Filling strip and intelligent long-life XLPE insulated power cable

Abstract

The invention discloses a filling strip and an intelligent long-life XLPE insulated power cable, and belongs to the technical field of power cables, the device comprises a first supporting part, a connecting part and a second supporting part which are connected in sequence; the first supporting parts and the second supporting parts are arranged at intervals; the first supporting part and the second supporting part are arranged in an axial symmetry mode. Compared with an existing solid filling strip, the filling strip is provided with the first supporting part, the connecting part and the second supporting part which are connected in sequence, and the semi-closed storage space is formed among the first supporting part, the connecting part and the second supporting part, so that structural support is provided for subsequently placing a corresponding temperature measuring module in the filling strip; and a corresponding deformation space can be provided for the temperature measurement module, so that the temperature measurement module is prevented from being damaged in the cable laying process.

Description

Technical Field

[0001] The invention belongs to the technical field of power cables, and in particular relates to a filling strip and an intelligent long-life XLPE insulated power cable. Background Art

[0002] In recent years, medium-voltage cross-linked polyethylene insulated power cables have been widely used in power systems. In order to ensure the stability of power supply, it is necessary to monitor the temperature of each structural layer during the operation of medium- and high-voltage insulated power cables. Fiber optic temperature sensing, as a new technology, has begun to be used and promoted in China, such as the bundled submarine transmission cable disclosed in the Chinese invention patent with application number 202011097473.X. The cable includes multiple transmission cable units and fiber optic temperature measurement units. All transmission cable units are twisted into a cable, and a first gap filling material is filled between the twisted transmission cable units and the fiber optic temperature measurement units. The outer surface temperature of the insulation is measured by optical fiber, and the real-time temperature of the conductor can be calculated without considering the ambient temperature outside the cable, thereby providing guidance for timely regulation of the cable current carrying capacity, so that the cable can maximize its transmission capacity and avoid damage to the cable due to overload.

[0003] However, in actual use, it was found that the shape of the cable needs to be randomly adjusted according to the complexity of the terrain when it is laid, so the cable often needs to be bent to varying degrees; because the gap between the transmission cable unit and the optical fiber temperature measurement unit is completely filled with relevant materials, the deformation space left for the optical fiber temperature measurement unit is very limited, and it is easy to be damaged by excessive squeezing, thereby affecting the normal temperature monitoring work. Summary of the invention

[0004] The technical problem to be solved by the present invention is: how to provide an intelligent long-life XLPE insulated power cable to improve the stability of temperature monitoring.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A filling strip comprises a first supporting portion, a connecting portion and a second supporting portion which are connected in sequence; The first supporting portion and the second supporting portion are arranged at an interval; The first supporting portion and the second supporting portion are arranged in an axisymmetric manner.

[0006] Furthermore, the present invention also provides an intelligent long-life XLPE insulated power cable, comprising a conductor, a temperature measuring optical cable, an inner sheath, an outer sheath and at least three of the above-mentioned filling strips; The filling strips are evenly distributed in the inner sheath along the circumference of the inner sheath; The second arc segment and the inner wall of the inner sheath are arranged opposite to each other; The filling strip is filled and arranged between the conductor and the inner wall of the inner sheath; The filling strip and part of the inner wall of the inner sheath together form a space for placing the temperature measuring optical cable; The outer side surface of the conductor is in close contact with the first arc segment; The outer portion of the inner sheath is sleeved with an outer sheath.

