Method for assisting replacement of composite insulator string by heavy-load unmanned aerial vehicle

Abstract

The invention discloses a method for assisting replacement of a composite insulator string by a heavy-load unmanned aerial vehicle, and relates to the technical field of power transmission line maintenance of a power system. In the prior art, a heavy-load unmanned aerial vehicle does not participate in a high-altitude replacement operation link of an insulator chain, the replacement of the insulator chain depends on manpower, the workload is large, and the safety risk is high. The method comprises the following steps: preparing on the ground and mounting a wire tightening tool; the heavy-load unmanned aerial vehicle is transported and positioned to an iron tower operation point; after personnel on the tower connect the upper end of the wire tightening tool and the iron tower, the heavy-load unmanned aerial vehicle is controlled to descend slowly, the load borne by the wire tightening tool is safely transferred to the iron tower from a lifting rope of the heavy-load unmanned aerial vehicle, and then the heavy-load unmanned aerial vehicle is separated; connecting a wire side and replacing an insulator string; and finally, carrying out heavy-load unmanned aerial vehicle hoisting and mounting on the insulator chain. According to the invention, the heavy-load unmanned aerial vehicle is renovated from a transportation tool to an operation platform capable of executing aerial load transfer, so that the mechanization of the core link of aerial operation is realized, the physical load and the safety risk of operators are reduced, and the efficiency and the safety of ultra-high-voltage line maintenance are improved.

Description

Technical Field

[0001] This invention relates to the field of power system transmission line maintenance technology, and in particular to a method for replacing composite insulator strings with the assistance of heavy-duty UAVs. Background Technology

[0002] Currently, the replacement of composite insulator strings for ultra-high voltage / extra-high voltage transmission lines mainly relies on two operating modes: The first method is the traditional manual operation mode, which relies entirely on manpower for mountain transportation, high-altitude rope passing, and tower tensioning and replacement. This method is extremely labor-intensive, inefficient, severely constrained by terrain and environment, and carries high safety risks for high-altitude operations.

[0003] The second type is the heavy-duty drone-assisted hoisting mode that has emerged in recent years. It uses heavy-duty drones to solve the problem of transporting materials in mountainous terrain, hoisting insulator strings or tools to the tower. However, in this mode, the heavy-duty drones only play the role of "aerial couriers," separating after unloading. All subsequent core high-altitude operations such as tensioning, splicing, and load transfer still need to be completed by personnel on the tower using physical strength. This mode fails to fundamentally change the operation mode, reduce the burden on personnel, or achieve mechanization of the operation process.

[0004] Therefore, existing technologies suffer from drawbacks such as low automation in core high-altitude operations, waste of human resources, operational efficiency limited by personnel physical strength, and high safety risks in complex environments. Summary of the Invention

[0005] The technical problem to be solved and the technical task proposed by this invention is to improve and refine existing technical solutions, and to provide a method for replacing composite insulator strings with the assistance of heavy-duty drones. This method aims to achieve high-altitude assisted replacement of composite insulator strings using heavy-duty drones, significantly reducing the physical burden and safety risks on operators, and improving operational efficiency and safety. To this end, this invention adopts the following technical solution.

[0006] A method for replacing composite insulator strings with the assistance of a heavy-duty drone includes the following steps: 1) Ground preparation and mounting: Inspect and pre-assemble the tensioning tools and backup protective ropes on the ground, and mount the tensioning tools under the sling of the heavy-duty UAV. 2) Aerial transport and positioning: Control the heavy-duty UAV to fly to the side of the tower operation point and control it to land slowly so that the upper and lower connection points of the tensioning tool are basically flush with the construction holes at the tower end and the conductor end. 3) Wire tensioning system connection and load transfer: The tower workers connect the upper end of the wire tensioning tool to the construction hole at the tower end; then, the heavy-duty drone is slowly lowered to transfer the load on the wire tensioning tool from the hoisting rope to the tower; after confirming that the load transfer is stable, the wire tensioning tool is separated from the hoisting rope; the tower workers then connect the lower end of the wire tensioning tool to the conductor. 4) Insulator string replacement: The old insulator string is tied and fixed to the hoisting rope of the heavy-duty drone as a fall protection. Then, the tensioning tool is used to loosen the old insulator string to be replaced and remove it from the hardware. The heavy-duty drone is then slowly raised to apply force to the old insulator string. The heavy-duty drone lifts it off and transports it to the ground. Then, the heavy-duty drone is used to hoist the new insulator string to the work point. The tower workers install the new insulator string in place and remove its binding rope. Then, the tensioning tool is used to restore the conductor to a stressed state.

