JP2014032047A - Insulation deterioration diagnostic method for insulating oil in electrical devices - Google Patents
Insulation deterioration diagnostic method for insulating oil in electrical devices Download PDFInfo
- Publication number
- JP2014032047A JP2014032047A JP2012171440A JP2012171440A JP2014032047A JP 2014032047 A JP2014032047 A JP 2014032047A JP 2012171440 A JP2012171440 A JP 2012171440A JP 2012171440 A JP2012171440 A JP 2012171440A JP 2014032047 A JP2014032047 A JP 2014032047A
- Authority
- JP
- Japan
- Prior art keywords
- oil
- water
- insulating oil
- amount
- mol
- 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 47
- 238000009413 insulation Methods 0.000 title claims abstract description 42
- 238000002405 diagnostic procedure Methods 0.000 title abstract 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 286
- 239000002253 acid Substances 0.000 claims abstract description 72
- 238000000034 method Methods 0.000 claims abstract description 52
- 238000005227 gel permeation chromatography Methods 0.000 claims abstract description 20
- 229920006395 saturated elastomer Polymers 0.000 claims description 114
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 78
- 238000004090 dissolution Methods 0.000 claims description 58
- 238000004364 calculation method Methods 0.000 claims description 34
- 230000015556 catabolic process Effects 0.000 claims description 28
- 238000003745 diagnosis Methods 0.000 claims description 19
- 238000009739 binding Methods 0.000 claims description 9
- 238000000354 decomposition reaction Methods 0.000 claims description 9
- 230000002378 acidificating effect Effects 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 238000010525 oxidative degradation reaction Methods 0.000 claims description 4
- 238000009834 vaporization Methods 0.000 claims description 3
- 230000008016 vaporization Effects 0.000 claims description 3
- 238000005259 measurement Methods 0.000 abstract description 26
- 239000003921 oil Substances 0.000 description 345
- 235000019198 oils Nutrition 0.000 description 345
- 238000010828 elution Methods 0.000 description 13
- 238000001179 sorption measurement Methods 0.000 description 12
- 125000003118 aryl group Chemical group 0.000 description 11
- 239000000126 substance Substances 0.000 description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 10
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 10
- DCAYPVUWAIABOU-UHFFFAOYSA-N hexadecane Chemical compound CCCCCCCCCCCCCCCC DCAYPVUWAIABOU-UHFFFAOYSA-N 0.000 description 8
- BKIMMITUMNQMOS-UHFFFAOYSA-N nonane Chemical compound CCCCCCCCC BKIMMITUMNQMOS-UHFFFAOYSA-N 0.000 description 8
- 238000011088 calibration curve Methods 0.000 description 7
- 125000000753 cycloalkyl group Chemical group 0.000 description 7
- 239000000243 solution Substances 0.000 description 7
- MWPLVEDNUUSJAV-UHFFFAOYSA-N anthracene Chemical compound C1=CC=CC2=CC3=CC=CC=C3C=C21 MWPLVEDNUUSJAV-UHFFFAOYSA-N 0.000 description 6
- 230000007423 decrease Effects 0.000 description 6
- 230000014509 gene expression Effects 0.000 description 6
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 6
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 238000010998 test method Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- SNRUBQQJIBEYMU-UHFFFAOYSA-N dodecane Chemical compound CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 description 3
- 239000010735 electrical insulating oil Substances 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 239000012212 insulator Substances 0.000 description 3
- 239000011630 iodine Substances 0.000 description 3
- 229910052740 iodine Inorganic materials 0.000 description 3
- 239000002480 mineral oil Substances 0.000 description 3
- 235000010446 mineral oil Nutrition 0.000 description 3
- 229940094933 n-dodecane Drugs 0.000 description 3
- 238000005191 phase separation Methods 0.000 description 3
- IFLREYGFSNHWGE-UHFFFAOYSA-N tetracene Chemical compound C1=CC=CC2=CC3=CC4=CC=CC=C4C=C3C=C21 IFLREYGFSNHWGE-UHFFFAOYSA-N 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 238000002835 absorbance Methods 0.000 description 2
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 238000005443 coulometric titration Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000005868 electrolysis reaction Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 239000012046 mixed solvent Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 2
- 238000004448 titration Methods 0.000 description 2
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 235000019482 Palm oil Nutrition 0.000 description 1
- 235000019484 Rapeseed oil Nutrition 0.000 description 1
- AOADSHDCARXSGL-ZMIIQOOPSA-M alkali blue 4B Chemical compound CC1=CC(/C(\C(C=C2)=CC=C2NC2=CC=CC=C2S([O-])(=O)=O)=C(\C=C2)/C=C/C\2=N\C2=CC=CC=C2)=CC=C1N.[Na+] AOADSHDCARXSGL-ZMIIQOOPSA-M 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- XMBWDFGMSWQBCA-UHFFFAOYSA-M iodide Chemical compound [I-] XMBWDFGMSWQBCA-UHFFFAOYSA-M 0.000 description 1
- 229940006461 iodide ion Drugs 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000009149 molecular binding Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002540 palm oil Substances 0.000 description 1
- 239000012188 paraffin wax Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
Images
Landscapes
- Housings And Mounting Of Transformers (AREA)
Abstract
Description
本発明は油入電気機器の絶縁劣化診断に関するものであり、さらに詳しくは、電気機器に充填された絶縁油の飽和水分溶解量を計算から推定し、その結果に基づき当該絶縁油の絶縁破壊電圧を推定し、絶縁油の絶縁劣化具合を診断する方法に関する。 The present invention relates to diagnosis of insulation deterioration of oil-filled electrical equipment. More specifically, the saturated water dissolution amount of insulation oil filled in electrical equipment is estimated from the calculation, and based on the result, the dielectric breakdown voltage of the insulation oil is estimated. The present invention relates to a method for diagnosing the degree of insulation deterioration of insulating oil.
油入電気機器に充填される絶縁油には鉱物系絶縁油や合成油やパームヤシ油、菜種油などの植物系絶縁油が挙げられる。
絶縁油を油入電気機器に充填する主な目的は、機器の冷却と絶縁耐力の確保である。たとえば電力用変圧器の場合、その用途にもよるが、数千〜数十万Ｖの高電圧が印加される場合もあり、油が劣化し絶縁破壊電圧が低下すると、機器の絶縁破壊を起こす危険性が高まる。
Examples of the insulating oil filled in the oil-filled electrical equipment include mineral insulating oil, synthetic insulating oil, palm palm oil, and rapeseed oil.
The main purpose of filling the oil-filled electrical equipment with the insulating oil is to cool the equipment and ensure the dielectric strength. For example, in the case of a power transformer, depending on the application, a high voltage of thousands to hundreds of thousands of volts may be applied, and if the oil degrades and the dielectric breakdown voltage decreases, the dielectric breakdown of the equipment occurs. Increased risk.
油入電気機器において絶縁油中の水分量が多くなると、絶縁破壊電圧が低下する。油には油と相分離しない程度のわずかな量の水分を溶解可能であり、油に溶解している水分量は油中水分量と呼ばれる。この油中水分量が多くなると油は劣化する。
よって、絶縁油中に水分がなるべく混入しないように、絶縁油の製造過程で脱水したり、油の容器を密閉したりする。また、油入電気機器の定期点検等により混入した絶縁油中水分量を測定し、絶縁油の健全性を確認することが行われている。
しかし、油中水分量がどの程度油の特性を劣化させるかは、油に含まれる水分の存在形態によるため、一概に水分量が多いからといって不具合を生じるわけではない。
When the amount of moisture in the insulating oil in the oil-filled electrical device increases, the dielectric breakdown voltage decreases. A small amount of water that does not phase separate from oil can be dissolved in the oil, and the amount of water dissolved in the oil is called the amount of water in the oil. When the moisture content in the oil increases, the oil deteriorates.
Therefore, in order to prevent moisture from being mixed into the insulating oil as much as possible, it is dehydrated during the manufacturing process of the insulating oil or the oil container is sealed. In addition, the moisture content in the insulating oil mixed by periodic inspection of oil-filled electrical equipment is measured to confirm the soundness of the insulating oil.
However, how much the amount of water in the oil deteriorates the characteristics of the oil depends on the form of the water contained in the oil, and therefore a large amount of water does not cause a problem.
油中に溶解できる水分量の最大値は飽和水分溶解量と呼ばれ、それを越して油に水分が混じると、溶け込めなくなった水分子は油から相分離し、そのような相分離した水分は上記の不具合を生じさせやすい。
水分量が飽和水分溶解量以下でも、飽和水分溶解量に近くなると、水分子が数分子集団を形成しながら油中でそれ以上大きな水分子に成長せず相分離しない状態が実現する。
そのような水分子の小集団も上記の不具合を生じさせやすいため、飽和水分溶解量に対して油中水分がどれだけ溶解しているかを表す割合が重要になると、本発明者は考えている。すなわち、油中水分量を飽和水分溶解量で除した水分飽和度が絶縁油に不具合を生じさせる可能性を示す尺度になり得ると考えられる。
The maximum amount of water that can be dissolved in oil is called saturated water solubility, and when water is mixed with oil beyond that, water molecules that cannot be dissolved will phase-separate from the oil, and such phase-separated water will be It is easy to cause the above problems.
Even when the water content is less than or equal to the saturated water solubility, when the water content is close to the saturated water solubility, a state in which water molecules do not grow into larger water molecules in oil and phase separation does not occur while forming several molecular groups.
Since such a small group of water molecules is likely to cause the above-mentioned problems, the present inventor believes that a ratio representing how much moisture in the oil is dissolved with respect to the saturated water dissolution amount is important. . That is, it is considered that the water saturation obtained by dividing the amount of water in oil by the amount of dissolved saturated water can be a scale indicating the possibility of causing problems in the insulating oil.
飽和水分溶解量の測定方法の一例は以下の通りである。
油を湿度１００％の恒温槽に静置または撹拌しながら適切な時間をかけてその雰囲気と平衡になるように置き、その後カールフィッシャー法などで油中水分量を測定する。
ただし、この方法では、３０〜４０℃程度以下の比較的低温においては、飽和に達するまでの時間は１週間以上かかり、飽和していると判定するのが困難であるために、測定が不正確になりやすい。また、６０℃以上の比較的高温においては、水分が過飽和になりやすいことやカールフィッシャー法で水分量を測定する際に油が冷えてしまい、測定値に影響することがあり、測定が不正確になりやすい問題がある。
An example of a method for measuring the saturated water dissolution amount is as follows.
The oil is placed in a constant temperature bath with a humidity of 100% so as to equilibrate with the atmosphere over an appropriate period of time while stirring, and then the moisture content in the oil is measured by the Karl Fischer method or the like.
However, in this method, at a relatively low temperature of about 30 to 40 ° C. or less, it takes 1 week or more to reach saturation, and it is difficult to determine that it is saturated. It is easy to become. In addition, at a relatively high temperature of 60 ° C. or higher, moisture tends to be supersaturated, and when measuring the water content by the Karl Fischer method, the oil may be cooled, which may affect the measured value, resulting in inaccurate measurement. There is a problem that tends to become.
油入電気機器の場合、低温における絶縁破壊電圧は重要である。稼働中の電気機器を停止すると絶縁油の温度が低下する。特に、寒冷地などでは絶縁油の温度が０℃以下に下がることがある。絶縁油の温度が下がると飽和水分溶解量が下がり、溶解していた水分が凝集して水滴になり、絶縁破壊電圧が低下する場合がある。そのような状況で、電気機器を再稼働させると絶縁破壊による事故が起きる可能性がある。
また、稼働中の電気機器が過負荷などの原因により絶縁油の温度が１５０℃程度以上になると、電気機器の内部で絶縁油に触れているセルロース系絶縁物に含まれていた水分が蒸発し、絶縁油中に気泡が発生し、これが絶縁上の弱点となり、絶縁破壊に至る可能性が生じると考えられる。よって、低温および高温における飽和水分溶解量を正確に知ることが、稼働中の絶縁油の絶縁破壊電圧を推定するために必要となる。
For oil-filled electrical equipment, the breakdown voltage at low temperatures is important. When the electrical equipment in operation is stopped, the temperature of the insulating oil decreases. In particular, the temperature of the insulating oil may drop to 0 ° C. or lower in cold regions. When the temperature of the insulating oil decreases, the amount of saturated water dissolved decreases, the dissolved water aggregates into water droplets, and the dielectric breakdown voltage may decrease. In such a situation, an accident due to dielectric breakdown may occur if the electrical equipment is restarted.
Also, if the temperature of the insulating oil exceeds about 150 ° C due to overloading of the operating electrical equipment, the moisture contained in the cellulosic insulation that is in contact with the insulating oil inside the electrical equipment will evaporate. It is considered that bubbles are generated in the insulating oil, which becomes a weak point in insulation and may cause dielectric breakdown. Therefore, it is necessary to accurately know the amount of saturated water dissolved at low and high temperatures in order to estimate the dielectric breakdown voltage of the operating insulating oil.
飽和水分溶解量を調べる方法として、前記恒温槽を用いた直接測定法によるものではなく、絶縁油の特性から推定する方法が知られている。
飽和水分溶解量（Ｗｓ）を温度（Ｔ）のみの関数として推定する計算式をOommenやGriffinは以下の（１）式のように報告している。
As a method for examining the amount of dissolved saturated water, there is known a method of estimating from the characteristics of insulating oil, not by the direct measurement method using the thermostat.
Oommen and Griffin have reported a calculation formula for estimating the saturated water dissolution amount (Ws) as a function of only the temperature (T) as the following formula (1).
ここで、Oommenは、パラメータとしてＡ＝７．４２、Ｂ＝１６７０を与え、Griffinは、パラメータとしてＡ＝７．０９、Ｂ＝１５６７を与えている（非特許文献１、２参照）。（１）式において、パラメータＡは、反応式Ｈ２Ｏ＋Ｈ２Ｏ⇔（Ｈ２Ｏ）２に対する結合反応速度と分解反応速度の比に関係する量を示し、パラメータＢは水の蒸発潜熱と関係する量を示す。
使用後の絶縁油の場合、油は酸化劣化し飽和水分溶解量が増大する。DavidovとRoizmanは、以下の（２）式を報告している。
Here, Oommen gives A = 7.42 and B = 1670 as parameters, and Griffin gives A = 7.09 and B = 1567 as parameters (see Non-Patent Documents 1 and 2). In the equation (1), the parameter A indicates an amount related to the ratio of the binding reaction rate to the decomposition reaction rate with respect to the reaction formula H 2 O + H 2 O⇔ (H 2 O) 2 , and the parameter B is related to the latent heat of evaporation of water. Indicates the amount to do.
