110kv high voltage polypropylene power cable

Abstract

This invention discloses a 110kV high-voltage polypropylene power cable, relating to the field of power cable technology. It includes an outer sheath, inside which a conductor is installed. A cable core sleeve is fitted around the outside of the conductor. A shielding sleeve is embedded in the outer wall of the cable core sleeve. An inner spacer sleeve is installed inside the outer sheath. A plurality of heat-conducting blocks are evenly and equidistantly installed on the outer wall of the inner spacer sleeve. A binding sleeve is fitted around the outer side of the inner spacer sleeve, and the binding sleeve is filled with a water-absorbing agent. This invention can achieve bidirectional limiting and locking protection of the cable's internal and external components, providing multiple internal supports, effectively balancing the internal stress stability of the cable during use, effectively improving the interface compatibility between various internal structures, effectively compensating for the interface air gaps generated by polypropylene heat shrinkage, achieving dual containment of water trees and electrical trees, structurally optimizing its mechanical properties, improving the stability of its electrical insulation performance, and increasing its effective service life.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, specifically a 110kV high-voltage polypropylene power cable. Background Technology

[0002] Cross-linked polyethylene (XLPE) cables have long been the mainstream choice for 110kV voltage level power transmission. However, XLPE cables have problems such as non-recyclability and high production energy consumption. With the increasing environmental protection requirements and the growing demand for power grid reliability, the development of new environmentally friendly and high-performance cable insulation materials has become an industry trend. 110kV high-voltage polypropylene power cables represent a major technological breakthrough in my country's power transmission field in recent years. Their core advantages are reflected in three aspects: material innovation, improved production efficiency, and performance optimization.

[0003] However, the inherent material properties of polypropylene make current polypropylene power cables less effective at protecting them. Due to insufficient mechanical strength, the cables are prone to damage due to external environmental stress. Furthermore, the poor interfacial compatibility between polypropylene and the internal structure of the cable, coupled with differences in thermal shrinkage rates, can easily lead to interfacial air gaps between the cable and the internal structure. As a result, water trees and electrical trees are easily generated during cable use, causing the cable insulation performance to fail and accelerating cable aging. Summary of the Invention

[0004] This invention provides a 110kV high-voltage polypropylene power cable, which can effectively solve the problems mentioned in the background art. The inherent material properties of polypropylene make the protection effect of the cable poor. It is easy for the cable to be damaged too quickly due to insufficient mechanical strength and external environmental stress. Its poor interface compatibility with the internal structure of the cable makes it easy to form interface air gaps between it and the internal structure due to the difference in thermal shrinkage rate. As a result, the cable is prone to water treeing and electrical treeing during use, which leads to the failure of the cable insulation performance and accelerated cable aging.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a 110kV high-voltage polypropylene power cable, comprising an outer sheath, a conductor installed inside the outer sheath, a cable core sleeve sleeved on the outside of the conductor, a shielding sleeve embedded in the outer wall of the cable core sleeve, and a composite compensation mechanism installed on the outside of the shielding sleeve.

[0006] The composite compensation mechanism includes an inner sleeve;

[0007] An inner partition sleeve is installed on the inner side of the outer sheath. Several heat-conducting blocks are evenly installed on the outer wall of the inner partition sleeve at equal intervals. A binding sleeve is sleeved on the outer side of the inner partition sleeve. The binding sleeve is filled with a water-absorbing agent. A groove is provided on the outer wall of the binding sleeve at the position corresponding to the heat-conducting block. Several locking rings are evenly embedded in the outer wall of the outer sheath at equal intervals. Several strips are installed at equal angles along the circumferential direction on the side end face of the locking ring.

[0008] The outer side of the shielding sleeve is uniformly and evenly equipped with several ring frames. Several cable sleeves are installed at equal angles along the circumferential direction on the side end face of the ring frame. Cable strips are inserted inside the cable sleeves. Studs are installed at the ends of the cable strips. End caps are installed at the ends of the outer sheath. Slip rings are slidably installed on the side end face of the end cap. Several compression springs are installed at equal angles along the circumferential direction on one side end face of the slip ring. Nuts are installed at the ends of the studs by threads.

[0009] Preferably, a pad is fitted onto the outer wall of the shielding sleeve, a ring plate is installed in the middle of the inner wall of the ring frame, and concave and convex ring strips are snapped onto both end faces of the ring plate, and a ring groove is opened on the outer wall of the pad corresponding to the position of the ring plate.

[0010] Several pads are installed at equal angles along the circumference at the gap position of the ring frame on the outer side of the cable. The inner wall of the pads is symmetrically provided with grooves. An isolation ring is installed on the outer curved edge of the ring frame. A sealing gasket is installed on the inner wall of the end cap.

