Water-blocking type medium and high voltage power cable

Abstract

The application discloses a water-blocking type middle-high voltage power cable and relates to the technical field of cables, which comprises an oxygen-free copper conductor and further comprises: a first heat-conducting glue layer, a conductor shielding layer, a cross-linked polyethylene layer, a heat insulation layer, a second heat-conducting glue layer, a water-blocking layer, an armoring layer and an outer sleeve which are sequentially arranged on the oxygen-free copper conductor from inside to outside; wherein the heat insulation layer is composed of a plurality of heat insulation strips, the plurality of heat insulation strips are circumferentially distributed on the outside of the cross-linked polyethylene layer, a heat dissipation channel is formed between two adjacent heat insulation strips, and a self-adjusting temperature guiding assembly is arranged in the heat dissipation channel; and the self-adjusting temperature guiding assembly is arranged in the heat dissipation channel. The application realizes precise self-adaptive temperature control adjustment, through the synergistic effect of a phase change medium and a memory metal, automatic switching of high-temperature heat dissipation and low-temperature temperature locking can be realized without external power supply and electric control devices, the problems of single temperature control and response lag of traditional cables are effectively avoided, the stable operation temperature of the cable is ensured, and performance degradation caused by abnormal temperature is prevented.

Description

Technical Field

[0001] This invention belongs to the field of cable technology, and more specifically, relates to a water-blocking medium and high voltage power cable. Background Technology

[0002] Medium and high voltage power cables, as the core carrier of power transmission systems, are widely used in various scenarios such as urban power grids, industrial plants, and cold and humid regions. Their operational reliability is directly related to the stable power supply of the power system. With the increase in power transmission capacity and the increasingly complex laying environment, the market has placed higher demands on the comprehensive performance of medium and high voltage power cables, including heat conduction and heat dissipation, water resistance and moisture prevention, low temperature adaptability, and structural stability.

[0003] A search revealed that patent document CN214175760U, published on 2021-09-10, discloses a water-resistant high-voltage power cable, comprising three cables. A first rubber layer is fixedly connected to the outer wall of each cable, and a heat dissipation layer is fixedly connected to the outer wall of the first rubber layer. A first galvanized steel strip armor layer is fitted over the three heat dissipation layers. A graphene layer is filled between the inner wall of the first galvanized steel strip armor layer and the outer walls of the three heat dissipation layers. This invention enhances its waterproof effect through the waterproof layer and the use of a waterproof coating layer. The second rubber layer enhances its wear resistance, making it safer and more durable. The inclusion of nano-silver powder and silicone rubber enhances the heat dissipation effect of the graphene layer and also assists in shielding electromagnetic radiation. The heat dissipation layer is made of a flexible, thermally conductive polymer material, which can quickly dissipate heat, ensuring the operational performance of this invention.

[0004] Although the aforementioned patents have made improvements in water-blocking and heat dissipation, they still have obvious technical defects and cannot meet the comprehensive operational needs of current medium and high voltage power cables under complex and harsh working conditions. Their temperature control function is singular and passive, focusing only on heat dissipation without any insulation structure, and cannot achieve coordinated control of heat preservation and heat dissipation. They are difficult to adapt to areas with large temperature variations, and cannot lock in the internal heat of the cable in low-temperature environments, which can easily lead to embrittlement of the cable insulation layer. In high-temperature environments, they cannot adaptively adjust the heat dissipation efficiency according to temperature changes and cannot adapt to complex working conditions with alternating high and low temperatures. Therefore, a water-blocking medium and high voltage power cable is proposed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a water-blocking medium and high voltage power cable that can overcome or at least partially solve the above problems.

[0006] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0007] A water-blocking medium- and high-voltage power cable includes an oxygen-free copper conductor and further comprises: a first thermally conductive colloid layer, a conductor shielding layer, a cross-linked polyethylene layer, a heat insulation layer, a second thermally conductive colloid layer, a water-blocking layer, an armor layer, and an outer jacket, which are sequentially and fixedly wrapped around the oxygen-free copper conductor from the inside out; wherein, the heat insulation layer is composed of multiple heat insulation strips, which are circumferentially distributed on the outside of the cross-linked polyethylene layer, and a heat dissipation channel is formed between two adjacent heat insulation strips, and a self-regulating temperature-conducting component is provided in the heat dissipation channel; the self-regulating temperature-conducting component adjusts the effective thermally conductive contact area between itself and the second thermally conductive colloid layer according to the temperature change of the cross-linked polyethylene layer; when the temperature of the cross-linked polyethylene layer exceeds the normal operating temperature threshold of the oxygen-free copper conductor, the effective thermally conductive contact area between the self-regulating temperature-conducting component and the second thermally conductive colloid layer increases; when the temperature of the cross-linked polyethylene layer is lower than the normal operating temperature threshold of the oxygen-free copper conductor, the effective thermally conductive contact area between the self-regulating temperature-conducting component and the second thermally conductive colloid layer decreases.

[0008] Preferably, the self-regulating temperature conduction component includes a heat-conducting strip disposed within a heat dissipation channel and a shape memory metal heat-conducting element coupled to the heat-conducting strip. A sealed cavity is disposed within the heat-conducting strip, and the sealed cavity is filled with a phase change medium. The phase change temperature range of the phase change medium is within the normal operating temperature threshold range of the oxygen-free copper conductor. When the phase change medium undergoes phase change and absorbs heat, the shape memory metal heat-conducting element is driven by the force generated by the expansion to deform or displace, increasing the effective thermal contact area with the second thermally conductive colloid layer. When the phase change medium cools and contracts, the shape memory metal heat-conducting element utilizes its own shape memory effect to reset, reducing the effective thermal contact area with the second thermally conductive colloid layer.

[0009] Preferably, the heat-conducting strip is fixedly connected to the cross-linked polyethylene layer, the cross-section of the heat-conducting strip is rectangular, and the sides of the rectangle are provided with inwardly recessed sidewalls.

[0010] Preferably, the shape memory metal thermal conductive component includes a thermally conductive plate with a peak-valley structure. Insertion plates are fixedly installed at both ends of the thermally conductive plate, and the insertion plates are fixedly connected to the thermal insulation strip. When the phase change medium absorbs heat and expands, the thermally conductive strip drives the thermally conductive plate to contact the second thermally conductive colloid layer, while the insertion plates undergo elastic deformation. When the phase change medium cools and contracts, the insertion plates utilize their own shape memory effect to drive the thermally conductive plate to reset.

[0011] Preferably, the inner ring of the second thermally conductive colloid layer is provided with an integrally formed embedded heat dissipation strip, and the side of the embedded heat dissipation strip facing the heat conduction plate is flat; when the phase change medium absorbs heat and expands, the heat conduction plate and the embedded heat dissipation strip come into contact, and the heat conduction plate drives the embedded heat dissipation strip to deform, thereby increasing the effective thermal contact area between the heat conduction plate and the embedded heat dissipation strip.

