Extremely-cold-resistant distortion-resistant intelligent early warning cable for wind turbine generator

Abstract

The invention discloses an extremely-cold-resistant anti-torsion intelligent early warning cable for a wind turbine generator, which comprises an extremely-cold-resistant outer sheath, an anti-torsion layer, an extremely-cold-resistant inner sheath, a cabling wrapping tape and a cable core which are arranged from outside to inside, and is characterized in that the cable core comprises a main conductor unit, an auxiliary conductor unit and a temperature measurement optical unit; and gaps among the main conductor unit, the auxiliary conductor unit and the temperature measurement light unit are filled. According to the invention, the polyester yarn plied yarns are added in the conductor I, so that the tensile and anti-dragging performance of the cable is improved; the saddle-shaped filling is designed, and the high-strength aramid fiber strands are added, so that the tensile property of the cable is enhanced, and the filling between the cable cores is more compact; the anti-torsion layer is designed, so that the anti-torsion performance of the cable is enhanced; a soft ethylene propylene rubber insulating material JH-XJ-30A and a chlorinated polyethylene rubber sheath material JH-XH-31A which are resistant to extremely cold at the temperature of 60 DEG C below zero are designed, so that the cable can be easily laid, mounted and twisted for use in an extremely cold environment; the operation state of the conductor is detected in real time through the temperature measurement light unit, and early warning is timely performed.

Description

Technical Field

[0001] The invention belongs to the technical field of cables, and in particular relates to an extreme cold-resistant and anti-twisting intelligent early warning cable for a wind turbine. Background Art

[0002] my country is rich in wind resources, but most of the wind farms are distributed in grasslands and coastal areas. These places are in open areas with large temperature differences. The temperature in cold areas can reach -55℃~-60℃. If cables are laid and used under such extremely cold conditions, extremely stringent technical requirements are placed on cable materials: excellent cold resistance and torsion resistance. In addition, customs clearance requirements must be met for exports. However, the lowest cold-resistant temperature that current cables can reach is generally -25℃~-40℃, and it is difficult to work normally in extremely cold environments such as -55℃~-60℃. Moreover, there are no torsion resistance test regulations for cables in extremely cold conditions in the existing standards. Usually, it is only possible to refer to the existing standards to repeatedly verify whether the cables meet the torsion test for large-angle yaw. Summary of the invention

[0003] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide an extreme cold resistant and anti-twisting intelligent early warning cable for a wind turbine.

[0004] In order to achieve the above purpose and the above technical effect, the technical solution adopted by the present invention is:

[0005] An extreme cold resistant and twist resistant intelligent early warning cable for a wind turbine generator set comprises an extreme cold resistant outer sheath, a twist resistant layer, an extreme cold resistant inner sheath, a cable wrapping tape and a cable core which are arranged in sequence from the outside to the inside. The cable core comprises a plurality of main conductor units, auxiliary conductor units and temperature measuring light units, and the gaps between the main conductor units, the auxiliary conductor units and the temperature measuring light units are filled.

[0006] Furthermore, the main conductor unit includes a conductor I, a first semi-conductive nylon belt, a conductor shield, an extreme cold-resistant insulation, an insulation shield and a second semi-conductive nylon belt which are sequentially arranged from the inside to the outside.

[0007] Furthermore, the bundle pitch diameter ratio of the conductor I is set to 23 to 25 times, and the multiple twist pitch diameter ratio is set to 8 to 10 times. The conductor I adopts Class 5 annealed soft copper conductor, and a single polyester yarn strand with a tensile strength of not less than 600N is added to the conductor I.

[0008] Furthermore, the formula composition of the extreme cold resistant insulation is shown in Table 1:

[0009] Table 1

[0010]

[0011]

[0012] Furthermore, the filler is a saddle-shaped filler strip, the center of which contains a high-strength aramid strand. Furthermore, the formula composition of the extreme cold resistant outer jacket is shown in Table 2:

[0013] Table 2

[0014]

[0015] Furthermore, the formula composition of the extreme cold resistant inner sheath is shown in Table 3:

[0016] Table 3

[0017]

[0018]

[0019] Furthermore, the guiding body unit includes a conductor II, a third semi-conductive nylon belt and a semi-conductive mixture which are sequentially arranged from the inside to the outside.