[0011] Preferably, the end cap side has a through hole at the position corresponding to the cable strip, the slip ring is connected to the end cap by a compression spring, the end cap is slidably connected to the stud, and the stud has a semi-threaded structure on the outside. The stud passes through the slip ring and is slidably connected to the slip ring.

[0012] Preferably, the inner spacer sleeve is filled with liquid thermally conductive silicone grease at the gap between the rings, the binding sleeve has an elastic mesh structure, and the absorbent is a highly absorbent resin powder.

[0013] Preferably, the ring frame and the pad sleeve are slidably connected, the ring plate is connected to the end face of the groove through concave and convex ring strips, the concave and convex ring strips are elastic elements, the concave and convex ring strips are in the shape of annular waves, a number of convex rings are evenly arranged at equal intervals on the inner wall of the pad sleeve, and the pad sleeve and the convex rings are sealed and fitted with the cable core sleeve, the pad and the groove are both arc-shaped, and the groove fits with the cable strip.

[0014] Preferably, the conductor is made of annealed soft copper layers tightly pressed into a circular strand, and the outer sheath is made of polypropylene nanocomposite material.

[0015] Preferably, an integrated connecting mechanism is installed at the end of the end cap;

[0016] The integrated connection mechanism includes a base plate;

[0017] A base plate is installed on one side of the end cap. A pressure tube is embedded in the middle of the side end face of the base plate. A hollow ring is installed in the middle of the outer curved surface of the pressure tube. A protective sleeve is installed on the outer curved surface of the base plate. A heat shrink tube is installed on the end face of the protective sleeve. A ring washer is symmetrically and slidably installed inside the hollow ring. Several pull rods are installed at equal angles along the circumferential direction on the side end face of the ring washer. A nut is installed at the end of the pull rod. A threaded opening is opened at the end of the stud. The nut and the stud are connected by a pull rope. Both ends of the pull rope are equipped with screw heads. Several through holes are opened at equal angles along the circumferential direction at both ends of the hollow ring.

[0018] An annular box is installed at the end of the end cap. A sliding pad is slidably installed inside the annular box. Several connecting rods are rotatably installed on the side end face of the sliding pad at equal angles along the circumferential direction. Connectors are installed at the ends of the connecting rods. Several guide holes are opened at equal angles along the circumferential direction on the end face of the annular box. Several connecting holes are opened at equal angles along the circumferential direction on the outer curved edge of the substrate.

[0019] The protective sleeve has symmetrically slidingly installed annular plugs inside. Several springs are installed at equal angles along the circumferential direction on the side end face of the annular plugs. A rib is provided inside the protective sleeve between two annular plugs. Several guide holes are opened at equal angles along the circumferential direction on the outer curved surface of the rib. A through hole is opened on the side end face of the substrate corresponding to the guide hole. A material injection valve is provided in the middle of the outer curved surface of the protective sleeve.

[0020] Preferably, the pull rod is slidably connected to the hollow ring, the nut and the screw opening are both fitted with the screw head, and the nut and the screw opening are both connected to the screw head by threads, and the pull rope is an elastic strip.

[0021] Preferably, the connecting rod is slidably connected to the ring box, the connector is connected to the connecting hole by a thread, and the position of the connecting rod is directly opposite the position of the connecting hole.

[0022] Preferably, the gap between the two annular plugs inside the casing is connected to the through hole through a guide hole, and the through hole, through opening and guide opening are all connected to the space outside the pressure tube.

[0023] Compared with the prior art, the advantages of the present invention are: the present invention has a scientific and reasonable structure and is safe and convenient to use;

[0024] 1. Equipped with a composite compensation mechanism, the outer layer features a two-way locking structure formed by the cooperation of an inner sleeve, heat-conducting block, binding sleeve, groove, locking ring, and strip. This provides double reinforcement protection for the outer sheath, both internally and externally. On one hand, it provides a stable and reliable limiting and locking force to the outer sheath. On the other hand, it can structurally compensate and optimize the mechanical properties of polypropylene, effectively enhancing its tear resistance and impact resistance. It can fully utilize the high expansion properties of the water absorbent, effectively adapting to the high thermal shrinkage rate of polypropylene, effectively filling the interface gaps caused by shrinkage differences, and effectively inhibiting the germination of electrical trees. Furthermore, it can effectively block the longitudinal migration of moisture, effectively preventing water tree aging caused by chronic water infiltration. While further ensuring its mechanical protection stability, it can effectively improve the insulation breakdown field strength, fully guarantee the insulation performance stability of the cable, and significantly extend the effective service life of the cable.