[0007] The beneficial effect of the present invention is that compared with the existing solid filling strip, the filling strip provided by the present invention is arranged to be a first supporting part, a connecting part and a second supporting part which are connected in sequence, and a semi-enclosed storage space is formed between the first supporting part, the connecting part and the second supporting part, thereby not only providing structural support for the subsequent placement of the corresponding temperature measuring module inside the filling strip, but also providing a corresponding deformation space for the temperature measuring module, thereby avoiding damage to the temperature measuring module during the cable laying process. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a structural schematic diagram of a filling strip according to a specific embodiment of the present invention; Figure 2 It is a cross-sectional view of an intelligent long-life XLPE insulated power cable according to a specific embodiment of the present invention; Description of labels: 1. Filling strip; 11. First supporting portion; 12. Connecting portion; 13. Second supporting portion; 14. Storage space; 15. First arc segment; 16. Second arc segment; 17. Connecting segment; 2. Conductor; 3. Temperature measurement optical cable; 4. Non-woven fabric; 5. Inner sheath; 6. Armor layer; 7. Outer sheath. DETAILED DESCRIPTION

[0009] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0010] The most critical concept of the present invention is that the filling strip is arranged to be a first supporting part, a connecting part and a second supporting part which are connected in sequence, and a semi-enclosed storage space is formed between the first supporting part, the connecting part and the second supporting part, thereby not only providing structural support for the subsequent placement of the temperature measuring module in the filling strip, but also providing a corresponding deformation space for the temperature measuring module, thereby avoiding damage to the temperature measuring module during the cable laying process.

[0011] Please refer to Figure 1 to Figure 2 , the filling strip provided by the present invention comprises a first supporting portion 11, a connecting portion 12 and a second supporting portion 13 connected in sequence; The first supporting portion 11 and the second supporting portion 13 are arranged at intervals; The first support portion 11 and the second support portion 13 are arranged axially symmetrically.

[0012] Specifically, the filler strip is a continuous structure like the cable.

[0013] From the above description, it can be seen that the beneficial effect of the present invention is that: in order to make the power cable have a temperature measurement function, the existing power cables only consider how to embed the temperature measurement module inside the cable during the design and manufacturing process. Therefore, it is often chosen to directly fill the corresponding filling strips between the temperature measurement module and the battery core to ensure that the temperature measurement module can be stably fixed inside the cable, but it does not consider whether the temperature measurement module will be damaged by bending of the cable during the laying process, which will ultimately affect the temperature measurement effect; to solve this problem, the present invention arranges the filling strip 1 into a first supporting part 11, a connecting part 12 and a second supporting part 13 connected in sequence, and a semi-enclosed storage space 14 is formed between the first supporting part 11, the connecting part 12 and the second supporting part 13, thereby not only providing structural support for the subsequent placement of the corresponding temperature measurement module inside the filling strip, but also providing a corresponding deformation space for the temperature measurement module, thereby avoiding damage to the temperature measurement module during the cable laying process.

[0014] Furthermore, the first support portion 11 and the second support portion 13 are both provided with a first arc segment 15; The connecting portion 12 is arc-shaped; The first arc segment 15 of the first supporting portion 11 , the connecting portion 12 and the first arc segment 15 of the second supporting portion 13 form a saddle structure.

[0015] From the above description, it can be seen that since the filling strip and the corresponding battery cell need to be used in combination, and the battery cell is usually cylindrical, in order to make the filling strip and the battery cell adapt to each other, the part where the filling strip of the present invention contacts the battery cell is set to a saddle shape, so that the battery cell and the filling strip can fit tightly, thereby compressing the volume of the cable and making the internal structure of the cable more compact and stable.

[0016] Furthermore, the first support portion 11 and the second support portion 13 are both provided with a second arc segment 16; The second arc segment 16 of the first support portion 11 and the second arc segment 16 of the second support portion 13 are both arranged on a side away from the saddle structure.

[0017] Furthermore, the center of the second arc segment 16 of the first support portion 11 coincides with the center of the second arc segment 16 of the second support portion 13 .

[0018] From the above description, it can be seen that after the filling strips and the battery cores cooperate with each other to form a multi-core structure, it is usually necessary to cover the outside of the multi-core structure with a corresponding protective layer. In order to make the cabled structure closer to a cylinder, a corresponding second arc segment 16 is provided on the filling strip, and it is ensured that the centers of all the second arc segments 16 coincide, so that the additional side arc surfaces of the multiple combined filling strips can form a complete circular surface, thereby ensuring the twisting roundness.