[0012] Preferably, the shape memory metal heat-conducting component is composed of symmetrically arranged heat-dissipating arc plates and heat-absorbing arc plates. A fixed base plate is fixedly installed on the heat-absorbing arc plate. The fixed base plate is fixedly connected to the heat-conducting strip, and the heat-conducting strip is fixedly connected to the cross-linked polyethylene layer.

[0013] Preferably, the inner ring of the second thermally conductive colloid layer is provided with an integrally formed embedded heat dissipation strip, and the side of the embedded heat dissipation strip facing the heat dissipation arc plate is a raised arc surface; when the phase change medium absorbs heat and expands, the heat dissipation arc plate abuts against the raised arc surface of the embedded heat dissipation strip, and the heat dissipation arc plate drives the embedded heat dissipation strip to deform and increase the effective thermal contact area between it and the heat dissipation arc plate.

[0014] Preferably, the self-regulating temperature conduction component includes a shape memory metal thermal conductive element disposed in the heat dissipation channel. One end of the shape memory metal thermal conductive element is fixedly connected to the outer ring of the cross-linked polyethylene layer. A sealed cavity is disposed inside the shape memory metal thermal conductive element, and the sealed cavity is filled with a phase change medium.

[0015] Preferably, the shape memory metal thermal conductive component includes an arc-shaped base plate fixedly connected to the cross-linked polyethylene layer, an arc-shaped waist tube with an inwardly recessed center is fixedly installed on the arc-shaped base plate, and an arc-shaped heat dissipation plate is fixedly installed at the other end of the arc-shaped waist tube; when the phase change medium absorbs heat and expands, the arc-shaped waist tube drives the arc-shaped heat dissipation plate to move towards the second thermally conductive colloid layer; when the arc-shaped heat dissipation plate comes into contact with the second thermally conductive colloid layer, the arc-shaped heat dissipation plate and the second thermally conductive colloid layer deform synchronously, increasing the effective thermally conductive contact area between the arc-shaped heat dissipation plate and the second thermally conductive colloid layer.

[0016] Preferably, a filler strip is provided in the heat dissipation channel, and the filler strip is in contact with the outer wall of the shape memory metal thermal conductive component.

[0017] 1. This invention achieves precise adaptive temperature control. Through the synergistic effect of phase change medium and shape memory metal, it can automatically switch between high-temperature heat dissipation and low-temperature temperature locking without the need for external power supply and electronic control device. This effectively avoids the problems of single temperature control and lag response in traditional cables, ensuring stable cable operating temperature and preventing performance degradation caused by abnormal temperature.

[0018] 2. This invention has reliable sealing and protection performance. Through the sealing effect of double-layer silicone gel, combined with a multi-dimensional protective structure, it effectively blocks moisture intrusion, avoids corrosion of oxygen-free copper conductor and aging of insulation layer. At the same time, through structural optimization, it reduces interface gaps and reduces the risk of short circuit.

[0019] 3. This invention has short-circuit high-temperature protection capability. Through the thermal buffering effect of the phase change medium and the adaptive adjustment of the shape memory metal, when a short circuit occurs in the cable and the temperature rises suddenly, it can quickly dissipate heat and buffer the temperature shock, prevent the insulation layer from being broken down due to the high temperature caused by the short circuit, avoid the expansion of electrical faults, and improve the safety and stability of cable operation.

[0020] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0021] In the attached diagram:

[0022] Figure 1 This is a three-dimensional structural diagram of a water-blocking medium- and high-voltage power cable proposed in this invention;

[0023] Figure 2 for Figure 1 Schematic diagram of the structure at point A;

[0024] Figure 3 Main cross-sectional view of a water-blocking medium- and high-voltage power cable proposed in this invention. Figure 1 ;

[0025] Figure 4 for Figure 3 Schematic diagram of the structure at point B;

[0026] Figure 5 This is a schematic diagram of the structure of a self-regulating temperature-conducting component for a water-blocking medium- and high-voltage power cable proposed in this invention. Figure 1 ;

[0027] Figure 6 Main cross-sectional view of a water-blocking medium- and high-voltage power cable proposed in this invention. Figure 2 ;

[0028] Figure 7 for Figure 6 Schematic diagram of the structure at point C;

[0029] Figure 8 This is a schematic diagram of the structure of a self-regulating temperature-conducting component for a water-blocking medium- and high-voltage power cable proposed in this invention. Figure 2 ;

[0030] Figure 9 Main cross-sectional view of a water-blocking medium- and high-voltage power cable proposed in this invention. Figure 3 ;

[0031] Figure 10 for Figure 9 Schematic diagram of the structure at point D;

[0032] Figure 11 This is a schematic diagram of the structure of a self-regulating temperature-conducting component for a water-blocking medium- and high-voltage power cable proposed in this invention. Figure 3 .

[0033] In the diagram: 1. Oxygen-free copper conductor; 2. First thermally conductive colloid layer; 3. Conductor shielding layer; 4. Cross-linked polyethylene layer; 5. Thermal insulation layer; 6. Second thermally conductive colloid layer; 61. Embedded heat dissipation strip; 7. Water-blocking layer; 8. Armoring layer; 9. Outer jacket; 10. Self-regulating temperature conduction component; 101. Heat conduction strip; 102. Concave sidewall; 103. Phase change medium; 104. Shape memory metal thermal conductive component; 1041. Heat conduction plate; 1042. Connecting plate; 1043. Fixing base plate; 1044. Heat dissipation arc plate; 1045. Arc-shaped heat dissipation plate; 1046. Arc-shaped base plate; 1047. Arc-shaped waist tube; 105. Filler strip. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] Reference Figures 1-11 A water-blocking medium- and high-voltage power cable includes an oxygen-free copper conductor 1, and further includes: a first thermally conductive colloid layer 2, a conductor shielding layer 3, a cross-linked polyethylene layer 4, a heat insulation layer 5, a second thermally conductive colloid layer 6, a water-blocking layer 7, an armor layer 8, and an outer jacket 9, which are sequentially wrapped and fixed on the oxygen-free copper conductor 1 from the inside to the outside.

[0036] The first thermally conductive colloid layer 2 is made of silicone gel material, which is injected and co-extruded simultaneously during the stranding process of the oxygen-free copper conductor 1. It completely fills the stranding gaps of the oxygen-free copper conductor 1 and achieves seamless adhesion with the oxygen-free copper conductor 1. The first thermally conductive colloid layer 2 can quickly dissipate the Joule heat generated by the oxygen-free copper conductor 1 during operation, avoiding excessive temperature rise due to heat accumulation. At the same time, it forms a dense seal on the stranding gaps of the oxygen-free copper conductor 1, preventing moisture and humidity from entering, preventing oxidation and corrosion of the oxygen-free copper conductor 1 and resistance increase. Through its own elastic properties, it buffers the structural stress generated by thermal expansion and contraction of the oxygen-free copper conductor 1, protecting the structural integrity of subsequent layers. This layer is in direct contact with the oxygen-free copper conductor 1. Relying on the chemical inertness of the silicone gel, it does not react chemically with copper, ensuring the long-term stable operation of the oxygen-free copper conductor 1. At the same time, it provides a smooth and dense support interface for the outer conductor shielding layer 3, ensuring that the conductor shielding layer 3 is uniformly covered without gaps or peeling.

