Variable-diameter submarine cable factory joint connection method and ocean power transmission network

Abstract

The invention provides a variable-diameter submarine cable factory joint connection method and an ocean power transmission network. The variable-diameter submarine cable factory joint connection method comprises the following steps: S1, preparing a first submarine cable and a second submarine cable; s2, connecting an electric connecting piece between the two conductors and polishing; s3, coating a conductor shielding layer outside the electric connecting piece; s4, cutting body insulating layers of the first submarine cable and the second submarine cable to enable the body insulating layers to be gradually far away from the electric connecting piece from inside to outside in the extension direction of the submarine cables; s5, coating the periphery of the conductor shielding layer with a recovery insulating layer, and enabling the recovery insulating layer to be embedded and connected between the two cut body insulating layers; and S6, the surfaces of the body insulating layer and the recovery insulating layer are coated with insulating shielding layers, and the variable-diameter submarine cable connection is completed after polishing. According to the invention, high-strength connection is realized, meanwhile, the damage of extrusion processing to the inner screen and the conductor of the submarine cable is thoroughly avoided, and the overall quality of the submarine cable is remarkably improved. In addition, the LED lamp has the advantages of being high in connection strength, long in service life, wide in light use range and the like, and a new thought is provided for energy transmission.

Description

[0001] The present invention relates to the technical field of submarine cables, and in particular to a factory joint connection method for a variable-diameter submarine cable and a marine power transmission network. Background Art

[0002] As an important part of realizing the transformation of my country's energy structure, deep-sea wind power, with its large-scale, large-capacity and high-reliability power transmission technology, is an important carrier for ensuring the security of the energy system. Among them, the high-voltage direct current cross-linked polyethylene (XLPE) submarine cable factory connector, as a "chip-level" key technology for realizing long-distance ocean power transmission, is an indispensable and important part of the development of my country's deep-sea wind power large-scale integrated grid-connected power transmission technology.

[0003] The existing factory joint technology is to inject melted XLPE into the surface of the submarine cable body to be connected through hormone processing of two submarine cables with the same conductor cross-section specifications at the same voltage level, and complete the connection after insulation restoration. Since the material of the body is consistent with that of the restored insulation, the size and mechanical properties of the restored submarine cable joint are similar to those of the body insulation. However, in long-distance marine power transmission networks, due to the transmission capacity requirements of different sections of transmission lines, the submarine cables equipped at both ends of the transmission lines have the same voltage level but different conductor cross-sections. The traditional equal-diameter factory joint structure preparation method can no longer meet the requirements of power transmission projects. Specifically, due to the different cross-sectional diameters of the submarine cables, the conventional extrusion processing method is easy to damage the inner shield and conductor of the submarine cable under uneven force, which seriously affects the quality of the submarine cable after connection. There are also problems with the operation effect and unstable connection strength. Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to overcome the problem that it is difficult to achieve variable diameter submarine cable connection in the prior art, and to provide a variable diameter submarine cable factory joint connection method and an ocean power transmission network.

[0005] In order to solve the above technical problems, the present invention provides a method for connecting a variable diameter submarine cable factory joint, which is used to connect a first submarine cable and a second submarine cable, wherein the first submarine cable and the second submarine cable both include a conductor from the inside to the outside, a body shielding layer and a body insulating layer, wherein the cross-sectional diameter of the first submarine cable is greater than the cross-sectional diameter of the second submarine cable, and the method comprises the following steps: step S1, stripping the pre-treated first submarine cable and the second submarine cable to expose the conductor in the first submarine cable and the conductor in the second submarine cable; step S2, connecting an electrical connector between the conductors of the first submarine cable and the second submarine cable, and polishing the electrical connector so that the cross-sectional diameter of the electrical connector is from the conductor of the first submarine cable to the conductor of the second submarine cable; The conductor of the second submarine cable has a uniform transition; step S3, coating the conductor shielding layer outside the electrical connector, so that the conductor shielding layer is connected to the main body shielding layer of the first submarine cable and the main body shielding layer of the second submarine cable respectively; step S4, cutting the main body insulation layer of the first submarine cable and the second submarine cable, so that the main body insulation layer gradually moves away from the electrical connector from the inside to the outside in the extension direction of the submarine cable to form a reaction force cone; step S5, coating the recovery insulation layer on the periphery of the conductor shielding layer, so that the recovery insulation layer is embedded and connected between the two main body insulation layers after cutting; step S6, coating the insulating shielding layer on the surface of the main body insulation layer and the recovery insulation layer, and completing the reducer submarine cable connection after grinding.

