High-temperature pressure-resistant cable for energy storage device and manufacturing method thereof

Abstract

The present invention relates to the technical field of wires and cables, and in particular to a high-temperature and high-voltage cable for an energy storage device and a manufacturing method thereof, comprising: a plurality of wire cores, a flame-retardant filling layer, a sheathing layer, an armor layer and an outer sheath, wherein the wire core comprises a conductor with a circular cross-section, the outer side of the conductor is coated with a protective layer, a gap filling layer is provided between the conductor and the protective layer, and the gap filling layer is formed by filling a plurality of matrices provided with a conductive skin layer and a phase-change heat storage inner layer; the matrix can fill the cuts formed on the outer side of the conductor due to twisting, and the conductive skin layer enables the gap filling layer to conduct electricity, thereby balancing the electric field and avoiding local discharge, and at the same time, through the heat absorption and heat release of the phase-change heat storage inner layer, the heating and cooling rates of the conductor can be slowed down, thereby reducing the influence of high-frequency thermal expansion and contraction on the material, and avoiding the formation of a gap between the conductor and the protective layer due to thermal expansion and contraction.

Description

Technical Field

[0001] The present invention relates to the technical field of wires and cables, and in particular to a high-temperature and high-pressure cable for an energy storage device and a manufacturing method thereof. Background Art

[0002] Small wind turbines have relatively small power and unstable voltage. They must use batteries to store a large amount of electricity before they can be used. Cables are needed to transmit electricity between wind turbines and batteries. Since the conductor is made of multiple twisted wires, the surface of the conductor is uneven, and gaps will appear between the conductor and the insulation layer. Once water vapor invades, it is easy to cause partial discharge of the conductor, resulting in insulation breakdown.

[0003] Traditional cables can balance the electric field and avoid local discharge by setting a semi-conductive shielding layer between the insulation layer and the conductor. However, due to the inconsistent thermal expansion and contraction coefficients of the metal conductor and the semi-conductive shielding layer materials, when the cable conductor heats up and expands and contracts, a gap will still appear between the conductor and the semi-conductive shielding layer. In addition, wind power generation is affected by the environment, and the cables connecting the energy storage devices are powered on and off more frequently. The conductors heat up and cool down more frequently. Correspondingly, a discharge gap is more likely to appear between the conductor and the semi-conductive shielding layer, and the probability of local discharge is higher. Summary of the invention

[0004] In view of the technical problems existing in the conductor and the insulation layer in the prior art, the first aspect of the present invention provides a high-temperature and high-pressure cable for an energy storage device, comprising:

[0005] A plurality of wire cores, each of which comprises a conductor with a circular cross section, and the outer side of the conductor is coated with a protective layer;

[0006] The flame retardant filling layer is filled in the slits formed by the two tangents of the wire cores, and the wire cores and the flame retardant filling layer are wrapped together by the wrapping layer to form a circular cross-sectional shape;

[0007] An armor layer, covering the outer side of the wrapping layer;

[0008] An outer sheath, extruded and wrapped around the outside of the armor layer;

[0009] Wherein, a gap filling layer is provided between the conductor and the protective layer, and the gap filling layer and the conductor are extruded and solidified by the protective layer to form a circular cross-section with a flat outer edge;

[0010] The gap filling layer is formed by filling a plurality of matrices provided with a conductive skin layer and a phase change heat storage inner layer, so that the gap filling layer can conduct electricity and can store heat through phase change;

[0011] A support layer is provided inside the protective layer to resist the tensile force that causes the protective layer to deform due to thermal expansion and contraction, and to maintain the roundness of the outer edge of the gap filling layer.

[0012] Preferably, the protective layer includes an inner shielding layer and an insulating layer which are sequentially coated from the inside to the outside, the inner shielding layer is made of semi-conductive polyolefin material, and the insulating layer is made of high-elasticity and high-temperature resistant fluorosilicone rubber.

