JP5305384B2 - Partial discharge light emission detection method and apparatus - Google Patents

Partial discharge light emission detection method and apparatus Download PDF

Info

Publication number
JP5305384B2
JP5305384B2 JP2008271606A JP2008271606A JP5305384B2 JP 5305384 B2 JP5305384 B2 JP 5305384B2 JP 2008271606 A JP2008271606 A JP 2008271606A JP 2008271606 A JP2008271606 A JP 2008271606A JP 5305384 B2 JP5305384 B2 JP 5305384B2
Authority
JP
Japan
Prior art keywords
gas
partial discharge
light emission
luminescence
discharge
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 - Fee Related
Application number
JP2008271606A
Other languages
Japanese (ja)
Other versions
JP2010101671A (en
Inventor
信也 大塚
知輝 原
裕太 中山
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.)
Kyushu Institute of Technology NUC
Original Assignee
Kyushu Institute of Technology NUC
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 Kyushu Institute of Technology NUC filed Critical Kyushu Institute of Technology NUC
Priority to JP2008271606A priority Critical patent/JP5305384B2/en
Publication of JP2010101671A publication Critical patent/JP2010101671A/en
Application granted granted Critical
Publication of JP5305384B2 publication Critical patent/JP5305384B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Installation Of Bus-Bars (AREA)
  • Testing Relating To Insulation (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
  • Gas-Insulated Switchgears (AREA)

Description

本発明は、電力分野や電気絶縁、高電圧分野、あるいは放電物理を取り扱う分野で、微弱な放電発光の発光強度を増加させ、絶縁診断を実施したり放電発光現象を測定する部分放電発光検出方法及び装置に関する。   The present invention relates to a partial discharge luminescence detection method for increasing the luminescence intensity of weak discharge luminescence and performing insulation diagnosis or measuring a discharge luminescence phenomenon in the electric power field, electrical insulation, high voltage field, or field dealing with discharge physics. And an apparatus.

電力機器や電気機器の高電圧化、コンパクト化が要求される中、これら機器の高電界化が進み、機器の絶縁は厳しくなっている。また、経年機器も増加している。このような背景のもと、機器の絶縁破壊を未然に防ぐ、あるいは絶縁異常を早期に検出し評価するために、絶縁破壊の前駆現象である部分放電信号の測定が行われている。現在は、部分放電信号として電流や、電磁波、弾性波の検出が主流であるが、これから光学技術、特に受光素子の性能が向上すると電気的ノイズに強い光学測定が注目されることが期待されている。   As electric devices and electric devices are required to have higher voltages and more compact, the electric fields of these devices have been increased, and the insulation of the devices has become severe. Aging equipment is also increasing. Under such circumstances, partial discharge signals, which are precursors of dielectric breakdown, are measured in order to prevent breakdown of equipment in advance or to detect and evaluate an insulation abnormality at an early stage. At present, detection of current, electromagnetic waves, and elastic waves is mainly used as partial discharge signals, but optical technology, especially optical measurement that is resistant to electrical noise is expected to attract attention as the performance of light receiving elements improves. Yes.

図１０は、特許文献１に記載の従来の光学測定による部分放電検出装置を示す概略構成図である。測定対象とする電力ケーブルの絶縁材料などの試料を、暗所内に設置する。さらにこの暗所に設けられた観測窓に、発光測定装置（光電子増倍管）の発光測定部を隙間なく密着させ、この発光測定装置に、発光量を表示することができるカウンタを接続する。そして、試料に電圧を印加したときの発光量を測定する。この発光量は、発光測定装置にて放電光の波長に相当する波長３００〜８００ｎｍの発光を検出すると同時に、カウンタに発光量が表示されるようになっている。   FIG. 10 is a schematic configuration diagram showing a conventional partial discharge detection apparatus based on optical measurement described in Patent Document 1. As shown in FIG. A sample such as an insulation material for the power cable to be measured is placed in a dark place. Further, a light emission measuring unit of a light emission measuring device (photomultiplier tube) is closely attached to the observation window provided in the dark place, and a counter capable of displaying the light emission amount is connected to the light emission measuring device. And the light-emission amount when a voltage is applied to a sample is measured. This light emission amount is displayed on the counter at the same time as the light emission measuring device detects light emission with a wavelength of 300 to 800 nm corresponding to the wavelength of the discharge light.

絶縁破壊の前駆現象である部分放電は、微弱な発光であり、かつ高速の現象であるから、一般に目視では観測できない。そのため、光学装置を用いて、イメージインテンシファイヤでゲインを上げ、かつトリガ機能とゲート機能を利用して、あるタイミングの像を捕らえて観測される。絶縁破壊が絶対におこらないと仮定できれば、ゲインを最大限にして発光強度を増幅して観測できる。一方で、そのような状況で絶縁破壊が起こると破壊発光は非常に強く、測定器が壊れる恐れがあり、微弱高速放電現象を感度よく安全に測定することが困難であった。また、測定器の価格は非常に高価であるため、故障した際の経済的損失は大きい。このために、測定器の保護を考えると、これまで安心してゲインを上げた絶縁破壊電圧近傍の部分放電観測ができなかった。受光素子の性能向上と共に、部分放電発光自体の発光強度が上がれば、検出感度も向上し、絶縁診断には有利となる。   Partial discharge, which is a precursory phenomenon of dielectric breakdown, is weak light emission and is a high-speed phenomenon, and therefore cannot generally be observed visually. Therefore, using an optical device, the gain is increased by an image intensifier, and an image at a certain timing is captured and observed using a trigger function and a gate function. If it can be assumed that dielectric breakdown never occurs, the gain can be maximized and the emission intensity can be amplified and observed. On the other hand, when dielectric breakdown occurs in such a situation, the breakdown light emission is very strong, and the measuring device may be broken, and it is difficult to measure the weak high-speed discharge phenomenon with high sensitivity and safety. Moreover, since the price of a measuring instrument is very expensive, the economic loss at the time of failure is large. For this reason, considering the protection of the measuring instrument, it has not been possible to observe the partial discharge near the breakdown voltage where the gain has been increased with peace of mind. If the light emission intensity of the partial discharge light itself increases with the improvement of the performance of the light receiving element, the detection sensitivity is improved, which is advantageous for insulation diagnosis.

