JPH0415577A - Diagnostic method for insulation deterioration of cv cable - Google Patents
Diagnostic method for insulation deterioration of cv cableInfo
- Publication number
- JPH0415577A JPH0415577A JP12035890A JP12035890A JPH0415577A JP H0415577 A JPH0415577 A JP H0415577A JP 12035890 A JP12035890 A JP 12035890A JP 12035890 A JP12035890 A JP 12035890A JP H0415577 A JPH0415577 A JP H0415577A
- Authority
- JP
- Japan
- Prior art keywords
- current
- cable
- pulsating
- component
- 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.)
- Granted
Links
- 230000006866 deterioration Effects 0.000 title claims abstract description 28
- 238000009413 insulation Methods 0.000 title claims description 12
- 238000002405 diagnostic procedure Methods 0.000 title 1
- 238000000034 method Methods 0.000 claims description 14
- 240000005572 Syzygium cordatum Species 0.000 abstract description 9
- 235000006650 Syzygium cordatum Nutrition 0.000 abstract description 9
- 239000012212 insulator Substances 0.000 abstract description 7
- 238000012360 testing method Methods 0.000 abstract description 7
- 230000010354 integration Effects 0.000 abstract description 3
- 238000003745 diagnosis Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 238000001514 detection method Methods 0.000 description 5
- 239000004020 conductor Substances 0.000 description 3
- 230000001788 irregular Effects 0.000 description 3
- 229920003020 cross-linked polyethylene Polymers 0.000 description 2
- 239000004703 cross-linked polyethylene Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- 102100038915 Dynein axonemal assembly factor 3 Human genes 0.000 description 1
- 101000955739 Homo sapiens Dynein axonemal assembly factor 3 Proteins 0.000 description 1
- 206010044565 Tremor Diseases 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000011160 research 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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Relating To Insulation (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野コ
本発明は、ＣＶケーブル絶縁体の水トリー等による劣化
の程度を知見するための方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for determining the degree of deterioration of CV cable insulation due to water trees, etc.
［従来の技術］
一般的に、電カケープルは布設後の経年変化により電気
絶縁体の絶縁性能が低下する。特に、ＣＶケーブルでは
架橋ポリエヂレン絶縁体に樹状の亀裂が生じ、この亀裂
に水分が侵入する所謂水トリーの発生が絶縁劣化の主な
原因であることが知られている。このような絶縁性能の
低下は、放置すると進展して早晩大きな絶縁破壊事故に
つながる慣れがある。従って、ケーブルの絶縁抵抗の変
化を把握し、劣化を早期に発見することが極めて重要で
ある。[Prior Art] Generally, the insulation performance of the electric insulator of an electric cable deteriorates over time after installation. In particular, it is known that in CV cables, dendritic cracks occur in the crosslinked polyethylene insulator, and the occurrence of so-called water trees, in which water enters the cracks, is the main cause of insulation deterioration. If left untreated, this kind of deterioration in insulation performance will progress and sooner or later lead to a major dielectric breakdown accident. Therefore, it is extremely important to understand changes in cable insulation resistance and discover deterioration early.
ケーブル絶縁体の水トリー劣化に起因する絶縁抵抗の変
化を常時監視するーっの方法として、本出願人の提案に
かかる脈流検出法がある。脈流検出法とは、交流課電中
のケーヘプルの接地線を流れる電流を検出した場合、り
゛−プル絶縁体中に水トリーが存在すると概ね数Ｉ（Ｚ
以下の周期で変動する脈動電流が発生し、しかも水１・
り一劣化が激しい程この脈動電流成分は大きくなるとい
う新知見に基づいて案出されたものである。かかる脈動
電流により劣化診断を行う具体的手段としては、先ずロ
ーパスフィルタによって接地線電流から交流充電電流成
分を除去して脈流成分を取り出し、これを増幅して波形
表示手段に表示させ、該表示波形を時間解析する如き手
段が本出願人により提案されている。As a method for constantly monitoring changes in insulation resistance caused by water tree deterioration of cable insulators, there is a pulsating current detection method proposed by the present applicant. The pulsating current detection method means that when detecting the current flowing through the grounding wire of a cable pull while AC current is being applied, if a water tree exists in the pulsating insulator, the current will be approximately I(Z).