[0020] Furthermore, the temperature measuring light unit includes a wrapping tape, a central reinforcing rib and a plurality of optical fiber units arranged therein, the central reinforcing rib is arranged at the central position of the temperature measuring light unit, the plurality of optical fiber units are evenly distributed around the central reinforcing rib, and the gaps between adjacent optical fiber units are filled with filling cotton ropes.

[0021] Furthermore, the cable core includes three main conductor units, two auxiliary conductor units and a temperature measuring light unit.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention discloses an extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine. A single polyester yarn strand with a tensile strength of not less than 600N is added to the conductor I, which can increase the tensile and drag resistance of the cable; a saddle-shaped filling is designed and a high-strength aramid strand is added to the center, which can enhance the tensile resistance of the cable and avoid the cable core from being squeezed and deformed during the inner sheath extrusion process. At the same time, the filling between the cable cores is made tighter, which enhances the impact resistance and extrusion resistance of the cable; an anti-twist layer is designed to enhance the anti-twisting performance of the cable; a -60℃ extremely cold-resistant soft EPDM rubber insulation is designed. The insulation material JH-XJ-30A and the -60℃ extreme cold resistant soft chlorinated polyethylene rubber sheath material JH-XH-31A ensure that the cable can be easily laid, installed and twisted in an extremely cold environment. The temperature measuring optical unit is designed to detect the cable operation status in real time through the temperature measuring optical fiber. Once the conductor heats up and the local temperature is too high, the temperature measuring optical fiber will transmit the signal to the receivers on both sides of the cable to achieve the effect of intelligent early warning, which is beneficial to prolonging the service life of the cable. The overall structure of the cable is special and can be super soft, wear-resistant, oil-resistant, moisture-resistant, and resistant to extreme cold and torsion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 It is a structural schematic diagram of the temperature measuring optical unit of the present invention. DETAILED DESCRIPTION

[0026] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0027] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0028] like Figure 1-2 As shown, an extreme cold resistant and anti-twisting intelligent early warning cable for a wind turbine generator system comprises an extreme cold resistant outer sheath 11, an anti-twisting layer 10, an extreme cold resistant inner sheath 9, a cable wrapping tape 8 and a cable core which are arranged in sequence from the outside to the inside. The cable core comprises a plurality of main conductor units, auxiliary conductor units and temperature measuring light units 15. The gaps between the main conductor units, the auxiliary conductor units and the temperature measuring light units 15 are provided with saddle-shaped fillers 7.

[0029] The main conductor unit includes conductor Ⅰ1, first semi-conductive nylon belt 2, conductor shield 3, extreme cold insulation 4, insulation shield 5 and second semi-conductive nylon belt 6, which are arranged in sequence from the inside to the outside. In order to ensure the softness and tensile strength of the product, conductor Ⅰ1 is specially designed:

[0030] Set the wire bundle diameter ratio to 23-25 ​​times, and the conductor double twist diameter ratio to 8-10 times. The smaller the diameter ratio, the softer the cable.

[0031] Conductor Ⅰ1 adopts Class 5 annealed soft copper conductor. By using thinner conductor monofilament, it is helpful to disperse the stress of the conductor itself when the conductor is bent.

[0032] A single polyester yarn strand with a tensile strength of not less than 600N is added in conductor Ⅰ1 to increase the tensile performance of the cable and ensure that the polyester yarn strand is subjected to force during the left-right torsion process.

[0033] Extreme cold insulation 4 adopts extreme cold resistant special rubber formula JH-XJ-30A, and its formula composition is shown in Table 1.