ガス絶縁開閉機器（GIS, Gas Insulated Switch）は、遮断器・断路器・母線電線路・避雷器・計器用変成器・作業用接地装置などを、絶縁性が高い六フッ化硫黄(SF6)ガスが充てんされた単一の接地容器内に収めた縮小形開閉設備として知られている。このようなガス絶縁開閉機器に用いられている六フッ化硫黄(SF6)ガスは、絶縁性が高いものの、高価である。このため、SF6ガスの使用量を削減したり、或いは低温地域での液化防止のために、SF6/N2混合ガスが用いられている。窒素N2を混合しても絶縁性能は混合率に比例して低下せず、絶縁性能の低下は比較的低いため（シナジズム効果）、また、最近では温暖化防止の観点から混合されるものであるために、窒素N2の混合量は多く、SF6と同等あるいはそれを超える量を混合することが一般的であった（例えば、30％SF6/70％N2）。但し、絶縁性能の低下が低いとは言え、N2を混合することにより、絶縁性能が低下する。このため、SF6ガスのガス取り扱い基準（電力用SF6ガス取り扱い基準：電協研第54巻3号（1998）参照）によれば、SF6の純度について、以下のように記載されている。即ち、絶縁、遮断、通電の遮断器性能の中で、遮断性能がもっとも不純物の影響を受けると言われており、不純物濃度が３vol％以下であれば十分に安全であるものの、１０vol％以下であれば実用上支障は無いとされている。
特開平１１−２３１０１３号公報 Gas insulated switchgear (GIS, Gas Insulated Switch) is a highly insulating sulfur hexafluoride (SF 6 ) gas for circuit breakers, disconnectors, busbars, lightning arresters, instrument transformers, work grounding devices, etc. Is known as a reduced-size switchgear housed in a single grounded container filled with The sulfur hexafluoride (SF 6 ) gas used in such gas-insulated switchgear is expensive, although it has a high insulation property. Therefore, you can reduce the amount of SF 6 gas, or for liquefaction prevention of low temperature region, SF 6 / N 2 mixed gas is used. Even if nitrogen N 2 is mixed, the insulation performance does not decrease in proportion to the mixing ratio, and the decrease in insulation performance is relatively low (synergism effect). Recently, it is mixed from the viewpoint of preventing global warming. for some, the mixing amount of the nitrogen N 2 many, it has been common to mix an amount of more than equal to or a SF 6 (e.g., 30% SF 6/70% N 2). However, although the deterioration of the insulation performance is low, the insulation performance is lowered by mixing N 2 . For this reason, according to SF 6 gas handling standards (SF 6 handling standards for electric power: refer to Denki Kyoken Vol. 54 No. 3 (1998)), the purity of SF 6 is described as follows: . That is, among the circuit breaker performance of insulation, breaker, and energization, it is said that the breaker performance is most affected by impurities, and it is safe enough if the impurity concentration is 3 vol% or less, but it is 10 vol% or less. If there is, it is said that there is no practical problem.
JP-A-11-231013

そこで、本発明は、電力分野や電気絶縁、高電圧分野、あるいは放電物理を取り扱う分野で、ガス絶縁媒体である電気負性ガスの放電発光を、遮断性能に影響のない１０vol％以下で新たなガスを少量混合することで、絶縁体の性能を変化させないで、放電発光自体の発光強度を上げて、検出感度を向上させることを目的としている。これによって、微弱な発光であり、かつ高速の現象であるから、一般に目視では観測できない絶縁破壊の前駆現象である部分放電を観測して、絶縁診断を有利に行うことができる。   Therefore, the present invention provides a new discharge emission of an electronegative gas that is a gas insulating medium at 10 vol% or less that does not affect the shut-off performance in the electric power field, electrical insulation, high voltage field, or field dealing with discharge physics. The object is to improve the detection sensitivity by increasing the emission intensity of the discharge emission itself without changing the performance of the insulator by mixing a small amount of gas. Accordingly, since it is weak light emission and a high-speed phenomenon, it is possible to advantageously perform insulation diagnosis by observing a partial discharge, which is a precursor phenomenon of dielectric breakdown that cannot be generally observed visually.

本発明の部分放電発光検出方法は、圧力容器内部に高電圧を印加する導体を有し、かつ絶縁ガスを充填したガス絶縁機器を備えて、圧力容器内部の部分放電発光を検出して観察する。この絶縁ガスとしての電気負性ガスに0.1vol％〜10vol％、さらに望ましくは3vol％〜10vol％の窒素ガスN2を混入した混合ガスを用いて、部分放電発光の発光強度を上げて、検出感度を向上させることを特徴とする。 The partial discharge luminescence detection method of the present invention comprises a gas insulation device having a conductor for applying a high voltage inside a pressure vessel and filled with an insulating gas, and detects and observes partial discharge luminescence inside the pressure vessel. . The 0.1vol% ~10vol% to electrical negative gas as an insulating gas, more preferably using a mixed gas obtained by mixing 3vol% ~10vol% of nitrogen gas N 2, to increase the emission intensity of the partial discharge light emission, detection It is characterized by improving sensitivity.

また、本発明の部分放電発光検出装置は、圧力容器内部に高電圧を印加する導体を有し、かつ絶縁ガスを充填したガス絶縁機器と、圧力容器内部の部分放電発光を検出して観察することのできる光学測定装置を備える。この絶縁ガスとしての電気負性ガスに0.1vol％〜10vol％、さらに望ましくは3vol％〜10vol％の窒素ガスN2を混入した混合ガスを用いることを特徴とする。 Moreover, the partial discharge luminescence detection device of the present invention has a conductor for applying a high voltage inside the pressure vessel and is filled with an insulating gas, and detects and observes the partial discharge luminescence inside the pressure vessel. An optical measuring device capable of A mixed gas in which 0.1 vol% to 10 vol%, more preferably 3 vol% to 10 vol% of nitrogen gas N 2 is mixed with the electronegative gas as the insulating gas is used.

この混合ガスには、さらに、希ガスの一種あるいは複数種を混合することができる。   This mixed gas can further be mixed with one or more rare gases.

