＣ０を接続し、さらに、こ
の標準コンデンサＣ０を第１接続点１３を介して並列配
置の可変抵抗Ｒ１と可変コンデンサＣ１に接続し、接地
する。An equivalent circuit CB of insulation resistance and insulation capacitance between the conductor of the cable to be diagnosed 10 and the shield layer can be represented as a parallel connection of a resistance component rx and a capacitance component Cx as shown in the figure. The diagnostic apparatus has an AC power supply E having a load side terminal 11 and a ground terminal 12, and the load side terminal 11 of the power supply E is connected to a conductor of a cable. Also, cable 1
A standard capacitor C0 is connected to the conductor of 0, and this standard capacitor C0 is further connected to the variable resistor R1 and the variable capacitor C1 arranged in parallel via the first connection point 13 and grounded.
【００１４】ケーブル１０の遮蔽層と接地間には抵抗Ｒ
を第２接続点１４を介して接続する。A resistor R is provided between the shield layer of the cable 10 and the ground.
Are connected via the second connection point 14.
【００１５】また、第１接続点１３と第２接続点１４間
の電位差を差動アンプ１５で増幅し、バンドパスフィル
タ１６に通して取出す回路を設ける。Further, a circuit for amplifying the potential difference between the first connection point 13 and the second connection point 14 by the differential amplifier 15 and passing it through the bandpass filter 16 is provided.
【００１６】このような、回路構成にしてバンドパスフ
ィルタ１６の通過帯域を支流電源Ｅの周波数に合わせ、
このフィルタ１６から出力される交流電源周波数成分
を、可変抵抗Ｒ１の抵抗値と可変コンデンサＣ１の容量
調整によってキャンセルし、ゼロにする。With such a circuit configuration, the pass band of the band pass filter 16 is adjusted to the frequency of the tributary power source E,
The frequency component of the AC power output from the filter 16 is canceled by adjusting the resistance value of the variable resistor R1 and the capacitance of the variable capacitor C1 to zero.
【００１７】ブリッジ回路の平衡条件、 Ｃ1 ＲＲ1 ＋Ｃx ｒx Ｒ＝Ｃ0 ｒx Ｒ1 ω2 Ｃ1 Ｃx Ｒ1 ｒx ＝１ ただし ω＝２πｆ ｆ：電源周波数 が成り立つとき、バンドパスフィルタ１６の出力から交
流電源の周波数成分が除かれる。The balance condition of the bridge circuit, C 1 RR 1 + C x r x R = C 0 r x R 1 ω 2 C 1 C x R 1 r x = 1 where ω = 2πf f: power supply frequency The frequency component of the AC power supply is removed from the output of the pass filter 16.
【００１８】次に、電源の周波数成分がキャンセルされ
たこの状態で、バンドパスフィルタの通過帯域を他周波
数（好ましくは、キャンセルした電源周波数の奇数倍の
周波数）に合わせると、ケーブル絶縁体の劣化によって
生じる電流による電圧の周波数成分のみが出力される。
そこで、この出力の大きさを、事前に求めておいた出力
と絶縁劣化の度合の関係を示すデータと照らし合わせ、
劣化の程度を判定する。Next, when the pass band of the band pass filter is adjusted to another frequency (preferably a frequency that is an odd multiple of the canceled power frequency) in this state where the frequency component of the power source is canceled, the cable insulator deteriorates. Only the frequency component of the voltage due to the current generated by is output.
Therefore, the magnitude of this output is compared with the data obtained in advance and showing the relationship between the output and the degree of insulation deterioration,
Determine the degree of deterioration.
【００１９】図２及び図３に、調整回路でケーブルに流
れる電流の基本周波数成分をゼロに調整したときに検出
される高調波電流（これはケーブル絶縁体の劣化によっ
て生じる）の大きさと、ケーブルのＡＣ破壊電圧との関
係及びその高調波電流とトリー長との関係を調べたデー
タを示す。FIGS. 2 and 3 show the magnitude of the harmonic current detected when the fundamental frequency component of the current flowing through the cable is adjusted to zero by the adjusting circuit (this is caused by deterioration of the cable insulation), and the cable. 2 shows the data obtained by examining the relationship between the AC breakdown voltage and the harmonic current and the tree length.