[0037] The conductor shielding layer 3 is extruded onto the outside of the first thermally conductive colloid layer 2. Its core function is to uniformly distribute the electric field on the surface of the oxygen-free copper conductor 1, eliminate the electric field concentration caused by the microscopic sharp points and corners formed by the twisting of the oxygen-free copper conductor 1, suppress the generation of partial discharge, and prevent the cross-linked polyethylene layer 4 from breaking down or aging due to electric field distortion, thus ensuring the electrical safety of the cable under high-voltage conditions. This layer is tightly bonded to the first thermally conductive colloid layer 2, which not only does not damage the sealing and thermal conductivity structure of the thermally conductive colloid layer, but also can receive the heat dissipated by the first thermally conductive colloid layer 2 and uniformly transfer it to the outer cross-linked polyethylene layer 4, realizing a reliable connection between the thermal conductivity structure and the electric field shielding. At the same time, it provides an equipotential and smooth bonding interface for the cross-linked polyethylene layer 4, ensuring that the cross-linked polyethylene layer 4 and the conductor shielding layer 3 form an integrated structure.

[0038] The cross-linked polyethylene layer 4, as the main insulation layer of the cable, is extruded on the outside of the conductor shielding layer 3. Its core function is to withstand the medium and high voltage of the system operation, achieve electrical isolation between the oxygen-free copper conductor 1 and the external environment, and prevent electrical faults such as leakage and breakdown. It is integrally formed with the conductor shielding layer 3 using a three-layer co-extrusion process, with no air gaps or contaminants at the interface, ensuring stable electrical insulation performance. At the same time, it provides a rigid and flat supporting substrate for the outer heat insulation layer 5, which facilitates the uniform coverage of the heat insulation layer 5 and avoids uneven heat insulation effect due to uneven interface. In addition, the cross-linked polyethylene layer 4 has good heat resistance and aging resistance, and can work with the heat insulation layer 5 to maintain its own stable operating temperature, further improving the long-term reliability of the cable.

[0039] The heat insulation layer 5 can be made of cross-linked polyolefin foam or silicone rubber foam and is set on the outside of the cross-linked polyethylene layer 4. It is composed of multiple heat insulation strips, which are evenly distributed in a circle on the outside of the cross-linked polyethylene layer 4. A heat dissipation channel is formed between two adjacent heat insulation strips. A self-regulating temperature conduction component 10 is set in the heat dissipation channel. The self-regulating temperature conduction component 10 can adjust the effective heat conduction contact area between itself and the second thermally conductive colloid layer 6 according to the temperature change of the cross-linked polyethylene layer 4. The specific working logic is as follows: when the temperature of the cross-linked polyethylene layer 4 exceeds the normal operating temperature threshold of the oxygen-free copper conductor 1, the effective heat conduction contact area between the self-regulating temperature conduction component 10 and the second thermally conductive colloid layer 6 increases, which accelerates the conduction of heat inside the cable to the second thermally conductive colloid layer 6, and avoids the cross-linked polyethylene layer 4 from aging due to overheating and the oxygen-free copper conductor 1 from having abnormal resistance due to excessive temperature.

[0040] When the temperature of the cross-linked polyethylene layer 4 is lower than the normal operating temperature threshold of the oxygen-free copper conductor 1 (the long-term normal operating temperature of the oxygen-free copper conductor is ≤90℃), the effective thermal contact area between the self-regulating temperature-conducting component 10 and the second thermally conductive colloid layer 6 is reduced, thereby reducing the loss of internal heat to the outside and locking in the internal heat.

[0041] Therefore, the core function of this layer is to maintain the temperature stability of the cross-linked polyethylene layer 4 and the oxygen-free copper conductor 1 in conjunction with the self-regulating temperature-conducting component 10 and the second thermally conductive colloid layer 6 when the external ambient temperature is low. This prevents the cross-linked polyethylene layer 4 from becoming brittle and cracking due to excessively low temperature, and prevents the oxygen-free copper conductor 1 from experiencing unstable resistance due to temperature fluctuations. At the same time, multiple circumferentially distributed heat insulation strips can effectively protect the cross-linked polyethylene layer 4, reducing the impact of the external environment on the insulation layer. The design of the heat dissipation channel between adjacent heat insulation strips does not affect the temperature regulation function of the self-regulating temperature-conducting component 10, and can also provide a channel for heat conduction, achieving the automatic temperature control effect of low-temperature locking and high-temperature heat dissipation.

[0042] The inner side of this layer is tightly bonded to the cross-linked polyethylene layer 4 to ensure smooth heat transfer, while the outer side is seamlessly connected to the second thermally conductive colloid layer 6. Utilizing the flexibility of the second thermally conductive colloid layer 6, it compensates for the thermal expansion and contraction differences between the insulation strip and the water-blocking layer 7, preventing gaps between layers. Simultaneously, one end of the self-regulating temperature-conducting component 10 is bonded to the outer side of the cross-linked polyethylene layer 4, and the other end is in contact with the second thermally conductive colloid layer 6, ensuring timely temperature signal transmission and precise thermal regulation. Working in conjunction with the first thermally conductive colloid layer 2, the cross-linked polyethylene layer 4, and the second thermally conductive colloid layer 6, it constructs an intelligent temperature control system, further improving the cable's operational stability and service life.

[0043] The second thermally conductive colloid layer 6 uses the same silicone gel material as the first thermally conductive colloid layer 2 and is wrapped around the outside of the insulation layer 5. On the one hand, it helps to dissipate residual heat inside the cable, and together with the first thermally conductive colloid layer 2 and the insulation layer 5, it further optimizes the overall thermal conductivity and insulation balance of the cable, ensuring the temperature stability of the oxygen-free copper conductor 1 and the cross-linked polyethylene layer 4. On the other hand, it provides flexible clamping force and buffering effect to the inner insulation layer 5, cross-linked polyethylene layer 4, and other structures, compensating for the differences in thermal expansion and contraction between layers and preventing interlayer slippage, peeling, or gaps. It protects the internal electrical insulation and heat insulation structure; on the other hand, it helps to improve the overall sealing performance of the cable, forming a double sealing system with the first thermally conductive colloid layer 2, further blocking the intrusion of moisture and humidity, and strengthening the water-blocking effect in conjunction with the water-blocking layer 7. The inner side of this layer is closely attached to the heat insulation layer 5, which can fill the tiny unevenness on the surface of the heat insulation layer 5, ensuring that the heat-locking effect of the heat insulation layer 5 is not compromised; the outer side is closely attached to the water-blocking layer 7, providing a smooth and dense support interface for the water-blocking layer 7, ensuring that the water-blocking layer 7 is uniformly covered, and avoiding water-blocking failure due to interface gaps.

