CN112071497A

CN112071497A - Rated voltage 10 kv-35 kv optical fiber composite overhead insulated cable

Info

Publication number: CN112071497A
Application number: CN202011082070.8A
Authority: CN
Inventors: 田庚; 金榕; 伍光磊; 朱兴; 丰茂磊; 孙福林; 程磊
Original assignee: Jiangsu Hengtong Smart Grids Co Ltd
Current assignee: Jiangsu Hengtong Smart Grids Co Ltd
Priority date: 2020-10-12
Filing date: 2020-10-12
Publication date: 2020-12-11

Abstract

The invention relates to a 10-35 kv optical fiber composite overhead insulated cable with rated voltage, which comprises an internal reinforced core, a conductive layer, a conductor shielding layer and a crosslinked polyethylene insulating layer. The inner reinforcing core comprises an optical fiber unit and one or more layers of aluminum-clad steel wire layers stranded with the optical fiber unit. The conductive layer is formed of one or more aluminum wire layers stranded around the periphery of the inner reinforcing core. The crosslinked polyethylene insulating layer and the insulating layer are coaxially arranged and are sequentially sleeved on the periphery of the conducting layer from inside to outside. By adopting the technical scheme for setting, on one hand, the problem that the transmission cable and the communication optical cable are erected respectively in the conventional way is solved, and the work of drawing and setting steel strands, installing cable fittings and the like is not needed in the construction process; on the other hand, through structural design optimization, the optical fiber composite overhead insulated cable has good consistency with the geometric dimension, mechanical property and electrical property of the conventional overhead insulated cable.

Description

Rated voltage 10 kv-35 kv optical fiber composite overhead insulated cable

Technical Field

The invention relates to the technical field of communication optical cable manufacturing, in particular to a 10-35 kv optical fiber composite overhead insulated cable with rated voltage.

Background

With the rapid development of power transmission and distribution technology and information communication technology, power transmission and high-speed information transmission are inevitably merged together. In 2010, a national grid company makes suggestions about accelerating the construction of a strong smart grid, determines basic principles and overall targets of constructing the strong smart grid, and realizes the targets of reliability, safety, economy, high efficiency, environmental friendliness and safe use of the power grid through application of advanced sensing and measuring technologies, advanced equipment technologies, advanced control methods and advanced decision support system technologies on the basis of an integrated high-speed bidirectional communication network.

With the development of FTTX construction, the construction of basic communication lines is in continuous perfection. Optical fiber cables are widely used in various fields of communication and information transmission. In a medium and low voltage distribution network (less than or equal to 35KV), due to various reasons such as product structure characteristics, power grid and communication authority differentiation and the like, optical fiber communication and power transmission cannot be well combined together to play a larger role. In the prior art, the transmission cable and the communication cable are laid independently of each other, thereby greatly increasing the difficulty of construction. In the process of laying the communication optical cable, especially for the rural and mountain areas with less than wide and scattered houses, the communication optical cable is usually laid in the overhead mode in consideration of the aspects of the comprehensive surrounding environment, the construction cost and the like. The existing communication optical cable generally does not have the capability of bearing the action of a large tension value, so that the steel stranded wires need to be parallelly pulled and arranged in actual construction, and cable fittings (such as suspension clamps, strain clamps, fastening clamps and the like) are attached to realize the long-time reliable and stable operation of the cable line, so that the construction complexity is inevitably increased, and the input and expenditure cost is increased. Thus, a skilled person is urgently needed to solve the above problems.

Disclosure of Invention

Therefore, in view of the above-mentioned problems and drawbacks, the present inventor has collected relevant information, evaluated and considered in many ways, and continuously performed experiments and modifications by technicians with many years of research and development experience in this industry, which finally resulted in the appearance of the 10 kv-35 kv optical fiber composite overhead insulated cable with the rated voltage.

In order to solve the technical problem, the invention relates to a 10-35 kv optical fiber composite overhead insulated cable with rated voltage, which comprises an internal reinforced core, a conductive layer, a conductor shielding layer and a crosslinked polyethylene insulating layer. The internal reinforcing core comprises an optical fiber unit and one or more layers of aluminum-clad steel wire layers stranded with the optical fiber unit. The conductive layer is formed of one or more aluminum wire layers stranded around the periphery of the inner reinforcing core. The conductor shielding layer and the crosslinked polyethylene insulating layer are coaxially arranged and are sequentially sleeved on the periphery of the conducting layer along the direction from inside to outside.