In the case of insulating oil after use, the oil is oxidized and deteriorated, and the amount of saturated water dissolved increases. Davidov and Roizman reported the following equation (2).
ここで、DavidovとRoizmanは、新油に対しパラメータとして、Ａ＝１７．０８、Ｂ＝３８７６を与え、使用油に対しパラメータとして、Ａ＝１６．１４、Ｂ＝３４０１を与えている（非特許文献３参照）。
また、Mladenovは推定式に酸価Ａｎと芳香族分（％）Ａｒを用いて以下の（３）式を報告している。酸価Ａｎとは、絶縁油１ｇ中に含まれる全酸性成分を中和するのに要する水酸化カリウムのｍｇ数をいう。
Here, Davidov and Roizman give A = 17.08 and B = 3876 as parameters for the new oil, and A = 16.14 and B = 3401 as parameters for the oil used (non-patent). Reference 3).
Mladenov reports the following formula (3) using the acid value An and the aromatic content (%) Ar as the estimation formula. The acid value An refers to the number of mg of potassium hydroxide required to neutralize all acidic components contained in 1 g of insulating oil.
ここで、Mladenovは、パラメータとして、Ａ＝１６．２８、Ｂ＝３６９８、Ｃ＝０．０２５８９、Ｄ＝２．０９９を与えている（非特許文献４参照）。
（３）式において、パラメータＣは、芳香族分（％）の影響度合いを示す量、パラメータＤは、酸価の影響度合いを示す量、パラメータＣとＤは非特許文献４の記載では実験から求められた値とされている。
Here, Mladenov gives A = 16.28, B = 3698, C = 0.0589, and D = 2.0099 as parameters (see Non-Patent Document 4).
In the equation (3), the parameter C is an amount indicating the degree of influence of the aromatic content (%), the parameter D is an amount indicating the degree of influence of the acid value, and the parameters C and D are experimentally described in
また、以下の特許文献１には、油中水分量に加え、絶縁油中のカルボニル価を測定し、その両者の値から絶縁劣化を診断する方法が提案されている。 Further, Patent Document 1 below proposes a method of diagnosing insulation deterioration from both values by measuring the carbonyl value in insulating oil in addition to the moisture content in oil.
ところが、絶縁油の劣化状態を把握することは従来技術では容易ではなく、酸価と芳香族分を考慮した上述の（３）式で示すMladenovの推定式であっても、計算値は後述するように実測値に対し２０％を超す乖離を生じる場合もある。このため、本発明者は、より正確に飽和水分溶解量を推定し、絶縁油の劣化診断をするためには、上述の推定式の改良が必要であると考えている。 However, it is not easy in the prior art to grasp the deterioration state of the insulating oil, and the calculated value will be described later even if it is the Mladenov estimation formula shown in the above formula (3) considering the acid value and aromatic content. Thus, a deviation exceeding 20% may occur with respect to the actually measured value. For this reason, the present inventor believes that the above estimation formula needs to be improved in order to estimate the saturated water dissolution amount more accurately and to diagnose the deterioration of the insulating oil.
また、特許文献１に記載されている如く、油中水分量に加え、絶縁油中のカルボニル価を測定し、その両者の値から絶縁劣化を診断する方法では、飽和水分溶解量の測定は実測にたよっており、低温および高温における飽和水分溶解量についての記載はなく、低温および高温における絶縁油の絶縁劣化の診断には応用できない問題がある。 In addition, as described in Patent Document 1, in the method of measuring the carbonyl value in insulating oil in addition to the amount of water in oil and diagnosing insulation deterioration from both values, the measurement of the amount of dissolved saturated water is actually measured. Therefore, there is no description about the amount of dissolved saturated water at low and high temperatures, and there is a problem that cannot be applied to the diagnosis of insulation deterioration of insulating oil at low and high temperatures.
従って、本発明の課題は、上記の如き従来の飽和水分溶解量の推定式による絶縁油の劣化度測定方法の開発状況に鑑み、絶縁油をゲル浸透クロマトグラフィー法により分子量測定し、その分子量を用いて酸価と油中水分量の測定結果から、水分飽和度を推定し、この水分飽和度から絶縁油の劣化を診断する方法を提供することを目的とする。
さらに本発明は、正確な飽和水分溶解量を算出できる推定式を提供することにあり、その推定式から得られる値を用いることでより的確な絶縁油の絶縁劣化を診断する方法を提供することを目的とする。
Therefore, in view of the development status of the conventional method for measuring the degree of deterioration of insulating oil based on the equation for estimating saturated water solubility as described above, the object of the present invention is to measure the molecular weight of an insulating oil by gel permeation chromatography and determine the molecular weight. It is an object of the present invention to provide a method for estimating moisture saturation from the measurement results of acid value and moisture content in oil and diagnosing deterioration of insulating oil from the moisture saturation.
Furthermore, the present invention provides an estimation formula that can calculate an accurate saturated water dissolution amount, and provides a more accurate method for diagnosing insulation deterioration of insulating oil by using a value obtained from the estimation formula. With the goal.
前記課題を解決するために本発明者らは、前記絶縁油の劣化度測定方法の開発動向を勘案し、前記課題を解決するために鋭意検討を重ねた結果、飽和水分溶解量の計算においてその絶縁油の正確な分子量を考慮することで、前記従来の推定式よりも正確に飽和水分溶解量を推定する式を提供することができ、この推定式に基づき求めた飽和水分溶解量を考慮することで絶縁油の絶縁劣化を適格に診断できることを知見し本願発明に到達した。 In order to solve the above problems, the present inventors considered the development trend of the method for measuring the degree of deterioration of the insulating oil, and as a result of intensive studies to solve the above problems, the calculation of the saturated water dissolution amount By considering the exact molecular weight of the insulating oil, it is possible to provide an equation for estimating the saturated water dissolution amount more accurately than the conventional estimation equation, and taking into account the saturated water dissolution amount obtained based on this estimation equation Thus, the inventors have found that the insulation deterioration of the insulating oil can be properly diagnosed, and have reached the present invention.
本発明は、電気機器に充填された絶縁油のゲル浸透クロマトグラフィー法による分子量の測定値と、絶縁油１ｇ中に含まれる全酸性成分を中和するのに要する水酸化カリウムのｍｇ数で示される酸価の測定値と、ｍｇ数で示される油中水分の重量を測定し、絶縁油のモル数で除した油中水分量の値と、絶対温度の関数として示す１０（Ａ−Ｂ／Ｔ）で示される算出式（Ａ、Ｂはパラメータ）に、[ｍＫＯＨｍｏｌ／油ｍｏｌ]単位で表した酸価とその影響度合いを乗算して算出した飽和水分溶解量を用い、前記油中水分量を飽和水分溶解量で除した水分飽和度を求め、この水分飽和度が１を超えるか、１に近いほど、絶縁油の劣化が進んでいると判断することを特徴とする電気機器中絶縁油の絶縁劣化診断方法に関する。
The present invention shows the measured value of the molecular weight of the insulating oil filled in the electrical equipment by the gel permeation chromatography method and the number of mg of potassium hydroxide required to neutralize all acidic components contained in 1 g of the insulating oil. and measurement of acid value is to measure the weight of the oil in water represented by mg number, and the value of dividing the oil water content in moles of the insulating oil, expressed as the absolute temperature of the
本発明は、電気機器に充填された絶縁油の酸価増加分と絶縁油の分子量増加分の相関関係から、未使用時の絶縁油の分子量を基に酸化劣化後の分子量を推測し、推測された絶縁油の分子量と、絶縁油１ｇ中に含まれる全酸性成分を中和するのに要する水酸化カリウムのｍｇ数で示される酸価の測定値と、ｍｇ数で示される油中水分の重量を測定し、絶縁油のモル数で除した油中水分量の値と、絶対温度の関数として示す１０（Ａ−Ｂ／Ｔ）で示される算出式（Ａ、Ｂはパラメータ）に、[ｍＫＯＨｍｏｌ／油ｍｏｌ]単位で表した酸価とその影響度合いを乗算して算出した飽和水分溶解量を用い、前記油中水分量を飽和水分溶解量で除した水分飽和度を求め、この水分飽和度が１を超えるか、１に近いほど、絶縁油の劣化が進んでいると判断することを特徴とする電気機器中絶縁油の絶縁劣化診断方法に関する。 The present invention estimates the molecular weight after oxidative degradation based on the molecular weight of the insulating oil when not in use, based on the correlation between the increase in the acid value of the insulating oil filled in the electrical equipment and the increase in the molecular weight of the insulating oil. The measured molecular weight of the insulating oil, the acid value measured in mg of potassium hydroxide required to neutralize all acidic components contained in 1 g of insulating oil, and the moisture content in the oil expressed in mg When the weight is measured and the moisture content in oil divided by the number of moles of insulating oil and the calculation formula (A and B are parameters) represented by 10 ( AB / T) as a function of absolute temperature, mKOHmol / oil mol] Using the saturated water dissolution amount calculated by multiplying the acid value expressed in units of the acid value and the degree of influence thereof, the water saturation obtained by dividing the water content in the oil by the saturated water dissolution amount was obtained, and this water saturation It is judged that the deterioration of the insulating oil is advanced as the degree exceeds 1 or is close to 1. It relates insulation degradation diagnosis method of an electric device in insulating oil, characterized in that.
本発明は、カールフィッシャー法により油中水分量を測定し、この測定される油中水分量を溶解水と油中活性点への吸着水の和と仮定し、酸価の測定により消費されるＫＯＨ量は絶縁油分子の活性点の数と等しいと仮定し、活性点への飽和吸着水量は飽和溶解水量に比例し、温度変化に対し飽和溶解水量が増加し、吸着水の温度依存性が生じると仮定し、飽和水分溶解量を絶対温度の関数として示す１０（Ａ−Ｂ／Ｔ）で示される算出式に比例定数と[ｍＫＯＨｍｏｌ／油ｍｏｌ]単位で表した酸価を乗算して飽和水分溶解量を算出することを特徴とする電気機器中絶縁油の絶縁劣化診断方法に関する。 In the present invention, the water content in oil is measured by the Karl Fischer method, and the water content in the measured oil is assumed to be the sum of dissolved water and water adsorbed to the active point in the oil, and is consumed by measuring the acid value. Assuming that the amount of KOH is equal to the number of active points of the insulating oil molecule, the amount of saturated adsorbed water at the active point is proportional to the amount of saturated dissolved water, the amount of saturated dissolved water increases with temperature change, and the temperature dependence of adsorbed water is Assuming that this occurs, saturation is obtained by multiplying the calculation formula represented by 10 ( AB / T), which shows the saturated water solubility as a function of absolute temperature, by the proportionality constant and the acid value expressed in [mKOH mol / mol mol]. The present invention relates to a method for diagnosing insulation deterioration of insulating oil in electrical equipment, wherein the amount of water dissolved is calculated.
前記飽和水分溶解量（Ｗｓ[mg/mol]）の値として、Ｗｓ[mg/mol]＝（１＋Ｃ×Ａｎ’）１０（Ａ−Ｂ／Ｔ）で示す推定式を用いることを特徴とする先に記載の絶縁劣化診断方法。
ただし、前記推定式において、パラメータＣは酸価の影響度合いを示す量、Ａｎ’は[ｍ ＫＯＨ ｍｏｌ／油 ｍｏｌ]単位で表した酸価を表し、パラメータＡは、反応式Ｈ２Ｏ＋Ｈ２Ｏ⇔（Ｈ２Ｏ）２に対する結合反応速度と分解反応速度の比に関係する量、パラメータＢは水の蒸発潜熱に関係する量、Ｔは絶対温度を示す。
As the value of the saturated water dissolution amount (Ws [mg / mol] ) , an estimation formula represented by Ws [mg / mol] = (1 + C × An ′) 10 (A−B / T) is used. The insulation deterioration diagnosis method described in 1.
In the above estimation formula, parameter C is an amount indicating the degree of influence of the acid value, An ′ is an acid value expressed in units of [m KOH mol / oil mol], and parameter A is a reaction formula H 2 O + H 2 O. An amount related to the ratio of the binding reaction rate to the decomposition reaction rate for ⇔ (H 2 O) 2 , parameter B is an amount related to the latent heat of vaporization of water, and T is an absolute temperature.
本発明において、前記パラメータＡを６．５２４、前記パラメータＢを１５６７、前記パラメータＣを０．００８９とすることができる。
本発明において、前記水分飽和度と絶縁油の絶縁破壊電圧との関係を予め求めておき、絶縁油が用いられる電気機器に必要な耐圧を、前記絶縁破壊電圧との関係で求めて絶縁油の適正を判断することができる。
In the present invention, the parameter A may be 6.524, the parameter B may be 1567, and the parameter C may be 0.0089.
In the present invention, the relationship between the moisture saturation and the dielectric breakdown voltage of the insulating oil is determined in advance, and the withstand voltage required for the electrical equipment in which the insulating oil is used is determined based on the relationship with the dielectric breakdown voltage. Appropriateness can be judged.
本発明によれば、ゲル浸透クロマトグラフィー法による正確な絶縁油の分子量の測定を行い、油中水分の重量を絶縁油のモル数で除した油中水分量を飽和水分溶解量で除した水分飽和度を求め、この水分飽和度の値が１を超えるか、１に近いか否かによって絶縁油の絶縁劣化を見極めることができる。
また、本発明によれば、酸価を尺度として酸価増加分と分子量増加分を求め、未使用時の絶縁油の分子量を基に酸化劣化後の分子量を推測し、この推測された分子量を基に、油中水分の重量を絶縁油のモル数で除した油中水分量を飽和水分溶解量で除した水分飽和度を求め、この水分飽和度の値が１を超えるか、１に近いか否かによって絶縁油の絶縁劣化を見極めることができる。
According to the present invention, the molecular weight of an insulating oil is accurately measured by a gel permeation chromatography method, and the water content obtained by dividing the weight of water in the oil by the number of moles of insulating oil is divided by the saturated water solubility. It is possible to determine the degree of saturation and determine the insulation deterioration of the insulating oil depending on whether the value of the water saturation exceeds 1 or is close to 1.
