JP2010103007A - Solid cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid cable, capable of suppressing movement of insulating oil associated with thermal history of an insulating layer in operation of the cable to stabilize the insulating characteristic by thickening the insulating oil in the insulating layer, and to provide a connection part thereof. <P>SOLUTION: The solid cable includes the insulating layer 30 impregnated with insulating oil, at least a part of the insulating layer 30 being constituted by winding a composite paper having an insulating paper and a plastic layer. The insulating paper is made through pulp production step and insulating paper making step, and in at least one of the pulp production step and the insulating paper making step, acid washing and neutralization treatment are performed. The neutralization treatment is performed by use of a neutralizer containing a metal ion. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solid cable and its connecting portion. In particular, the present invention relates to a solid cable that can suppress the movement of insulating oil impregnated in an insulating layer with a change in temperature during cable operation.

  Solid cables have been proposed as power lines such as submarine cables. A typical solid cable includes, in order from the center, a conductor, an inner semiconductive layer, an insulating layer, an outer semiconductive layer, a metal sheath, an anticorrosion layer, and an iron wire armor. As an insulating layer of this solid cable, there is one using a composite paper having an insulating paper and a plastic layer (Patent Document 1). More specifically, the composite paper is wound to form an insulating layer, and the inner layer of the metal sheath is impregnated with medium viscosity oil or high viscosity oil.

  The insulating paper (craft paper) constituting the composite paper is usually manufactured through a pulp manufacturing process and an insulating paper manufacturing process performed by different companies. In the pulp manufacturing process, wood chips as raw materials are digested and the obtained pulp is washed. In the insulating paper manufacturing process, first, the pulp obtained in the pulp manufacturing process is washed as necessary, and then disaggregated and beaten. Further, predetermined chemicals are added to the pulp solution in which the pulp is dispersed in an aqueous solution ( Paper). Subsequently, the obtained paper stock is introduced into a paper machine to make paper. Furthermore, if necessary, the paper is densified with the obtained paper calender and the paper surface is smoothed and wound on a roll. In such a papermaking process, the object to be treated is washed with water in the pulp manufacturing process and the insulating paper manufacturing process.

JP 2000-113734 A

  However, in recent years, it may be difficult to obtain raw materials with stable quality due to changes in the market conditions of raw materials for insulating paper. Under these circumstances, the performance and quality of pulp and insulating paper are being stabilized, but the viscosity of the insulating oil is excessively high in solid cables made with composite paper using some insulating paper. I found out that

  On the other hand, when the insulating layer is impregnated with medium / high viscosity oil, the insulating oil in the vicinity of the conductor expands with a low viscosity when the load of the cable is turned on, and moves in the outer circumferential direction of the insulating layer. However, this insulating oil shrinks and becomes highly viscous when the load is turned off, and cannot rapidly shift from the outer peripheral side to the inner peripheral side of the insulating layer, generating a negative pressure in the insulating layer near the conductor, and insulating the insulating layer. There is a risk of local depletion of oil.

  The present invention has been made in view of the above circumstances, and one of its purposes is to increase the viscosity of the insulating oil in the insulating layer, thereby allowing the insulating oil to move with the thermal history of the insulating layer during cable operation. An object of the present invention is to provide a solid cable and its connecting portion that can suppress and stabilize the insulation characteristics.

  The inventors of the present invention made composite paper with insulating papers of different quality and performance, made a prototype of a solid cable in which the insulating layer was composed of the composite paper, and examined the impregnation characteristics of the insulating oil into the insulating layer. As a result, it has been found that there are some in which the viscosity of the insulating oil is high and the insulating layer is not sufficiently impregnated with the insulating oil, and that the insulating oil is appropriately impregnated. More specifically, the insulating paper that is only washed with water in the washing process of the pulp manufacturing process and the insulating paper manufacturing process has no particular problem in the impregnation characteristics of the insulating oil, but is subjected to pickling and neutralization treatment and neutralization. It has been found that the insulating paper treated with a neutralizing agent containing metal ions has a large tendency to thicken the insulating oil and may impair the impregnation characteristics of the insulating oil. The present invention has been completed based on these findings, and achieves the above object by actively using insulating paper that thickens the insulating oil.

