Cable and cable system

Abstract

To enhance durability.SOLUTION: A cable 2 comprises at least one power line and a covering body that surrounds the at least one power line, wherein a first range Ar in a longitudinal direction of the at least one power line and the covering body has higher bending rigidity than other ranges.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to cables and cable systems. [Background technology]

[0002] In recent years, the development of offshore wind power generation has progressed. Such offshore wind power generation employs a cable system (dynamic cable system) that uses a floating body that has wind power generation equipment and floats on the sea and a cable (dynamic cable) that connects to the wind power generation equipment.

[0003] In a cable system using a free-hanging method in which the cable is installed directly from a floating body to the seabed, the cable undergoes repeated underwater shape (linear) changes, tension fluctuations, and curvature fluctuations over a long period of time due to the floating body's motion caused by waves and currents.In particular, near the point where the cable lands on the seabed, localized bending (extreme bending) during rough weather and repeated bending over a long period of time pose problems for the cable's bending fatigue durability.

[0004] Conventionally, cables have been proposed that use a twisted structure to reduce bending strain and strain changes due to mechanical history (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6229916 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology described in Patent Document 1 does not focus on the area near the bottom where fatigue is severe, but rather reduces strain changes due to bending strain and mechanical history of the cable by using a twisted structure. However, such a twisted structure causes wear with the seabed near the bottom where the cable hits the bottom, making it difficult to improve the durability of the cable. Therefore, there is a demand for a technology that can improve the durability of cables.

[0007] The present invention has been made in view of the above, and an object of the present invention is to provide a cable and a dynamic cable system that can improve durability. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the cable of the present invention comprises at least one power line and a covering body that surrounds the at least one power line, and a first range in the longitudinal direction of the at least one power line and the covering body has higher bending rigidity than other ranges.

[0009] In addition, in the cable of the present invention, in the above invention, the coating has an outermost layer sheath located at the outermost layer, and the first range of the inner layer of the outermost layer sheath in the coating is set to have a thickness dimension larger than the other ranges.

[0010] In addition, in the cable of the present invention, in the above invention, the coating has an outermost layer sheath located at the outermost layer, and the first range of the outermost layer sheath in the coating is set to have a thickness dimension larger than the other ranges.

[0011] In addition, in the cable of the present invention, in the above invention, the coating has an outermost layer sheath located at the outermost layer, and the first range of the outermost layer sheath in the coating is made of a material having a higher elastic modulus than the other ranges.

[0012] Furthermore, the cable of the present invention comprises a cable main body having at least one power line and a covering body that covers the periphery of the at least one power line, and a reinforcing member that covers the periphery of a first range in the longitudinal direction of the cable main body and reinforces the cable main body to increase the bending rigidity of the first range more than other ranges, and at least both ends in the longitudinal direction of the reinforcing member are fixed to the cable main body.

[0013] In the cable according to the present invention, in the above invention, the reinforcing member has a constant outer diameter at least at a central portion in the longitudinal direction of the reinforcing member.

[0014] In addition, in the cable of the present invention, in the above invention, the reinforcing member has a pair of reinforcing sections formed as two separate pieces in a plane including a central axis along the longitudinal direction of the reinforcing member, and is fixed to the cable main body by combining the pair of reinforcing sections.

[0015] In addition, the cable system of the present invention comprises a floating body having a power facility and floating on the sea, and a cable connected to the power facility, the cable comprising at least one power line and a covering body surrounding the at least one power line, and a first range in the longitudinal direction of the at least one power line and the covering body having higher bending rigidity than other ranges.

[0016] In the cable system according to the present invention, the first range is a range including a bottom landing point on the seabed.

[0017] In the cable system according to the present invention, the first range is a range of 7 m or more and 30 m or less, including the bottom landing point.

