Composite middle-high voltage wind energy cable

Abstract

The utility model discloses a composite middle-high voltage wind energy cable. The composite middle-high voltage wind energy cable comprises a composite cable core and an outer sheath wrapping the outer side of the composite cable core. The composite cable core comprises three power units, two ground wire units and a control unit which are arranged in a stranded manner; each power unit comprises a power line conductor, a conductor shielding layer, a high-voltage insulating layer and an insulation shielding layer which are sequentially arranged from inside to outside; the ground wire unit comprises a ground wire conductor and a shielding layer which are sequentially arranged from inside to outside; the insulation shielding layer is provided with a control line conductor, a control line insulation layer, a control line sheath, a metal shielding layer and a semi-conductive shielding layer, and the metal shielding layer is also used as a ground wire.

Description

TECHNICAL FIELD

[0001] The utility model relates to a cable structure especially relates to a composite medium and high voltage wind energy cable. BACKGROUND

[0002] The development of offshore wind power is a global trend, and countries are actively promoting the development of offshore wind power. With the development of deep sea technology, the proportion of high-power wind turbine generators is increasing, and the maximum capacity has reached more than 20MW. Among them, high-power wind turbine generators use a medium and high voltage power cable instead of dozens of low voltage power cables, improve the output efficiency of the fan, reduce the line loss, and thus reduce the production cost.

[0003] The torsional medium and high voltage power wind energy cable used in the fan tower drum is matched with the control cable, which is laid from the top transformer side to the bottom switch cabinet. The power cable and the control cable are laid together, and during the fan yaw process, the cable will be twisted. The outer diameter of the medium and high voltage wind energy cable reaches more than 100mm, and the outer diameter of the control cable is generally 8-15mm. In the use process, it is affected by the extrusion and repeated torsional bending of the power cable, and the cable core breakage problem is easy to occur, which causes the fan to be unable to operate normally, causing great economic loss. SUMMARY

[0004] The utility model overcomes the insufficient of prior art, provides a composite medium and high voltage wind energy cable.

[0005] The cable integrates the control unit in the medium and high voltage cable structure to avoid the core breakage problem caused by the mutual extrusion of the traditional power cable and the control cable. The torsion-resistant ground wire unit and the multi-strand thin wire stranded conductor structure are adopted to further improve the flexibility and service life of the cable.

[0006] To achieve the above purpose, the utility model adopts the technical scheme that:

[0007] A composite medium and high voltage wind energy cable, comprising a composite cable core and an outer sheath wrapped outside the composite cable core, the composite cable core comprising three power units, two ground wire units and one control unit arranged in a twisted manner, the power unit comprising a power line conductor, a conductor shielding layer, a high voltage insulation layer and an insulation shielding layer arranged in sequence from inside to outside, the ground wire unit comprising a ground wire conductor and a shielding layer arranged in sequence from inside to outside, the insulation shielding layer being provided with a control line conductor, a control line insulation layer, a control line sheath, a metal shielding layer and a semi-conductive shielding layer, and the metal shielding layer serving as a ground wire.

[0008] Further specifically, any power unit is tangentially arranged with the other two power units, and two ground wire units and a control unit are uniformly arranged outside the three power units, any ground wire unit is tangentially arranged with the two power units, and the control unit is tangentially arranged with the two power units.

[0009] Further specifically, the control line conductor is arranged as a 5-class tinned copper conductor, and the diameter of the tinned copper monofilament is arranged as 0.2-0.31 mm.

[0010] Further specifically, the control line insulating layer is arranged as an ethylene-propylene rubber insulating material.

[0011] Further specifically, the control line sheath is arranged as a low-smoke halogen-free rubber material.

[0012] Further specifically, the metal shielding layer is arranged as an aluminum alloy metal shielding layer.

[0013] Further specifically, the ground wire conductor adopts a 5-class aluminum alloy conductor, and the diameter of the aluminum alloy monofilament is arranged as 0.2-0.51 mm.

[0014] Further specifically, the power line conductor adopts a 5-class tinned copper conductor, and the diameter of the tinned copper monofilament is arranged as 0.3-0.51 mm.

[0015] Further specifically, the shielding layer is arranged as a semi-conductive shielding layer, and the conductor shielding layer is also arranged as a semi-conductive shielding layer.