[0007] This method, through the above steps, especially step 3) of "tensioning system connection and load transfer", transforms heavy-duty UAVs from a single aerial transport tool into an "aerial work platform" capable of actively performing force conversion. It realizes the mechanization of the core link of high-altitude tensioning operations, enabling heavy-duty UAVs to accurately and stably complete the most physically demanding and risky load transfer tasks, thereby freeing workers from high-risk and high-intensity physical labor, fundamentally improving the inherent safety and efficiency of the operation, and providing a brand-new human-machine collaborative operation mode for power transmission line maintenance.

[0008] As a preferred technical means, the suspension rope configuration has two types: The lower end of the first type of suspension rope is equipped with a rabbit ear knot, which is used to hang tensioning tools and old or new insulator strings for the replacement of insulator strings on ultra-high voltage line towers. The second type of suspension rope has a rabbit ear knot at the lower end and a figure-eight knot above the rabbit ear knot. The rabbit ear knot is used to hang tensioning tools and old insulator strings, while the figure-eight knot is used to hang new insulator strings, which is for the replacement of insulator strings on ultra-high voltage line towers.

[0009] The specialized hoisting rope configuration scheme optimized for lines of different voltage levels achieves standardization of work tools and adaptability to different scenarios. By pre-setting different knot combinations for UHV and EHV lines, the hoisting rope is matched with the target operation type during the preparation stage. This reduces the time for on-site temporary adjustments and knotting, and lowers the risk of unreliable knots due to unfamiliarity with the operation. At the same time, it ensures that the heavy-duty UAV hoisting system has the best balance and stability when combining insulator strings of different weights and sizes with tools, thereby improving the professionalism, efficiency and safety of the operation from the tool level.

[0010] As a preferred technical means: when using a rabbit-ear knot on a suspension rope to hang a tensioning tool alone, the two upper connecting shackles at the upper end of the chain hoist and wire sleeve of the tensioning tool are respectively hung on the two hanging rings of the rabbit-ear knot; when using a suspension rope to hang an old insulator string or a new insulator string alone, the lower end of the suspension rope is connected to a short rope through a safety buckle, and the lower end of the short rope is tied to the insulator string; when using a suspension rope to hang both a tensioning tool and an old insulator string at the same time, the two upper connecting shackles at the upper end of the tensioning tool are connected to one hanging ring of the rabbit-ear knot at the lower end of the suspension rope, and the other hanging ring of the rabbit-ear knot is connected to a short rope through a safety buckle, and the lower end of the short rope is tied to the old insulator string.

[0011] This technical solution clarifies the usage of lifting ropes and short ropes, and defines the allocation logic of the two hanging rings of the rabbit ear knot. It avoids the risk of the hoisted objects getting tangled and colliding in the air, and allows the tensioning tools and insulator strings to be quickly untied and hung, with a firm and reliable hang. This greatly reduces the difficulty of operation and the probability of human error, and ensures the safety and reliability of the hoisting process.

[0012] As a preferred technical means: the upper end of the short rope is equipped with a figure-eight knot, which is connected to the safety buckle. The lower end of the short rope is equipped with a back buckle, which is used to bind the insulator string. The figure-eight knot at the upper end of the short rope is used to connect to the safety buckle. The figure-eight knot structure is firm and not easy to loosen, ensuring the connection strength with the main suspension rope system. The back buckle at the lower end is used to bind the insulator string. The back buckle method can tightly fit and lock onto the cylindrical insulator string core rod. The greater the force, the tighter the binding, effectively preventing slippage.