Further, according to the present invention, the acid value increment and the molecular weight increase are obtained on the basis of the acid value, the molecular weight after oxidative degradation is estimated based on the molecular weight of the insulating oil when not in use, and the estimated molecular weight is calculated. Based on this, the water saturation obtained by dividing the weight of water in oil by the number of moles of insulating oil and dividing the amount of water in oil by the amount of saturated water dissolved is obtained, and the value of this water saturation exceeds 1 or is close to 1. It is possible to determine the insulation deterioration of the insulating oil depending on whether or not.
本発明によれば、油の分子量を考慮し、従来よりも改良した推定式で飽和水分溶解量を求め、油中水分量を飽和水分溶解量推定値で除して水分飽和度を求め、正確な水分飽和度を用いることにより、正確な絶縁油の絶縁劣化診断を実施できる。
飽和水分溶解量を従来よりも正確に見積もりできる結果、油の劣化をより正確に診断することができるので、適切な時期に油から水分を除去するか、油を交換するなどの対策がとれ、電気機器を適切に運転管理することで、電気機器運転の信頼性を向上できる効果がある。
According to the present invention, taking into account the molecular weight of the oil, the saturated water dissolution amount is obtained by an estimation formula improved from the conventional method, and the water saturation is obtained by dividing the water content in the oil by the saturated water solubility estimation value. By using a proper water saturation, an accurate insulation deterioration diagnosis of insulating oil can be performed.
As a result of being able to estimate the saturated water dissolution amount more accurately than before, the deterioration of the oil can be diagnosed more accurately, so measures such as removing water from the oil or replacing the oil at an appropriate time can be taken, By appropriately managing the operation of the electrical equipment, there is an effect that the reliability of the electrical equipment operation can be improved.
＜第１実施形態＞
以下、本発明に係る絶縁油の絶縁劣化診断方法の実施形態について図面に基づき説明する。
本発明者らの種々研究の結果、絶縁油の分子量を考慮すると絶縁油の飽和水分溶解量は酸価の増大に従い大きくなる点を知見し、この知見に基づいて本発明の完成に到達した。
図1は、本発明に係る絶縁油の絶縁劣化を診断する場合の一例のフロー図である。
まず、ステップＳ１において測定対象の絶縁油を電気機器から採取し、ステップＳ２において採取した絶縁油の分子量を測定し、酸価を測定する。それらの値を用い、以下に説明する計算式を用いステップＳ３において飽和水分溶解量の計算を行う。また、別途、ステップＳ４において前記絶縁油の油中水分量測定を行い、ステップＳ５において、先に求めた飽和水分溶解量の計算結果を利用し、油中水分量を飽和水分溶解量で除して水分飽和度を求める。そして、この水分飽和度の計算結果を基に電気機器から採取した絶縁油の絶縁劣化診断をステップＳ６で行うことができる。
酸価の測定は、例えば、ＪＩＳ Ｃ２１０１「電気絶縁油試験方法」に準拠して測定することができる。
<First Embodiment>
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an insulation oil insulation deterioration diagnosis method according to the present invention will be described below with reference to the drawings.
As a result of various studies by the present inventors, it has been found that the saturated water dissolution amount of the insulating oil increases as the acid value increases in consideration of the molecular weight of the insulating oil, and the present invention has been completed based on this finding.
FIG. 1 is a flowchart of an example when diagnosing insulation deterioration of insulating oil according to the present invention.
First, in step S1, the insulating oil to be measured is collected from the electric device, the molecular weight of the insulating oil collected in step S2 is measured, and the acid value is measured. Using these values, the saturated water dissolution amount is calculated in step S3 using the calculation formula described below. Separately, the moisture content in the oil of the insulating oil is measured in step S4. In step S5, the water content in the oil is divided by the saturated moisture content, using the calculation result of the saturated moisture content obtained previously. To determine the water saturation. And the insulation deterioration diagnosis of the insulation oil extract | collected from the electric equipment based on the calculation result of this moisture saturation can be performed by step S6.
The acid value can be measured, for example, according to JIS C2101 “Electrical insulating oil test method”.
次に、ステップＳ３において用いる飽和水分溶解量の算出式について説明する。
これまで、油を用いた工業の分野では油中水分量は油中水分の重量［ｍｇ］を油の重量［ｋｇ］で除した［ｐｐｍ］を単位として捉えてきた。
しかし、本発明者らは油分子の分子量（Ｍ）に着目し、油中水分量について水重量［ｍｇ］を油のモル数で除した［ｍｇ／ｍｏｌ］を単位として捉えなおし、油中水分を温度と酸価で整理したのちに再び［ｐｐｍ］で表示すると、上述の従来報告されてきた推定式よりもより正確に水分飽和度を推定する式を立案できると判断し、水分飽和度の推定式を以下の（４）式のように得た。
Next, a calculation formula for the saturated water dissolution amount used in step S3 will be described.
Until now, in the industrial field using oil, the amount of water in oil has been taken as a unit of [ppm] obtained by dividing the weight of water in oil [mg] by the weight of oil [kg].
However, the present inventors pay attention to the molecular weight (M) of the oil molecule, and re-recognize the water weight [mg] by dividing the water weight [mg] by the number of moles of oil as the unit, and the moisture in the oil. If the results are sorted in terms of temperature and acid value and then displayed in [ppm] again, it is determined that a formula for estimating the water saturation can be formulated more accurately than the previously reported estimation formula. The estimation formula was obtained as the following formula (4).
この（４）式において、Ａ＝６．５２４、Ｂ＝１５６７、Ｃ＝０．００８９とすることができる。（４）式において、数字の１０あとに記載されたべき乗を示す演算子を＾で記載すると、（４）式は、Ｗｓ[ｐｐｍ]＝１０００・１０＾（Ａ−Ｂ／Ｔ）・（１＋Ｃ・Ａｎ・Ｍ）／Ｍと表記することができる。
この（４）式で示す推定式を用いると、計算値と実験値との差を後述する実施例に示されるように１０％程度以下に改善できる。
（４）式において、パラメータＡの値は使用する絶縁油の成分により水分子の移動速度や水分子同士が出会う確率が変化する可能性があり、若干異なることが考えられる。
パラメータＢの値は水分同士が純粋な形で結合する場合は一定と考えられるが、絶縁油中のイオンやその他の不純物により若干の影響があり得ると考えられる。
しかし、（４）式でパラメータＢは、前述のGriffinの値を使用することができると本発明者は判断した。これは、ＩＥＣ（International Electrotechnical Commission）の規格（ＩＥＣ６０４２２）に記載されていて、この値を採用することが本発明で想定する絶縁油の場合に適用できると考えられる。
（４）式のパラメータＡは、ＢをGriffinの値としたうえで、絶縁油の油温３５℃のデータにて酸価を０と外挿して決定できる。例えば、後述する図８に示す飽和水分溶解度（３５℃）と酸価の相関関係を示すグラフから、ｙ切片（酸価０の時の飽和水分溶解量の値≒２７）を求め、（４）式に各値を代入すると、パラメータＡを逆算できるので、この逆算値を適用する。
In the formula (4), A = 6.524, B = 1567, and C = 0.895. In the expression (4), when an operator indicating a power that is described after the
When the estimation formula shown by the formula (4) is used, the difference between the calculated value and the experimental value can be improved to about 10% or less as shown in an example described later.
In the equation (4), the value of the parameter A may vary slightly depending on the component of the insulating oil to be used because the moving speed of water molecules and the probability that water molecules meet each other may change.
The value of parameter B is considered to be constant when moisture is bound in a pure form, but it is thought that there may be some influence due to ions and other impurities in the insulating oil.
However, the present inventor has determined that the above-described Griffin value can be used as the parameter B in the equation (4). This is described in the IEC (International Electrotechnical Commission) standard (IEC60422), and it is considered that this value can be applied to the case of the insulating oil assumed in the present invention.
The parameter A in the equation (4) can be determined by extrapolating the acid value as 0 based on the data of the oil temperature of 35 ° C. of the insulating oil after setting B as the value of Griffin. For example, from the graph showing the correlation between the saturated water solubility (35 ° C.) and the acid value shown in FIG. 8 to be described later, the y-intercept (the value of the saturated water solubility when the acid value is 0≈27) is obtained, (4) By substituting each value into the equation, the parameter A can be calculated in reverse, so this calculated value is applied.
次に、（１）式〜（４）式について、パラメータＡ、Ｂの対比説明を行う。
（１）式〜（４）式では常用対数と自然対数をそれぞれ使い分けているが、以下の表１に常用対数と自然対数をお互い変換して対照した値を示す。自然対数の係数は常用対数の２．３倍（＝log１０倍）であるので、以下の表１に示す関係となる。なお、表１において、Davidov & Roizman（Davidov & R．）の文献に記載されている数値については新油の方の係数を示している。
Next, the comparison between the parameters A and B will be described with respect to the expressions (1) to (4).
In the formulas (1) to (4), the common logarithm and the natural logarithm are separately used. Table 1 below shows values obtained by converting the common logarithm and the natural logarithm to each other. Since the natural logarithm coefficient is 2.3 times the common logarithm (= log 10 times), the relationship shown in Table 1 below is obtained. In Table 1, for the numerical values described in the literature of Davidov & Roizman (Davidov & R.), the coefficients of the new oil are shown.
水分飽和度が（４）式の様に与えられるのは、一般に化学の分野では物質の溶解量を取り扱う際、物質量をｍｏｌ単位で表す。すなわち、油分子と水分子の関係はｍｏｌ単位同士で捉えられるべき量であると考えられるからである。
化学の分野では溶解量を［ｍｏｌ／Ｌ］または［ｍｏｌ／ｋｇ］で表すことが多い。それは化学変化の前後で溶媒の分子量に変化がない場合を想定している。しかし、絶縁油は酸化劣化すると油分子が切れたり、油分子同士が結合したりすることにより、絶縁油の分子量に変化が生じると考えられる。よって油中水分量は［ｍｏｌ／ｍｏｌ］といった単位で捉えるべきであると本発明者らは考えた。ここで単位に現れる分子のｍｏｌは水分量、分母のｍｏｌは絶縁油量を表す。ただし、水分子は１ｍｏｌの重量が１８ｇと決まっているので、分子のｍｏｌはｍｇで表すことが可能で、油中水分量は［ｍｇ／ｍｏｌ］といった単位にすることができる。
なお、（４）式には（３）式に含まれていた芳香族分（％）Ａｒが関与する項がない。本発明者の検討したところによると、芳香族分の関与は分子量（Ｍ）を考慮することで足りることを知見しており、（４）式においては芳香族分の測定は不要となる。
The reason why the water saturation is given as in the formula (4) is that the amount of substance is expressed in mol unit when the dissolved amount of the substance is generally handled in the chemical field. That is, the relationship between oil molecules and water molecules is considered to be an amount that should be captured in mol units.
In the chemical field, the dissolved amount is often expressed by [mol / L] or [mol / kg]. It is assumed that there is no change in the molecular weight of the solvent before and after the chemical change. However, it is considered that when the insulating oil is oxidized and deteriorated, the oil molecules are cut or the oil molecules are bonded to each other, so that the molecular weight of the insulating oil is changed. Therefore, the present inventors considered that the water content in oil should be taken in units of [mol / mol]. Here, the mol of the molecule appearing in the unit represents the amount of water, and the mol of the denominator represents the amount of insulating oil. However, since the weight of 1 mol of water molecules is determined to be 18 g, the mol of molecules can be expressed in mg, and the amount of water in oil can be in units of [mg / mol].
The formula (4) does not include a term related to the aromatic component (%) Ar contained in the formula (3). According to the study of the present inventor, it has been found that the aromatic content is sufficient considering the molecular weight (M), and in the formula (4), the measurement of the aromatic content becomes unnecessary.
ここで、絶縁油の分子量の決め方が問題になる。油分子には種々の成分があり、油の分子量としてどのような量を指標とするかで測定の仕方が変わる。本発明者の検討したところによると、ゲル浸透クロマトグラフィー（ＧＰＣ）法により求めた重量平均分子量を用いることが適切であると判断した。
ＧＰＣ法は、分子サイズに基づいて分離分析する手法であり、分子量既知の物質で作成した検量線から試料の分子量を求める方法として知られている。本実施形態では、分子量既知の分子量標準試薬として鎖状炭化水素（ｎ−ヘキサン、ｎ−ノナン、ｎ−ドデカン、ｎ−ヘキサデカン）および環状炭化水素（ナフタレン、アントラセン、ナフタレン）などを用いることができる。
Here, how to determine the molecular weight of the insulating oil becomes a problem. There are various components in oil molecules, and the measurement method varies depending on what amount is used as an index of the molecular weight of oil. According to the study of the present inventors, it was determined that it is appropriate to use the weight average molecular weight determined by gel permeation chromatography (GPC) method.
The GPC method is a technique for performing separation analysis based on the molecular size, and is known as a method for obtaining the molecular weight of a sample from a calibration curve created with a substance having a known molecular weight. In the present embodiment, chain hydrocarbons (n-hexane, n-nonane, n-dodecane, n-hexadecane), cyclic hydrocarbons (naphthalene, anthracene, naphthalene) and the like can be used as molecular weight standard reagents with known molecular weights. .
ＧＰＣ法として、微細孔を数多く存在する充填剤粒子を収容したカラムを用い、当該カラムに被測定対象の絶縁油を流すと、小さい溶質分子は充填剤の微細孔の奥まで浸透しながら遅く流れ、大きい溶質分子は微細孔に入らずに充填剤粒子の境界を通過して早く流れるので、分子サイズに応じて篩い分けができる。分子量既知の標準試料の溶質成分を吸光度検出器、示差屈折検出器、ＵＶ検出器、フォトダイオードアレイ検出器などのいずれかの検出器を用いて通過した溶質から得られる信号強度の各ピークのピークトップの溶出時間と分子量から検量線を作成することができる。
次に、被測定対象の絶縁油をカラムに通し、各溶出位置における信号強度から試料濃度を求め、先の検量線から絶縁油の分子量（相対分子量）を求めることで絶縁油の分子量を測定することができる。
As a GPC method, using a column containing filler particles with many fine pores and flowing the insulating oil to be measured through the column, small solute molecules flow slowly while penetrating deep into the fine pores of the filler. Large solute molecules flow quickly through the boundaries of the filler particles without entering the micropores, and can be sieved according to the molecular size. Peak of each peak of signal intensity obtained from solute that passed through solute component of standard sample with known molecular weight using any detector such as absorbance detector, differential refraction detector, UV detector, photodiode array detector, etc. A calibration curve can be created from the top elution time and molecular weight.
