A high voltage power cable for smart grids

Abstract

The application discloses a high-voltage power cable for smart grids applied to the field of power cables, which comprises a wire core, a reinforcing wire arranged outside the wire core, a heat-conducting protective layer arranged outside, a raised portion corresponding to a heat exchange channel of a channel type insulation framework, a partition ring arranged at both ends of the channel type insulation framework, a flexible air-permeable structure or a drainage pipe arranged between adjacent partition rings, a heat-conducting insertion rod inserted into an outer insulation layer, and a heat-conducting insulation layer penetrating through the heat exchange channel and the raised portion and inserted into the wire core. The heat-conducting structure with multiple paths, such as the reinforcing wire, the heat-conducting protective layer and the heat-conducting insertion rod, can quickly conduct the heat generated by the wire core to the heat exchange channel, and then the heat is taken out of the cable through active air heat exchange, so that the situation that high temperature accelerates insulation aging is effectively avoided, and the service life of the cable is prolonged. Meanwhile, the design can be adapted to various laying scenes, such as straight lines and curves.

Description

Technical Field

[0001] This invention relates to the field of power cables, and in particular to a high-voltage power cable for smart grids. Background Technology

[0002] With the continuous advancement of smart grid construction, the transmission capacity and operational stability of high-voltage power cables are facing severe challenges. When transmitting large load currents, the conductor's inherent resistance generates significant Joule heat in the core, causing the cable's operating temperature to rise. If this heat cannot be dissipated in time, it will directly accelerate the aging of the insulation and sheathing materials, seriously threatening the cable's service life and the power grid's supply security.

[0003] Chinese invention patent CN114709024B discloses a high-voltage power cable. When the cable needs to be bent at a large angle, the annular cavity is heated by a heating device, which increases the fluidity of the filler. When the cable is bent, the filler in the annular cavity flows towards the outer periphery of the bend, thereby ensuring the insulation thickness of the outer sheath after bending and reducing the impact of excessive stretching of the outer sheath on the cable insulation.

[0004] Chinese invention patent CN121394031B discloses a heat dissipation flexible cable, including an inner sheath, a heat dissipation component, a separator component, and multiple battery cell components. The battery cell components include an electrical unit, a thermal expansion structure, and a first elastic element. The thermal expansion structure is configured to drive the electrical unit and the sliding component to move towards the inner sheath until they abut against the inner sheath when heated. The heat dissipation component can dissipate heat to the electrical unit and the optical unit through the inner sheath.

[0005] However, existing cables primarily rely on natural convection for heat dissipation during operation. In high ambient temperatures or under duct laying conditions, their heat dissipation performance significantly decreases, leading to increased core temperature and increasing the risk of insulation breakdown. While some cables incorporate vents to enhance airflow, this reduces the cable's airtightness, allowing moisture intrusion and causing a decrease in insulation resistance, thus posing a safety hazard. Furthermore, both the filler and insulation layers of these cables are solid structures without directional heat exchange channels, hindering the orderly removal of heat. Summary of the Invention

[0006] The core of this invention lies in solving the contradiction between heat dissipation and waterproof / moisture-proof performance, as well as the difficulty in dissipating internal heat accumulation, in existing high-voltage cables by using built-in directional heat exchange channels and a flexible, breathable structure. It also achieves efficient heat dissipation in different laying scenarios, while maintaining both structural strength adaptability and ease of maintenance.

[0007] To solve the above problems, the present invention adopts the following technical solution.

[0008] A high-voltage power cable for smart grids includes a core, which is composed of a conductor bundle and a thermally conductive insulation layer. Multiple reinforcing wires are arranged in a circular pattern on the outer side of the core. A thermally conductive protective layer is wrapped around the outside of the reinforcing wires. The thermally conductive protective layer includes a thermally conductive base layer. Multiple protrusions are provided at the inner end of the thermally conductive base layer, and the protrusions are positioned between two adjacent reinforcing wires and respectively attached to the two reinforcing wires. Multiple channel-type insulating frames are sleeved on the outer side of the thermally conductive protective layer, and an outer insulation layer is wrapped around the outer side of the channel-type insulating frames.