[0034] Table 1

[0035]

[0036]

[0037] The saddle-shaped filler 7 is a saddle-shaped filler strip extruded from a semi-conductive rubber material, and contains a high-strength aramid strand in the center, which can enhance the tensile strength of the cable. When the ordinary cable core is extruded into the inner sheath, the core is often flattened. This embodiment can support the main conductor unit, the auxiliary conductor unit and the temperature measuring light unit 15 by designing an independent support saddle-shaped filler 7, so as to avoid the cable core from being extruded and deformed during the inner sheath extrusion process. On the one hand, it solves the problem of the cable core being extruded and deformed by high temperature and high pressure, and ensures the stability of the center of gravity of each unit. On the other hand, the filling between the cable cores is more compact, which enhances the impact resistance and extrusion resistance of the cable.

[0038] The formula composition of the extreme cold resistant outer sheath 11 is shown in Table 2:

[0039] Table 2

[0040]

[0041] The formula composition of the extreme cold resistant inner sheath 9 is shown in Table 3:

[0042] Table 3

[0043]

[0044] By adding POE (ethylene-octene copolymer), the low-temperature performance can be enhanced, the low-temperature impact resistance can be improved, the Mooney viscosity of the material can be reduced, the softness can be improved, and the processing performance can be improved. By increasing the proportion of TOTM (trioctyl trimellitate) in an appropriate amount, the glass transition temperature and brittle temperature of the rubber can be reduced, and the low-temperature performance of the material can be improved. At the same time, various additives such as reinforcing agents, antioxidants, and vulcanizers can be used to increase reinforcing agents in the base material to improve the low-temperature tensile strength of the material, increase plasticizers, enhance plastic deformation capacity at low temperatures, reduce the glass transition temperature and brittle temperature of chlorinated polyethylene rubber, and improve the low-temperature performance of the material. By integrating the performance of various raw materials, taking advantage of their strengths and making up for their weaknesses, the manufactured cable has excellent aging resistance, low-temperature resistance and other properties.

[0045] From the perspective of rubber structure, rubbers with no double bonds in the main chain and non-polar groups in the side chain (such as EPDM) have better cold resistance. Rubbers with no double bonds in the main chain and polar groups in the side chain (chlorinated polyethylene CPE) have poor cold resistance. Generally, rubber used at low temperatures requires other properties in addition to low-temperature performance, such as oil resistance and medium resistance. Therefore, simply selecting rubber with good cold resistance often cannot meet the use requirements at the same time. Therefore, this embodiment compounded EPDM and CPE. Ethylene propylene diene monomer (EPDM) rubber is a terpolymer of ethylene, propylene and a small amount of non-conjugated diene, and has excellent heat aging resistance, ozone resistance and low-temperature performance. Chlorinated polyethylene (CPE) is a random product made of polyethylene through a chlorine substitution reaction. Chlorinated polyethylene with a chlorine mass fraction of about 35% is an elastomer. It does not contain double bonds in the molecule and has good weather resistance, heat resistance, ozone resistance, oil resistance and other characteristics. Both rubbers have a main chain saturated structure and have good co-vulcanization. The two are blended and used together to complement each other in terms of performance, so that the cable can achieve oil resistance and flame retardant effects while meeting low-temperature requirements.

[0046] After the extreme cold resistant inner sheath 9 is extruded, a layer of aramid yarn strands needs to be woven on the surface to form a mesh structure as a torsion-resistant layer 10 to enhance the anti-twisting performance of the cable. By weaving a layer of aramid yarn strands, when the cable is wound and bent, the convex surface of the bent cable core is subjected to greater tensile force, and the mesh structure can disperse the bending tensile force, increase the anti-fatigue bending life of the cable, and contribute to the long-term use of the cable.

[0047] The guiding body unit comprises a conductor II 12, a third semiconductive nylon tape 13 and a semiconductive mixture 14 which are sequentially arranged from the inside to the outside.