Next, the insulating oil to be measured is passed through the column, the sample concentration is obtained from the signal intensity at each elution position, and the molecular weight (relative molecular weight) of the insulating oil is obtained from the previous calibration curve to measure the molecular weight of the insulating oil. be able to.
一例として、上述のｎ−ヘキサデカン（分子量２２６．４４ｇ／ｍｏｌ、溶出時間１５．５９分）、ｎ−ドデカン（分子量１７０．３３ｇ／ｍｏｌ、溶出時間１６．４４分）、ｎ−ノナン（分子量１２８．２６ｇ／ｍｏｌ、溶出時間１７．２４分）、ｎ−ヘキサン（分子量８６．１８ｇ／ｍｏｌ、溶出時間１８．３８分）を例示できる。更に、ナフタセン（分子量２２８．２９ｇ／ｍｏｌ、溶出時間１７．９０分）、アントラセン（分子量１７８．２３ｇ／ｍｏｌ、溶出時間１８．７４分）、ナフタレン（分子量１２８．１８ｇ／ｍｏｌ、溶出時間１８．７４分）を例示できる。 As an example, the above-mentioned n-hexadecane (molecular weight: 226.44 g / mol, elution time: 15.59 minutes), n-dodecane (molecular weight: 170.33 g / mol, elution time: 16.44 minutes), n-nonane (molecular weight: 128. Examples thereof include 26 g / mol, elution time 17.24 minutes), and n-hexane (molecular weight 86.18 g / mol, elution time 18.38 minutes). Furthermore, naphthacene (molecular weight 228.29 g / mol, elution time 17.90 minutes), anthracene (molecular weight 178.23 g / mol, elution time 18.74 minutes), naphthalene (molecular weight 128.18 g / mol, elution time 18.74). Min).
ＧＰＣ法では分子サイズが大きいほどカラムから速く溶出する。分子サイズは分子構造に影響されるため、同一分子量であっても分子サイズが異なれば溶出時間には差が生じる。実際にｎ−ヘキサデカンとナフタセン、ｎ−ノナンとナフタレンは分子量がほぼ同一であるが、溶出時間には約２分の差が生じる。同一分子サイズの絶縁油を考えた時、パラフィン鎖の分岐が多い、あるいは環状構造になるほど分子量が大きくなる。つまり、分子構造の溶出時間への影響は、同一分子量の場合、分岐が多いあるいは環状構造になるほど分子サイズが小さくなり、溶出時間が遅くなると考えられる。 In the GPC method, the larger the molecular size, the faster the column elutes. Since the molecular size is affected by the molecular structure, even if the molecular weight is the same, the elution time differs if the molecular size is different. Actually, n-hexadecane and naphthacene, n-nonane and naphthalene have almost the same molecular weight, but the elution time differs by about 2 minutes. When insulating oils of the same molecular size are considered, the molecular weight increases as the number of paraffin chains increases or the structure becomes cyclic. That is, the influence of the molecular structure on the elution time is considered to be that the molecular size becomes smaller and the elution time becomes slower as the molecular weight becomes the same, as the number of branches or the cyclic structure increases.
絶縁油は鎖状炭化水素と環状炭化水素の混合物であるため、検量線は鎖状炭化水素と環状炭化水素の間になると予想される。ただし、絶縁油中の鎖状炭化水素は多くの分岐を持つため、分子サイズは小さくなる。つまり、絶縁油の検量線は環状炭化水素に近づくと考えられる。したがって、環状炭化水素の検量線が絶縁油の分子量を良く表すと考え、分子量の計算には環状炭化水素による検量線を用いる。なお、ＧＰＣ法によって得られる分子量には数平均分子量、重量平均分子量、Ｚ平均分子量等があるが、本実施形態では重量平均分子量で表すこととする。 Since the insulating oil is a mixture of chain and cyclic hydrocarbons, the calibration curve is expected to be between the chain and cyclic hydrocarbons. However, since the chain hydrocarbon in the insulating oil has many branches, the molecular size becomes small. That is, it is considered that the calibration curve for insulating oil approaches a cyclic hydrocarbon. Therefore, it is considered that the calibration curve for the cyclic hydrocarbon represents the molecular weight of the insulating oil, and the calibration curve for the cyclic hydrocarbon is used for the calculation of the molecular weight. The molecular weight obtained by the GPC method includes a number average molecular weight, a weight average molecular weight, and a Z average molecular weight. In the present embodiment, the molecular weight is represented by a weight average molecular weight.
以下に、前記（４）式に示す飽和水分溶解量の推定式を確立した考え方について再度説明する。
絶縁油中飽和水分溶解量の測定には、図３に示す器具を用い、平衡状態を得る。図３において、収容器（デシケーター）１には水２の入った容器（ビーカー）３と絶縁油４の入った容器（ビーカー）５が収容されており、１気圧で十分に時間をかけ静置して温度Ｔ［Ｋ］＝ｔ［℃］＋２７３．１５で平衡状態とする。
デシケータ１内の空気の水蒸気圧は温度ｔ［℃］における飽和水蒸気圧Ｅ（ｔ）となる。
Ｅ（ｔ）はＴｅｔｅｎｓ（１９３０）の実験式として以下の（５）式が知られている。
Below, the idea which established the estimation formula of the saturated water | moisture-content dissolution amount shown to said (4) Formula is demonstrated again.
The instrument shown in FIG. 3 is used to measure the amount of saturated water dissolved in the insulating oil, and an equilibrium state is obtained. In FIG. 3, a container (desicator) 1 contains a container (beaker) 3 containing
The water vapor pressure of the air in the desiccator 1 becomes the saturated water vapor pressure E (t) at the temperature t [° C.].
As E (t), the following formula (5) is known as an empirical formula of Tetens (1930).
（たとえば、３５℃では５６．２４ｈＰａ＝３９．６０ｇ／ｍ３）
一般に、化合物の蒸気圧と測定温度の間の関係はアントワン式（Ａｎｔｏｉｎｅ式）と呼ばれ、以下の（６）式で表される。ここで、Ｐは蒸気圧、Ａ、Ｂ、Ｃは定数である。
(For example, at 35 ° C., 56.24 hPa = 39.60 g / m 3 )
In general, the relationship between the vapor pressure of a compound and the measurement temperature is called the Antoine equation (Antoine equation) and is expressed by the following equation (6). Here, P is a vapor pressure, and A, B, and C are constants.
このとき、絶縁油中水分蒸気圧は収容器（デシケータ）１内の空気の水蒸気圧Ｅ（ｔ）と等しい。
温度ｔにおける飽和溶解水量は、このときの油中水分蒸気圧と比例していることから、飽和溶解水量は（６）式に比例した形式で表されると考えられる。
ここでＣを２７３．１５と近似し、油中飽和溶解水量をＷｄｓと表すと以下の（７）式の関係式が得られる。
At this time, the water vapor pressure in the insulating oil is equal to the water vapor pressure E (t) of the air in the container (desiccator) 1.
Since the amount of saturated dissolved water at the temperature t is proportional to the water vapor pressure in oil at this time, the amount of saturated dissolved water is considered to be expressed in a form proportional to the equation (6).
Here, when C is approximated to 273.15 and the saturated dissolved water amount in oil is expressed as Wds, the following relational expression (7) is obtained.
溶解水の飽和量は（７）式の形式で表せ、代表的な式はGriffinの式であり、定数Ａ、Ｂは、Ａ＝７．０９、Ｂ＝１５６７で与えられる。 The saturation amount of dissolved water can be expressed in the form of equation (7), a typical equation is Griffin's equation, and constants A and B are given by A = 7.09 and B = 1567.
蒸気圧について基礎になる式はクラウジウス・クライペイロン(Clausius‐Clapeyron)式である。 The underlying equation for vapor pressure is the Clausius-Clapeyron equation.
（８）式においてＰは、温度Ｔでの蒸気圧、ΔｖａｐＨは１ ｍｏｌ当たりの蒸発エンタルピー変化である。この（８）式は蒸発エンタルピーが温度に依存しないと仮定すると、つぎの（９）式のように積分できる。 In the equation (8), P is the vapor pressure at the temperature T, and Δ vap H is the change in evaporation enthalpy per mol. Assuming that the evaporation enthalpy does not depend on the temperature, the equation (8) can be integrated as the following equation (9).
（９）式において、Ｐ＊は温度Ｔ＊における蒸気圧である。よって、パラメータＢは水の蒸発潜熱と関係する。
絶縁油中で水分子が運動して水分子同士が出会うと水分子は結合する。すると、ある確率で水分子は分離して油分子中に再び拡散する。しかし、水分子結合が分離する前に別な水分子と出会うとその水分子も一緒に結合する。水分子が次々に結合して大きな水分子の集団を形成し、もはや再び油分子の中に拡散しなくなった状態が相分離である。よって、相分離せずに絶縁油中に水分子が溶け込む最大量は、水の結合反応と分解反応が平衡になる量である。水分子の結合反応は、以下の（１０）式で表すことができる。
In the formula (9), P * is the vapor pressure at the temperature T *. Thus, parameter B is related to the latent heat of vaporization of water.
When water molecules move in insulating oil and water molecules meet each other, the water molecules are combined. Then, with some probability, water molecules separate and diffuse again into the oil molecules. However, if another water molecule is encountered before the water molecule bond separates, the water molecule also binds together. Phase separation is a state in which water molecules bind to each other to form a large group of water molecules and no longer diffuse into oil molecules again. Therefore, the maximum amount of water molecules dissolved in the insulating oil without phase separation is an amount that equilibrates the water binding reaction and the decomposition reaction. The water molecule binding reaction can be represented by the following formula (10).
と表せる。（１０）式においてｋは結合反応の速度係数であり、以下の（１１）式の関係となる。 It can be expressed. In the equation (10), k is a rate coefficient of the binding reaction, and has the relationship of the following equation (11).
（１２）式において、ｋ’は分解反応の速度係数で、以下の（１３）式で表すことができる。 In the equation (12), k ′ is a decomposition reaction rate coefficient and can be represented by the following equation (13).
結合反応と分解反応が平衡である場合、（１１）式と（１３）式から、
ｋ[Ｈ２Ｏ]２＝ｋ’[（Ｈ２Ｏ）２]の関係があるので、以下の（１４）式が得られる。
When the binding reaction and the decomposition reaction are in equilibrium, from the equations (11) and (13),
Since there is a relationship of k [H 2 O] 2 = k ′ [(H 2 O) 2 ], the following equation (14) is obtained.
（１４）式の意味するところは、溶解する水分子の量、すなわち分離した水分子の濃度が大きくなるのは速度係数の比で決まるということである。要するに、結合反応速度より分解反応速度が速いほど飽和溶解水量が大きくなる。パラメータＡはその様な結合反応速度と分解反応速度の比に関係する量である。 The meaning of equation (14) is that the amount of dissolved water molecules, that is, the concentration of separated water molecules increases, is determined by the ratio of rate coefficients. In short, the amount of saturated dissolved water increases as the decomposition reaction rate is faster than the binding reaction rate. Parameter A is an amount related to the ratio of such binding reaction rate to decomposition reaction rate.
次に、絶縁油が酸化劣化して酸価がＡｎ［ｍｇＫＯＨ／ｇ］となった場合の飽和水分溶解量を考える。
これまで、油を用いた工業の分野では油中水分量は油中水分の重量［ｍｇ］を油の重量［ｋｇ］で除した［ｐｐｍ］を単位として捉えてきた。しかし、本発明者らは油分子の分子量（Ｍ）に着目し、油中水分量について水重量［ｍｇ］を油のモル数で除した［ｍｇ／ｍｏｌ］を単位として捉えなおすことが有効ではないかと考えた。
一般に化学の分野では物質の溶解量を取り扱う際、物質量をｍｏｌ単位で表す。すなわち、油分子と水分子の関係はｍｏｌ単位同士で捉えられるべき量であると考えられるからである。化学の分野では溶解量を［ｍｏｌ／Ｌ］または［ｍｏｌ／ｋｇ］で表すことが多い。それは化学変化の前後で溶媒の分子量に変化がない場合を想定している。しかし、絶縁油は酸化劣化すると油分子が切れたり、油分子同士が結合したりすることにより、絶縁油の分子量に変化が生じる。よって油中水分量は［ｍｏｌ／ｍｏｌ］といった単位で捉えるべきであると考えた。ここで単位に現れる分子のｍｏｌは水分量、分母のｍｏｌは絶縁油量を表す。ただし、水分子は１ｍｏｌの重量が１８ｇと決まっているので、分子のｍｏｌはｍｇで表すことが可能で、油中水分量は［ｍｇ／ｍｏｌ］といった単位にすることができる。絶縁油に溶解している水分量をここからは油１ｍｏｌ当たりのｍｇ数で表すことにする。
Next, the saturated water dissolution amount when the insulating oil is oxidized and deteriorated and the acid value becomes An [mg KOH / g] will be considered.
Until now, in the industrial field using oil, the amount of water in oil has been taken as a unit of [ppm] obtained by dividing the weight of water in oil [mg] by the weight of oil [kg]. However, the present inventors pay attention to the molecular weight (M) of the oil molecule, and it is effective to re-recognize the unit [mg / mol] obtained by dividing the water weight [mg] by the number of moles of oil with respect to the amount of water in the oil. I thought.
Generally, in the field of chemistry, when handling the dissolved amount of a substance, the amount of the substance is expressed in mol units. That is, the relationship between oil molecules and water molecules is considered to be an amount that should be captured in mol units. In the chemical field, the dissolved amount is often expressed by [mol / L] or [mol / kg]. It is assumed that there is no change in the molecular weight of the solvent before and after the chemical change. However, when the insulating oil is oxidized and deteriorated, the oil molecules are cut or the oil molecules are bonded to each other, so that the molecular weight of the insulating oil is changed. Therefore, it was considered that the water content in oil should be captured in units such as [mol / mol]. Here, the mol of the molecule appearing in the unit represents the amount of water and the mol of the denominator represents the amount of insulating oil. However, since the weight of 1 mol of water molecules is determined to be 18 g, the mol of molecules can be expressed in mg, and the amount of water in oil can be in units of [mg / mol]. Here, the amount of water dissolved in the insulating oil is expressed in mg per mol of oil.