[0009] The channel-type insulating frame has multiple evenly distributed heat exchange channels, and each protrusion corresponds to one heat exchange channel; both ends of the channel-type insulating frame are connected to a partition ring, and the partition ring has a through hole that communicates with the heat exchange channel; a flexible ventilated structure or a drainage pipe can be detachably installed between two adjacent partition rings.

[0010] Multiple heat-conducting plugs are inserted into the outer insulation layer. Each heat-conducting plug penetrates the heat exchange channel and the protrusion and is inserted into the heat-conducting insulation layer of the wire core.

[0011] Furthermore, the separator ring includes a base ring on which a flange ring for mounting the corrugated sleeve assembly is fixedly connected. Through holes are formed on the base ring, and each through hole is connected to a heat exchange channel on the channel-type insulating frame on the same axis to form a continuous axial airflow channel.

[0012] Furthermore, both the reinforcing wire and the thermally conductive protective layer are made of thermally conductive materials, allowing airflow to exchange heat with the reinforcing wire and the thermally conductive protective layer through the heat exchange channel.

[0013] Furthermore, the flexible breathable structure is a waterproof and breathable membrane, and a flexible protective net covering the waterproof and breathable membrane is connected between the two separating rings.

[0014] Furthermore, the flexible breathable structure is a corrugated sleeve assembly, which includes a pair of corrugated tubes connected by a connecting ring, and a temperature-controlled breathable valve is installed on the connecting ring.

[0015] Furthermore, the temperature-controlled vent valve includes a heat-conducting pipe that passes through the connecting ring. The output end of the heat-conducting pipe is connected to a valve cover. An exhaust channel is opened inside the valve cover. A valve disc is connected inside the exhaust channel via a compression spring. A thermal expansion ring that matches the valve disc is connected inside the heat-conducting pipe.

[0016] Furthermore, the heat-conducting plug includes a heat-conducting post, the radial outer end of which is connected to a heat dissipation cap, which is embedded in the outer insulating layer.

[0017] Furthermore, a thermally conductive sealing film is connected between the heat dissipation cover and the surface of the outer insulation layer, and a thermochromic coating is locally applied to the thermally conductive sealing film.

[0018] Compared with the prior art, the advantages of this invention are:

[0019] (1) The present invention adopts a multi-path heat conduction combined with active airflow heat exchange design. Through the multi-path heat conduction structure such as reinforced wire, heat conduction protective layer and heat conduction plug, the heat generated by the wire core can be quickly conducted to the heat exchange channel, and then the heat is carried out of the cable through active airflow heat exchange, which effectively avoids the situation of high temperature accelerating insulation aging and extends the service life of the cable. At the same time, the design can also be adapted to various laying scenarios such as straight lines and bends, providing a good solution for different engineering needs.

[0020] (2) This solution can orderly export internal heat through built-in directional heat exchange channels and flexible breathable structure. The flexible breathable structure can effectively block the intrusion of external water vapor and dust while ensuring air circulation, thus achieving efficient heat dissipation in different laying scenarios. This design has both structural strength adaptability and operation and maintenance convenience. Whether it is straight laying or curved laying, it can maintain good heat dissipation performance and structural stability, which greatly reduces the difficulty and cost of operation and maintenance. Attached Figure Description

[0021] Figure 1 This is a partial perspective view of the installation of the drainage tube in this invention;

[0022] Figure 2 This is a cross-sectional view of the drainage tube of the present invention;

[0023] Figure 3 This is a partial perspective view of the waterproof and breathable membrane being installed according to the present invention;

[0024] Figure 4 A cross-sectional view of the bent state when the waterproof and breathable membrane of the present invention is installed;

[0025] Figure 5 This is a cross-sectional view of the heat-conducting insert of the present invention;

[0026] Figure 6 for Figure 5 Schematic diagram of the structure at point A;

[0027] Figure 7 A cross-sectional view of the present invention when the corrugated sleeve assembly is installed;

[0028] Figure 8 This is a cross-sectional view of the corrugated sleeve assembly of the present invention;

[0029] Figure 9 for Figure 8 A schematic diagram of the structure at point B.