[0025] On the other hand, it can be used in conjunction with ring frames, cable sleeves, cable strips, studs, end caps, slip rings, compression springs, and nuts to form an internal support structure. Combined with the circumferential limiting effect of gaskets, grooves, isolation rings, and sealing gaskets, as well as the dynamic filling effect of thermally conductive silicone grease, a dual support mechanism can be formed. This not only buffers and protects against external tensile, compressive, and bending forces, but also conducts and distributes them along the cable's axial and circumferential directions. While improving the cable's resistance to external forces and enhancing its structural stability, it effectively balances internal cable stress and fully utilizes the thermal conductivity of the thermally conductive silicone grease to promote heat dissipation. It also makes the conductor and outer sheath more compact, filling the interface gap and effectively improving interface compatibility, balancing interface stress, and further ensuring its insulation performance. Simultaneously, it can be used in conjunction with heat-conducting blocks to achieve dual internal and external heat conduction for rapid heat dissipation. Furthermore, the elastic limiting effect of gaskets, ring plates, ring grooves, and concave-convex rings improves the fit between the outer sheath and conductor, achieving dual stress relief and further effectively strengthening the polypropylene outer sheath.

[0026] 2. An integrated connection mechanism is provided, which, through the cooperation of the base plate, crimp tube, hollow ring, protective sleeve and heat shrink tubing, can effectively form an end protection structure. This can improve the convenience of cable connection while effectively strengthening the connection reliability of the cable end. In addition, the synchronous linkage of the ring washer, pull rod, nut, screw, pull rope and screw head can transmit the tensile, compressive and bending stresses subjected to the cable during use. It can also cooperate with the ring box, sliding washer, connecting rod, connector and connection hole to achieve double limit and form a two-way interlocking mechanism. It can not only synchronously transmit the external tensile, compressive and bending stresses subjected to the cable body, balance the stress stability between cables, and further improve the cable's resistance to environmental stress cracking, but also convert tensile, compressive and bending stresses into connection stresses between cables, improving the connection stability between cables.

[0027] On the other hand, it can be combined with ring plugs, springs, and ribs to form an end-load-bearing buffer structure, which can effectively maintain the internal stress stability of the cable connection. It can also be combined with a composite compensation mechanism to form a coordinated load-bearing mechanism inside and between cables. While ensuring the internal density and stability of the cable, it can provide a more sufficient load-bearing buffer gap for the cable, and at the same time provide a more reliable sealing and filling space for the cable connection. It can effectively utilize the fluidity and thermal conductivity of the insulating oil to promote rapid heat dissipation at the joint. In addition, the composite compensation mechanism enhances the heat exchange performance of the cable body, which can effectively enhance the thermal stability of the cable during use and further improve the insulation performance of the cable. Through the combination of guide holes, through holes, and injection valves, it can realize the rapid injection and flow of insulating oil, and improve the stability and smoothness of pressure transmission, ensuring the stability of cable use.

[0028] In summary, this cable achieves multiple reinforcements to the polypropylene sheath. It fully utilizes the high temperature resistance, low dielectric loss, and recyclability of polypropylene material, fundamentally addressing the industry pain points of traditional cables' non-recyclability and high carbon footprint. Simultaneously, it provides bidirectional limiting and locking protection both inside and outside the cable, offering multiple internal supports to effectively balance internal stress stability during use. This effectively improves the interface compatibility between various internal structures, effectively compensates for interface gaps caused by polypropylene heat shrinkage, and achieves dual containment of water and electrical trees. Structurally, it optimizes the cable's mechanical properties, enhances the stability of its electrical insulation performance, and increases its effective service life. Attached Figure Description

[0029] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0030] In the attached diagram:

[0031] Figure 1 This is a schematic diagram of the structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the conductor mounting structure of the present invention;

[0033] Figure 3 This is a schematic diagram of the composite compensation mechanism of the present invention;

[0034] Figure 4 This is a schematic diagram of the restraint sleeve installation structure of the present invention;

[0035] Figure 5 This is a schematic diagram of the heat-conducting block installation structure of the present invention;

[0036] Figure 6 This is a partial exploded view of the present invention;

[0037] Figure 7 This is a schematic diagram of the end cap mounting structure of the present invention;

[0038] Figure 8 This is a schematic diagram of the ring box mounting structure of the present invention;

[0039] Figure 9 This is a schematic diagram of the integrated connection mechanism structure of the present invention;

[0040] Figure 10 This is a schematic diagram of the hollow ring mounting structure of the present invention;

[0041] The diagram labels are: 1. Outer sheath; 11. Conductor; 12. Cable core sleeve; 13. Shielding sleeve;

