JP5796783B2 - Composite paper solid cable - Google Patents

Composite paper solid cable Download PDF

Info

Publication number
JP5796783B2
JP5796783B2 JP2012160020A JP2012160020A JP5796783B2 JP 5796783 B2 JP5796783 B2 JP 5796783B2 JP 2012160020 A JP2012160020 A JP 2012160020A JP 2012160020 A JP2012160020 A JP 2012160020A JP 5796783 B2 JP5796783 B2 JP 5796783B2
Authority
JP
Japan
Prior art keywords
composite paper
paper
insulating oil
composite
oil
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.)
Active
Application number
JP2012160020A
Other languages
Japanese (ja)
Other versions
JP2014022201A (en
Inventor
廣瀬 正幸
正幸 廣瀬
真山 修二
修二 真山
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Electric Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Industries Ltd
Priority to JP2012160020A priority Critical patent/JP5796783B2/en
Publication of JP2014022201A publication Critical patent/JP2014022201A/en
Application granted granted Critical
Publication of JP5796783B2 publication Critical patent/JP5796783B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Description

本発明は、導体の外周に複合紙(半合成絶縁紙)を用いた油浸絶縁層を具える複合紙ソリッドケーブルに関する。特に、安定した絶縁性能を有する複合紙ソリッドケーブルや生産性に優れる複合紙ソリッドケーブルに関するものである。   The present invention relates to a composite paper solid cable including an oil-immersed insulating layer using composite paper (semi-synthetic insulating paper) on the outer periphery of a conductor. In particular, the present invention relates to a composite paper solid cable having stable insulation performance and a composite paper solid cable excellent in productivity.

長距離の海底電力線路を構成する電力ケーブルとして、導体の外周に絶縁紙が巻回され、この絶縁紙層に絶縁油が含浸された油浸絶縁層を具える直流用ソリッドケーブルがある。絶縁紙には、従来、クラフト紙が利用されている。特許文献1では、絶縁紙として、クラフト紙と、ポリオレフィン系樹脂とを複合した複合紙(半合成絶縁紙)、例えば、PPLP(住友電気工業株式会社の登録商標)を利用することを提案している。   As a power cable constituting a long-distance submarine power line, there is a DC solid cable including an oil-impregnated insulating layer in which insulating paper is wound around the outer periphery of a conductor and the insulating paper layer is impregnated with insulating oil. Conventionally, kraft paper has been used as the insulating paper. Patent Document 1 proposes to use composite paper (semi-synthetic insulating paper) in which kraft paper and polyolefin resin are combined, for example, PPLP (registered trademark of Sumitomo Electric Industries, Ltd.) as insulating paper. Yes.

PPLP(登録商標)といった複合紙は、従来、OFケーブル用の絶縁紙として開発されたものである。OFケーブルは、複合紙を巻回してなる複合紙層に低粘度の絶縁油が常温で含浸され、運転時に絶縁油が加圧状態で使用される。そのため、OFケーブルは、安定した絶縁性能を得ることができる。   A composite paper such as PPLP (registered trademark) has been developed as an insulating paper for OF cables. In the OF cable, a composite paper layer formed by winding composite paper is impregnated with low-viscosity insulating oil at room temperature, and the insulating oil is used in a pressurized state during operation. Therefore, the OF cable can obtain stable insulation performance.

一方、従来のソリッドケーブルは、クラフト紙を巻回してなるクラフト紙層に高粘度の絶縁油が含浸され、運転時に絶縁油が加圧されない。そのため、運転時の温度変化に伴う絶縁油の体積変化に起因して、温度の低下時に負圧状態となり、ボイドといった絶縁油の欠乏空間が生じて絶縁性能が低下し得る。そこで、上記ボイドなどが生じても所望の絶縁性能を維持可能な電界(ストレス)を設定すると共に、運転時の温度上昇に伴って絶縁油の粘度が低下することで絶縁油が移動し、この移動により生じ得る欠陥を抑制するために絶縁油が所定の高粘度状態を維持できるように、従来のクラフト紙ソリッドケーブルは、最高使用温度を規定している。従来のクラフト紙ソリッドケーブルでは、運転時の電界がOFケーブルよりも小さく、運転温度も低い。   On the other hand, in the conventional solid cable, a kraft paper layer formed by winding kraft paper is impregnated with high-viscosity insulating oil, and the insulating oil is not pressurized during operation. Therefore, due to a change in volume of the insulating oil accompanying a change in temperature during operation, a negative pressure state occurs when the temperature drops, and a space deficient in insulating oil such as voids may be generated, resulting in a reduction in insulating performance. Therefore, while setting the electric field (stress) that can maintain the desired insulation performance even if the above-mentioned voids occur, the insulation oil moves as the viscosity of the insulation oil decreases as the temperature rises during operation. The conventional kraft paper solid cable defines a maximum use temperature so that the insulating oil can maintain a predetermined high viscosity state in order to suppress defects that may occur due to movement. In the conventional kraft paper solid cable, the electric field during operation is smaller than that of the OF cable, and the operation temperature is also low.

OFケーブルやソリッドケーブルのような油浸紙ケーブルでは、絶縁紙を所定のピッチで、かつ所定の隙間をあけて螺旋状に巻回し、ラジアル方向に積層させて絶縁紙層を形成する。より詳しくは、絶縁紙層は、絶縁紙の巻回方向が右巻の層と左巻の層とがラジアル方向に交互に積層されて構成される。上記隙間は、ケーブル製造時から線路運転時においてケーブルが受ける曲げ等の機械的履歴に対して、絶縁紙(ここでは複合紙)が動くためのスペースに相当する。上記隙間が無いと、絶縁紙が座屈したり、皺が生じたりし、上記隙間が広過ぎると、電気絶縁上の弱点となる。そのため、上記隙間の大きさは、ケーブル製造時に管理されている。   In an oil-immersed paper cable such as an OF cable or a solid cable, insulating paper is spirally wound at a predetermined pitch and with a predetermined gap, and is laminated in the radial direction to form an insulating paper layer. More specifically, the insulating paper layer is configured by alternately stacking a right-handed layer and a left-handed layer in the radial direction in the winding direction of the insulating paper. The gap corresponds to a space for the insulating paper (here, composite paper) to move with respect to a mechanical history such as bending that the cable receives during cable operation from the time of cable manufacture. Without the gap, the insulating paper buckles or wrinkles, and when the gap is too wide, it becomes a weak point in electrical insulation. Therefore, the size of the gap is managed at the time of cable manufacture.

ソリッドケーブルでは、絶縁紙層の外側から絶縁油が加圧含浸される。複合紙ソリッドケーブルでは、図3に示すように隙間gと複合紙30を構成するクラフト紙3bとで絶縁油の含浸経路を構築する。複合紙30を構成する樹脂3aは、絶縁油の流路を分断する。つまり、複合紙層では、樹脂3aによって複合紙層のラジアル方向の絶縁油の移動を抑制でき、脱油の影響を低減できる。そのため、複合紙ソリッドケーブルでは、運転時の電界や運転温度をOFケーブルと同等程度にまで高めることができ、送電容量の向上を図ることができると期待される。また、このような複合紙ソリッドケーブルは、既存のクラフト紙ソリッドケーブルに比較して、海底電力線路の小型化にも寄与すると期待される。なお、図3に示す黒破線矢印は、絶縁油の含浸方向を示す。   In the solid cable, the insulating oil is pressure impregnated from the outside of the insulating paper layer. In the composite paper solid cable, as shown in FIG. 3, an insulating oil impregnation path is constructed by the gap g and the kraft paper 3b constituting the composite paper 30. The resin 3a constituting the composite paper 30 divides the insulating oil flow path. That is, in the composite paper layer, the resin 3a can suppress the movement of the insulating oil in the radial direction of the composite paper layer, and the influence of deoiling can be reduced. Therefore, it is expected that the composite paper solid cable can increase the electric field and the operating temperature during operation to the same level as those of the OF cable, and can improve the transmission capacity. In addition, such a composite paper solid cable is expected to contribute to miniaturization of the submarine power line as compared with the existing kraft paper solid cable. Note that the black broken line arrows shown in FIG. 3 indicate the impregnation direction of the insulating oil.

複合紙に利用されるポリプロピレン(PP)などの樹脂の絶縁抵抗(体積抵抗率と等価)は、クラフト紙や絶縁油に比較して非常に大きい。また、直流電圧は抵抗分圧される。従って、直流用ソリッドケーブルの絶縁紙に複合紙を適用すると、直流電圧のほとんどを樹脂部分によって負担できる。この点から、複合紙ソリッドケーブルは、既存のクラフト紙ソリッドケーブルよりも耐電圧特性に優れる。   The insulation resistance (equivalent to volume resistivity) of resin such as polypropylene (PP) used for composite paper is very large compared to kraft paper and insulation oil. Further, the DC voltage is divided by resistance. Therefore, when composite paper is applied to the insulating paper of the DC solid cable, most of the DC voltage can be borne by the resin portion. From this point, the composite paper solid cable has better withstand voltage characteristics than the existing kraft paper solid cable.