[0030] Explanation of the labels in the diagram:

[0031] 1. Core wire; 2. Reinforcing wire; 3. Thermally conductive protective layer; 31. Thermally conductive base layer; 32. Raised part; 4. Channel-type insulation skeleton; 5. Outer insulation layer; 6. Separating ring; 61. Base ring; 62. Flange ring; 7. Waterproof and breathable membrane; 8. Corrugated sleeve assembly; 81. Corrugated pipe; 82. Connecting ring; 83. Temperature-controlled vent valve; 831. Heat-conducting pipe; 832. Valve cover; 833. Valve disc; 834. Thermal expansion ring; 9. Drainage pipe; 10. Thermally conductive insert; 101. Heat-conducting column; 102. Heat dissipation cover. Detailed Implementation

[0032] The technical solutions will now be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

[0033] First implementation method:

[0034] Please see Figures 1-6 A high-voltage power cable for smart grids includes a conductor core 1, which is composed of a conductor bundle and a thermally conductive insulation layer. Multiple reinforcing wires 2 are arranged in a circular pattern on the outside of the conductor core 1. The outside of the multiple reinforcing wires 2 is covered with a thermally conductive protective layer 3. Both the reinforcing wires 2 and the thermally conductive protective layer 3 are made of thermally conductive material. Airflow can exchange heat with the reinforcing wires 2 and the thermally conductive protective layer 3 through the heat exchange channel.

[0035] The thermally conductive protective layer 3 includes a thermally conductive base layer 31. The inner end of the thermally conductive base layer 31 is provided with a plurality of protrusions 32. The protrusions 32 are disposed between two adjacent reinforcing lines 2 and are respectively attached to the two reinforcing lines 2. The outer side of the thermally conductive protective layer 3 is provided with a multi-segment channel-type insulating skeleton 4. The outer side of the channel-type insulating skeleton 4 is covered with an outer insulating layer 5, which is made of cross-linked polyethylene material.

[0036] The channel-type insulating frame 4 has multiple uniformly distributed heat exchange channels, and each protrusion 32 corresponds to a heat exchange channel. Both ends of the channel-type insulating frame 4 are connected to a partition ring 6, and the partition ring 6 has through holes that communicate with the heat exchange channels. The partition ring 6 includes a base ring 61, on which a flange ring 62 for installing the corrugated sleeve assembly 8 is fixedly connected. Through holes are opened on the base ring 61, and each through hole communicates with a heat exchange channel on the channel-type insulating frame 4 on the same axis to form a continuous axial airflow channel.

[0037] A flexible ventilated structure or a drain pipe 9 can be detachably installed between two adjacent partition rings 6. The drain pipe 9 is equipped with an air supply and discharge interface. The drain pipe 9 is connected to an external air pump through the air supply and discharge interface, and airflow is introduced or discharged into the heat exchange channel through the drain pipe 9.

[0038] Multiple heat-conducting rods 10 are inserted into the outer insulation layer 5. Each heat-conducting rod 10 passes through the heat exchange channel and the protrusion 32 and is inserted into the heat-conducting insulation layer of the wire core 1. The heat-conducting rod 10 includes a heat-conducting column 101. A heat dissipation cover 102 is connected to the radial outer end of the heat-conducting column 101. The heat dissipation cover 102 is embedded in the outer insulation layer 5. A heat-conducting sealing film is connected between the heat dissipation cover 102 and the surface of the outer insulation layer 5.

