Triggering optical cable for ultra-high voltage power transmission

Abstract

A plurality of optical units are arranged in an outer sheath, the plurality of optical units comprise a first part and a second part, the first part is located at the central axis position of the outer sheath, and the second part is twisted on the outer side of the first part; the optical unit sequentially comprises an optical unit sheath, a tight sleeve layer and a cladding optical fiber from outside to inside. As the whole integrated large-cladding optical fiber is divided into a plurality of optical units, a plurality of devices can be correspondingly controlled; meanwhile, yarns and a central reinforcing steel rope are cancelled, the first part is used as a central reinforcing piece, and the second part is twisted on the outer side of the first part, so that through a special structural design, on the basis that the yarns and the central reinforcing steel rope are cancelled, the structural strength is basically unchanged, and the purpose of increasing the number of control equipment of the trigger optical cable is achieved.

Description

Technical Field

[0001] The present application relates to the field of ultra-high voltage and flexible direct current power transmission, and in particular to a trigger optical cable for ultra-high voltage power transmission. Background Art

[0002] At present, trigger optical cables often use expensive fluoroplastics as sheaths, which have the problem of releasing thick smoke when burning; and yarns are designed in the middle of the optical cable to increase the mechanical strength of the cable. However, in a complex high-voltage electromagnetic field environment, the environment in which the optical cable is located is not completely insulated, and the irregular shape of the yarn easily induces charge accumulation, causing local gap discharge in the optical cable, thereby causing insulation damage to the optical cable, and even heating and fire, leading to operating accidents. Summary of the invention

[0003] The embodiment of the present application provides a trigger optical cable for ultra-high voltage power transmission to solve the problem in the related art that the yarn of the trigger optical cable in a complex high-voltage electromagnetic field environment causes induced charge accumulation and the optical cable has the risk of insulation damage.

[0004] In a first aspect, a trigger optical cable for ultra-high voltage power transmission is provided, comprising:

[0005] An outer sheath, in which a plurality of optical units are arranged, wherein the plurality of optical units include a first part and a second part, wherein the first part is located at a central axis position of the outer sheath, and the second part is twisted outside the first part;

[0006] Wherein, the optical unit comprises an optical unit sheath, a tight jacket layer and a cladding optical fiber in sequence from the outside to the inside.

[0007] In some embodiments, the number of the light units in the first part is three, and they are tangent to each other in pairs, and the extension direction of the light units in the first part is parallel to the central axis of the outer sheath.

[0008] In some embodiments, the number of optical units in the first part is multiple, and they are configured as follows: one of the optical units is coaxially arranged with the central axis of the outer sheath, and the remaining optical units are twisted outside the optical unit coaxial with the central axis of the outer sheath to form an inner twisted layer;

[0009] The optical units in the second part are twisted on the outside of the inner twisted layer to form an outer twisted layer; the inner wall of the outer sheath is in contact with the outer side of the outer twisted layer.

[0010] In some embodiments, the inner twisted layer and the outer twisted layer are unidirectionally twisted, and the twisting intercept is 750mm-800mm.

[0011] In some embodiments, the fiber screening strength of the cladding optical fiber is ≥200 kpsi, and the transmitted energy is ≥0.5 mW.

[0012] In some embodiments, the cladding optical fiber is a quartz core plastic cladding optical fiber, the core cladding of the quartz core plastic cladding optical fiber is 200 / 230 μm, the cladding material is plastic resin, and there is no coating layer.

[0013] In some embodiments, the cladding optical fiber is a quartz optical fiber, the core cladding of the quartz optical fiber is 50 / 125 μm, 62.5 / 125 μm or 105 / 125 μm, and the coating diameter is 235-255 μm.

[0014] In some embodiments, the tight sleeve layer is made of ethylene-tetrafluoroethylene copolymer, polyamide plastic or thermoplastic polyester elastomer material; the diameter of the tight sleeve layer is 0.4-1.0 mm.