【００２０】これから、高調波電流の大きさによりケー
ブル絶縁体の劣化度合を判定できることが判る。From this, it can be seen that the degree of deterioration of the cable insulator can be determined by the magnitude of the harmonic current.
【００２１】[0021]
【発明の効果】以上述べたように、この発明の劣化診断
方法によれば、ケーブルにつなぐ電源に高調波が重畳し
ていても、その高調波による悪影響が排除されるため、
ケーブルの劣化の程度を正確に判定でき、使用中のケー
ブルの交換時期の適正化、開発中のケーブルからの信頼
性の高い評価データ収集などに役立つ。As described above, according to the deterioration diagnosing method of the present invention, even if a harmonic is superposed on the power source connected to the cable, the adverse effect of the harmonic is eliminated.
The degree of deterioration of the cable can be accurately determined, which is useful for optimizing the replacement time of the cable in use and collecting highly reliable evaluation data from the cable under development.
【図１】この発明の方法の実施に用いる診断装置の一例
の回路図FIG. 1 is a circuit diagram of an example of a diagnostic device used for carrying out the method of the present invention.
【図２】高調波電流とＡＣ破壊電圧との関係の調査デー
タを示す図表FIG. 2 is a chart showing survey data on the relationship between harmonic current and AC breakdown voltage.
【図３】高調波電流とトリー長との関係の調査データを
示す図表FIG. 3 is a chart showing survey data on the relationship between harmonic current and tree length.
Ｅ 交流電源 Ｃ０ 標準コンデンサ Ｒ１ 可変抵抗 Ｃ１ 可変コンデンサ ＣＢ ケーブルの等価回路 ｒx ケーブルの抵抗成分 Ｃx ケーブルの容量成分 Ｒ 抵抗 １０ ケーブル １１ 負荷側端子 １２ 接地端子 １３ 第１接続点 １４ 第２接続点 １５ 差動アンプ １６ バンドパスフィルタ E AC power supply C0 Standard capacitor R1 Variable resistor C1 Variable capacitor CB Equivalent circuit of cable rx Cable resistance component Cx Cable capacitance component R resistance 10 Cable 11 Load side terminal 12 Ground terminal 13 First connection point 14 Second connection point 15 Difference Dynamic amplifier 16 bandpass filter
Claims (2)
に流れる電流の基本周波数成分をゼロになるように調整
する回路を挿入し、この回路により、基本周波数成分を
ゼロに調整したときに検出される電流の基本周波数に対
する高調波成分の大きさによってケーブルの劣化度合を
判定するケーブルの活線下劣化診断方法。1. A circuit for adjusting the fundamental frequency component of a current flowing through a cable to which an AC power supply voltage is applied so as to be zero is inserted, and this circuit detects when the fundamental frequency component is adjusted to zero. A method for diagnosing the deterioration of a cable under the live line by judging the degree of deterioration of the cable based on the magnitude of the harmonic component with respect to the fundamental frequency of the current.
の導体と接地との間に抵抗とコンデンサ及びケーブル絶
縁体から成るブリッジ回路を形成し、さらに、ブリッジ
中性点間の電位差を取出す回路を設け、この回路からバ
ンドパスフィルタを通って出力される前記交流電源の周
波数成分を、前記抵抗の抵抗値調整及びコンデンサの容
量調整でキャンセルしてゼロにし、この状態で前記バン
ドパスフィルタから取出す他周波成分の出力の大きさか
ら絶縁劣化の度合を判定するケーブルの活線下劣化診断
方法。2. A circuit for forming a bridge circuit composed of a resistor, a capacitor and a cable insulator between a conductor of a cable to which an AC power supply voltage is applied and the ground, and for extracting a potential difference between bridge neutral points. The frequency component of the AC power supply output from this circuit through the bandpass filter is canceled by the resistance value adjustment of the resistor and the capacitance adjustment of the capacitor to zero, and is taken out from the bandpass filter in this state. A method for diagnosing under-wire degradation of a cable that determines the degree of insulation degradation from the output of frequency components.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34337795A JPH09184866A (en) | 1995-12-28 | 1995-12-28 | Diagnostic method for degradation of cable under electrification |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34337795A JPH09184866A (en) | 1995-12-28 | 1995-12-28 | Diagnostic method for degradation of cable under electrification |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09184866A true JPH09184866A (en) | 1997-07-15 |
Family
ID=18361049