[0044] The water-blocking layer 7 is located outside the second thermally conductive colloid layer 6. Its core function is to achieve dual radial and longitudinal water blocking of the cable, preventing external moisture and humidity from penetrating into the interior through the gaps between cable layers or the cable ends. It also prevents moisture from invading the cross-linked polyethylene layer 4, causing water treeing aging and a decline in insulation performance, and avoids moisture contact with the oxygen-free copper conductor 1, which would lead to oxidation and corrosion of the oxygen-free copper conductor 1. This ensures the long-term operation of the cable in harsh environments such as humidity and immersion, significantly improving the cable's moisture-proof and water-blocking capabilities, broadening the cable's applicable scenarios, and extending the cable's service life. This layer relies on the uniform support of the second thermally conductive colloid layer 6 to achieve complete coverage of all internal layers without omissions or gaps. At the same time, it works in conjunction with the sealing functions of the first thermally conductive colloid layer 2 and the second thermally conductive colloid layer 6 to construct a full-section sealed water-blocking system. The outer side is tightly bonded to the armor layer 8, and the rigid pressure of the armor layer 8 further improves the adhesion of the water-blocking layer 7 and enhances the water-blocking effect.

[0045] The armor layer 8 covers the outside of the water-blocking layer 7. Its main function is to provide mechanical protection for the cable, withstand tensile, compressive, and impact forces during cable laying, and prevent the cable from being damaged by external forces such as squeezing, dragging, or puncturing, thus protecting the internal insulation, heat conduction, and water-blocking structures. It also has anti-biting function to prevent damage to the cable from rodents, birds, etc. Its advantages are that it improves the mechanical strength and damage resistance of the cable, making it suitable for complex laying environments (such as direct underground burial, conduit laying, and high-altitude installation). This layer uses the water-blocking layer 7 and the second thermally conductive colloid layer 6 as flexible padding to prevent the rigid armor layer 8 from directly pressing on the inner water-blocking layer 7 and heat insulation layer 5, and to prevent the inner flexible layer from being indented or damaged. It achieves a synergistic effect of rigid protection and flexible buffering, protecting the internal structure without affecting the function of each layer. The outer side is tightly fitted with the outer jacket 9, providing stable support for the outer jacket 9 and ensuring that the outer jacket 9 is evenly covered.

[0046] The outermost protective structure of the cable, the outer jacket 9, covers the outside of the armor layer 8. Its core function is to isolate it from the erosion of the external environment. It has excellent weather resistance, oil resistance, corrosion resistance, and anti-aging properties, preventing damage to the internal layers of the cable caused by sunlight exposure, rain and snow erosion, soil corrosion, and chemical pollution. At the same time, it further enhances the mechanical protection and electrical insulation performance of the cable, prevents the armor layer 8 from oxidizing and rusting, and provides long-term and stable external protection for all internal functional layers. It can extend the overall service life of the cable and ensure stable operation of the cable in various complex environments. This layer is tightly fitted to the armor layer 8 and can fill the gaps on the surface of the armor layer 8 to form a complete external protective barrier. Together with the armor layer 8, it constructs a rigid and flexible dual external protection system, providing all-round protection for the internal structure of the cable.

[0047] In summary, this cable, through the coordinated operation of the insulation layer 5 and the self-regulating temperature-conducting component 10 within the heat dissipation channel, breaks away from the existing single temperature control mode that only dissipates heat without insulation or only insulates heat with poor heat dissipation performance. It can adaptively adjust the effective thermal contact area between the self-regulating temperature-conducting component 10 and the second thermally conductive colloid layer 6 according to the temperature change of the cross-linked polyethylene layer 4.

[0048] When the temperature of the cross-linked polyethylene layer 4 exceeds the normal operating temperature threshold of the oxygen-free copper conductor 1, the contact area is increased to accelerate heat dissipation and prevent the insulation layer from overheating and aging. When the temperature is lower than the normal operating temperature threshold, the contact area is reduced to lock in internal heat and prevent the insulation layer from becoming brittle and the resistance of the oxygen-free copper conductor 1 from fluctuating. Thus, the adaptive regulation of low-temperature temperature locking and high-temperature heat dissipation can stably adapt to harsh areas with alternating high and low temperatures and large temperature changes, greatly expanding the applicable scenarios of the cable.

[0049] The cable is equipped with a dual silicone gel thermally conductive colloid layer (first thermally conductive colloid layer 2 and second thermally conductive colloid layer 6). The first thermally conductive colloid layer 2 seamlessly fills the stranding gap of the oxygen-free copper conductor 1, quickly dissipating the Joule heat generated by the oxygen-free copper conductor 1 during operation and preventing heat accumulation. The second thermally conductive colloid layer 6 wraps the heat insulation layer 5 and the self-regulating temperature conduction component 10, assisting in the dissipation of residual heat. At the same time, it works in conjunction with the heat insulation layer 5 to form a synergistic effect of heat conduction, heat insulation, and intelligent heat dissipation. This not only solves the problem of insufficient heat dissipation efficiency in existing patents, but also makes up for the shortcomings of the lack of heat insulation structure. It effectively maintains the oxygen-free copper conductor 1 and the cross-linked polyethylene layer 4 in a relatively stable operating temperature range, improving the reliability of cable operation.

[0050] This cable employs a double seal of the first thermally conductive colloid layer 2 and the second thermally conductive colloid layer 6, along with a water-blocking layer 7, to construct a full-section sealed water-blocking system. This effectively prevents moisture and humidity from penetrating the stranding gaps of the oxygen-free copper conductor 1 and the interior of the cable, avoiding oxidation and corrosion of the oxygen-free copper conductor 1 and water treeing aging of the insulation layer. The water-blocking effect is also more reliable. At the same time, the elastic properties of the thermally conductive colloid layer can compensate for the differences in thermal expansion and contraction between the layers, preventing interlayer peeling and gap formation. Combined with the protective function of the heat insulation strip and the mechanical protection of the armor layer 8 and the outer jacket 9, the cable structure stability is further improved, making it suitable for complex laying environments such as humid and cold conditions.

[0051] In this cable, the conductor shielding layer 3 and the cross-linked polyethylene layer 4 are integrally formed by co-extrusion process, with no air gaps or contaminants at the interface. This effectively and uniformly distributes the electric field on the surface of the oxygen-free copper conductor 1, suppresses partial discharge, and prevents insulation layer breakdown or electrical tree aging, ensuring electrical safety under medium and high voltage conditions. At the same time, the synergistic effect of the heat insulation layer 5 and the self-regulating temperature conduction component 10 can reduce the impact of temperature fluctuations on the insulation layer performance, further improving the stability and service life of the cable's electrical insulation.

