Intelligent carrier cable with stress monitoring and early warning functions and application

Abstract

The invention relates to the technical field of catenary monitoring, in particular to an intelligent carrier cable with a stress monitoring and early warning function and application, the carrier cable adopts a single-core multi-layer copper alloy stranded wire, two tension strain sensing optical units are arranged in a gap of the stranded wire, and the tension strain sensing optical units are arranged in the gap of the stranded wire. The tension strain sensing optical unit comprises a grating fiber, a coating and a double-layer metal armor. A quasi-distributed optical fiber sensing technology is adopted, and tension strain sensing optical units (optical fibers with gratings) are arranged in gaps of an existing carrier cable, so that changes, caused by tension, temperature, wind vibration and mechanical loads, of the carrier cable are sensed in real time. And meanwhile, the copper alloy stranded wires are stranded layer by layer through a concentric layer stranding method, and the optical fibers subjected to insulation reinforcement are fixed in gaps of the stranded wires, so that dual protection of the optical fibers is realized, and mechanical damage and resistance faults of the carrier cable are eliminated. And long-term stability and reliability of the intelligent carrier cable and smooth operation of a railway contact network system are ensured.

Description

Technical Field

[0001] This invention relates to the field of overhead contact line monitoring technology, specifically to an intelligent catenary cable with stress monitoring and early warning functions and its application. Background Technology

[0002] In electrified railways, electrical energy is transmitted through the overhead contact system. The catenary, as a crucial component, serves the dual function of suspending the contact wire and transmitting electrical energy. The contact network is constantly exposed to the complex and ever-changing outdoor environment, including extreme conditions such as high temperatures, snow cover, and strong winds. High-speed train operation significantly impacts the tension stability of the catenary. Furthermore, with the rapid expansion of modern high-speed railway networks, maintenance pressures have increased significantly. Traditional manual inspections and periodic maintenance are insufficient to understand the real-time dynamic load on the catenary. Anomalies leading to wire breaks can cause train stoppages or even derailments. Due to the limitations of safety engineering and traditional methods, real-time monitoring and early warning technologies for catenaries have become a hot research topic. One approach combines fiber optic sensing technology with intelligent contact network systems, further integrating modern AI algorithms and big data models to drive anomaly warning and real-time monitoring functions.

[0003] During the production process of the catenary cable of the overhead contact system, it should be confirmed whether it meets the process control requirements or national standards according to the previous process flow. Based on relevant testing requirements, it should be confirmed whether it meets its electromechanical performance requirements. Furthermore, it should be checked whether the signals of the catenary cable with optical fiber can be transmitted normally, transmitting the wavelength reflected by the grating to the demodulation equipment to form a sensor network, thus enabling remote monitoring.

[0004] CN202510157780.9 discloses an online monitoring and early warning system for the tension of railway catenary cables. This system includes a tension acquisition device, a data center, and a monitoring terminal. The tension acquisition device comprises a pressure-short-range tension sensor, a microprocessor module, a power supply module, and a housing. Installed on the catenary cables, the tension acquisition device directly acquires the tension value and sends fault diagnosis results to maintenance personnel. By using a high-power pressure-short-range tension sensor for hardware control, periodic tension value acquisition is achieved, reducing the amount of wireless data transmission and significantly lowering the system power consumption. This device is simple in structure, lightweight, and can directly measure the tension value of the catenary cables. It solves the problems of unchanged installation methods, inability to diagnose catenary tension compensation device jamming faults, and poor power supply reliability in existing technologies. It has strong engineering application value, effectively improving railway transportation safety and reducing reliance on manual inspection. One detection method involves periodically collecting changes in the tension value at the end of the catenary cable for fault diagnosis. While this method can reduce workload and improve railway transportation safety, it only displays the overall tension change of a single anchor section of the catenary cable and cannot accurately identify the fault location or type. Furthermore, it cannot provide real-time monitoring and early warning of tension changes caused by faults in the entire railway catenary cable network. It also lacks descriptions of protective measures for testing in extreme or special environments.