[0019] Furthermore, the first support portion 11 and the second support portion 13 further include a connecting section 17; The first arc segment 15, the second arc segment 16 and the connecting segment 17 form a hollow structure; The connection point between the first arc segment 15 and the connection segment 17 is connected to the connection portion 12 .

[0020] From the above description, it can be seen that, without affecting the first support part 11 and the second support part 13 and the supporting performance, by setting the first support part 11 and the second support part 13 as a hollow structure, not only the manufacturing cost of the filling strip can be effectively reduced, but also the weight of the finished cable can be greatly reduced, thereby effectively reducing the difficulty of laying the cable.

[0021] The present invention also provides an intelligent long-life XLPE insulated power cable, comprising a conductor 2, a temperature measuring optical cable 3, an inner sheath 5, an outer sheath 7 and at least three of the above-mentioned filling strips 1; Along the circumference of the inner sheath 5, the filling strips 1 are evenly distributed inside the inner sheath 5; The second arc segment 16 and the inner wall of the inner sheath 5 are arranged opposite to each other; The filling strip 1 is filled and arranged between the conductor 2 and the inner wall of the inner sheath 5; The filling strip 1 and part of the inner wall of the inner sheath 5 together form a space for placing the temperature measuring optical cable 3; The outer side surface of the conductor 2 is in close contact with the first arc segment 15; The outer sheath 7 is sheathed on the outer side of the inner sheath 5 .

[0022] Specifically, the conductor 2 is a copper conductor 2, and the outside of the conductor 2 is wrapped with an inner shielding layer, a middle insulating layer and an outer shielding layer in sequence from the inside to the outside to form an insulated wire core, and a layer of copper tape is wrapped around the outer periphery of the insulated wire core as a metal shielding layer, thereby improving the insulation performance of the conductor 2 while also improving the anti-interference ability during operation; the filling strip 1 can completely fill the gap between the conductor 2 and the inner sheath 5, or it can be partially filled, as long as it can play a supporting role; preferably, the inner shielding layer is formed by extruding a semi-conductive polyolefin mixture, and the average thickness of the inner shielding layer is 0.8mm; the middle insulating layer is formed by extruding a cross-linked polyethylene material; the middle insulating layer is formed by extruding a cross-linked polyethylene material; The insulation eccentricity of the insulating layer is less than 6%, and the nominal thickness of the middle insulating layer is 4.5mm; the outer shielding layer is formed by extrusion of a semi-conductive polyolefin mixture, and the average thickness of the outer shielding layer is 0.8mm; the conductor 2 shielding, insulation, and insulation shielding adopt a three-layer co-extrusion dry cross-linking process technology; the insulation adopts ultra-clean water-tree-resistant XLPE insulation material, and the residual moisture content in the insulation does not exceed 500ppm; the average insulation thickness is not less than the nominal value, the surface of the insulating core is flat and smooth, without sharp corners, particles, burns and scratches; the size of the pores in the insulation does not exceed 76 microns, and the number of pores within 50~75 microns does not exceed 1.8 / cubic centimeter. The size of impurities (opaque materials or non-uniform cross-linked polyethylene insulation materials) shall not exceed 127 microns, and the number of particles within the range of 50 to 175 microns shall not exceed 0.9 / cubic centimeter; ultra-smooth shielding materials suitable for ultra-clean water-tree-resistant XLPE insulation shall be used, and the conductor 2 shield shall be evenly coated on the conductor 2, with a smooth surface, no obvious twisted wire convexity, no sharp corners, particles, burns or scratches. The sulfur content of the conductor 2 shield shall not exceed 200ppm, and other ionic impurities shall not exceed 20ppm. The insulation shield shall be evenly coated on the insulation surface, the sulfur content of the insulation shield shall not exceed 1000ppm, and other impurity ions shall not exceed 500ppm; the outer shielding layer shall be shielded with copper tape, the thinnest thickness shall not be less than 0.10mm, the average overlap rate shall not be less than 15%, and the minimum overlap rate shall not be less than 5%.