特開平11-224546号公報Japanese Patent Laid-Open No. 11-224546

非常に長距離(例えば、数百km)に及ぶ大容量の海底電力線路を構築する場合、直流用ケーブルの適用が必須となる。そして、大容量の直流用ケーブルには、上述の複合紙ソリッドケーブルが適すると考えられる。また、運転時の許容温度の更なる向上が望まれることから、高温使用であっても、絶縁油の移動を抑制して、最も温度が上昇する導体近傍で脱油に伴う欠陥の形成を防止すること、即ち、導体近傍に絶縁油が常時存在して、安定した絶縁性能が得られることが望まれる。そのためには、温度が高くなる導体近傍に存在する絶縁油が高粘度であればよい。   When constructing a large-capacity submarine power line that extends over a very long distance (for example, several hundred km), it is essential to use a DC cable. The above-described composite paper solid cable is considered suitable for a large-capacity DC cable. In addition, since further improvement of the allowable temperature during operation is desired, even when used at high temperatures, the movement of insulating oil is suppressed to prevent the formation of defects associated with deoiling near the conductor where the temperature rises the most. That is, it is desired that insulating oil always exists in the vicinity of the conductor to obtain a stable insulating performance. For that purpose, the insulating oil which exists in the vicinity of the conductor where temperature rises should just be high viscosity.

例えば、高粘度の絶縁油を複合紙ソリッドケーブルに適用することが考えられる。しかし、この場合、上述のように複合紙における樹脂部分が絶縁油の流路を分断することによって、複合紙層への絶縁油の含浸期間が長期化し易く、生産性の低下を招く恐れがある。また、上述の分断によって、含浸の不良箇所が生じ得る恐れもある。   For example, it is conceivable to apply a high viscosity insulating oil to a composite paper solid cable. However, in this case, as described above, the resin portion in the composite paper breaks the flow path of the insulating oil, so that the period of impregnation of the insulating oil into the composite paper layer is likely to be prolonged, and the productivity may be reduced. . Moreover, there is a possibility that a defective portion of impregnation may occur due to the above-mentioned division.

複合紙の樹脂として、絶縁油の含浸によって樹脂の厚さが増加する膨潤特性を有するものが用いられる場合がある。膨潤特性は、絶縁油中の低分子量成分(絶縁油の分子量分布をとったとき、分子量が低い側の成分)が上記樹脂に吸収されることで生じる特性であることが知られている。上述のように絶縁紙層の外側から絶縁油が含浸されるソリッドケーブルに対して、絶縁紙に、上記膨潤特性を有する樹脂を含む複合紙を用いると、含浸過程の初期の絶縁油(先頭の絶縁油)は、複合紙層の外周側領域を構成する複合紙(以下、外側複合紙と呼ぶ)中の樹脂に接触することで、絶縁油中の低分子量成分が上記樹脂に吸収されて徐々に減じられ、高分子量成分の割合が相対的に高まり、粘度が上昇する(増粘する)。そして、増粘した絶縁油が導体側に向かう(含浸していく)。この含浸過程では、順次、低分子量成分が減じられていない絶縁油(以下、フレッシュな油と呼ぶ)が複合紙層の外側から供給されて、外側複合紙は常にフレッシュな油が接触して膨潤し、絶縁油の増粘が生じる。フレッシュな油が常に接触し得る外側複合紙は、含浸過程の早い段階で所定の膨潤が完了し、膨潤完了後にフレッシュな油が接触しても膨潤は進行せず、絶縁油の増粘も生じ無い。増粘した絶縁油とフレッシュな油とがある程度混ざり合いながら複合紙層の導体側に絶縁油が含浸される。そのため、複合紙層の導体側領域に含浸された絶縁油の粘度は、順次供給される絶縁油(フレッシュな油)よりも高くなる。そして、絶縁油の含浸後、油浸絶縁層に含浸された絶縁油は、フレッシュな油の粘度に対して、外周側から導体側に向かって粘度が高い。   As the resin of the composite paper, there is a case where a resin having a swelling characteristic that the thickness of the resin increases by impregnation with insulating oil is used. It is known that the swelling characteristic is a characteristic that occurs when a low molecular weight component in insulating oil (a component having a lower molecular weight when the molecular weight distribution of insulating oil is taken) is absorbed by the resin. When the composite paper containing the resin having the swelling property is used as the insulating paper for the solid cable impregnated with the insulating oil from the outside of the insulating paper layer as described above, the insulating oil at the initial stage of the impregnation process (leading Insulating oil) is gradually brought into contact with the resin in the composite paper (hereinafter referred to as the outer composite paper) constituting the outer peripheral side region of the composite paper layer, so that the low molecular weight component in the insulating oil is absorbed by the resin. The ratio of the high molecular weight component is relatively increased and the viscosity is increased (increased). Then, the thickened insulating oil goes to the conductor side (impregnation). In this impregnation process, insulating oil (hereinafter referred to as “fresh oil”) in which low molecular weight components have not been reduced is sequentially supplied from the outside of the composite paper layer, and the outer composite paper is always swollen by contact with the fresh oil. And thickening of the insulating oil occurs. The outer composite paper that can always come into contact with fresh oil completes the specified swelling early in the impregnation process, and does not progress even if the fresh oil comes into contact after the completion of swelling, resulting in thickening of the insulating oil. No. The insulating oil is impregnated on the conductor side of the composite paper layer while the thickened insulating oil and fresh oil are mixed to some extent. Therefore, the viscosity of the insulating oil impregnated in the conductor side region of the composite paper layer is higher than the insulating oil (fresh oil) that is sequentially supplied. After the impregnation with the insulating oil, the insulating oil impregnated in the oil-immersed insulating layer has a higher viscosity from the outer peripheral side to the conductor side than the fresh oil viscosity.

一方、複合紙の膨潤特性が示す通り、絶縁油において複合紙層中の樹脂が吸収する低分子量成分の量は、含浸温度によって変化するものの、有限である。そのため、複合紙層の導体側領域を構成する複合紙(以下、導体側複合紙と呼ぶ)は、外側複合紙を経ることで低分子量成分が減じられた絶縁油が接触することから、導体側複合紙が膨潤することは実質的に無い。このように複合紙ソリッドケーブルでは、絶縁油の含浸過程において、導体側複合紙の近傍に含浸される絶縁油は、上述のようにフレッシュな油よりも高い粘度になるものの、この増粘は、外側複合紙の膨潤特性によって生じ得るものであり、導体側複合紙自体の膨潤特性の寄与は小さい。以上のことから、導体及びその近傍に存在する絶縁油をより増粘可能な構成の開発、つまり、導体側複合紙における絶縁油の増粘への寄与の増大が望まれる。   On the other hand, as the swelling property of the composite paper shows, the amount of the low molecular weight component absorbed by the resin in the composite paper layer in the insulating oil is finite although it varies depending on the impregnation temperature. Therefore, the composite paper constituting the conductor side region of the composite paper layer (hereinafter referred to as the conductor side composite paper) comes into contact with the insulating oil whose low molecular weight component has been reduced through the outer composite paper. There is virtually no swelling of the composite paper. Thus, in the composite paper solid cable, the insulating oil impregnated in the vicinity of the conductor-side composite paper in the impregnation process of the insulating oil has a higher viscosity than the fresh oil as described above. This may be caused by the swelling characteristics of the outer composite paper, and the contribution of the swelling characteristics of the conductor-side composite paper itself is small. From the above, it is desired to develop a structure capable of thickening the conductor and the insulating oil existing in the vicinity thereof, that is, to increase the contribution to the thickening of the insulating oil in the conductor-side composite paper.

本発明は、上記事情を鑑みてなされたものであり、本発明の目的は、高温使用においても、より安定した絶縁性能を有する複合紙ソリッドケーブルや生産性に優れる複合紙ソリッドケーブルを提供することにある。   The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composite paper solid cable having more stable insulation performance even in high temperature use and a composite paper solid cable excellent in productivity. It is in.

上述のように油浸絶縁層を形成する複合紙層の導体側領域では、ある程度増粘した絶縁油が含浸されるものの、導体側複合紙の実際の膨潤量は小さい。複合紙層の外周側領域では、絶縁油の粘度は概ね含浸する絶縁油(フレッシュな油)の粘度であるものの、外側複合紙の膨潤量は、所定の膨潤特性に応じたものになる(外側複合紙の膨潤特性に相当する膨潤量を示す)。このことから、樹脂の膨潤特性に差がある複数の複合紙を用いて複合紙層を構成すれば、複合紙層の導体側領域に存在する絶縁油をより効果的に増粘できるといえる。   As described above, the conductor-side region of the composite paper layer forming the oil-immersed insulating layer is impregnated with insulating oil thickened to some extent, but the actual amount of swelling of the conductor-side composite paper is small. In the outer peripheral region of the composite paper layer, the viscosity of the insulating oil is roughly the viscosity of the impregnated insulating oil (fresh oil), but the amount of swelling of the outer composite paper depends on the predetermined swelling characteristics (outside The amount of swelling corresponding to the swelling property of the composite paper is shown). From this, it can be said that if the composite paper layer is constituted by using a plurality of composite papers having different resin swelling characteristics, the insulating oil existing in the conductor side region of the composite paper layer can be thickened more effectively.

そこで、本発明は、複合紙を構成する樹脂の膨潤に着目して、樹脂の膨潤特性(膨潤量)が異なる複合紙を用いた複合紙層を具えることを提案する。   In view of this, the present invention focuses on the swelling of the resin constituting the composite paper, and proposes to provide a composite paper layer using composite paper having different resin swelling characteristics (swelling amount).