[0013] Preferably, the supporting layer is arranged inside the insulating layer, and the inner diameter of the supporting layer is larger than the inner diameter of the insulating layer, and the outer diameter of the supporting layer is smaller than the outer diameter of the insulating layer.

[0014] Preferably, the support layer comprises a resin strip spirally wound in the insulating layer, the spiral winding direction is right-handed, and the winding pitch is 5.0-10.0 mm.

[0015] Preferably, the cross section of the resin strip is arranged to be a parallelogram with a short side and a long side, wherein the short side is parallel to the cable axis, and the long side is arranged at an angle to the cable axis.

[0016] Preferably, the length ratio of the short side to the long side of the resin strip is 1:2.

[0017] Preferably, the matrix is ​​configured as a granular structure with a diameter of 100-200 microns.

[0018] Preferably, the conductive skin layer includes a matrix shell and a conductive coating, a cavity for filling the phase change thermal storage inner layer is formed inside the matrix shell, and the conductive coating is coated on the outside of the matrix shell.

[0019] Preferably, the phase-change heat storage inner layer includes a heat storage filler, and the heat storage filler is filled in a cavity formed inside the matrix shell.

[0020] A second aspect of the present invention provides a method for manufacturing a high-temperature voltage-resistant cable for an energy storage device, comprising the following steps:

[0021] Step S1, conductor twisting, using a wire twisting machine to twist multiple strands of soft silver-plated copper wires or fine aluminum alloy wires into the conductor with a circular cross-section;

[0022] Step S2: extruding the protective layer.

[0023] 2.1. Extruding the inner shielding layer on the outer side of the conductor by using an extruder;

[0024] 2.2. Extruding the insulating layer twice on the outer side of the inner shielding layer by using an extruder. After the first extrusion and cooling, the resin strip is spirally wound on the outer side to form the supporting layer. Then, the second extrusion is performed to extrude the supporting layer into the insulating layer.

[0025] Step S3, making a cable core, arranging multiple strands of cores tangentially, filling the cut seam with glass fiber rope, and then using a wrapping machine to wrap the core and the glass fiber rope with a non-woven tape to form the wrapping layer, the number of wrapping layers of the non-woven tape is four, and the wrapping overlap rate is 15%;

[0026] Step S4, making an armor layer, using a wrapping machine to wrap a layer of aluminum alloy tape on the outside of the wrapping layer to form the armor layer, and the wrapping overlap rate is 25%;

[0027] Step S5, making an outer sheath, using an extruder to extrude low-smoke halogen-free flame-retardant polyolefin on the outer side of the armor layer to form the outer sheath;

[0028] Wherein, in step S2, a gap is left between the conductor and the inner shielding layer, and the gap is filled with a plurality of matrices provided with a conductive skin layer and a phase-change heat storage inner layer to form the gap filling layer.

[0029] Compared with the prior art, the advantages of the high-temperature voltage-resistant cable for energy storage device of the present invention are:

[0030] A gap filling layer is provided between the conductor and the protective layer, and the gap filling layer is formed by filling a plurality of matrices provided with a conductive skin layer and a phase change heat storage inner layer, so that the gap filling layer can be conductive and can phase change heat storage. In this way, the matrix can fill the cut formed by twisting on the outside of the conductor, and the conductive skin layer enables the gap filling layer to be conductive, thereby balancing the electric field and avoiding local discharge. At the same time, through the absorption and release of heat by the phase change heat storage inner layer, the heating and cooling rates of the conductor can be slowed down, thereby reducing the influence of high-frequency thermal expansion and contraction on the material, and avoiding the formation of a gap between the conductor and the protective layer due to thermal expansion and contraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are not intended to be drawn to scale. In the accompanying drawings, each identical or nearly identical component shown in each figure may be represented by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings.

[0032] Figure 1 It is a schematic diagram of the structure of a high-temperature and high-pressure cable for an energy storage device shown in the present invention.

[0033] Figure 2 It is a schematic diagram of the cross-sectional structure of the center line core of the high-temperature and high-pressure cable for the energy storage device shown in the present invention.