[0052] To achieve the aforementioned intelligent temperature control and comprehensive protection functions, this design provides the following three specific implementation methods, each using a self-adjusting temperature-conducting component 10 with a different structure to achieve adaptive regulation of low-temperature temperature locking and high-temperature heat dissipation, adapting to the usage requirements of different laying scenarios, as detailed below:

[0053] Example 1, refer to Figures 3-5 The self-regulating temperature conduction component 10 includes a heat-conducting strip 101 disposed in a heat dissipation channel and a shape memory metal heat-conducting element 104 coupled to the heat-conducting strip 101. A sealed cavity is provided in the heat-conducting strip 101, and the sealed cavity is filled with a phase change medium 103. The phase change temperature range of the phase change medium 103 is within the normal operating temperature threshold range of the oxygen-free copper conductor 1. When the phase change medium 103 undergoes phase change and absorbs heat and expands, the shape memory metal heat-conducting element 104 is driven by the force generated by the expansion to deform or displace, increasing the effective thermal contact area with the second thermally conductive colloid layer 6. When the phase change medium 103 cools and contracts, the shape memory metal heat-conducting element 104 uses its own shape memory effect to reset, reducing the effective thermal contact area with the second thermally conductive colloid layer 6.

[0054] The heat-conducting strip 101 is fixedly connected to the cross-linked polyethylene layer 4. The cross-section of the heat-conducting strip 101 is rectangular, and the side of the rectangle is provided with an inwardly recessed sidewall 102.

[0055] The shape memory metal heat-conducting component 104 includes a heat-conducting plate 1041 with a peak-valley structure. Insertion plates 1042 are fixedly installed at both ends of the heat-conducting plate 1041, and the insertion plates 1042 are fixedly connected to the heat insulation strip. When the phase change medium 103 absorbs heat and expands, the heat-conducting strip 101 drives the heat-conducting plate 1041 to contact the second heat-conducting colloid layer 6, while the insertion plates 1042 undergo elastic deformation. When the phase change medium 103 cools and contracts, the insertion plates 1042 utilize their own shape memory effect to drive the heat-conducting plate 1041 to reset.

[0056] The inner ring of the second thermally conductive colloid layer 6 is provided with an integrally formed embedded heat dissipation strip 61. The side of the embedded heat dissipation strip 61 facing the heat conduction plate 1041 is flat. When the phase change medium 103 absorbs heat and expands, the heat conduction plate 1041 and the embedded heat dissipation strip 61 come into contact. The heat conduction plate 1041 drives the embedded heat dissipation strip 61 to deform, thereby increasing the effective thermal contact area between the heat conduction plate 1041 and the embedded heat dissipation strip 61.

[0057] Among them, the phase change medium 103 can be selected from paraffin wax No. 52-60, wherein (the melting point of paraffin wax No. 52 is 50-54℃; the melting point of paraffin wax No. 56 is 54-58℃; the melting point of paraffin wax No. 58 is 56-60℃; and the melting point of paraffin wax No. 60 is 58-62℃).

[0058] During cable operation, the Joule heat generated by the oxygen-free copper conductor 1 is transferred to the cross-linked polyethylene layer 4, and then conducted to the sealed cavity of the heat-conducting strip 101. When the temperature of the cross-linked polyethylene layer 4 exceeds the normal operating temperature threshold of the oxygen-free copper conductor 1, the phase change medium 103 in the sealed cavity reaches the phase change temperature, undergoes a phase change, absorbs heat, and expands. The compressive force generated by the expansion acts on the concave sidewall 102 of the heat-conducting strip 101, driving the heat-conducting strip 101 to deform outward, thereby pushing the memory metal heat-conducting component 104 coupled with it to move synchronously. The heat-conducting plate 1041 (peak-valley structure, such as corrugated plate or sawtooth plate structure) of the memory metal heat-conducting component 104 approaches and contacts the embedded heat dissipation strip 61 of the second heat-conducting colloid layer 6. At the same time, the plug plates 1042 at both ends undergo elastic deformation under the driving force, and then further push the heat-conducting plate 1041 to fit tightly with the embedded heat dissipation strip 61, and the peak-valley structure of the heat-conducting plate 1041... After contacting the plane of the embedded heat dissipation strip 61, the embedded heat dissipation strip 61 is slightly deformed to fill the gap between the peaks and valleys, thereby significantly increasing the effective thermal contact area between the two and accelerating the transfer of heat inside the cable through the heat-conducting plate 1041 and the embedded heat dissipation strip 61 to the second thermally conductive colloid layer 6, achieving rapid heat dissipation. When the temperature of the cross-linked polyethylene layer 4 drops below the normal operating temperature threshold, the phase change medium 103 cools and contracts, the extrusion pressure in the sealed cavity disappears, and the plug plate 1042 of the shape memory metal thermal conductive component 104 resets using its own shape memory effect, causing the heat-conducting plate 1041 to separate from the embedded heat dissipation strip 61, reducing the effective thermal contact area and reducing the loss of internal heat to the outside, achieving a temperature-locking effect. The thermal conductive strip 101 is fixedly connected to the cross-linked polyethylene layer 4, and the plug plate 1042 is fixedly connected to the heat insulation strip, ensuring that the entire component is structurally stable during temperature changes and does not shift.

[0059] In summary, the phase change temperature range of the phase change medium 103 matches the normal operating temperature threshold of the oxygen-free copper conductor 1, and can quickly respond to the temperature change of the cross-linked polyethylene layer 4, realize timely adjustment of the thermally conductive contact area, and ensure precise control of high-temperature heat dissipation and low-temperature temperature locking.

[0060] The peak-valley structure heat-conducting plate 1041 works in conjunction with the embedded heat dissipation strip 61. After deformation, it can fully fill the contact gap and maximize the effective heat conduction contact area. At the same time, the heat-conducting strip 101 can quickly conduct the heat of the cross-linked polyethylene layer 4, improving the heat dissipation efficiency.

[0061] The dual fixation of the heat-conducting strip 101 and the cross-linked polyethylene layer 4, and the plug plate 1042 and the heat insulation strip, combined with the shape memory effect of the shape memory metal, ensures that the components do not loosen or shift during repeated temperature changes, resulting in a long service life.

[0062] The rectangular cross-section heat-conducting strip 101, combined with the concave sidewall 102, can flexibly adapt to the spatial dimensions of the heat dissipation channel, and has a simple structure, is easy to process and manufacture, and has controllable cost.

[0063] The second thermally conductive colloid layer 6 and its internal embedded heat dissipation strip 61 are integrally molded, which can realize rapid heat conduction without compromising the sealing performance of the second thermally conductive colloid layer 6, thus balancing temperature control and sealing.

[0064] Example 2: Refer to Figures 6-8 The self-regulating temperature conduction component 10 includes a heat-conducting strip 101 disposed in a heat dissipation channel and a shape memory metal heat-conducting element 104 coupled to the heat-conducting strip 101. A sealed cavity is provided in the heat-conducting strip 101, and the sealed cavity is filled with a phase change medium 103. The phase change temperature range of the phase change medium 103 is within the normal operating temperature threshold range of the oxygen-free copper conductor 1. When the phase change medium 103 undergoes phase change and absorbs heat and expands, the shape memory metal heat-conducting element 104 is driven by the force generated by the expansion to deform or displace, increasing the effective thermal contact area with the second thermally conductive colloid layer 6. When the phase change medium 103 cools and contracts, the shape memory metal heat-conducting element 104 uses its own shape memory effect to reset, reducing the effective thermal contact area with the second thermally conductive colloid layer 6.