[0039] Optionally, a thermochromic coating is partially applied to the thermally conductive sealing film (the thermochromic coating is set by a person skilled in the art using a suitable coating from the prior art); the thermochromic coating changes color when the temperature reaches 70±5℃, and changes color with temperature when a local overheating fault occurs in the cable, which facilitates the operation and maintenance personnel to quickly locate abnormal heat points during daily inspections, greatly reduces the difficulty of cable fault diagnosis, and improves the operation and maintenance efficiency of the smart grid.

[0040] In this embodiment, a drain pipe 9 is used to connect two separator rings 6 in the straight section of the cable; the drain pipe 9 is made of rigid material and is sealed to the separator rings 6.

[0041] In this embodiment, a flexible and breathable structure is used to connect two separating rings 6 in the curved section of the cable. Specifically, the flexible and breathable structure is a waterproof and breathable membrane 7. A flexible protective net covering the waterproof and breathable membrane 7 is connected between the two separating rings 6. The flexible protective net is a metal wire braided mesh. The flexible protective net is used to block debris in the external environment and adapt to the curved path of the cable. The waterproof and breathable membrane 7 is used to achieve natural heat dissipation of the cable and adapt to the curved path of the cable.

[0042] In actual operation, the cable of this embodiment utilizes the built-in channel to achieve heat dissipation as follows:

[0043] After the cable assembly is completed in the straight laying section, the two ends of the rigid drain pipe 9 are sealed and connected to the flange rings 62 of the two adjacent separator rings 6 respectively, so that each through hole on the base ring 61 is connected to the heat exchange channel on the corresponding channel-type insulation skeleton 4 and the interior of the drain pipe 9, forming multiple continuous and through axial airflow channels throughout the entire section. Then, the air supply and exhaust ports at both ends of the drain pipe 9 are connected to the external air supply device and the exhaust device respectively.

[0044] During cable operation under load, the heat generated by the core 1 is first conducted to the reinforcing wire 2 made of thermally conductive material. Subsequently, the heat is further conducted to the thermally conductive base layer 31 and the protrusion 32 of the thermally conductive protective layer 3. The protrusion 32 is located between two adjacent reinforcing wires 2, which can quickly receive the heat conducted by the reinforcing wire 2 and directly transfer the heat to the inner wall of the corresponding heat exchange channel. At the same time, the thermally conductive insert 10 that penetrates the heat exchange channel and the protrusion 32 will conduct the heat in the area outward synchronously, further improving the efficiency of heat transfer to the heat exchange channel.

[0045] After the external air supply device is activated, the cooling airflow enters the drain pipe 9 through the air supply interface, and then is evenly distributed to each heat exchange channel through the through hole of the base ring 61. When the airflow flows axially in the heat exchange channel, it directly contacts the inner wall of the heat exchange channel and the heat-conducting plug 10 for heat exchange, and quickly removes the heat discharged from the inside of the cable. The airflow carrying heat continues to flow along the axial airflow channel, and after passing through the drain pipe 9 which is connected by multiple channel-type insulation skeletons 4 and partition rings 6, it is finally discharged to the outside of the cable from the air supply interface at the other end. When the airflow passes through the waterproof and breathable membrane 7 of the curved section, it can also be discharged outward from the waterproof and breathable membrane 7.

[0046] Continuous airflow heat exchange can continuously carry away the heat generated by the operation of the conductor 1 from the cable, which greatly improves the heat dissipation efficiency compared with traditional natural heat dissipation and avoids the cable from running at high temperature for a long time and accelerating insulation aging. At the same time, the structure of the straight section using rigid drainage tube 9 can ensure that the airflow channel is sealed and stable, with no airflow leakage loss, and the heat dissipation efficiency is stable and controllable. It can also be combined with the circumferentially distributed reinforcing wire 2 to further improve the structural strength of the straight section of the cable and extend the overall service life of the cable.