[0034] Figure 3 yes Figure 2 Enlarged schematic diagram at point A in the middle.

[0035] Figure 4It is a schematic structural diagram of a matrix in a high-temperature and pressure-resistant cable for an energy storage device shown in the present invention.

[0036] Figure 5 It is a schematic structural diagram of a center line core of a high-temperature and high-pressure cable for an energy storage device shown in the present invention.

[0037] Figure 6 It is a schematic diagram of an axial cross-section of an insulating layer in a high-temperature and high-voltage cable for an energy storage device shown in the present invention.

[0038] In the figure: 1. core; 11. conductor; 12. inner shielding layer; 13. insulation layer; 15. gap filling layer; 151. matrix shell; 152. conductive coating; 153. heat storage filler; 16. support layer; 2. flame retardant filling layer; 3. wrapping layer; 4. armor layer; 5. outer sheath. DETAILED DESCRIPTION

[0039] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0040] Traditional cables can balance the electric field and avoid local discharge by setting a semi-conductive shielding layer between the insulation layer and the conductor. However, due to the inconsistent thermal expansion and contraction coefficients of the metal conductor and the semi-conductive shielding layer materials, when the cable conductor heats up and expands and contracts, a gap will still appear between the conductor and the semi-conductive shielding layer. In addition, wind power generation is affected by the environment, and the cables connecting the energy storage devices are powered on and off more frequently. The conductors heat up and cool down more frequently. Correspondingly, discharge gaps are more likely to appear between the conductor and the semi-conductive shielding layer, and the probability of local discharge is higher. Therefore, how to solve the problem of discharge gaps in materials caused by frequent thermal expansion and contraction of conductors is an urgent problem to be solved.

[0041] Combination Figure 1-Figure 5 As shown, the present invention provides a high-temperature and high-pressure cable for an energy storage device, which mainly includes a plurality of wire cores 1, a flame-retardant filling layer 2, a wrapping layer 3, a steel belt armor layer and an outer sheath 5.

[0042] Combination Figure 1 As shown, the wire core 1 includes a conductor 11 with a circular cross section. The conductor 11 is made of a plurality of annealed copper wires twisted in a 1+6+12 structure, and the inner layer and the outer layer are twisted in opposite directions.

[0043] Furthermore, a protective layer is provided on the outside of the conductor 11, and a gap filling layer 15 is provided between the conductor 11 and the protective layer, and the gap filling layer 15 and the conductor 11 are extruded and solidified by the protective layer to form a circular cross-section with a flat outer edge. The gap filling layer 15 is used to fill the gap on the outer edge of the conductor 11 caused by twisting, so that the outer edge of the conductor 11 is more rounded, thereby avoiding local discharge.

[0044] Combination Figure 4As shown, the gap filling layer 15 is specifically formed by filling a plurality of matrices provided with a conductive skin layer and a phase change heat storage inner layer.

[0045] In a specific embodiment, the matrix is ​​provided as a granular structure having a diameter of 100-200 microns.

[0046] Furthermore, the conductive skin layer includes a matrix shell 151 and a conductive coating 152. A cavity for filling the phase change thermal storage inner layer is formed inside the matrix shell 151. The conductive coating 152 is coated on the outside of the matrix shell 151 so that the matrix contacts each other for electrical conduction.

[0047] In a preferred embodiment, the matrix shell 151 is made of a polymer film, and the conductive coating 152 is made of conductive graphite powder, which not only has good conductivity but also has good lubricity, thereby reducing the friction between the conductor 11 and the protective layer when the cable is bent or twisted.

[0048] In a preferred embodiment, the phase change thermal storage inner layer includes a thermal storage filler 153, which is filled in the cavity formed inside the matrix shell 151. Preferably, the thermal storage filler 153 is a crystalline hydrated salt, and has a large volume thermal storage density and a thermal conductivity greater than that of an organic phase change material.

