An armored optical cable and an armored optical cable anti-freezing system based on SELV power supply

Abstract

The application belongs to the technical field of optical cable anti-freezing, and relates to an armored optical cable and an armored optical cable anti-freezing system based on SELV power supply. The armored optical cable anti-freezing system comprises an SELV power supply module, an armored optical cable, an electrode interface, a temperature sensor and a temperature control module. The armored optical cable comprises a cable core, a metal armored layer and an outer sheath arranged in sequence from inside to outside. The electrode interface is arranged at both ends of the metal armored layer and connected with the SELV power supply module to form a closed direct current loop, and the metal armored layer generates Joule heat through the closed direct current loop. The temperature sensor monitors the temperature of the armored optical cable. When the temperature is not higher than a preset low temperature threshold, the temperature control module controls the SELV power supply module to supply power. When the temperature is higher than a preset high temperature threshold, the control stops the power supply. The application utilizes the metal armored layer of the optical cable as a heating body, drives the armored layer to generate Joule heat through SELV safe extra-low voltage, and realizes closed-loop temperature control through the temperature control module.

Description

Technical Field

[0001] This application belongs to the field of optical cable antifreeze technology, and more specifically, relates to an armored optical cable and an armored optical cable antifreeze system based on SELV power supply. Background Technology

[0002] Optical fiber cable is a communication cable used to transmit optical signals. Armored optical fiber cables, with their metal armor protective layer, have better resistance to compression and tension, and are widely used in complex scenarios such as low-temperature environments and underground burial.

[0003] In high-latitude, cold regions or low-temperature winter environments, optical fiber cables are prone to embrittlement due to excessively low ambient temperatures. Simultaneously, external moisture can penetrate the cable, freeze, and expand, damaging the cable's protective layer and squeezing the fiber core, ultimately causing communication signal interruptions and affecting the stable operation of the communication network. To address the problem of optical fiber cable freezing damage in low-temperature environments, current common anti-freezing solutions involve wrapping the cable with a thick insulation layer. This method only slows down the rate of low-temperature conduction and cannot fundamentally prevent freezing damage. The additional insulation layer also increases the overall outer diameter of the cable, increasing the difficulty of installation and material costs. Some solutions integrate electric heating structures inside the cable to maintain its temperature through heat generation. However, these heating structures mostly use high-voltage power supplies, typically requiring expensive high-voltage insulation modifications and dedicated high-power de-icing power supplies. Furthermore, they are usually used in high-voltage transmission lines, posing a risk of leakage in long-distance outdoor installations, resulting in low safety and failing to meet the safety requirements of complex environments. Summary of the Invention

[0004] In response to the deficiencies or improvement needs of existing technologies, this application provides an armored optical cable and an armored optical cable antifreeze system based on SELV power supply. It aims to solve the problems of traditional optical cable antifreeze technology relying on high voltage power supply and complex insulation modification, which result in high system cost, complex structure, and difficulty in achieving effective antifreeze in low voltage power supply environments.

[0005] The first aspect of this application provides an armored optical cable, comprising a cable core, a metal armor layer, and an outer sheath arranged sequentially from the inside to the outside; The axial ends of the metal armor layer are used to connect to an external SELV power module through electrode interfaces to form a closed DC circuit; the metal armor layer generates Joule heat through the closed DC circuit to prevent the armored optical cable from freezing.

[0006] As a further preferred embodiment, the metal armor layer includes an aluminum strip armor layer and a steel strip armor layer, with the aluminum strip armor layer located outside the steel strip armor layer.

[0007] As a further preferred embodiment, a heat insulation layer is provided between the aluminum strip armor layer and the steel strip armor layer.

[0008] As a further preferred embodiment, the heat insulation layer is at least one of glass fiber tape, flame-retardant PET tape, and aramid fiber woven mesh layer.

[0009] As a further preferred embodiment, an inner sheath is provided between the heat insulation layer and the steel strip armor layer.