[0018] Furthermore, the cable system of the present invention comprises a floating body having a power facility and floating on the sea, and a cable connected to the power facility, wherein the cable comprises a cable main body having at least one power line and a covering body surrounding the at least one power line, and a reinforcing member that covers the periphery of a first range in the longitudinal direction of the cable main body and reinforces the cable main body, thereby increasing the bending rigidity of the first range more than other ranges, and at least both ends in the longitudinal direction of the reinforcing member are fixed to the cable main body.

[0019] In the cable system according to the present invention, the first range is a range including a bottom landing point on the seabed.

[0020] In the cable system according to the present invention, the first range is a range of 7 m or more and 30 m or less, including the bottom landing point. [Effects of the Invention]

[0021] The cable and dynamic cable system according to the present invention have the advantage of being able to improve the durability of the cable. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram schematically showing a wind farm that employs a cable system according to an embodiment. [Figure 2] FIG. 2 is an external view of the cable system. [Figure 3] FIG. 3 is a cross-sectional view of the cable. [Figure 4] FIG. 4 is a diagram illustrating a first range in the longitudinal direction of the cable. [Figure 5] FIG. 5 is a diagram illustrating the first range in the longitudinal direction of the cable. [Figure 6] FIG. 6 is a diagram illustrating the first range in the longitudinal direction of the cable. [Figure 7]FIG. 7 is a diagram showing the configuration of a conventional bend stiffener. [Figure 8] FIG. 8 is a diagram showing the configuration of a conventional bend restrictor. [Figure 9] FIG. 9 is a diagram illustrating a first modification of the embodiment. [Figure 10] FIG. 10 is a diagram illustrating a second modification of the embodiment. [Figure 11] FIG. 11 is a diagram illustrating a third modification of the embodiment. [Figure 12] FIG. 12 is a diagram illustrating a fourth modification of the embodiment. [Figure 13] FIG. 13 is a diagram illustrating a fourth modification of the embodiment. [Figure 14] FIG. 14 is a diagram illustrating a fifth modification of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, with reference to the drawings, a description will be given of a mode for carrying out the present invention (hereinafter, referred to as an embodiment). Note that the present invention is not limited to the embodiment described below. Furthermore, in the drawings, the same parts are given the same reference numerals. Furthermore, the drawings are schematic, and the dimensional relationships and ratios of the elements may differ from the actual situation. Furthermore, the drawings may include parts whose dimensional relationships and ratios differ from each other.

[0024] [Outline of wind farm configuration] FIG. 1 is a diagram schematically illustrating a wind farm WF that employs a cable system 100 according to an embodiment. As shown in Fig. 1, the wind farm WF is a series-connected wind farm that generates wind power offshore, and is a wind farm in which multiple offshore platforms 1 equipped with generators are connected in series by cables 2. Electricity generated on the offshore platforms 1, which are an example of an offshore wind power generation facility, is sent to a substation via the power-transmitting cables 2. The offshore platforms 1 and the cables 2 correspond to a cable system 100 (Fig. 1) according to the present invention.

[0025] [Offshore platform configuration] The offshore platform 1 is a tension-moored platform known as a TLP (Tension Leg Platform). As shown in Fig. 2, the offshore platform 1 comprises a floating body 11, a tower 12, a nacelle 13, a rotor 14, blades 14a, tendons 15, and a foundation 16. The floating body 11, which is forcibly semi-submerged, is connected to the foundation 16 installed on the seabed by the tendons 15, and the offshore platform 1 is moored using tension generated by buoyancy.

[0026] A nacelle 13 is provided on top of a tower 12 mounted on the floating body 11. A yaw drive device is provided at the joint between the nacelle 13 and the tower 12, which rotates the nacelle 13 around the central axis of the tower 12 in accordance with the wind direction. The nacelle 13 supports a main shaft (not shown), to which a rotor 14 having blades 14a is attached. A generator (not shown) is housed within the nacelle 13. The main shaft of the rotor 14 is connected to the rotating shaft of the generator via a gearbox. The nacelle 13 also houses a power facility 13a (FIG. 2) for supplying power generated by the generator to the cable 2, a wind direction and anemometer, a computer device for communicating with a land-based monitoring device that monitors the offshore platform 1, and the like.