[0005] CN215850852 discloses a precision-conducting multi-core optical fiber composite catenary, comprising, from the inside out, multi-core optical fibers, a stainless steel sheath, an intermediate layer of stranded wire, and an outer layer of stranded wire. The surface of the multi-core optical fiber is coated with an insulating layer. The stainless steel sheath is formed by welding a stainless steel plate. The intermediate layer of stranded wire has six copper alloy wires, and the outer layer of stranded wire has twelve copper alloy wires. By coating the multi-core optical fiber with stainless steel, the strength of the fiber is improved. The coated multi-core optical fiber has two layers of copper stranded wire, solving the problem of easy fiber breakage under high-intensity mechanical forces in current optical fiber catenary systems. This prevents damage to the optical fiber from the surrounding environment, enabling real-time monitoring, evaluation, and alarm of the catenary system. It can significantly improve the operation and maintenance quality of the contact network system. Even if individual optical fibers break, it will not affect the signal transmission of the entire multi-core optical fiber. However, this catenary is made of sheathed multi-core optical fiber and copper alloy stranded wire. The multi-core optical fiber replaces the central copper alloy metal core of the catenary. Compared with the catenary of electrified railway catenary, this type of catenary changes the structure of the standard catenary, reducing its load-bearing capacity and current-carrying capacity, thus lowering its electromechanical performance for the same specifications. The structural changes and reduced electromechanical performance do not meet the requirements of standard TB / T3111-2017 "Copper and Copper Alloy Stranded Wire for Electrified Railways," and are therefore considered non-standard products. For catenary engineering, this non-standard product poses certain quality and safety risks, making it difficult to quickly determine whether the tension is abnormal and to rapidly locate the fault in the catenary. Summary of the Invention

[0006] To address the problems in existing technologies, this invention provides an intelligent catenary with stress monitoring and early warning functions and its application, which solves the limitations of traditional monitoring methods in electrified railways. It is mainly used to monitor the stress, deformation and other states of the catenary, and to provide real-time prediction and alarm when abnormal locations such as tension, vibration, and wire breakage occur. This can effectively improve the operational safety of high-speed railways and reduce the manual labor intensity and maintenance costs in operation and maintenance.

[0007] This invention is achieved through the following technical solution: A smart catenary with stress monitoring and early warning function is disclosed. The catenary adopts a single-core multi-layer copper alloy stranded wire, and a tension strain sensing optical unit is set in the gap of the stranded wire. The tension strain sensing optical unit includes a grating optical fiber, a coating and a double-layer metal armor.

[0008] Preferably, the grating fiber is a single-mode tight-buffered fiber, the cladding is made of silicon dioxide, the coating is made of Teflon insulating material, and the metal armor is made of SUS 204 stainless steel tape.

[0009] Preferably, the diameter of the single-mode tight-buffered optical fiber is 0.125±0.05mm; the thickness of the coating is 0.125±0.05mm; the thickness of the metal armor is 0.12mm; and the diameter of the tension strain sensing optical unit is 0.615±0.1mm.

[0010] Preferably, the tension strain sensing optical unit is provided with at least two.

[0011] Preferably, the catenary has a metal wire as the center line, and several layers of metal wires are twisted around it according to the twisting pitch and twisting direction. The twisting directions of adjacent layers are opposite, and the outermost twisting direction is to the right.

[0012] Preferably, when the specification of the catenary is 1×19, three layers are set in total, which are referred to as the central layer, the second outermost layer and the outermost layer in sequence; the central layer is provided with a metal wire, the second outermost layer is made of six metal wires twisted together, and the outermost layer is made of twelve metal wires twisted together, with two tension strain sensing optical units located between the second outermost layer and the outermost layer.