本発明の複合紙ソリッドケーブルは、樹脂とクラフト紙とが積層一体化された複合紙が導体の外周に巻回されてなる複合紙層に、絶縁油が含浸された油浸絶縁層を具える。この複合紙ソリッドケーブルは、上記複合紙に絶縁油を含浸させる前後における上記樹脂の厚さの変化率を膨潤指標とするとき、上記油浸絶縁層において導体側領域を構成する複合紙の膨潤指標が、上記油浸絶縁層において外周側領域を構成する複合紙の膨潤指標よりも大きい。   The composite paper solid cable of the present invention includes an oil immersion insulating layer in which insulating paper is impregnated with a composite paper layer in which a composite paper in which resin and kraft paper are laminated and integrated is wound around the outer periphery of a conductor. . This composite paper solid cable has a swelling index of the composite paper constituting the conductor-side region in the oil-immersed insulating layer when the change rate of the thickness of the resin before and after the composite paper is impregnated with the insulating oil is used as a swelling index. However, it is larger than the swelling index of the composite paper constituting the outer peripheral side region in the oil-immersed insulating layer.

膨潤特性が異なる複合紙を用いた複合紙層を具えることで、複合紙層の外周側領域を構成する複合紙:外側複合紙の樹脂が吸収しなかった絶縁油の成分中に、複合紙層の導体側領域を構成する複合紙:導体側複合紙の樹脂が吸収して膨潤し得る低分子量成分が存在し得る。この低分子量成分が導体側複合紙の樹脂に吸収されることで、導体近傍で、絶縁油の粘度をより効果的に向上できる。従って、本発明の複合紙ソリッドケーブルは、導体近傍の絶縁油の粘度を高められ、運転時に高温になっても絶縁油の移動や、移動によって生じ得る欠陥を抑制できる。そのため、本発明の複合紙ソリッドケーブルは、長期に亘り、安定した絶縁性能を有することができ、絶縁性能の信頼性を高められる。また、本発明の複合紙ソリッドケーブルは、運転温度を更に高くした場合でも、安定した性能を維持することができる。更に、本発明の複合紙ソリッドケーブルは、特に、導体側複合紙が膨潤することで径方向に隣り合う複合紙間を密着させることができる。このことからも、本発明の複合紙ソリッドケーブルは、絶縁油の移動を抑制でき、高温になっても、導体近傍に絶縁油が十分に存在した状態を維持できる。   Composite paper that composes the outer peripheral area of the composite paper layer by providing a composite paper layer using composite paper with different swelling characteristics: Composite paper in the component of insulating oil that the resin of the outer composite paper did not absorb Composite paper constituting the conductor side region of the layer: There may be a low molecular weight component that can be absorbed and swollen by the resin of the conductor side composite paper. This low molecular weight component is absorbed by the resin of the conductor-side composite paper, so that the viscosity of the insulating oil can be more effectively improved in the vicinity of the conductor. Therefore, the composite paper solid cable of the present invention can increase the viscosity of the insulating oil in the vicinity of the conductor and suppress the movement of the insulating oil and defects that may be caused by the movement even when the temperature becomes high during operation. Therefore, the composite paper solid cable of the present invention can have a stable insulation performance over a long period of time, and the reliability of the insulation performance can be enhanced. Further, the composite paper solid cable of the present invention can maintain stable performance even when the operating temperature is further increased. Furthermore, especially the composite paper solid cable of this invention can closely_contact | adhere between the composite papers which adjoin a radial direction because a conductor side composite paper swells. Also from this, the composite paper solid cable of the present invention can suppress the movement of the insulating oil, and can maintain the state in which the insulating oil is sufficiently present in the vicinity of the conductor even at a high temperature.

本発明の複合紙ソリッドケーブルでは、導体側複合紙に含浸される絶縁油が増粘される効果を見込み、含浸する絶縁油(フレッシュな油)の粘度をその分だけ低くすることもできる。この場合、含浸に要する期間を効果的に短縮できる。また、絶縁油の粘度を低くすることで、含浸温度を下げることもできる。この場合、絶縁紙に対する熱履歴の低減、及び絶縁油の含浸後の冷却に要する期間の短縮を図ることができる。このように本発明の複合紙ソリッドケーブルは、生産性に優れる構成とすることもできる。   In the composite paper solid cable of the present invention, it is possible to increase the viscosity of the insulating oil impregnated in the conductor-side composite paper, and the viscosity of the impregnating insulating oil (fresh oil) can be lowered accordingly. In this case, the period required for impregnation can be effectively shortened. Moreover, the impregnation temperature can be lowered by lowering the viscosity of the insulating oil. In this case, it is possible to reduce the thermal history of the insulating paper and shorten the period required for cooling after impregnation with the insulating oil. Thus, the composite paper solid cable of this invention can also be set as the structure excellent in productivity.

本発明の複合紙ソリッドケーブルは、上記導体側領域を構成する複合紙の上記膨潤指標、及びこの複合紙に占める樹脂の割合の双方を、上記外周側領域を構成する複合紙の上記膨潤指標、及びこの複合紙に占める樹脂の割合よりも大きい構成とすることができる。   In the composite paper solid cable of the present invention, both the swelling index of the composite paper constituting the conductor-side region, and the ratio of the resin occupying the composite paper, the swelling index of the composite paper constituting the outer peripheral region, And it can be set as the structure larger than the ratio of the resin which occupies for this composite paper.

上記構成は、導体側複合紙が吸収する低分子量成分を外側複合紙よりも相対的に多くでき、導体側複合紙の樹脂量に比例して絶縁油の更なる増粘や樹脂の膨潤が期待できる。   The above configuration allows the conductor-side composite paper to absorb relatively low molecular weight components more than the outer composite paper, and is expected to further increase the viscosity of the insulating oil and swell the resin in proportion to the resin amount of the conductor-side composite paper. it can.

本発明の複合紙ソリッドケーブルは、上記油浸絶縁層の外周側から導体側に向かって、連続的に又は段階的に上記複合紙の膨潤指標が大きい構成とすることができる。   The composite paper solid cable of the present invention can be configured such that the swelling index of the composite paper is large continuously or stepwise from the outer peripheral side of the oil-immersed insulating layer to the conductor side.

上記構成は、膨潤指標が細かく異なっていることで、外周側から導体側に向かって、絶縁油の増粘を緻密に行えると期待される。   The above configuration is expected to be able to densely thicken the insulating oil from the outer peripheral side to the conductor side because the swelling index is finely different.

本発明の複合紙ソリッドケーブルにおいて、上記複合紙は、ポリオレフィン系樹脂とクラフト紙とが積層一体化されたものとすることができる。   In the composite paper solid cable of the present invention, the composite paper may be a laminate-integrated polyolefin resin and kraft paper.

上記複合紙は、絶縁特性に優れる複合紙を具えることで、小型化、大容量化に寄与することができる。   The composite paper can contribute to size reduction and capacity increase by including composite paper having excellent insulating properties.

本発明の複合紙ソリッドケーブルにおいて、上記複合紙は、ポリプロピレン層の両面にクラフト紙が積層一体化されたものとすることができる。   In the composite paper solid cable of the present invention, the composite paper may be one in which kraft paper is laminated and integrated on both sides of a polypropylene layer.

この場合、PPLP(登録商標)に代表される絶縁特性に優れる複合紙を具えることから、絶縁層の厚さを薄くでき、ケーブル径を小さくできる上に、運転時の最高到達温度を高められ、大容量化が可能である。   In this case, the composite paper excellent in insulation characteristics represented by PPLP (registered trademark) is provided, so that the thickness of the insulation layer can be reduced, the cable diameter can be reduced, and the maximum temperature during operation can be increased. The capacity can be increased.

本発明の複合紙ソリッドケーブルは、直流送電に用いることができる。   The composite paper solid cable of the present invention can be used for direct current power transmission.

この場合、絶縁抵抗の高い複合紙層の樹脂部分が主として直流電圧を負担し、絶縁油の電界を低減すると共に、絶縁油の移動を抑制して脱油の影響を低減できる。従って、この複合紙ソリッドケーブルは、長距離海底電力線路の構成部材に好適に利用できる。   In this case, the resin portion of the composite paper layer having a high insulation resistance mainly bears a DC voltage, reduces the electric field of the insulating oil, and suppresses the movement of the insulating oil, thereby reducing the influence of deoiling. Therefore, this composite paper solid cable can be suitably used as a constituent member of a long-distance submarine power line.

本発明の複合紙ソリッドケーブルは、より安定した絶縁性能を有したり、生産性に優れたりすることができる。   The composite paper solid cable of the present invention can have more stable insulation performance and can be excellent in productivity.

実施形態1の複合紙ソリッドケーブルの概略を示す断面図である。FIG. 2 is a cross-sectional view illustrating an outline of a composite paper solid cable according to the first embodiment. 実施形態2の複合紙ソリッドケーブルの概略を示す断面図である。6 is a cross-sectional view schematically showing a composite paper solid cable of Embodiment 2. FIG. 複合紙が巻回されてラジアル方向に積層された複合紙層において、絶縁油の含浸経路を説明する説明図である。It is explanatory drawing explaining the impregnation path | route of insulating oil in the composite paper layer by which the composite paper was wound and was laminated | stacked in the radial direction.

以下、図面を適宜参照して、本発明の実施の形態を説明する。   Embodiments of the present invention will be described below with reference to the drawings as appropriate.