本発明によれば、電気負性ガス中の部分放電の発光強度を向上させ、部分放電発光の検出感度を上昇させることができる。ガスの絶縁特性を維持し、且つ管理基準に抵触しない条件（純度）で、ガス自体の放電発光強度を向上させることが可能となる。本発明によれば、絶縁性能に影響を与えることなく従来の２〜３倍、或いはそれ以上の強度で放電発光を観測できるようになる。   ADVANTAGE OF THE INVENTION According to this invention, the emitted light intensity of the partial discharge in electronegative gas can be improved, and the detection sensitivity of partial discharge luminescence can be raised. It is possible to improve the discharge luminescence intensity of the gas itself under conditions (purity) that maintain the insulating properties of the gas and do not conflict with the management standards. According to the present invention, it is possible to observe discharge luminescence with an intensity of 2 to 3 times or more than the conventional one without affecting the insulation performance.

また、本発明は、光学測定によるガス絶縁における絶縁異常の検出感度向上および絶縁異常の早期発見に貢献する。このため、ガス絶縁電力機器だけでなく、実験室の放電研究にも利用でき、発光現象を感度よく検出することができる。   In addition, the present invention contributes to an improvement in detection sensitivity of insulation abnormality in gas insulation by optical measurement and early detection of insulation abnormality. For this reason, it can be used not only for gas-insulated power equipment but also for laboratory discharge research, and can detect the luminescence phenomenon with high sensitivity.

以下、例示に基づき本発明を説明する。図１は、本発明に基づき構成されるガス絶縁機器に備えた部分放電発光検出装置を例示する図であり、（Ａ）は、ガス絶縁機器を軸方向から見た断面図であり、（Ｂ）は、観測窓を手前にしてガス絶縁機器の側面から見た概念図である。   Hereinafter, the present invention will be described based on examples. FIG. 1 is a diagram illustrating a partial discharge luminescence detection device provided in a gas insulation device configured according to the present invention, and (A) is a cross-sectional view of the gas insulation device viewed from the axial direction. ) Is a conceptual diagram viewed from the side of the gas insulation device with the observation window facing forward.

図１に示すガス絶縁機器は、例えばガス絶縁開閉機器GISであり、その機器内部に高電圧導体を備えた圧力容器と、内部の放電源の部分放電発光を観察することのできる観測フランジを備えている。圧力容器は、接地電位の筒状の金属容器から構成される。図示の放電源は、例えば、高電圧導体或いは接地した圧力容器内壁のような部分放電が起こり得る部位を示している。そして、この圧力容器内には、詳細は後述する本発明の特徴とする絶縁ガスが充填される。絶縁ガスとしては、電気負性ガス、例えば、SF6や、C3F8, C2F6, c-C4F8などのPFC系ガス、CF3Iガス、あるいはCO2ガスなどを用いることができる。 The gas insulated device shown in FIG. 1 is, for example, a gas insulated switchgear GIS, and includes a pressure vessel having a high voltage conductor inside the device, and an observation flange capable of observing partial discharge emission of the internal discharge source. ing. The pressure vessel is composed of a cylindrical metal vessel having a ground potential. The illustrated discharge source indicates a portion where a partial discharge such as a high voltage conductor or a grounded pressure vessel inner wall may occur. The pressure vessel is filled with an insulating gas, which will be described later in detail. As the insulating gas, an electronegative gas, for example, SF 6 or PFC gas such as C 3 F 8 , C 2 F 6 , cC 4 F 8 , CF 3 I gas, or CO 2 gas may be used. it can.

観測フランジは、一つのガス区画（ガス絶縁開閉機器GISでは絶縁スペーサで区分された範囲）に少なくとも１つは設置することが望ましい。観測フランジには、石英ガラス或いはアクリル窓などで構成した観測窓を設けると共に、この観測窓外部に、発光検出器（受光素子）を配置する。発光検出器としては、例えば、光電子増倍管(PMT)、或いは高感度のフォトダイオードを用いる。発光検出器の出力は発光強度の時間変化を示す。発光検出器には、部分放電発光（特に300nm〜600nmの波長領域）の検出感度が高い受光素子を用いる。受光素子は、ガス区画毎に設置することで、その区画の放電源の有無を評価できる。また、１つのガス区画に、複数の受光素子を設置することで、信号到達時間や強度差を検討でき、放電発生位置の推定が可能となる。受光素子の出力は光学測定装置（例えば、オシロスコープなどの波形観測装置）で観測する。光電子増倍管(PMT)は、直流電源で駆動するので（例えば800V）、その電源接続が必要となる。   It is desirable to install at least one observation flange in one gas section (a range separated by an insulating spacer in the gas-insulated switchgear GIS). The observation flange is provided with an observation window made of quartz glass or an acrylic window, and a light emission detector (light receiving element) is disposed outside the observation window. As the emission detector, for example, a photomultiplier tube (PMT) or a highly sensitive photodiode is used. The output of the luminescence detector shows the change over time of the luminescence intensity. For the light emission detector, a light receiving element having high detection sensitivity for partial discharge light emission (especially in a wavelength region of 300 nm to 600 nm) is used. By installing the light receiving element for each gas section, it is possible to evaluate the presence / absence of a discharge power source in the section. Further, by installing a plurality of light receiving elements in one gas section, it is possible to examine the signal arrival time and the intensity difference, and to estimate the discharge occurrence position. The output of the light receiving element is observed with an optical measurement device (for example, a waveform observation device such as an oscilloscope). Since the photomultiplier tube (PMT) is driven by a DC power supply (for example, 800V), it is necessary to connect the power supply.

また、部分放電発光が圧力容器タンク内を伝搬しやすいように、圧力容器タンク内壁及び高電圧導体は反射しやすい処理をすることが望ましい。受光素子取り付け部位のフランジ面も同様な処理をすることができる。また、受光素子の前に集光レンズを備えることができる。   Further, it is desirable that the inner wall of the pressure vessel tank and the high-voltage conductor be treated so that partial discharge light emission easily propagates in the pressure vessel tank. The same processing can be performed on the flange surface of the light receiving element mounting portion. Moreover, a condensing lens can be provided in front of the light receiving element.