[0010] The second aspect of this application provides a SELV-powered armored optical cable anti-freezing system, which adopts the following technical solution: A SELV-powered armored optical cable anti-freeze system specifically includes: SELV power module; Any of the armored optical cables mentioned in the first aspect above; The electrode interface includes a positive interface and a negative interface, which are respectively located at both ends of the axial direction of the metal armor layer and electrically connected to the metal armor layer; the positive interface is electrically connected to the positive terminal of the SELV power module, and the negative interface is electrically connected to the negative terminal of the SELV power module to form a closed DC circuit; the metal armor layer generates Joule heating through the closed DC circuit. A temperature sensor, used to monitor the temperature of the armored optical cable; A temperature control module is electrically connected to the temperature sensor and the SELV power module. The temperature control module is configured to: control the SELV power module to supply power to the metal armor layer when the temperature detected by the temperature sensor is not higher than a preset low temperature threshold; and control the SELV power module to stop supplying power to the metal armor layer when the temperature detected by the temperature sensor is not lower than a preset high temperature threshold.

[0011] As a further preferred embodiment, the positive terminal of the SELV power module is grounded, and the negative terminal output potential is -48V.

[0012] As a further preferred embodiment, the temperature sensor is a distributed fiber optic temperature measurement system or a Pt100 platinum resistance temperature sensor.

[0013] As a further preferred embodiment, the preset low temperature threshold is between 0℃ and 2℃, and the preset high temperature threshold is between 4℃ and 6℃.

[0014] As a further preferred embodiment, the length of a single segment of the armored optical cable is no more than 500m.

[0015] In summary, compared with the prior art, the technical solutions conceived in this application have the following main technical advantages: 1. This application uses SELV (Extra-Low Voltage) safety (-48V DC power supply) to drive the metal armor layer to heat up, so that this design does not require expensive high-voltage insulation modification of the optical cable. It can directly use the -48V DC power supply of the communication equipment to achieve anti-freeze heating. The total system cost can be significantly reduced compared with the existing high-voltage power supply solution, which significantly improves economy and ease of implementation. It is particularly suitable for short-distance, low-voltage power supply scenarios such as communication base station lead-in lines.

[0016] 2. This application utilizes the optical cable's own metal armor layer as a heating element, eliminating the need for separate heating wires or devices. This simplifies the armored optical cable and reduces manufacturing costs and complexity. Furthermore, the metal armor layer generates heat according to Joule's law when energized, resulting in uniform heating and providing a stable anti-freeze heating effect along the entire length of the optical cable. 3. This application effectively prevents the heat generated by the aluminum tape armor layer from being directly conducted inward by setting a heat insulation layer between the aluminum tape armor layer and the steel tape armor layer, avoiding optical fiber attenuation or damage due to overheating, and ensuring stable and reliable optical transmission performance of the optical cable during the freeze-thaw process. In addition, the heat insulation layer also has flame-retardant properties, improving the fire safety of the optical cable.

[0017] 4. The armored optical cable provided in this application allows for direct connection to an external power source to form a closed loop by setting electrode interfaces at both ends of the metal armor layer, eliminating the need for complex electrical modifications and achieving plug-and-play functionality. This simple structural design facilitates engineering implementation and subsequent maintenance, improving the system's reliability and practicality. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the armored optical cable provided in the embodiments of this application; Figure 2 This is a cross-sectional view of the armored optical cable provided in the embodiments of this application; Figure 3 This is a schematic diagram of the armored optical cable antifreeze system based on SELV power supply provided in the embodiments of this application.

[0019] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. SELV power module; 2. Armored optical cable; 2-1. Cable core; 2-1a. Central reinforcement; 2-1b. Fiber optic unit; 2-2. Metal armor layer; 2-2a. Aluminum tape armor layer; 2-2b. Steel tape armor layer; 2-3. Outer sheath; 2-4. Thermal insulation layer; 2-5. Inner sheath; 3. Positive interface; 4. Negative interface; 5. Temperature sensor; 6. Temperature control module. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.

[0022] like Figure 1 and Figure 2 As shown, this application provides an armored optical cable. The armored optical cable includes a cable core 2-1, a metal armor layer 2-2, and an outer sheath 2-3 arranged sequentially from the inside to the outside; wherein, the two axial ends of the metal armor layer 2-2 are used to connect to an external SELV power module through an electrode interface to form a closed DC circuit; the metal armor layer 2-2 generates Joule heat through the closed DC circuit.