[0027] [Cable configuration] Fig. 3 is a cross-sectional view of the cable 2. Specifically, Fig. 3 is a cross-sectional view of the cable 2 cut along a plane perpendicular to the longitudinal direction of the cable 2. Note that Fig. 3 is a cross-sectional view of a range in the longitudinal direction of the cable 2 other than a first range Ar, which will be described later. In this embodiment, the cable 2 is a so-called dynamic cable. As shown in Fig. 3, the cable 2 mainly includes a power line unit 21 and a cover 22 that surrounds the power line unit 21.

[0028] As shown in FIG. 3 , the power line unit 21 is a three-core power cable formed by twisting together three power lines 211. Note that the power line unit 21 may also have a single-core configuration consisting of a single power line 211. Although not specifically shown in the drawings, this power line 211 is composed of, in order from the center, a conductor, an inner semiconductive layer provided on the outer periphery of the conductor, an insulating layer provided on the outer periphery of the inner semiconductive layer, an outer semiconductive layer provided on the outer periphery of the insulating layer, a metal sheath provided on the outer periphery of the outer semiconductive layer, and an inner sheath provided on the outer periphery of the metal sheath. Note that the power line 211 is not limited to the above-mentioned configuration, and other configurations may be adopted as long as at least the conductor is covered with an insulator.

[0029] As shown in FIG. 3, the covering 22 includes a first pressure tape 221 surrounding the power line unit 21, a first seat 222 attached to the outer periphery of the first pressure tape 221, a first wire armor 223 made of iron wire attached to the outer periphery of the first seat 222, a second seat 224 attached to the outer periphery of the first wire armor 223, a second wire armor 225 made of iron wire attached to the outer periphery of the second seat 224, a second pressure tape 226 attached to the outer periphery of the second wire armor 225, and an outermost sheath 227 attached to the outer periphery of the second pressure tape 226. The first and second seats 222 and 224 are made of, for example, plastic cord. The covering 22 is not limited to a double-layered wire armor, and may be a single-layered sheath.

[0030] 3, the gap formed between the power line unit 21 and the covering 22 is filled with a filler 23 made of, for example, a polypropylene string. Three optical cables 24 are arranged in the filler 23.

[0031] In this embodiment, the cable 2 has a different shape between the first range Ar in the longitudinal direction and the other ranges.

[0032] [Regarding the first range in the longitudinal direction of the cable] 4 to 6 are diagrams illustrating the first area Ar in the longitudinal direction of the cable 2. Specifically, FIG. 4 is a diagram schematically illustrating the cable 2 resting on the seabed. FIG. 5 is a side view showing the outer shape of the first area Ar in the longitudinal direction of the cable 2. FIG. 6 is a cross-sectional view corresponding to FIG. 3, showing the first area Ar in the longitudinal direction of the cable 2. In this embodiment, the first range Ar in the longitudinal direction of the cable 2 is set to have higher bending rigidity than other ranges. Here, the first range Ar is a range that includes the bottom landing point of the cable 2 on the seabed, as shown in Fig. 4. The optimal length of the first range Ar will be explained in the section "Optimal Length of the First Range" below.

[0033] Specifically, in the cable 2, the first region Ar of the second pressure tape 226, which is the inner layer of the outermost sheath 227 of the jacket 22, is set to have a larger thickness dimension than the other regions (FIG. 3), as shown in FIGS. 5 and 6. As a result, in the cable 2, the first region Ar is set to have a higher bending rigidity than the other regions.

[0034] [Regarding the optimal length of the first range] Next, the optimum length of the first range Ar will be described. In a cable system 100 used at a water depth of 70 m, the maximum curvature near the bottom landing point obtained from the analysis of cable behavior under rough weather conditions was measured for the cable 2 according to the present embodiment, which is a 66 kV dynamic cable, with the stiffness of the first range Ar increased by 20% compared to the other ranges. The results are shown in Tables 1 and 2 below.