[0023] From the above description, it can be seen that the design has made specific modifications to the component structure of the power cable and the positional relationship between the various structures, so as to ensure that the cable can transmit power normally while effectively protecting the battery core and temperature measuring optical cable 3 inside the cable, thereby improving the stability of the cable operation.

[0024] Furthermore, the above-mentioned intelligent long-life XLPE insulated power cable also includes a non-woven fabric 4; The non-woven fabric 4 is wrapped around the conductor 2 and the filling strip 1 after being cabled; The second arc segment 16 is in close contact with the nonwoven fabric 4; The inner sheath 5 is extruded onto the outer side of the nonwoven fabric 4 .

[0025] Specifically, after the cable is formed, two layers of white non-woven fabric 4 with a nominal thickness of 0.2mm and a width of 65mm are wrapped, with 50% overlap and tied tightly to ensure the roundness of the cable; the inner sheath 5 adopts 90℃ polyvinyl chloride sheath material with a nominal thickness of 2.1mm, an average thickness of not less than the nominal value, and a thinnest thickness of not less than 85% of the nominal value.

[0026] Furthermore, the above-mentioned intelligent long-life XLPE insulated power cable further includes an armor layer 6; The outer part of the inner sheath 5 is longitudinally welded with an armor layer 6; The outer sheath 7 is sleeved on the outer side of the armor layer 6 .

[0027] Specifically, the armor layer 6 is made of aluminum and is spirally embossed. The aluminum sheath is longitudinally wrapped by argon arc welding. The thickness of the aluminum sheath is 1.8mm, the embossing depth is 4.5mm, and the embossing pitch is 23.6mm. The aluminum sheath is longitudinally wrapped on the inner sheath 5, and the weld is 100% welded, and then spirally embossed to form a corrugated aluminum sheath structure to ensure excellent pressure resistance and improve bending performance. At the same time, a close inspection test is added to ensure that there are no defects such as leaking welds and cold welds in the welding. That is, the longitudinal close inspection test is: the two ends of the aluminum sheath are sealed with special sealing caps with an inflation nozzle, and a pressure gauge is connected to one end. 0.40MPa~0.45MPa of nitrogen is filled in. After the air pressure stabilizes, the pressure is not less than 0.35MPa within 4 hours.

[0028] Furthermore, the above-mentioned intelligent long-life XLPE insulated power cable also includes an asphalt anti-corrosion protective layer; The exterior of the armor layer 6 is coated with an asphalt anti-corrosion protective layer; The outside of the asphalt anti-corrosion protective layer is wrapped with a high-electricity polyethylene sheath and a conductive polyolefin sheath in sequence.

[0029] Specifically, the thickness of the applied asphalt anti-corrosion protection layer is 0.2 mm to 0.4 mm; the high-electricity polyethylene sheath and the conductive polyolefin sheath constitute the outer sheath 7 .

[0030] As can be seen from the above description, the design further optimizes the composition structure of the inner sheath 5 and the outer sheath 7, as well as the connection structure therebetween, thereby not only improving the overall strength of the cable, but also enhancing the anti-water seepage performance of the cable, thereby preventing external moisture from gradually penetrating into the insulation of the cable over time to form water trees, and in an electrical environment, causing the water trees to further form electrical trees and ultimately lead to insulation breakdown.

[0031] Furthermore, the temperature measuring optical cable 3 is formed by twisting optical fibers; The number of optical fibers is at least six.

[0032] Specifically, in order to match the structure of the filling strip 1 of the present invention, the number of optical fibers of the present invention is preferably six, so that it will not affect the normal operation of the cable structure and will not affect the optical cable. It can also avoid the situation where the optical cable is stretched by external force and the attenuation increases, thereby affecting the temperature measurement efficiency.