As a further improvement of the technical scheme of the invention, along the length extension direction of the optical fiber unit, the optical fiber unit is always enclosed inside the aluminum-clad steel wire layer. The aluminum clad steel wire layer is formed by a plurality of aluminum clad steel wires which are uniformly distributed and twisted around the periphery of the optical fiber unit in the circumferential direction, and the optical fiber unit is used as a central line for twisting.

As another modified design of the above technical solution, the aluminum-clad steel wire layer is composed of a plurality of aluminum-clad steel wires arranged outside the optical fiber unit. Along the length extension direction, the optical fiber unit is always used as a side line to be stranded around the periphery of the frame aluminum-clad steel wire layer.

As a further improvement of the technical scheme of the invention, the aluminum-clad steel wire is preferably 14% IACS aluminum-clad steel wire or 20% IACS aluminum-clad steel wire.

In a further improvement of the present invention, the optical fiber unit includes a multi-core optical fiber and a fiber paste filled therein.

As a further improvement of the technical scheme of the invention, when the number of the aluminum wire layers is 1, the ratio of the twist pitch to the diameter is controlled to be 16-26; when the number of the aluminum wire layers is 2, the twist pitch ratio of the inner aluminum wire layer is controlled to be 16-26, and the twist pitch ratio of the outer aluminum wire layer is controlled to be 14-22.

As a further improvement of the technical scheme of the invention, when the total number of the aluminum wire layers is more than or equal to 2, the twisting directions of the adjacent layers of the aluminum wire layers are opposite, and the numerical values of the twisting pitch-diameter ratio are sequentially reduced along the direction from inside to outside.

As a further improvement of the technical scheme of the invention, the stranding pitch diameter ratio of the outermost aluminum wire layer is controlled to be 10-16, and the stranding pitch diameter ratio of the innermost aluminum wire layer is controlled to be 10-12.

As a further improvement of the technical scheme of the invention, the outermost aluminum wire layer is preferably stranded by adopting a compact structure.

As a further improvement of the technical scheme of the invention, the optical fiber composite overhead insulated cable with the rated voltage of 10-35 kv further comprises a semi-conductive shielding layer. The semi-conductive shielding layer is made of a semi-conductive material, is sleeved on the periphery of the cross-linked polyethylene insulating layer and has the same potential as the conducting layer.

By adopting the technical scheme for arrangement, on one hand, the problem that the transmission cable and the communication optical cable are erected respectively in the conventional process is solved, and the work of drawing and arranging steel strands, installing cable fittings and the like is not needed in the construction process, so that the construction efficiency is effectively improved, and the construction cost is reduced; on the other hand, through structural design optimization, the optical fiber composite overhead insulated cable has good consistency with the geometric dimension, mechanical property and electrical property of the conventional overhead insulated cable, and meets the three-phase electrical balance and sag consistency of the power transmission and distribution line, so that the optical fiber composite overhead insulated cable can replace one-phase, multi-phase or all overhead insulated cables in the power transmission and distribution line under the same voltage class.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a first embodiment of a 10-35 kv rated optical fiber composite overhead insulated cable according to the present invention.

FIG. 2 is a schematic structural diagram of a second embodiment of the optical fiber composite overhead insulated cable with a rated voltage of 10 kv-35 kv in the invention.

FIG. 3 is a schematic structural diagram of a third embodiment of the optical fiber composite overhead insulated cable with a rated voltage of 10 kv-35 kv according to the present invention.

1-an internal reinforcing core; 11-an optical fiber unit; 111-an optical fiber; 112-fiber paste; 12-an aluminum clad steel wire layer; 121-aluminum clad steel wire; 2-a conductive layer; 21-an aluminum wire layer; 3-a conductor shield layer; 4-crosslinked polyethylene insulation layer; 5-semiconductive shield layer.