[0013] As a preferred technical means: In step 3), the tower workers connect and lock the upper connecting shackle on the tensioning tool to the construction hole at the end of the tower. They then operate the heavy-duty drone to descend slowly and at a constant speed of no more than 0.2 meters per second, so that the hoisting rope gradually loosens. This causes the connection between the upper connecting part of the tensioning tool and the construction hole of the tower to gradually be stressed and tightened until the tensioning tool and the conductor load it carries are completely borne by the tower.

[0014] This technical solution ensures that the load is transferred smoothly and without impact from the heavy-load drone to the tower. This avoids the damage that the dynamic impact load generated by the rapid descent may cause to the tower mounting points and connecting parts, and also prevents the heavy-load drone from becoming unstable or the connecting parts from becoming loose due to sudden changes in force.

[0015] As a preferred technical means: In step 2), the heavy-duty UAV maintains a safe distance of more than 10 meters from the tower structure when hovering, positioning, or flying. By setting and maintaining a minimum safe distance, the risk of collision between the heavy-duty UAV and the tower due to eddy currents, electromagnetic interference, or operational errors is effectively avoided, providing a basic safety guarantee for the entire operation.

[0016] As a preferred technical means: when the working tower is a double-circuit tower and the adjacent circuit is energized and it is necessary to carry out work near the energized circuit, during the descent process in step 2) and the hoisting process in step 4), guy ropes controlled by a dedicated person are set at each level of the crossarm of the tower. The guy ropes actively guide and constrain the swing path of the hoisting rope and the suspended object, so that they pass through the preset safety passage.

[0017] This technical solution addresses the critical safety challenge of heavy-duty drone rigging potentially colliding with nearby charged objects due to wind-induced drift in complex electrified environments. By actively intervening and controlling the movement, uncontrollable drift is transformed into a controlled path, greatly expanding the feasibility and safety of this method in high-risk scenarios such as live-line work.

[0018] As a preferred technical approach: when replacing the upper phase insulator string, the guy rope is installed at the ground wire crossarm; when replacing the middle phase insulator string, the guy rope is installed at both the upper phase crossarm and the ground wire crossarm; when replacing the lower phase insulator string, the guy rope is installed at the upper phase crossarm, the middle phase crossarm, and the ground wire crossarm. This provides standardized and differentiated guy rope configuration schemes for different working phases, forming a multi-layered, three-dimensional safety guidance channel from top to bottom. This ensures that safety measures are precisely matched with specific operational needs, guaranteeing absolute safety while avoiding resource waste.

[0019] As a preferred technical approach, when the work involves a V-shaped insulator string, the dismantling and installation of its two sub-strings should be carried out separately using different heavy-duty drone approach and lifting paths. Considering the complex spatial structure of the V-shaped string and the staggered positions of the two sub-strings, this differentiated path strategy avoids interference or entanglement between the lifting rope and the other sub-string or fittings, ensuring smooth and safe operation and demonstrating the method's good adaptability to special tower types.

[0020] As a preferred technical approach, the length L of the sling for the heavy-duty UAV needs to be pre-configured or verified to meet the following relationship: ;in, To ensure a safe distance between heavy-duty drones and towers, The vertical height difference between the work point conductor and the nearest obstacle point above the tower. The overall added value includes the length of the lashing point, operational margin, and environmental wind deflection compensation. It comprehensively considers safety distance, tower geometry, dynamic operational requirements, and environmental factors, fundamentally avoiding situations where heavy-duty drones are forced into dangerous distances or unable to complete operations due to insufficient rope length, thus improving the scientific nature of the initial planning and the success rate of on-site operations.

[0021] Beneficial effects: 1. By upgrading heavy-duty drones from "transportation tools" to "operation platforms" capable of "aerial load transfer", the most physically demanding and risky wire-tensioning system splicing operation has been mechanized, freeing high-altitude workers from heavy physical labor and transforming them into low-intensity confirmation and monitoring personnel, thus realizing an intelligent upgrade of the operation mode.

[0022] 2. Mechanized operations reduce reliance on manual labor and the time spent in high-intensity operations on the tower, significantly improving overall operational efficiency. Simultaneously, the precise and stable operation of heavy-duty drones reduces the risk of human error, and standardized processes minimize uncertainties, comprehensively enhancing operational safety.