[0016] Further specifically, the high-voltage insulating layer is arranged as an ethylene-propylene rubber insulating material, and the insulating shielding layer is arranged as a semi-conductive shielding layer.

[0017] Further specifically, the outer sheath is arranged as a low-smoke halogen-free flame-retardant rubber material.

[0018] The utility model solves the defects in the background art, and has the following beneficial effects:

[0019] By integrating the control line unit, the power unit and the ground wire unit, mutual extrusion and wear during separate wiring are effectively avoided, wiring space and material cost are reduced, 5-class tinned copper conductors and aluminum alloy ground wire conductors are adopted, corrosion resistance, torsion resistance and high-voltage insulation requirements in marine environments are considered, and the reliability and economy of the cable as a whole are greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] The utility model will be further described below in combination with the drawings and examples;

[0021] Figure 1 is the sectional structure schematic diagram of the utility model;

[0022] Figure 2 is a sectional view structure schematic diagram of the power unit of the utility model;

[0023] Figure 3 is a sectional view structure schematic diagram of the ground wire unit of the utility model;

[0024] Figure 4 is a sectional view structure schematic diagram of the control unit of the utility model;

[0025] In the drawing: 1, power unit; 11, power line conductor; 12, conductor shielding layer; 13, high voltage insulation layer; 14, insulation shielding layer; 2, ground wire unit; 21, ground wire conductor; 22, shielding layer; 3, control unit; 31, control line conductor; 32, control line insulation layer; 33, control line sheath; 34, metal shielding layer; 35, semi-conductive shielding layer; 4, outer sheath. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the utility model clearer, the technical scheme in the utility model embodiment will be described in more detail below in combination with the drawings in the utility model embodiment. In the drawings, the same or similar notations represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the utility model, not all. The embodiments described below by reference to the drawings are exemplary and are intended to explain the utility model, and cannot be understood as limiting the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the utility model.

[0027] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the utility model. The embodiments of the utility model will be described in detail below in combination with the drawings.

[0028] It should be understood that the drawings are only used to exemplarily illustrate the present application.

[0029] The utility model will now be described in further detail in combination with the drawings and embodiments, and these drawings are all simplified schematic diagrams, only schematically showing the basic structure of the utility model, and therefore only show the relevant constitution of the utility model.

[0030] A composite medium- and high-voltage wind power cable, such as Figure 1 As shown, the cable includes a composite cable core and an outer sheath 4 covering the outside of the composite cable core. The composite cable core includes three twisted power units 1, two ground units 2, and one control unit 3. Each power unit 1 is tangentially arranged to the other two power units 1. The two ground units 2 and the control unit 3 are evenly arranged outside the three power units 1. Each ground unit 2 is tangentially arranged to the two power units 1, and the control unit 3 is tangentially arranged to the two power units 1. Replacing one of the original three ground units 2 with a control unit 3 solves the problem of easy breakage of the control wire while ensuring that the cable size remains unchanged.

[0031] like Figure 1 , Figure 2 As shown, the power unit 1 includes a power line conductor 11, a conductor shielding layer 12, a high voltage insulation layer 13, and an insulation shielding layer 14 arranged sequentially from the inside to the outside.

[0032] The power line conductor 11 is a type 5 tin-plated copper conductor, which is composed of several monofilaments. The diameter of each tin-plated copper monofilament is set to 0.3~0.51mm, and the elongation at break is not less than 20%. By using a type 5 tin-plated copper conductor formed by stranding multiple monofilaments, sufficient current carrying capacity can be guaranteed in medium and high voltage applications, and the flexibility and fatigue resistance under torsion and tension conditions can be enhanced. The tin plating process can effectively prevent oxidation and corrosion of the conductor caused by the high humidity environment inside the wind turbine tower. The elongation at break of not less than 20% can further reduce the risk of core wire breakage caused by repeated torsion and bending during yaw.