ここで、「溶解限界(solubity limit)」と「水飽和限界(water saturation)」を定義する必要がある。その定義の詳細は次の文献に記載されている。
V. G. Arakelian and I. Fofana, “Water in Oil-Filled High-Voltage Equipment Part I: States, Solubility, and Equilibrium in Insulating Materials”, IEEE Electr. Insul. Mag., vol.23, No.4, pp. 15-27, 2007.
「溶解限界」あるいは簡単には「溶解度(solubility)」は、その温度の飽和条件下で媒体(油)中に存在する成分(水)の最大含有量であり、ヘンリーの法則に従う。それに対し、「水飽和限界」は物理的または化学的に結合している吸着水も含む。そしてカールフィッシャー法で測定される油中水分量(Ｗ[ｍｇ／ｍｏｌ])は、溶解水(Ｗｄ[ｍｇ／ｍｏｌ])と活性点への吸着水(Ｗａ[ｍｇ／ｍｏｌ])の和と考える。
Here, it is necessary to define a “solubity limit” and a “water saturation limit”. The details of the definition are described in the following document.
VG Arakelian and I. Fofana, “Water in Oil-Filled High-Voltage Equipment Part I: States, Solubility, and Equilibrium in Insulating Materials”, IEEE Electr. Insul. Mag., Vol.23, No.4, pp. 15 -27, 2007.
“Solubility limit” or simply “solubility” is the maximum content of a component (water) present in a medium (oil) under saturation conditions at that temperature and follows Henry's law. In contrast, “water saturation limit” includes adsorbed water that is physically or chemically bound. The water content in oil (W [mg / mol]) measured by the Karl Fischer method is the sum of dissolved water (Wd [mg / mol]) and water adsorbed to the active site (Wa [mg / mol]). Think.
酸価の測定により消費されるＫＯＨ量は油分子の活性点の数とおよそ等しい。そこで、活性点の数ａは分子量Ｍを用いてＡｎ[ｍｇＫＯＨ／ｇ油]×Ｍ（油）／Ｍ（ＫＯＨ）と計算でき、Ａｎ’ [ｍ ｍｏｌ ＫＯＨ／ｍｏｌ]と表すことにする。
本発明者が実験結果を検討した結果、活性点への飽和吸着水量は（７）式で表される飽和溶解水量Ｗｄｓに比例することがわかった 。
The amount of KOH consumed by measuring the acid value is approximately equal to the number of active sites of the oil molecule. Therefore, the number of active sites a can be calculated as An [mg KOH / g oil] × M (oil) / M (KOH) using the molecular weight M, and is expressed as An ′ [m mol KOH / mol].
As a result of examination of the experimental results by the present inventor, it was found that the amount of saturated adsorbed water at the active site is proportional to the amount of saturated dissolved water Wds expressed by the equation (7).
よって、合計の飽和水分溶解量（Ｗｓ）は、以下の（１５）式で示される。
パラメータＢは、前述のGriffinの式の値１５６７を用いることができる。
パラメータＡは、実験結果をプロットして酸価０の値から６．５２４を用いることができる。
パラメータＣは、後述する実験結果を最適化し、０．００８９を用いることができる。
Therefore, the total saturated water dissolution amount (Ws) is expressed by the following equation (15).
As the parameter B, the value 1567 of the above-described Griffin equation can be used.
As the parameter A, the experimental result can be plotted and 6.524 can be used from the value of 0 acid value.
The parameter C can be set to 0.0089 by optimizing experimental results described later.
次に、後述する実験結果から得られる飽和水分溶解量と酸価の関係について詳細を述べる。後述する飽和吸着水量に関して実験結果は次の通りであった。
・水分吸着量は酸価に比例した。すなわち活性点の数に比例した。
・３０〜３５℃の低温で水分吸着量は活性点の数以下になる。すなわち、水分子は活性点に優先的に吸着するものではない。
・温度が高い場合に活性点には１つ以上の水分子を吸着した。Langmuir型の吸着において吸着は、吸着点の数で制限され、吸着点がすべて水分子で埋め尽くされると、それ以上の水分吸着は起きず、水分吸着量は飽和する。よって、活性点への水分吸着の様子はLangmuir型の吸着とは異なることがわかった。
・飽和吸着水量の温度依存性は飽和溶解水量の温度依存性に近いことがわかった。よって、温度変化に対し飽和溶解水量が増加し、その濃度に比例して吸着することにより、吸着水の温度依存性が生じると考えられる。
以上の結果から、活性点への飽和吸着水（Ｗａｓ）は、以下の（１６）式の関係を有する。
Next, the relationship between the saturated water dissolution amount obtained from the experimental results described later and the acid value will be described in detail. The experimental results on the amount of saturated adsorbed water described below were as follows.
・ Moisture adsorption was proportional to the acid value. That is, it was proportional to the number of active sites.
・ Moisture adsorption is less than the number of active sites at a low temperature of 30 to 35 ° C. That is, water molecules are not preferentially adsorbed on the active sites.
• One or more water molecules were adsorbed on the active site when the temperature was high. In the Langmuir type adsorption, the adsorption is limited by the number of adsorption points. When all the adsorption points are filled with water molecules, no further moisture adsorption occurs and the moisture adsorption amount is saturated. Therefore, it was found that the state of moisture adsorption to the active site is different from the Langmuir type adsorption.
・ It was found that the temperature dependence of the amount of saturated adsorbed water was close to the temperature dependence of the amount of saturated dissolved water. Therefore, it is considered that the amount of saturated dissolved water increases with respect to temperature change and adsorbs in proportion to the concentration, thereby causing temperature dependence of the adsorbed water.
From the above results, the saturated adsorbed water (Was) to the active point has the relationship of the following equation (16).
（１６）式において、Ｃは比例定数、Ａｎ’は[ｍ ＫＯＨ ｍｏｌ／油 ｍｏｌ]単位で表した酸価である。よって、パラメータＣは活性点への水分吸着のしやすさを表し、吸着速度係数に関係する量である。そこで、以下のように（１７）式が得られ、上述の（１５）式と同等となる。 In the formula (16), C is a proportional constant, and An ′ is an acid value expressed in units of [m KOH mol / oil mol]. Therefore, the parameter C represents the ease of moisture adsorption to the active site, and is an amount related to the adsorption rate coefficient. Therefore, the following expression (17) is obtained and is equivalent to the above-described expression (15).
一方、油入電気機器に充填された絶縁油にセルロース系絶縁物が接触している場合について考察する。この場合、セルロース系絶縁物が吸着する水分量を考慮する必要がある。
電気協同研究第６１巻第２号の「変電設備の運用限度評価」第４２頁（社団法人電気協同研究会編）に、絶縁油中水分と絶縁紙の水分平衡について述べられている。
この文献に示されるように、温度が異なると絶縁油−絶縁紙水分平衡関係は異なる。油中水分量は採油後カールフィッシャー法などにより知ることができるが、採油時と異なる温度における油中水分量はそのような絶縁油−絶縁紙水分平衡関係を考慮して任意の温度における油中水分量を求めることができる。そのようにして求めた油中水分量を本発明に係る計算式（４）あるいは計算式（１５）、（１７）で計算される飽和水分溶解量で除して水分飽和度を求め、絶縁油の劣化診断を行うことができる。
On the other hand, the case where the cellulosic insulator is in contact with the insulating oil filled in the oil-filled electrical device will be considered. In this case, it is necessary to consider the amount of moisture adsorbed by the cellulosic insulator.
Electric Cooperative Research Vol. 61, No. 2, “Evaluation of Operation Limits for Substation Equipment”, page 42 (Electric Cooperative Research Association) describes the moisture balance between insulating oil and insulating paper.
As shown in this document, when the temperature is different, the insulating oil-insulating paper moisture balance relationship is different. The amount of water in oil can be determined by the Karl Fischer method after oil collection, etc., but the amount of water in oil at a temperature different from that at the time of oil collection is determined in oil at any temperature in consideration of such insulating oil-insulating paper water balance. The amount of moisture can be determined. The water content in the oil thus obtained is divided by the saturated water dissolution amount calculated by the calculation formula (4) or the calculation formulas (15) and (17) according to the present invention to determine the water saturation, and the insulating oil Can be performed.
水分飽和度が１を超えた絶縁油は、絶縁油中に水滴が生じ、絶縁油の絶縁破壊電圧を著しく低下させる。また、水分飽和度が１に近いほど、絶縁油の絶縁破壊電圧は低下することから、水分飽和度自身が絶縁油の劣化度を表す尺度となる。
また、あらかじめ求めておいた水分飽和度−絶縁破壊電圧曲線を用いて診断することもできる。絶縁油の水分飽和度と絶縁劣化については、たとえば油入電気機器における油中水分量と絶縁破壊電圧の関係について、文献（石井・上田；電気学会論文誌Ｖｏｌ．９２−Ａ，Ｎｏ．３（１９７２））に報告されており、図２に示す関係がある。
Insulating oil having a water saturation exceeding 1 causes water droplets to form in the insulating oil, which significantly lowers the dielectric breakdown voltage of the insulating oil. Further, the closer to 1 the water saturation is, the lower the dielectric breakdown voltage of the insulating oil is. Therefore, the water saturation itself is a scale representing the degree of deterioration of the insulating oil.
Diagnosis can also be made using a moisture saturation-dielectric breakdown voltage curve obtained in advance. Regarding the moisture saturation and insulation deterioration of insulating oil, for example, the relationship between the amount of moisture in oil and the dielectric breakdown voltage in oil-filled electrical equipment, literature (Ishii, Ueda; IEEJ Transactions Vol. 92-A, No. 3 ( 1972)) and has the relationship shown in FIG.
図２に示されるように、横軸の水分飽和度が与えられれば、縦軸の値から絶縁油の絶縁破壊電圧が求められる。電気機器に必要な破壊耐圧を絶縁油が有さないと判定されれば、その絶縁油は劣化して使用に不適であると判定される。
図２では水分飽和度が６０％と算定された場合、該当する絶縁油の破壊電圧が４３ｋＶであることを示しており、この種の絶縁油を用いる電気機器に要求される絶縁破壊電圧が３０ｋＶである場合、この絶縁油は問題ないと判断される。
As shown in FIG. 2, when the water saturation on the horizontal axis is given, the dielectric breakdown voltage of the insulating oil can be obtained from the value on the vertical axis. If it is determined that the insulating oil does not have the breakdown voltage required for the electric device, it is determined that the insulating oil is deteriorated and unsuitable for use.
FIG. 2 shows that when the water saturation is calculated to be 60%, the breakdown voltage of the corresponding insulating oil is 43 kV, and the breakdown voltage required for an electric device using this type of insulating oil is 30 kV. In this case, it is determined that this insulating oil is not a problem.
次に、実施例を示し、本願発明について更に詳細に説明するが、本願発明は以下に説明する実施例に制限されるものではない。
＜実施例１＞
配電用変圧器中のパラフィン系鉱油（絶縁油Ｈ：ＪＩＳ Ｃ２３２０ １種 ２号油）について絶縁劣化診断を行う。
［分子量測定］
絶縁油Ｈの分子量をゲル浸透クロマトグラフィー（ＧＰＣ）法で測定した。測定は試料を移動相（テトラヒドロフラン）で０．１％溶液に調整した液を測定液とし、以下の条件で測定を行った。
Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples described below.
<Example 1>
Diagnosis of insulation deterioration is performed for paraffinic mineral oil (insulation oil H: JIS C2320 type 1 No. 2 oil) in a distribution transformer.
[Molecular weight measurement]
The molecular weight of the insulating oil H was measured by gel permeation chromatography (GPC). The measurement was carried out under the following conditions using a solution prepared by adjusting the sample to a 0.1% solution with a mobile phase (tetrahydrofuran) as a measurement solution.
カラム ：Ｓｈｏｄｅｘ製 ＫＦ−８０１、ＫＦ−８０２
カラム温度 ：４０℃
移動相 ：テトラヒドロフラン
流量 ：１．０ ｍＬ／ｍｉｎ
検出 ：吸光度検出器および示差屈折検出器
注入量 ：２０μＬ
Column: KF-801, KF-802 manufactured by Shodex
Column temperature: 40 ° C
Mobile phase: Tetrahydrofuran flow rate: 1.0 mL / min
Detection: Absorbance detector and differential refraction detector Injection volume: 20 μL
分子量既知の標準物質には鎖状炭化水素（ｎ−ヘキサデカン、ｎ−ドデカン、ｎ−ノナン、ｎ−ヘキサン）および環状炭化水素（ナフタセン、アントラセン、ナフタレン）を用いた。以下の（１８）式により絶縁油の分子量を算出した。 As the standard substances having a known molecular weight, chain hydrocarbons (n-hexadecane, n-dodecane, n-nonane, n-hexane) and cyclic hydrocarbons (naphthacene, anthracene, naphthalene) were used. The molecular weight of the insulating oil was calculated from the following equation (18).
（１８）式において、Ｍ：分子量、Ｎ：分子の個数、Ｈ：ピーク強度（Ｈ＝Ｍ×Ｎ）を意味する。測定の結果、ＧＰＣ法で測定した絶縁油Ｈの分子量は２０９．７であった。 In the formula (18), M: molecular weight, N: number of molecules, H: peak intensity (H = M × N). As a result of the measurement, the molecular weight of the insulating oil H measured by the GPC method was 209.7.
［酸価測定］
絶縁油Ｈの酸価を測定した。
酸価はＪＩＳ Ｃ２１０１「電気絶縁油試験法」に基づき測定した。
試料をトルエン、エタノールの混合溶剤に溶かし、アルカリブルー６Ｂを指示薬として水酸化カリウムの標準エタノール溶液で滴定する。酸価は、以下の（１９）式によって計算した。
[Acid value measurement]
The acid value of the insulating oil H was measured.
The acid value was measured based on JIS C2101 “Electrical Insulating Oil Test Method”.