  The solid cable of the present invention relates to a solid cable comprising an insulating layer impregnated with insulating oil, and at least a part of the insulating layer is formed by winding a composite paper having an insulating paper and a plastic layer. In this solid cable, the insulating paper is manufactured through a pulp manufacturing process and an insulating paper manufacturing process, and at least one of the pulp manufacturing process and the insulating paper manufacturing process is pickled and neutralized. And this neutralization process was performed using the neutralizing agent containing a metal ion, It is characterized by the above-mentioned.

  According to this structure, the insulating paper which comprises composite paper uses the neutralizing agent containing a metal ion by the neutralization process of one or both of a pulp manufacturing process and an insulating paper manufacturing process. Therefore, if a composite paper is constituted using the obtained insulating paper and an insulating layer is formed with the composite paper, the viscosity of the insulating oil can be increased moderately when impregnated with the insulating oil. That is, it is possible to make it difficult for the insulating oil to move with respect to the temperature history of the insulating layer that occurs when the load is turned on and off during cable operation. As a result, the above-described local exhaustion of the insulating oil can be suppressed, and a solid cable having stable insulating characteristics can be obtained.

  In the solid cable of the present invention, the insulating paper may be an insulating paper that has been pickled and neutralized in a pulp manufacturing process.

  According to this configuration, since the neutralizing agent containing metal ions is used in the neutralization process in the pulp manufacturing process before the insulating paper manufacturing process, the same metal ions as the metal ions in the neutralizing agent are used as the insulating paper. It is thought that it will remain inside. At that time, elements such as Ca in the insulating paper are often reduced. Therefore, the presence of this residual substance can be used as an index of the pickled / neutralized insulating paper. Therefore, when such insulating paper is used for the insulating layer as composite paper, it can be considered that the ratio of the high molecular weight of the insulating oil in the insulating layer increases and the viscosity of the insulating oil can be increased.

  In the solid cable of the present invention, the insulating paper may be an insulating paper that has been pickled and neutralized in an insulating paper manufacturing process.

  According to this configuration, since the neutralizing agent containing metal ions is used in the neutralizing process in the insulating paper manufacturing process, it is considered that the same metal ions as the metal ions in the neutralizing agent remain as some substance in the insulating paper. It is done. At that time, elements such as Ca are often reduced. Therefore, the presence of this residual substance can be used as an index of the pickled / neutralized insulating paper. Therefore, it is considered that when insulating paper treated with such a neutralizing agent is used as an insulating layer as composite paper, it can contribute to viscosity adjustment of insulating oil.

  In the solid cable of the present invention, the insulating paper may be an insulating paper in which pickling and neutralization are performed in both the pulp manufacturing process and the insulating paper manufacturing process.

  According to this configuration, since the neutralizing agent containing metal ions is used in each neutralization treatment in both the pulp manufacturing process and the insulating paper manufacturing process, the same metal ions as the metal ions in the neutralizing agent are contained in the insulating paper. It remains as some substance. Therefore, when this insulating paper is used for the insulating layer as a composite paper, the viscosity of the insulating oil can be effectively increased.

  In the solid cable of the present invention, the insulating oil contains polybuden.

  Polybutene is an insulating oil having a double bond, and it is presumed that this double bond is bonded to other molecules to increase the proportion of the polymer material in the insulating oil. For this reason, when using an insulating oil having a double bond, such as polybutene, it is considered effective to use the insulating paper defined in the present invention to moderately thicken the insulating oil.

  In the solid cable of the present invention, it is preferable that the concentration of the same metal ion as that in the neutralizing agent in the insulating paper is more than 300 ppm.