[0047] This solution enables efficient heat dissipation of high-voltage cables in different laying scenarios, while also providing structural strength adaptability and ease of maintenance. In curved laying sections, the flexible waterproof and breathable membrane can adapt to the cable bending deformation, ensuring unobstructed airflow in the heat exchange channel and preventing channel blockage or breakage due to cable bending. The waterproof and breathable membrane can also prevent external moisture and dust from entering the cable while allowing airflow to complete heat exchange. Combined with the external flexible protective net, it enhances the bending damage resistance of the curved section and ensures the structural and heat dissipation stability of the curved section.

[0048] This solution combines multi-path heat conduction with active airflow heat exchange, which effectively avoids high-temperature-accelerated insulation aging and extends cable life compared to traditional passive heat dissipation. It is also suitable for various laying scenarios such as straight lines and bends.

[0049] Second implementation method:

[0050] The difference between this implementation method and the first implementation method is that:

[0051] Please see Figures 1-2 and Figures 5-9 In this embodiment, the flexible breathable structure is a corrugated sleeve assembly 8, which includes a pair of corrugated tubes 81, a connecting ring 82 connecting the pair of corrugated tubes 81, and a temperature-controlled breathable valve 83 installed on the connecting ring 82.

[0052] The temperature-controlled vent valve 83 includes a heat-conducting pipe 831 that passes through a connecting ring 82. The output end of the heat-conducting pipe 831 is connected to a valve cover 832. An exhaust channel is provided inside the valve cover 832, and a valve disc 833 is connected to the exhaust channel via a compression spring. A thermal expansion ring 834, matching the valve disc 833, is connected inside the heat-conducting pipe 831. When the temperature inside the corrugated sleeve assembly 8 is too high, the heat-conducting pipe 831 conducts heat to the thermal expansion ring 834 (the thermal expansion ring 834 can specifically be a hollow heat-conducting ring, storing thermal expansion fluid inside, and a piston ring is provided inside the hollow heat-conducting ring, with a useful...). The push rod that drives the valve disc 833 has a matching insertion hole on the hollow heat-conducting ring. The thermal expansion fluid is a liquid with a high coefficient of thermal expansion, such as a mixture of kerosene or ethanol. When the temperature rises, the volume expands, pushing the piston ring upward, which in turn drives the push rod to open the valve disc 833, thus opening the exhaust passage. The thermal expansion ring 834 expands when heated, pushing the valve disc 833 to open the exhaust passage, allowing the high-temperature airflow to be discharged to the external environment through the exhaust passage. When the temperature drops, the thermal expansion ring 834 contracts and resets, and the valve disc 833 resets under the action of the compression spring to re-close the exhaust passage, realizing automatic opening and closing under temperature control.

[0053] In actual operation, the cable of this embodiment utilizes the built-in channel to achieve heat dissipation as follows:

[0054] After the cable assembly is completed in the curved laying section, the ends of a pair of corrugated pipes 81 of the corrugated sleeve assembly 8 are respectively fixed to the flange rings 62 of the two adjacent separator rings 6, ensuring that the interior of the corrugated sleeve assembly 8 and all corresponding through holes on the base rings 61 at both ends are sealed and connected. This connects the heat exchange channels on the two adjacent channel-type insulation skeletons 4 into a complete axial airflow channel. The corrugated pipes 81 can be adapted and adjusted synchronously with the bending deformation of the cable to always maintain the connectivity of the airflow channel and meet the structural adaptation requirements of the curved laying section.

[0055] During cable operation under load, the heat generated by the conductor 1 is first conducted to the reinforcing wire 2 made of thermally conductive material. Subsequently, the heat is further conducted to the thermally conductive base layer 31 and the protrusion 32 of the thermally conductive protective layer 3. After receiving the heat conducted by the reinforcing wire 2, the protrusion 32 directly transfers it to the inner wall of the corresponding heat exchange channel. At the same time, the thermally conductive insert 10 that penetrates the heat exchange channel and the protrusion 32 will conduct the heat in the area to the heat exchange channel in a synchronous manner, improving the efficiency of heat transfer to the heat exchange channel, so that the air temperature in the heat exchange channel gradually increases as the cable operates.