[0048] The temperature measuring optical unit 15 includes a wrapping tape 16, a central reinforcing rib 17 and several optical fiber units arranged therein. The central reinforcing rib 17 is arranged at the central position of the temperature measuring optical unit 15. The central reinforcing rib 17 is a solid FRP filling strip. As a tensile reinforcement structure, it can ensure that the optical fiber is not subjected to stress during the winding and retracting process of the cable, and enhance the drag resistance of the optical unit. Several optical fiber units are evenly distributed on the periphery of the central reinforcing rib 17, and the gaps between adjacent optical fiber units are filled with filling cotton ropes 18. The optical fiber unit includes a loose tube 19 and several temperature measuring optical fibers 20 arranged therein. The loose tube 19 is made of high temperature resistant materials such as fluoroplastics, and can withstand a high temperature environment of 180°C to 210°C for a time of not less than 1h, meeting the requirements of no deformation and attenuation during the processing of rubber materials. The gaps between the temperature measuring optical fibers 20 are filled with lubricating grease 21, and the temperature measuring optical fibers 20 can slide freely in the loose tube 19.

[0049] During the cable production process, the temperature measuring optical unit 15 is implanted in the gap between two adjacent main conductor units and is in close contact with the surface of the main conductor unit. The temperature measuring optical unit 15 is actively paid out by designing the cabling machine to control the constant tension of the pay-out, and a positioning guide wheel is installed in front of the cabling sizing die to implant the temperature measuring optical unit 15 inside the cable along the gap. This solves the problems of jumper, displacement, misalignment, scratches, twisting, extrusion, and breakage caused by the small outer diameter and softness of the temperature measuring optical unit 15 during the cabling implantation process, thereby avoiding optical fiber breakage or unqualified monitoring transmission performance.

[0050] The intelligent early warning host optimizes the design of the driving circuit and the photoelectric acquisition circuit, improves the high-speed nanosecond pulse driving circuit, eliminates the overshoot and tailing phenomena in high-speed driving, and improves the high-speed weak signal amplification circuit to solve the stability problem of the high-bandwidth transimpedance amplifier. The high-speed ADC is used with a fast-response acquisition circuit design to achieve high-precision acquisition of one sampling point at 0.2 meters, and the positioning accuracy is controlled within 0.5 meters. The temperature curve of the temperature measurement software is optimized using smoothing and wavelet denoising algorithms, and combined with the cable line laying layout, a line configuration data visualization interface is designed, and the platform configuration length, number of segments and temperature color display are supported. It is linked with the information of the intelligent early warning host to accurately monitor the overall operating temperature of the cable and the 3D spatial positioning of the line.

[0051] Intelligent early warning cables are cables with advanced functions developed on the basis of traditional cables. They can monitor their own operating status. For example, they can sense the temperature and humidity of the cable. Once the temperature is too high or the humidity is abnormal, they will send a signal, which helps to find hidden faults in advance and reduce power outages and other accidents caused by cable faults. They can also monitor the mechanical damage of the cable, such as whether it is squeezed or stretched. Intelligent early warning cables are also used for the automated control of power transmission systems, which can realize remote control and data transmission, making the management of power systems more efficient and intelligent.

[0052] Fiber temperature measurement is based on the scattering effect. Raman scattering: Raman scattering occurs when light is transmitted in the optical fiber, generating Stokes light and anti-Stokes light. The intensity ratio of the two is related to the temperature. In the temperature measurement system, the laser generates a light pulse. After scattering, the Raman scattered light carrying temperature information returns to the optical path coupler, and then is filtered by the optical splitter, amplified by the receiver photoelectric conversion, and processed by the data acquisition unit to calculate the temperature. The laser generates a light pulse and injects it into the optical fiber. When the light is transmitted in the optical fiber, Raman scattering occurs, generating Stokes light and anti-Stokes light. Among them, the intensity of Stokes light is less affected by temperature, while the intensity of anti-Stokes light changes significantly with temperature. The intensity ratio of the two has a functional relationship with temperature. By measuring the change in the intensity ratio of the two in the back Raman scattered light, the external temperature change can be monitored. Combined with the optical time domain reflectometry technology, different temperature points can be located according to the transmission rate of light in the optical fiber and the time difference between the incident light and the back Raman scattered light, so as to obtain the temperature distribution and precise positioning along the entire optical fiber.