図２は、図１とは異なる別の例の部分放電発光検出装置を備えたガス絶縁機器の軸方向から見た断面図である。図２の例においては、発光検出器の取付け位置のみが、図１に例示の構成とは相違する。図２の例において、発光検出器は、観測フランジの内部（圧力容器内部）に備えられ、発光検出器の電源線とか信号線は、観測フランジに設けた気密端子を通して、外部に導出される。発光検出器を機器内部に設置する場合は、観測窓は必要なく（逆に外部から光が入らないように）窓無しの板で封じきりとする。発光検出器の取付け位置を除いて、図１を参照して説明したような構成とすることができるので、その他の構成の詳細な説明は省略する。   FIG. 2 is a cross-sectional view of a gas insulating apparatus provided with a partial discharge light emission detecting device of another example different from FIG. In the example of FIG. 2, only the attachment position of the light emission detector is different from the configuration illustrated in FIG. In the example of FIG. 2, the light emission detector is provided inside the observation flange (inside the pressure vessel), and the power supply line or signal line of the light emission detector is led out through an airtight terminal provided on the observation flange. When installing a luminescence detector inside the equipment, the observation window is not necessary (and conversely, no light enters from the outside). Since it can be set as the structure demonstrated with reference to FIG. 1 except the attachment position of the light emission detector, detailed description of another structure is abbreviate | omitted.

次に、圧力容器内に充填される絶縁ガスについて説明する。この絶縁ガスとして、電気負性ガス（例えば、六フッ化硫黄ガスSF6）に0.1vol％〜10vol％の窒素ガスN2を混入した混合ガスを用いる。あるいは電気負性ガスに0.1vol％〜10vol％の窒素ガスN2とNeやXeガス、あるいはHe, ArやKrなど希ガスの一種あるいは複数種を混合する。ガス導入は、混ざりやすいように、タンク底面のガス導入口から行う。電気負性ガスが充填されている既存機器に対して窒素ガスを充填する場合、タンク底面から充填する。電気負性ガスで最も一般的なSF6ガスは重いガスのため、窒素を下から吹き上げるようにして充填することにより、混合を良好にすることができる。 Next, the insulating gas filled in the pressure vessel will be described. As this insulating gas, a mixed gas in which 0.1 vol% to 10 vol% nitrogen gas N 2 is mixed into an electronegative gas (for example, sulfur hexafluoride gas SF 6 ) is used. Alternatively, 0.1 vol% to 10 vol% of nitrogen gas N 2 and Ne or Xe gas, or one or more rare gases such as He, Ar, or Kr are mixed in the electronegative gas. The gas is introduced from the gas inlet at the bottom of the tank so that it can be easily mixed. When filling nitrogen gas into the existing equipment filled with electronegative gas, it is filled from the bottom of the tank. Since SF 6 gas, which is the most common electronegative gas, is heavier, it can be mixed well by filling it with nitrogen blown from below.

図３は、SF6に窒素ガスN2を加えていった際の発光強度を示すグラフである。（Ａ）は負極性放電を、（Ｂ）は正極性放電の場合である。いずれのグラフにおいても、横軸は部分放電電流ｉｐ（ｍＡ）を示し、縦軸は、部分放電発光強度Ｌ（任意単位a.u.）を示している。 FIG. 3 is a graph showing the emission intensity when nitrogen gas N 2 is added to SF 6 . (A) shows the case of negative polarity discharge, and (B) shows the case of positive polarity discharge. In any graph, the horizontal axis represents the partial discharge current ip (mA), and the vertical axis represents the partial discharge emission intensity L (arbitrary unit au).

測定条件は、以下の通りである。絶縁ガスを充填した圧力容器内に、電源側高電圧電極及び接地側電極を有する電極系を設置する。この電極系は、不平等な高電界部を模擬するために、電極間のギャップ1cm以上の針状電極（電源側高電圧電極）、及び平板電極（接地側電極）とした。この圧力容器には、観測窓を備え、その観測窓を通して部分放電発光を測定した。また、接地側電極に部分放電電流を測定できるように電流検出回路を取り付けた。負極性放電は、電源側電極に交流電圧の負極性の半サイクルが印加されている時間、また、正極性放電は、電源側電極に交流電圧の正極性の半サイクルが印加されている時間に測定した結果である。ガス圧力は、略1気圧であり、正確には1気圧SF6に他のガスを加えていったために、3％混入時は1.03気圧となる。測定は、混合ガスを所定の値に設定した後、印加電源電圧を上昇させ、部分放電を発生させた。そのときの放電電流及び発光強度を測定した。さらに、印加電源電圧を上昇させることにより増加する放電電流を、グラフの横軸に示している。但し、直流の一定電圧でも電流値は変化し、また、交流では、電圧位相により瞬時値が異なるため、同一の実効値電圧でも放電電流は変化する。 The measurement conditions are as follows. An electrode system having a power supply side high voltage electrode and a ground side electrode is installed in a pressure vessel filled with an insulating gas. This electrode system was a needle electrode (power supply side high voltage electrode) with a gap of 1 cm or more between electrodes and a flat plate electrode (ground side electrode) in order to simulate an unequal high electric field part. This pressure vessel was provided with an observation window, and partial discharge luminescence was measured through the observation window. A current detection circuit was attached to the ground side electrode so that the partial discharge current could be measured. Negative discharge is the time during which the negative polarity half cycle of the AC voltage is applied to the power supply side electrode, and positive polarity discharge is during the time during which the positive polarity half cycle of the AC voltage is applied to the power supply side electrode. It is the result of measurement. The gas pressure is approximately 1 atm. To be precise, other gases are added to 1 atm SF 6 , so that when 3% is mixed, it becomes 1.03 atm. In the measurement, the mixed gas was set to a predetermined value, and then the applied power supply voltage was increased to generate a partial discharge. The discharge current and light emission intensity at that time were measured. Furthermore, the horizontal axis of the graph shows the discharge current that increases as the applied power supply voltage is increased. However, the current value changes even at a constant DC voltage, and since the instantaneous value varies depending on the voltage phase in AC, the discharge current changes even at the same effective voltage.