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34337795A Pending JPH09184866A (en) | 1995-12-28 | 1995-12-28 | Diagnostic method for degradation of cable under electrification |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09184866A (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999053329A1 (en) * | 1998-04-14 | 1999-10-21 | The Furukawa Electric Co., Ltd. | Method of diagnosing deterioration of electric power cable |
| US6361378B1 (en) | 1999-01-11 | 2002-03-26 | Sumitomo Wiring Systems, Ltd. | Connector with a side retainer |
| KR100449275B1 (en) * | 2002-03-11 | 2004-09-22 | 학교법인 성균관대학 | Method for condition monitoring of power cable using harmonics and system thereof |
| JP2012042422A (en) * | 2010-08-23 | 2012-03-01 | Kansai Electric Power Co Inc:The | Power cable deterioration determining method |
| CN104698355A (en) * | 2015-03-20 | 2015-06-10 | 成都吉普斯能源科技有限公司 | On-line diagnosing method of high-voltage cable partial discharge |
| CN107607821A (en) * | 2017-10-25 | 2018-01-19 | 广西电网有限责任公司电力科学研究院 | A kind of controllable middle pressure XLPE cable ageing test apparatus of harmonic content |
| EP3318883A1 (en) * | 2016-11-07 | 2018-05-09 | Fluke Corporation | Non-contact voltage measurement system |
| US10352967B2 (en) | 2016-11-11 | 2019-07-16 | Fluke Corporation | Non-contact electrical parameter measurement systems |
| US10551416B2 (en) | 2018-05-09 | 2020-02-04 | Fluke Corporation | Multi-sensor configuration for non-contact voltage measurement devices |
| US10557875B2 (en) | 2018-05-09 | 2020-02-11 | Fluke Corporation | Multi-sensor scanner configuration for non-contact voltage measurement devices |
| US10677876B2 (en) | 2018-05-09 | 2020-06-09 | Fluke Corporation | Position dependent non-contact voltage and current measurement |
| US10746767B2 (en) | 2018-05-09 | 2020-08-18 | Fluke Corporation | Adjustable length Rogowski coil measurement device with non-contact voltage measurement |
| US10775409B2 (en) | 2018-05-09 | 2020-09-15 | Fluke Corporation | Clamp probe for non-contact electrical parameter measurement |
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-
1995
- 1995-12-28 JP JP34337795A patent/JPH09184866A/en active Pending
Cited By (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999053329A1 (en) * | 1998-04-14 | 1999-10-21 | The Furukawa Electric Co., Ltd. | Method of diagnosing deterioration of electric power cable |
| US6361378B1 (en) | 1999-01-11 | 2002-03-26 | Sumitomo Wiring Systems, Ltd. | Connector with a side retainer |
| KR100449275B1 (en) * | 2002-03-11 | 2004-09-22 | 학교법인 성균관대학 | Method for condition monitoring of power cable using harmonics and system thereof |
| JP2012042422A (en) * | 2010-08-23 | 2012-03-01 | Kansai Electric Power Co Inc:The | Power cable deterioration determining method |
| CN104698355A (en) * | 2015-03-20 | 2015-06-10 | 成都吉普斯能源科技有限公司 | On-line diagnosing method of high-voltage cable partial discharge |
| US10119998B2 (en) | 2016-11-07 | 2018-11-06 | Fluke Corporation | Variable capacitance non-contact AC voltage measurement system |
| EP3318883A1 (en) * | 2016-11-07 | 2018-05-09 | Fluke Corporation | Non-contact voltage measurement system |
| CN108072782A (en) * | 2016-11-07 | 2018-05-25 | 弗兰克公司 | Non-contact voltage measuring system |
| CN108072782B (en) * | 2016-11-07 | 2022-01-04 | 弗兰克公司 | Non-contact voltage measuring system |
| US10352967B2 (en) | 2016-11-11 | 2019-07-16 | Fluke Corporation | Non-contact electrical parameter measurement systems |
| CN107607821A (en) * | 2017-10-25 | 2018-01-19 | 广西电网有限责任公司电力科学研究院 | A kind of controllable middle pressure XLPE cable ageing test apparatus of harmonic content |
| US10677876B2 (en) | 2018-05-09 | 2020-06-09 | Fluke Corporation | Position dependent non-contact voltage and current measurement |
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