[0006] In one embodiment of the present invention, in step S1, the pretreatment includes heating and straightening the joint ends of the first submarine cable and the second submarine cable, and then stripping the two joint ends to expose the conductor in the first submarine cable and the conductor in the second submarine cable.

[0007] In one embodiment of the present invention, in step S2, the two ends of the electrical connector are respectively connected to the two conductors by layered welding, and the electrical connector is simultaneously polished during the layered welding process so that the cross-sectional diameter of the electrical connector is uniformly transitioned from the conductor of the first submarine cable to the conductor of the second submarine cable.

[0008] In one embodiment of the present invention, in step S2, the electrical connector and the conductor are made of the same base material, and the angle between the surface of the electrical connector and the axis of the first submarine cable or the second submarine cable is 30-60°.

[0009] In one embodiment of the present invention, step S3 specifically comprises: grinding the conductor to be connected and the electrical connector, and then coating the outer surface thereof with a semi-conductive tape, heating the semi-conductive tape at 30°C to 50°C for 10 to 20 minutes and then cooling and shaping the semi-conductive tape, and completing the coating of the conductor shielding layer after grinding.

[0010] In one embodiment of the present invention, in step S4, the angle between the outer surface of the insulation layer of the body and the axial direction of the first submarine cable or the second submarine cable is 30-60°.

[0011] In one embodiment of the present invention, in step S4, the main body insulating layer is cut and then polished to improve the smoothness of its outer surface, and then heat treated at a temperature of 50°C to 80°C, and a reaction force cone is formed after cooling and shaping.

[0012] In one embodiment of the present invention, in step S5, the recovery insulation layer embedded and connected between the two main insulation layers is heat treated for 20h~24h at a temperature of 270~290°C, and then polished after cooling and shaping to adjust the diameter of the variable diameter submarine cable connection, and finally the recovery insulation layer is heated and cured at a temperature of 30~50°C.

[0013] In one embodiment of the present invention, the theoretical calculated value of the diameter of the variable diameter submarine cable connection is calculated through conductor resistivity, electric field strength, temperature correlation, insulation geometry and temperature distribution, and the error between the polished main body insulation layer and the diameter of the variable diameter submarine cable connection is less than 2 mm.

[0014] The present invention also provides an ocean power transmission network, which comprises at least one diameter-reducing submarine cable obtained by connecting the diameter-reducing submarine cable factory joint connection method.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art: The variable diameter submarine cable factory joint connection method and the marine power transmission network described in the present invention use electrical connectors to perform transitional connections between the first submarine cable and the second submarine cable with different diameters, and replace the traditional extrusion process with a coating connection method, thereby achieving a high-strength connection while completely avoiding the damage of the inner shield and conductor of the submarine cable by the extrusion process, thereby significantly improving the overall quality of the submarine cable. In addition, the present application can also achieve uniform transitional connections between submarine cables of different diameters, so that they have higher use strength, longer service life and a wide range of use scenarios. Compared with the current conventional processing technology, the present application also has the advantages of cost saving, precise processing, high sealing, and water vapor prevention, providing new ideas for energy transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0017] Figure 1 It is a processing flow chart of the factory joint connection method of the variable diameter submarine cable in the preferred embodiment of the present invention; Figure 2 is through Figure 1 The schematic diagram of the structure of a reducer submarine cable obtained by the factory joint connection method of the reducer submarine cable is shown.

[0018] Explanation of the reference numerals in the specification: 100, first submarine cable; 110, conductor; 120, main body shielding layer; 130, main body insulating layer; 200, second submarine cable; 300, electrical connector; 400, conductor shielding layer; 500, restoration insulating layer; 600, insulating shielding layer. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0020] See also Figure 1 As shown, this embodiment provides a method for connecting a reducer submarine cable factory joint, which is used to connect a first submarine cable 100 and a second submarine cable 200, wherein the first submarine cable 100 and the second submarine cable 200 both include a conductor 110, a body shielding layer 120 and a body insulating layer 130 from the inside to the outside, wherein the cross-sectional diameter of the first submarine cable 100 is greater than the cross-sectional diameter of the second submarine cable 200, and the conductors 110 in the first submarine cable 100 and the second submarine cable 200 are preferably copper, and the method comprises the following steps: Step S1, stripping the pretreated first submarine cable 100 and the second submarine cable 200 to expose the conductor 110 in the first submarine cable 100 and the conductor 110 in the second submarine cable 200; further, in this embodiment, the pretreatment includes heating and straightening the joint ends of the first submarine cable 100 and the second submarine cable 200, and then stripping the two joint ends to expose the conductor 110 in the first submarine cable 100 and the conductor 110 in the second submarine cable 200.