[0023] Furthermore, in some embodiments, the metal armor layer 2-2 serves as a heating element, preferably comprising an aluminum strip armor layer 2-2a and a steel strip armor layer 2-2b, with the aluminum strip armor layer 2-2a located outside the steel strip armor layer 2-2b, and a heat insulation layer 2-4 disposed between the two.

[0024] After adopting the above-mentioned double-layer structure design including aluminum tape armor layer 2-2a and steel tape armor layer 2-2b, the steel tape armor layer 2-2b has high mechanical strength and moderate resistivity, making it suitable as the main heat-generating element. The aluminum tape armor layer 2-2a has a lower density, weighing approximately one-third the weight of the steel tape for the same volume, and its resistivity is lower than that of the steel tape. It can work in conjunction with the steel tape armor layer 2-2b to adjust the overall circuit resistance, adapting to the output power of the SELV power module. This avoids problems such as excessively high resistance causing the heating power to exceed the power supply's capacity limit, or excessively low resistance failing to generate sufficient anti-freezing heat, ensuring that the heating power remains within the reasonable range required by the design. The insulation layer 2-4 isolates the heat conduction between the steel tape armor layer 2-2b and the aluminum tape armor layer 2-2a, preventing excessive heat loss through inward transfer. This allows the armored optical cable to achieve heating and anti-freezing based on the metal armor layer 2-2 through low-voltage power supply, achieving excellent anti-freezing performance with low cost and low structural complexity.

[0025] Furthermore, in some embodiments, the cable core 2-1 includes a central reinforcement 2-1a and a plurality of optical fiber units 2-1b surrounding the central reinforcement 2-1a. The optical fiber unit 2-1b includes a sleeve in which an optical fiber for transmitting optical signals is disposed.

[0026] Furthermore, in some embodiments, the heat insulation layers 2-4 may be made of materials that are resistant to high temperatures and have low thermal conductivity, such as at least one of glass fiber tape, flame-retardant PET tape, and aramid fiber woven mesh.

[0027] For the insulation layer 2-4, when using fiberglass tape, it can effectively block the heat generated by the metal armor layer 2-2 from being directly conducted to the cable core 2-1, protecting the optical fiber from high-temperature damage. When using flame-retardant PET tape, it combines heat insulation and flame-retardant properties, making it suitable for scenarios with high fire safety requirements. When using aramid fiber braided mesh, it provides good tensile strength while providing heat insulation. All of the above insulation materials can be used individually or in combination according to actual needs, ensuring effective heat insulation while improving the overall safety performance of the optical cable.

[0028] Furthermore, in some embodiments, an inner sheath 2-5 is provided between the steel tape armor layer 2-2b and the heat insulation layer 2-4. The inner sheath 2-5 can protect the internal optical fibers and other filling structures (such as fiber grease), ensuring the mechanical stability and sealing of the optical cable in complex environments. The materials of the inner sheath 2-5 and the outer sheath 2-3 can be high-density polyethylene, polyvinyl chloride, etc.

[0029] In general, the armored optical cable comprises, from the inside out, a central reinforcing member 2-1a, an optical fiber unit 2-1b, a steel tape armor layer 2-2b, an inner sheath 2-5, a heat insulation layer 2-4, an aluminum tape armor layer 2-2a, and an outer sheath 2-3. This armored optical cable allows for direct connection to an external SELV power source to form a closed loop via electrode interfaces at both ends of the metal armor layer 2-2, eliminating the need for additional heating devices and enabling plug-and-play functionality.

[0030] like Figure 3 As shown, this application also provides a short-distance armored optical cable anti-freezing system based on SELV power supply. The system includes a SELV power module 1, an armored optical cable 2, electrode interfaces, a temperature sensor 5, and a temperature control module 6. The armored optical cable 2 includes a cable core 2-1, a metal armor layer 2-2, and an outer sheath 2-3 arranged sequentially from the inside out. The electrode interface includes a positive interface 3 and a negative interface 4, which are respectively located at both ends of the axial direction of the metal armor layer 2-2 and electrically connected to it. The positive interface 3 is electrically connected to the positive terminal of the SELV power module 1, and the negative interface 4 is electrically connected to the negative terminal of the SELV power module 1, forming a closed DC circuit. The metal armor layer 2-2 generates Joule heat through this closed DC circuit. The temperature sensor 5 is configured to monitor the temperature of the armored optical cable 2. The temperature control module 6 is electrically connected to the temperature sensor 5 and the SELV power module 1 respectively. When the temperature detected by the temperature sensor 5 is not higher than the preset low temperature threshold, the temperature control module 6 controls the SELV power module 1 to supply power to the metal armor layer 2-2. When the temperature detected by the temperature sensor 5 is not lower than the preset high temperature threshold, the temperature control module 6 controls the SELV power module 1 to stop supplying power to the metal armor layer 2-2.