[0042] 20. Composite compensation mechanism; 201. Inner spacer; 202. Heat-conducting block; 203. Restraint sleeve; 204. Groove; 205. Water absorbent; 206. Locking ring; 207. Strip; 208. Ring frame; 209. Cable sleeve; 210. Cable strip; 211. Stud; 212. End cap; 213. Slip ring; 214. Compression spring; 215. Nut; 216. Washer sleeve; 217. Ring plate; 218. Ring groove; 219. Concave and convex ring strips; 220. Gasket; 221. Groove; 222. Isolation ring; 223. Sealing gasket;

[0043] 21. Perforation; 22. Raised ring;

[0044] 30. Integrated connecting mechanism; 301. Base plate; 302. Press-fit tube; 303. Hollow ring; 304. Protective sleeve; 305. Heat shrink tubing; 306. Ring washer; 307. Pull rod; 308. Nut; 309. Threaded end; 310. Pull rope; 311. Thread head; 312. Through port; 313. Ring box; 314. Sliding pad; 315. Connecting rod; 316. Connector; 317. Connecting hole; 318. Ring plug; 319. Spring; 320. Raised rib; 321. Guide hole; 322. Through hole; 323. Injection valve; 324. Guide port. Detailed Implementation

[0045] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0046] Example: Figure 1-10As shown, the present invention provides a technical solution: a 110kV high-voltage polypropylene power cable, including an outer sheath 1, a conductor 11 installed inside the outer sheath 1, the conductor 11 being made of annealed soft copper layered tightly pressed circular stranding, the outer sheath 1 being made of polypropylene nanocomposite material to improve the environmental friendliness and transmission effect of the cable, a cable core sleeve 12 being sleeved on the outside of the conductor 11, a shielding sleeve 13 being embedded in the outer wall of the cable core sleeve 12, and a composite compensation mechanism 20 being installed on the outside of the shielding sleeve 13;

[0047] The composite compensation mechanism 20 includes an inner sleeve 201;

[0048] An inner spacer 201 is installed on the inner side of the outer sheath 1. Several heat-conducting blocks 202 are evenly installed on the outer wall of the inner spacer 201 at equal intervals. A binding sleeve 203 is sleeved on the outer side of the inner spacer 201. The binding sleeve 203 is filled with a water-absorbing agent 205. A groove 204 is provided on the outer wall of the binding sleeve 203 at the position corresponding to the heat-conducting block 202. Several locking rings 206 are evenly embedded in the outer wall of the outer sheath 1 at equal intervals. Several strips 207 are installed at equal angles along the circumferential direction on the side end face of the locking rings 206.

[0049] A number of ring frames 208 are evenly and equidistantly installed on the outer side of the shielding sleeve 13. The inner spacer 201 is filled with liquid thermally conductive silicone grease at the gaps between the ring frames 208. The binding sleeve 203 is an elastic mesh structure. The water absorbent 205 is a highly absorbent resin powder to improve waterproofness and interface compatibility. A number of cable sleeves 209 are installed at equal angles along the circumferential direction on the side end face of the ring frame 208. Cable strips 210 are inserted inside the cable sleeves 209. Studs 211 are installed at the ends of the cable strips 210. End caps 212 are installed at the ends of the outer sheath 1. Slip rings 213 are slidably installed on the side end face of the end caps 212.

[0050] Among them, the heat-conducting block 202 and the liquid thermal grease form a multi-level heat conduction path from the conductor 11 to the outer sheath 1, which can quickly dissipate the heat generated during operation and improve the overall heat dissipation performance and thermal stability.

[0051] Several compression springs 214 are installed at equal angles along the circumference on one end face of the slip ring 213. A through hole 21 is opened on the end face of the end cap 212 at the position corresponding to the cable 210. The slip ring 213 is connected to the end cap 212 through the compression springs 214. The end cap 212 is slidably connected to the stud 211, and the stud 211 has a semi-threaded structure on the outside. The stud 211 passes through the slip ring 213 and is slidably connected to the slip ring 213 to provide internal stress relief support and protection. A nut 215 is installed at the end of the stud 211 through the thread.

[0052] The outer wall of the shielding sleeve 13 is fitted with a pad 216, and the inner wall of the ring frame 208 is fitted with a ring plate 217 in the middle. Both ends of the ring plate 217 are fitted with concave and convex ring strips 219. The outer wall of the pad 216 is provided with a ring groove 218 corresponding to the position of the ring plate 217.