[実施形態1]
(全体構成)
図1に示す実施形態1の複合紙ソリッドケーブル1Aは、基本的構成は従来のクラフト紙ソリッドケーブルと同様である。代表的には、中心から順に導体11、内部半導電層12、油浸絶縁層13A、外部半導電層14を具えるケーブルコアを具える。ケーブルコアは金属シース15に収納されている。金属シース15の外周には、防食層16、更にその外周には鉄線鎧装(図示せず)が形成される。金属シース15上、又は防食層16上にステンレステープなどで構成した補強層(図示せず)を具える形態とすることができる。
[Embodiment 1]
(overall structure)
The basic configuration of the composite paper solid cable 1A of Embodiment 1 shown in FIG. 1 is the same as that of a conventional kraft paper solid cable. Typically, a cable core including a conductor 11, an inner semiconductive layer 12, an oil immersion insulating layer 13A, and an outer semiconductive layer 14 in order from the center is provided. The cable core is housed in a metal sheath 15. An anticorrosion layer 16 is formed on the outer periphery of the metal sheath 15, and an iron wire armor (not shown) is formed on the outer periphery thereof. The metal sheath 15 or the anticorrosion layer 16 may be provided with a reinforcing layer (not shown) made of stainless steel tape or the like.

油浸絶縁層13Aは、絶縁紙を巻回してなる絶縁紙層130Aと、この絶縁紙層130Aに含浸された絶縁油とから構成される。特に、複合紙ソリッドケーブル1Aでは、絶縁紙として、樹脂300とクラフト紙310とが積層一体化された複合紙(半合成絶縁紙)を用いる。   The oil immersion insulating layer 13A is composed of an insulating paper layer 130A formed by winding insulating paper, and an insulating oil impregnated in the insulating paper layer 130A. In particular, the composite paper solid cable 1A uses a composite paper (semi-synthetic insulating paper) in which the resin 300 and the kraft paper 310 are laminated and integrated as the insulating paper.

複合紙ソリッドケーブル1Aは、代表的には、以下のようにして製造する。導体11の外周に、内部半導電層12、絶縁紙層130A、外部半導電層14を順に形成し、ケーブルコアを作製する。絶縁紙層130Aは、所望の仕様(膨潤指標(後述)、材質、複合紙の厚さ、複合紙の厚さに対する樹脂300の割合など)であってテープ状にした複合紙を所定のピッチで、かつ所定の隙間g(図3参照)を設けて巻回して形成する。得られたケーブルコアをタンク内に巻き取って、コア中の水分や空気などを除去するために真空中で加熱乾燥する。この乾燥後、所望の特性の絶縁油をタンク内に充填して所定の含浸温度にして、絶縁紙層130Aに加圧含浸する。絶縁油の含浸後に所定の温度に冷却した後、この油浸絶縁層13Aを具えるケーブルコアの上に金属シース15、防食層16、鉄線鎧装などを順に形成する。   The composite paper solid cable 1A is typically manufactured as follows. An inner semiconductive layer 12, an insulating paper layer 130A, and an outer semiconductive layer 14 are formed in this order on the outer periphery of the conductor 11 to produce a cable core. The insulating paper layer 130A has a desired specification (swelling index (described later), material, thickness of the composite paper, ratio of the resin 300 to the thickness of the composite paper, etc.) and tape-like composite paper at a predetermined pitch. And a predetermined gap g (see FIG. 3) is provided and wound. The obtained cable core is wound into a tank and heated and dried in a vacuum in order to remove moisture, air, etc. in the core. After this drying, the insulating paper layer 130A is impregnated under pressure by filling the tank with insulating oil having desired characteristics to a predetermined impregnation temperature. After impregnation with insulating oil and cooling to a predetermined temperature, a metal sheath 15, an anticorrosion layer 16, an iron wire armor, and the like are sequentially formed on the cable core having the oil immersion insulating layer 13A.

そして、複合紙ソリッドケーブル1Aは、膨潤指標が異なる複数の複合紙によって絶縁紙層(複合紙層)130Aが構成されていることを最大の特徴とする。具体的には、複合紙層における導体11の近傍の領域:導体側領域13iを構成する複合紙30Aiは、金属シース15寄りの領域:外周側領域13oを構成する複合紙30Aoよりも膨潤指標が大きい。ここでは、膨潤指標が異なる二種類の複合紙30Ai,30Aoによって複合紙層を構成している。   The composite paper solid cable 1A is characterized in that an insulating paper layer (composite paper layer) 130A is composed of a plurality of composite papers having different swelling indices. Specifically, in the composite paper layer, the area near the conductor 11: the composite paper 30Ai constituting the conductor-side area 13i has a swelling index larger than the area near the metal sheath 15: the composite paper 30Ao constituting the outer peripheral area 13o. large. Here, the composite paper layer is composed of two types of composite papers 30Ai and 30Ao having different swelling indices.

(油浸絶縁層)
<複合紙>
複合紙30Ai,30Aoの基本的な構成は同様である。樹脂300(300i,300o)は、ポリオレフィン系樹脂が代表的である。ポリオレフィン系樹脂は、ポリプロピレン:PP、ポリエチレン:PE、ポリメチルペンテン:PMPなどが挙げられる。特に、PPは、絶縁特性に優れる。クラフト紙310(311i,312i,311o,312o)は、絶縁層に利用されている公知のものを利用できる。
(Oil-immersion insulation layer)
<Composite paper>
The basic configuration of the composite papers 30Ai and 30Ao is the same. The resin 300 (300i, 300o) is typically a polyolefin resin. Examples of the polyolefin resin include polypropylene: PP, polyethylene: PE, and polymethylpentene: PMP. In particular, PP has excellent insulating properties. As the kraft paper 310 (311i, 312i, 311o, 312o), a known paper used for an insulating layer can be used.

複合紙30Ai,30Aoの形態は、樹脂300からなる樹脂層の一面にのみクラフト紙310がラミネートされた(積層一体化された)形態、樹脂層の両面にクラフト紙310がラミネートされた(積層一体化された)形態が挙げられる。ポリオレフィン系樹脂を具える複合紙として、ポリプロピレン層の両面にクラフト紙が積層された構造であるPPLP(登録商標)が好適に利用できる。   The forms of composite paper 30Ai and 30Ao are a form in which kraft paper 310 is laminated only on one side of the resin layer made of resin 300 (laminated and integrated), and kraft paper 310 is laminated on both sides of the resin layer (laminated and integrated) Form). PPLP (registered trademark) having a structure in which kraft paper is laminated on both sides of a polypropylene layer can be suitably used as a composite paper comprising a polyolefin resin.

複合紙30Ai,30Aoの厚さは、70μm以上200μm以下が実用的であり、80μm〜150μmが好ましい。複合紙30Ai,30Aoの厚さ:Ttotalにおける樹脂300i,300oの厚さ:TRの割合:TR/Ttotal(以下、この割合をk値と呼ぶ)は、適宜選択することができ、0.4〜0.8程度が利用し易い。 The thickness of the composite paper 30Ai, 30Ao is practically 70 μm or more and 200 μm or less, and preferably 80 μm to 150 μm. Composite paper 30ai, the thickness of the 30Ao: T resin in total 300i, the 300o thickness: the ratio of T R: T R / T total ( hereinafter, referred to as the ratio between k value) may be appropriately selected, About 0.4 to 0.8 is easy to use.

ここでは、複合紙30Ai,30Aoの厚さを等しくしているが、異ならせることもできる。また、ここでは、複合紙30Ai,30Aoのk値を等しくしているが、異ならせることもできる(実施形態2参照)。複合紙30Ai,30Aoの厚さ及びk値を等しくすると、巻回条件などを調整し易く、製造性に優れる。   Here, the thicknesses of the composite papers 30Ai and 30Ao are equal, but may be different. Further, here, the k values of the composite papers 30Ai and 30Ao are made equal, but can be made different (see Embodiment 2). When the thicknesses and k values of the composite papers 30Ai and 30Ao are made equal, the winding conditions and the like can be easily adjusted and the productivity is excellent.

<絶縁油>
絶縁油は、例えば、60℃における動粘度が500mm2/s(500cst)以上の高粘度油、60℃における動粘度が10mm2/s(10cst)以上500mm2/s(500cst)未満である中粘度油などが挙げられる。具体的には、ナフテン系油(例えば、H&R社製商品名:T-2015)、ポリスチレン系絶縁油、鉱油、アルキルベンゼンやポリブデン系の合成油、及び重質アルキレートから選択される1種、又は、これら2種以上の混合油などが挙げられる。絶縁油は、粘度や膨潤指標、その他、経済性や供給性などを考慮して選択することができる。
<Insulating oil>
Among insulating oil, for example, 60 kinematic viscosity at ° C. is 500mm 2 / s (500cst) or high viscosity oil, kinematic viscosity at 60 ° C. is less than 10mm 2 / s (10cst) or 500mm 2 / s (500cst) Viscosity oil etc. are mentioned. Specifically, one kind selected from naphthenic oil (for example, trade name: T-2015 manufactured by H & R), polystyrene insulating oil, mineral oil, alkylbenzene or polybuden synthetic oil, and heavy alkylate, or And a mixture of two or more of these. The insulating oil can be selected in consideration of viscosity, swelling index, economic efficiency, supply ability, and the like.

<膨潤指標>
膨潤指標とは、ここでは、複合紙に絶縁油を含浸させる前後における樹脂の厚さの変化率とする。膨潤指標は、樹脂内に絶縁油が含浸されることによる厚さの変化のみを対象とし、温度変化などに起因する厚さの変化などは排除する。具体的には、以下のように測定する。
<Swelling index>
Here, the swelling index is defined as the rate of change in resin thickness before and after impregnating the composite paper with insulating oil. The swelling index covers only a change in thickness due to the resin impregnated with insulating oil, and excludes a change in thickness caused by a temperature change or the like. Specifically, the measurement is performed as follows.