The sample is dissolved in a mixed solvent of toluene and ethanol, and titrated with a standard ethanol solution of potassium hydroxide using alkali blue 6B as an indicator. The acid value was calculated by the following equation (19).
（１９）式において、ＴＶＡ：酸価［ｍｇＫＯＨ／ｇ］、Ｎ：０．０５ｍｏｌ／ｌの水酸化カリウム標準エタノール溶液の規定度、Ａ”：滴定に要した０．０５ｍｏｌ／ｌの水酸化カリウム標準エタノール溶液の量（ｍｌ）、Ｂ”：空試験に要した０．０５ｍｏｌ／ｌの水酸化カリウム標準エタノール溶液の量（ｍｌ）、Ｗ：試料の質量［ｇ］である。
測定の結果、絶縁油Ｈの酸価は０．０１１［ｍｇＫＯＨ／ｇ］であった。
In the formula (19), TVA: acid value [mg KOH / g], N: normality of 0.05 mol / l potassium hydroxide standard ethanol solution, A ″: 0.05 mol / l potassium hydroxide required for titration Amount of standard ethanol solution (ml), B ″: amount of 0.05 mol / l potassium hydroxide standard ethanol solution required for blank test (ml), W: mass of sample [g].
As a result of the measurement, the acid value of the insulating oil H was 0.011 [mgKOH / g].
［油中水分量］
絶縁油Ｈの油中水分量を測定した。
油中水分量は、ＪＩＳ Ｃ２１０１「電気絶縁油試験法」に基づきカールフィッシャー電量滴定方法によって測定した。カールフィッシャー電量滴定方法は、よう化物イオン、二酸化硫黄を主成分とするピリジン、メタノール混合溶剤に試料を加え、電気分解によってよう素を発生させて水と反応させ、電気量から水の量（μｇ）を求める方法である。
よう素１ｍｏｌは水１ｍｏｌと反応するので、水１ｍｇと反応するのに必要な量のよう素は、１０．７１（Ｃ）の電気量によって発生する。したがって、滴定終点までに消費された電気量を測定すれば、水の量が求められる。電気量は、電解電流を時間について積分することによって求められる。
[Moisture content in oil]
The moisture content of the insulating oil H in the oil was measured.
The amount of water in the oil was measured by the Karl Fischer coulometric titration method based on JIS C2101 “Electrical Insulating Oil Test Method”. The Karl Fischer coulometric titration method involves adding a sample to a mixed solvent of iodide ion, pyridine mainly composed of sulfur dioxide, and methanol, generating iodine by electrolysis and reacting with water. ).
Since 1 mol of iodine reacts with 1 mol of water, the amount of iodine necessary to react with 1 mg of water is generated by an electric quantity of 10.71 (C). Therefore, if the amount of electricity consumed up to the titration end point is measured, the amount of water can be determined. The quantity of electricity is determined by integrating the electrolysis current over time.
水分は、次の式によって計算した。Ｗ＝（Ｇ−ＧＢ）／Ｓ
ここに、Ｗ：水分［ｍｇ／ｋｇ］、Ｇ：試料の水の量［μｇ］、ＧＢ：注射筒を用いた場合のブランクの水の量[μｇ]、Ｓ：試料の質量［ｇ］とする。
測定の結果、絶縁油Ｈの油中水分量は１８［ｍｇ／ｋｇ］であった。
採油時の油温は６０℃であった。
The moisture was calculated by the following formula. W = (G−G B ) / S
Here, W: moisture [mg / kg], G: amount of sample water [μg], G B : amount of blank water [μg] when using a syringe, S: mass of sample [g] And
As a result of the measurement, the moisture content of the insulating oil H in the oil was 18 [mg / kg].
The oil temperature at the time of oil collection was 60 ° C.
［０℃における油中水分量の推定］
変圧器内のセルロース系絶縁物の影響を無視した場合、油温が変化しても油中水分量は変化しないと考えられるので、０℃における絶縁油Ｈの油中水分量も１８［ｍｇ／ｋｇ］と考えられる。
［０℃における飽和溶解水分量］
０℃における飽和水分溶解量を（４）式で計算すると２９．８［ｍｇ／ｋｇ］と推定できる。
[Estimation of water content in oil at 0 ° C]
If the influence of the cellulose-based insulator in the transformer is ignored, it is considered that the moisture content in the oil does not change even if the oil temperature changes. Therefore, the moisture content in the oil of the insulation oil H at 0 ° C. is also 18 mg / mg. kg].
[Saturated dissolved water content at 0 ° C]
When the saturated water dissolution amount at 0 ° C. is calculated by the equation (4), it can be estimated as 29.8 [mg / kg].
［０℃における水分飽和度］
油中水分量１８［ｍｇ／ｋｇ］を飽和溶解水分量２９．８［ｍｇ／ｋｇ］で除すると、０℃における水分飽和度は０．６０と推定できる。
［絶縁油の絶縁劣化診断］
水分飽和度が０．６０であり、１以下なので、絶縁油Ｈ中に水滴は生じないと推定できる。
次に、図２に示す水分飽和度−破壊電圧曲線を用いると、絶縁油Ｈの破壊電圧は４３ｋＶと計算でき、この主の電気機器に要求される絶縁破壊電圧３０ｋＶは超過していることから、この絶縁油Ｈは０℃に油温が下がる場合にも使用可能と判定できる。
[Moisture saturation at 0 ° C]
When the water content in oil 18 [mg / kg] is divided by the saturated dissolved water content 29.8 [mg / kg], the water saturation at 0 ° C. can be estimated to be 0.60.
[Insulation deterioration diagnosis of insulating oil]
Since the water saturation is 0.60 and 1 or less, it can be estimated that no water droplets are generated in the insulating oil H.
Next, when the moisture saturation-breakdown voltage curve shown in FIG. 2 is used, the breakdown voltage of the insulating oil H can be calculated as 43 kV, and the
＜実施例２＞
配電用変圧器中の絶縁油Ｈについてセルロース系絶縁紙に絶縁油が接触していることを考慮した絶縁劣化診断を行った。
［分子量測定］
絶縁油Ｈの分子量は実施例１で測定した通り２０９．７であった。
［酸価測定］
絶縁油Ｈの酸価は実施例１で示した通り０．０１１［ｍｇＫＯＨ／ｇ］であった。
［油中水分量］
絶縁油Ｈの油中水分量は実施例１で示した通り１８［ｍｇ／ｋｇ］であった。採油時の油温は６０℃であった。
<Example 2>
With respect to the insulating oil H in the distribution transformer, an insulation deterioration diagnosis was performed considering that the insulating oil was in contact with the cellulose insulating paper.
[Molecular weight measurement]
The molecular weight of the insulating oil H was 209.7 as measured in Example 1.
[Acid value measurement]
The acid value of the insulating oil H was 0.011 [mgKOH / g] as shown in Example 1.
[Moisture content in oil]
The moisture content of the insulating oil H in the oil was 18 [mg / kg] as shown in Example 1. The oil temperature at the time of oil collection was 60 ° C.
［０℃における油中水分量の推定］
変圧器中のセルロース系絶縁紙を考慮すると油温が変化すると油中水分量も変化する。
電気協同研究第６１巻第２号「変電設備の運用限度評価」第４３頁（社団法人電気協同研究会編）には、第６―１−５図に絶縁油中水分量と絶縁紙中水分量の関係と題して、図４が示されている。前記文献の第６―１−５図に示す関係について、油中水分量を０〜３０[ｍｇ／ｋｇ]、紙中水分量を０〜２．０[％]の範囲で作図したのが図４である。
図４には、絶縁油中水分量と絶縁紙中水分量の関係について、０℃〜１００℃までの温度１０℃毎の関係曲線が描かれている。図４に示す関係曲線を用いて、０℃における油中水分量を推定できる。
[Estimation of water content in oil at 0 ° C]
Considering the cellulosic insulating paper in the transformer, the water content in the oil changes as the oil temperature changes.
Electrical Cooperative Research Vol. 61, No. 2, “Evaluation of Operation Limits for Substation Equipment”, p. 43 (Electric Cooperative Research Association), Fig. 6-1-5 shows the moisture content in insulating oil and the moisture content in insulating paper. FIG. 4 is shown as a quantity relationship. Regarding the relationship shown in Fig. 6-1-5 in the above document, the water content in the oil was plotted in the range of 0-30 [mg / kg] and the water content in the paper was in the range of 0-2.0 [%]. 4.
FIG. 4 shows a relationship curve for each temperature of 10 ° C. from 0 ° C. to 100 ° C. with respect to the relationship between the moisture content in the insulating oil and the moisture content in the insulating paper. The water content in oil at 0 ° C. can be estimated using the relationship curve shown in FIG.
本実施例に供した当該変圧器の絶縁油量は１１４００ｋｇである。この変圧器においてプレスボード紙は厚いため、含まれる水分量の変化は遅いと仮定し、温度変化に伴う油中水分変化に寄与するセルロース系絶縁紙はコイル絶縁紙のみと仮定すると、当該変圧器の絶縁紙量は１５５ｋｇである。これらの絶縁紙量から６０℃の油温が冷えて０℃になった時の油中水分量は約１．５［ｍｇ／ｋｇ］と推定できる。
詳述すると、絶縁油Ｈの油中水分量が実施例１で示した通り１８［ｍｇ／ｋｇ］であり、採油時の油温が６０℃である場合、図４の横軸に示す１８［ｍｇ／ｋｇ］の位置から油温６０℃の線に向かって補助線Ｈ１を策定し、交差した位置の縦軸が示す紙中水分量は、補助線Ｈ２が縦軸と交差する点が示すように１．３％とわかる。これが０℃となった場合にどうなるか推定する。
The amount of insulating oil of the transformer used in this example is 11400 kg. In this transformer, since the pressboard paper is thick, it is assumed that the change in the amount of water contained is slow, and if the cellulosic insulation paper that contributes to the moisture change in oil accompanying the temperature change is only the coil insulation paper, the transformer The amount of insulating paper is 155 kg. The amount of water in oil when the oil temperature at 60 ° C. is cooled to 0 ° C. can be estimated to be about 1.5 [mg / kg] from the amount of insulating paper.
Specifically, when the moisture content in the oil of the insulating oil H is 18 [mg / kg] as shown in Example 1 and the oil temperature at the time of oil collection is 60 ° C., 18 [ mg / kg] direction from the position of the lines of the
ここで水分は絶縁油に含まれている水分と絶縁紙の中に含まれている水分の２種類あるが、絶縁紙に一部水分が移ったと仮定すると、２種類の水分の総量は同じなので、この２種類の水分量の総和は、一定になると考えられる。そこで、２種類の水分量の総和が一定になるような補助線Ｈ３を描くと、図４の補助線Ｈ３のようになる。この補助線Ｈ３と油温０℃の曲線の交わる点Ｈ５を求めると、この点Ｈ５に対応する横軸の油中水分量は１．５[ｍｇ／ｋｇ]と見積もることができる。
［０℃における飽和溶解水分量］
絶縁油Ｈの０℃における飽和溶解水分量は実施例１で示した通り（４）式で計算すると２９．８［ｍｇ／ｋｇ］と推定できる。
［０℃における水分飽和度］
油中水分量１．５［ｍｇ／ｋｇ］を飽和溶解水分量２９．８［ｍｇ／ｋｇ］で除すると、０℃における水分飽和度は０．０５と推定できる。
Here, there are two types of moisture: the moisture contained in the insulating oil and the moisture contained in the insulating paper, but assuming that some moisture has moved to the insulating paper, the total amount of the two types of moisture is the same. The sum of the two types of moisture is considered to be constant. Therefore, the two kinds of water content of total draw an auxiliary line H 3 as a constant, so that the auxiliary line H 3 in FIG. When seeking H 5 points of intersection of the curve of the auxiliary line H 3 oil temperature 0 ° C., oil water content of the horizontal axis corresponding to the point H 5 can be estimated to be 1.5 [mg / kg].
[Saturated dissolved water content at 0 ° C]
The saturated dissolved water content at 0 ° C. of the insulating oil H can be estimated as 29.8 [mg / kg] when calculated by the equation (4) as shown in Example 1.
[Moisture saturation at 0 ° C]
When the water content in oil 1.5 [mg / kg] is divided by the saturated dissolved water content 29.8 [mg / kg], the water saturation at 0 ° C. can be estimated to be 0.05.
［絶縁油の絶縁劣化診断］
水分飽和度が０．０５であり、１以下なので絶縁油中に水滴は生じないと推定できる。
図２に示す水分飽和度−破壊電圧曲線を用いると、絶縁油Ｈの破壊電圧は９０ｋＶと計算でき、この絶縁油を適用する電気機器に要求される絶縁破壊電圧３０ｋＶは超過していることから、この絶縁油は０℃に油温が下がる場合にも使用可能と判定できる。
[Insulation deterioration diagnosis of insulating oil]
Since the water saturation is 0.05 and 1 or less, it can be estimated that no water droplets are generated in the insulating oil.
If the moisture saturation-breakdown voltage curve shown in FIG. 2 is used, the breakdown voltage of the insulating oil H can be calculated as 90 kV, and the
次に、図５と図６を用いて従来知られている飽和水分溶解量の計算に用いる（３）式と先に飽和水分溶解量の計算に用いた（４）式の対比について検証する。
図５は先に記載した非特許文献４のＰ２８に記載のテーブル５に表示されているMladenovらが行った絶縁油における、飽和水分溶解量Ｗｓの計算値とＷｓの実測値の対比をグラフ化した図である。Mladenovらが行った計算モデルは、先に（３）式で示した計算式に基づいている。
Next, the comparison between the conventionally known equation (3) used for calculating the saturated water dissolution amount and the equation (4) previously used for calculating the saturated water dissolution amount will be verified with reference to FIGS.