[0033] From the above description, it can be seen that the design has made specific modifications to the composition structure of the temperature measuring optical cable 3 and the number of cores of the temperature measuring optical cable 3, and as the number of cores increases, spare optical fiber units can be reliably provided to ensure the stability of temperature measurement.

[0034] The filling strip of the present invention can assist the production and manufacturing of power cables.

[0035] Please refer to Figure 1 , Embodiment 1 of the present invention is: A filling strip comprises a first supporting portion 11, a connecting portion 12 and a second supporting portion 13 connected in sequence; the first supporting portion 11 and the second supporting portion 13 are arranged at intervals; the first supporting portion 11 and the second supporting portion 13 are arranged in an axisymmetric manner.

[0036] The first support portion 11 and the second support portion 13 are both provided with a first arc segment 15; the connecting portion 12 is arc-shaped; the first arc segment 15 of the first support portion 11, the connecting portion 12 and the first arc segment 15 of the second support portion 13 constitute a saddle structure; the first support portion 11 and the second support portion 13 are both provided with a second arc segment 16; the second arc segment 16 of the first support portion 11 and the second arc segment 16 of the second support portion 13 are both arranged on the side away from the saddle structure; the center of the second arc segment 16 of the first support portion 11 and the center of the second arc segment 16 of the second support portion 13 coincide with each other; the first support portion 11 and the second support portion 13 also include a connecting segment 17; the first arc segment 15, the second arc segment 16 and the connecting segment 17 constitute a hollow structure; the connection between the first arc segment 15 and the connecting segment 17 is connected to the connecting portion 12.

[0037] Please refer to Figure 2 , Embodiment 2 of the present invention is: The present invention also provides an intelligent long-life XLPE insulated power cable, comprising a conductor 2, a temperature measuring optical cable 3, an inner sheath 5, an outer sheath 7, a non-woven fabric 4, an armor layer 6, an asphalt anti-corrosion protective layer and the filling strips 1 in the three embodiments 1; along the circumference of the inner sheath 5, the filling strips 1 are evenly distributed in the inner sheath 5; the second arc segment 16 and the inner wall of the inner sheath 5 are arranged oppositely; the filling strips 1 are arranged between the conductor 2 and the inner wall of the inner sheath 5; the filling strips 1 and part of the inner wall of the inner sheath 5 enclose a space for placing the temperature measuring optical cable 3; the outer side surface of the conductor 2 Close to the first arc segment 15; the outer sheath 7 is sleeved on the outside of the inner sheath 5; the non-woven fabric 4 is wrapped around the outside of the conductor 2 and the filling strip 1 after cabling; the second arc segment 16 is close to the non-woven fabric 4; the inner sheath 5 is extruded on the outside of the non-woven fabric 4; the outer part of the inner sheath 5 is longitudinally welded with an armor layer 6; the outer part of the armor layer 6 is sleeved with the outer sheath 7; the outer part of the armor layer 6 is coated with an asphalt anti-corrosion protective layer; the outer part of the asphalt anti-corrosion protective layer is wrapped with a high-electricity polyethylene sheath and a conductive polyolefin sheath in sequence; the temperature measuring optical cable 3 is formed by twisting optical fibers; the number of optical fibers is six.

[0038] The working principle of the present invention is: determine the length of the cable to be laid and the specific laying point according to the terrain of the laying site. After the laying work is completed, connect the temperature measuring optical cable 3 in the cable to the corresponding temperature measuring equipment, so as to realize real-time monitoring of the cable working temperature.