[0035] [Table 1]

[0036] [Table 2]

[0037] The first ranges in Tables 1 and 2 mean the following: "None" means that the first range Ar is not provided. In other words, the cable 2 with "none" has the cross section shown in Figure 3 at any position in its longitudinal direction. Furthermore, "bottom landing point ±2.5m" refers to the range from a position 2.5m above the bottom landing point (Figure 4) to a position 2.5m below the bottom landing point (Figure 4). Furthermore, "bottom landing point -10m" refers to the range from the bottom landing point to a position 10m above the bottom landing point. Furthermore, "bottom landing point +10m" refers to the range from the bottom landing point to a position 10m below the bottom landing point. Furthermore, "bottom landing point +5m ±10m" refers to the range from a position 5m below the bottom landing point as the center to a position 10m above the center to a position 10m below the center.

[0038] The results in Tables 1 and 2 show that the effect of reducing maximum curvature was observed when the first range Ar was set to a range of "settling point ±3.5 m" or more, and when it was set to "settling point ±5 m," the maximum curvature was reduced to 82.4% compared to "none." Even if the first range Ar was expanded to "settling point ±10 m" or "settling point ±15 m," the effect was the same as "settling point ±5 m." Therefore, it was found that the most efficient first range Ar was "settling point ±5 m." Furthermore, even if the center position was shifted about 5 m downward from the landing point, an effect equivalent to "settling point ±5 m" could be obtained if the first range Ar was about 20 to 30 m. Therefore, it was found that the optimal length of the first range Ar was 7 to 30 m, including the bottom landing point.

[0039] According to the present embodiment described above, the following effects are achieved. In the cable 2 according to this embodiment, attention is focused on the vicinity of the bottom landing point, which is an area where fatigue is severe, and the bending rigidity of the first range Ar including the bottom landing point is set higher than that of other ranges. This improves the bending fatigue durability of the cable 2 against local bending in rough weather and repeated bending over a long period of time. Furthermore, since the cable does not have a twisted structure like the cable described in Patent Document 1, it is possible to suppress abrasion between the cable and the seabed near the bottom landing point. Therefore, the cable 2 according to this embodiment can improve durability.

[0040] In particular, the bending rigidity of the first area Ar is made higher than that of other areas by increasing the thickness of the second pressure tape 226, which is the inner layer of the outermost sheath 227 of the jacket 22. Therefore, by increasing the thickness of the outer layer (second pressure tape 226), which is the component that determines the bending rigidity of the cable 2, the bending rigidity of the first area Ar can be made higher than that of other areas easily and efficiently.

[0041] FIG. 7 is a diagram showing the configuration of a conventional bend stiffener 200. As shown in FIG. As a configuration for suppressing bending of the cable 2, a bend stiffener 200 as shown in FIG. 7 is known. The bend stiffener 200 has an elongated shape and has a through-hole that penetrates from one end to the other on a central axis along the longitudinal direction. As shown in FIG. 7, the outer diameter of the bend stiffener 200 continuously decreases from one end to the other. The cable 2 is inserted into the bend stiffener 200 with one end fixed to a specific member. In other words, the bend stiffener 200 is not fixed to the cable 2. Bending of the cable 2 is suppressed within the range where the bend stiffener 200 is provided.

[0042] However, when the bend stiffener 200 is used, the cable 2 needs to be inserted through the bend stiffener 200 when constructing the cable system 100, which makes construction less efficient. In contrast, in the cable 2 according to this embodiment, the bending rigidity in the first range Ar can be increased more than in other ranges without using a separate bend stiffener 200, thereby improving workability.

[0043] FIG. 8 is a diagram showing the configuration of a conventional bend restrictor 300. As shown in FIG. As a configuration for restricting bending of the cable 2, a bend restrictor 300 as shown in FIG. 8 is known. 8, this bend restrictor 300 includes a long, flexible cylindrical member 301 and a plurality of circular members 302 attached to the outer surface of the cylindrical member 301 at predetermined intervals along the longitudinal direction of the cylindrical member 301. The bend restrictor 300 has one end fixed to a specific member, and the cable 2 is inserted into the cylindrical member 301. In other words, the bend restrictor 300 is not fixed to the cable 2. The bending of the cable 2 is restricted by the abutment of adjacent circular members 302 within the area where the bend restrictor 300 is provided.