図３に示すように、部分放電発光強度（y軸）は放電電流に依存する。窒素ガスN2の混合割合は、グラフ中に記号で示している。N2ガスの発光は、主に中性窒素励起分子の脱励起の際の発光（second positive band (SPB)の発光）である。N2＝０の場合を、記号＋で示している。N2を増加させるにつれて発光強度は増し、N2を0.1％（容量比）混合すると発光強度は、正極性では２倍程度に、負極性では３倍程度に増加し、さらに、N2を3％（容量比）混合すると発光強度は、正極性では１0倍に、負極性では20〜30倍に増加する。このように、N2を0.1％以上にすることによって、より望ましくは、３％以上にすることによって、圧力容器内部の部分放電発光を検出して観察するのに十分な発光強度となる。N2混合率をさらに増加すると、発光強度はさらに上昇するが、上述したように、不純物（N2）濃度は、絶縁性能を低下させないために、１０％以下にする必要がある。 As shown in FIG. 3, the partial discharge luminescence intensity (y-axis) depends on the discharge current. The mixing ratio of nitrogen gas N 2 is indicated by a symbol in the graph. The light emission of N 2 gas is mainly light emission at the time of deexcitation of neutral nitrogen excited molecules (light emission of second positive band (SPB)). The case of N 2 = 0 is indicated by the symbol +. Luminous intensity as to increase the N 2 is increased, the luminescence intensity and N 2 0.1% (volume ratio) mixed is about 2 times in the positive polarity, increased 3 times in the negative polarity, further, N 2 3 When mixed in% (volume ratio), the emission intensity increases 10 times for positive polarity and 20 to 30 times for negative polarity. Thus, by setting N 2 to 0.1% or more, more desirably 3% or more, the emission intensity is sufficient to detect and observe partial discharge emission inside the pressure vessel. When the N 2 mixing ratio is further increased, the emission intensity further increases. However, as described above, the impurity (N 2 ) concentration needs to be 10% or less so as not to deteriorate the insulating performance.

図４は、SF6に希ガスNe及び窒素ガスN2を加えていった際の発光強度を示すグラフである。（Ａ）は負極性放電を、（Ｂ）は正極性放電の場合である。いずれのグラフにおいても、横軸は部分放電電流ｉｐ（ｍＡ）を示し、縦軸は、部分放電発光強度Ｌ（任意単位）を示している。測定条件は、図３を参照して説明した上述の場合と同じである。Neだけを1％まで混合しても、殆ど発光強度に変化は無かった。1％のNeに加えて、さらにN2を2％混合すると発光強度は顕著に増加した。正極性放電では10〜30倍に、負極性放電では20倍に増加した。 FIG. 4 is a graph showing the emission intensity when noble gas Ne and nitrogen gas N 2 are added to SF 6 . (A) shows the case of negative polarity discharge, and (B) shows the case of positive polarity discharge. In any graph, the horizontal axis represents the partial discharge current ip (mA), and the vertical axis represents the partial discharge emission intensity L (arbitrary unit). The measurement conditions are the same as those described above with reference to FIG. Even when Ne alone was mixed up to 1%, there was almost no change in emission intensity. In addition to 1% Ne and 2% N 2 , the emission intensity increased significantly. The positive discharge increased 10 to 30 times, and the negative discharge increased 20 times.

図５は、SF6に希ガスAr及び窒素ガスN2を加えていった際の発光強度を示すグラフである。（Ａ）は負極性放電を、（Ｂ）は正極性放電の場合である。Arだけを1％まで混合しても、殆ど発光強度に変化は無かった。1％のArに加えて、さらにN2を2％混合すると発光強度は顕著に増加した。正極性放電では10〜20倍に、負極性放電では20〜30倍に増加した。 FIG. 5 is a graph showing emission intensity when rare gas Ar and nitrogen gas N 2 are added to SF 6 . (A) shows the case of negative polarity discharge, and (B) shows the case of positive polarity discharge. Even when Ar alone was mixed up to 1%, there was almost no change in emission intensity. In addition to 1% Ar, when 2% of N 2 was further mixed, the emission intensity significantly increased. The positive discharge increased 10 to 20 times, and the negative discharge increased 20 to 30 times.

図６は、SF6に、窒素ガスN2無しで、希ガスNe, Arを加えていった際の発光強度を示すグラフ（参考例）である。（Ａ）は負極性放電を、（Ｂ）は正極性放電の場合である。N2混合がない場合は、Neを1.5％加えても、さらにArを1.5％追加しても、顕著な発光強度の増加は無かった。 FIG. 6 is a graph (reference example) showing emission intensity when noble gases Ne and Ar are added to SF 6 without nitrogen gas N 2 . (A) shows the case of negative polarity discharge, and (B) shows the case of positive polarity discharge. In the absence of N 2 mixing, there was no significant increase in luminescence intensity even when 1.5% Ne was added or 1.5% Ar was added.

図７は、放電発光信号とノイズの識別を説明する図である。（Ａ）は、放電発光信号の場合であり、（Ｂ）はノイズの場合である。数秒から数10秒の測定（数10周期から数100周期）を行って、データを取得することで強度の異なる二つの分布の有無により放電信号かノイズかを区別する。交流電圧を印加している場合は、印加されている交流1サイクルに相当する時間を周期として、複数サイクル間信号を取得する。印加交流電圧の周期で重ねて測定すれば、電圧位相に応じたパタンが現れる。例えば、0度からの周期を使うと、結果はサイン波のような山なりになるが、90度付近から周期を取ると、コサイン波のような山なりパタンが現れる。このように、パタンの形はどの時点からの周期性を使うかによって変わるが、正極性と負極性の放電発光強度の相違による二つのパタンが出ることに変わりはない。このような場合、図７（Ａ）に示すように、発光強度の異なる二つの分布ができると、それはノイズでなく放電発光信号であることがわかる。強度の大きな方が負極性の放電である（図３〜図５参照）。ノイズ信号の場合、発光強度分布は、ランダムとなる。光学測定においても、測定系に電磁ノイズが混入する場合、あるいは光学測定装置に暗流が発生する場合に、本手法は有効である。これらノイズはランダムに発生し、印加電圧依存性はない。   FIG. 7 is a diagram for explaining the discrimination between the discharge light emission signal and noise. (A) is a case of a discharge light emission signal, and (B) is a case of noise. The measurement is performed for several seconds to several tens of seconds (several tens of cycles to several hundreds of cycles), and the data is acquired to distinguish between the discharge signal and the noise depending on the presence of two distributions having different intensities. When an AC voltage is applied, a signal for a plurality of cycles is acquired with a period corresponding to the applied AC cycle as a period. If the measurement is repeated with the period of the applied AC voltage, a pattern corresponding to the voltage phase appears. For example, if a period from 0 degrees is used, the result will be a sine wave-like mountain, but if the period is taken from around 90 degrees, a cosine wave-like mountain pattern will appear. As described above, the shape of the pattern changes depending on from which point the periodicity is used, but two patterns are generated depending on the difference between the positive and negative discharge luminescence intensities. In such a case, as shown in FIG. 7A, when two distributions having different emission intensities are formed, it is understood that it is not a noise but a discharge emission signal. The one where intensity | strength is larger is a negative polarity discharge (refer FIGS. 3-5). In the case of a noise signal, the emission intensity distribution is random. Even in optical measurement, this method is effective when electromagnetic noise is mixed in the measurement system or when dark current is generated in the optical measurement apparatus. These noises are randomly generated and do not depend on the applied voltage.