  Usually, the same metal ion as the metal ion in the neutralizing agent is present in water or the like, and the insulating paper that is merely washed with water in the washing step contains a certain amount of substances derived from this metal ion. Since the upper limit of the content of the metal ions in the insulating paper that is only washed with water is about 300 ppm, if the concentration of the metal ions in the insulating paper exceeds 300 ppm, the insulating paper is not neutralized in the manufacturing process. It is considered that a neutralizing agent containing metal ions is used. The concentration of this metal ion can be measured by atomic absorption analysis or ion chromatography.

  In the solid cable of the present invention, the metal ion contained in the neutralizing agent may be at least one metal ion selected from Groups 2 and 13 of the periodic table.

  By this configuration, by obtaining an insulating paper using a neutralizing agent that does not contain at least one metal ion selected from Groups 2 and 13 of the Periodic Table, when the insulating layer is configured using the insulating paper, The thickening of the insulating oil can be effectively suppressed.

  A specific example of the metal ion contained in the neutralizing agent is Mg ion. In particular, when insulating paper is obtained using a neutralizing agent containing Mg ions as metal ions, and the insulating layer is formed using the insulating paper, the insulating oil can be effectively thickened. Other specific examples of metal ions contained in the neutralizing agent include Al ions.

  In the solid cable of the present invention, the thickness of the insulating layer is preferably 10 mm or more.

  In the case of a solid cable having a relatively thick insulating layer, once the insulating oil moves, the return tends to be more difficult. Since the insulating paper defined in the present invention can increase the viscosity of the insulating oil to an appropriate level, it is particularly effective to apply it to a solid cable having a thick insulating layer.

  In the solid cable of the present invention, it is preferable to use different insulating layers on the inner and outer peripheral sides of the insulating layer. Specifically, the insulating paper of the composite paper constituting the inner peripheral side in the insulating layer is an insulating paper in which the neutralization treatment is performed using a neutralizing agent containing metal ions. On the other hand, the insulating paper of the composite paper constituting the outer peripheral side of the insulating layer is an insulating paper in which the neutralization treatment is performed without using a neutralizing agent containing metal ions.

  According to this configuration, the insulating paper that does not thicken the insulating oil is used on the outer peripheral side of the insulating layer, and the insulating paper that has the function of thickening the insulating oil is used on the inner peripheral side. The insulating oil is impregnated from the outer peripheral side to the inner peripheral side of the insulating layer. Therefore, in the initial stage of impregnation with the insulating oil, the insulating oil can be smoothly impregnated if the insulating oil is not thickened on the outer peripheral side of the insulating layer. On the other hand, the inner peripheral side of the insulating layer is also in the vicinity of the conductor and is a place where the temperature becomes high when the load is turned on. For this reason, if insulating paper that thickens the insulating oil is used on the inner peripheral side of the insulating layer, the insulating oil on the inner peripheral side is thickened, and the insulating oil Movement can be suppressed. As a result, it is possible to suppress the generation of voids in the insulating layer in the vicinity of the conductor, which is likely to cause local exhaustion of the insulating oil.

  On the other hand, the connection part of the solid cable of the present invention includes a conductor connection part that connects the exposed conductors to the ends of the pair of cable cores in which the conductor and the oil-insulated insulating layer covering the conductors are exposed stepwise. And an insulating layer for connection constituted by winding an insulating tape around the ends of the cable cores and the outer periphery of the conductor connecting portion. Here, the insulating tape is a composite paper having an insulating paper and a plastic layer. And the said insulating paper is manufactured through a pulp manufacturing process and an insulating paper manufacturing process, At least one of this pulp manufacturing process and an insulating paper manufacturing process is pickled and neutralized, It was performed using a neutralizing agent containing metal ions.

  According to this configuration, as in the case of the solid cable of the present invention, if the composite paper is formed using the insulating paper containing the metal ions, and the connection insulating layer is formed with the composite paper, the connection insulating layer When the insulating oil is impregnated, the viscosity of the insulating oil can be increased moderately. That is, it is possible to make it difficult for the insulating oil to move with respect to the temperature history of the connecting insulating layer that occurs when the load is turned on and off during cable operation. As a result, local depletion of the insulating oil in the connection insulating layer can be suppressed, and a connection portion having stable insulating characteristics can be obtained.