[0031] The above scheme operates as follows: When the ambient temperature drops to or below the preset low-temperature threshold, temperature sensor 5 transmits a temperature signal to temperature control module 6. Temperature control module 6 controls SELV power module 1 to supply power to metal armor layer 2-2 through electrode interfaces. Current flows into metal armor layer 2-2 from positive interface 3, flows along the entire length of metal armor layer 2-2, and flows back to SELV power module 1 from negative interface 4, forming a closed DC loop. When current flows through metal armor layer 2-2, Joule heat is generated according to Joule's law Q=I²Rt, and the heat is conducted towards cable core 2-1. Heat insulation layer 2-4 prevents excessive heat conduction, allowing heat to be transferred to cable core 2-1 at a controllable rate, ensuring that the fiber temperature rises within a safe range. When temperature sensor 5 detects that the temperature reaches or exceeds the preset high-temperature threshold, temperature control module 6 controls SELV power module 1 to stop supplying power, metal armor layer 2-2 stops heating, and the fiber optic cable temperature is maintained between the preset low-temperature threshold and the preset high-temperature threshold, achieving closed-loop temperature control.

[0032] Preferably, the SELV power module 1 has a rated output potential of -48V DC to ground; that is, the positive terminal of the SELV power module 1 is connected to ground, and the negative terminal output potential is -48V (to ground). In some preferred embodiments, the SELV power module 1 is a built-in -48V DC power supply (SELV safety extra-low voltage) of the communication equipment, which directly drives the metal armor layer 2-2 of the armored optical cable 2 to generate heat, without the need for high-voltage insulation modification of the optical cable, without the need for a dedicated high-power power supply, significantly reducing the total system cost and greatly improving the ease of implementation.

[0033] Compared to AC power supply, DC power supply is more stable and does not generate eddy current losses in the metal armor layer 2-2, effectively ensuring heating efficiency and power supply safety. The metal armor layer 2-2, as the heating element, provides uniform heating and stable anti-freeze heating along the entire length of the optical cable.

[0034] Furthermore, in some embodiments, the preset low temperature threshold is set between 0°C and 2°C, for example, 0°C, 1°C, or 2°C; the preset high temperature threshold is set between 4°C and 6°C, for example, 4°C, 5°C, or 6°C.

[0035] In some preferred embodiments, the preset low-temperature threshold is 1°C, and the preset high-temperature threshold is 5°C. Under this design, when the temperature sensor 5 detects a temperature not exceeding 1°C, the temperature control module 6 initiates heating; when the temperature is equal to or higher than 5°C, the temperature control module 6 stops heating, ensuring that the optical cable temperature is maintained within the range of 1°C to 5°C. This temperature control range effectively prevents the optical cable from icing, avoids overheating that could affect fiber performance, and minimizes unnecessary heating time, further reducing system energy consumption.

[0036] Furthermore, in some embodiments, the armored optical cable 2 is a short-distance armored optical cable, with a single segment length not exceeding 500m. The reason for limiting the single segment length to within 500m is that an excessively long optical cable will result in an excessively high total resistance of the metal armor layer 2-2, leading to a decrease in the operating current under a fixed supply voltage, potentially resulting in insufficient heating power. At the same time, the line voltage drop will increase, with the voltage at the far end being significantly lower than that at the near end, easily causing uneven heating along the line, thus reducing the antifreeze effect.