図８は、N2混入量を変化させた場合の絶縁破壊電圧VB、正極性・負極性部分放電開始電圧VPD+?の関係を示すグラフである。N2を混入しても、絶縁破壊電圧VB、正極性・負極性部分放電開始電圧VPD+?に低下は見られず、むしろ上昇していることが分かる。但し、図中に×印で示すように、圧力Pを上昇させた状態での実験データである。 FIG. 8 is a graph showing the relationship between the dielectric breakdown voltage V B and the positive / negative partial discharge start voltage V PD +? When the N 2 mixing amount is changed. It can be seen that even when N 2 is mixed, the dielectric breakdown voltage V B and the positive / negative partial discharge start voltage V PD +? Are not decreased but rather increased. However, it is experimental data in a state where the pressure P is increased, as indicated by x in the figure.

図９は、電気負性ガスとしてC3F8（八フッ化プロパン）を用い、この電気負性ガスに窒素ガスN2を加えていった際の発光強度を示すグラフである。（Ａ）は負極性放電を、（Ｂ）は正極性放電の場合である。いずれのグラフにおいても、横軸は部分放電電流ｉｐ（ｍＡ）を示し、縦軸は、部分放電発光強度Ｌ（任意単位a.u.）を示している。 FIG. 9 is a graph showing the emission intensity when C 3 F 8 (octafluoropropane) is used as the electronegative gas and nitrogen gas N 2 is added to the electronegative gas. (A) shows the case of negative polarity discharge, and (B) shows the case of positive polarity discharge. In any graph, the horizontal axis represents the partial discharge current ip (mA), and the vertical axis represents the partial discharge emission intensity L (arbitrary unit au).

測定条件は、以下の通りである。C3F8絶縁ガスを充填した圧力容器内（73kPa）に、電源側高電圧電極及び接地側電極を有する電極系を設置する。この電極系は、上述の例と同じく、電極間のギャップ1cm以上の針状電極（電源側高電圧電極）、及び平板電極（接地側電極）とした。N2は圧力比が0, 0.1, 1, 3, 5, 10%となるように加えた。電圧=19,22,25 kVrms をそれぞれ印加して、5回ずつ測定した。 The measurement conditions are as follows. An electrode system having a power-side high-voltage electrode and a ground-side electrode is installed in a pressure vessel (73 kPa) filled with C 3 F 8 insulating gas. As in the above example, this electrode system was a needle electrode (power supply side high voltage electrode) having a gap of 1 cm or more between the electrodes and a plate electrode (ground side electrode). N 2 was added so that the pressure ratio was 0, 0.1, 1, 3, 5, 10%. Voltage = 19,22,25 kVrms was applied, and measurement was performed 5 times.

C3F8（八フッ化プロパン）ガスの場合も、図９に見られるように、N2を添加すると発光強度は上昇する傾向がある。同じ電流値で見るとN2濃度が高くなるほど発光強度は大きくなることがわかる。但し、N2混合率を上げ過ぎると電流が小さくなり、それに伴い発光強度が低下する傾向も見られる。窒素ガスN2の混入は、0.1vol％〜10vol％が望ましい。 Also in the case of C 3 F 8 (octafluoropropane) gas, as shown in FIG. 9, the emission intensity tends to increase when N 2 is added. From the same current value, it can be seen that the emission intensity increases as the N 2 concentration increases. However, if the N 2 mixing ratio is increased too much, the current decreases, and the light emission intensity tends to decrease accordingly. Nitrogen gas N 2 is preferably mixed in an amount of 0.1 vol% to 10 vol%.

本発明に基づき構成されるガス絶縁機器に備えた部分放電発光検出装置を例示する図であり、（Ａ）は、ガス絶縁機器を軸方向から見た断面図であり、（Ｂ）は、観測窓を手前にしてガス絶縁機器の側面から見た概念図である。It is a figure which illustrates the partial discharge luminescence detection apparatus with which the gas insulation apparatus comprised based on this invention was equipped, (A) is sectional drawing which looked at the gas insulation apparatus from the axial direction, (B) is observation It is the conceptual diagram seen from the side of the gas insulation apparatus with the window facing forward. 図１とは異なる別の例の部分放電発光検出装置を備えたガス絶縁機器の軸方向から見た断面図である。It is sectional drawing seen from the axial direction of the gas insulation apparatus provided with the partial discharge light emission detection apparatus of another example different from FIG. SF6に窒素ガスN2を加えていった際の発光強度を示すグラフである。The SF 6 is a graph showing the emission intensity at the time of going by adding nitrogen gas N 2. SF6に希ガスNe及び窒素ガスN2を加えていった際の発光強度を示すグラフである。Is a graph showing the emission intensity at the time of going by adding a rare gas Ne and nitrogen gas N 2 to SF 6. SF6に希ガスAr及び窒素ガスN2を加えていった際の発光強度を示すグラフである。Is a graph showing the emission intensity at the time of going by adding a rare gas Ar and the nitrogen gas N 2 to SF 6. SF6に、窒素ガスN2無しで、希ガスNe, Arを加えていった際の発光強度を示すグラフ（参考例）である。In SF 6, without the nitrogen gas N 2, a noble gas Ne, graph showing the emission intensity at the time of going by adding Ar (Reference Example). 放電発光信号とノイズの識別を説明する図である。It is a figure explaining discrimination of a discharge luminescence signal and noise. N2混入量を変化させた場合の絶縁破壊電圧VB、正極性・負極性部分放電開始電圧VPD+?の関係を示すグラフである。6 is a graph showing a relationship between a dielectric breakdown voltage V B and a positive / negative partial discharge start voltage V PD +? When the amount of N 2 mixed is changed. C3F8に窒素ガスN2を加えていった際の発光強度を示すグラフである。Is a graph showing the emission intensity at the time of going by adding nitrogen gas N 2 to C 3 F 8. 従来の光学測定による部分放電検出装置を示す概略構成図である。It is a schematic block diagram which shows the partial discharge detection apparatus by the conventional optical measurement.