Detailed Description

The present invention will be described in further detail with reference to specific examples, and fig. 1 shows a schematic structural view of a first embodiment of a 10kv to 35kv optical fiber composite overhead insulated cable of rated voltage in the present invention, which is mainly composed of an inner core 1, a conductive layer 2, a conductor shield layer 3, a crosslinked polyethylene insulation layer 4, and the like. The internal reinforced core 1 includes an optical fiber unit 11 and an aluminum-clad steel wire layer 12 twisted with the optical fiber unit 11. Along its length extension, the optical fiber unit 11 is always enclosed inside the aluminum-clad steel wire layer 12. The aluminum-clad steel wire layer 12 is formed by a plurality of aluminum-clad steel wires 121 uniformly and circumferentially twisted around the periphery of the optical fiber unit 11, and is twisted with the optical fiber unit 11 as a twisting center line. The conductive layer 2 is formed of an aluminum wire layer 21 twisted around the periphery of the inner core 1. The conductor shielding layer 3 and the cross-linked polyethylene insulating layer 4 are coaxially arranged and sequentially sleeved on the periphery of the conductive layer 2 from inside to outside. By adopting the technical scheme for setting, on one hand, the problem that the power transmission cable and the communication optical cable are separately and independently erected in the conventional process is effectively solved, so that the formed cable has the capacities of transmitting signals and transmitting current, and the construction difficulty is reduced; on the other hand, the aluminum-clad steel wire 121 is a bimetallic wire in which aluminum is continuously and uniformly coated on a steel core, and has the advantages of good electrical conductivity, corrosion resistance, good high-frequency transmission performance, high strength of steel, and the like. In view of this, the addition of the aluminum-clad steel wire layer 12 can effectively improve the tensile strength of the insulated cable, so that the work of drawing steel strands, installing cable fittings and the like is not needed in the construction process, the construction efficiency is effectively improved, and the construction cost is reduced; on the other hand, through structural design optimization, the optical fiber composite overhead insulated cable has good consistency with the geometric dimension, mechanical property and electrical property of the conventional overhead insulated cable, and meets the three-phase electrical balance and sag consistency of the power transmission and distribution line, so that the optical fiber composite overhead insulated cable can replace one-phase, multi-phase or all overhead insulated cables in the power transmission and distribution line under the same voltage class.

It is known that the lightning resistance of an insulated cable is mainly determined by the diameter of the steel member in aluminum-clad steel wire 121, and if the diameter of the strands is the same, the higher the conductivity, the smaller the diameter of the steel member, resulting in an increase in the short-circuit current capacity and a decrease in the strength and lightning resistance. Therefore, on the premise of comprehensively balancing parameters such as short-circuit current capacity, mechanical properties, lightning strike resistance and the like, the aluminum-clad steel wire 121 is preferably 14% IACS aluminum-clad steel wire or 20% IACS aluminum-clad steel wire, so as to ensure that the molded optical fiber composite overhead insulated cable has good lightning protection performance in the actual use process as much as possible.

The pitch-diameter ratio is directly related to the compactness of the aluminum wire layer 21 after the forming, the weight of the stranded wire and the resistance of the stranded wire. Therefore, considering the forming compactness of the insulated cable and the implementation difficulty of the twisting process, the twisting pitch diameter ratio of the aluminum wire layer 21 is preferably controlled within 16-26.

Furthermore, the aluminum wire layer 21 is preferably stranded by adopting a pressing structure, so that the surface of the aluminum wire layer is smoother, and simultaneously, the aluminum wires formed by the aluminum wire layer 21 are ensured to have smaller gap values, the outer diameter value of the aluminum wire layer 21 is smaller as far as possible on the premise of ensuring the conductive capacity, and the forming outer diameter of the insulated cable is further reduced.

It should be emphasized that, according to the actual forming requirement, the number of the aluminum wire layers 21 may also be set 2 according to the actual situation, that is, the aluminum wire layers include an inner aluminum wire layer and an outer aluminum wire layer. In this case, similar to the above-mentioned twisting process, the twist pitch ratio of the inner aluminum wire layer is also controlled to be 16 to 26, and the twist pitch ratio of the outer aluminum wire layer is controlled to be 14 to 22.