[0023] 3. It significantly reduces the physical exertion of workers at height, allowing them to focus on technical decision-making and precise installation, thus enhancing the value of human resources; at the same time, it reduces the number of personnel required for a single operation, thereby lowering labor costs.

[0024] 4. The proposed standardized hoisting and safety control strategies for different voltage levels and tower types enable the method to be applied safely and efficiently in various complex line environments, solving the application bottleneck of traditional methods in complex terrain and energized conditions. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the binding of the ultra-high voltage wire tensioning tool of the present invention.

[0026] Figure 2 This is a schematic diagram of the binding of ultra-high voltage insulator strings according to the present invention.

[0027] Figure 3 This is a schematic diagram of the heavy-duty drone mounting rope of the present invention.

[0028] Figure 4 This is a schematic diagram of the ultra-high voltage wire tensioning tool and insulator string binding of the present invention.

[0029] Figure 5 This is a schematic diagram of the present invention.

[0030] Figure 6 This is a schematic diagram of the 1000kV double-circuit AC transmission tower type in Embodiment 1 of the present invention.

[0031] Figure 7 This is a schematic diagram of the 1000kV single-circuit AC transmission tower type in Embodiment 1 of the present invention.

[0032] Figure 8 This is a schematic diagram of a tower type in the operating condition of a 500kV double-circuit AC line in Embodiment 2 of the present invention.

[0033] Figure 9 This is a schematic diagram of the two towers in the operating condition of a 500kV double-circuit AC line in Embodiment 2 of the present invention.

[0034] Figure 10 This is a schematic diagram of the first tower type of the 500kV single-circuit AC line in Embodiment 2 of the present invention.

[0035] Figure 11 This is a schematic diagram of the second tower type of the 500kV single-circuit AC line in Embodiment 2 of the present invention.

[0036] In the diagram: 1. Heavy-duty drone; 2. Suspension rope; 3. Short rope; 4. Tensioning tool; 5. Safety buckle; 6. Old insulator string; 201. Rabbit ear knot; 202. Suspension rope figure-eight knot; 301. Short rope figure-eight knot; 302. Back buckle; 401. Upper connecting shackle; 402. Aluminum alloy hoist; 403. Wire sleeve; 404. Lifting point pulley; 405. Lower connecting shackle. Detailed Implementation

[0037] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Where specific techniques or conditions are not specified in the embodiments, they should be performed in accordance with the techniques or conditions described in the literature in the art or in accordance with the product manual.

[0038] Example 1: UHV Heavy-Duty UAV-Assisted Replacement of Composite Insulator Strings This embodiment provides a method for replacing composite insulator strings using a heavy-duty UAV assisted replacement, suitable for ultra-high voltage transmission lines. For example... Figure 1-3 As shown, the method specifically includes the following steps.

[0039] S1 ground preparation and mounting: Before operation, all equipment, including the heavy-duty drone 1, lifting rope 2, shackles, aluminum alloy hoist 402, wire sleeve 403, lifting point pulley 404, safety buckle 5, and backup protection system, must be inspected on the ground. In this embodiment, the backup protection system is a backup protection rope, which must be ensured to be intact. Subsequently, the tensioning tool 4 is pre-assembled. For example... Figure 1 and 3 As shown, the pre-assembled tensioning tool 4 mainly includes an aluminum alloy hoist 402, a wire sleeve 403, a lifting point pulley 404, an upper connecting shackle 401 connected to the upper end of the aluminum alloy hoist 402 and the upper end of the wire sleeve 403, and a lower connecting shackle 405 connected to the lower end of the lifting point pulley. Each hanging point at the upper end of the tensioning tool 4 is equipped with two upper connecting shackles 401, one of which is connected to the rabbit ear knot 201 of the lifting rope 2, and the other hangs down naturally.

[0040] S2 Aerial Transport and Positioning: Control the heavy-duty drone 1 to take off and fly to the side of the tower work point. During the flight, a sufficiently long hoisting rope 2 must be selected to ensure that the fuselage of the heavy-duty drone 1 maintains a safe distance of more than 10 meters from the tower structure, especially the ground wire crossarm. Monitor the operation through ground personnel observation or the heavy-duty drone's image transmission system, and slowly land the heavy-duty drone 1, making minor adjustments until the upper connecting shackle 401 of the tensioning tool 4 is basically aligned with the construction hole at the tower end, and the lower connecting shackle 405 is basically aligned with the construction hole at the conductor end.