[0037] Understandably, in some short-distance applications, the 500m length limit is sufficient to cover most inter-office connections or access network end segments, meeting standard anti-freezing requirements. For some long-distance applications, multiple 500m short armored optical cables can be connected in series, with each segment powered independently. Alternatively, the long-distance armored optical cable can be divided into multiple independently powered segments, each no longer than 500m. Grooves are cut at the nodes of each segment to install electrode interfaces, and these interfaces are waterproofed, insulated, and sealed. Circuit configuration enables independent control and coordinated operation of each segment, meeting the anti-freezing requirements of long-distance optical cable lines, ensuring sufficient and uniform heating power in each segment, and guaranteeing overall anti-freezing effectiveness.

[0038] Furthermore, in some embodiments, the positive terminal interface 3 and the negative terminal interface 4 include, but are not limited to, T-shaped interfaces; the positive terminal interface 3 is fitted and fixed to one axial end of the metal armor layer 2-2, and the positive terminal interface 3 is simultaneously connected to the steel strip armor layer 2-2b and the aluminum strip armor layer 2-2a; the negative terminal interface 4 is fitted and fixed to the other axial end of the metal armor layer 2-2, and the positive terminal interface 3 is simultaneously connected to the steel strip armor layer 2-2b and the aluminum strip armor layer 2-2a, so that the double-layer armor structure can be powered on and heated at the same time.

[0039] Furthermore, in some embodiments, the temperature sensor 5 is a DTS (Distributed Fiber Optic Temperature Measurement) system, with its temperature-measuring fiber laid along the length of the armored optical cable 2 on its outer surface. The DTS system can achieve continuous temperature monitoring along the entire length of the optical cable, with a monitoring accuracy of ±0.5℃. It can promptly detect local temperature anomalies, providing accurate full-line temperature feedback to the temperature control module 6, ensuring the temperature control system has a comprehensive understanding of the temperature status of the entire optical cable, and preventing damage to the optical cable due to localized overcooling or overheating. The temperature control logic is as follows: heating is initiated when the monitored temperature is not higher than a preset low-temperature threshold, and heating is stopped when the monitored temperature is not lower than a preset high-temperature threshold, maintaining the cable body temperature within the range of 2~5℃, effectively preventing icing and freezing. In some preferred embodiments, the system should also be equipped with overcurrent protection, overtemperature protection, and leakage protection to prevent safety accidents such as localized short circuits in the metal armor layer 2-2 and overheating damage to the sheath.

[0040] In some other embodiments, the temperature sensor 5 may also be a Pt100 platinum resistance temperature sensor. The Pt100 platinum resistance temperature sensor is installed at both ends and / or the middle of the armored optical cable 2. Its principle is existing technology and will not be described in detail here.

[0041] Taking a 500m single-segment optical cable as an example, the resistance of the inner steel tape armor layer 2-2b is approximately 0.8Ω / 100m, and the resistance of the outer aluminum tape armor layer 2-2a is approximately 0.3Ω / 100m. The total resistance of the two armor layers in series is calculated as follows: Ω; The operating current is calculated as follows at -48V: ; The total power is calculated as follows: ; The power density per unit length is calculated as follows: q ; in, This represents the total resistance after series connection, where U is the operating voltage and I is the operating current. Where L is the total power, L is the length of the optical cable, and q is the power density per unit length.

[0042] The above design forms a double-armored layer series structure, requiring a lower operating current, making it suitable for scenarios with lower heat dissipation requirements, such as short-distance laying in southern winters where temperatures do not fall below -5°C. It meets basic anti-condensation requirements and avoids energy waste. In this design, the outer aluminum tape armor layer 2-2a also provides additional mechanical protection. Compared to single-layer steel tape armored optical cables, this design significantly improves tensile strength and lateral pressure resistance (e.g., tensile strength increases by approximately 20%, and lateral pressure resistance increases by approximately 15%), making it suitable for laying environments with rocky surfaces and high susceptibility to compression. An insulation layer can also be installed between the two armor layers. This insulation layer uses a polyester film with a thickness of approximately 0.05mm and an insulation resistance of not less than 10MΩ, effectively preventing short circuits between the two armor layers and ensuring a stable and reliable series circuit. Simultaneously, the polyester film has good temperature resistance and can operate stably for extended periods in environments ranging from -40°C to 80°C, making it suitable for most outdoor laying scenarios.