[0065] The shape memory metal heat-conducting component 104 is composed of a symmetrically arranged heat-dissipating arc plate 1044 and a heat-absorbing arc plate. A fixed base plate 1043 is fixedly installed on the heat-absorbing arc plate. The fixed base plate 1043 is fixedly connected to the heat-conducting strip 101. The heat-conducting strip 101 is fixedly connected to the cross-linked polyethylene layer 4.

[0066] The inner ring of the second thermally conductive colloid layer 6 is provided with an integrally formed embedded heat dissipation strip 61. The side of the embedded heat dissipation strip 61 facing the heat dissipation arc plate 1044 is a raised arc surface. When the phase change medium 103 absorbs heat and expands, the heat dissipation arc plate 1044 abuts against the raised arc surface of the embedded heat dissipation strip 61. The heat dissipation arc plate 1044 drives the embedded heat dissipation strip 61 to deform and increase the effective thermal contact area between it and the heat dissipation arc plate 1044.

[0067] Among them, the phase change medium 103 can be selected from paraffin wax No. 52-60, wherein (the melting point of paraffin wax No. 52 is 50-54℃; the melting point of paraffin wax No. 56 is 54-58℃; the melting point of paraffin wax No. 58 is 56-60℃; and the melting point of paraffin wax No. 60 is 58-62℃).

[0068] During cable operation, the heat generated by the oxygen-free copper conductor 1 is transferred to the heat-conducting strip 101 via the cross-linked polyethylene layer 4. The heat-conducting strip 101 then directs the heat into the phase change medium 103 within the sealed cavity. When the temperature of the cross-linked polyethylene layer 4 exceeds the normal operating temperature threshold of the oxygen-free copper conductor 1, the phase change medium 103 undergoes a phase change, absorbs heat, and expands. The expansion force acts on the heat-conducting strip 101 and is then transferred through the fixed substrate 1043 to the heat-absorbing arc plate of the shape memory metal heat-conducting component 104. This drives the heat-absorbing arc plate to expand outward, causing the symmetrically arranged heat-dissipating arc plates 1044 to move synchronously towards the embedded heat dissipation strip 61 of the second thermally conductive colloid layer 6. After the heat-dissipating arc plate 1044 contacts the raised arc surface of the embedded heat dissipation strip 61, it undergoes adaptive deformation under the continuous action of the expansion force, tightly fitting the raised arc surface. The embedded heat sink 61 undergoes a slight deformation, significantly increasing the contact area between the two. Heat is rapidly transferred to the embedded heat sink 61 through the heat-absorbing arc plate and the heat-dissipating arc plate 1044, and then discharged through the second thermally conductive colloid layer 6, achieving efficient heat dissipation. When the temperature of the cross-linked polyethylene layer 4 is lower than the normal operating temperature threshold, the phase change medium 103 cools and contracts, the expansion force disappears, and the shape memory metal thermal conductive component 104 (heat-dissipating arc plate 1044, heat-absorbing arc plate) resets using its own shape memory effect. The heat-dissipating arc plate 1044 separates from the embedded heat sink 61, reducing the effective thermal contact area and minimizing internal heat loss, thus achieving heat preservation and temperature locking. The fixed connection between the fixed substrate 1043 and the thermal conductive strip 101, and between the thermal conductive strip 101 and the cross-linked polyethylene layer 4, ensures the stability of the component structure and smooth heat transfer.

[0069] In summary, the symmetrically arranged heat dissipation arc plate 1044 and heat absorption arc plate can achieve uniform heat reception and transfer, avoid local heat accumulation, and improve temperature control uniformity.

[0070] The heat dissipation arc plate 1044 and the raised arc surface of the embedded heat dissipation strip 61 are matched. After deformation, they can form a large area of ​​contact. Compared with the flat contact, the effective heat conduction contact area is increased more significantly, and the heat dissipation efficiency is higher.

[0071] The arc-shaped structure can better fit the circumferential contour of the heat dissipation channel, make full use of the heat dissipation channel space, reduce the space occupied by the components, and ensure synergistic cooperation with the thermal insulation strip and the second thermally conductive colloid layer 6.

[0072] The shape memory metal heat-conducting component 104 is firmly connected to the heat-conducting strip 101 through the fixed substrate 1043. The deformation and recovery process is stable and not prone to fatigue damage, and it is suitable for long-term repeated temperature changes.

[0073] The connection between the arc-shaped memory metal component and the heat-conducting strip 101 is simple and can be mass-produced. Furthermore, the raised arc surface design of the embedded heat sink 61 eliminates the need for complex processing techniques, thus reducing manufacturing costs.

[0074] Example 3, referring to Figures 9-11 The self-regulating temperature conduction component 10 includes a shape memory metal heat conduction component 104 disposed in the heat dissipation channel. One end of the shape memory metal heat conduction component 104 is fixedly connected to the outer ring of the cross-linked polyethylene layer 4. A sealed cavity is provided inside the shape memory metal heat conduction component 104, and the sealed cavity is filled with a phase change medium 103.

[0075] The shape memory metal thermal conductive component 104 includes an arc-shaped base plate 1046 fixedly connected to the cross-linked polyethylene layer 4. An arc-shaped waist tube 1047 with a central inward concavity is fixedly installed on the arc-shaped base plate 1046. An arc-shaped heat dissipation plate 1045 is fixedly installed at the other end of the arc-shaped waist tube 1047. When the phase change medium 103 absorbs heat and expands, the arc-shaped waist tube 1047 drives the arc-shaped heat dissipation plate 1045 to move towards the second thermally conductive colloid layer 6. When the arc-shaped heat dissipation plate 1045 comes into contact with the second thermally conductive colloid layer 6, the arc-shaped heat dissipation plate 1045 and the second thermally conductive colloid layer 6 deform synchronously, increasing the effective thermal contact area between the arc-shaped heat dissipation plate 1045 and the second thermally conductive colloid layer 6.

[0076] A filler strip 105 is provided inside the heat dissipation channel, and the filler strip 105 is attached to the outer wall of the shape memory metal heat conductor 104.

[0077] Among them, the phase change medium 103 can be selected from paraffin wax No. 52-60, wherein (the melting point of paraffin wax No. 52 is 50-54℃; the melting point of paraffin wax No. 56 is 54-58℃; the melting point of paraffin wax No. 58 is 56-60℃; and the melting point of paraffin wax No. 60 is 58-62℃).