[0053] The distributed fiber temperature measurement system (DTS) detects the temperature changes at different positions along the fiber based on the temperature effect of optical time domain reflectometry (OTDR) and fiber Raman scattering, thus realizing truly distributed measurement. In the system, the fiber is both a transmission medium and a sensing medium. The temperature field at each point in the space where the fiber is located modulates the intensity of the Raman scattered light in the fiber. The spatial temperature information is collected by the wavelength division multiplexer and the photoelectric detector. After signal processing and system demodulation, the temperature information is extracted from the noise in real time. The measured temperature point is located by using the propagation speed of the light wave in the fiber and the time interval of the backlight echo.

[0054] Connect with a coupler: You can use a fiber coupler to connect the temperature measuring fiber and the sensor. The coupler can distribute the input optical signal to different output ports in a certain proportion, so that the optical signal can be reasonably distributed and transmitted between the temperature measuring fiber and the sensor, thereby realizing the collection and processing of temperature signals.

[0055] When the cable is terminated, a six-finger sleeve is used to lead out the temperature measuring optical unit 15 separately, and it is protected by a yellow wax tube and connected to the coupler. The terminal is a distributed optical fiber temperature measurement system.

[0056] Example 1

[0057] like Figure 1-2 As shown, an extreme cold resistant and anti-twisting intelligent early warning cable for a wind turbine comprises an extreme cold resistant outer sheath 11, an anti-twisting layer 10, an extreme cold resistant inner sheath 9, a cable wrapping tape 8 and a cable core which are arranged in sequence from the outside to the inside. The cable core comprises three main conductor units, two auxiliary conductor units and a temperature measuring light unit 15. The gaps between the main conductor units, the auxiliary conductor units and the temperature measuring light unit 15 are provided with saddle-shaped fillers 7.

[0058] The main conductor unit includes conductor Ⅰ1, first semi-conductive nylon belt 2, conductor shield 3, extreme cold insulation 4, insulation shield 5 and second semi-conductive nylon belt 6, which are arranged in sequence from the inside to the outside. In order to ensure the softness and tensile strength of the product, conductor Ⅰ1 is specially designed:

[0059] The bundle diameter ratio is set to 23 times, and the conductor twist diameter ratio is set to 8 times. The smaller the diameter ratio, the softer the cable.

[0060] Conductor Ⅰ1 adopts Class 5 annealed soft copper conductor. By using thinner conductor monofilament, it is helpful to disperse the stress of the conductor itself when the conductor is bent.

[0061] A single polyester yarn strand with a tensile strength of 800N is added to conductor Ⅰ1 to increase the tensile performance of the cable and ensure that the polyester yarn strand is subjected to force during the left-right torsion process.

[0062] Extreme cold insulation 4 adopts extreme cold resistant special rubber formula JH-XJ-30A, and its formula composition is shown in Table 1.

[0063] Table 1

[0064]

[0065] The saddle-shaped filler 7 is a saddle-shaped filler strip extruded from a semi-conductive rubber material, and contains a high-strength aramid strand in the center, which can enhance the tensile strength of the cable. When the ordinary cable core is extruded into the inner sheath, the core is often flattened. This embodiment can support the main conductor unit, the auxiliary conductor unit and the temperature measuring light unit 15 by designing an independent support saddle-shaped filler 7, so as to avoid the cable core from being extruded and deformed during the inner sheath extrusion process. On the one hand, it solves the problem of the cable core being extruded and deformed by high temperature and high pressure, and ensures the stability of the center of gravity of each unit. On the other hand, the filling between the cable cores is more compact, which enhances the impact resistance and extrusion resistance of the cable.

[0066] The extreme cold resistant outer sheath 11 and the extreme cold resistant inner sheath 9 adopt the extreme cold resistant special rubber formula JH-XH-31A, and the formula composition is shown in Table 2.