[0041] S3 Wire Tensioning System Connection and Load Transfer: First, the tower workers reliably install an independent backup safety rope at a suitable position on the tower. Next, the tower workers connect and lock the naturally hanging upper connecting shackle 401 on the wire tensioning tool 4 to the construction hole at the tower end. After confirming a reliable connection, the heavy-duty drone 1 is lowered slowly and at a constant speed not exceeding 0.2 meters per second. This rate is designed to ensure a smooth load transfer and avoid impact. Through the controlled descent of the heavy-duty drone 1, its suspension rope 2 gradually loosens, thereby gradually tensioning the connection between the upper end of the wire tensioning tool 4 and the construction hole on the tower until the load is fully borne by the tower. After confirming a stable load transfer, the upper connecting shackle 401 of the wire tensioning tool 4 is removed from the lower end of the suspension rope 2, separating the heavy-duty drone 1 from the wire tensioning tool 4. The tower workers then connect the lower connecting shackle 405 on the conductor side of the wire tensioning tool 4 to the construction hole at the conductor end.

[0042] Replacement of S4 insulator strings: (e.g.) Figure 2 As shown, using short rope 3, the lower end is secured with a back-loop binding method using a back-loop buckle 302 to firmly bind the old insulator string 6. Finally, the short rope figure-eight knot 301 at the upper end of short rope 3 is attached to the rabbit ear knot 201 at the lower end of suspension rope 2 via a safety buckle 5. By operating the aluminum alloy hoist 402, the tensioning tool 4 is tightened, loosening the old insulator string 6 to be replaced, and then it is detached from the hardware at both ends. After the old insulator string 6 is detached from the hardware, the heavy-duty drone 1 is slowly raised, so that the old insulator string 6 bound to suspension rope 2 is under tension. After confirming that the binding is secure, the heavy-duty drone 1 is operated to transport the old insulator string 6 directly back to the ground site. For the installation of the new insulator string, the new composite insulator string is bound on the ground using the back-loop buckle 302 of short rope 3, and then the short rope figure-eight knot 301 at the upper end of short rope 3 is attached to the rabbit ear knot 201 at the lower end of suspension rope 2 via a safety buckle 5. The heavy-duty drone 1 is used to hoist the new insulator string to the crossarm at the work site. The drone 1 is slowly lowered to position the new insulator string. After the tower workers install the hardware at both ends of the new insulator string, the connection between the short rope 3 and the new insulator string is removed. Finally, the tensioning tool 4 is used to restore the conductor to its normal tension, completing the replacement.

[0043] When the working tower is a double-circuit tower and adjacent circuits are energized, requiring live-line work, to ensure safety during the landing and hoisting of insulator strings by the heavy-duty drone 1, guy ropes controlled by designated personnel must be installed at each level of the tower's crossarms. Specifically, when replacing the upper phase insulator string, the guy rope is installed at the ground wire crossarm; when replacing the middle phase insulator string, the guy rope is installed at both the upper phase and ground wire crossarms; when replacing the lower phase insulator string, the guy rope is installed at the upper phase, middle phase, and ground wire crossarms. The guy ropes can actively apply lateral tension, guiding and constraining the swing path of the hoisting rope 2 and the suspended object, forcing them to pass through the preset "safety channel," effectively avoiding contact with adjacent energized lines.