[0013] Preferably, when the specification of the catenary is 1×37, a total of four layers are set, which are referred to as the central layer, inner layer, second outer layer and outermost layer in sequence; the central layer is provided with a metal wire, the inner layer is made of six metal wires twisted together, the second outer layer is made of twelve metal wires twisted together, and the outermost layer is made of eighteen metal wires twisted together, and two tension strain sensing optical units are located between the second outer layer and the outermost layer.

[0014] Preferably, the tension strain sensing optical unit is synchronously wrapped according to the twisting pitch of the outermost layer.

[0015] Preferably, the tension strain sensing photoelectric unit is located in a trench between two adjacent stranded metal wires in the outermost layer.

[0016] Application of an intelligent catenary cable with stress monitoring and early warning function in the catenary system.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses an intelligent catenary with stress monitoring and early warning functions. It employs quasi-distributed fiber optic sensing technology, embedding tension-strain sensing optical units (optical fibers with gratings) within the existing catenary gaps to sense changes in the catenary caused by tension, temperature, wind vibration, and mechanical loads in real time. Simultaneously, copper alloy strands are stranded layer by layer using a concentric stranding method, and insulated and reinforced optical fibers are fixed within the strand gaps, achieving dual protection for the optical fibers and eliminating mechanical damage and resistance faults in the catenary. This ensures the long-term stability and reliability of the intelligent catenary, guaranteeing the smooth operation of the railway catenary system.

[0018] Optical fibers are stranded and introduced into the existing catenary structure gaps. A quasi-distributed sensor array using fiber optic gratings (FBGs) is formed based on multiple FBGs with different center wavelengths. This array locates changes in the fiber optic cable and analyzes the signals using demodulation equipment. For better embedding in the catenary stranding, the optical fibers must be heat-resistant, adaptable to the project's climatic conditions, and possess good tensile and compressive strength to prevent fiber breakage within the catenary. Under the same catenary outer diameter and structural conditions, two tension strain sensing optical units are embedded in the interlayer gaps between the outer and sub-outer layers of the stranded wire. This type of intelligent catenary fully complies with the relevant technical requirements of the national standard TB / T3111-2017 "Copper and Copper Alloy Stranded Wires for Electrified Railways".

[0019] Furthermore, the tension strain sensing optical unit employs a synergistic encapsulation technology of Teflon coating and stainless steel strip, forming a gradient protection system within the copper alloy stranded wire composite structure. This effectively overcomes the risk of optical unit breakage caused by high-intensity mechanical loads and complex environmental factors, achieving organic integration of the tension strain sensing optical unit and the catenary while ensuring the original structural parameters and mechanical properties of the catenary. This significantly improves the timeliness and accuracy of intelligent early warning systems for tension, wire breakage, and wire breakage anomalies, effectively enhancing the operational safety of high-speed railways and reducing the labor intensity and maintenance costs associated with operation and maintenance. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of a 1×19 catenary cable; Figure 2 This is a cross-sectional view of a 1×37 catenary cable; Figure 3 This is a schematic diagram of the wrapping of the tension strain sensing optical unit; Figure 4 This is a schematic diagram showing the positions of the groove and the tension strain sensing optical unit; Figure 5 Cross-sectional view of the tension strain sensing optical unit; Figure 6 Cross-sectional view of the tension strain sensing optical unit in a 1×19 load-bearing cable; Figure 7 Cross-sectional view of the tension strain sensing optical unit in a 1×37 load-bearing cable.

[0021] In the figure, 1 is the tension strain sensing optical unit; 101 is the grating fiber; 102 is the cladding; 103 is the coating; 104 is the armor; 2 is the central layer; 3 is the second outermost layer; 4 is the outermost layer; 5 is the inner layer; 6 is the gap; 7 is the groove; and 8 is the metal wire. Detailed Implementation

[0022] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0023] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0024] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0025] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0026] This invention discloses an intelligent load-bearing cable with stress monitoring and early warning function, referring to... Figures 1-7 The catenary cable uses a single-core multi-layer copper alloy stranded wire, and at least two tension strain sensing optical units 1 are arranged in the strand gap 6, with one tension strain sensing optical unit 1 serving as a backup. The tension strain sensing optical unit 1 includes a grating optical fiber 101, a coating 103, and a double-layer metal armor 104.