複合紙のクラフト紙部分を除去した樹脂の質量を樹脂の比重で除した値(体積)を求め、この除した値(体積)を単位面積あたりに換算した値(体積/面積)を初期の樹脂の厚さ:Tcとする。また、設定した含浸温度で絶縁油をこの樹脂に含浸して膨潤させる前後の樹脂の厚さ変化(膨潤後の樹脂の厚さと膨潤前の樹脂の厚さとの差)を膨潤による厚さ変化:Tppとする。   Obtain the value (volume) obtained by dividing the mass of the resin from which the kraft paper part of the composite paper was removed by the specific gravity of the resin, and the value (volume / area) obtained by converting this divided value (volume) per unit area (initial volume) Thickness: Tc. In addition, the resin thickness change before and after the resin is impregnated and swollen with insulating oil at the set impregnation temperature (the difference between the thickness of the resin after swelling and the thickness of the resin before swelling) is the thickness change due to swelling: Tpp.

上述のk値が分かっている場合、k値と複合紙の厚さとを利用して、初期の樹脂の厚さ:Tcを求めることができる。具体的には、初期の樹脂の厚さ:Tcは、絶縁油の含浸前における複合紙の厚さ:Tctotalとk値との積:Tctotal×kによって求められる。 When the k value is known, the initial resin thickness: Tc can be obtained by using the k value and the thickness of the composite paper. Specifically, the initial resin thickness: Tc is determined by the thickness of the composite paper before impregnation with the insulating oil: product of Tc total and k value: Tc total × k.

初期の樹脂の厚さ:Tc及び絶縁油の含浸前後の厚さ変化:Tppの測定はいずれも、対象を1枚のみとしてもよいし、複数枚とし、複数枚の積層体の厚さを測定し、1枚あたりの厚さに換算してもよい。複数枚の積層体の厚さを測定する場合、厚さの変化の絶対値が1枚のときよりも大きくなることから、測定対象の厚さの測定が行い易く、かつ平均的な厚さを測定できる傾向にあることから、測定誤差を低減できると期待される。   Initial resin thickness: Tc and thickness change before and after impregnation with insulating oil: Tpp measurement can be either single target or multiple sheets, and measure the thickness of multiple laminates However, it may be converted into the thickness per sheet. When measuring the thickness of multiple laminates, the absolute value of the change in thickness is greater than when one sheet is used, making it easier to measure the thickness of the object being measured and the average thickness. Since there is a tendency to measure, it is expected that measurement errors can be reduced.

特に、上記含浸前後の厚さ変化は、複合紙の状態で測定することが合理的である。この場合、含浸前後の厚さ変化の測定は、代表的には、一定の荷重を複合紙に印加した状態で行う。ここで、荷重を印加した状態で複合紙の乾燥を行うと、複合紙中のクラフト紙において乾燥に起因する厚さ変化が生じる。この後に絶縁油の含浸を行うと、絶縁油の含浸前後でクラフト紙の厚さが実質的に変化しない。従って、クラフト紙の厚さの変化を伴わない樹脂のみの厚さ変化の測定を行える。   In particular, it is reasonable to measure the thickness change before and after the impregnation in the state of composite paper. In this case, the thickness change before and after the impregnation is typically measured in a state where a certain load is applied to the composite paper. Here, when the composite paper is dried in a state where a load is applied, a thickness change caused by the drying occurs in the kraft paper in the composite paper. If impregnation with insulating oil is performed thereafter, the thickness of the kraft paper does not substantially change before and after the impregnation with insulating oil. Therefore, it is possible to measure the thickness change of only the resin without any change in the thickness of the kraft paper.

上述のようにして求めた初期の樹脂の厚さTc及び含浸前後の厚さ変化:Tppを用いて、膨潤指標は、(Tpp/Tc)×100(%)とする。   Using the initial resin thickness Tc and thickness change before and after impregnation: Tpp determined as described above, the swelling index is (Tpp / Tc) × 100 (%).

膨潤指標は、上述のように使用する複合紙に含まれる樹脂そのものの特性とすべきであり、含浸する絶縁油の種類、含浸温度に依存するものであって、乾燥温度と含浸温度との差に基づく熱膨張による厚さ変化を含めることは、合理的ではないと考えられる。また、膨潤指標の測定時における作業性の向上も考慮すると、膨潤指標は、乾燥温度と含浸温度とを同じ温度として測定することが好ましい、といえる。そこで、膨潤指標は、基本的には、絶縁油の含浸前後の温度を同じにして測定して、温度変化による熱膨張の影響(厚さの変化など)を含まないものとする。乾燥温度と絶縁油の含浸温度とが異なる場合には、熱膨張分を考慮して、この含浸温度における絶縁油の含浸前の厚さを換算して、膨潤指標を算出する。   The swelling index should be a property of the resin itself contained in the composite paper used as described above, and depends on the type of insulating oil to be impregnated, the impregnation temperature, and the difference between the drying temperature and the impregnation temperature. Inclusion of thickness changes due to thermal expansion based on is considered unreasonable. Further, considering the improvement in workability at the time of measuring the swelling index, it can be said that the swelling index is preferably measured by setting the drying temperature and the impregnation temperature to the same temperature. Therefore, the swelling index is basically measured with the temperature before and after impregnation with the insulating oil being the same, and does not include the influence of thermal expansion (such as a change in thickness) due to a temperature change. When the drying temperature is different from the impregnation temperature of the insulating oil, the swelling index is calculated by converting the thickness of the impregnation temperature before impregnation with the insulating oil in consideration of the thermal expansion.

膨潤指標を測定するときの絶縁油と、実際に製造する複合紙ソリッドケーブルに用いる絶縁油とは、異なったものとすることができる。また、膨潤指標を測定するときの絶縁油の含浸温度は、実際のケーブルの含浸条件に応じて変更してもよい。代表的には、膨潤指標は、高い含浸温度で測定する。膨潤指標の測定に、例えば、上述のT-2015を利用することができる。膨潤指標の測定にT-2015を用いた場合、種々の絶縁油の中でも膨潤指標の値が比較的大きくなる傾向にある。膨潤指標の測定にあたり、含浸温度を高くすると樹脂が膨潤し易くなり、膨潤指標の値が大きくなる傾向にある。このように膨潤指標が高くなる油種を用いたり、含浸温度を高くしたりする手法は、膨潤指標の異同を確認し易い。そのため、これらの手法は、複合紙を構成する樹脂の膨潤特性の管理に有用である。例えば、以下の(1)〜(3)のいずれか一つを利用して膨潤指標を測定し、以下の(I)〜(III)のいずれか一つを利用して、実際のケーブルの膨潤指標を管理することができる。(1)T-2015などの膨潤量の大きい絶縁油を使用する、(2)含浸温度を高くする、又は(3)これらの組み合わせとする。(I)実際のケーブルの含浸温度を膨潤指標を測定した含浸温度よりも低くする、(II)実際のケーブルでは膨潤指標を測定した絶縁油よりも膨潤量が小さい絶縁油を利用する、又は(III)これらの組み合わせとする。また、測定した膨潤指標の値を利用することで、実際のケーブルの製造条件についての膨潤指標の管理の精度を高められる。更に、膨潤指標の管理精度を高めることで、例えば、(所定の管理範囲内において)膨潤指標が小さい製造ロット品を外側複合紙30Aoに、膨潤指標が大きい製造ロット品を導体側複合紙30Aiに適用することができる。この場合、絶縁紙層130Aの導体側に向かって、より緻密に絶縁油の増粘を行えると期待できる。   The insulating oil used for measuring the swelling index and the insulating oil used for the composite paper solid cable actually manufactured can be different. Further, the impregnation temperature of the insulating oil when measuring the swelling index may be changed according to the actual impregnation condition of the cable. Typically, the swelling index is measured at a high impregnation temperature. For example, T-2015 described above can be used for measurement of the swelling index. When T-2015 is used for the measurement of the swelling index, the value of the swelling index tends to be relatively large among various insulating oils. In the measurement of the swelling index, if the impregnation temperature is increased, the resin tends to swell and the value of the swelling index tends to increase. Thus, the method of using an oil type with a high swelling index or increasing the impregnation temperature makes it easy to confirm the difference between the swelling indices. Therefore, these methods are useful for managing the swelling characteristics of the resin constituting the composite paper. For example, the swelling index is measured using any one of the following (1) to (3), and the actual cable is swollen using any one of the following (I) to (III): Indicators can be managed. (1) Use an insulating oil with a large swelling amount such as T-2015, (2) increase the impregnation temperature, or (3) a combination thereof. (I) The impregnation temperature of the actual cable is made lower than the impregnation temperature measured for the swelling index, (II) In the actual cable, the insulating oil whose swelling amount is smaller than the insulating oil whose swelling index is measured is used, or ( III) A combination of these. In addition, by using the measured value of the swelling index, the accuracy of management of the swelling index with respect to the actual cable manufacturing conditions can be increased. Further, by increasing the management accuracy of the swelling index, for example, a production lot product with a small swelling index (within a predetermined management range) is assigned to the outer composite paper 30Ao, and a production lot product with a large swelling index is assigned to the conductor-side composite paper 30Ai. Can be applied. In this case, it can be expected that the insulating oil can be thickened more densely toward the conductor side of the insulating paper layer 130A.