[0067] Table 2

[0068]

[0069] By adding POE (ethylene-octene copolymer), the low-temperature performance can be enhanced, the low-temperature impact resistance can be improved, the Mooney viscosity of the material can be reduced, the softness can be improved, and the processing performance can be improved. By increasing the proportion of TOTM (trioctyl trimellitate) in an appropriate amount, the glass transition temperature and brittle temperature of the rubber can be reduced, and the low-temperature performance of the material can be improved. At the same time, various additives such as reinforcing agents, antioxidants, and vulcanizers can be used to increase reinforcing agents in the base material to improve the low-temperature tensile strength of the material, increase plasticizers, enhance plastic deformation capacity at low temperatures, reduce the glass transition temperature and brittle temperature of chlorinated polyethylene rubber, and improve the low-temperature performance of the material. By integrating the performance of various raw materials, taking advantage of their strengths and making up for their weaknesses, the manufactured cable has excellent aging resistance, low-temperature resistance and other properties.

[0070] From the perspective of rubber structure, rubbers with no double bonds in the main chain and non-polar groups in the side chain (such as EPDM) have better cold resistance. Rubbers with no double bonds in the main chain and polar groups in the side chain (chlorinated polyethylene CPE) have poor cold resistance. Generally, rubber used at low temperatures requires other properties in addition to low-temperature performance, such as oil resistance and medium resistance. Therefore, simply selecting rubber with good cold resistance often cannot meet the use requirements at the same time. Therefore, this embodiment compounded EPDM and CPE. Ethylene propylene diene monomer (EPDM) rubber is a terpolymer of ethylene, propylene and a small amount of non-conjugated diene, and has excellent heat aging resistance, ozone resistance and low-temperature performance. Chlorinated polyethylene (CPE) is a random product made of polyethylene through a chlorine substitution reaction. Chlorinated polyethylene with a chlorine mass fraction of about 35% is an elastomer. It does not contain double bonds in the molecule and has good weather resistance, heat resistance, ozone resistance, oil resistance and other characteristics. Both rubbers have a main chain saturated structure and have good co-vulcanization. The two are blended and used together to complement each other in terms of performance, so that the cable can achieve oil resistance and flame retardant effects while meeting low-temperature requirements.

[0071] This embodiment adopts the independently developed -60℃ extreme cold resistant soft EPDM rubber insulation material JH-XJ-30A and -60℃ extreme cold resistant soft chlorinated polyethylene rubber sheath material JH-XH-31A. The material hardness is adjusted to below Shore 65, so that the material has excellent cold resistance and flexibility, thereby ensuring that the cable products can be easily laid, installed and twisted in extremely cold environments.

[0072] In this embodiment, after extruding the extreme cold resistant inner sheath 9, a layer of aramid yarn strands needs to be woven on the surface to form a mesh structure as a torsion resistance layer 10 to enhance the anti-twisting performance of the cable. By weaving a layer of aramid yarn strands, when the cable is wound and bent, the convex surface of the bent cable core is subjected to greater tensile force, and the mesh structure can disperse the bending tensile force, increase the anti-fatigue bending life of the cable, and help the long-term use of the cable.

[0073] The guiding body unit comprises a conductor II 12, a third semi-conductive nylon belt 13 and a semi-conductive mixture 14 which are arranged in sequence from the inside to the outside. The semi-conductive mixture 14 is composed of polyacrylamide resin and conductive carbon black.

[0074] The temperature measuring optical unit 15 includes a wrapping tape 16, a central reinforcing rib 17 and six optical fiber units arranged therein. The central reinforcing rib 17 is arranged at the central position of the temperature measuring optical unit 15. The central reinforcing rib 17 is a solid FRP filling strip. As a tensile reinforcement structure, it can ensure that the optical fiber is not subjected to stress during the winding and retracting process of the cable, and enhance the drag resistance of the optical unit. The six optical fiber units are evenly distributed on the periphery of the central reinforcing rib 17. The gaps between adjacent optical fiber units are filled with filling cotton ropes 18. The optical fiber unit includes a loose tube 19 and a plurality of temperature measuring optical fibers 20 arranged therein. The loose tube 19 is made of high temperature resistant materials such as fluoroplastics, and can withstand a high temperature environment of 180°C to 210°C for a time of not less than 1h, meeting the requirements of no deformation and attenuation during the processing of rubber materials. The gaps between the temperature measuring optical fibers 20 are filled with lubricating grease 21, and the temperature measuring optical fibers 20 can slide freely in the loose tube 19.