[0027] Optical fibers are mainly classified into single-mode fiber (SMF) and multimode fiber (MMF) according to their propagation type. In the catenary system of electrified railways, the catenary cables are laid over long distances, with an average anchor section of 1.5km and a maximum distance of nearly 3km. The main characteristics of single-mode fiber are small diameter, high speed, low signal attenuation, and high monitoring accuracy. It is mainly suitable for long-distance, high-precision, and high-speed measurement scenarios.

[0028] This invention uses a tight-buffered optical fiber to write a grating to achieve quasi-distributed tension measurement. The surface of the optical fiber is coated with Teflon material, and the outer layer is an aramid fiber non-metallic reinforcing component. This gives the optical fiber good electromechanical properties such as corrosion resistance, high temperature resistance, fatigue resistance, and compressive and tensile strength, effectively preventing the occurrence of optical fiber breakage and signal path loss in the catenary structure.

[0029] In other words, referencing Figure 4The grating fiber 101 is a single-mode tight-buffered fiber, the cladding 102 is made of silicon dioxide, the coating 103 is made of Teflon insulation, and the metal armor 104 is made of SUS 204 stainless steel tape. Specifically, the diameter of the single-mode tight-buffered fiber is 0.125±0.05mm; the thickness of the coating 103 is 0.125±0.05mm; the thickness of the metal armor 104 is 0.12mm; and the diameter of the tension strain sensing optical unit 1 is 0.615±0.1mm.

[0030] The catenary uses a single metal wire 8 as its centerline, with several layers of metal wires 8 twisted around it according to the twisting pitch and direction. The twisting directions of adjacent layers are opposite, with the outermost layer twisting in the right direction. The common catenary models are JT, JTM, JTMM, and JTMH, and the standard is TB / T3111-2017 "Copper and Copper Alloy Stranded Wires for Electrified Railways". A 0.75mm diameter optical fiber is used as the tension strain sensing optical unit 1.

[0031] Without altering the original structure of the catenary, two small-sized tension strain sensing optical units 1 can be introduced and placed within 70mm of the gap between the outermost layer 3 and the outermost layer 6 of the stranded wire. 2 (1×19), 95mm 2 (1×19), 120mm 2 (1×19), 150mm 2 (1×19), 150mm 2 (1×37) Five specifications.

[0032] When the specification of the catenary is 1×19, there are three layers, which are referred to as the central layer 2, the second outermost layer 3 and the outermost layer 4 in sequence. The central layer 2 is provided with a metal wire 8, the second outermost layer 3 is made of six metal wires 8 twisted together, and the outermost layer 4 is made of twelve metal wires 8 twisted together. Two tension strain sensing optical units 1 are located between the gap 6 of the second outermost layer 3 and the outermost layer 4.