[0053] Several pads 220 are installed at equal angles along the circumference at the gap position of the ring frame 208 on the outer side of the cable strip 210. The inner wall of the pads 220 is symmetrically provided with grooves 221. The ring frame 208 is slidably connected to the pad sleeve 216. The ring plate 217 is connected to the end face of the groove 221 through the concave and convex ring strips 219. The concave and convex ring strips 219 are elastic elements and are in the shape of a ring wave. Several convex rings 22 are evenly provided at equal intervals on the inner wall of the pad sleeve 216. The pad sleeve 216 and the convex rings 22 are sealed and fitted with the cable core sleeve 12. The pads 220 and the grooves 221 are both arc-shaped, and the grooves 221 fit with the cable strip 210 to improve the compactness and stability of the internal structure. An isolation ring 222 is installed on the outer curved edge of the ring frame 208, and a sealing gasket 223 is installed on the inner wall of the end cap 212.

[0054] An integrated connecting mechanism 30 is installed at the end of the end cap 212;

[0055] The integrated connection mechanism 30 includes a substrate 301;

[0056] A base plate 301 is mounted on one side of the end cap 212. A crimping tube 302 is embedded in the middle of the side end face of the base plate 301. A hollow ring 303 is mounted in the middle of the outer curved surface of the crimping tube 302. A protective sleeve 304 is mounted on the outer curved surface of the base plate 301. A heat shrink tubing 305 is mounted on the end face of the protective sleeve 304. A ring washer 306 is symmetrically slidably mounted inside the hollow ring 303. Several pull rods 307 are mounted at equal angles along the circumferential direction on the side end face of the ring washer 306. Nuts 308 are mounted on the ends of the pull rods 307. A stud 21 1. A screw opening 309 is provided at one end. The nut 308 and the stud 211 are connected by a pull rope 310. Both ends of the pull rope 310 are equipped with screw heads 311. The pull rod 307 is slidably connected to the hollow ring 303. The nut 308 and the screw opening 309 are both fitted with the screw head 311. The nut 308 and the screw opening 309 are both connected to the screw head 311 by threads. The pull rope 310 is an elastic strip for linkage transmission. Both ends of the hollow ring 303 are provided with several through openings 312 at equal angles along the circumferential direction.

[0057] An annular box 313 is installed at the end of the end cap 212. A sliding pad 314 is slidably installed inside the annular box 313. Several connecting rods 315 are rotatably installed on the side end face of the sliding pad 314 at equal angles along the circumferential direction. A connector 316 is installed at the end of the connecting rod 315. Several guide holes 324 are opened at equal angles along the circumferential direction on the end face of the annular box 313. Several connecting holes 317 are opened at equal angles along the circumferential direction on the outer curved edge of the substrate 301. The connecting rods 315 are slidably connected to the annular box 313. The connector 316 is connected to the connecting hole 317 by threads. The position of the connecting rod 315 is directly opposite to the position of the connecting hole 317 to improve the connection stability.

[0058] Inside the casing 304, annular plugs 318 are symmetrically slidably installed. Several springs 319 are installed at equal angles along the circumferential direction on the side end face of the annular plugs 318. A rib 320 is provided inside the casing 304 between two annular plugs 318. Several guide holes 321 are opened at equal angles along the circumferential direction on the outer curved surface of the rib 320. A through hole 322 is opened on the side end face of the base plate 301 at the corresponding position of the guide hole 321. The gap between the two annular plugs 318 inside the casing 304 is connected to the through hole 322 through the guide hole 321. The through hole 322, the through port 312, and the guide port 324 are all connected to the outer space of the pressure pipe 302 to improve the smoothness of transmission and balance the internal pressure. A filling valve 323 is provided in the middle of the outer curved surface of the casing 304. The filling valve 323 is equipped with a one-way check valve structure to prevent the insulating oil from flowing back or the air bubbles from being drawn back under pressure changes, ensuring the safety and reliability of the injection process.

[0059] The working principle and usage process of this invention: When using this 110kV high-voltage polypropylene power cable, firstly, according to the total length requirement of the cable in actual use, select the appropriate number of cables according to the length of a single cable. After the cable is pulled and transported to the installation position, the cables are connected in sequence through the integrated connecting mechanism 30. After connecting the cable ends to the corresponding external equipment, it can be put into formal use.

[0060] Before connecting the cable, the nut 215 can be rotated according to the actual usage scenario. Under the elastic limiting action of the compression spring 214, the slip ring 213 will provide stable support to the nut 215. Then, during the rotation of the nut 215, the stud 211 is displaced by the thread, and the cable 210 is pulled by the stud 211, so that the cable 210 is tightened. Under the limiting of the groove 221, each pad 220 will also be squeezed by the cable 210 to more stably press against the inner spacer 201, giving it elastic support. It also cooperates with the heat-conducting block 202 and the binding sleeve 203 to give the outer sheath 1 sufficient elastic support.