FIG. 5 is a graph showing a comparison between the calculated value of the saturated water dissolution amount Ws and the actual measurement value of Ws in the insulating oil performed by Mladenov et al. Displayed in the table 5 described in P28 of
図５に示す結果からわかるように、Mladenovらが行った（３）式を用いた従来の計算式で得られる結果においては、飽和水分溶解量Ｗｓの計算値とＷｓの実測値の対比結果からみると、飽和水分溶解量Ｗｓの値が１００〜３００前後の範囲では計算モデルの相関性が高いが、飽和水分溶解量の値が３６０を超える辺りの試料から飽和水分溶解量Ｗｓの実測値とＷｓの計算値の乖離が大きくなり、２０％以上の乖離が生じている。 As can be seen from the results shown in FIG. 5, in the result obtained by the conventional calculation formula using the formula (3) performed by Mladenov et al., From the comparison result of the calculated value of the saturated water dissolution amount Ws and the measured value of Ws. When the value of the saturated water dissolution amount Ws is in the range of about 100 to 300, the correlation of the calculation model is high, but the measured value of the saturated water dissolution amount Ws from the sample around the value of the saturated water dissolution amount exceeding 360 is The divergence of the calculated value of Ws increases, and a divergence of 20% or more occurs.
＜実施例３＞
図６は本発明に係る計算モデルにおいて絶縁油の飽和水分溶解量Ｗｓの計算値とＷｓの実測値の対比をグラフ化した図である。
図６のグラフに示すデータは以下の各種絶縁油を用いて上述の（１５）式に従い計算した結果である。
（１５）式において、Ａ＝６．５２４、Ｂ＝１５６７、Ｃ＝０．００８９を適用した。
<Example 3>
FIG. 6 is a graph showing a comparison between the calculated value of the saturated water dissolution amount Ws of the insulating oil and the measured value of Ws in the calculation model according to the present invention.
The data shown in the graph of FIG. 6 is the result of calculation according to the above equation (15) using the following various types of insulating oil.
In the formula (15), A = 6.524, B = 1567, and C = 0.895 were applied.
以下の表２に、試験に使用した絶縁油別に計算に使用した酸価[ｍｇＫＯＨ／ｇ]、分子量[ｇ／ｍｏｌ]、絶対温度[Ｋ]、飽和水分溶解量実測値[ｍｇ／ｋｇ]、飽和水分溶解量計算値[ｍｇ／ｋｇ]、差分[ｍｇ／ｋｇ]、計算値の実測値からの乖離割合（％）について、まとめて記載する。 Table 2 below shows the acid value [mg KOH / g], molecular weight [g / mol], absolute temperature [K], and saturated water solubility actually measured value [mg / kg] used for the calculation for each insulating oil used in the test. The saturated water solubility calculation value [mg / kg], the difference [mg / kg], and the deviation rate (%) from the actual measurement value are collectively described.
以下、表２〜表４に示す絶縁油Ａ６は、ＪＸ日航日石エネルギー株式会社製高圧絶縁油Ｂ１１Ａ、絶縁油Ｂ６は、ＪＸ日航日石エネルギー株式会社製高圧絶縁油Ｋ、絶縁油Ｃ６は、昭和シェル石油株式会社製シェルトランスオイルＡ、絶縁油Ｄ６は、昭和シェル石油株式会社製シェルトランスオイルＢ、絶縁油Ｅは、出光興産株式会社出光トランスフォーマーオイルＨ、絶縁油Ｆは、出光興産株式会社出光トランスフォーマーオイルＧ、絶縁油Ｈ、Ｉ、Ｊは、ＪＩＳ Ｃ２３２０ １種 ２号油（パラフィン系鉱油）である。
ここで強制劣化油とは、Ａ６’、Ｃ６’、Ｈ’、Ｂ６’のことであり、強制劣化油のＡ６’（Ｎｏ.８、９、１０）、Ｃ６’（Ｎｏ.１１、１２、１３）、Ｈ’（Ｎｏ.１４、１５、１６）、Ｂ６’（Ｎｏ.１７、１８、１９）はそれぞれ空気密封、銅触媒共存、１２０℃で４８時間、９６時間、１４４時間加熱、Ａ６’（Ｎｏ.２３，２４）の２試料は空気中、銅触媒なし、１４０℃で１９日間、２９日間加熱を行うことにより作成した絶縁油を示す。
Hereinafter, the insulating oil A 6 shown in Table 2 to Table 4, JX Nikko Oil & Energy Corporation steel high pressure insulating oil B11A, insulating oil B 6 is, JX Nikko Oil & Energy Corporation steel high pressure insulating oil K, insulating oil C 6 is Showa Shell Sekiyu KK Shell Transformer Oil A, Insulating Oil D 6 is Showa Shell Sekiyu KK Shell Transformer Oil B, Insulating Oil E is Idemitsu Kosan Co., Ltd. Idemitsu Transformer Oil H, Insulating Oil F is Idemitsu Kosan Co., Ltd. Idemitsu Transformer Oil G, Insulating Oils H, I, and J are JIS C2320 Type 1 No. 2 oil (paraffinic mineral oil).
Here, the forcedly deteriorated oil is A 6 ′, C 6 ′, H ′, B 6 ′, and A 6 ′ (No. 8, 9, 10) or C 6 ′ (No. 11, 12, 13), H ′ (No. 14, 15, 16) and B 6 ′ (No. 17, 18, 19) are air sealed, coexisting with copper catalyst, 48 ° C. at 120 ° C., 96 hours, 144 Two samples of time heating, A 6 ′ (No. 23, 24) represent insulating oils prepared by heating in air, without a copper catalyst, at 140 ° C. for 19 days and 29 days.
以下の表３に、使用した絶縁油別に計算した酸価[ｍｇＫＯＨ／ｇ]、分子量[ｇ／ｍｏｌ]（ＧＰＣ法による）、絶対温度[Ｋ]、飽和水分溶解量実測値[ｍｇ／ｋｇ]、飽和水分溶解量計算値[ｍｇ／ｋｇ]、差分[ｍｇ／ｋｇ]、計算値の実測値からの乖離割合（％）についてまとめて記載する。 Table 3 below shows the acid value [mg KOH / g], molecular weight [g / mol] (according to GPC method), absolute temperature [K], and measured value of dissolved saturated water [mg / kg] calculated for each insulating oil used. The saturated water dissolution amount calculated value [mg / kg], the difference [mg / kg], and the deviation rate (%) from the measured value of the calculated value are collectively described.
図６と表２、表３に示す結果から明らかなように、本発明に係る計算式により求めた絶縁油の飽和水分溶解量Ｗｓの計算値とＷｓの実測値は相関性が高く、飽和水分溶解量Ｗｓが１００〜６００の範囲で優れた値を示した。また、実測値からの乖離においては、１０％程度以下に抑えられている。このことから、本発明に係る計算式の有効性の高いことがわかる。 As is apparent from the results shown in FIG. 6, Table 2, and Table 3, the calculated value of the saturated water dissolution amount Ws of the insulating oil obtained by the calculation formula according to the present invention and the measured value of Ws are highly correlated, and the saturated water content Excellent values were obtained when the dissolution amount Ws was in the range of 100 to 600. Further, the deviation from the actually measured value is suppressed to about 10% or less. From this, it can be seen that the calculation formula according to the present invention is highly effective.
＜比較例＞
次に、先の（１５）式を用いて上記実施例と同じ絶縁油の飽和水分溶解量を計算した。ただしこの計算の際、先のＧＰＣ法に基づく分子量の値に代えて、動粘度から分子量を算出する方法（ＡＳＴＭ Ｄ２５０２）により分子量を求めた。計算結果を以下の表４に記載する。
<Comparative example>
Next, the saturated water dissolution amount of the same insulating oil as in the above example was calculated using the above equation (15). However, in this calculation, instead of the molecular weight value based on the previous GPC method, the molecular weight was determined by a method (ASTM D2502) for calculating the molecular weight from the kinematic viscosity. The calculation results are listed in Table 4 below.
表４に示す結果から明らかなように、推定式にＡＳＴＭによる分子量測定結果を利用しても絶縁油の飽和水分溶解量Ｗｓの計算値とＷｓの実測値は相関性が低く、実測値からの乖離においては、最大２０％を超える乖離となった。このことから、推定式にＧＰＣ法による分子量を採用することの有効性が高いことが判明した。
ＡＳＴＭによる分子量測定は、新油を対象とした試験方法であるため、劣化油や実器使用油の評価には適していないことがわかった。なお、この原因は、ＡＳＴＭによる分子量測定が動粘度を基にしているが、絶縁油の動粘度は絶縁油の多少の劣化では変化しないと考えられるので、分子量測定値が絶縁油劣化の実情に合っていないことが原因と推定される。
以上の試験結果から、分子量の違いを考慮した飽和水分溶解量と酸価との関係性について検討した結果、絶縁油の飽和水分溶解量の正確な評価には分子量の測定が必要であり、その測定には芳香族分および劣化による分子量の違いを分子量測定結果に反映することができるＧＰＣ法による分子量測定が有効であることがわかった。
As is clear from the results shown in Table 4, even if the molecular weight measurement result by ASTM is used in the estimation formula, the calculated value of the saturated water solubility Ws of the insulating oil and the actual measured value of Ws are low in correlation, and The divergence exceeded 20% at the maximum. From this, it was found that the effectiveness of adopting the molecular weight by the GPC method in the estimation formula is high.
Since the molecular weight measurement by ASTM is a test method for new oil, it was found that it is not suitable for evaluation of deteriorated oil or oil used in actual equipment. This is because the molecular weight measurement by ASTM is based on the kinematic viscosity, but the kinematic viscosity of the insulating oil is considered not to change with some deterioration of the insulating oil. It is presumed that this is not the case.
From the above test results, as a result of examining the relationship between the saturated water dissolution amount and the acid value in consideration of the difference in molecular weight, it is necessary to measure the molecular weight for accurate evaluation of the saturated water dissolution amount of the insulating oil. It was found that the molecular weight measurement by the GPC method, which can reflect the difference in aromatic content and molecular weight due to deterioration in the molecular weight measurement results, is effective for the measurement.
＜計算例＞
次に、絶縁油間の分子量の違いを考慮するため、単位重量当たりの水分量に絶縁油の分子量を掛けた単位分子数当たりの水分量として飽和水分溶解量を評価した。単位分子数当たりの水分量では、絶縁油の分子数を等しくしたことにより、分子量が異なる絶縁油であっても水分量の比較が可能になると思われる。さらに、酸価も単位重量当たりの水酸化カリウム消費量であることから、酸価についても単位分子数当たりの水酸化カリウム消費量へ換算した。計算例を以下に示す。
<Calculation example>
Next, in order to consider the difference in molecular weight between the insulating oils, the saturated water dissolution amount was evaluated as the water amount per unit molecule number obtained by multiplying the water amount per unit weight by the molecular weight of the insulating oil. With regard to the amount of water per unit molecule, it is considered that the amount of water can be compared even with insulating oils having different molecular weights by equalizing the number of molecules of insulating oil. Furthermore, since the acid value is also the amount of potassium hydroxide consumed per unit weight, the acid value was also converted to the amount of potassium hydroxide consumed per number of unit molecules. An example of calculation is shown below.
計算例（ＪＸ日航日石エネルギー株式会社製高圧絶縁油Ｂ１１Ａ（市販絶縁油Ａ）：芳香族分８．８％、ＪＩＳ Ｃ２３２０ １種 ２号油（パラフィン系鉱油）（実器使用油Ｈ）：芳香族分１７．７％）
○飽和水分溶解量（単位分子数）［ｍｇ／ｍｏｌ］ ＝
飽和水分溶解量（単位重量）［ｍｇ／ｋｇ］× 絶縁油分子量［ｇ／ｍｏｌ］×１０−３ ［ｋｇ／ｇ］
市販絶縁油Ａ：９９．５［ｍｇ／ｋｇ］×２８８．９［ｇ／ｍｏｌ］×１０−３［ｋｇ／ｇ］ ＝ ２８．７［ｍｇ／ｍｏｌ］
実器使用油Ｈ：１３１．６［ｍｇ／ｋｇ］×２０９．７［ｇ／ｍｏｌ］×１０−３ ［ｋｇ／ｇ］＝２７．６［ｍｇ／ｍｏｌ］
○酸価（単位分子数）［ｍｇＫＯＨ／ｍｏｌ］＝
酸価（単位重量）［ｍｇＫＯＨ／ｇ］×絶縁油分子量［ｇ／ｍｏｌ］
市販絶縁油Ａ：０．００８［ｍｇＫＯＨ／ｇ］×２８８．９［ｇ／ｍｏｌ］＝２．３［ｍｇＫＯＨ／ｍｏｌ］
実器使用油Ｈ：０．０１１［ｍｇＫＯＨ／ｇ］×２０９．７［ｇ／ｍｏｌ］＝２．３ ［ｍｇＫＯＨ／ｍｏｌ］
Calculation example (high-pressure insulating oil B11A (commercial insulating oil A) manufactured by JX Nippon Oil & Energy Corporation: aromatic content 8.8%, JIS C2320 type 1 oil (paraffinic mineral oil) (actual oil H used): Aromatic content 17.7%)
○ Saturated water solubility (unit molecular number) [mg / mol] =
Saturated water solubility (unit weight) [mg / kg] × insulating oil molecular weight [g / mol] × 10 −3 [kg / g]
Commercial insulating oil A: 99.5 [mg / kg] × 288.9 [g / mol] × 10 −3 [kg / g] = 28.7 [mg / mol]
Actual oil used H: 131.6 [mg / kg] × 209.7 [g / mol] × 10 −3 [kg / g] = 27.6 [mg / mol]
○ Acid value (number of unit molecules) [mgKOH / mol] =
Acid value (unit weight) [mg KOH / g] x insulating oil molecular weight [g / mol]
Commercial insulating oil A: 0.008 [mg KOH / g] × 288.9 [g / mol] = 2.3 [mg KOH / mol]
Actual oil used H: 0.011 [mgKOH / g] × 209.7 [g / mol] = 2.3 [mgKOH / mol]
上述した計算例の関係において、単位重量当たりの飽和水分溶解量では市販絶縁油Ａと実器使用油Ｈで約３０[ｍｇ／ｋｇ]の差が見られていたが、単位分子数当たりの飽和水分溶解量に換算した結果、市販絶縁油Ａと実器使用油Ｈの飽和水分溶解量がほぼ同等となり、芳香族分の違いをＧＰＣ法による分子量で整理可能であることがわかった。 In the relationship of the calculation example described above, a difference of about 30 [mg / kg] was observed between the commercially available insulating oil A and the actual equipment use oil H in the saturated water dissolution amount per unit weight, but the saturation per unit number of molecules. As a result of conversion into the amount of water dissolved, it was found that the saturated water dissolved amount of the commercially available insulating oil A and the actual equipment use oil H became almost equal, and the difference in aromatic content could be organized by the molecular weight by the GPC method.