[0033] The conductor shielding layer 12 is configured as a semi-conductive conductor shielding layer, which is configured as a semi-conductive nylon tape wrapped around the outside of the power line conductor 11. By wrapping the power unit 1 with semi-conductive shielding material, a uniform electric field distribution on the conductor surface and insulation interface can be achieved, reducing the risk of partial discharge caused by electric field concentration in medium and high voltage scenarios, thereby extending the overall service life of the cable in the torsional environment of the wind turbine tower. The semi-conductive shielding material has excellent conductivity and adhesion, and when used in conjunction with the ethylene propylene rubber high-voltage insulation layer 13, it can further enhance the insulation reliability of the cable and provide stable electrical protection for the cable in deep-sea environments.

[0034] The high-voltage insulation layer 13 is made of ethylene-propylene rubber insulation material, and the insulation shielding layer 14 is made of semi-conductive insulation shielding layer. Further, the high-voltage insulation layer 13 is made of medium-high-voltage clean ethylene-propylene rubber insulation material, with tensile strength ≥8.5Mpa and elongation at break ≥300%. By using ethylene-propylene rubber insulation material outside the power unit 1, high dielectric strength and good aging resistance are achieved, which can effectively improve the insulation reliability of the cable in a medium-high-voltage environment, and at the same time, the core has excellent elasticity and toughness in repeated torsion conditions. In combination with the semi-conductive insulation shielding layer outside, the electric field is more uniformly distributed along the surface of the core, further reducing the risk of partial discharge and power loss, and maintaining safe and stable transmission characteristics when the fan tower is yawing. In combination with the structure design in the torsion environment as described above, the cooperation of the high-voltage insulation layer 13 and the insulation shielding layer 14 effectively enhances the service life and electrical performance of the whole composite cable in the long-term operation of the offshore wind turbine, reducing downtime and maintenance costs.

[0035] As shown in Figure 1 , Figure 3 , the ground wire unit 2 comprises a ground wire conductor 21 and a shielding layer 22 arranged from inside to outside.

[0036] The ground wire conductor 21 is made of 5-type aluminum alloy conductor, with the diameter of the aluminum alloy monofilament being 0.2-0.51mm, the tensile strength of the monofilament being 98-159Mpa, and the elongation at break being not less than 10%. By selecting a plurality of monofilament aluminum alloy conductors and controlling the diameter of the monofilament within the range of 0.2-0.51mm, not only can the cross section of the ground wire conductor 21 be flexibly designed according to the fault current capacity, but also the mechanical strength and conductivity can be maintained at a high level in a long-term torsion environment. Since the specific gravity of aluminum alloy is less than that of copper and has strong corrosion resistance, even if a small amount of monofilament breakage occurs in a long-term torsion and high-humidity environment, it will not significantly affect the ground wire function and the overall service life of the cable. This structure also significantly reduces the weight of the cable and the cost of materials, making the installation of the composite medium-high-voltage wind energy cable in the tower of a deep-sea wind turbine more convenient, and ensuring good torsion resistance and operation safety during the yawing process of the fan.

[0037] The shielding layer 22 is made of semi-conductive shielding material. By extruding the semi-conductive shielding material outside the ground wire unit 2, the electric field on the surface of the conductor and the insulation interface can be uniformly distributed, reducing the risk of partial discharge caused by electric field concentration in a medium-high-voltage environment, thereby prolonging the service life of the cable in a torsion environment of the fan tower.

[0038] As shown in Figure 1 , Figure 4As shown, the control unit 3 comprises, from inside to outside, a control line conductor 31, a control line insulation layer 32, a control line sheath 33, a metal shielding layer 34, and a semi-conductive shielding layer 35, wherein the metal shielding layer 34 also serves as a ground wire.

[0039] The control line conductor 31 is a 5-class tinned copper conductor composed of a plurality of tinned copper filaments, with a diameter of 0.2-0.31 mm and an elongation at break of not less than 20%. By using a 5-class tinned copper conductor and controlling the filament diameter within the range of 0.2-0.31 mm, the control line conductor 31 has a multi-stranded thin wire structure, which provides better flexibility and bending resistance under the working conditions of fan yawing and cable twisting, and the tinning process can effectively reduce the risk of oxidation and corrosion in the high-humidity marine environment, thereby further improving the reliability of control signal transmission and reducing the possibility of core wire breakage.