[0021] Step S2, connecting the electrical connector 300 between the conductors 110 of the first submarine cable 100 and the second submarine cable 200, and grinding the electrical connector 300 so that the cross-sectional diameter of the electrical connector 300 is uniformly transferred from the conductor 110 of the first submarine cable 100 to the conductor 110 of the second submarine cable 200; further, in this embodiment, the two ends of the electrical connector 300 are respectively connected to the two conductors 110 by layered welding, and the electrical connector 300 is simultaneously ground during the layered welding process so that the cross-sectional diameter of the electrical connector 300 is uniformly transferred from the conductor 110 of the first submarine cable 100 to the conductor 110 of the second submarine cable 200, wherein the electrical connector 300 and the conductor 110 are the same base material, both are copper components, and the angle between the surface and the axial direction of the first submarine cable 100 or the second submarine cable 200 is 30°.

[0022] Step S3, coating the conductor shielding layer 400 on the outside of the electrical connector 300, so that the conductor shielding layer 400 is connected to the main body shielding layer 120 of the first submarine cable 100 and the main body shielding layer 120 of the second submarine cable 200 respectively; further, in this embodiment, the conductor 110 to be connected and the electrical connector 300 are polished, and then a semi-conductive tape is coated on the outer surface thereof, and the semi-conductive tape is heated at 30°C for 10 minutes and then cooled to shape, and the coating of the conductor shielding layer 400 is completed after polishing.

[0023] Step S4, cutting the main body insulation layer 130 of the first submarine cable 100 and the second submarine cable 200, so that the main body insulation layer 130 gradually moves away from the electrical connector 300 from the inside to the outside in the extension direction of the submarine cable, so as to form a reaction force cone; further, in this embodiment, the angle between the outer surface of the main body insulation layer 130 and the axial direction of the first submarine cable 100 or the second submarine cable 200 is 30°. Specifically, in this embodiment, the main body insulation layer 130 is cut, then polished to improve the smoothness of its outer surface, and then heat treated at a temperature of 50°C, and a reaction force cone is formed after cooling and shaping. Among them, the reaction force cone is used to better control the distribution of the electric field, thereby improving the reliability and safety of the cable as a whole.

[0024] Step S5, wrapping the recovery insulation layer 500 around the conductor shielding layer 400, so that the recovery insulation layer 500 is embedded and connected between the two body insulation layers 130 after cutting; further, in this embodiment, the recovery insulation layer 500 embedded and connected between the two body insulation layers 130 is heat treated for 20 hours at a temperature of 270°C, and polished after cooling and shaping to adjust the diameter of the variable diameter submarine cable connection, and finally the recovery insulation layer 500 is heated and cured at a temperature of 30°C. The theoretical calculated value of the diameter of the variable diameter submarine cable connection is calculated by the resistivity, electric field strength, temperature correlation, insulation geometry and temperature distribution of the conductor 110, and the error between the polished body insulation layer 130 and the diameter of the variable diameter submarine cable connection is less than 2mm. Specifically, the layered wrapping connection method in this embodiment can avoid water seepage caused by gaps due to different cross-sections of the conductor 110, while making the overall bolting effect of the product stable and uniform, which can not only improve the DC breakdown strength of the variable diameter factory joint, but also improve the overall electrical performance of the factory joint, thereby solving the problem that long-distance power transmission networks cannot be connected and transmitted due to different cross-sections of submarine cable conductors 110.

[0025] Step S6, coating the insulating shielding layer 600 on the surface of the main insulating layer 130 and the recovery insulating layer 500, and completing the connection of the reducer submarine cable after polishing. Embodiment 2

[0026] This embodiment provides another method for connecting a factory joint of a variable diameter submarine cable, which is used to connect a first submarine cable and a second submarine cable whose conductors are aluminum and have different cross-sectional diameters. The main processing process, principle and advantages are the same as those of the first embodiment, and will not be described in detail here. The processing steps of this embodiment are as follows: Step S1, stripping the pre-treated first submarine cable and the second submarine cable to expose the conductor in the first submarine cable and the conductor in the second submarine cable.