膨潤指標の測定に用いる絶縁油と、実際に製造する複合紙ソリッドケーブルに用いる絶縁油とを同じものとすると、測定した膨潤指標の値は、そのまま実際のケーブルの値となる。従って、この形態は、実際のケーブルの膨潤指標を簡単に把握することができる。   If the insulating oil used for the measurement of the swelling index is the same as the insulating oil used for the composite paper solid cable actually manufactured, the measured value of the swelling index is the value of the actual cable as it is. Therefore, this form can easily grasp the actual swelling index of the cable.

複合紙30Ai,30Aoの膨潤指標の値(絶対値)は、適宜設定することができる。膨潤指標は、複合紙を構成する樹脂の仕様(樹脂の結晶化度など)、絶縁油の材質、含浸温度などで変化する。なお、膨潤は、樹脂の非結晶部分に絶縁油が吸収されて生じるとされており、非結晶の割合が大きいほど膨潤が大きいとされている。上述の各パラメータを変化させたときの膨潤指標をそれぞれ予め測定し、この蓄積したデータを参照して、製造に用いる複合紙の仕様や絶縁油の材質、及び(選択される)絶縁油の含浸温度に応じて膨潤指標の値を決定するとよい。   The value (absolute value) of the swelling index of the composite papers 30Ai and 30Ao can be set as appropriate. The swelling index varies depending on the specifications of the resin constituting the composite paper (resin crystallinity, etc.), the material of the insulating oil, the impregnation temperature, and the like. Swelling is said to be caused by absorption of insulating oil in the non-crystalline portion of the resin, and the swelling is said to increase as the proportion of non-crystalline increases. Measure the swelling index when changing each of the above parameters in advance, refer to this accumulated data, the specifications of the composite paper used for manufacturing, the material of the insulating oil, and the impregnation of the (selected) insulating oil The value of the swelling index may be determined according to the temperature.

膨潤指標の値(絶対値)が大き過ぎると、複合紙が過度に膨潤して含浸の不良や含浸時間の増大による生産性の低下を招く。また、曲げなどの機械的特性を損ねる恐れもある。膨潤指標の値(絶対値)が低過ぎると、導体側近傍の絶縁油の粘度を所定の値にするために、含浸する絶縁油(フレッシュな油)の粘度を高くする必要が生じる。この場合、含浸期間の増大による生産性の低下を招く恐れがある。従って、実際のケーブルの製造に基づき、複合紙30Ai,30Aoの膨潤指標の値(絶対値)はいずれも、機械的特性を損ねない範囲で上限値・下限値を設定することが好ましい。また、含浸する絶縁油(フレッシュな油)の種類や含浸温度における絶縁油の粘度によって許容される膨潤指標の範囲も変わる。ここで、複合紙の膨潤特性(膨潤指標)は、絶縁油の含浸の際に問題の無い範囲において膨潤が有効であることを示したものといえる。そのため、導体側の複合紙30Aiの膨潤指標を外周側の複合紙30Aoよりも相対的に大きくすることは、絶縁油の含浸への影響は小さい。従って、外周側の複合紙30Aoの膨潤指標を敢えて小さくする必要はなく、導体側の複合紙30Aiの膨潤指標を相対的に大きくすればよい。   If the value of the swelling index (absolute value) is too large, the composite paper will swell excessively, leading to poor impregnation and decreased productivity due to an increase in impregnation time. In addition, mechanical properties such as bending may be impaired. If the value of the swelling index (absolute value) is too low, it is necessary to increase the viscosity of the insulating oil (fresh oil) to be impregnated in order to set the viscosity of the insulating oil in the vicinity of the conductor side to a predetermined value. In this case, there is a possibility of causing a decrease in productivity due to an increase in the impregnation period. Therefore, it is preferable to set the upper and lower limits of the swelling index values (absolute values) of the composite papers 30Ai and 30Ao within a range that does not impair the mechanical characteristics, based on actual cable manufacture. In addition, the allowable range of swelling index varies depending on the type of insulating oil to be impregnated (fresh oil) and the viscosity of the insulating oil at the impregnation temperature. Here, it can be said that the swelling property (swelling index) of the composite paper indicates that the swelling is effective within a range where there is no problem when impregnated with the insulating oil. Therefore, making the swelling index of the composite paper 30Ai on the conductor side relatively larger than that of the composite paper 30Ao on the outer peripheral side has a small influence on the impregnation with the insulating oil. Therefore, it is not necessary to deliberately reduce the swelling index of the composite paper 30Ao on the outer peripheral side, and it is sufficient to relatively increase the swelling index of the composite paper 30Ai on the conductor side.

例えば、複合紙の膨潤指標をT-2015やポリブデン系絶縁油で評価すると、120℃での含浸で、T-2015を用いた場合の膨潤指標が7%程度、ポリブデン系絶縁油を用いた場合の膨潤指標が5%程度が挙げられる。複合紙が同じ場合でも、含浸する絶縁油の種類によって膨潤指標に差が生じ得る。そのため、上述の膨潤指標の測定値の前後、望ましくは測定値以下で膨潤指標を管理することが適当である。そして、絶縁油の含浸温度を決定して、外側複合紙及び導体側複合紙のそれぞれについて、実際のケーブルにおける膨潤指標の範囲を設定すると共に、使用する複合紙の管理を目的とした膨潤指標の測定条件(使用絶縁油、含浸温度)を定め、この条件での膨潤指標の管理範囲を定めることが好ましい。   For example, when the swelling index of composite paper is evaluated with T-2015 or polybutene insulating oil, when impregnation at 120 ° C, the swelling index when T-2015 is used is about 7%, and when polybudene insulating oil is used The swelling index is about 5%. Even when the composite paper is the same, the swelling index may vary depending on the type of insulating oil to be impregnated. Therefore, it is appropriate to manage the swelling index before and after the measured value of the swelling index described above, desirably below the measured value. Then, the impregnation temperature of the insulating oil is determined, and for each of the outer composite paper and the conductor side composite paper, the range of the swelling index in the actual cable is set, and the swelling index for the purpose of managing the composite paper to be used is set. It is preferable to determine the measurement conditions (the insulating oil used, the impregnation temperature) and the management range of the swelling index under these conditions.

そして、導体側領域13iを構築する複合紙30Aiの膨潤指標は、外周側領域13oを構築する複合紙30Aoの膨潤指標よりも大きいものとする。導体側領域13iとは、複合紙層の厚さの1/2よりも内周(導体)寄りとし、複合紙層の最内層から、複合紙層の厚さの1/4〜1/2ぐらいまでの範囲が挙げられる。   The swelling index of the composite paper 30Ai that constructs the conductor side region 13i is larger than the swelling index of the composite paper 30Ao that constructs the outer peripheral side region 13o. The conductor side region 13i is closer to the inner circumference (conductor) than 1/2 the thickness of the composite paper layer, and from the innermost layer of the composite paper layer to about 1/4 to 1/2 of the thickness of the composite paper layer The range is up to.

複合紙層の外周側から導体11側に向かって、連続的に又は段階的に膨潤指標が異なる複合紙を用いた構成とすることができる。具体的には、導体11側を構成する複合紙ほど、膨潤指標が大きいものを用いる。この場合、絶縁油の増粘を緻密に行える(油浸絶縁層13Aの径方向における絶縁油の増粘状態を細かく調整できる)と期待できる。また、この場合、外周側の複合紙の膨潤指標と、導体11側の複合紙の膨潤指標との差を大きく取り易い。一方、本実施形態のように膨潤指標が大きい複合紙30Aiからなる領域と、膨潤指標が小さい複合紙30Aoからなる領域との二層構造とすると、製造性に優れて好ましい。   A configuration in which composite papers having different swelling indices continuously or stepwise from the outer peripheral side of the composite paper layer toward the conductor 11 side can be used. Specifically, the composite paper constituting the conductor 11 side has a larger swelling index. In this case, it can be expected that the thickening of the insulating oil can be performed precisely (the thickened state of the insulating oil in the radial direction of the oil-immersed insulating layer 13A can be finely adjusted). In this case, the difference between the swelling index of the composite paper on the outer peripheral side and the swelling index of the composite paper on the conductor 11 side can be easily increased. On the other hand, a two-layer structure of a region made of the composite paper 30Ai having a large swelling index and a region made of the composite paper 30Ao having a small swelling index as in the present embodiment is preferable because of excellent manufacturability.

複合紙層において導体側に配置される複合紙30Aiの膨潤指標と、外周側に配置される複合紙30Aoの膨潤指標との差は、適宜選択することができ、例えば、0.2%以上、更に0.3%以上、特に0.5%以上が挙げられる。ここで、長距離海底電力線路に利用するような複合紙ソリッドケーブルを製造する場合、複合紙が大量に必要であり、長期間に亘って製造された大量の製造ロット品を使用して長期間に亘ってケーブルを製造する必要がある。そこで、例えば、製造ロットごとに膨潤指標を測定して、導体11側の複合紙30Ai、外周側の複合紙30Aoのそれぞれが規定の膨潤指標の範囲にあるように管理することで、信頼性のより高い複合紙ソリッドケーブルを長期間に亘り良好に製造できる。   The difference between the swelling index of the composite paper 30Ai disposed on the conductor side in the composite paper layer and the swelling index of the composite paper 30Ao disposed on the outer peripheral side can be selected as appropriate, for example, 0.2% or more, and further 0.3 % Or more, particularly 0.5% or more. Here, when manufacturing a composite paper solid cable used for a long-distance submarine power line, a large amount of composite paper is required, and a large number of production lots manufactured over a long period of time are used for a long time. It is necessary to manufacture a cable over the range. Therefore, for example, by measuring the swelling index for each production lot and managing each of the composite paper 30Ai on the conductor 11 side and the composite paper 30Ao on the outer peripheral side within the specified swelling index range, reliability can be improved. Higher composite paper solid cable can be manufactured well over a long period of time.