[0075] During the cable production process, the temperature measuring optical unit 15 is implanted in the gap between two adjacent main conductor units and is in close contact with the surface of the main conductor unit. The temperature measuring optical unit 15 is actively paid out by designing the cabling machine to control the constant tension of the pay-out, and a positioning guide wheel is installed in front of the cabling sizing die to implant the temperature measuring optical unit 15 inside the cable along the gap. This solves the problems of jumper, displacement, misalignment, scratches, twisting, extrusion, and breakage caused by the small outer diameter and softness of the temperature measuring optical unit 15 during the cabling implantation process, thereby avoiding optical fiber breakage or unqualified monitoring transmission performance.

[0076] The intelligent early warning host optimizes the design of the driving circuit and the photoelectric acquisition circuit, improves the high-speed nanosecond pulse driving circuit, eliminates the overshoot and tailing phenomena in high-speed driving, and improves the high-speed weak signal amplification circuit to solve the stability problem of the high-bandwidth transimpedance amplifier. The high-speed ADC is used with a fast-response acquisition circuit design to achieve high-precision acquisition of one sampling point at 0.2 meters, and the positioning accuracy is controlled within 0.5 meters. The temperature curve of the temperature measurement software is optimized using smoothing and wavelet denoising algorithms, and combined with the cable line laying layout, a line configuration data visualization interface is designed, and the platform configuration length, number of segments and temperature color display are supported. It is linked with the information of the intelligent early warning host to accurately monitor the overall operating temperature of the cable and the 3D spatial positioning of the line.

[0077] Intelligent early warning cables are cables with advanced functions developed on the basis of traditional cables. They can monitor their own operating status. For example, they can sense the temperature and humidity of the cable. Once the temperature is too high or the humidity is abnormal, they will send a signal, which helps to find hidden faults in advance and reduce power outages and other accidents caused by cable faults. They can also monitor the mechanical damage of the cable, such as whether it is squeezed or stretched. Intelligent early warning cables are also used for the automated control of power transmission systems, which can realize remote control and data transmission, making the management of power systems more efficient and intelligent.

[0078] Fiber temperature measurement is based on the scattering effect. Raman scattering: Raman scattering occurs when light is transmitted in the optical fiber, generating Stokes light and anti-Stokes light. The intensity ratio of the two is related to the temperature. In the temperature measurement system, the laser generates a light pulse. After scattering, the Raman scattered light carrying temperature information returns to the optical path coupler, and then is filtered by the optical splitter, amplified by the receiver photoelectric conversion, and processed by the data acquisition unit to calculate the temperature. The laser generates a light pulse and injects it into the optical fiber. When the light is transmitted in the optical fiber, Raman scattering occurs, generating Stokes light and anti-Stokes light. Among them, the intensity of Stokes light is less affected by temperature, while the intensity of anti-Stokes light changes significantly with temperature. The intensity ratio of the two has a functional relationship with temperature. By measuring the change in the intensity ratio of the two in the back Raman scattered light, the external temperature change can be monitored. Combined with the optical time domain reflectometry technology, different temperature points can be located according to the transmission rate of light in the optical fiber and the time difference between the incident light and the back Raman scattered light, so as to obtain the temperature distribution and precise positioning along the entire optical fiber.