次に、単位分子数当たりに換算した時の酸価と飽和水分溶解量の関係を図８に示す。図８に示す各市販絶縁油は、先の実施例において用いたものと同等の絶縁油を示す。
図８より、芳香族分および劣化による分子量の違いを考慮した結果、飽和水分溶解量と酸価との間に良好な関係性（相関係数Ｒ＝０．９７１）が認められた。これまでは絶縁油の劣化による活性点の増加に加えて、分子量の変化が影響していたため、酸価と飽和水分溶解量を精度良く関係付けることが出来なかったと考えられる。
Next, FIG. 8 shows the relationship between the acid value when converted per unit number of molecules and the saturated water dissolution amount. Each commercially available insulating oil shown in FIG. 8 shows the insulating oil equivalent to what was used in the previous Example.
From FIG. 8, as a result of considering the difference in the molecular weight due to the aromatic content and deterioration, a good relationship (correlation coefficient R = 0.971) was found between the saturated water dissolution amount and the acid value. So far, in addition to the increase in active sites due to the deterioration of insulating oil, the change in molecular weight has affected, so it is considered that the acid value and the amount of dissolved saturated water could not be related accurately.
図９は、表３に示す試験結果から求めた酸価増加分と分子量増加分の相関関係を示す図である。例えば、表３の絶縁油Ａ６と絶縁油Ａ６’は強制劣化前後の絶縁油の関係を示すので、酸価の変化と分子量の変化がそれぞれわかるので、これらの結果を図９にプロットし、表３に示す他の絶縁油について各々図９にプロットすると、図９を描くことができる。
絶縁油は酸化劣化すると、分子数が増加することがわかっている。酸化の程度は酸価を尺度として評価できる。酸価増加量に対し、分子量はほぼ直線的に増加する。未使用時の絶縁油の酸価はほぼ０である。よって、未使用時絶縁油の分子量が既知の場合、酸化劣化後の分子量は酸価から推測することができ、酸価を測定するだけで飽和水分溶解量が推測できる。また、未使用時絶縁油の分子量が未知の場合、その代表的な値である２８０を初期値として、酸価から分子量を推測できる。
FIG. 9 is a diagram showing the correlation between the acid value increase and the molecular weight increase determined from the test results shown in Table 3. For example, insulating oil A 6 and insulating oil A 6 ′ in Table 3 show the relationship between the insulating oil before and after the forced deterioration, so that the change in acid value and the change in molecular weight can be seen, so these results are plotted in FIG. FIG. 9 can be drawn by plotting the other insulating oils shown in Table 3 in FIG. 9.
Insulating oils are known to increase in molecular number when oxidized. The degree of oxidation can be evaluated using the acid value as a scale. The molecular weight increases almost linearly with increasing acid value. The acid value of the insulating oil when not in use is almost zero. Therefore, when the molecular weight of the unused insulating oil is known, the molecular weight after oxidative degradation can be estimated from the acid value, and the saturated water dissolution amount can be estimated only by measuring the acid value. Further, when the molecular weight of the insulating oil when not in use is unknown, the molecular weight can be estimated from the acid value with 280, which is a representative value, as an initial value.
図１０は、酸価と飽和水分溶解量（重量単位）の関係を前述の各種絶縁油に対し測定した結果を示す。
図１０の関係からでは、酸価の増大に伴って飽和水分溶解量も増加する傾向が認められるが、その相関には、ばらつき（相関係数Ｒ＝０．７６６）が見られたので、単位重量当たりで酸価と飽和水分溶解量の関係を求めたとしても、両者の間に相関関係を把握することはできない。
以上の対比から、これらの飽和水分溶解量の表示方法（単位）に問題があることがわかる。例えば、絶縁油の飽和水分溶解量を絶縁油単位重量当たりの水分量で表す従来方法では、比較する絶縁油の分子量が同一であることが前提となる。分子量が大きい絶縁油と分子量が小さい絶縁油へ水１分子が溶解した場合の水分量を考えた場合、どちらの場合も油分子数と水分子数の割合は同じであるが、単位重量当たりの水分量で表すと、分子量が小さいほど、単位重量当たりの水分量は多くなると考えられる。このため、本発明方法において採用している単位分子量当たりの飽和水分溶解量の概念が重要であることがわかる。
FIG. 10 shows the results of measuring the relationship between the acid value and the saturated water dissolution amount (weight unit) for the various insulating oils described above.
From the relationship shown in FIG. 10, it is recognized that the saturated water dissolution amount tends to increase as the acid value increases. However, since there is a variation (correlation coefficient R = 0.766) in the correlation, the unit Even if the relationship between the acid value per unit weight and the dissolved amount of saturated water is obtained, the correlation cannot be grasped between them.
From the above comparison, it is understood that there is a problem in the display method (unit) of these saturated water dissolution amounts. For example, in the conventional method in which the saturated water dissolution amount of the insulating oil is expressed by the amount of water per unit weight of the insulating oil, it is assumed that the molecular weights of the insulating oils to be compared are the same. Considering the amount of water when one molecule of water is dissolved in insulating oil with a high molecular weight and insulating oil with a low molecular weight, the ratio of the number of oil molecules to the number of water molecules is the same in both cases, but In terms of water content, the smaller the molecular weight, the greater the water content per unit weight. For this reason, it is understood that the concept of the saturated water dissolution amount per unit molecular weight adopted in the method of the present invention is important.
１…収容器（デシケーター）、２…水、３…容器（ビーカー）、４…絶縁油、５…容器（ビーカー）。 DESCRIPTION OF SYMBOLS 1 ... Container (desiccator), 2 ... Water, 3 ... Container (beaker), 4 ... Insulating oil, 5 ... Container (beaker).
Claims (6)
前記油中水分量を飽和水分溶解量で除した水分飽和度を求め、この水分飽和度が１を超えるか、１に近いほど、絶縁油の劣化が進んでいると判断することを特徴とする電気機器中絶縁油の絶縁劣化診断方法。 The measured value of the molecular weight of the insulating oil filled in the electrical equipment by the gel permeation chromatography method and the acid value indicated by the number of mg of potassium hydroxide required to neutralize all acidic components contained in 1 g of insulating oil. The measured value and the weight of moisture in oil expressed in mg, and the value of moisture in oil divided by the number of moles of insulating oil and indicated as 10 ( AB / T) as a function of absolute temperature Using the saturated water dissolution amount calculated by multiplying the calculation formula (A and B are parameters) by the acid value expressed in units of [mKOH mol / oil mol] and the degree of influence thereof,
The water saturation obtained by dividing the water content in the oil by the saturated water dissolution amount is obtained, and it is determined that the deterioration of the insulating oil is advanced as the water saturation exceeds 1 or is close to 1. Insulation deterioration diagnosis method for insulating oil in electrical equipment.
前記油中水分量を飽和水分溶解量で除した水分飽和度を求め、この水分飽和度が１を超えるか、１に近いほど、絶縁油の劣化が進んでいると判断することを特徴とする電気機器中絶縁油の絶縁劣化診断方法。 Estimate the molecular weight after oxidative degradation based on the molecular weight of the insulating oil when not in use, based on the correlation between the increase in the acid value of the insulating oil filled in the electrical equipment and the increase in the molecular weight of the insulating oil. Measured molecular weight, acid value measured in mg of potassium hydroxide required to neutralize all acidic components contained in 1 g of insulating oil, and weight of water in oil expressed in mg In the calculation formula (A and B are parameters) represented by 10 ( AB / T) as a function of absolute water temperature and the value of moisture content in oil divided by the number of moles of insulating oil, [mKOH mol / oil mol ] Use the saturated water solubility calculated by multiplying the acid value expressed in units by the degree of its influence,
The water saturation obtained by dividing the water content in the oil by the saturated water dissolution amount is obtained, and it is determined that the deterioration of the insulating oil is advanced as the water saturation exceeds 1 or is close to 1. Insulation deterioration diagnosis method for insulating oil in electrical equipment.
Ｗｓ[mg/mol]＝（１＋Ｃ×Ａｎ’）１０（Ａ−Ｂ／Ｔ） で示す推定式を用いることを特徴とする請求項１または２に記載の電気機器中絶縁油の絶縁劣化診断方法。
ただし、前記推定式において、パラメータＣは酸価の影響度合いを示す量、Ａｎ’は[ｍ ＫＯＨ ｍｏｌ／油 ｍｏｌ]単位で表した酸価を表し、パラメータＡは、反応式Ｈ２Ｏ＋Ｈ２Ｏ⇔（Ｈ２Ｏ）２に対する結合反応速度と分解反応速度の比に関係する量、パラメータＢは水の蒸発潜熱に関係する量、Ｔは絶対温度を示す。 As the value of the saturated water dissolution amount (Ws [mg / mol]),
The method for diagnosing insulation deterioration of insulating oil in electrical equipment according to claim 1 or 2, wherein an estimation formula represented by Ws [mg / mol] = (1 + C x An ') 10 (AB / T) is used. .
In the above estimation formula, parameter C is an amount indicating the degree of influence of the acid value, An ′ is an acid value expressed in units of [m KOH mol / oil mol], and parameter A is a reaction formula H 2 O + H 2 O. An amount related to the ratio of the binding reaction rate to the decomposition reaction rate for ⇔ (H 2 O) 2 , parameter B is an amount related to the latent heat of vaporization of water, and T is an absolute temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012171440A JP5976439B2 (en) | 2012-08-01 | 2012-08-01 | Insulation deterioration diagnosis method for insulating oil in electrical equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012171440A JP5976439B2 (en) | 2012-08-01 | 2012-08-01 | Insulation deterioration diagnosis method for insulating oil in electrical equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2014032047A true JP2014032047A (en) | 2014-02-20 |
| JP5976439B2 JP5976439B2 (en) | 2016-08-23 |
Family
ID=50281991
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2012171440A Active JP5976439B2 (en) | 2012-08-01 | 2012-08-01 | Insulation deterioration diagnosis method for insulating oil in electrical equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5976439B2 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5692468A (en) * | 1979-12-26 | 1981-07-27 | Fuji Electric Co Ltd | Method for decision of degree of deterioration of synthetic insulating oil |
| JPS63172974A (en) * | 1987-01-12 | 1988-07-16 | Toshiba Corp | Insulation deterioration diagnosing method for oil-filled electric equipment |
| JP2004061384A (en) * | 2002-07-30 | 2004-02-26 | Yuka Ind:Kk | Method for inferring moisture content of insulating paper in oil-filled electric device and diagram for inferring used for the same |
| JP2010256208A (en) * | 2009-04-27 | 2010-11-11 | Tokyo Electric Power Co Inc:The | Method for diagnosing secular deterioration of insulating oil in electric device |
-
2012
- 2012-08-01 JP JP2012171440A patent/JP5976439B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5692468A (en) * | 1979-12-26 | 1981-07-27 | Fuji Electric Co Ltd | Method for decision of degree of deterioration of synthetic insulating oil |
| JPS63172974A (en) * | 1987-01-12 | 1988-07-16 | Toshiba Corp | Insulation deterioration diagnosing method for oil-filled electric equipment |
| JP2004061384A (en) * | 2002-07-30 | 2004-02-26 | Yuka Ind:Kk | Method for inferring moisture content of insulating paper in oil-filled electric device and diagram for inferring used for the same |
| JP2010256208A (en) * | 2009-04-27 | 2010-11-11 | Tokyo Electric Power Co Inc:The | Method for diagnosing secular deterioration of insulating oil in electric device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5976439B2 (en) | 2016-08-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Du et al. | Moisture solubility for differently conditioned transformer oils | |
| Suleiman et al. | Effect of moisture on breakdown voltage and structure of palm based insulation oils | |
| Amimoto et al. | Duration and mechanism for suppressive effect of triazole-based passivators on copper-sulfide deposition on insulating paper | |
| Ren et al. | Influence of the atmosphere on the reaction of dibenzyl disulfide with copper in mineral insulation oil | |
| Martin et al. | Preliminary results for dissolved gas levels in a vegetable oil-filled power transformer | |
| Pasaribu | Thermal Aging of Mineral Oil-Paper Composite Insulation for High Voltage Transformer. | |
| Kurzweil et al. | Environmental impact and aging properties of natural and synthetic transformer oils under electrical stress conditions | |
| Ghani et al. | A study of moisture effects on the breakdown voltage and spectral characteristics of mineral and palm oil-based insulation oils | |
| Rehman et al. | Experimental investigation of temperature effect on corrosive sulfur formation in transformers | |
| Wada et al. | Method to evaluate the degradation condition of transformer insulating oil-establishment of the evaluation method and application to field transformer oil | |
| Gorgan et al. | Calculation of power transformers health indexes | |
| Amalanathan et al. | Streaming electrification of different insulating fluids in power transformers | |
| Amaro et al. | Tracking copper sulfide formation in corrosive transformer oil | |
| Akshatha et al. | Study of degradation of sulphur compounds and depletion of metal passivators during thermal ageing of mineral oil | |
| JP5976439B2 (en) | Insulation deterioration diagnosis method for insulating oil in electrical equipment | |
| EP3473991B1 (en) | Method for estimating overheated temperature of oil-filled electric device | |
| JP2004061384A (en) | Method for inferring moisture content of insulating paper in oil-filled electric device and diagram for inferring used for the same | |
| JP5337303B2 (en) | Diagnostic method and apparatus for oil-filled electrical equipment | |
| Mladenov et al. | Water saturation limit of transformer oils | |
| Muhamad et al. | Dissolved gas analysis (DGA) of arcing faults in biodegradable oil insulation systems | |
| JP5079936B1 (en) | Diagnostic method for oil-filled electrical equipment | |
| Khan et al. | An experimental study on the effects of DBDS in transformer oil of power transformers | |
| Phalphale et al. | Investigation of transformer oil exposed to the atmosphere | |
| Mitchinson et al. | Investigation into the formation of copper sulphide in oil filled electrical equipment | |
| Bandara et al. | Investigation of moisture influence on dielectric response of ester oil impregnated pressboard |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20150708 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20160526 |
|
| 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: 20160621 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20160720 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5976439 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |