submarine cables

Abstract

The present invention relates to the field of offshore wind power technology, and provides a submarine cable comprising: a central pipe, a first electrical unit, a second electrical unit, and a third electrical unit; the central pipe is used to be filled with a cooling medium; the first electrical unit is coated on the outside of the central pipe, the first electrical unit includes a first phase conductor layer, the first phase conductor layer includes a plurality of first phase conductors; the second electrical unit is coated on the outside of the first electrical unit, the second electrical unit includes a second phase conductor layer, the second phase conductor layer includes a plurality of second phase conductors; the third electrical unit is coated on the outside of the second electrical unit, the third electrical unit includes a third phase conductor layer, the third phase conductor layer includes a plurality of third phase conductors, and the first phase conductor, the second phase conductor, and the third phase conductor are spirally wound. The above-mentioned submarine cable reduces the influence of the skin effect, reduces the resistance of the conductor, improves the current carrying capacity, and realizes the use of a smaller conductor cross-section to meet the demand for a larger transmission capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power, and in particular to a submarine cable. Background Art

[0002] With economic development, global energy demand is increasing. In addition to reducing energy consumption through the adoption of new technologies and products, accelerating the development and utilization of oil and gas resources and renewable energy sources is crucial. Electric power development is gradually transitioning toward low-carbon development. Wind energy, as a renewable energy source, is a key component of this transition. In recent years, the development of offshore fixed wind turbines has reached saturation, with approximately 80% of offshore wind energy resources located in waters deeper than 60 meters. Wind energy development is gradually shifting to deeper waters. As a system for capturing offshore wind energy, floating offshore wind turbines are an inevitable trend in the future development of offshore wind power.

[0003] With the success of the world's first commercial floating wind power project, offshore floating wind platforms have garnered widespread attention worldwide. Countries are actively enacting policies related to offshore wind energy development, and the wind energy market in both developed and developing countries is experiencing steady growth. According to reports from the Global Wind Energy Association, Explore Floating Wind Energy, and Wind Europe, the number of offshore wind power installations is projected to grow at an average annual rate of over 16%, reaching 12 GW by 2030. The global number of floating wind turbines is projected to reach 50 by 2022, increasing to 1,500 by 2030. The development of floating offshore wind platforms will boost demand for dynamic submarine cable systems, with the market expected to reach hundreds of billions of yuan in the future.

[0004] However, in existing floating wind power systems, dynamic submarine cables all have a three-core structure, and each phase conductor is composed of multiple single wires twisted together. When current is transmitted, due to the electromagnetic induction effect, the current distribution inside the conductor is uneven, and the current is concentrated on the surface of the conductor, which increases the resistance of the conductor and reduces the transmission efficiency. This requires a very large submarine cable cross-section to achieve a higher transmission capacity, which will cause the submarine cable cross-section to increase, resulting in an increase in the material cost, supporting accessories cost and construction cost of the dynamic submarine cable itself. Summary of the Invention

[0005] The present invention provides a submarine cable for overcoming the defect in the prior art that the cross section of the submarine cable needs to be increased in order to achieve a higher transmission capacity, thereby increasing the cost of the submarine cable.

[0006] The present invention provides a submarine cable, comprising: a central pipe; a cooling medium filled in the central pipe; a first electrical unit, coated on the outside of the central pipe, the first electrical unit including a first phase conductor layer, the first phase conductor layer including a plurality of first phase conductors, the plurality of first phase conductors being spirally wound around the outside of the central pipe; a second electrical unit, coated on the outside of the first electrical unit, the second electrical unit including a second phase conductor layer, the second phase conductor layer including a plurality of second phase conductors, the plurality of second phase conductors being spirally wound around the outside of the first electrical unit; and a third electrical unit, coated on the outside of the second electrical unit, the third electrical unit including a third phase conductor layer, the third phase conductor layer including a plurality of third phase conductors, the plurality of third phase conductors being spirally wound around the outside of the second electrical unit.

[0007] According to a submarine cable provided by the present invention, a first dielectric is provided between the monofilaments of the first phase conductor, a second dielectric is provided between the monofilaments of the second phase conductor, and a third dielectric is provided between the monofilaments of the third phase conductor.

[0008] According to a submarine cable provided by the present invention, the first electrical unit further includes: a first phase conductor shielding layer, a first phase insulating layer and a first phase insulating shielding layer sequentially coated from the inside to the outside, wherein the first phase conductor shielding layer is coated outside the first phase conductor layer.

[0009] According to a submarine cable provided by the present invention, the second electrical unit further includes: a second phase conductor shielding layer, a second phase insulation layer and a second phase insulation shielding layer sequentially covered from the inside to the outside, wherein the second phase conductor shielding layer is covered outside the second phase conductor layer.

[0010] According to a submarine cable provided by the present invention, the third electrical unit further includes: a third phase conductor shielding layer, a third phase insulation layer and a third phase insulation shielding layer sequentially wrapped from the inside to the outside, wherein the third phase conductor shielding layer is wrapped outside the third phase conductor layer.

[0011] According to the present invention, a submarine cable further includes a metal shielding layer, which is coated outside the third electrical unit; the submarine cable has a dynamic application mode and a static application mode. When the submarine cable is in the dynamic application mode, the metal shielding layer adopts a wrapped structure or a longitudinally wrapped welded corrugated structure; when the submarine cable is in the static application mode, the metal shielding layer adopts an alloy lead sheath.

[0012] The submarine cable provided by the present invention further includes a first sheath layer, which is coated outside the metal shielding layer.

[0013] According to the present invention, a submarine cable further includes an armor structure, which is coated outside the first sheath layer, wherein the armor structure includes multiple armor layers; when the submarine cable is in the dynamic application mode, the armor structure includes an even number of armor layers, and the spiral directions of adjacent armor layers are opposite.

[0014] According to a submarine cable provided by the present invention, when the submarine cable is in the static application mode, the armor structure includes an odd number of armor layers, and the outer armor layer is a polypropylene rope.

[0015] The submarine cable provided by the present invention further includes a second sheath layer, which is coated outside the armor structure.

[0016] The submarine cable provided by the present invention changes the direction of current flow, reduces the influence of the skin effect, reduces the resistance of the conductor, and improves the current carrying capacity by spirally arranging the conductor in each phase electrical unit. This achieves the goal of meeting the demand for larger transmission capacity with a smaller conductor cross-section. The outer diameter and weight of the submarine cable are significantly smaller than those of conventional submarine cables, greatly reducing material costs, production costs, and construction and installation costs. The central pipeline is provided to provide a more suitable temperature environment for the operation of the submarine cable, significantly improving the operating conditions of the submarine cable and increasing the current carrying capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a structural schematic diagram of the submarine cable provided by the present invention;

[0019] Reference numerals:

[0020] 10: Central pipe; 11: Cooling medium; 20: First electrical unit; 21: First phase conductor layer; 22: First dielectric; 23: First phase conductor shielding layer; 24: First phase insulation layer; 25: First phase insulation shielding layer; 30: Second electrical unit; 31: Second phase conductor layer; 32: Second dielectric; 33: Second phase conductor shielding layer; 34: Second phase insulation layer; 35: Second phase insulation shielding layer; 40: Third electrical unit; 41: Third phase conductor layer; 42: Third dielectric; 43: Third phase conductor shielding layer; 44: Third phase insulation layer; 45: Third phase insulation shielding layer; 50: Metal shielding layer; 60: First sheath layer; 70: Armor structure; 71: First armor layer; 72: First tape layer; 73: Second armor layer; 74: Second tape layer; 80: Second sheath layer. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0022] The features of the terms "first" and "second" in the description and claims of the present invention may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0023] The following combination Figure 1 A submarine cable according to the present invention is described.

[0024] like Figure 1 As shown, in an embodiment of the present invention, a submarine cable includes: a central pipe 10, a first electrical unit 20, a second electrical unit 30, and a third electrical unit 40. The central pipe 10 is filled with a cooling medium 11. The first electrical unit 20 is coated on the outside of the central pipe 10 and includes a first phase conductor layer 21, which includes a plurality of first phase conductors, which are spirally wound around the outside of the central pipe 10. The second electrical unit 30 is coated on the outside of the first electrical unit 20 and includes a second phase conductor layer 31, which includes a plurality of second phase conductors, which are spirally wound around the outside of the first electrical unit 20. The third electrical unit 40 is coated on the outside of the second electrical unit 30 and includes a third phase conductor layer 41, which includes a plurality of third phase conductors, which are spirally wound around the outside of the second electrical unit 30.

[0025] Specifically, a central conduit 10 is provided at the center of the submarine cable, into which a cooling medium 11 is injected. The cooling medium 11 can be a coolant or a cooling gas, which dissipates heat during operation of the submarine cable, thereby improving its current carrying capacity. In this embodiment, three electrical units are sequentially wrapped around the exterior of the central conduit 10. The first phase conductor within the first electrical unit 20 is arranged in a circular pattern along the circumference of the central conduit 10 using a spiral winding method; the second phase conductor within the second electrical unit 30 is also arranged in a circular pattern along the circumference of the first electrical unit 20 using a spiral winding method; and the third phase conductor within the third electrical unit 40 is also arranged in a circular pattern along the circumference of the second electrical unit 30 using a spiral winding method. Furthermore, the cross-sectional areas of the first, second, and third phase conductors are equal. Each phase conductor is composed of multiple twisted strands of monofilaments. The diameter, number, and spacing of the monofilaments within each phase conductor can be adjusted accordingly based on actual conditions.

[0026] Furthermore, in this embodiment, by spirally winding each phase conductor, the influence of the skin effect is reduced, thereby reducing the resistance of the conductor.

[0027] Optionally, in an embodiment of the present invention, the central pipe 10 is made of metal material, and its structure can be a longitudinally welded pipe, an integrally formed pipe, or a spirally wound and woven metal wire.

[0028] Furthermore, in embodiments of the present invention, submarine cables can be used not only in static but also in dynamic applications. The conductor cross-section can be specifically configured according to application requirements to meet transmission capacity. The conductor can be made of copper, aluminum, copper alloy, aluminum alloy, or other materials. Specifically, when the conductor is made of an alloy material, the base element, i.e., copper or aluminum, should contain no less than 50%. By adjusting the content of other alloying elements such as carbon, zinc, magnesium, phosphorus, nickel, cobalt, and lead, performance that meets dynamic usage requirements can be achieved. Optionally, the specific components can be configured as follows:

[0029] Example 1, 100 parts of matrix elements, 10 parts of zinc, 5 parts of magnesium, 5 parts of nickel, 3 parts of tin, 2 parts of lead, 2 parts of manganese, 0.5 parts of carbon, 0.5 parts of sulfur; 0.5 parts of cobalt;

[0030] Example 2, 100 parts of matrix elements, 5 parts of zinc, 10 parts of magnesium, 5 parts of nickel, 5 parts of tin, 1 part of lead, 1 part of manganese, 0.5 parts of carbon, and 0.5 parts of sulfur;

[0031] Example 3, 100 parts of matrix elements, 10 parts of zinc, 2 parts of magnesium, 5 parts of nickel, 10 parts of tin, 0.5 parts of lead, 0.5 parts of manganese, 0.5 parts of carbon, 0.2 parts of sulfur, and 0.1 parts of phosphorus;

[0032] Example 4, 100 parts of matrix elements, 2 parts of zinc, 5 parts of magnesium, 5 parts of nickel, 5 parts of tin, 0.5 parts of lead, 0.2 parts of manganese, 0.2 parts of carbon, 0.1 parts of sulfur, and 0.1 parts of phosphorus;

[0033] Example 5, 100 parts of matrix elements, 3 parts of zinc, 8 parts of magnesium, 6 parts of nickel, 10 parts of tin, 1 part of lead, 0.1 part of manganese, 0.1 part of carbon, 0.2 part of sulfur, 0.3 part of phosphorus; 0.5 part of cobalt; among which, the components and proportions of other alloy conductor materials can be adjusted according to requirements.

[0034] The submarine cable provided by the embodiment of the present invention reduces the influence of the skin effect, reduces the resistance of the conductor, and improves the current carrying capacity by spirally arranging the conductor in each phase electrical unit. This achieves the goal of meeting the demand for larger transmission capacity with a smaller conductor cross-section. The outer diameter and weight of the submarine cable are significantly smaller than those of conventional submarine cables, greatly reducing material costs, production costs, and construction and installation expenses. The central pipeline is provided to provide a more suitable temperature environment for the operation of the submarine cable, significantly improving the operating conditions of the submarine cable and increasing the current carrying capacity.

[0035] like Figure 1 As shown, in the embodiment of the present invention, a first medium 22 is provided between the monofilaments of the first phase conductor, a second medium 32 is provided between the monofilaments of the second phase conductor, and a third medium 42 is provided between the monofilaments of the third phase conductor.

[0036] Specifically, a dielectric is provided between the filaments of each phase conductor, which can both constrain the position of the filaments and tightly connect the conductor to the structure outside the conductor. Optionally, in an embodiment of the present invention, the first dielectric 22, the second dielectric 32, and the third dielectric 42 can be semi-conductive glue or grease.

[0037] like Figure 1 As shown, in an embodiment of the present invention, the first electrical unit 20 further includes: a first phase conductor shielding layer 23, a first phase insulating layer 24 and a first phase insulating shielding layer 25 sequentially wrapped from the inside to the outside, wherein the first phase conductor shielding layer 23 is wrapped around the outside of the first phase conductor layer 21.

[0038] Specifically, the first phase conductor shielding layer 23 , the first phase insulating layer 24 and the first phase insulating shielding layer 25 are sequentially extruded outside the first phase conductor layer 21 to form sufficient electrical protection for the cable.

[0039] Correspondingly, the second electrical unit 30 also includes: a second phase conductor shielding layer 33, a second phase insulation layer 34 and a second phase insulation shielding layer 35, which are sequentially covered from the inside to the outside, wherein the second phase conductor layer 31 is covered outside the first phase insulation shielding layer 25, and the second phase conductor shielding layer 33 is covered outside the second phase conductor layer 31.

[0040] Specifically, the second phase conductor shielding layer 33 , the second phase insulating layer 34 and the second phase insulating shielding layer 35 are sequentially extruded outside the second phase conductor layer 31 to form sufficient electrical protection for the cable.

[0041] Accordingly, in an embodiment of the present invention, the third electrical unit 40 also includes: a third phase conductor shielding layer 43, a third phase insulation layer 44 and a third phase insulation shielding layer 45 sequentially wrapped from the inside to the outside, wherein the third phase conductor layer 41 is wrapped around the second phase insulation shielding layer 35, and the third phase conductor shielding layer 43 is wrapped around the third phase conductor layer 41.

[0042] Specifically, a third phase conductor shielding layer 43 , a third phase insulating layer 44 and a third phase insulating shielding layer 45 are sequentially extruded outside the third phase conductor layer 41 to form sufficient electrical protection for the cable.

[0043] like Figure 1 As shown, in the embodiment of the present invention, the submarine cable further includes a metal shielding layer 50 , which is coated on the outside of the third electrical unit 40 .

[0044] Specifically, a metal shielding layer 50 is provided outside the third-phase insulating shielding layer 45 to provide a metal shield and carry short-circuit current. Furthermore, in an embodiment of the present invention, the submarine cable has a dynamic application mode and a static application mode. When the submarine cable is in the dynamic application mode, the metal shielding layer 50 employs a wrapped structure or a longitudinally wrapped welded corrugated structure. When the submarine cable is in the static application mode, the metal shielding layer 50 employs an alloy lead sheath.

[0045] Specifically, when the submarine cable is in dynamic use, the metal shielding layer 50 may be wrapped with copper tape, copper wire, copper wire + copper tape, or a corrugated metal sheath, such as a corrugated copper sheath. When the submarine cable is in static use, the metal shielding layer 50 may be an alloy lead sheath.

[0046] like Figure 1 As shown, in the embodiment of the present invention, the submarine cable further includes a first sheath layer 60 , which is coated on the outside of the metal shielding layer 50 .

[0047] Specifically, the first sheath layer 60 can form a covering and mechanical protection for the inner core, and can also play a role in radial water blocking. Optionally, the material of the first sheath layer 60 can be polyethylene or polyurethane.

[0048] like Figure 1As shown, in an embodiment of the present invention, the submarine cable further includes an armor structure 70, which is coated outside the first sheath layer 60. The armor structure 70 includes multiple armor layers. When the submarine cable is in a dynamic application mode, the armor structure 70 includes an even number of armor layers, and the spiral directions of adjacent armor layers are opposite.

[0049] Specifically, in Figure 1 In the illustrated embodiment, the armor structure 70 includes a first armor layer 71, a first tape layer 72, a second armor layer 73, and a second tape layer 74, which are sequentially coated. The first armor layer 71 is coated over the first sheath layer 60. The first tape layer 72 is used to tighten and constrain the first armor layer 71, and the second tape layer 74 is used to tighten and constrain the second armor layer 73. Furthermore, in this embodiment, the number of armor layers is even, and the spiral directions of adjacent armor layers are opposite.

[0050] Furthermore, in the case where the submarine cable is in a static application mode, the armor structure 70 includes an odd number of armor layers, and the outer armor layer is a polypropylene rope.