[0061] During the aforementioned process of rotating the nut 215, while the cable 210 is subjected to elastic tension, it will also pull the nut 215 in the opposite direction through the stud 211. Under the compression of the nut 215, the slip ring 213 will compress the spring 214, so that the compressive force on the spring 214 and the elastic tension force on the cable 210 are dynamically balanced. By rotating the nut 215, the initial compression of the spring 214 can be adjusted, that is, the initial elastic support force it gives to the slip ring 213, and the tension force on the cable 210 can be synchronously limited, adjusting the tension force during its operation, so as to balance its bending flexibility, tensile strength and buffering and unloading capacity according to actual needs.

[0062] The aforementioned adjustments are assumed to have been completed and calibrated at the time of cable delivery. Therefore, during the installation process, adjustments are only required when there are specific requirements for the cable's bending flexibility, tensile strength, and buffering capacity. If there are no special requirements, the aforementioned adjustment process can be ignored and skipped, and the next step of cable connection work can be carried out directly.

[0063] When connecting cables, first, the crimping tube 302 is clamped onto the end of the conductor 11 of the cable to be connected, and the crimping tube 302 is stably crimped to the end of the conductor 11 using an external crimping device. Then, the screw heads 311 at both ends of the pull rope 310 are screwed into the screw holes 309 at the ends of the nuts 308 and studs 211, respectively. Each nut 308 and stud 211 is connected in series. Then, the connecting rod 315 is rotated to screw the connector 316 into the connecting hole 317, and the heat shrink tubing 305 is clamped onto the outside of the cable.

[0064] It should be noted that, by default, one end of the cable is already connected and fixed with the integrated connection mechanism 30. During construction, it is only necessary to connect and fix the integrated connection mechanism 30 to the end of the adjacent cable that does not have the integrated connection mechanism 30 installed, through the aforementioned steps. After that, use an external heating device to heat the heat shrink tubing 305 on both sides of the protective sleeve 304, so that it shrinks and hugs the outer sheath 1 of the cable on both sides, thus completing the initial connection.

[0065] Then, insulating oil is injected into the casing 304 through the injection valve 323, filling the gap between the two annular plugs 318. With the connection of the guide hole 321 and the through hole 322, the insulating oil will pass through the guide hole 321 and the through hole 322, filling the space outside the crimping tube 302. During the use of the cable, it enhances the protection effect at the connection and provides auxiliary insulation, cooling and arc extinguishing.

[0066] With the opening 312 connected, the insulating oil will enter the hollow ring 303 through the opening 312. Under its compression, the ring washer 306 will drag the pull rod 307 to slide along the hollow ring 303. Under the limit of the nut 308, the pull rope 310 will be tightened accordingly, and will further drag the cable 210 through the stud 211 to compensate for the elastic support force provided by the compression spring 214.

[0067] Simultaneously, with the through hole 322 connected, insulating oil will pass through the through hole 322 and enter the ring box 313, forcing the sliding pad 314 to drag the connecting rod 315 under the pressure of the insulating oil. Under the limitation of the connector 316 and the connecting hole 317, the base plate 301 is dragged synchronously, further enhancing the connection stability between the composite compensation mechanism 20 and the cable end. Since the direction of the insulating oil squeezing the ring pad 306 is opposite to the direction of the insulating oil squeezing the sliding pad 314, and with the through hole 322 connected, the insulating oil will simultaneously squeeze the ring pad 306 and the sliding pad 314 on both sides, a hydraulic interlocking mechanism can be formed here.

[0068] Under the traction of the pull rope 310, the pressure of the insulating oil is further transmitted synchronously to the two side cables 210, balancing the tension of the cables 210 inside the cables on both sides. Under the transmission of the cables 210, the supporting force of each pad 220 is also balanced, and the elastic supporting force of the outer sheath 1 of the two adjacent cables is also balanced synchronously, thus achieving an equivalent integrated connection of the two cables and improving the stability and reliability of the connection between the cables.

[0069] It should be added here that, during the construction process, the insulating oil inside the injection valve 323 can be selected according to actual needs. In the aforementioned process, that is, under the default state, the injected insulating oil is a biodegradable plant ester insulating oil. At the same time, the external insulating shielding tape and sealing tape can be wrapped around the outside of the integrated connection mechanism 30 in sequence for use in conjunction with it, so as to further improve the insulation shielding performance and sealing performance of the connection.

[0070] The selected plant ester insulating oil has good thermal stability and low temperature fluidity, and is suitable for temperatures ranging from -40℃ to 120℃, which can meet the insulation and cooling requirements under 110kV high voltage operating conditions.