[0044] However, when the bend restrictor 300 is used, the cable 2 must be inserted through the bend restrictor 300 when installing the cable system 100, which makes installation less efficient. In contrast, in the cable 2 of this embodiment, the bending rigidity in the first range Ar can be made higher than in other ranges without using a separate bend restrictor 300, thereby improving workability.

[0045] (Other embodiments) Although the embodiments for carrying out the present invention have been described above, the present invention should not be limited to only the above-described embodiments. In the above-described embodiment, the cable and cable system of the present invention were adopted in a configuration for generating wind power offshore, but this is not limited to this, and the cable and cable system of the present invention may also be adopted in other power generation configurations.

[0046] In the above-described embodiment, the cable and cable system according to the present invention are employed in a free-hanging configuration in which the cable is installed directly on the seabed from the floating body 11, but this is not limiting. The cable and cable system according to the present invention may also be employed in a lazy wave configuration in which a buoy is provided midway along the cable.

[0047] In the above-described embodiment, the cable according to the present invention is a dynamic cable, but this is not limiting. The cable according to the present invention may be an umbilical cable or a flexible riser pipe used in seabed mineral resource development or subseafloor CO2 storage (CCS: Carbon dioxide Capture and Storage).

[0048] In the above-described embodiment, the position of the first range Ar is not limited to the vicinity of the bottom landing point, but may be the vicinity of the pull-in position to the floating body 11.

[0049] In addition, the following modified examples 1 to 5 may be adopted.

[0050] (Variation 1) Fig. 9 is a diagram illustrating a first modification of the embodiment. Specifically, Fig. 9 is a cross-sectional view corresponding to Fig. 6, showing a first range Ar in the longitudinal direction of the cable 2 according to the first modification. In the first range Ar in the longitudinal direction of the cable 2 according to the present modification 1, the outermost sheath 227 of the jacket 22 is set to have a larger thickness dimension than the other ranges (FIG. 3), as shown in FIG. 9. As a result, the bending rigidity of the cable 2 is set to be higher in the first range Ar than in the other ranges.

[0051] Even when the cable 2 according to the first modification described above is employed, the same effects as those of the above-described embodiment are achieved.

[0052] (Variation 2) Fig. 10 is a diagram illustrating a modified example 2 of the embodiment. Specifically, Fig. 10 is a cross-sectional view corresponding to Fig. 6, showing a first range Ar in the longitudinal direction of the cable 2 according to the modified example 2. In the first range Ar in the longitudinal direction of the cable 2 according to the present modified example 2, both the outermost sheath 227 and the second pressing tape 226 of the coating 22 are set to have a larger thickness than in the other ranges (FIG. 3), as shown in Fig. 10. As a result, the bending rigidity of the cable 2 in the first range Ar is set to be higher than that of the other ranges.

[0053] Even when the cable 2 according to the second modification described above is employed, the same effects as those of the above-described embodiment are achieved.

[0054] (Variation 3) Fig. 11 is a diagram illustrating a third modification of the embodiment. Specifically, Fig. 11 is a side view corresponding to Fig. 5, showing a first area Ar in the longitudinal direction of the cable 2 according to the third modification. For ease of explanation, the first area Ar of the cable 2 is marked with a dot in Fig. 11. In the cable 2 according to the third modification, the first region Ar of the outermost sheath 227 in the jacket 22 is made of a material having a higher elastic modulus than the other regions. For example, in the outermost sheath 227, the other regions are made of a low- to medium-density polyethylene material, and the first region Ar is made of a high-density polyethylene material that is highly compatible with the other regions. As a result, in the cable 2, the first region Ar is set to have a higher bending rigidity than the other regions.