[0027] Step S2, connecting an electrical connector between the conductors of the first submarine cable and the second submarine cable, and polishing the electrical connector so that the cross-sectional diameter of the electrical connector is uniformly transitioned from the conductor of the first submarine cable to the conductor of the second submarine cable; the electrical connector in this embodiment and the conductor are made of the same base material, both are aluminum elements, and the angle between the surface of the electrical connector and the axial direction of the first submarine cable or the second submarine cable is 60°.

[0028] Step S3, coating the conductor shielding layer on the outside of the electrical connector, so that the conductor shielding layer is connected to the main body shielding layer of the first submarine cable and the main body shielding layer of the second submarine cable respectively; further, in this embodiment, the semi-conductive tape is heated at 50°C for 20 minutes, cooled and shaped, and the conductor shielding layer is coated after polishing.

[0029] Step S4, cutting the main body insulation layer of the first submarine cable and the second submarine cable, so that the main body insulation layer gradually moves away from the electrical connector from the inside to the outside in the extension direction of the submarine cable, so as to form a reaction force cone; further, in this embodiment, the angle between the outer surface of the main body insulation layer and the axial direction of the first submarine cable or the second submarine cable is 60°. Specifically, in this embodiment, the main body insulation layer is cut, then polished to improve the smoothness of its outer surface, and then heat treated at a temperature of 80°C, and the reaction force cone is formed after cooling and shaping.

[0030] Step S5, wrapping the recovery insulation layer around the conductor shielding layer, so that the recovery insulation layer is embedded and connected between the two main insulation layers after cutting; further, in this embodiment, the recovery insulation layer embedded and connected between the two main insulation layers is heat treated at a temperature of 290°C for 24 hours, and after it is cooled and shaped, it is polished to adjust the diameter of the variable diameter submarine cable connection, and finally the recovery insulation layer is heated and cured at a temperature of 50°C.

[0031] Step S6, coating the insulating shielding layer on the surface of the main insulating layer and the recovery insulating layer, and completing the connection of the variable diameter submarine cable after polishing. Embodiment 3

[0032] This embodiment provides another method for connecting a factory joint of a variable diameter submarine cable, which is used to connect a first submarine cable and a second submarine cable whose conductors are copper and have different cross-sectional diameters. The main processing process, principle and advantages are the same as those of the first embodiment, and will not be described in detail here. The processing steps of this embodiment are as follows: Step S1, stripping the pre-treated first submarine cable and the second submarine cable to expose the conductor in the first submarine cable and the conductor in the second submarine cable.

[0033] Step S2, connecting an electrical connector between the conductors of the first submarine cable and the second submarine cable, and polishing the electrical connector so that the cross-sectional diameter of the electrical connector is uniformly transitioned from the conductor of the first submarine cable to the conductor of the second submarine cable; the electrical connector in this embodiment and the conductor are made of the same base material, both are aluminum components, and the angle between the surface of the electrical connector and the axial direction of the first submarine cable or the second submarine cable is 45°.

[0034] Step S3, covering the electrical connector with a conductor shielding layer, so that the conductor shielding layer is connected to the body shielding layer of the first submarine cable and the body shielding layer of the second submarine cable respectively; Step S4, cutting the main body insulation layer of the first submarine cable and the second submarine cable, so that the main body insulation layer gradually moves away from the electrical connector from the inside to the outside in the extension direction of the submarine cable, so as to form a reaction force cone; further, in this embodiment, the angle between the outer surface of the main body insulation layer and the axial direction of the first submarine cable or the second submarine cable is 45°. Specifically, in this embodiment, the main body insulation layer is cut and then polished to improve the smoothness of its outer surface.

[0035] Step S5, covering the outer periphery of the conductor shielding layer with a recovery insulating layer, so that the recovery insulating layer is embedded and connected between the two body insulating layers after cutting.

[0036] Step S6, coating the insulating shielding layer on the surface of the main insulating layer and the recovery insulating layer, and completing the connection of the variable diameter submarine cable after polishing. Embodiment 4

[0037] This embodiment provides a marine power transmission network, which includes at least one reducer submarine cable obtained by connecting the reducer submarine cable factory joint connection method described in the first embodiment.

[0038] In summary, the variable diameter submarine cable factory joint connection method and the marine power transmission network described in the present invention use electrical connectors to perform transitional connections between the first submarine cable and the second submarine cable with different diameters, and the coating connection method replaces the traditional extrusion process, thereby achieving high-strength connection while completely avoiding the damage of the inner shield and conductor of the submarine cable by the extrusion process, thereby significantly improving the overall quality of the submarine cable. In addition, the present application can also achieve uniform transitional connections between submarine cables of different diameters, so that they have higher use strength, longer service life and a wide range of use scenarios. Compared with the current conventional processing technology, the present application also has the advantages of cost saving, precise processing, high sealing, and water vapor prevention, providing new ideas for energy transmission.