[0079] The distributed fiber temperature measurement system (DTS) detects the temperature changes at different positions along the fiber based on the temperature effect of optical time domain reflectometry (OTDR) and fiber Raman scattering, thus realizing truly distributed measurement. In the system, the fiber is both a transmission medium and a sensing medium. The temperature field at each point in the space where the fiber is located modulates the intensity of the Raman scattered light in the fiber. The spatial temperature information is collected by the wavelength division multiplexer and the photoelectric detector. After signal processing and system demodulation, the temperature information is extracted from the noise in real time. The measured temperature point is located by using the propagation speed of the light wave in the fiber and the time interval of the backlight echo.

[0080] Connect with a coupler: You can use a fiber coupler to connect the temperature measuring fiber and the sensor. The coupler can distribute the input optical signal to different output ports in a certain proportion, so that the optical signal can be reasonably distributed and transmitted between the temperature measuring fiber and the sensor, thereby realizing the collection and processing of temperature signals.

[0081] When the cable is terminated, a six-finger sleeve is used to lead out the temperature measuring optical unit 15 separately, and it is protected by a yellow wax tube and connected to the coupler. The terminal is a distributed optical fiber temperature measurement system, model DTS-LC-55 (PRE).

[0082] The cable of this embodiment has excellent low-temperature performance. The elongation at break exceeds 50% under the -60°C test environment, which is better than the 30% requirement of the GB / T2951.14 standard. It can meet the extremely cold survival environment of -55°C to -60°C. At the same time, it passes the -55°C cable extreme cold torsion test and meets the needs of large-angle yaw torsion of wind turbine cables.

[0083] This embodiment does not crack in -40℃ low temperature impact test and bending test, and can maintain flexibility at extremely low temperature, which meets the requirements of using the cable in low temperature or marine climate environment, and is suitable for use in environmental conditions with large temperature difference, salt spray, damp heat, mold, etc. In addition, the insulation material and sheath material are environmentally friendly and can meet the EU ROHS and PAHS polycyclic aromatic hydrocarbon environmental protection requirements.

[0084] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0085] 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 structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine, characterized in that: It includes an extreme cold resistant outer sheath, a torsion-resistant layer, an extreme cold resistant inner sheath, a cabling tape and a cable core which are arranged in sequence from the outside to the inside. The cable core includes a plurality of main conductor units, auxiliary conductor units and temperature measuring light units. The gaps between the main conductor units, the auxiliary conductor units and the temperature measuring light units are filled.

2. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 1 is characterized in that: The main conductor unit comprises a conductor I, a first semi-conductive nylon belt, a conductor shield, an extreme cold-resistant insulation, an insulation shield and a second semi-conductive nylon belt which are sequentially arranged from the inside to the outside.

3. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 2 is characterized in that: The bundle pitch diameter ratio of the conductor I is set to 23 to 25 times, and the multiple twist pitch diameter ratio is set to 8 to 10 times. The conductor I adopts a Class 5 annealed soft copper conductor, and a single polyester yarn strand with a tensile strength of not less than 600N is added to the conductor I.

4. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 2 is characterized in that: The formula composition of the extreme cold resistant insulation is shown in Table 1: Table 1 5. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 1 is characterized in that: The filler is a saddle-shaped filler strip, the center of which contains a high-strength aramid strand.

6. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 1, characterized in that: The formula composition of the extreme cold resistant outer sheath is shown in Table 2: Table 2 7. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 1, characterized in that: The formula composition of the extreme cold resistant inner sheath is shown in Table 3: Table 3 8. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 1, characterized in that: The guiding body unit comprises a conductor II, a third semi-conductive nylon belt and a semi-conductive mixture which are sequentially arranged from the inside to the outside.

9. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 1, characterized in that: The temperature measuring light unit includes a wrapping tape, a central reinforcing rib arranged therein, and a plurality of optical fiber units. The central reinforcing rib is arranged at the central position of the temperature measuring light unit, and the plurality of optical fiber units are evenly distributed around the central reinforcing rib. The gaps between adjacent optical fiber units are filled with filling cotton ropes.

10. The extremely cold-resistant and anti-twisting intelligent early warning cable for a wind turbine according to claim 1, characterized in that: The cable core comprises three main conductor units, two auxiliary conductor units and a temperature measuring light unit.

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