A pulsating current that fluctuates at the following frequency is generated, and water 1.
This was devised based on the new knowledge that the more severe the deterioration of the pulsating current component, the larger the pulsating current component becomes. As a specific means for diagnosing deterioration using such pulsating current, first, a low-pass filter removes the AC charging current component from the ground line current to extract the pulsating current component, amplifies this component, displays it on the waveform display means, and displays the pulsating current component. The applicant has proposed a means for time-analyzing waveforms.
［発明が解決しようとする課題１
しかしながら本発明者らが脈流法についてざらに研究を
重ねた結果、脈流成分を単に波形表示させたのみではそ
の時間解析が困難であることがわかった。すなわち、前
述の通り脈流成分は水１・り一劣化程度に応じてその大
きざが変化するので、脈流の大きざを検知−Ｊることか
当該劣化診断法においては重要となるのであるが、脈流
波形は極めて不定的な波形であり、該波形そのものから
脈流成分本来の大きざを評価するのは非常に困難である
ということを知見した。[Problem to be Solved by the Invention 1] However, as a result of extensive research into the pulsating flow method, the present inventors found that it is difficult to time-analyze the pulsating flow component simply by displaying it in a waveform. In other words, as mentioned above, the size of the pulsating flow component changes depending on the degree of water deterioration, so detecting the size of the pulsating flow is important in the deterioration diagnosis method. However, it has been found that the pulsating flow waveform is an extremely irregular waveform, and that it is very difficult to evaluate the original size of the pulsating flow component from the waveform itself.
従って本発明は、脈流法において、接地線より検出した
脈流成分の時間解析を容易とし、水１・り一劣化診断を
正確に行い得る方法を提供することを目的とする。Therefore, an object of the present invention is to provide a method that facilitates time analysis of pulsating flow components detected from a ground wire in the pulsating flow method, and enables accurate diagnosis of water deterioration.
［課題を解決するための手段］
本発明のＣＶケーブルの絶縁劣化診断方法は、測定対象
のＣ■ケーブルに交流電圧を印加し、その接地線電流よ
り脈流成分を検出し、該脈流成分を整流すると共に積分
して得られた直流出力信号に基ついて、り゛−プル絶縁
体の劣化の程度を検知することを特徴とづるものである
。[Means for Solving the Problem] The method for diagnosing insulation deterioration of a CV cable of the present invention applies an alternating current voltage to the C-cable to be measured, detects a pulsating current component from the ground wire current, and detects the pulsating current component. This method is characterized by detecting the degree of deterioration of the ripple insulator based on the DC output signal obtained by rectifying and integrating the current.
し作用」
脈流成分を整流して積分することにより、不定的な脈流
波形を定量的な準直流的波形に換算することかでざる。By rectifying and integrating the pulsating flow component, the irregular pulsating current waveform can be converted into a quantitative quasi-DC waveform.
従って、脈流本来の大ぎざが知見し易くなり、また（ｈ
分゛することによって突発的な雑音電流成分の影響を除
去することかでざる。Therefore, it becomes easier to see the original large serrations of the pulsating flow, and (h
The only way to do this is to remove the influence of sudden noise current components.
し実施例」
以下図面に基ついて本発明の一実施例を詳細に説明する
。EMBODIMENT OF THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.