[0039] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for connecting a variable diameter submarine cable factory joint, characterized in that: The method is used to connect a first submarine cable and a second submarine cable, wherein the first submarine cable and the second submarine cable both include an inner conductor, a body shielding layer and a body insulating layer, wherein the cross-sectional diameter of the first submarine cable is greater than the cross-sectional diameter of the second submarine cable, and comprises the following steps: Step S1, stripping the pre-treated first submarine cable and the second submarine cable to expose the conductor in the first submarine cable and the conductor in the second submarine cable; Step S2, connecting an electrical connector between the conductors of the first submarine cable and the second submarine cable, and polishing the electrical connector so that the cross-sectional diameter of the electrical connector is uniformly transitioned from the conductor of the first submarine cable to the conductor of the second submarine cable; Step S3, covering the electrical connector with a conductor shielding layer, so that the conductor shielding layer is connected to the body shielding layer of the first submarine cable and the body shielding layer of the second submarine cable respectively; Step S4, cutting the main body insulation layers of the first submarine cable and the second submarine cable so that the main body insulation layers gradually move away from the electrical connector from the inside to the outside in the extension direction of the submarine cable to form a reaction force cone; Step S5, covering the outer periphery of the conductor shielding layer with a recovery insulating layer, so that the recovery insulating layer is embedded and connected between the two body insulating layers after cutting; Step S6, coating the insulating shielding layer on the surface of the main insulating layer and the recovery insulating layer, and completing the connection of the variable diameter submarine cable after polishing.

2. The method for connecting a variable diameter submarine cable factory joint according to claim 1, characterized in that: In step S1, the pretreatment includes heating and straightening the joint ends of the first submarine cable and the second submarine cable, and then stripping the two joint ends to expose the conductor in the first submarine cable and the conductor in the second submarine cable.

3. The method for connecting a variable diameter submarine cable factory joint according to claim 1, characterized in that: In step S2, two ends of the electrical connector are connected to the two conductors respectively by layered welding, and the electrical connector is polished during the layered welding process so that the cross-sectional diameter of the electrical connector is uniformly transitioned from the conductor of the first submarine cable to the conductor of the second submarine cable.

4. The method for connecting a variable diameter submarine cable factory joint according to claim 3, characterized in that: In step S2, the electrical connector and the conductor are made of the same base material, and the angle between the surface of the electrical connector and the axis of the first submarine cable or the second submarine cable is 30-60 degrees.

5. The method for connecting a variable diameter submarine cable factory joint according to claim 1, characterized in that: Step S3 specifically comprises: grinding the conductor to be connected and the electrical connector, and then coating the outer surface with a semi-conductive tape, heating the semi-conductive tape at 30°C to 50°C for 10 to 20 minutes, cooling and shaping the semi-conductive tape, and completing the coating of the conductor shielding layer after grinding.

6. The method for connecting a variable diameter submarine cable factory joint according to claim 1, characterized in that: In step S4, the angle between the outer surface of the insulation layer of the body and the axial direction of the first submarine cable or the second submarine cable is 30-60°.

7. The method for connecting a variable diameter submarine cable factory joint according to claim 1, characterized in that: In step S4, the main body insulating layer is cut and then polished to improve the smoothness of its outer surface. Next, it is heat treated at a temperature of 50° C. to 80° C. and cooled to form a reaction force cone.

8. The method for connecting a variable diameter submarine cable factory joint according to claim 1, characterized in that: In step S5, the recovery insulation layer embedded and connected between the two main insulation layers is heat treated at a temperature of 270-290°C for 20h-24h, and is polished after being cooled and shaped to adjust the diameter of the variable-diameter submarine cable connection. Finally, the recovery insulation layer is heated and cured at a temperature of 30-50°C.

9. The method for connecting a variable diameter submarine cable factory joint according to claim 8, characterized in that: The theoretical calculated value of the diameter of the variable diameter submarine cable connection is calculated through conductor resistivity, electric field strength, temperature correlation, insulation geometry and temperature distribution. The error between the polished main body insulation layer and the diameter of the variable diameter submarine cable connection is less than 2 mm.

10. A marine power transmission network, characterized in that: It comprises at least one reducer submarine cable obtained by connecting through the reducer submarine cable factory joint connection method according to any one of claims 1 to 9.

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