[0040] The control line insulation layer 32 is made of ethylene-propylene rubber insulation material with a tensile strength of ≥6.5 Mpa and an elongation at break of ≥200%. By using ethylene-propylene rubber insulation, the control line core can maintain high elasticity and toughness under the long-term twisting and bending conditions of offshore wind turbines, and the material has good insulation properties and aging resistance in medium and high voltage environments, which can effectively improve the safety and service life of the control circuit and maintain stable electrical performance in a humid marine environment.

[0041] An ethylene-propylene rubber insulation layer is extruded on the outside of the tinned copper conductor to form an insulated core, and four insulated cores are twisted into a cable and wrapped with a layer of non-woven fabric on the outside, and a control line sheath 33 is extruded on the outside of the non-woven fabric.

[0042] The control line sheath 33 is made of low-smoke and halogen-free rubber material. By extruding a low-smoke and halogen-free rubber sheath on the twisted control line insulation core, the smoke and toxic gas emissions during combustion can be significantly reduced while meeting the mechanical strength requirements, and the fire safety factor in the tower of an offshore wind turbine can be effectively improved, meeting environmental and flame retardant requirements, thereby providing higher protection for equipment and personnel in the event of a fire or short circuit failure, and complying with relevant environmental and safety standards.

[0043] The metal shielding layer 34 is provided as an aluminum alloy metal shielding layer. A plurality of aluminum alloy monofilaments are twisted into a bundle and uniformly wound outside the control line sheath 33 to form the aluminum alloy metal shielding layer, which serves as a ground wire, can realize effective electromagnetic shielding of the control line, reduce the overall weight and material cost, and realize both ground wire and control line; the aluminum alloy has good corrosion resistance and torsion resistance, is suitable for the harsh environment of high humidity and frequent yaw in the offshore wind turbine tower, and can balance the functions of the ground wire and the protection performance during long-term use, effectively improving the overall electrical safety and economy of the cable.

[0044] A semiconductive shielding layer 35 is extruded on the outside of the aluminum alloy metal shielding layer.

[0045] Three power units 1, two ground wire units 2, and one control unit 3 are twisted to form a composite cable core, and a layer of non-woven fabric is wrapped outside the composite cable core to effectively tighten the composite cable core and prevent the composite cable core from loosening. An outer sheath 4 is provided outside the non-woven fabric.

[0046] The outer sheath 4 is provided as a low-smoke halogen-free flame-retardant rubber material, wherein the tensile strength is ≥10 N / mm 2 , the elongation at break is ≥200%, and the tear strength is ≥5 N / mm. By extruding a low-smoke halogen-free flame-retardant rubber sheath outside the composite cable core, the tensile strength, elongation at break, and tear strength can meet the torsion and bending requirements in the offshore wind turbine tower while significantly reducing the amount of smoke and toxic gas emissions generated by the cable in the event of a fire or failure, and improving the flame-retardant safety performance. The design of the outer sheath 4 can resist salt spray corrosion and other adverse weather conditions in deep sea environments, providing more reliable comprehensive protection for the power units 1, ground wire units 2, and control units 3 inside the cable, thereby prolonging the service life of the cable and reducing the risk of downtime for maintenance.

[0047] In combination with the use requirements of the cable in the high-power fan tower under torsion conditions, the control unit 3 is combined with the power unit 1 and the ground wire unit 2 to form a composite cable core, which avoids the mutual extrusion and wear during the torsion process when the traditional power cable and control cable are laid separately. The three power units 1, two ground wire units 2, and one control unit 3 are arranged in a "3+2+1" arrangement and are coated with a low-smoke halogen-free flame-retardant material to form an outer sheath 4, which can meet the medium and high voltage transmission performance while improving the overall bending resistance and torsion resistance of the cable.

[0048] Through reasonable arrangement of the ground wire unit 2 and integrated design of the control unit 3 and the power unit 1, comprehensive wiring of power transmission and control signal transmission can be realized in limited space, the laying process is simplified and the cost is reduced, and the mutual extrusion risk of internal cores can be effectively reduced during fan yawing; when the power core with a large outer diameter and the control core with a relatively small outer diameter are coaxially distributed in the same cable core structure, the tightness and flexibility between the cores can be improved by twisting design, so that stable electrical performance can be maintained in a long-term repeated twisting environment. The cable has good insulation and shielding performance, and can also consider fault protection and electromagnetic compatibility, thereby significantly reducing the risk of shutdown and maintenance of the wind turbine. Based on the above structure, the service life can be effectively prolonged in actual operation in the tower of the offshore wind turbine, and the reliability and economy of the wind power cable in high-power and deep-sea environments can be improved.