[0055] Even when the cable 2 according to the third modification described above is employed, the same effects as those of the above-described embodiment are achieved. As in the above-described first or second modification, a configuration in which the thickness of the outermost sheath 227 or the like is increased and a configuration in which the material is changed as in the present third modification may be combined.

[0056] (Variation 4) 12 and 13 are diagrams illustrating a fourth modification of the embodiment. Specifically, FIG. 12 is a side view corresponding to FIG. 5, and is a side view of a first range Ar in the longitudinal direction of a cable 2A according to the fourth modification. Note that, for ease of explanation, a dot is added to the first range Ar of the cable 2A in FIG. 12. FIG. 13 is a side view showing a state in which one of a pair of reinforcing portions 401 has been removed. Note that, for ease of explanation, FIG. 13 shows a state in which one of a pair of cable ties 402 has been attached. As shown in FIGS. 12 and 13, a cable 2A according to the fourth modification includes the cable 2 described in the above embodiment and a reinforcing member 400. As shown in FIG.

[0057] The cable 2 according to this fourth modification corresponds to the cable main body according to the present invention. Hereinafter, the cable 2 according to this fourth modification will be referred to as the cable main body 2. The cross section of the cable main body 2 is as shown in FIG. 3 at any position in its longitudinal direction. That is, unlike the above-described embodiment, the thickness dimension of the second pressing tape 226 in the cable main body 2 is constant at any position in its longitudinal direction.

[0058] 12 and 13, the reinforcing member 400 covers the periphery of a first area Ar in the longitudinal direction of the cable main 2 and reinforces the cable main 2, thereby increasing the bending rigidity of the first area Ar more than other areas. As shown in Fig. 13, the reinforcing member 400 includes a pair of reinforcing portions 401 (only one is shown in Fig. 13) and a pair of binding bands 402 (only one is shown in Fig. 13).

[0059] The pair of reinforcing portions 401 are made of a material having an elastic modulus equal to or greater than that of the outermost sheath 227, and when combined, have a cylindrical shape with an inner diameter substantially equal to the outer diameter of the outermost sheath 227. That is, the outer diameter of at least the central portion of the reinforcing member 400 in the longitudinal direction is set constant. Furthermore, the pair of reinforcing portions 401 desirably have excellent abrasion resistance and are desirably made of a medium- to high-density polyethylene material, hard polyurethane, or the like. More specifically, the pair of reinforcing portions 401 are formed by dividing a cylindrical member having an inner diameter substantially equal to the outer diameter of the outermost sheath 227 into two pieces along a plane including the central axis of the cylindrical member. Furthermore, as shown in FIG. 13 , annular grooves 401a are formed on both longitudinal ends of the outer surfaces of the pair of reinforcing portions 401, recessed toward the central axis and extending circumferentially around the central axis. The pair of reinforcing parts 401 are fixed to the cable main 2 by attaching a binding band 402 to the groove 401a in a combined state. That is, the reinforcing member 400 is fixed to the cable main 2 at both ends.

[0060] According to the fourth modification described above, in addition to the same effects as those of the above-described embodiment, the following effects are achieved. The cable 2A according to the present fourth modification includes the above-described reinforcing member 400. Both ends of the reinforcing member 400 are fixed to the cable main body 2. This prevents longitudinal positional deviation between the reinforcing member 400 and the cable main body 2, and allows the reinforcing member 400 to be stably maintained at a position in the cable main body 2 where it is desired to increase the bending rigidity.

[0061] In particular, the reinforcing member 400 includes a pair of reinforcing parts 401 formed as two separate pieces on a plane including a central axis along the longitudinal direction of the reinforcing member 400, and is fixed to the cable main body 2 by combining the pair of reinforcing parts 401. Therefore, the reinforcing member 400 can be easily attached to a position in the cable main body 2 where it is desired to increase the bending rigidity, thereby improving workability.