  According to the solid cable of the present invention and the connection portion thereof, in the process of manufacturing the insulating paper constituting the composite paper, the neutralizing agent containing metal ions is used for the neutralization treatment to insulate the cable or the insulating layer for connection. When impregnated with oil, the viscosity of the insulating oil can be increased moderately. Thereby, the movement of the insulating oil in the cable or the insulating layer for connection can be effectively suppressed, and the local depletion of the insulating oil can be effectively suppressed from occurring in the insulating layer.

[Solid cable]
As shown in FIG. 1, the solid cable 100 of the present invention includes a conductor 10, an inner semiconductive layer 20, an insulating layer 30, an outer semiconductive layer 40, a metal sheath 50, an anticorrosion layer 60, and an iron wire armor 70 in order from the center. Prepare. Among these, the inner layer of the metal sheath 50 is impregnated with insulating oil. If necessary, a reinforcing layer 80 may be provided on the metal sheath 50 or the anticorrosion layer 60. The most characteristic feature of the present invention is that at least a part of the insulating layer 30 is composed of a composite paper having an insulating paper and a plastic layer, and the composite paper is a specific composite paper. In the following description, the configuration of the insulating layer 30 will be mainly described.

<Configuration other than insulating layer>
As the conductor 10, a so-called keystone conductor obtained by twisting a plurality of copper strands can be used. The inner semiconductive layer 20 and the outer semiconductive layer 40 are configured by winding a carbon tape or the like. The metal sheath 50 is made of lead. The anticorrosion layer 60 is formed of a resin such as polyethylene (PE). The reinforcing layer 80 is a layer that shares the hoop stress applied to the metal sheath 50, and is configured by winding a belt-shaped material made of a high tensile strength material such as stainless steel.

《Insulating layer》
The insulating layer 30 is configured by spirally winding a composite tape (composite paper) in which insulating paper is laminated on one or both sides of a plastic layer. For example, polypropylene (PP) is used for the plastic layer of the composite tape, and kraft paper is used for the insulating paper. More specifically, PPLP (registered trademark of Sumitomo Electric Industries, Ltd.) obtained by extruding PP between a pair of kraft papers can be used as the composite tape. As this composite tape, for example, a suitable one in which the ratio (k value) of the thickness of the PP layer to the total thickness of the composite tape is 40 to 90% can be used.

  This insulating paper (craft paper) is manufactured through a pulp manufacturing process and an insulating paper manufacturing process. In the pulp manufacturing process, wood chips as raw materials are digested and the obtained pulp is washed. In the insulating paper manufacturing process, first, the pulp obtained in the pulp manufacturing process is washed as necessary, and then disaggregated and beaten. Further, predetermined chemicals are added to the pulp solution in which the pulp is dispersed in an aqueous solution ( Paper). Subsequently, the obtained paper stock is introduced into a paper machine to make paper. The insulating paper manufacturing process after introducing the stock into the paper machine usually includes a wire part, a press part, and a dryer part. In the wire part, the paper stock is spread evenly on the papermaking net and taken out as wet paper. In the press part, the wet paper is compressed and squeezed. In the dryer part, the wet paper after squeezing is dried.

  In one or both of the above-described pulp production process and insulating paper production process, the treatment target is pickled and neutralized. When this pickling and neutralization are performed, the neutralization is performed using a neutralizing agent containing metal ions. An example of a neutralizing agent containing metal ions is a neutralizing agent containing Mg ions. Hereinafter, the insulating paper obtained through neutralization using the neutralizing agent containing metal ions is referred to as thickened insulating paper. Moreover, the insulating paper which performed the said neutralization process without using the neutralizing agent containing a metal ion is called non-thickening type insulating paper.

  The insulating layer 30 may be configured using a composite tape at least in part. For example, (1) the insulating layer 30 is composed of a composite tape alone, (2) the insulating layer 30 is composed of a combination of a paper tape and a composite tape, or (3) the insulating layer is composed of a combination of a resin tape and a composite tape. Or 30. The method of combining various insulating tapes includes forming different types of insulating tape winding layers on a part of the insulating layer 30 in the thickness direction, or alternately winding different types of insulating tapes. Of course, the paper tape may also be made of thickened insulating paper.