[0071] During the use of the cable, when the cable is subjected to external forces such as pulling, squeezing, and twisting, the cable 210 will be pulled synchronously under the limit of the end cap 212, slip ring 213 and nut 215. It will synchronously pull and drag each ring frame 208 through the cable sleeve 209, so that each concave and convex ring 219 will be squeezed synchronously, which will initially offset and buffer the external force. At the same time, each ring frame 208 will also synchronously squeeze the thermal grease in its gap. The thermal grease will further unload and buffer the external force, and in the transmission process of the thermal grease, the force will be transmitted and dispersed along the cable axis, so that the cable can obtain sufficient support force to resist the external pulling, squeezing and twisting forces.

[0072] When the pull rope 310 is activated, the pull rod 307 is simultaneously stressed, and the ring pad 306 is compressed and squeezed to form a pressure transmission closed loop, which causes the sliding pad 314 to be simultaneously lifted, enhancing the interlocking stability of the joint and simultaneously increasing the bidirectional interlocking force at the cable connection to ensure the stability of the joint. In conjunction with the compression spring 214, it provides bidirectional support to the cable strip 210. Conversely, when the cable connection is subjected to tension and compression, the squeezing force of the insulating oil will also be simultaneously transmitted to the cable strip 210 in both cables. Using the aforementioned mechanism, the external force is dispersed and resolved along the cable axis through the cable strip 210.

[0073] At the same time, the thermal grease will work with the pad 220 to support the inner spacer 201, forming a dual support mechanism. This will improve the support stability of the outer sheath 1, allowing it to obtain sufficient support to resist external forces. At the same time, it will make full use of the thermal conductivity of the thermal grease to promote heat dissipation and make the conductor 11 and the outer sheath 1 more compact, filling the interface gap and improving their interface compatibility.

[0074] Similarly, during the use of the cable, after external water vapor penetrates the outer sheath 1, it will be absorbed by the water absorbent 205, i.e., super absorbent resin powder, inside the binding sleeve 203. After absorbing water, the super absorbent resin powder will expand to form a gel, which will block the longitudinal migration of water. While improving waterproofness, it can also provide auxiliary elastic support, make up for the defect of high heat shrinkage rate of polypropylene, fully fill the interface gaps, absorb mechanical stress, and balance interface stress.

[0075] Simultaneously, it can cooperate with the circumferential mesh locking structure formed by the locking ring 206 and the strip 207 to provide bidirectional constraint to the outer sheath 1. In conjunction with the heat-conducting block 202, it can quickly dissipate heat and further improve the heat dissipation effect. With the dual support of the inner thermal conductive silicone grease and the pad 220, it can achieve multi-dimensional reinforcement of the outer sheath 1 and make up for the lack of mechanical strength of polypropylene material.

[0076] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A 110kV high-voltage polypropylene power cable, comprising an outer sheath (1), characterized in that: The outer sheath (1) has a conductor (11) installed inside, and a cable core sleeve (12) is sleeved on the outside of the conductor (11). A shielding sleeve (13) is embedded in the outer wall of the cable core sleeve (12), and a composite compensation mechanism (20) is installed on the outside of the shielding sleeve (13). The composite compensation mechanism (20) includes an inner sleeve (201); An inner partition sleeve (201) is installed on the inner side of the outer sheath (1). Several heat-conducting blocks (202) are evenly installed on the outer wall of the inner partition sleeve (201). A binding sleeve (203) is sleeved on the outer side of the inner partition sleeve (201). The binding sleeve (203) is filled with a water-absorbing agent (205). A groove (204) is provided on the outer wall of the binding sleeve (203) at the position corresponding to the heat-conducting block (202). Several locking rings (206) are evenly embedded in the outer wall of the outer sheath (1). Several strips (207) are installed at equal angles along the circumferential direction on the side end face of the locking ring (206). The shielding sleeve (13) is uniformly and evenly equipped with several ring frames (208) on its outer side. Several cable sleeves (209) are installed at equal angles along the circumferential direction on the side end face of the ring frame (208). Cable strips (210) are inserted inside the cable sleeves (209). Studs (211) are installed at the ends of the cable strips (210). End caps (212) are installed at the ends of the outer sheath (1). Slip rings (213) are slidably installed on the side end face of the end caps (212). Several compression springs (214) are installed at equal angles along the circumferential direction on one side end face of the slip rings (213). Nuts (215) are installed at the ends of the studs (211) through threads. An integrated connecting mechanism (30) is installed at the end of the end cap (212); The integrated connection mechanism (30) includes a base plate (301); A base plate (301) is mounted on one side of the end cap (212). A pressure tube (302) is embedded in the middle of the side end face of the base plate (301). A hollow ring (303) is mounted in the middle of the outer curved surface of the pressure tube (302). A protective sleeve (304) is mounted on the outer curved surface of the base plate (301). A heat shrink tubing (305) is mounted on the end face of the protective sleeve (304). A ring gasket (306) is symmetrically slidably mounted inside the hollow ring (303). 306) Several pull rods (307) are installed at equal angles along the circumferential direction on the side end face. Nuts (308) are installed at the ends of the pull rods (307). A screw hole (309) is opened at the end of the stud (211). The nut (308) and the stud (211) are connected by a pull rope (310). Both ends of the pull rope (310) are equipped with screw heads (311). Several through holes (312) are opened at equal angles along the circumferential direction on both ends of the hollow ring (303). An annular box (313) is installed at the end of the end cap (212). A sliding pad (314) is slidably installed inside the annular box (313). Several connecting rods (315) are rotatably installed on the side end face of the sliding pad (314) along the circumferential direction at equal angles. A connector (316) is installed at the end of the connecting rod (315). Several guide holes (324) are opened at equal angles along the circumferential direction on the end face of the annular box (313). Several connecting holes (317) are opened at equal angles along the circumferential direction on the outer curved edge of the substrate (301). The sleeve (304) is symmetrically and slidably installed with annular plugs (318). Several springs (319) are installed at equal angles along the circumferential direction on the side end face of the annular plugs (318). A rib (320) is provided inside the sleeve (304) between two annular plugs (318). Several guide holes (321) are opened at equal angles along the circumferential direction on the outer curved surface of the rib (320). A through hole (322) is opened on the side end face of the substrate (301) corresponding to the guide hole (321). A filling valve (323) is provided in the middle of the outer curved surface of the sleeve (304).