[0056] When the cable load is normal and the overall temperature in the heat exchange channel is within the preset safe range, the heat conducted from the heat pipe 831 of the temperature control vent valve 83 to the thermal expansion ring 834 is insufficient to cause it to deform sufficiently. The valve disc 833 remains closed under the elastic force of the compression spring, blocking the exhaust channel in the valve cover 832. The entire axial airflow channel remains closed, and the cooling requirement can be met by relying solely on natural airflow convection and structural heat conduction to dissipate heat outward. At the same time, the closed structure can prevent external moisture and dust from entering the cable.

[0057] When the cable operates under high load for an extended period, and the temperature inside the heat exchange channel rises above the preset safety threshold, the high-temperature heat inside the corrugated sleeve assembly 8 is rapidly transferred to the thermal expansion ring 834 through the heat conduction pipe 831. The thermal expansion ring 834 expands and elongates due to the heat, overcoming the elastic force of the compression spring and pushing the valve disc 833 to move, opening the exhaust channel. At this time, the high-temperature airflow accumulated inside the heat exchange channel can be directly discharged to the external environment through the opened exhaust channel. The cooler external air will enter each heat exchange channel from the other end of the axial airflow channel, forming natural convection heat exchange, quickly carrying away the heat exported from inside the cable and reducing the overall temperature of the cable.

[0058] When the cable load decreases and the internal temperature drops to a safe threshold, the thermal expansion ring 834 cools and contracts to reset, and the valve disc 833 moves in the opposite direction to reset under the action of the compression spring, re-sealing the exhaust channel, blocking the connection between the inside of the cable and the outside world, preventing external impurities from entering and corroding the internal structure of the cable for a long time, and ensuring the insulation performance of the cable.

[0059] This embodiment uses a corrugated sleeve assembly 8 to connect the curved laying section, which not only adapts to the deformation requirements of cable bending, but also achieves automatic temperature control and heat dissipation by relying on the temperature-controlled vent valve 83, reducing the supporting construction cost, taking into account the flexibility of cable laying, heat dissipation efficiency and operational safety, and effectively extending the service life of the cable in the curved section.

[0060] The solution of this embodiment can achieve efficient heat dissipation of high-voltage cables in different laying scenarios. Compared with the use of waterproof and breathable membrane 7 in the bending section in the first embodiment, the design of the corrugated sleeve assembly 8 with temperature-controlled vent valve 83 in this embodiment can not only adapt to the bending laying requirements of the cable by the deformation of the corrugated pipe to ensure that the airflow channel is always connected, but also achieve automatic opening and closing of heat dissipation triggered by temperature by relying on the temperature-controlled vent valve 83. Moreover, the corrugated pipe is less prone to damage than the waterproof and breathable membrane 7 and is suitable for laying paths in complex environments.

[0061] In this embodiment, when the cable is running under normal load, the closed temperature-controlled vent valve 83 of the corrugated sleeve assembly 8 can effectively block the intrusion of external moisture and dust, protecting the internal insulation performance of the cable. When the cable is overheated under high load, the exhaust channel can be automatically opened to form natural heat dissipation. Especially when used in conjunction with the drain pipe 9, the airflow output from the drain pipe 9 enters the corrugated sleeve assembly 8 after passing through the heat exchange channel of the channel-type insulation skeleton 4, and can be discharged through the opened temperature-controlled vent valve 83, realizing the rapid discharge of the airflow after heat exchange and further improving the heat dissipation efficiency.

[0062] The above description is merely a preferred embodiment of the present invention; it encompasses all the protection scope of the present invention. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solutions and improved concepts of the present invention, should be covered within the protection scope of the present invention.