  The composite tape constituting the insulating layer 30 may be all made of thickened insulating paper as long as it does not hinder impregnation with insulating oil. However, it is preferable to use thickened insulating paper for only a part of the insulating layer 30. Impregnation of the insulating layer 30 with the insulating oil is performed by heating the insulating oil to a predetermined temperature, pressurizing it to a predetermined pressure, and infiltrating the insulating oil from the outer peripheral side of the insulating layer 30 toward the inner peripheral side. At this time, the viscosity of the thickened insulating paper tends to increase the viscosity of the insulating oil, whereas the non-thickened insulating paper tends to be thicker or thinner than the insulating oil. Therefore, if a composite tape using non-thickening type insulating paper is arranged in the outer peripheral region of the insulating layer 30, the thickening of the insulating oil in the outer peripheral region is suppressed in the initial impregnation of the insulating oil, and the insulating layer 30 Smooth insulation oil impregnation up to the inner peripheral side is possible. On the other hand, the inner peripheral area of the insulating layer 30 in the vicinity of the conductor is composed of a composite tape using thickened insulating paper to increase the viscosity of the insulating oil in the inner peripheral area, thereby generating heat in the conductor during cable operation. In contrast, the movement of the insulating oil is suppressed. For example, the insulating layer 30 is composed of composite paper using thickened insulating paper for the inner peripheral side, for example, about half the thickness of the insulating layer 30, and the remainder is made of non-thickened insulating paper. For example, it may be composed of composite paper. The remaining portion may be composed of composite paper using insulating paper that has been washed with water without performing pickling and neutralization. In addition, since the insulating oil easily moves between the outer semiconductive layer 40 and the metal sheath 50, a thickened insulating paper may be arranged on the surface layer portion of the outer peripheral region of the insulating layer 30. According to this configuration, it is expected to suppress the movement of the insulating oil between the outer semiconductive layer 40 and the metal sheath 50 by thickening the insulating oil at the surface layer portion of the outer peripheral region of the insulating layer 30. The Further, if the region where the thickened insulating paper is disposed is the surface layer portion of the insulating layer, the thickened insulating paper is unlikely to become an obstacle when the insulating layer is impregnated with the insulating oil.

《Insulating oil》
As cable insulation oil impregnated into the insulating layer 30, the kinematic viscosity at 60 ° C is 500mm ² / s (500cst) or more, especially 1000
High viscosity oil of cst or higher, or medium viscosity oil having a kinematic viscosity at 60 ° C. of 10 mm ² / s (10 cst) or more and less than 500 mm ² / s (500 cst) can be used. In particular, insulating oil containing a double bond can be suitably used. Insulating oil containing double bonds tend to thicken the insulating oil when thickened insulating paper is used for the insulating layer 30. Therefore, the thickened insulating paper is effective for thickening the insulating oil in combination with the insulating oil having a double bond.

<Cable types>
The solid cable of the present invention can be used for both DC cables and AC cables. In particular, it is suitable to use as a DC cable that does not require consideration of dielectric loss. In the pulp manufacturing process and the insulating paper manufacturing process, when pickling and neutralization are not performed, impurities may not be sufficiently removed from the processing target. Such an insulating paper has a poor dielectric loss tangent (tan δ) characteristic, and may not be preferable for an AC cable in which the dielectric characteristic is regarded as important. On the other hand, in a DC cable, basically, it is sufficient that the resistivity of the insulating layer 30 can be managed. Therefore, a DC cable can be configured without any particular trouble even if an insulating paper in which the washing in the pulp manufacturing process and the insulating paper manufacturing process is only water washing is used as part of the insulating layer.