2. The 110kV high-voltage polypropylene power cable according to claim 1, characterized in that, The outer wall of the shielding sleeve (13) is fitted with a pad (216), and the middle of the inner wall of the ring frame (208) is fitted with a ring plate (217). The two end faces of the ring plate (217) are fitted with concave and convex ring strips (219). The outer wall of the pad (216) is provided with a ring groove (218) corresponding to the position of the ring plate (217). Several pads (220) are installed at equal angles along the circumference at the gap position of the ring frame (208) on the outer side of the cable (210). The inner wall of the pads (220) is symmetrically provided with grooves (221). An isolation ring (222) is installed on the outer curved edge of the ring frame (208). A sealing gasket (223) is installed on the inner wall of the end cap (212).

3. A 110kV high-voltage polypropylene power cable according to claim 1, characterized in that, The end cap (212) has a through hole (21) at the position corresponding to the cable (210) on its side end face. The slip ring (213) is connected to the end cap (212) through a compression spring (214). The end cap (212) is slidably connected to the stud (211), and the stud (211) has a semi-threaded structure on the outside. The stud (211) passes through the slip ring (213) and is slidably connected to the slip ring (213).

4. A 110kV high-voltage polypropylene power cable according to claim 1, characterized in that, The inner sleeve (201) is filled with liquid thermally conductive silicone grease at the gap position of the ring frame (208), the binding sleeve (203) is an elastic mesh structure, and the water absorbent (205) is a highly absorbent resin powder.

5. A 110kV high-voltage polypropylene power cable according to claim 2, characterized in that, The ring frame (208) is slidably connected to the pad (216). The ring plate (217) is connected to the end face of the groove (221) through the concave and convex ring strip (219). The concave and convex ring strip (219) is an elastic element. The concave and convex ring strip (219) is in the shape of annular waves. The inner wall of the pad (216) is evenly provided with several convex rings (22). The pad (216) and the convex rings (22) are sealed and fitted with the cable core sleeve (12). The pad (220) and the groove (221) are both arc-shaped. The groove (221) fits with the cable strip (210).

6. A 110kV high-voltage polypropylene power cable according to claim 1, characterized in that, The conductor (11) is made of annealed soft copper layers tightly pressed into a circular strand, and the outer sheath (1) is made of polypropylene nanocomposite material.

7. A 110kV high-voltage polypropylene power cable according to claim 1, characterized in that, The pull rod (307) is slidably connected to the hollow ring (303), the nut (308) and the screw opening (309) are both fitted with the screw head (311), and the nut (308) and the screw opening (309) are both connected to the screw head (311) by threads, and the pull rope (310) is an elastic strip.

8. A 110kV high-voltage polypropylene power cable according to claim 7, characterized in that, The connecting rod (315) is slidably connected to the ring box (313), and the connector (316) is connected to the connecting hole (317) by a thread, and the position of the connecting rod (315) is directly opposite to the position of the connecting hole (317).

9. A 110kV high-voltage polypropylene power cable according to claim 7, characterized in that, The gap between the two annular plugs (318) inside the sleeve (304) is connected to the through hole (322) through the guide hole (321). The through hole (322), the through port (312) and the guide port (324) are all connected to the outer space of the pressure pipe (302).

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