[0049] The composite medium-high voltage wind power cable of the utility model meets the demand of medium-high voltage power transmission in offshore wind turbine, successfully integrates the control unit 3 in the same cable, significantly reduces the risk of core breakage caused by mutual extrusion of the power unit 1 and the control unit 3, the ground wire unit 2 adopts aluminum alloy conductor, the cross section can be designed according to the fault current capacity, the weight and material cost of the cable are reduced while meeting the safety requirements, the overall low-smoke halogen-free flame-retardant sheath and each core wire adopt torsion-resistant materials and shielding structures, ensuring the operation safety and long-term reliability of the cable in harsh marine environment and fan yawing conditions, and providing efficient and stable power and control transmission for high-power wind turbines.

[0050] According to the above description, related personnel can make various changes and modifications without deviating from the technical concept of the utility model. The technical scope of the utility model is not limited to the content in the specification, and must be determined according to the scope of claims.

[0051] The preferred embodiments of the utility model are described in detail above in combination with the drawings, but the utility model is not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical scheme of the utility model within the technical concept of the utility model, and these simple modifications all belong to the protection scope of the utility model.

[0052] In addition, it should be noted that various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the utility model will not further describe various possible combination manners.

[0053] In addition, various different embodiments of the present application can be combined arbitrarily, as long as they do not violate the spirit of the present application, and should be considered as disclosed by the present application.

Claims

1. A composite medium-high voltage wind power cable, characterized in that: The composite cable core and an outer sheath (4) covering the composite cable core; The composite cable core comprises three power units (1), two ground wire units (2) and one control unit (3) arranged in a twisted manner; The power unit (1) comprises, from inside to outside, a power line conductor (11), a conductor shielding layer (12), a high-voltage insulation layer (13) and an insulation shielding layer (14); The ground wire unit (2) comprises, from inside to outside, a ground wire conductor (21) and a shielding layer (22); The control unit (3) comprises, from inside to outside, a control line conductor (31), a control line insulation layer (32), a control line sheath (33), a metal shielding layer (34) and a semi-conductive shielding layer (35), wherein the metal shielding layer (34) serves as a ground wire.

2. The composite medium-high voltage air energy cable according to claim 1, characterized in that: Any power unit (1) is tangentially arranged with the other two power units (1), and the two ground wire units (2) and the control unit (3) are uniformly arranged outside the three power units (1), any ground wire unit (2) is tangentially arranged with the two power units (1), and the control unit (3) is tangentially arranged with the two power units (1).

3. The composite medium-high voltage air energy cable according to claim 1, characterized in that: The control line conductor (31) is a 5-class tinned copper conductor, and the diameter of the tinned copper monofilament is 0.2-0.31 mm.

4. The composite medium-high voltage air energy cable of claim 1, wherein: The control line insulation layer (32) is an ethylene-propylene rubber insulation material, and the control line sheath (33) is a low-smoke halogen-free rubber material.

5. The composite medium-high voltage air energy cable of claim 1, wherein: The metal shielding layer (34) is an aluminum alloy metal shielding layer.

6. The composite medium-high voltage air energy cable of claim 1, wherein: The ground wire conductor (21) is a 5-class aluminum alloy conductor, and the diameter of the aluminum alloy monofilament is 0.2-0.51 mm.

7. The composite medium-high voltage air energy cable of claim 1, wherein: The power line conductor (11) is a 5-class tinned copper conductor, and the diameter of the tinned copper monofilament is 0.3-0.51 mm.

8. The composite medium-high voltage air energy cable of claim 1, wherein: The shielding layer (22) is a semi-conductive shielding material, and the conductor shielding layer (12) is a semi-conductive conductor shielding layer.

9. The composite medium-high voltage air energy cable of claim 1, wherein: The high-voltage insulation layer (13) is an ethylene-propylene rubber insulation material, and the insulation shielding layer (14) is a semi-conductive insulation shielding layer.

10. The composite medium-high voltage air energy cable of claim 1, wherein: The outer sheath (4) is a low-smoke halogen-free flame-retardant rubber material.

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