[0015] In some embodiments, the optical unit sheath is made of low-smoke halogen-free or thermoplastic polyurethane rubber material; the outer sheath is made of low-smoke halogen-free or thermoplastic polyurethane rubber material;

[0016] The outer sheath is filled with an electrical insulating resin outside the plurality of light units.

[0017] In some embodiments, the roughness Ra value of the outer surface of the optical unit sheath is 0.1 μm-0.2 μm.

[0018] The beneficial effects of the technical solution provided by this application include:

[0019] The embodiment of the present application provides a trigger optical cable for ultra-high voltage power transmission. Since multiple optical units are arranged in the outer sheath, the multiple optical units include a first part and a second part. The first part is located at the central axis position of the outer sheath, and the second part is twisted outside the first part. The optical unit includes an optical unit sheath, a tight sleeve layer and a cladding optical fiber from the outside to the inside. Since the entire large cladding optical fiber is divided into multiple optical units, multiple devices can be controlled accordingly. At the same time, the yarn and the center reinforcement steel rope are eliminated, and the first part is used as the center reinforcement member, and the second part is twisted outside the first part. Therefore, through a special structural design, on the basis of eliminating the yarn and the center reinforcement steel rope, the structural strength is basically unchanged, so as to achieve the purpose of increasing the number of control devices of the trigger optical cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1A schematic diagram of a first structure of a trigger optical cable for ultra-high voltage power transmission provided in an embodiment of the present application;

[0022] Figure 2 A schematic diagram of a second structure of a trigger optical cable for ultra-high voltage power transmission provided in an embodiment of the present application;

[0023] Figure 3 A schematic diagram of the internal structure of the optical unit provided in an embodiment of the present application.

[0024] In the figure: 1, optical unit; 100, optical unit sheath; 101, tight jacket layer; 102, cladding optical fiber; 2, outer sheath. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] The trigger optical cable used in the field of ultra-high voltage power transmission is used as the signal trigger transmission medium between the valve hall and the control tower. It is a series of energy transmission optical cable products that can transmit higher laser power, has good resistance to optical damage, as well as lower attenuation and higher light transmittance. It is mainly used in power control systems, relying on light energy to control the on and off of the valve tower system. The transmission energy is ≥0.5 milliwatts, and it is an application of non-traditional communication systems to transmit optical signals.

[0027] With the rapid development and independence of UHV DC transmission and flexible DC transmission technology in my country, the signal trigger transmission medium between the valve hall and the control tower has gradually received attention, and all signal triggers have gradually been replaced by optical fibers of different specifications. It is well known that single optical fibers are difficult to use directly, and they are often made into optical cables to protect them. At the same time, structural design needs to be combined with the use scenario to ensure the reliability of the optical fiber and the cost can be accepted by the market when it is applied on a large scale.

[0028] At present, foreign countries adopt a layered twisted branch cable structure and use TPU sheath for optical cable production. This solution has a high cost for optical cables. There is a small probability that the optical fiber will break when the optical cable is bent, and TPU will release a large amount of thick smoke when burning, which will seriously endanger the health of personnel under working conditions. At the same time, the domestic independence requirements cannot converge with international technologies.

[0029] This application is aimed at improving the defects of CN103558671A, a trigger optical cable for ultra-high voltage power transmission, in actual use. The development background is that the use of this trigger optical cable is prone to insulation damage. Our company studied and analyzed its principle and found that the cause is caused by the yarn that increases the mechanical strength of the optical cable.

[0030] The irregular shape of the yarn easily induces charge accumulation, causing local gap discharge in the optical cable, which in turn causes insulation damage to the cable, or even heat and fire, leading to operating accidents.