Claims

1. A high-voltage power cable for smart grids, comprising a conductor core (1), wherein the conductor core (1) is composed of a conductor bundle and a thermally conductive insulation layer, and a plurality of reinforcing wires (2) arranged in a circular pattern are disposed on the outer side of the conductor core (1), characterized in that: The outer sides of the multiple reinforcing wires (2) are covered with a thermally conductive protective layer (3). The thermally conductive protective layer (3) includes a thermally conductive base layer (31). The inner end of the thermally conductive base layer (31) is provided with multiple protrusions (32). The protrusions (32) are located between two adjacent reinforcing wires (2) and are respectively attached to the two reinforcing wires (2). The outer side of the thermally conductive protective layer (3) is covered with a multi-segment channel-type insulating skeleton (4). The outer side of the channel-type insulating skeleton (4) is covered with an outer insulating layer (5). The channel-type insulating frame (4) has multiple uniformly distributed heat exchange channels, and each protrusion (32) corresponds to a heat exchange channel; both ends of the channel-type insulating frame (4) are connected to a partition ring (6), and the partition ring (6) has a through hole communicating with the heat exchange channel; a flexible ventilated structure or a drain pipe (9) can be detachably installed between two adjacent partition rings (6), and the drain pipe (9) is provided with a gas delivery interface; The outer insulation layer (5) has multiple heat-conducting plugs (10) inserted into it. Each heat-conducting plug (10) passes through the heat exchange channel and the protrusion (32) and is inserted into the heat-conducting insulation layer of the wire core (1).

2. The high-voltage power cable for smart grids according to claim 1, characterized in that: The separator ring (6) includes a base ring (61), on which a flange ring (62) for installing a corrugated sleeve assembly (8) is fixedly connected. The through holes are opened on the base ring (61), and each through hole is connected to a heat exchange channel on the channel-type insulating frame (4) on the same axis to form a continuous axial airflow channel.

3. A high-voltage power cable for smart grids according to claim 1, characterized in that: The reinforcing line (2) and the thermally conductive protective layer (3) are both made of thermally conductive materials, and the airflow can exchange heat with the reinforcing line (2) and the thermally conductive protective layer (3) through the heat exchange channel.

4. A high-voltage power cable for smart grids according to claim 1, characterized in that: The flexible breathable structure is a waterproof and breathable membrane (7), and a flexible protective net covering the waterproof and breathable membrane (7) is connected between the two separating rings (6).

5. A high-voltage power cable for smart grids according to claim 1, characterized in that: The flexible breathable structure is a corrugated sleeve assembly (8), which includes a pair of corrugated tubes (81), a connecting ring (82) connecting the pair of corrugated tubes (81), and a temperature-controlled breathable valve (83) installed on the connecting ring (82).

6. A high-voltage power cable for smart grids according to claim 5, characterized in that: The temperature-controlled vent valve (83) includes a heat-conducting pipe (831) that passes through a connecting ring (82). The output end of the heat-conducting pipe (831) is connected to a valve cover (832). An exhaust channel is provided inside the valve cover (832). A valve disc (833) is connected to the exhaust channel through a compression spring. A thermal expansion ring (834) that matches the valve disc (833) is connected inside the heat-conducting pipe (831).

7. A high-voltage power cable for smart grids according to any one of claims 1-6, characterized in that: The heat-conducting plug (10) includes a heat-conducting column (101), and a heat dissipation cover (102) is connected to the radial outer end of the heat-conducting column (101). The heat dissipation cover (102) is embedded in the outer insulating layer (5).

8. A high-voltage power cable for smart grids according to claim 7, characterized in that: A thermally conductive sealing film is connected between the surface of the heat dissipation cover (102) and the surface of the outer insulation layer (5), and a thermochromic coating is partially coated on the thermally conductive sealing film.

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