第１図は本発明の劣化診断方法を実施するための回路構
成図である。図において、１は供試ＣＶケーブルであり
、１１は導体、１２は架橋ポリエチレン絶縁体、１３は
遮蔽層をそれぞれ示している。５は交流電源で、一端を
接地し、他端を供試ＣＶゲーブル１の導体１１に接続し
ている。なお、供試Ｃ■ケーブル］が活線状態の場合に
おいて本発明を実施するとぎは、印加されている線路電
圧をそのまま利用ずれば良く、この場合は交流電源５は
不要となる。FIG. 1 is a circuit diagram for implementing the deterioration diagnosis method of the present invention. In the figure, 1 is a test CV cable, 11 is a conductor, 12 is a crosslinked polyethylene insulator, and 13 is a shielding layer. 5 is an AC power supply, one end of which is grounded and the other end connected to the conductor 11 of the CV cable 1 under test. Note that when the present invention is carried out when the test cable C2 is in a live state, the applied line voltage may be used as is, and in this case, the AC power supply 5 is not required.
Ｇ ７は供試ＣＶケーブル１の遮蔽層１３と大地との間
を接続する接地線であり、接地線Ｇには変流器３が結合
されている。接地線Ｇ中を流れる接地線電流ｉｅは変流
器３によって検出され、該電流は測定器２に送出される
。接地線電流ｉｅの他の検出手段としては、接地線Ｇの
中間部に抵抗を挿入し、該抵抗の両端に現れる端子電圧
を利用する方法等が挙げられる。G7 is a grounding wire that connects the shielding layer 13 of the CV cable 1 under test and the ground, and the current transformer 3 is coupled to the grounding wire G. The ground line current ie flowing in the ground line G is detected by the current transformer 3 and sent to the measuring device 2. Other methods for detecting the ground line current ie include a method in which a resistor is inserted in the middle of the ground line G and a terminal voltage appearing at both ends of the resistor is utilized.
供試ＣＶケーブル１に交流電圧が印加されると、導体１
−１と遮蔽層１３との静電結合により印加交流電圧に応
じた電荷が誘起され、この時間変化のため印加交流電圧
の周波数と同程度の周期で変動する電流（交流充電電流
）が通常発生し、接地線Ｇ中を流れることとなる。これ
に加え、絶縁体１２に水ト・り一劣化が存在する場合に
は前述の脈動電流が重畳されることとなる。脈動電流と
は印加交流電圧に依存する電流以外の電流を言い、印加
交流電圧の周波数以下の周波数の電流である。従って水
トリー劣化ケーブルの接地線電流ｉｅ中には、交流充電
電流成分、脈動電流成分、及び何らかの影響で発生ずる
雑音電流成分が存在していることになる。When an AC voltage is applied to the test CV cable 1, the conductor 1
-1 and the shielding layer 13 induces a charge according to the applied AC voltage, and due to this time change, a current (AC charging current) that fluctuates at a period comparable to the frequency of the applied AC voltage is usually generated. Therefore, it will flow through the ground wire G. In addition to this, if the insulator 12 suffers from water damage, the above-mentioned pulsating current will be superimposed. The pulsating current refers to a current other than a current that depends on the applied alternating current voltage, and is a current having a frequency lower than the frequency of the applied alternating current voltage. Therefore, the ground line current ie of the water-tree deteriorated cable includes an alternating current charging current component, a pulsating current component, and a noise current component generated due to some influence.
測定器２は、例えば変流器３が検出しＬ二接地線電流ｉ
ｅから上記交流充電電流成分を除去して脈流成分を取り
出すローバスツーイルター（以下ＬＰＦ）２１、検出き
れた全脈流成分の中から特定周波数成分のみを選択出力
するバンドパスフィルター（以下ＢＰＦ）２２、この出
力信号を整流する検波回路２３、及び検波回路２３の出
力を平滑な直流信号出力とするための積分回路２４等か
らなっている。なお２５．２６はそれぞれの回路段階に
おいて信号を増幅するための増幅器である。そして積分
回路２４の出力、すなわち測定器２の出力は、ペンレコ
ーダやシンクロスコープ等の表示装置４において表示さ
れる。The measuring device 2 detects, for example, the current transformer 3 and the L2 grounding wire current i.