[0043] It is important to understand that the electrode interface can be electrically connected to the metal armor layer 2-2 via welding, crimping, or bolting. The electrode interface is sealed to the outer sheath 2-3, without directly exposing the metal armor layer 2-2 inside the outer sheath 2-3. Welding connections offer low contact resistance and high reliability, making them suitable for scenarios requiring high connection stability. Crimping connections facilitate assembly and are suitable for mass production. Bolted connections facilitate disassembly and maintenance, making them suitable for scenarios requiring frequent repairs. Different connection methods can be flexibly selected according to actual engineering needs, all ensuring a reliable electrical connection between the electrode interface and the metal armor layer 2-2.

[0044] It's important to understand that the term "and / or" describes a relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. In this article, the symbol " / " indicates that the related objects are in an "or" relationship, such as A / B meaning A or B.

[0045] It should be understood that expressions such as "comprising" and "may include" as used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "comprising" and / or "having" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but should not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0046] It should be understood that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0048] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0049] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An armored optical cable, characterized in that, It includes, from the inside out, a cable core (2-1), a metal armor layer (2-2), and an outer sheath (2-3); The two axial ends of the metal armor layer (2-2) are used to connect to an external SELV power module through an electrode interface to form a closed DC circuit; the metal armor layer (2-2) generates Joule heat through the closed DC circuit to prevent the armored optical cable from freezing.

2. The armored optical cable as described in claim 1, characterized in that, The metal armor layer (2-2) includes an aluminum strip armor layer (2-2a) and a steel strip armor layer (2-2b), wherein the aluminum strip armor layer (2-2a) is located outside the steel strip armor layer (2-2b).

3. The armored optical cable as described in claim 2, characterized in that, A heat insulation layer (2-4) is provided between the aluminum strip armor layer (2-2a) and the steel strip armor layer (2-2b).

4. The armored optical cable as described in claim 3, characterized in that, The heat insulation layer (2-4) is at least one of glass fiber tape, flame-retardant PET tape, and aramid fiber woven mesh layer.

5. The armored optical cable as described in claim 3 or 4, characterized in that, An inner sheath (2-5) is provided between the heat insulation layer (2-4) and the steel strip armor layer (2-2b).

6. A SELV-powered armored optical cable anti-freezing system, characterized in that, include: SELV power module (1); Armored optical cable (2) as described in any one of claims 1-5; The electrode interface includes a positive interface (3) and a negative interface (4). The positive interface (3) and the negative interface (4) are respectively disposed at both ends of the axial direction of the metal armor layer (2-2) and are electrically connected to the metal armor layer (2-2). The positive interface (3) is electrically connected to the positive terminal of the SELV power module (1), and the negative interface (4) is electrically connected to the negative terminal of the SELV power module (1) to form a closed DC circuit. The metal armor layer (2-2) generates Joule heating through the closed DC circuit. Temperature sensor (5), the temperature sensor (5) is used to monitor the temperature of the armored optical cable (2); Temperature control module (6), the temperature control module (6) is electrically connected to the temperature sensor (5) and the SELV power module (1), the temperature control module (6) is configured to: when the temperature detected by the temperature sensor (5) is not higher than the preset low temperature threshold, control the SELV power module (1) to supply power to the metal armor layer (2-2); When the temperature detected by the temperature sensor (5) is not lower than the preset high temperature threshold, the SELV power module (1) is controlled to stop supplying power to the metal armor layer (2-2).

7. The SELV-powered armored optical cable antifreeze system as described in claim 6, characterized in that, The positive terminal of the SELV power module (1) is grounded, and the negative terminal output potential is -48V.

8. The SELV-powered armored optical cable anti-freezing system as described in claim 6, characterized in that, The temperature sensor (5) is a distributed fiber optic temperature measurement system or a Pt100 platinum resistance temperature sensor (5).

9. The SELV-powered armored optical cable anti-freezing system as described in claim 6, characterized in that, The preset low temperature threshold is between 0℃ and 2℃, and the preset high temperature threshold is between 4℃ and 6℃.

10. The armored optical cable antifreeze system based on SELV power supply as described in any one of claims 6-9, characterized in that, The length of a single segment of the armored optical cable (2) is no more than 500m.

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