Claims (11)

圧力容器内部に高電圧を印加する導体を有し、かつ絶縁ガスを充填したガス絶縁機器を備えて、圧力容器内部の部分放電発光を検出して観察する部分放電発光検出方法において、
前記絶縁ガスとしての電気負性ガスに0.1vol％〜10vol％の窒素ガスN2を混入した混合ガスを用いて、部分放電発光の発光強度を上げて、検出感度を向上させ、かつ、
部分放電発光検出は、少なくとも所定時間行い、その発光強度の分布を取得し、或いは、前記高電圧を印加する導体に交流電圧を印加している場合は、印加されている交流1サイクルに相当する時間を周期として、複数サイクル間信号を取得することで、強度の異なる二つの分布の有無により放電信号かノイズかを区別することを特徴とする部分放電発光検出方法。 In the partial discharge luminescence detection method for detecting and observing partial discharge luminescence inside the pressure vessel, comprising a gas insulation device filled with an insulating gas, having a conductor for applying a high voltage inside the pressure vessel,
Using a mixed gas in which 0.1 vol% to 10 vol% nitrogen gas N 2 is mixed into the electronegative gas as the insulating gas, the emission intensity of partial discharge light emission is increased, the detection sensitivity is improved , and
Partial discharge luminescence detection is performed for at least a predetermined time, and the distribution of the luminescence intensity is acquired, or when an AC voltage is applied to the conductor to which the high voltage is applied, it corresponds to an applied AC cycle. A partial discharge light emission detection method characterized in that a signal between a plurality of cycles is acquired with time as a period to distinguish between a discharge signal and noise depending on the presence or absence of two distributions having different intensities . 前記混合ガスは、さらに、希ガスの一種あるいは複数種を混合した請求項１に記載の部分放電発光検出方法。 The partial discharge luminescence detection method according to claim 1, wherein the mixed gas is further mixed with one or more kinds of rare gases. 圧力容器内部に高電圧を印加する導体を有し、かつ絶縁ガスを充填したガス絶縁機器と、圧力容器内部の部分放電発光を検出して観察することのできる光学測定装置を備えた部分放電発光検出装置において、
前記絶縁ガスとしての電気負性ガスに0.1vol％〜10vol％の窒素ガスN2を混入した混合ガスを用い、かつ、
部分放電発光検出は、少なくとも所定時間行い、その発光強度の分布を取得し、或いは、前記高電圧を印加する導体に交流電圧を印加している場合は、印加されている交流1サイクルに相当する時間を周期として、複数サイクル間信号を取得することで、強度の異なる二つの分布の有無により放電信号かノイズかを区別することを特徴とする部分放電発光検出装置。 Partial discharge light emission with a gas insulation device that has a conductor for applying a high voltage inside the pressure vessel and filled with an insulating gas, and an optical measuring device that can detect and observe partial discharge emission inside the pressure vessel In the detection device,
Using a mixed gas in which 0.1 vol% to 10 vol% nitrogen gas N 2 is mixed into the electronegative gas as the insulating gas , and
Partial discharge luminescence detection is performed for at least a predetermined time, and the distribution of the luminescence intensity is acquired, or when an AC voltage is applied to the conductor to which the high voltage is applied, it corresponds to an applied AC cycle. A partial discharge luminescence detection apparatus that distinguishes between a discharge signal and noise based on the presence or absence of two distributions having different intensities by acquiring a signal between a plurality of cycles with time as a period . 絶縁スペーサで区分されたガス区画毎に少なくとも一つの観測フランジを備え、該観測フランジの内部或いは外部に部分放電発光の波長領域の検出感度が高い発光検出器を備え、その出力を光学測定装置で観測する請求項３に記載の部分放電発光検出装置。 At least one observation flange is provided for each gas section divided by an insulating spacer, and a light emission detector having high detection sensitivity in the wavelength region of partial discharge light emission is provided inside or outside the observation flange, and the output thereof is measured by an optical measuring device. The partial discharge luminescence detection device according to claim 3 to be observed. 前記観測フランジには、観測窓を設け、この観測窓外部に、前記発光検出器を配置した請求項４に記載の部分放電発光検出装置。 The partial discharge light emission detection device according to claim 4, wherein an observation window is provided on the observation flange, and the light emission detector is disposed outside the observation window. 前記発光検出器として、光電子増倍管或いはフォトダイオードを用いる請求項４に記載の部分放電発光検出装置。 The partial discharge luminescence detection apparatus according to claim 4, wherein a photomultiplier tube or a photodiode is used as the luminescence detector. 前記発光検出器は、ガス区画毎に少なくとも１つ設置することで、その区画の放電源の有無を評価し、或いはガス区画毎に複数設置することで、信号到達時間や強度差に基づき、放電発生位置の推定を行う請求項４に記載の部分放電発光検出装置。 By installing at least one light emission detector for each gas compartment, it is possible to evaluate the presence or absence of a discharge power source in that compartment, or to install a plurality of light emission detectors for each gas compartment, so that discharge can be performed based on the signal arrival time and intensity difference. The partial discharge luminescence detection apparatus according to claim 4, wherein the generation position is estimated. 前記観測フランジの内部に前記発光検出器を備え、該発光検出器の電源線及び信号線は、観測フランジに設けた気密端子を通して外部に導出する請求項４に記載の部分放電発光検出装置。 The partial discharge light emission detection device according to claim 4, wherein the light emission detector is provided inside the observation flange, and a power supply line and a signal line of the light emission detector are led out through an airtight terminal provided on the observation flange. 前記混合ガスは、さらに、希ガスの一種あるいは複数種を混合した請求項３に記載の部分放電発光検出装置。 The partial discharge luminescence detection apparatus according to claim 3, wherein the mixed gas is further mixed with one or more kinds of rare gases. 前記圧力容器底面にガス導入口を備え、電気負性ガスが充填されている圧力容器に対してその底面から窒素ガス或いは希ガスを充填する請求項３又は９に記載の部分放電発光検出装置。 The partial discharge luminescence detection device according to claim 3 or 9, wherein a gas introduction port is provided on the bottom surface of the pressure vessel, and a pressure vessel filled with an electronegative gas is filled with nitrogen gas or a rare gas from the bottom surface. 前記電気負性ガスは、SF6や、C3F8, C2F6, c-C4F8を含むPFC系ガス、CF3Iガス、あるいはCO2ガスである請求項３に記載の部分放電発光検出装置。
4. The partial discharge according to claim 3, wherein the electronegative gas is SF 6 , PFC-based gas containing C 3 F 8 , C 2 F 6 , or cC 4 F 8 , CF 3 I gas, or CO 2 gas. Luminescence detection device.
JP2008271606A 2008-10-22 2008-10-22 Partial discharge light emission detection method and apparatus Expired - Fee Related JP5305384B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008271606A JP5305384B2 (en) 2008-10-22 2008-10-22 Partial discharge light emission detection method and apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008271606A JP5305384B2 (en) 2008-10-22 2008-10-22 Partial discharge light emission detection method and apparatus