A low pass filter (hereinafter referred to as LPF) 21 removes the AC charging current component and extracts the pulsating current component from e, and a band pass filter (hereinafter referred to as BPF) selects and outputs only a specific frequency component from all detected pulsating current components. ) 22, a detection circuit 23 for rectifying this output signal, and an integration circuit 24 for converting the output of the detection circuit 23 into a smooth DC signal output. Note that 25 and 26 are amplifiers for amplifying signals in each circuit stage. The output of the integrating circuit 24, that is, the output of the measuring device 2, is displayed on a display device 4 such as a pen recorder or a synchroscope.
次いで、上述の絶縁劣化診断装置の動作を第２図を参照
しながら説明する。Next, the operation of the above-mentioned insulation deterioration diagnosing device will be explained with reference to FIG.
第２図（ａ）は、変流器３が検出した接地線電流１ｅの
電流波形を示しており、交流充電電流をべ一スとし、水
１・り一劣化の存在によって発生Ｊ−る脈流成分及び雑
音電流成分が重畳されＴニ形の波形となっている。この
ような接地線電流ｉｅばＬ Ｐ Ｆ２１に入力され、交
流充電電流成分が除去される、。Fig. 2(a) shows the current waveform of the grounding line current 1e detected by the current transformer 3, based on the AC charging current, and the pulse generated by the presence of water 1/1 deterioration. The current component and the noise current component are superimposed to form a T-shaped waveform. Such a ground line current is input to the LPF21, and the alternating current charging current component is removed.
供試ＣＶケーブルか活線状態の場合、交流充電電流の周
波数ば５０Ｈ７（又は６０ Ｈｚ ）であり、一方脈流
成分は概ね数１（ｚ以下の周波数であるので、Ｌ Ｐ
Ｆ ２ ］としては例えば１０Ｉ−ＩＺ程度以下の電流
成分を通過ぎせる如き回路を用いれば良い。When the test CV cable is in a live state, the frequency of the AC charging current is 50H7 (or 60 Hz), while the pulsating current component is approximately 1 (the frequency is less than z, so L P
F 2 ] may be a circuit that allows a current component of about 10I-IZ or less to pass through, for example.
Ｌ Ｐ Ｆ ２１−の出力（脈流成分）は非常に微弱な
信号であるので、増幅器２５により増幅し、しかる後Ｂ
ＰＦ２２に入力される。Ｂ Ｐ Ｆ ２２では脈流成分
の中から単一周波数信号（例えば］、 Ｉ−（ｚ ）を
取り出し、次段の増幅器２６でこの信号を増幅する。Since the output (pulsating flow component) of LPF 21- is a very weak signal, it is amplified by the amplifier 25, and then
It is input to PF22. The BPF 22 extracts a single frequency signal (for example, I-(z)) from the pulsating flow component, and amplifies this signal in the next stage amplifier 26.
第２図（ｂ）の電流波形は前記増幅器２６の出力波形を
示すものであり、この波形は脈流成分の中の単一周波数
信号成分を表している。ＢＰＦ２２を使用するのは、全
脈流成分を増幅すると雑音電流成分も同時に増幅してし
まい測定に悪影響を及ぼす可能性があるためで、ＢＰＦ
２２及び増幅器２６で脈流成分を狭帯域増幅することに
より雑音成分の影響を小ざくするためである。従って本
発明を実施するに際しては、上述のような脈流成分の狭
帯域増幅回路を使用することが望ましい。The current waveform in FIG. 2(b) shows the output waveform of the amplifier 26, and this waveform represents a single frequency signal component among the pulsating flow components. The reason for using BPF22 is that if all the pulsating current components are amplified, the noise current component will also be amplified at the same time, which may have an adverse effect on the measurement.
This is to reduce the influence of noise components by amplifying the pulsating flow components in a narrow band with the amplifiers 22 and 26. Therefore, when carrying out the present invention, it is desirable to use a narrow band amplification circuit for pulsating flow components as described above.