[0049] In this way, the conductive coating 152 enables the gap filling layer 15 to conduct electricity, balance the electric field, and avoid local discharge. At the same time, the heat storage filler 153 can absorb the heat generated when the conductor 11 is conducting, and slow down the heating rate of the conductor 11. When the conductor 11 is powered off, the phase change heat storage inner layer can release heat and slow down the cooling rate of the conductor 11. The heating and cooling rates of the conductor 11 are slowed down by the phase change heat storage inner layer, thereby reducing the impact of high-frequency thermal expansion and contraction on the material, and avoiding the formation of a gap between the conductor 11 and the protective layer due to thermal expansion and contraction.

[0050] Combination Figure 5 and Figure 6 As shown, a support layer 16 is provided inside the protective layer to resist the tensile force that causes deformation of the protective layer due to thermal expansion and contraction, and to maintain the roundness of the outer edge of the gap filling layer 15 .

[0051] Furthermore, the protective layer includes an inner shielding layer 12 and an insulating layer 13 which are sequentially wrapped from the inside to the outside. The support layer 16 is arranged in the insulating layer 13, and the inner diameter of the support layer 16 is larger than the inner diameter of the insulating layer 13, and the outer diameter of the support layer 16 is smaller than the outer diameter of the insulating layer 13, so that the support layer 16 is completely wrapped inside by the insulating layer 13. The support layer 16 plays a skeleton support role. When the insulating layer 13 expands and contracts due to temperature changes, it can resist the tensile force generated by the expansion / contraction, reduce the deformation amplitude, and avoid the discharge gap outside the gap filling layer 15 due to excessive deformation.

[0052] In a specific embodiment, the support layer 16 includes a resin strip spirally wound in the insulating layer 13, the spiral winding direction is right-handed, and the winding pitch is 5.0-10.0 mm. The spiral resin strip plays a role in skeleton support without affecting the bending performance of the cable.

[0053] Furthermore, the cross-section of the resin strip is arranged as a parallelogram with short sides and long sides, and the short sides are parallel to the cable axis, and the long sides are arranged at an angle to the cable axis. This makes the long sides of the resin strip an inclined surface in the radial direction of the cable. When the insulating layer 13 expands and contracts radially, the resin strip not only resists the deformation force through friction, but the inclined surface can also resist the deformation of the insulating layer 13, thereby improving the effect of resisting deformation.

[0054] In a preferred embodiment, the length ratio of the short side to the long side of the resin strip is 1:2.

[0055] In an optional embodiment, the inner shielding layer 12 is made of semi-conductive polyolefin material, and the insulating layer 13 is made of highly elastic and high-temperature resistant fluorosilicone rubber, which has good insulation and high-temperature resistance, as well as good elasticity and flexibility.

[0056] Combination Figure 1 As shown, multiple wire cores 1 are arranged tangentially in pairs, and the flame retardant filling layer 2 is filled in the cuts formed by the wire cores 1 being tangentially in pairs. The wire cores 1 and the flame retardant filling layer 2 are wrapped together by the wrapping layer 3 to form a circular cross-sectional shape.

[0057] In a specific embodiment, the flame retardant filling layer 2 is filled with glass fiber rope, which not only has good flame retardant properties, but also can increase the tensile strength of the cable. The wrapping layer 3 is a non-woven fabric wrapping layer with four wrapping layers and a wrapping overlap rate of 15%. The non-woven fabric has good high temperature resistance and corrosion resistance, and is soft and will not affect the bending performance of the cable.

[0058] Furthermore, the steel belt armor layer is coated on the outside of the wrapping layer 3, and the outer sheath 5 is extruded on the outside of the steel belt armor layer.

[0059] In a specific embodiment, the armor layer 4 is a corrugated steel belt armor layer, which can play a role in radial compression resistance and improve the radial compression resistance performance of the cable.

[0060] In an optional embodiment, the outer sheath 5 is formed by extrusion of low-smoke halogen-free flame-retardant polyolefin, which has good flame retardancy and produces low smoke when burned by open flame, thus being more environmentally friendly.