[0051] Specifically, when submarine cables are used in static conditions, the number of armor layers is odd, and each layer is covered with a corresponding tape layer to tighten and bind the armor layers. The outermost armor layer is made of polypropylene rope.

[0052] like Figure 1 As shown, in the embodiment of the present invention, the submarine cable further includes a second sheath layer 80 , which is coated outside the armor structure 70 .

[0053] Specifically, the second sheath layer 80 is extruded and uniformly coated over the armor structure 70. Its thickness meets the requirements for mechanical protection and water resistance. Furthermore, the second sheath layer 80 is typically a bright, eye-catching yellow or other color for easy underwater identification. A uniformly wide colored stripe is provided along the axial direction to indicate whether the submarine cable has twisted. Optionally, in embodiments of the present invention, the second sheath layer 80 may be made of polyethylene, polyurethane, or other materials.

[0054] The submarine cable provided by the embodiment of the present invention can greatly reduce crosstalk between each circuit by sequentially sheathing three electrical units and transmitting three-phase electricity on the same core, thereby reducing magnetic induction loss in the metal shielding layer and the armor layer. At the same time, during the operation of the submarine cable, when subjected to tension and bending, the three electrical units will not produce contact friction, which can prevent the outer sheath of each electrical unit from wear and deformation.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A submarine cable, characterized in that: include: A central pipe; the central pipe is used to be filled with a cooling medium; a first electrical unit, coated on the outside of the central pipe, the first electrical unit comprising a first phase conductor layer, the first phase conductor layer comprising a plurality of first phase conductors, the plurality of first phase conductors being spirally wound outside the central pipe; a second electrical unit, wrapped around the outside of the first electrical unit, the second electrical unit comprising a second phase conductor layer, the second phase conductor layer comprising a plurality of second phase conductors, the plurality of second phase conductors being spirally wound outside the first electrical unit; a third electrical unit, wrapped around the outside of the second electrical unit, the third electrical unit comprising a third phase conductor layer, the third phase conductor layer comprising a plurality of third phase conductors, the plurality of third phase conductors being spirally wound outside the second electrical unit; The cross-sectional areas of the first phase conductor, the second phase conductor, and the third phase conductor are equal; a first medium is provided between the monofilaments of the first phase conductor; a second medium is provided between the monofilaments of the second phase conductor; and a third medium is provided between the monofilaments of the third phase conductor; the first medium, the second medium, and the third medium are semi-conductive glue or grease.

2. The submarine cable according to claim 1, characterized in that The first electrical unit further includes: a first phase conductor shielding layer, a first phase insulating layer and a first phase insulating shielding layer sequentially wrapped from the inside to the outside, wherein the first phase conductor shielding layer is wrapped outside the first phase conductor layer.

3. The submarine cable according to claim 1, characterized in that The second electrical unit further includes: a second phase conductor shielding layer, a second phase insulating layer, and a second phase insulating shielding layer sequentially covered from the inside to the outside, wherein the second phase conductor shielding layer is covered outside the second phase conductor layer.

4. The submarine cable according to claim 1, characterized in that The third electrical unit further includes: a third phase conductor shielding layer, a third phase insulating layer and a third phase insulating shielding layer sequentially wrapped from the inside to the outside, wherein the third phase conductor shielding layer is wrapped outside the third phase conductor layer.

5. The submarine cable according to claim 1, characterized in that It also includes a metal shielding layer, wherein the metal shielding layer is coated outside the third electrical unit; The submarine cable has a dynamic application mode and a static application mode. When the submarine cable is in the dynamic application mode, the metal shielding layer adopts a wrapped structure or a longitudinally wrapped welded corrugated structure. When the submarine cable is in the static application mode, the metal shielding layer adopts an alloy lead sheath.

6. The submarine cable according to claim 5, characterized in that It also includes a first sheath layer, which is coated outside the metal shielding layer.

7. The submarine cable according to claim 6, characterized in that It also includes an armor structure, which is coated outside the first sheath layer, wherein the armor structure includes multiple armor layers; When the submarine cable is in the dynamic application mode, the armor structure includes an even number of armor layers, and the helical directions of adjacent armor layers are opposite.

8. The submarine cable according to claim 7, characterized in that When the submarine cable is in the static application mode, the armor structure includes an odd number of armor layers, and the outer armor layer is a polypropylene rope.

9. The submarine cable according to claim 7, characterized in that It also includes a second sheath layer, which is coated outside the armor structure.

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