Further, in order to improve the overall bending performance of the insulated cable, improve the tensile strength, and reduce the size of the cable as much as possible, so that the insulated cable has a more round and round shape, the inner aluminum wire layer and the outer aluminum wire layer have opposite twisting directions, and the twisting pitch-diameter ratio value is sequentially reduced along the inner direction to the outer direction. On the premise of reverse stranding, the stranding pitch ratio of the outermost aluminum wire layer is controlled to be 10-16, and the stranding pitch ratio of the innermost aluminum wire layer is controlled to be 10-12.

The optical fiber unit 11 preferably includes a 24-core G652D stainless steel tube optical fiber unit. Therefore, the optical fiber unit 11 has excellent optical fiber extra-length performance, the requirements of the aerial insulated cable on extension and contraction caused by temperature change and line creep extension caused by long-term use are met, and the attenuation change of the optical fiber is increased by less than or equal to 0.05 dB/km. The optical fiber unit 11 also has good water-blocking and hydrogen-absorbing properties, prevents moisture from entering the stainless steel tube and reduces the generation of hydrogen ions, so that the optical fiber unit is prevented from being damaged by hydrogen corrosion.

As a further optimization of the structure of the optical fiber composite overhead insulated cable of 10kv to 35kv of the rated voltage, the optical fiber unit 11 can accommodate a plurality of multi-core optical fibers 111. The optical fiber 111 is used as a communication carrier to realize large-capacity and high-speed information transmission, and simultaneously, the optical fiber 111 is used as a sensing element and a transmission signal medium to realize sensing and measurement of different positions of the optical fiber 111 along a path by utilizing the characteristics of optical fiber Raman scattering, Brillouin scattering and Rayleigh scattering. The distributed optical fiber monitoring technology is utilized to perform real-time online monitoring on the temperature, load, vibration, ice coating and the like of the insulated cable in operation, so that the automatic monitoring, trend analysis and operation and maintenance capabilities of the line are improved. The principle is roughly: by using the characteristics of Raman scattering, Brillouin scattering and Rayleigh scattering of the optical fiber 111, the distributed optical fiber monitoring system takes the optical fiber 111 as a sensing element and a transmission signal medium, detects the changes of temperature, strain, polarization, frequency, wavelength, phase and the like at different positions along the optical fiber by adopting an advanced OTDR technology and an OFDR technology, converts the detected change signals into physical quantity change curves of pressure, strain, bending, temperature, vibration, rotation and the like by a terminal processor, and realizes real-time monitoring and early warning of key technical parameters of a lead such as operation temperature, load, strain, sag, galloping and the like. The automatic sensing detection of the line is realized by using a distributed optical fiber sensing measurement technology and video monitoring, and detection information and video images are transmitted to the terminal in real time through the optical fiber 111, so that real-time and accurate data and information are provided for the running state of the line and the environmental change of the line, comprehensive analysis is provided for the running trend and fault judgment of external lines, and unmanned and intelligent monitoring of the line is realized.

The optical fiber 111 preferably adopts a G652D optical fiber with the diameter of 0.2mm, and compared with the traditional optical fiber with the diameter of 0.25mm, the optical fiber capacity in the stainless steel tube optical unit with the same specification can be improved by 30 percent, so that the total core number of the line optical fiber 111 is greatly improved, and the line communication capacity is improved.

Fig. 2 shows a schematic structural diagram of a second embodiment of the optical fiber composite overhead insulated cable with a rated voltage of 10 kv-35 kv in the present invention, which is different from the first embodiment in that: the aluminum-clad steel wire layer 12 is composed of a plurality of aluminum-clad steel wires 121 arranged outside the optical fiber unit 11. Along its length extension, optical fiber unit 11 always serves as a side line to be stranded around the periphery of the layer of aluminum-clad steel wires 121. Compared with the first embodiment, the second embodiment effectively relaxes the requirement on the relative position of the optical fiber unit 11 before twisting, so that the forming process is simpler, the production cost of the insulated cable is further reduced, however, the risk that the optical fiber unit 11 is pulled is increased to a certain extent, and the method is suitable for occasions with relatively short laying distance.