[0061] [Manufacturing method of high-temperature and high-pressure cables for energy storage devices]

[0062] A second aspect of the present invention provides a method for manufacturing a high-temperature voltage-resistant cable for an energy storage device, comprising the following steps:

[0063] The following steps are involved:

[0064] Step S1, conductor twisting, using a twisting machine to twist multiple copper wires into a conductor 11 with a circular cross section;

[0065] Step S2: extruding the protective layer.

[0066] 2.1. Extruding an inner shielding layer 12 on the outer side of the conductor 11 by using an extruder;

[0067] 2.2. Extruding the insulating layer 13 twice on the outer side of the inner shielding layer 12 by using an extruder. After the first extrusion and cooling, a resin strip is spirally wound on the outer side to form a supporting layer 16. Then, extruding is performed for the second time so that the supporting layer 16 is extruded into the insulating layer 13.

[0068] Step S3, making a cable core, arranging multiple strands of cores tangentially, filling the cut seam with glass fiber rope, and then using a wrapping machine to wrap the core and the glass fiber rope with a non-woven tape to form a wrapping layer 3, the number of wrapping layers of the non-woven tape is four, and the wrapping coverage rate is 15%;

[0069] Step S4, making an armor layer, using a wrapping machine to wrap a layer of aluminum alloy tape on the outside of the wrapping layer 3, and forming an armor layer 4, with a wrapping overlap rate of 25%;

[0070] Step S5, making an outer sheath, using an extruder to extrude low-smoke halogen-free flame-retardant polyolefin on the outer side of the armor layer 4 to form an outer sheath 5;

[0071] In step S2.1, a gap is left between the conductor 11 and the inner shielding layer 12, and the gap is filled with a plurality of matrices having a conductive skin layer and a phase-change heat storage inner layer to form a gap filling layer 15.

[0072] In this way, the conductive skin layer enables the gap filling layer 15 to conduct electricity, thereby balancing the electric field. At the same time, the phase change heat storage inner layer slows down the heating and cooling rates of the conductor 11, thereby reducing the impact of high-frequency thermal expansion and contraction on the material, thereby avoiding the formation of a gap between the conductor 11 and the protective layer due to thermal expansion and contraction.

[0073] In combination with the above embodiments, a gap filling layer 15 is provided between the conductor 11 and the protective layer, and the gap filling layer 15 is formed by filling a plurality of matrices provided with a conductive skin layer and a phase change heat storage inner layer, so that the gap filling layer 15 can be conductive and can phase change heat storage. In this way, the matrix can fill the cut formed by twisting on the outside of the conductor 11, and the conductive skin layer enables the gap filling layer 15 to be conductive, thereby balancing the electric field and avoiding local discharge. At the same time, through the absorption and release of heat by the phase change heat storage inner layer, the heating and cooling rates of the conductor 11 can be slowed down, thereby reducing the influence of high-frequency thermal expansion and contraction on the material, and avoiding the formation of a gap between the conductor 11 and the protective layer due to thermal expansion and contraction.

[0074] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A high-temperature voltage-resistant cable for an energy storage device, characterized in that: include: A plurality of wire cores (1), wherein the wire core (1) comprises a conductor (11) with a circular cross section, and the outer side of the conductor (11) is coated with a protective layer; The flame retardant filling layer (2) is filled in the cuts formed by the two tangents of the wire cores (1), and the wire cores (1) and the flame retardant filling layer (2) are wrapped together by the wrapping layer (3) to form a cable core with a circular cross-section; An armor layer (4) wrapped around the outer side of the wrapping layer (3); An outer sheath (5) extruded on the outer side of the armor layer (4); Wherein, a gap filling layer (15) is provided between the conductor (11) and the protective layer, and the gap filling layer (15) and the conductor (11) are extruded and solidified by the protective layer to form a circular cross-section with a flat outer edge; The gap filling layer (15) is formed by filling a plurality of matrices provided with a conductive skin layer and a phase change heat storage inner layer, so that the gap filling layer (15) can conduct electricity and can perform phase change heat storage; A support layer (16) is provided inside the protective layer, which is used to resist the tensile force that causes the protective layer to deform due to thermal expansion and contraction, and to maintain the roundness of the outer edge of the gap filling layer (15).