(効果)
導体11側の複合紙30Aiの膨潤指標が外周側の複合紙30Aoよりも大きいため、複合紙30Aiは、外周側の複合紙30Aoに吸収されなかった成分のうち低分子量側の成分を吸収することができる。すなわち、導体11側の複合紙30Aiには、膨潤指標が相対的に小さい複合紙30Aoの樹脂300oに吸収されない成分を含有する絶縁油が主として含浸される。そのため、複合紙ソリッドケーブル1Aは、導体11近傍で、絶縁油中の低分子量物質の吸収による絶縁油の増粘をより効果的に得ることができる。従って、複合紙ソリッドケーブル1Aは、運転時に高温になっても、導体11近傍に存在する絶縁油の粘度を増粘前の絶縁油(フレッシュな油)が高温となったときの粘度よりも高い状態とすることができ、絶縁油の移動を抑制できる。その結果、複合紙ソリッドケーブル1Aは、常時、絶縁油を導体11近傍に留められる。また、膨潤指標が相対的に大きい複合紙30Aiが導体11近傍で膨潤して複合紙30Ai間が密着できることからも、複合紙ソリッドケーブル1Aは、絶縁油の移動をより抑制できる。これらのことから、複合紙ソリッドケーブル1Aは、運転時、より高温になっても絶縁油の移動を抑制でき、絶縁油の移動に伴う導体近傍における絶縁性能の低下を抑制できることから、安定した絶縁性能を維持できる。
(effect)
Since the swelling index of the composite paper 30Ai on the conductor 11 side is larger than that of the composite paper 30Ao on the outer peripheral side, the composite paper 30Ai absorbs the component on the low molecular weight side among the components not absorbed by the composite paper 30Ao on the outer peripheral side. Can do. That is, the composite paper 30Ai on the conductor 11 side is mainly impregnated with an insulating oil containing a component that is not absorbed by the resin 300o of the composite paper 30Ao having a relatively small swelling index. Therefore, the composite paper solid cable 1A can more effectively obtain the thickening of the insulating oil due to the absorption of the low molecular weight substance in the insulating oil in the vicinity of the conductor 11. Therefore, even if the composite paper solid cable 1A becomes high temperature during operation, the viscosity of the insulating oil existing in the vicinity of the conductor 11 is higher than the viscosity when the insulating oil before being thickened (fresh oil) becomes high temperature. It can be in a state, and the movement of the insulating oil can be suppressed. As a result, the composite paper solid cable 1A can always keep the insulating oil near the conductor 11. Further, since the composite paper 30Ai having a relatively large swelling index swells in the vicinity of the conductor 11 and the composite paper 30Ai can be in close contact with each other, the composite paper solid cable 1A can further suppress the movement of the insulating oil. From these facts, the composite paper solid cable 1A can suppress the movement of the insulating oil even at higher temperatures during operation, and can suppress the deterioration of the insulating performance in the vicinity of the conductor due to the movement of the insulating oil. Performance can be maintained.

その他、複合紙ソリッドケーブル1Aは、複合紙への絶縁油の含浸過程での油増粘を考慮して、含浸する絶縁油(フレッシュな油)の粘度を低くすることができる。この場合でも導体11近傍の絶縁油の粘度を、絶縁油の移動に起因する欠陥の形成を抑制することが可能な粘度にすることができる。また、含浸する絶縁油の粘度を低く場合、(1)絶縁油を含浸させ易い、(2)絶縁油の含浸温度を低下することで、冷却時間の短縮を図ることができる、といった効果も奏する。この場合、複合紙ソリッドケーブル1Aは、生産性の向上を図ることができる。   In addition, the composite paper solid cable 1A can reduce the viscosity of the impregnated insulating oil (fresh oil) in consideration of the oil thickening in the process of impregnating the composite paper with the insulating oil. Even in this case, the viscosity of the insulating oil in the vicinity of the conductor 11 can be set to a viscosity that can suppress the formation of defects due to the movement of the insulating oil. In addition, when the viscosity of the insulating oil to be impregnated is low, (1) it is easy to impregnate the insulating oil, and (2) the cooling time can be shortened by lowering the impregnation temperature of the insulating oil. . In this case, the composite paper solid cable 1A can improve productivity.

また、外周側の複合紙30Aoの膨潤指標をより低くした場合には、導体11側の複合紙30Aiの膨潤及び絶縁油の増粘効果が大きい複合紙ソリッドケーブルとすることができる。加えて、この場合、絶縁油の含浸時、絶縁油は、金属シース15側で増粘が抑制され、複合紙層の外周側から内周側に向かっての含浸が容易となる。従って、この複合紙ソリッドケーブル1Aは、絶縁油を含浸させ易く、絶縁油の含浸時間を短縮できて、生産性に優れる。更に、この複合紙ソリッドケーブル1Aは、外周側領域13oの膨潤量が少ないことで、導体側領域13iを構成する複合紙30iが膨潤可能な尤度を十分に確保できる。   In addition, when the swelling index of the composite paper 30Ao on the outer peripheral side is made lower, a composite paper solid cable can be obtained in which the swelling of the composite paper 30Ai on the conductor 11 side and the thickening effect of the insulating oil are large. In addition, in this case, when the insulating oil is impregnated, the thickening of the insulating oil is suppressed on the metal sheath 15 side, and the impregnation from the outer peripheral side to the inner peripheral side of the composite paper layer becomes easy. Therefore, this composite paper solid cable 1A can be easily impregnated with insulating oil, can reduce the impregnation time of insulating oil, and is excellent in productivity. Further, the composite paper solid cable 1A can sufficiently secure the likelihood that the composite paper 30i constituting the conductor side region 13i can swell because the swelling amount of the outer peripheral side region 13o is small.

[実施形態2]
次に、図2を参照して、実施形態2の複合紙ソリッドケーブル1Bを説明する。実施形態2の複合紙ソリッドケーブル1Bの基本的構成は、実施形態1と同様であり、導体11の外周に油浸絶縁層13Bを具える。油浸絶縁層13Bは、複合紙を巻回してなる絶縁紙層(複合紙層)130Bに絶縁油が含浸されてなる。また、複合紙層の導体側領域13iを構成する複合紙30Biの膨潤指標は、外周側領域13oを構成する複合紙30Boの膨潤指標より大きい。そして、実施形態2における実施形態1との相違点は、複合紙30Bi,30Boに占める樹脂320i,320oの割合が異なる点にある。具体的には、導体11側の複合紙30Biに占める樹脂320iの割合が、外周側の複合紙30Boに占める樹脂320oの割合よりも大きい。以下、この相違点及びその効果を中心に説明し、その他の構成及び効果は、実施形態1と共通するため、説明を省略する。樹脂320i,320oの占める割合は、複合紙30Bi,30Boの樹脂比率(k値)に相当する。
[Embodiment 2]
Next, the composite paper solid cable 1B of Embodiment 2 will be described with reference to FIG. The basic configuration of the composite paper solid cable 1B of the second embodiment is the same as that of the first embodiment, and includes an oil immersion insulating layer 13B on the outer periphery of the conductor 11. The oil-immersed insulating layer 13B is formed by impregnating an insulating paper layer (composite paper layer) 130B formed by winding composite paper with insulating oil. Further, the swelling index of the composite paper 30Bi constituting the conductor side region 13i of the composite paper layer is larger than the swelling index of the composite paper 30Bo constituting the outer peripheral side region 13o. The difference between the second embodiment and the first embodiment is that the proportions of the resins 320i and 320o in the composite paper 30Bi and 30Bo are different. Specifically, the proportion of the resin 320i in the composite paper 30Bi on the conductor 11 side is larger than the proportion of the resin 320o in the composite paper 30Bo on the outer peripheral side. Hereinafter, this difference and its effects will be mainly described, and other configurations and effects are the same as those of the first embodiment, and thus description thereof will be omitted. The ratio of the resin 320i, 320o corresponds to the resin ratio (k value) of the composite paper 30Bi, 30Bo.

各複合紙30Bi,30Boのk値は、例えば、上述の範囲:0.4〜0.8から選択することができる。複合紙30Bi,30Boの厚さが等しい場合、樹脂320i,320oの占める割合に応じて、クラフト紙331i,332i,331o,332oの厚さを選択するとよい。   The k value of each composite paper 30Bi, 30Bo can be selected from, for example, the above range: 0.4 to 0.8. When the thicknesses of the composite papers 30Bi and 30Bo are equal, the thicknesses of the kraft papers 331i, 332i, 331o, and 332o may be selected according to the proportion of the resin 320i and 320o.

複合紙層の最内側から最外側に向かって、連続的に又は段階的に樹脂の占める割合が異なる複合紙を用いた形態とすることができる。複合紙30Bi,30Boの厚さが等しく、k値が異なる複合紙とすることで、上記形態を容易に構成することができる。図2に示すように、樹脂320iの占める割合が大きい複合紙30Biからなる領域(ここでは導体側領域13i)と、樹脂320oの占める割合が小さい複合紙30Boからなる領域(ここでは外周側領域13o)との二層構造とすると、製造性に優れて好ましい。   It can be set as the form using the composite paper from which the ratio for which resin occupies differs continuously or in steps from the innermost side to the outermost side of the composite paper layer. By using composite papers 30Bi and 30Bo having the same thickness and different k values, the above configuration can be easily configured. As shown in FIG. 2, a region composed of the composite paper 30Bi in which the proportion of the resin 320i is large (here, the conductor side region 13i) and a region composed of the composite paper 30Bo in which the proportion of the resin 320o is small (here, the outer peripheral side region 13o). ) And a two-layer structure are preferable because of excellent manufacturability.