モして増幅器２６の出力は検波回路２３へ入力された整
流され、次いで積分回路２４を通過ざぜることにより第
２図＜ｃ＞の如と電流波形を得ることができる。The output of the amplifier 26 is input to the detection circuit 23, where it is rectified, and then passed through the integration circuit 24 to obtain a current waveform as shown in FIG. 2<c>.
第２図（ｂ）の波形において、振幅に若干の大小はある
ものの比較的安定した微動部ａ１と、振幅が突出的に犬
となる変動部ｂ１とが存在しているが、前記微動部ａ１
を水トリー劣化度合に応じて生ずる脈動電流として、変
動部ｂ１を突発的雑音電流としてとらえることができる
。従来は本波形をもって脈流成分の大ざきを評価してい
たが、微動部ａ、の波形は安定していないため正確な脈
流成分の大−きざを特定することが困難であった。そこ
で本発明の如く当該脈流成分を整流及び積分することに
より、第２図（Ｃ）に示すように、同図？
（ｂ）における変動部ｂ１は波形の突出する部分ｂ２と
して残存するものの、劣化診断に必要である微動部ａ１
は連続的に低いレベルの平滑な安定部ａ２に変換される
ことになる。劣化診断を行うに際してもよ、突出部ｂ２
シよ雑音として無視し、安定部ａ２を脈流成分の大きざ
に応じた直流出力としてとらえれば良く、第２図（ｂ）
の波形に比べ脈流成分本来の大ざざを評価するには非常
に都合が良くなるものである。In the waveform of FIG. 2(b), there is a fine movement part a1 which is relatively stable although the amplitude is slightly different, and a fluctuating part b1 where the amplitude is noticeably small.
can be regarded as a pulsating current that occurs depending on the degree of water tree deterioration, and the fluctuation part b1 can be regarded as a sudden noise current. Conventionally, the amplitude of the pulsating flow component has been evaluated using this waveform, but since the waveform of the micro-tremor part a is not stable, it has been difficult to accurately identify the amplitude of the pulsating flow component. Therefore, by rectifying and integrating the pulsating flow component as in the present invention, as shown in FIG. Although the fluctuation part b1 in (b) remains as a protruding part b2 of the waveform, the slight fluctuation part a1 is necessary for deterioration diagnosis.
is converted into a smooth stable part a2 of a continuously lower level. The protrusion b2 is also useful when diagnosing deterioration.
Just ignore it as noise and treat the stable part a2 as a DC output depending on the size of the pulsating flow component, as shown in Figure 2 (b).
This is very convenient for evaluating the original roughness of the pulsating flow component compared to the waveform of .
上述の積分回路２４としては例えばＣＲ積分回路を使用
することがでとるが、脈流成分をより直流的に変換して
評価を容易とするために時定数は長くすること力ζ好ま
しく、少なくともＣＲ＝５以上、好ましくはＣＲ＝２０
程度であれば良い。また、ＬＰＦ２１としては例えばＬ
Ｃ型の所謂定に型フィルタを使用することができ、ＢＰ
Ｆ２２及び増幅器２６の働ぎをするものとして例えば並
列Ｔ型ＣＲ回路（Ｔｗｉｎ−Ｔ型狭帯域増幅回路）を使
用することかでざる。For example, a CR integrator circuit can be used as the above-mentioned integrator circuit 24, but it is preferable to make the time constant long in order to convert the pulsating flow component into a DC component and make the evaluation easier. =5 or more, preferably CR=20
It's fine as long as it's a certain amount. Further, as the LPF 21, for example, L
A type filter can be used for the so-called definition of type C, and BP
For example, a parallel T-type CR circuit (Twin-T narrowband amplifier circuit) may be used as the F22 and the amplifier 26.
測定器２の出力は表示装置４にて波形表示させても良い
が、該出力は直流信号であるのでディジタル変換が容易
であり、この出力をＡ／Ｄ変換しコンピュータで出力処
理することもでざる。The output of the measuring instrument 2 may be displayed as a waveform on the display device 4, but since the output is a DC signal, it is easy to convert it into a digital signal, and this output can also be A/D converted and output processed by a computer. Colander.
［発明の効果］
以上説明した通りの本発明のＣＶケーブルの絶縁劣化診
断方法によれば、接地線より脈流成分を検出し、ざらに
整流して積分することにより、不定的な微動電流である
脈流成分を直流に変換するので、脈流成分本来の大きざ
を評価し易くなる。[Effects of the Invention] According to the method for diagnosing insulation deterioration of CV cables of the present invention as explained above, pulsating current components are detected from the ground wire, roughly rectified and integrated, thereby detecting irregular microcurrent currents. Since a certain pulsating flow component is converted into direct current, it becomes easier to evaluate the original size of the pulsating flow component.
すなわち脈流成分の微妙な大小を直流信号であるがため
判断し易くなるため、従って正確な水トリー劣化度合を
知見でざるものである。、ｉ−た脈流成分を積分するこ
とにより、雑音電流の影響も小ざくすることができる。That is, since it is a direct current signal, it is easy to judge the subtle magnitude of the pulsating flow component, and therefore it is impossible to know the exact degree of water tree deterioration. , i-, the influence of noise current can be reduced by integrating the pulsating flow components.
また脈流成分の大きざを直流成分に変換するのでＡ／Ｄ
変換が容易となり、パソコン等で劣化診断を行うのに有
利になるという利点もある。In addition, since the magnitude of the pulsating current component is converted into a DC component, the A/D
Another advantage is that conversion is easy and it is advantageous for deterioration diagnosis using a personal computer or the like.
第１図は本発明の劣化診断方法を実施するための回路構
成図、第２図（ａ）〜（ｃ）は第１図の回路における各
部の電流波形を表すグラフ図である。FIG. 1 is a circuit configuration diagram for implementing the deterioration diagnosis method of the present invention, and FIGS. 2(a) to 2(c) are graphs showing current waveforms at various parts in the circuit of FIG. 1.
Claims (1)
地線電流より脈流成分を検出し、該脈流成分を整流する
と共に積分して得られた直流出力信号に基づいて、ケー
ブル絶縁体の劣化の程度を検知することを特徴とするＣ
Ｖケーブルの絶縁劣化診断方法。An AC voltage is applied to the CV cable to be measured, a pulsating current component is detected from the ground wire current, and the pulsating current component is rectified and integrated to determine the deterioration of the cable insulation based on the obtained DC output signal. C characterized by detecting the degree of
Method for diagnosing insulation deterioration of V cable.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2120358A JP2893055B2 (en) | 1990-05-10 | 1990-05-10 | Diagnosis method for insulation deterioration of CV cable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2120358A JP2893055B2 (en) | 1990-05-10 | 1990-05-10 | Diagnosis method for insulation deterioration of CV cable |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0415577A true JPH0415577A (en) | 1992-01-20 |
| JP2893055B2 JP2893055B2 (en) | 1999-05-17 |
Family
ID=14784233
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2120358A Expired - Fee Related JP2893055B2 (en) | 1990-05-10 | 1990-05-10 | Diagnosis method for insulation deterioration of CV cable |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2893055B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0656543A2 (en) * | 1993-12-01 | 1995-06-07 | Sumitomo Wiring Systems, Ltd. | Withstand voltage-testing apparatus |
-
1990
- 1990-05-10 JP JP2120358A patent/JP2893055B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0656543A2 (en) * | 1993-12-01 | 1995-06-07 | Sumitomo Wiring Systems, Ltd. | Withstand voltage-testing apparatus |
| EP0656543A3 (en) * | 1993-12-01 | 1996-06-19 | Sumitomo Wiring Systems | Withstand voltage-testing apparatus. |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2893055B2 (en) | 1999-05-17 |
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