Publications (2)

Publication Number Publication Date
JP2010101671A JP2010101671A (en) 2010-05-06
JP5305384B2 true JP5305384B2 (en) 2013-10-02

Family

ID=42292445

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008271606A Expired - Fee Related JP5305384B2 (en) 2008-10-22 2008-10-22 Partial discharge light emission detection method and apparatus

Country Status (1)

Country Link
JP (1) JP5305384B2 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5854468B2 (en) 2012-01-25 2016-02-09 国立大学法人九州工業大学 Non-contact discharge evaluation method and apparatus
JP6103353B2 (en) 2013-01-15 2017-03-29 国立大学法人九州工業大学 Non-contact discharge test method and apparatus
CN107359537A (en) * 2017-09-01 2017-11-17 云南电网有限责任公司电力科学研究院 One kind visualization switchgear
JP7112608B1 (en) * 2021-04-30 2022-08-03 株式会社東光高岳 voltage transformer
CN113433428B (en) * 2021-05-10 2023-09-01 广西电网有限责任公司玉林供电局 Synergistic effect analysis method for multi-element mixed insulating gas

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58170310A (en) * 1982-03-30 1983-10-06 株式会社富士電機総合研究所 Method and device for sealing gas substitution of gas insulated electric device
JPH075222A (en) * 1993-06-16 1995-01-10 Fuji Electric Co Ltd Partial electric discharge detector
JPH11231013A (en) * 1998-02-10 1999-08-27 Fujikura Ltd Partial discharge detecting method
JPH11287838A (en) * 1998-04-02 1999-10-19 Takaoka Electric Mfg Co Ltd Partial discharge detection device of gas insulation equipment
JP4134403B2 (en) * 1998-11-06 2008-08-20 株式会社日立製作所 Power transmission / distribution equipment
JP2002084611A (en) * 2000-09-07 2002-03-22 Toshiba Corp Monitoring device for gas-insulated apparatus
JP2002233012A (en) * 2001-01-31 2002-08-16 Mitsubishi Electric Corp Gas-insulated electrical apparatus
JP2009300357A (en) * 2008-06-17 2009-12-24 Kyushu Institute Of Technology Apparatus for measuring weak discharge emission

Also Published As

Publication number Publication date
JP2010101671A (en) 2010-05-06

Similar Documents

Publication Publication Date Title
JP5305384B2 (en) Partial discharge light emission detection method and apparatus
Toigo et al. Partial discharge behavior of protrusion on high voltage conductor in GIS/GIL under high voltage direct current: Comparison of SF 6 and SF 6 alternative gases
US6426627B2 (en) Vacuum switch including vacuum-measurement devices, switchgear using the vacuum switch, and operation method thereof
JP6482632B2 (en) Partial discharge detection method and partial discharge detection apparatus for electric power equipment
KR20130055077A (en) Partial discharge monitoring equipment using rogowsky coil
JP2009300357A (en) Apparatus for measuring weak discharge emission
Bartnikas A comment concerning the rise times of partial discharge pulses
Spyker et al. An evaluation of diagnostic techniques relevant to arcing fault current interrupters for direct current power systems in future aircraft
Kasten et al. Partial discharge measurements in air and argon at low pressures with and without a dielectric barrier
Sellars et al. UHF detection of leader discharges in SF/sub 6
Binns et al. Optical discharge detection in SF/sub 6/-insulated systems
Kamarol et al. Determination of gas pressure in vacuum interrupter based on partial discharge
Hui et al. The relationship between partial discharge behavior and the degradation of 10 kV XLPE cable joints
Lee et al. Impulse breakdown characteristics of the plane-to-plane electrode system with a needle-shaped protrusion in SF6
Ren et al. Partial discharge test under standard oscillating impulses on a gas-insulated bus with artificial metal particle defects on the insulator surface
Ren et al. Partial discharge measurement and analysis at standard oscillating switching and lightning impulses on a GIS with artificial protrusion defects
HU189555B (en) Vacuum-chamber circuit-breaker with vacuum indicator
Boggs The case for frequency domain PD testing in the context of distribution cable
Nyamupangedengu Time-varying partial discharge spectral characteristics in solid polymer insulation
Michelarakis et al. Triple point surface discharge photography in atmospheric gases using intensified high-speed camera system
Lundgaard et al. Evaluation of dielectric liquids by measurement of their partial discharge characteristics
Hayakawa et al. Partial discharge inception characteristics by different measuring methods in magnet wire under surge voltage application
Graf et al. Determination of Inception and Breakdown Voltages of N2—SF6 Gas Mixtures in Strong Inhomogeneous Fields
Truong et al. Characterization of streamers in liquid nitrogen under AC voltages using UHF techniques
RU2441303C2 (en) Method and device for protection of electric equipment against breakdown, having insulation gap and surfaces of electrodes isolated from each other by liquid dielectric

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20111020

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20120820

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20130311

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20130402

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20130411

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20130618

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20130620

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

Ref document number: 5305384

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

LAPS Cancellation because of no payment of annual fees