[0033] Specifically, for a 70mm 1×19 stranded wire structure 2 95mm 2 120mm 2 150mm 2 The tension strain sensing optical unit 1 is placed in the gap between the outermost layer 3 and the outermost layer 4 of the catenary. (70mm) 2 The diameter of the single wire in the catenary is 2.10 mm, and the gap 6 between the second outermost layer 3 and the outermost layer 4 is 5.90 mm. 2 The maximum diameter of the tension strain sensing optical unit 1 is 0.75 mm, and a tension strain sensing optical unit 1 with a diameter of 0.615 ± 0.1 mm can be completely embedded in this gap 6. (95 mm) 2The diameter of the single wire in the catenary is 2.50 mm, and the gap between the second outer layer 3 and the outer layer 6 is 8.36 mm. 2 It can accommodate a tension strain sensing optical unit with a maximum diameter of 0.82 mm. (1.120 mm) 2 The diameter of the single wire in the catenary is 2.80 mm, and the gap 6 between the second outermost layer 3 and the outermost layer 4 is 10.49 mm. 2 The tension strain sensing optical unit 1 has a maximum diameter of 0.94 mm for the grating optical fiber 101; 150 mm 2 The diameter of the single wire in the catenary is 3.10 mm, and the gap 6 between the second outermost layer 3 and the outermost layer 4 is 12.86 mm. 2 Tension strain sensing optical unit 1 has a maximum diameter of 1.15 mm; with the catenary structure of 1×19 remaining unchanged, as the diameter of the single filament increases, the gap 6 in the second outermost layer 3 and the outermost layer 4 also increases.

[0034] When the specification of the catenary is 1 × 37, there are four layers, which are referred to as the center layer 2, inner layer 5, second outer layer 3 and outermost layer 4 in sequence. The center layer 2 is provided with a metal wire 8, the inner layer 5 is made of six metal wires 8 twisted together, the second outer layer 3 is made of twelve metal wires 8 twisted together, and the outermost layer 4 is made of eighteen metal wires 8 twisted together. Two tension strain sensing optical units 1 are located between the gap 6 of the second outer layer 3 and the outermost layer 4.

[0035] Specifically, for the 1×37 structure of the load-bearing cable, the tension strain sensing optical unit 1 is placed in the gap between the second outermost layer 3 and the outermost layer, 150mm. 2 The diameter of the single wire in the catenary is 2.25 mm, and the gap between the second outermost layer 3 and the outermost layer 6 is approximately 1.34 mm. 2 The tension strain sensing optical unit 1 is a grating optical fiber 101 with a maximum diameter of 0.80 mm.

[0036] The tension strain sensing optical unit 1 is wound synchronously according to the twisting pitch of the outermost layer 3. Specifically, the tension strain sensing optical unit 1 is placed on the concentric winding device of the winding machine. During the layered winding process, the winding pitch of the tension strain sensing optical unit 1 is adjusted according to the twisting pitch of the outermost layer 3, so that the tension strain sensing optical unit 1 enters the gap 6 between the outermost layer 3 and the outer layer as the winding head rotates, and its position is fixed and produced synchronously with the outermost layer 3. The wire release tension of the tension strain sensing optical unit 1 is set to the minimum without affecting the winding effect, keeping the optical fiber loose and elastic, and preventing it from becoming taut. This method can prevent the optical fiber from being squeezed or broken due to factors such as temperature and vibration under the rated working tension of the catenary.

[0037] The tension strain sensing optical unit 1 is located in the groove 7 between two adjacent stranded metal wires 8 in the outermost layer 3. Specifically, in order to ensure that the tension strain sensing optical unit 1 can be continuously and stably wound in the groove 7 of the copper alloy stranded wire, and to deal with the possibility of "slot jumping" displacement that may occur during the entire winding process, which could cause mechanical damage to the optical unit by the outermost metal wire 4, a non-metallic two-half mold is provided when the optical fiber is wound in the groove 7 of the outermost layer 3. The mold aperture is consistent with the diameter of the outermost layer 3, which can effectively limit the "slot jumping" phenomenon of the tension strain sensing optical unit 1.

[0038] This invention also discloses the application of an intelligent catenary cable with stress monitoring and early warning function in the catenary system.