[0078] During cable operation, the heat generated by the oxygen-free copper conductor 1 is transferred to the cross-linked polyethylene layer 4, and then introduced into the phase change medium 103 within the sealed cavity through the arc-shaped base plate 1046 of the shape memory metal heat-conducting element 104. When the temperature of the cross-linked polyethylene layer 4 exceeds the normal operating temperature threshold of the oxygen-free copper conductor 1, the phase change medium 103 undergoes a phase change, absorbs heat, and expands, increasing the pressure within the sealed cavity. This drives the arc-shaped waist tube 1047, which is concave in the middle, to expand and deform outward, thereby pushing the arc-shaped heat dissipation plate 1045 towards the second thermally conductive colloid layer 6. When the arc-shaped heat dissipation plate 1045 comes into contact with the second thermally conductive colloid layer 6, it undergoes slight deformation under the continuous action of expansion force. Simultaneously, the second thermally conductive colloid layer 6 also undergoes adaptive deformation, resulting in a tight fit between the two. The effective thermal contact area is significantly increased, and heat is transferred through the arc-shaped base plate 1046, the arc-shaped waist tube 1047, and the arc-shaped waist tube 1046. The heat dissipation plate 1045 and the phase change medium 103 are quickly transferred to the second thermally conductive colloid layer 6 to achieve efficient heat dissipation. When the temperature of the cross-linked polyethylene layer 4 drops below the normal operating temperature threshold, the phase change medium 103 cools and contracts, the pressure inside the sealed cavity decreases, and the arc-shaped waist tube 1047 of the shape memory metal heat conductor 104 resets using its own shape memory effect, causing the arc-shaped heat dissipation plate 1045 to separate from the second thermally conductive colloid layer 6, reducing the effective thermal contact area and reducing internal heat loss. The filling strip 105 in the heat dissipation channel is attached to the outer wall of the shape memory metal heat conductor 104. On the one hand, it can fix the position of the shape memory metal heat conductor 104 to prevent it from shifting during deformation. On the other hand, it can assist in heat preservation, reduce heat loss through the gaps in the heat dissipation channel, and fill the gaps between the shape memory metal heat conductor 104 and the insulation strip, improving the overall structure.

[0079] The shape memory metal heat-conducting component 104 integrates the functions of heat receiving (arc-shaped base plate 1046), deformation driving (arc-shaped waist tube 1047), and heat transfer (arc-shaped heat dissipation plate 1045), eliminating the need for additional heat-conducting strips 101, resulting in a simpler structure and less space occupied in the heat dissipation channel.

[0080] The concave structure of the arc-shaped waist tube 1047 can generate a stable expansion driving force when the phase change medium 103 expands, ensuring that the arc-shaped heat dissipation plate 1045 moves smoothly, the contact and separation process is smooth, and the temperature control response is stable.

[0081] The arc-shaped heat dissipation plate 1045 is in direct contact with the second thermally conductive colloid layer 6, and the two deform synchronously, which can maximize the effective thermal contact area. At the same time, the shape memory metal thermal conductive component 104 has excellent overall thermal conductivity and low heat transfer loss.

[0082] The filler strip 105 can fix the position of the shape memory metal heat conductor 104, preventing it from loosening or shifting during repeated deformation. At the same time, it fills the gaps and improves the overall structure of the heat dissipation channel. Combined with the fixed connection between the arc-shaped base plate 1046 and the cross-linked polyethylene layer 4, it further improves the stability of the component.

[0083] The filler strip 105 can assist in heat preservation, reduce heat loss in low-temperature environments, and at the same time, it does not affect the heat dissipation efficiency in high-temperature environments. Together with the shape memory metal heat conductor 104, it can achieve better temperature control and is suitable for harsh regions with greater temperature variations.

[0084] In summary, although the structures of the three embodiments of the self-regulating temperature-conducting component 10 are different, they can all adaptively realize the intelligent temperature control function of high-temperature heat dissipation and low-temperature temperature locking according to the actual temperature of the cross-linked polyethylene layer 4. They can stably maintain the oxygen-free copper conductor 1 and the main insulation layer in a suitable operating temperature range, effectively avoid overheating and aging of the insulation layer or low-temperature embrittlement, and improve the operating stability and service life of the cable in high and low temperature alternating environments.

[0085] Meanwhile, when the cable experiences a short-term overload or short-circuit fault, the phase change medium 103 can absorb a large amount of heat and undergo violent phase change expansion in a very short time. On the one hand, it can achieve instantaneous strong heat dissipation by rapidly increasing the thermally conductive contact area, thus delaying the rapid rise in the insulation layer temperature. On the other hand, the volume expansion triggers the shape memory metal heat-conducting element 104 to open significantly, forming an emergency heat dissipation channel. Under the instantaneous high temperature generated by the large current of the short circuit, it provides short-term thermal buffer protection for the cable, reducing the risk of thermal breakdown, scorching, or structural failure of the cross-linked polyethylene layer 4 due to instantaneous overheating, and further improving the safety of cable operation. It should be noted that the phase change medium 103 only provides short-term thermal buffer and does not replace the cable overload protection device.

[0086] In summary, this cable achieves purely mechanical adaptive temperature control solely through the phase change medium 103 and the shape memory metal heat-conducting component 104. It can achieve bidirectional regulation of high-temperature heat dissipation and low-temperature temperature locking without any power supply or electronic control device, breaking through the traditional single-temperature control mode of cables. Simultaneously, during the stranding process of the oxygen-free copper conductor 1, silicone gel is injected and co-extruded, allowing the gel to fully fill the stranding gaps, achieving integrated heat conduction, sealing, and buffering, significantly improving the interface electric field distribution and heat dissipation conditions of the oxygen-free copper conductor 1. The insulation layer 5 uses multiple insulation strips arranged circumferentially, providing insulation while reserving controllable heat dissipation channels and also ensuring temperature locking. To meet the requirements of efficient heat dissipation, the shape memory metal thermal conductive element 104, together with the thermal insulation strip and the cross-linked polyethylene layer 4, forms a multi-point fixed structure, which is stable and does not shift during deformation, requiring no additional auxiliary parts, and the structure is simple and reliable; the second thermally conductive colloid layer 6 is integrally formed with the embedded heat dissipation strip 61, and the contact interface is adaptively fitted by relying on the flexibility of the colloid, which greatly increases the effective heat conduction area; the double-layer organosilicon gel and the water-blocking layer 7 work together to form a full-section sealing system, which can effectively prevent moisture intrusion and compensate for the difference in thermal expansion and contraction between layers; in addition, the phase change medium 103 can provide instantaneous thermal buffer when the cable is overloaded or short-circuited, further improving the safety margin of the insulation layer.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A water-blocking medium- and high-voltage power cable, comprising an oxygen-free copper conductor (1), characterized in that, Also includes: The oxygen-free copper conductor (1) is sequentially covered and fixed from the inside out with a first thermally conductive colloid layer (2), a conductor shielding layer (3), a cross-linked polyethylene layer (4), a heat insulation layer (5), a second thermally conductive colloid layer (6), a water-blocking layer (7), an armor layer (8), and an outer jacket (9). The heat insulation layer (5) is composed of multiple heat insulation strips, which are distributed in a circular pattern on the outside of the cross-linked polyethylene layer (4). A heat dissipation channel is formed between two adjacent heat insulation strips, and a self-regulating temperature conduction component (10) is provided in the heat dissipation channel. The self-regulating temperature-conducting component (10) adjusts the effective thermal contact area between itself and the second thermally conductive colloid layer (6) according to the temperature change of the cross-linked polyethylene layer (4); When the temperature of the cross-linked polyethylene layer (4) exceeds the normal operating temperature threshold of the oxygen-free copper conductor (1), the effective thermal contact area between the self-regulating temperature-conducting component (10) and the second thermally conductive colloid layer (6) increases. When the temperature of the cross-linked polyethylene layer (4) is lower than the normal operating temperature threshold of the oxygen-free copper conductor (1), the effective thermal contact area between the self-regulating temperature-conducting component (10) and the second thermally conductive colloid layer (6) is reduced. The self-regulating temperature conduction component (10) includes a heat conduction strip (101) disposed in the heat dissipation channel and a memory metal heat conduction element (104) coupled to the heat conduction strip (101). A sealed cavity is provided in the heat conduction strip (101), and the sealed cavity is filled with a phase change medium (103). The phase change temperature range of the phase change medium (103) is within the normal operating temperature threshold range of the oxygen-free copper conductor (1). When the phase change medium (103) undergoes phase change and heat absorption expansion, the shape memory metal heat-conducting element (104) is driven by the force generated by the expansion to deform or displace, increasing the effective heat-conducting contact area between it and the second heat-conducting colloid layer (6). When the phase change medium (103) cools and shrinks, the shape memory metal thermal conductive element (104) resets itself using its own shape memory effect, reducing the effective thermal contact area with the second thermal conductive colloid layer (6).