(効果)
複合紙ソリッドケーブル1Bは、実施形態1の複合紙ソリッドケーブル1Aと同様に導体11の近傍の絶縁油の移動を抑制でき、長期に亘り安定した絶縁性能を有したり、生産性に優れたりする。特に、この例に示す複合紙ソリッドケーブル1Bでは、導体側の複合紙30Biの膨潤指標及び樹脂が占める割合(比率)の双方が外周側(金属シース15側)の複合紙30Boの膨潤指標及び樹脂が占める割合(比率)よりも大きい。そのため、ソリッドケーブル1Bは、導体11側の複合紙30Biが導体11側に到達した絶縁油中の低分子量成分を吸収することによる膨潤及び絶縁油の増粘をより大きくできることから、導体11の近傍で絶縁油をより増粘させ易く、かつ複合紙30Bi同士を密着させ易い。
(effect)
As with the composite paper solid cable 1A of Embodiment 1, the composite paper solid cable 1B can suppress the movement of the insulating oil in the vicinity of the conductor 11, has a stable insulation performance over a long period of time, and is excellent in productivity. . In particular, in the composite paper solid cable 1B shown in this example, both the swelling index of the composite paper 30Bi on the conductor side and the ratio (ratio) occupied by the resin are both the swelling index and the resin of the composite paper 30Bo on the outer peripheral side (metal sheath 15 side). Is greater than the proportion of Therefore, the solid cable 1B can increase swelling and thickening of the insulating oil by absorbing the low molecular weight component in the insulating oil that the composite paper 30Bi on the conductor 11 side has reached the conductor 11 side. Therefore, it is easy to increase the viscosity of the insulating oil and to make the composite paper 30Bi adhere to each other.

本発明は、上述した実施の形態に限定されるものではなく、本発明の要旨を逸脱しない範囲で適宜変更することが可能である。例えば、複合紙の厚さ、絶縁油の材質などを適宜変更することができる。   The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention. For example, the thickness of the composite paper, the material of the insulating oil, and the like can be changed as appropriate.

本発明の複合紙ソリッドケーブルは、長距離・大容量の電力供給線路、特に海底電力線路の構成部材に好適に利用することができる。   The composite paper solid cable of the present invention can be suitably used as a constituent member of a long-distance and large-capacity power supply line, particularly a submarine power line.

1A,1B 複合紙ソリッドケーブル 130A,130B 絶縁紙層(複合紙層)
11 導体 12 内部半導電層 13A,13B 油浸絶縁層 13i 導体側領域
13o 外周側領域 14 外部半導電層 15 金属シース 16 防食層
30,30Ai,30Ao,30Bi,30Bo 複合紙 3a,300,300i,300o,320i,320o 樹脂
3b,310,311i,312i,311o,312o,331i,332i,331o,332o クラフト紙 g 隙間
1A, 1B Composite paper solid cable 130A, 130B Insulating paper layer (composite paper layer)
11 Conductor 12 Inner semiconductive layer 13A, 13B Oil immersion insulating layer 13i Conductor side area
13o Peripheral area 14 External semiconductive layer 15 Metal sheath 16 Anticorrosion layer
30,30Ai, 30Ao, 30Bi, 30Bo Composite paper 3a, 300,300i, 300o, 320i, 320o Resin
3b, 310,311i, 312i, 311o, 312o, 331i, 332i, 331o, 332o Kraft paper g Crevice

Claims (6)

樹脂とクラフト紙とが積層一体化された複合紙が導体の外周に巻回されてなる複合紙層に絶縁油が含浸された油浸絶縁層を具える複合紙ソリッドケーブルであって、
前記複合紙に絶縁油を含浸させる前後における前記樹脂の厚さの変化率を膨潤指標とするとき、
前記油浸絶縁層において導体側領域を構成する複合紙の膨潤指標が、前記油浸絶縁層において外周側領域を構成する複合紙の膨潤指標よりも大きい複合紙ソリッドケーブル。
A composite paper solid cable comprising an oil-immersed insulation layer in which a composite paper layer in which resin and kraft paper are laminated and integrated is wound around the conductor and impregnated with insulating oil.
When the rate of change of the thickness of the resin before and after impregnating the composite paper with an insulating oil is used as a swelling index,
A composite paper solid cable, wherein a swelling index of a composite paper constituting a conductor side region in the oil-immersion insulating layer is larger than a swelling index of a composite paper constituting an outer peripheral side region in the oil-immersion insulating layer.
前記導体側領域を構成する複合紙の前記膨潤指標、及びこの複合紙に占める樹脂の割合の双方が、前記外周側領域を構成する複合紙の前記膨潤指標、及びこの複合紙に占める樹脂の割合よりも大きい請求項1に記載の複合紙ソリッドケーブル。   Both the swelling index of the composite paper constituting the conductor side region and the ratio of the resin occupying the composite paper are the swelling index of the composite paper constituting the outer peripheral side region, and the ratio of the resin occupying the composite paper. The composite paper solid cable according to claim 1, wherein the composite paper is a larger cable. 前記油浸絶縁層の外周側から導体側に向かって、連続的に又は段階的に前記複合紙の膨潤指標が大きい請求項1又は2に記載の複合紙ソリッドケーブル。   3. The composite paper solid cable according to claim 1, wherein the swelling index of the composite paper is large continuously or stepwise from the outer peripheral side of the oil immersion insulating layer toward the conductor side. 前記複合紙は、ポリオレフィン系樹脂とクラフト紙とが積層一体化されている請求項1〜3のいずれか1項に記載の複合紙ソリッドケーブル。   4. The composite paper solid cable according to claim 1, wherein the composite paper includes a polyolefin resin and kraft paper laminated and integrated. 前記複合紙は、ポリプロピレン層の両面にクラフト紙が積層一体化されている請求項1〜4のいずれか1項に記載の複合紙ソリッドケーブル。   The composite paper solid cable according to any one of claims 1 to 4, wherein the composite paper has a kraft paper laminated and integrated on both sides of a polypropylene layer. 直流送電に用いられる請求項1〜5のいずれか1項に記載の複合紙ソリッドケーブル。   6. The composite paper solid cable according to claim 1, which is used for direct current power transmission.
JP2012160020A 2012-07-18 2012-07-18 Composite paper solid cable Active JP5796783B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2012160020A JP5796783B2 (en) 2012-07-18 2012-07-18 Composite paper solid cable

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2012160020A JP5796783B2 (en) 2012-07-18 2012-07-18 Composite paper solid cable

Publications (2)

Publication Number Publication Date
JP2014022201A JP2014022201A (en) 2014-02-03
JP5796783B2 true JP5796783B2 (en) 2015-10-21

Family

ID=50196855

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2012160020A Active JP5796783B2 (en) 2012-07-18 2012-07-18 Composite paper solid cable

Country Status (1)

Country Link
JP (1) JP5796783B2 (en)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5828111A (en) * 1981-08-13 1983-02-19 住友電気工業株式会社 Of cable
JP3024627B2 (en) * 1998-02-03 2000-03-21 住友電気工業株式会社 Submarine solid cable

Also Published As

Publication number Publication date
JP2014022201A (en) 2014-02-03

Similar Documents

Publication Publication Date Title
JP5369507B2 (en) Submarine solid cable manufacturing method and submarine solid cable
CN102712179B (en) High voltage direct current cable having an impregnated stratified insulation
US6201191B1 (en) Solid DC cable
JP5796783B2 (en) Composite paper solid cable
JP5883680B2 (en) Oil-filled transformer
JP5954610B2 (en) Composite paper solid submarine cable for DC
JP2010104122A (en) Intermediate connecting structure of solid cable
JP4192323B2 (en) Oil immersed solid power cable
WO1997004466A1 (en) Power cable, manufacturing method and impregnating compound
JP3803162B2 (en) DC high viscosity oil immersion power cable
JP5354159B2 (en) Solid cable manufacturing method
JP3614484B2 (en) High viscosity oil immersion insulated cable
JP2011216292A (en) Direct current oil immersed power cable
JP2013218798A (en) Solid cable and design/manufacture/management method therefor
JP6429010B2 (en) Solid cable manufacturing management method and test apparatus used for solid cable manufacturing management method
JP3050316B1 (en) Submarine solid cable
JP3819098B2 (en) Oil immersion power cable and its installation method
JP2010104177A (en) Intermediate joint structure of solid cable
Møllerhøj et al. Flat pressure cable
JP2009076439A (en) Power transmission line and its laying method
WO2017052119A1 (en) Conductor compression sleeve and ultra-high-voltage direct current power cable system using same
JP3973722B2 (en) DC oil immersion power cable
Sakurai et al. 275 kV Self-Contained Oil-Filled Cable Insulated with Polymethylpentene Laminated Paper
JP2018032500A (en) DC solid cable
JP2009026612A (en) Solid cable and its manufacturing method

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20150126

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: 20150724

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20150806

R150 Certificate of patent or registration of utility model

Ref document number: 5796783

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