[0039] This invention discloses an intelligent catenary with stress monitoring and early warning function, enabling the production of catenary products with tension warning capabilities without affecting the original catenary product structure and electromechanical performance. During production, two selected tension strain sensing optical units 1 are spirally wound at a pitch of 3 in the groove 7 between the inner layer 5 and the outermost layer 4 stranded wires. The tension strain sensing optical units 1 can be positioned between the copper wires according to a predetermined route, avoiding mechanical damage to the optical fiber during the single-wire twisting process of the outermost layer 4 stranded wires. Simultaneously, the tension strain sensing optical units 1 employ fiber optic gratings (FBGs), serving as quasi-distributed sensors. Based on multiple FBGs with different center wavelengths, a sensor array is formed, locating changes in the optical fiber and analyzing the signals through demodulation equipment. This achieves a combination of the catenary and the tension strain sensing optical units 1, resulting in a product that possesses both the original electromechanical performance attributes of the catenary and intelligent monitoring and early warning functions.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. An intelligent load-bearing cable with stress monitoring and early warning function, characterized in that, The catenary uses a single-core multi-layer copper alloy stranded wire. A tension strain sensing optical unit (1) is set in the gap (6) of the stranded wire. The tension strain sensing optical unit (1) includes a grating fiber (101), a coating (103), and a double-layer metal armor (104).

2. The intelligent load-bearing cable with stress monitoring and early warning function according to claim 1, characterized in that, The grating fiber (101) is a single-mode tight-packed fiber, the cladding (102) is made of silicon dioxide, the coating (103) is made of Teflon insulation material, and the metal armor (104) is made of SUS 204 stainless steel tape.

3. The intelligent load-bearing cable with stress monitoring and early warning function according to claim 2, characterized in that, The diameter of the single-mode tight-buffered fiber is 0.125±0.05mm; the thickness of the coating (103) is 0.125±0.05mm; the thickness of the metal armor (104) is 0.12mm; and the diameter of the tension strain sensing optical unit (1) is 0.615±0.1mm.

4. The intelligent load-bearing cable with stress monitoring and early warning function according to claim 1, characterized in that, The tension strain sensing optical unit (1) is provided with at least two.

5. The intelligent load-bearing cable with stress monitoring and early warning function according to claim 1, characterized in that, The catenary uses a metal wire (8) as the center line, and several layers of metal wire (8) are twisted on its outer side according to the twisting pitch and twisting direction. The twisting directions of adjacent layers are opposite, and the outermost twisting direction is to the right.

6. The intelligent load-bearing cable with stress monitoring and early warning function according to claim 5, characterized in that, When the specification of the catenary is 1×19, there are three layers, which are referred to as the center layer (2), the second outer layer (3) and the outermost layer (4) respectively. The center layer (2) is provided with a metal wire (8), the second outer layer (3) is made of six metal wires (8) twisted together, and the outermost layer (4) is made of twelve metal wires (8) twisted together. Two tension strain sensing optical units (1) are located between the gap (6) between the second outer layer (3) and the outermost layer (4).

7. The intelligent load-bearing cable with stress monitoring and early warning function according to claim 5, characterized in that, When the specification of the catenary is 1 × 37, there are four layers, which are called the center layer (2), inner layer (5), second outer layer (3) and outermost layer (4) in sequence. The center layer (2) is provided with a metal wire (8), the inner layer (5) is made of six metal wires (8) twisted together, the second outer layer (3) is made of twelve metal wires (8) twisted together, and the outermost layer (4) is made of eighteen metal wires (8) twisted together. Two tension strain sensing optical units (1) are located between the gap (6) between the second outer layer (3) and the outermost layer (4).

8. The intelligent load-bearing cable with stress monitoring and early warning function according to claim 6 or 7, characterized in that, The tension strain sensing optical unit (1) is synchronously wrapped according to the twisting pitch of the outermost layer (3).

9. The intelligent load-bearing cable with stress monitoring and early warning function according to claim 6 or 7, characterized in that, The tension strain sensing unit (1) is located in the groove (7) between two adjacent stranded metal wires (8) in the outermost layer (3).

10. The application of an intelligent catenary cable with stress monitoring and early warning function according to any one of claims 1 to 9 in a catenary system.

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