2. The water-blocking medium and high voltage power cable according to claim 1, characterized in that, The heat-conducting strip (101) is fixedly connected to the cross-linked polyethylene layer (4). The heat-conducting strip (101) has a rectangular cross-section, and the side of the rectangle is provided with an inwardly recessed sidewall (102).

3. A water-blocking medium- and high-voltage power cable according to claim 2, characterized in that, The shape memory metal heat-conducting component (104) includes a heat-conducting plate (1041), which has a peak-valley structure. Both ends of the heat-conducting plate (1041) are fixedly installed with plug-in plates (1042), which are fixedly connected to the heat insulation strip. When the phase change medium (103) absorbs heat and expands, the heat-conducting strip (101) drives the heat-conducting plate (1041) to contact the second heat-conducting colloid layer (6), and at the same time the plug plate (1042) undergoes elastic deformation. When the phase change medium (103) cools and shrinks, the plug plate (1042) uses its own shape memory effect to drive the heat conduction plate (1041) to reset.

4. A water-blocking medium- and high-voltage power cable according to claim 3, characterized in that, The inner ring of the second thermally conductive colloid layer (6) is provided with an integrally formed embedded heat dissipation strip (61), and the side of the embedded heat dissipation strip (61) facing the heat dissipation plate (1041) is flat. When the phase change medium (103) absorbs heat and expands, the heat-conducting plate (1041) comes into contact with the embedded heat dissipation strip (61), and the heat-conducting plate (1041) drives the embedded heat dissipation strip (61) to deform, increasing the effective heat-conducting contact area between the heat-conducting plate (1041) and the embedded heat dissipation strip (61).

5. A water-blocking medium- and high-voltage power cable according to claim 1, characterized in that, The shape memory metal heat-conducting component (104) is composed of a heat-dissipating arc plate (1044) and a heat-absorbing arc plate arranged symmetrically. A fixed base plate (1043) is fixedly installed on the heat-absorbing arc plate. The fixed base plate (1043) is fixedly connected to the heat-conducting strip (101). The heat-conducting strip (101) is fixedly connected to the cross-linked polyethylene layer (4).

6. A water-blocking medium- and high-voltage power cable according to claim 5, characterized in that, The inner ring of the second thermally conductive colloid layer (6) is provided with an integrally formed embedded heat dissipation strip (61), and the side of the embedded heat dissipation strip (61) facing the heat dissipation arc plate (1044) is a raised arc surface; When the phase change medium (103) absorbs heat and expands, the heat dissipation arc plate (1044) abuts against the raised arc surface of the embedded heat dissipation strip (61). The heat dissipation arc plate (1044) drives the embedded heat dissipation strip (61) to deform and increase the effective thermal contact area between it and the heat dissipation arc plate (1044).

7. A water-blocking medium- and high-voltage power cable, comprising an oxygen-free copper conductor (1), characterized in that, Also includes: The oxygen-free copper conductor (1) is sequentially covered and fixed from the inside out with a first thermally conductive colloid layer (2), a conductor shielding layer (3), a cross-linked polyethylene layer (4), a heat insulation layer (5), a second thermally conductive colloid layer (6), a water-blocking layer (7), an armor layer (8), and an outer jacket (9). The heat insulation layer (5) is composed of multiple heat insulation strips, which are distributed in a circular pattern on the outside of the cross-linked polyethylene layer (4). A heat dissipation channel is formed between two adjacent heat insulation strips, and a self-regulating temperature conduction component (10) is provided in the heat dissipation channel. The self-regulating temperature-conducting component (10) adjusts the effective thermal contact area between itself and the second thermally conductive colloid layer (6) according to the temperature change of the cross-linked polyethylene layer (4); When the temperature of the cross-linked polyethylene layer (4) exceeds the normal operating temperature threshold of the oxygen-free copper conductor (1), the effective thermal contact area between the self-regulating temperature-conducting component (10) and the second thermally conductive colloid layer (6) increases. When the temperature of the cross-linked polyethylene layer (4) is lower than the normal operating temperature threshold of the oxygen-free copper conductor (1), the effective thermal contact area between the self-regulating temperature-conducting component (10) and the second thermally conductive colloid layer (6) is reduced. The self-regulating temperature conduction component (10) includes a shape memory metal heat conductor (104) disposed in the heat dissipation channel. One end of the shape memory metal heat conductor (104) is fixedly connected to the outer ring of the cross-linked polyethylene layer (4). A sealed cavity is provided inside the shape memory metal heat conductor (104), and the sealed cavity is filled with a phase change medium (103).

8. A water-blocking medium- and high-voltage power cable according to claim 7, characterized in that, The shape memory metal heat-conducting component (104) includes an arc-shaped base plate (1046) fixedly connected to the cross-linked polyethylene layer (4), an arc-shaped waist tube (1047) with a central inward concavity is fixedly installed on the arc-shaped base plate (1046), and an arc-shaped heat dissipation plate (1045) is fixedly installed at the other end of the arc-shaped waist tube (1047). When the phase change medium (103) absorbs heat and expands, the arc-shaped waist tube (1047) drives the arc-shaped heat dissipation plate (1045) to move towards the second thermally conductive colloid layer (6). When the arc-shaped heat dissipation plate (1045) comes into contact with the second thermally conductive colloid layer (6), the arc-shaped heat dissipation plate (1045) and the second thermally conductive colloid layer (6) simultaneously deform to increase the effective thermal contact area between the arc-shaped heat dissipation plate (1045) and the second thermally conductive colloid layer (6).

9. A water-blocking medium- and high-voltage power cable according to claim 8, characterized in that, A filler strip (105) is provided in the heat dissipation channel, and the filler strip (105) is attached to the outer wall of the shape memory metal heat conductor (104).

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