[0039] In summary, in order to enable the power cable to have a temperature measurement function, the existing power cables only consider how to embed the temperature measurement module inside the cable during the design and manufacturing process. Therefore, the corresponding filling strips are often directly filled between the temperature measurement module and the battery core to ensure that the temperature measurement module can be stably fixed inside the cable, but whether the temperature measurement module will be damaged by bending of the cable during the laying process, which will ultimately affect the temperature measurement effect; to solve this problem, the present invention arranges the filling strip into a first supporting portion, a connecting portion and a second supporting portion connected in sequence, and the first supporting portion, the connecting portion and the second supporting portion are formed between the first supporting portion, the connecting portion and the second supporting portion. A semi-enclosed storage space is formed, which not only provides structural support for the subsequent placement of the corresponding temperature measuring module inside the filling strip, but also provides a corresponding deformation space for the temperature measuring module, thereby avoiding damage to the temperature measuring module during cable laying. In addition, since the filling strip and the corresponding battery cell need to be used in conjunction with each other, and the battery cell is usually cylindrical, in order to make the filling strip and the battery cell adapt to each other, the part of the filling strip of the present invention that contacts the battery cell is set to a saddle shape, so that the battery cell and the filling strip can fit closely, thereby compressing the volume of the cable and making the internal structure of the cable more compact and stable.

[0040] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A filling strip, characterized in that: It includes a first supporting portion, a connecting portion, and a second supporting portion which are connected in sequence; The first supporting portion and the second supporting portion are arranged at an interval; The first supporting portion and the second supporting portion are arranged in an axisymmetric manner.

2. The filling strip according to claim 1, characterized in that: The first supporting portion and the second supporting portion are both provided with a first arc segment; The connecting portion is arc-shaped; The first arc segment of the first supporting portion, the connecting portion, and the first arc segment of the second supporting portion form a saddle structure.

3. The filling strip according to claim 2, characterized in that: The first supporting portion and the second supporting portion are both provided with a second arc segment; The second arc segment of the first supporting portion and the second arc segment of the second supporting portion are both arranged on a side away from the saddle structure.

4. The filling strip according to claim 3, characterized in that: The center of the second arc segment of the first support portion coincides with the center of the second arc segment of the second support portion.

5. The filling strip according to claim 3, characterized in that: The first support portion and the second support portion further include a connecting section; The first arc segment, the second arc segment and the connecting segment form a hollow structure; The connection point between the first arc segment and the connection segment is connected to the connection portion.

6. An intelligent long-life XLPE insulated power cable, characterized in that: It comprises a conductor, a temperature measuring optical cable, an inner sheath, an outer sheath and at least three filling strips according to any one of claims 1 to 5; the filling strips are evenly distributed in the inner sheath along the circumference of the inner sheath; The second arc segment and the inner wall of the inner sheath are arranged opposite to each other; The filling strip is filled and arranged between the conductor and the inner wall of the inner sheath; The filling strip and part of the inner wall of the inner sheath together form a space for placing the temperature measuring optical cable; The outer side surface of the conductor is in close contact with the first arc segment; The outer portion of the inner sheath is sleeved with an outer sheath.

7. The intelligent long-life XLPE insulated power cable according to claim 6, characterized in that: It also includes nonwoven fabrics; The non-woven fabric is wrapped around the conductor and the filling strip after being cabled; The second arc segment is in close contact with the non-woven fabric; The inner sheath is extruded and wrapped on the outer side of the non-woven fabric.

8. The intelligent long-life XLPE insulated power cable according to claim 7, characterized in that: It also includes an armor layer; The outer part of the inner sheath is longitudinally welded with an armor layer; An outer sheath is sleeved on the outside of the armor layer.

9. The intelligent long-life XLPE insulated power cable according to claim 8, characterized in that: It also includes an asphalt anti-corrosion protective layer; The exterior of the armor layer is coated with an asphalt anti-corrosion protective layer; The exterior of the asphalt anti-corrosion protective layer is wrapped in sequence with a high-electricity polyethylene sheath and a conductive polyolefin sheath.

10. The intelligent long-life XLPE insulated power cable according to claim 6, characterized in that: The temperature measuring optical cable is formed by twisting optical fibers; The number of the optical fibers is at least six.

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