[0062] (Variation 5) Fig. 14 is a diagram illustrating a fifth modification of the embodiment. Specifically, Fig. 14 is a side view corresponding to Fig. 13, showing a state in which one of a pair of reinforcing portions 401 in cable 2A according to this fifth modification has been removed. For ease of explanation, Fig. 14 shows a state in which one of a pair of cable ties 402 has been attached. In the above-described fourth modification, it is sufficient that the outer diameter of at least the central portion in the longitudinal direction of the reinforcing member 400 is set constant. That is, as in the fifth modification shown in Fig. 14, both end portions of the pair of reinforcing parts 401 may be formed in a tapered shape such that the outer diameter decreases toward the end.

[0063] Even when the reinforcing member 400 according to the fifth modification described above is employed, the same effects as those of the fourth modification described above can be achieved. [Explanation of symbols]

[0064] 1. Offshore Platform 2 Cable (cable body) 2A cable 11 Floating body 12. Tower 13 Nacelle 13a Power equipment 14 rotors 14a blade 15 Tendon 16 Basics 21 Power Line Unit 22 Covering 23 Intervention 24 Optical Cable 100 Cable System 200 Bend Stifna 211 Power Lines 221 First pressure tape 222 First Seat 223 First Wire Armor 224 Second Seat 225 Second Wire Armor 226 Second pressure tape 227 Outermost sheath 300 Bend Restrictor 301 Cylindrical members 302 Circular member 400 Reinforcement member 401 Reinforcement 401a Groove 402 Cable Ties Ar First Range WF Wind Farm

Claims

1. at least one power line; a covering covering the at least one power line, A first range in the longitudinal direction of the at least one power line and the covering body is Cable with higher bending stiffness than other ranges.

2. The coating body is an outermost sheath positioned at the outermost layer; The first area of ​​the inner layer of the outermost sheath in the covering body is The cable according to claim 1 , wherein the thickness dimension is set to be larger than the other range.

3. The coating body is an outermost sheath positioned at the outermost layer; The first region of the outermost sheath of the covering body is The cable according to claim 1 , wherein the thickness dimension is set to be larger than the other range.

4. The coating body is an outermost sheath positioned at the outermost layer; The first region of the outermost sheath of the covering body is The cable according to claim 1 , which is made of a material having a modulus of elasticity higher than the other range.

5. a cable body including at least one power line and a covering covering the at least one power line; a reinforcing member that covers a periphery of a first region in the longitudinal direction of the cable main and reinforces the cable main to increase the bending rigidity of the first region compared to other regions, The reinforcing member is A cable in which at least both longitudinal ends of the reinforcing member are fixed to the cable main body.

6. The reinforcing member is 6. The cable according to claim 5, wherein the outer diameter of at least the central portion in the longitudinal direction of the reinforcing member is set to be constant.

7. The reinforcing member is The cable according to claim 5, further comprising a pair of reinforcing portions formed as two separate pieces in a plane including a central axis along the longitudinal direction of the reinforcing member, and the cable is fixed to the cable main body by combining the pair of reinforcing portions.

8. a floating body having power equipment and floating on the sea; a cable connected to the power equipment; The cable at least one power line; a covering covering the at least one power line, A first range in the longitudinal direction of the at least one power line and the covering body is A cable system with higher bending stiffness than the rest of the range.

9. The first range is The cable system according to claim 8, which has a range including a bottom landing point on the seabed.

10. The first range is The cable system according to claim 9, which has a length in the range of 7 m to 30 m including the bottom landing point.

11. a floating body having power equipment and floating on the sea; a cable connected to the power equipment; The cable a cable body including at least one power line and a covering covering the at least one power line; a reinforcing member that covers a periphery of a first region in the longitudinal direction of the cable main and reinforces the cable main to increase the bending rigidity of the first region compared to other regions, The reinforcing member is A cable system in which at least both longitudinal ends of the reinforcing member are fixed to the cable body.

12. The first range is The cable system according to claim 11, which has a range including a bottom landing point on the seabed.

13. The first range is The cable system according to claim 12, which has a length in the range of 7 m to 30 m including the bottom landing point.

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