2. The high-temperature voltage-resistant cable for energy storage device according to claim 1, characterized in that: The protective layer comprises an inner shielding layer (12) and an insulating layer (13) which are sequentially coated from the inside to the outside, the inner shielding layer (12) is made of semi-conductive polyolefin material, and the insulating layer (13) is made of high-elasticity and high-temperature resistant fluorosilicone rubber.

3. The high-temperature voltage-resistant cable for energy storage device according to claim 2, characterized in that: The support layer (16) is arranged inside the insulating layer (13), and the inner diameter of the support layer (16) is larger than the inner diameter of the insulating layer (13), and the outer diameter of the support layer (16) is smaller than the outer diameter of the insulating layer (13).

4. The high-temperature voltage-resistant cable for energy storage device according to claim 2, characterized in that: The support layer (16) comprises a resin strip spirally wound in the insulating layer (13), the spiral winding direction is right-handed, and the winding pitch is 5.0-10.0 mm.

5. The high-temperature voltage-resistant cable for energy storage device according to claim 4, characterized in that: The cross section of the resin strip is arranged to be a parallelogram with a short side and a long side, wherein the short side is parallel to the cable axis, and the long side is arranged at an angle to the cable axis.

6. The high-temperature voltage-resistant cable for energy storage device according to claim 4, characterized in that: The length ratio of the short side to the long side of the resin strip is 1:

2.

7. The high-temperature voltage-resistant cable for energy storage device according to claim 6, characterized in that: The matrix is ​​provided as a granular structure with a diameter of 100-200 microns.

8. The high-temperature and high-pressure cable for energy storage device according to claim 1, characterized in that: The conductive skin layer comprises a matrix shell (151) and a conductive coating (152); a cavity for filling a phase-change heat storage inner layer is formed inside the matrix shell (151); and the conductive coating (152) is coated on the outside of the matrix shell (151).

9. The high-temperature voltage-resistant cable for energy storage device according to claim 8, characterized in that: The phase-change heat storage inner layer comprises a heat storage filler (153), and the heat storage filler (153) is filled in a cavity formed inside the matrix shell (151).

10. A method for manufacturing a high-temperature and high-pressure cable for an energy storage device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step S1, conductor twisting, using a twisting machine to twist multiple strands of soft silver-plated copper wires or fine aluminum alloy wires into the conductor (11) with a circular cross section; Step S2: extruding the protective layer. 2.

1. Extruding an inner shielding layer (12) on the outer side of the conductor (11) using an extruder; 2.

2. Extruding the insulating layer (13) twice on the outer side of the inner shielding layer (12) by using an extruder. After the first extrusion and cooling, a resin strip is spirally wound on the outer side to form the supporting layer (16). Then, the second extrusion is performed so that the supporting layer (16) is extruded into the insulating layer (13). Step S3, making a cable core, arranging multiple strands of wire cores tangentially, filling the cut seam with glass fiber rope, and then using a wrapping machine to wrap the wire core and the glass fiber rope with a non-woven fabric tape to form the wrapping layer (3), the number of wrapping layers of the non-woven fabric tape is four, and the wrapping overlap rate is 15%; Step S4, manufacturing an armor layer, using a wrapping machine to wrap a layer of aluminum alloy tape on the outside of the wrapping layer (3), and forming the armor layer (4), with a wrapping overlap rate of 25%; Step S5, making an outer sheath, using an extruder to extrude low-smoke halogen-free flame-retardant polyolefin on the outer side of the armor layer (4) to form the outer sheath (5); in, In step S2, a gap is left between the conductor (11) and the inner shielding layer (12), and the gap is filled with a plurality of matrices having a conductive skin layer and a phase-change heat storage inner layer to form the gap filling layer (15).

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