[0031] Therefore, the yarn needs to be eliminated, but the structural strength will decrease after the elimination. In addition, the number of devices controlled by the trigger optical cable is required to be as large as possible. Therefore, in order to ensure that the structural strength does not decrease when the yarn is eliminated and to increase the number of optical fiber cores, research and design were carried out, and the structure of the trigger optical cable of this application was obtained. Please refer to the following description for details.

[0032] refer to Figure 1 and Figure 3 , an embodiment of the present application provides a trigger optical cable for ultra-high voltage power transmission, which includes:

[0033] An outer sheath 2, in which a plurality of optical units 1 are arranged, wherein the plurality of optical units 1 include a first portion and a second portion, wherein the first portion is located at the central axis of the outer sheath 2, and the second portion is twisted outside the first portion;

[0034] The optical unit 1 includes, from outside to inside, an optical unit sheath 100 , a tight jacket layer 101 and a cladding optical fiber 102 .

[0035] Since the entire large-clad optical fiber is divided into multiple parts, that is, multiple optical units 1 are formed, multiple devices can be controlled accordingly; but the yarn is eliminated at the same time. At this time, in order to achieve the purpose of strengthening the structural strength, it is generally necessary to set up reinforcement members, but adding a central reinforcement steel rope will reduce the number of optical units 1. Therefore, the multiple optical units 1 are divided into a first part and a second part, the first part is located at the central axis position of the outer sheath 2, and the second part is twisted on the outside of the first part; so the first part is used as a central reinforcement member, and then is bound inside it in conjunction with the outer sheath 2.

[0036] Thus, the yarn and the central reinforcing steel rope are eliminated without changing the structural strength, and the number of control devices for triggering the optical cable is increased, while the problem of charge accumulation is solved. Through special structural design, the structural strength is basically unchanged while reducing the structure.

[0037] In addition, it should be understood that since it is the energy of light that is transmitted, the performance requirements for light attenuation are not high. It does not need to be hung when used in a complex high-voltage electromagnetic field environment, and the structural strength does not need to be high. Therefore, the above structural design can guarantee strength to a certain extent.

[0038] In some preferred embodiments, in order to further illustrate the distribution form of multiple light units 1 to enhance the structural strength, the following description is given:

[0039] refer to Figure 1 In the first type, there are three light units 1 in the first part, and they are tangent to each other. The extending direction of the light units 1 in the first part is parallel to the central axis of the outer sheath. The first part and the second part are marked A and B respectively.

[0040] refer to Figure 2 , second, the number of optical units 1 in the first part is multiple, and they are configured as follows: one of the optical units 1 is coaxially arranged with the central axis of the outer sheath, and the remaining optical units 1 are twisted on the outside of the optical unit 1 coaxial with the central axis of the outer sheath to form an inner twisted layer;

[0041] The optical unit 1 in the second part is twisted outside the inner twisted layer to form an outer twisted layer; the inner wall of the outer sheath 2 contacts the outer side of the outer twisted layer. The inner twisted layer is marked D, the optical unit 1 coaxial with the center axis of the outer sheath is marked C, and the outer twisted layer is marked E.

[0042] In the above two forms, a part of the optical unit 1 is used as a central reinforcement member, and both forms can be adopted. Preferably, the first form. There is no fiber paste in the above outer sheath 2 and between the optical units 1.

[0043] In some preferred embodiments, the inner twisted layer and the outer twisted layer are unidirectionally twisted, and the twisting intercept is 750mm-800mm.

[0044] The optical fiber screening strength of the cladding optical fiber 102 is ≥200kpsi, and the transmission energy is ≥0.5mW. The cladding optical fiber 102 is a quartz core plastic cladding optical fiber, the core cladding of the quartz core plastic cladding optical fiber is 200 / 230μm, the cladding material is plastic resin, and there is no coating layer. The cladding optical fiber 102 is a quartz optical fiber, the quartz optical fiber core cladding is 50 / 125μm, 62.5 / 125μm or 105 / 125μm, and the coating diameter is 235-255μm.