As described above, the conductive layer 2 is formed by twisting a plurality of wires (aluminum wires), and an air gap is easily formed between the conductive layer and the crosslinked polyethylene insulating layer 4, and the surface of the conductive layer 2 itself is not smooth, which causes electric field concentration. Furthermore, when the cable is bent, cracks are easily formed on the surface of the crosslinked polyethylene insulating layer 4, which are factors causing partial discharge. In view of this, fig. 3 shows a schematic structural diagram of a third embodiment of the optical fiber composite overhead insulated cable with a rated voltage of 10kv to 35kv of the present invention, which is different from the two embodiments in that a semiconductive shielding layer 5 made of a semiconductive material is sleeved on the periphery of the crosslinked polyethylene insulating layer 4. And the potentials of the semiconducting shield 5 and the above-mentioned conductive layer 2 are equal. This effectively prevents the occurrence of partial discharge between the conductive layer 2 and the crosslinked polyethylene insulating layer 4.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The optical fiber composite overhead insulated cable with the rated voltage of 10-35 kv is characterized by comprising an internal reinforcing core, a conductive layer, a conductor shielding layer and a crosslinked polyethylene insulating layer; the internal reinforcing core comprises an optical fiber unit and one or more layers of aluminum-clad steel wire layers stranded with the optical fiber unit; the conducting layer is formed by one or more layers of aluminum wire layers which are stranded around the periphery of the internal reinforced core; the conductor shielding layer and the crosslinked polyethylene insulating layer are coaxially arranged and are sequentially sleeved on the periphery of the conducting layer from inside to outside.

2. The 10-35 kv optical fiber composite overhead insulated cable with rated voltage according to claim 1, characterized in that the optical fiber units are always enclosed inside the aluminum-clad steel wire layer along the length extension direction of the optical fiber units; the aluminum clad steel wire layer is composed of a plurality of aluminum clad steel wires which are uniformly distributed and twisted around the periphery of the optical fiber unit in the circumferential direction, and the optical fiber unit is used as a central line to be twisted.

3. The 10-35 kv optical fiber composite overhead insulated cable of rated voltage according to claim 1, wherein the aluminum-clad steel wire layer is composed of a plurality of aluminum-clad steel wires arranged outside the optical fiber unit; along the length extension direction of the optical fiber unit, the optical fiber unit is always used as a side line to be stranded around the periphery of the aluminum-clad steel wire layer.

4. The 10-35 kv optical fiber composite overhead insulated cable of rated voltage according to any one of claims 2-3, wherein the aluminum-clad steel wire is 14% IACS aluminum-clad steel wire or 20% IACS aluminum-clad steel wire.

5. The 10 kv-35 kv optical fiber composite overhead insulated cable of rated voltage according to claim 4, wherein the optical fiber unit is composed of a multicore optical fiber and a fiber paste filled therein.

6. The 10-35 kv optical fiber composite overhead insulated cable with rated voltage according to claim 4, wherein when the number of the aluminum wire layers is 1, the twist pitch ratio is controlled to be 16-26; when the number of the aluminum wire layers is 2, the twist pitch ratio of the inner aluminum wire layer is controlled to be 16-26, and the twist pitch ratio of the outer aluminum wire layer is controlled to be 14-22.

7. The 10-35 kv optical fiber composite overhead insulated cable with rated voltage according to claim 4, wherein when the total number of layers of the aluminum wire layer is greater than or equal to 2, the twisting directions of adjacent layers of the aluminum wire layer are opposite, and the twisting pitch ratio values are sequentially reduced from inside to outside.

8. The 10-35 kv optical fiber composite overhead insulated cable with rated voltage according to claim 7, wherein the ratio of the twist pitch ratio of the aluminum wire layer at the outermost layer is controlled to be 10-16, and the ratio of the twist pitch ratio of the aluminum wire layer at the innermost layer is controlled to be 10-12.

9. The 10-35 kv optical fiber composite overhead insulated cable with rated voltage according to claim 7, wherein the aluminum wire layer at the outermost layer is stranded by adopting a pressing structure.

10. The 10-35 kv optical fiber composite overhead insulated cable with rated voltage according to claim 4, characterized by further comprising a semi-conductive shielding layer; the semi-conductive shielding layer is made of a semi-conductive material, is sleeved on the periphery of the cross-linked polyethylene insulating layer and has the same potential as the conductive layer.