[Solid cable connections]
Next, the intermediate connection part of the solid cable of the present invention will be described with reference to FIG. The solid cable to be connected has the same structure as the cable 100 shown in FIG. The pair of solid cables 100 to be connected have the above-described constituent members stripped at the ends thereof. The intermediate connection portion 200 that connects the two cables 100 connects the conductors 10 and the end portions of the pair of cable cores 100c where the insulating layer 30 covering the conductors 10 is exposed stepwise and the exposed conductors 10 to each other. A conductor connecting portion 10J and a connecting insulating layer 30J configured on the end of the cable core 100c and the outer periphery of the conductor connecting portion 10J are provided. The connecting insulating layer 30J is also impregnated with insulating oil. In FIG. 2, the inner and outer semiconductive layers are omitted.

  The conductor connection portion 10J is configured by welding the conductors 10 exposed from the end of the cable core 100c of each cable 1 or connecting the conductors 10 using a connection sleeve.

  On the outer periphery of the conductor connection portion 10J and the exposed conductor 10, in the same manner as the cable 1, in order from the inside, a connection insulating layer 30J composed of composite paper, a metal sheath 50J formed of lead, and formed of polyethylene The anticorrosion layer 60J, the reinforcing layer 80J composed of a stainless steel strip, and the iron wire armor 70J composed of an iron wire or the like are formed.

The insulating layer 30J for connection is a tape-like composite paper similar to the insulating layer 30 of the cable.
(PPLP (registered trademark)) is spirally wound with a gap and part of the composite paper constituting the insulating layer 30 of the cable is rewound. The composite paper added to form the connection insulating layer 30J is impregnated with the same insulating oil as the cable insulating oil before winding. Further, the same insulating oil as that of the cable exists between the composite papers. The insulating oil existing between the composite papers is used as a spilling oil when assembling the intermediate connection portion 200.

  A thickened insulating paper is used as the insulating paper of the composite paper constituting the connecting insulating layer 30J. By using thickened insulating paper for the connecting insulating layer 30J, the insulating oil in the connecting insulating layer 30J is thickened, and the insulation in the connecting insulating layer 30J is insulated against the heat generated by the conductor 10 during cable operation. The movement of oil can be suppressed. Further, in this intermediate connection portion, the thickened insulating paper may be disposed on the surface layer portion of the insulating layer 30J, as in the case of the cable.

  A plurality of types of test cables having the same configuration as the solid cable shown in FIG. 1 and having different cleaning conditions in the manufacturing process of the insulating paper used for the composite paper are manufactured, and the cable is impregnated with insulating oil. The impregnation conditions for the insulating oil are common to each test cable. Then, the impregnated test cable was disassembled, and the viscosity change of the insulating oil in the insulating layer was examined. The specifications of the test cable are as follows.

(Insulating layer)
Constituent material: PPLP (k value is about 70% by super calendar processing)
PPLP insulating paper: Kraft paper obtained by washing as shown in Table 1 in the pulp manufacturing process and the insulating paper manufacturing process.
PPLP thickness: 100μm
Insulation layer thickness: 16mm
(Insulating oil)
Medium viscosity polybutene oil (HV-15, Nippon Petrochemical Co., Ltd.)
Kinematic viscosity at 40 ° C: about 650mm ² / s
Kinematic viscosity at 60 ° C: approx. 200 mm ² / s

  Table 1 shows the cleaning conditions and the impregnation characteristics of the test cable performed in the process of manufacturing the insulating paper constituting the PPLP. In Table 1, “water” indicates that after washing with water only, and “acid + neutralization (Mg)” indicates that after acid washing and neutralization with a neutralizing agent containing Mg ions. The impregnation characteristics are “no” when the test cable is disassembled and the thickening of the insulating oil is recognized, and “no” when no thickening is recognized.

  First, sample No. 10 was not washed or neutralized, but only washed with water, so the substance derived from Mg ions was not excessively contained in the insulating paper, and thickening was observed in the insulating oil. There wasn't. The Mg ion concentration contained in the insulating paper of Sample No. 10 was 300 ppm or less. However, the dielectric loss tangent of the insulating paper was large and the dielectric properties were inferior, probably because the processing object was not sufficiently cleaned in the pulp manufacturing process and the insulating paper manufacturing process.