[0045] In some preferred embodiments, the tight sleeve layer 101 is made of ethylene-tetrafluoroethylene copolymer, polyamide plastic or thermoplastic polyester elastomer material; the diameter of the tight sleeve layer 101 is 0.4-1.0 mm. Ethylene-tetrafluoroethylene copolymer is preferred, and the ETFE, PA, and TPEE used in the tight sleeve layer 101 have good electrical properties. The tight sleeve layer has no gap and does not blend with the optical fiber coating and cladding. When the 5cm tight cladding is peeled off, the optical fiber does not bend, the optical fiber coating and cladding are intact and not damaged, and the 10cm optical fiber cannot be extracted.

[0046] The optical unit sheath 100 is made of low-smoke halogen-free or thermoplastic polyurethane rubber material; the diameter of the optical unit sheath 100 is generally 2.2 mm, and the thickness varies according to the diameter of the tight sleeve layer 101; the LSZH or TPU used in the optical unit sheath 100 has good electrical properties, the tight sleeve layer is not compatible with the sub-unit sheath, the 5cm sheath layer can be peeled off, and the 30cm sheath cannot be withdrawn.

[0047] The outer sheath 2 is made of low smoke zero halogen or thermoplastic polyurethane rubber material. The thickness of the outer sheath 2 is generally above 1.0mm, and the diameter varies according to the number of cores 4-20, generally in the range of 6-20mm. The LSZH or TPU used in the outer sheath 2 has good electrical performance, and the cable core duty ratio is between 40% and 70%.

[0048] In some preferred embodiments, the roughness Ra value of the outer surface of the optical unit sheath 100 is 0.1 μm-0.2 μm. In order to avoid charge accumulation, the smoothness of the outer surface needs to be ensured.

[0049] The outer sheath 2 is filled with electrical insulating resin located outside the plurality of optical units 1 ; the electrical insulating resin has the function of improving the structural strength and improving the waterproof and anti-penetration properties.

[0050] The above ETFE, PA, TPEE, LSZH and TPU are ethylene-tetrafluoroethylene copolymer, polyamide plastic, thermoplastic polyester elastomer, low-smoke halogen-free material or thermoplastic polyurethane rubber material respectively.

[0051] Through the above description, the purpose of this utility model is to develop a low-cost, flame-retardant, and low-smoking optical cable, while ensuring that the optical cable does not accumulate induced charges. The cladding fiber strength exceeds 200kpsi, which greatly improves the tensile strength of the optical cable and reduces the probability of optical fiber breakage;

[0052] The tight sleeve layer 101 of the utility model can effectively ensure the stripping length of the tight sleeve layer 101, and improve the convenience and reliability when making the optical cable connector. The optical unit 1 of the utility model has no yarn, and the surface is flat and smooth, which can avoid charge accumulation. At the same time, LSZH material is preferentially used, which greatly improves the flame retardant performance of the optical cable.

[0053] The cable core of the present invention does not require a central reinforcing steel rope, which greatly reduces the size of the cable core. The optical cable can be made more compact (the outer diameter of each core is reduced by 1 mm on average), the cost can be lower, and bridge resources can be saved during wiring.

[0054] The sheath of the present invention has a moderate duty cycle, which effectively solves the bending performance of the optical cable. At the same time, LSZH materials are preferably used, and the optical cable is extinguished immediately when away from the fire. When it is in the flame for a long time, the smoke is very low, which avoids harm to the respiratory system of personnel under working conditions. The present invention focuses on solving the above-mentioned problems of flame retardancy, smoke generation, charge accumulation, and high cost.

[0055] The principle of this application: Since the entire large cladding optical fiber is divided into multiple parts, that is, multiple optical units 1 are formed, multiple devices can be controlled accordingly; but the yarn is eliminated at the same time. At this time, in order to achieve the purpose of strengthening the structural strength, it is generally necessary to set up reinforcements, etc., but adding a central reinforcement steel rope will reduce the number of optical units 1, so the multiple optical units 1 are divided into a first part and a second part, the first part is located at the central axis position of the outer sheath 2, and the second part is twisted outside the first part; so that the first part is used as a central reinforcement, and then bound inside it with the outer sheath 2. In this way, the yarn and the central reinforcement steel rope are eliminated without basically changing the structural strength, and the number of control devices for triggering the optical cable is increased, and the problem of charge accumulation is solved at the same time.

[0056] In addition, this trigger optical cable has a simple structure, low overall cost, is flame-retardant, and has low smoke emission, while ensuring that no induced charge accumulation occurs in the optical cable.

[0057] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0058] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0059] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A trigger optical cable for ultra-high voltage power transmission, characterized in that: It includes: An outer sheath (2) having a plurality of optical units (1) arranged therein, wherein the plurality of optical units (1) comprise a first part and a second part, wherein the first part is located at a central axis position of the outer sheath (2), and the second part is twisted outside the first part; The optical unit (1) comprises, from the outside to the inside, an optical unit sheath (100), a tight jacket layer (101) and a cladding optical fiber (102).

2. The trigger optical cable for ultra-high voltage power transmission according to claim 1, characterized in that: The number of the light units (1) in the first part is three, and they are tangent to each other in pairs. The extension direction of the light units (1) in the first part is parallel to the central axis of the outer sheath.

3. The trigger optical cable for ultra-high voltage power transmission according to claim 1, characterized in that: The number of the optical units (1) in the first part is multiple, and the configuration is as follows: one of the optical units (1) is coaxially arranged with the central axis of the outer sheath, and the remaining optical units (1) are twisted outside the optical unit (1) coaxial with the central axis of the outer sheath to form an inner twisted layer; The optical unit (1) in the second part is twisted on the outside of the inner twisted layer to form an outer twisted layer; the inner wall of the outer sheath (2) is in contact with the outside of the outer twisted layer.

4. The trigger optical cable for ultra-high voltage power transmission according to claim 3, characterized in that: The inner twisted layer and the outer twisted layer are both unidirectionally twisted, and the twisting intercept is 750mm-800mm.

5. The trigger optical cable for ultra-high voltage power transmission according to claim 1, characterized in that: The optical fiber screening strength of the cladding optical fiber (102) is ≥200 kpsi, and the transmitted energy is ≥0.5 mW.

6. The trigger optical cable for ultra-high voltage power transmission according to claim 5, characterized in that: The cladding optical fiber (102) is a quartz core plastic cladding optical fiber, the core cladding of the quartz core plastic cladding optical fiber is 200 / 230 μm, the cladding material is plastic resin, and there is no coating layer.

7. The trigger optical cable for ultra-high voltage power transmission according to claim 5, characterized in that: The cladding optical fiber (102) is a quartz optical fiber, the core cladding of the quartz optical fiber is 50 / 125 μm, 62.5 / 125 μm or 105 / 125 μm, and the coating layer diameter is 235-255 μm.

8. The trigger optical cable for ultra-high voltage power transmission according to claim 1, characterized in that: The tight sleeve layer (101) is made of ethylene-tetrafluoroethylene copolymer, polyamide plastic or thermoplastic polyester elastomer material; the diameter of the tight sleeve layer (101) is 0.4-1.0 mm.

9. The trigger optical cable for ultra-high voltage power transmission according to claim 1, characterized in that: The optical unit sheath (100) is made of low-smoke halogen-free or thermoplastic polyurethane rubber material; the outer sheath (2) is made of low-smoke halogen-free or thermoplastic polyurethane rubber material; The outer sheath (2) is filled with an electrical insulating resin located outside the plurality of optical units (1).

10. The trigger optical cable for ultra-high voltage power transmission according to claim 1, characterized in that: The roughness Ra value of the outer surface of the optical unit sheath (100) is 0.1 μm-0.2 μm.

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