  In contrast, Sample No. 20 is pickled and neutralized in both the pulp manufacturing process and the insulating paper manufacturing process, and each neutralization process uses a neutralizing agent containing Mg ions. Is going. Therefore, thickening was recognized in insulating oil. Note that the Mg ion concentration contained in the insulating paper of Sample No. 20 was more than 300 ppm.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the insulating layer is divided into three regions in the thickness direction, the inner peripheral region is composed of composite tape using thickened insulating paper, and the intermediate region is composed of composite tape using thickened insulating paper and non-thickened type For example, a composite tape using insulating paper is alternately wound and the outer peripheral region is formed of a composite tape using non-thickened insulating paper.

  The solid cable and its connecting portion of the present invention can be suitably used for a submarine cable, particularly a DC submarine cable.

It is a cross-sectional view of a solid cable according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the connection part of the solid cable which concerns on embodiment of this invention.

Explanation of symbols

100 solid cable
10 Conductor 20 Internal semiconductive layer 30 Insulating layer 40 External semiconductive layer
50 Metal sheath 60 Anticorrosion layer 70 Iron wire armor 80 Reinforcement layer
200 Intermediate connection
100c cable core
10J Conductor connection 30J Insulation layer for connection 50J Metal sheath 60J Anticorrosion layer
70J Iron wire armor 80J Reinforcement layer

Claims (11)

A solid cable comprising an insulating layer impregnated with insulating oil, at least part of the insulating layer being formed by winding a composite paper having an insulating paper and a plastic layer;
The insulating paper is manufactured through a pulp manufacturing process and an insulating paper manufacturing process,
At least one of this pulp manufacturing process and insulating paper manufacturing process, pickling and neutralization are performed,
A solid cable characterized in that this neutralization treatment was performed using a neutralizing agent containing metal ions. The solid cable according to claim 1, wherein the insulating paper is an insulating paper that has been pickled and neutralized in a pulp manufacturing process. The solid cable according to claim 1, wherein the insulating paper is an insulating paper that has been pickled and neutralized in an insulating paper manufacturing process. The solid cable according to claim 1, wherein the insulating paper is an insulating paper in which pickling and neutralization are performed in both a pulp manufacturing process and an insulating paper manufacturing process. The solid cable according to any one of claims 1 to 4, wherein the insulating oil contains polybutene. The solid cable according to any one of claims 1 to 5, wherein a concentration of the same metal ion as that in the neutralizing agent in the insulating paper is more than 300 ppm. 7. The solid cable according to claim 1, wherein the metal ion contained in the neutralizing agent is at least one metal ion selected from Groups 2 and 13 of the periodic table. The solid cable according to claim 1, wherein the metal ions contained in the neutralizing agent are Mg ions. The solid cable according to claim 1, wherein the insulating layer has a thickness of 10 mm or more. The insulating paper of the composite paper constituting the inner peripheral side in the insulating layer is an insulating paper in which the neutralization treatment is performed using a neutralizing agent containing metal ions,
The insulating paper of the composite paper constituting the outer peripheral side in the insulating layer is an insulating paper in which the neutralization treatment is performed without using a neutralizing agent containing metal ions. The solid cable according to any one of the above items. The ends of the pair of cable cores in which the conductor and the oil-insulated insulating layer covering the conductors are exposed stepwise, the conductor connecting portions that connect the exposed conductors, and the ends of the cable cores and the conductor connecting portions A connection portion of a solid cable comprising an insulating layer for connection constituted by winding an insulating tape around the outer periphery of
The insulating tape is a composite paper having an insulating paper and a plastic layer,
The insulating paper is manufactured through a pulp manufacturing process and an insulating paper manufacturing process,
At least one of this pulp manufacturing process and insulating paper manufacturing process, pickling and neutralization are performed,
The solid cable connecting portion is characterized in that the neutralization treatment is performed using a neutralizing agent containing metal ions.

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