[0044] The length L of the sling for the heavy-duty drone 1 must satisfy the following relationship: .in, To ensure a safe distance between the heavy-duty drone and the tower, this embodiment uses 10 meters. The vertical height difference between the working point conductor and the upper ground wire crossarm needs to be determined according to the specific tower type. In this embodiment, it is assumed to be 15 meters. To provide comprehensive added value, including the length of the binding point, an operational margin typically ranging from 0.5 to 1 meter, and the length reserved to compensate for wind sway, in this embodiment, The overall added value includes the length of the lashing point (approximately 1 meter), the allowance for personnel operation on the tower (approximately 0.5 meters), and the wind deflection compensation estimated based on the on-site wind speed (e.g., approximately 2.5 meters for a wind speed of 5 m / s, based on experience). The total is approximately 4 meters, therefore the minimum required sling length L = 10 + 15 + 4 = 29 meters. This calculation ensures the safety and operability of the operation; in actual configuration, a standard sling slightly longer than this value will be selected. This calculation ensures that the heavy-duty drone can hover at a safe distance, while the hook can accurately deliver the load to the work point, leaving room for wind sway and fine-tuning.

[0045] This embodiment deeply integrates heavy-duty drones into the core operation of the tensioning system, upgrading it from a transportation tool into an aerial work platform capable of load transfer. This greatly reduces the physical burden on personnel on the tower and improves operational efficiency and safety.

[0046] The following are standardized heavy-duty UAV hoisting and safety control strategies for different tower types of UHV lines to ensure the universality and safety of operations.

[0047] like Figure 5 The image shows a ±800kV DC transmission tower type. This tower type is characterized by V-shaped insulator strings for the conductors, consisting of inner and outer strings. Heavy-duty UAV lifting strategies must adapt to this special structure.

[0048] The specific operation is as follows: In step S2, the heavy-duty drone 1 is used to hoist and install the pre-assembled tensioning tool 4 from the middle area of ​​the tower. In step S4, when replacing the insulator string, the operation must be carried out in a specific order: first, the tensioning tool is used to loosen the insulator string, then the inner insulator string is removed, and the heavy-duty drone 1 temporarily suspends and fixes it before hoisting it away; subsequently, the heavy-duty drone 1 is used to fly to the outside of the ground wire crossarm, and then the old outer insulator string is removed and hoisted away. When installing the new insulator string, the order is reversed: first install the outer string, then install the inner string. After completing the operation for one phase, the tensioning tool 4 is transferred to the next phase and the above process is repeated. Figure 5 The middle arrow indicates the direction of descent.

[0049] like Figure 6 The image shows a 1000kV double-circuit AC transmission tower, characterized by the conductor crossarm located inside the ground wire crossarm. The core safety risk lies in the possibility that, when the other circuit is energized, the hoisting rope 2 of the heavy-duty drone 1 may come into contact with a energized line due to wind swaying during ascent and descent. Therefore, strict safety control measures must be implemented during the descent of S2 and the hoisting of S4. Specifically, guy ropes controlled by designated personnel should be installed at each level of the tower's crossarms to actively guide and restrain the swing path of the hoisting rope 2 and the suspended load. Figure 6 The middle arrow indicates the direction of descent.

[0050] The specific configuration is as follows: when replacing the upper phase insulator string, the guy rope is set at the ground wire crossarm; when replacing the middle phase insulator string, the guy rope is set at the upper phase crossarm and the ground wire crossarm respectively; when replacing the lower phase insulator string, the guy rope is set at the upper phase crossarm, the middle phase crossarm and the ground wire crossarm respectively, thus forming a multi-level, three-dimensional safety guidance channel from top to bottom, and forcing the hoisting path to pass through the preset "safety channel".

[0051] like Figure 7 The image shows a 1000kV single-circuit AC transmission tower type. The relative positions of the ground wire crossarm and conductor crossarm vary in this type of tower. Flexible strategies are needed for heavy-duty drone lifting operations.

[0052] During stages S2 and S4, the hoisting of insulator strings requires flexible selection of the angle from the inside or outside of the ground wire crossarm, depending on the shielding condition, to find the optimal interference-free hoisting path. For the hoisting of tensioning tools 4, to facilitate installation at the center of the tower, they are typically lowered from the inside of the tower. Figure 7 The middle arrow indicates the direction of descent.

[0053] Example 2: UHV Heavy-Duty Unmanned Aerial Vehicle-Assisted Replacement of Composite Insulator Strings Unlike the previous embodiment, this embodiment optimizes the tool mounting and binding methods to suit the characteristics of ultra-high voltage lines.

[0054] In this embodiment, as Figure 4 As shown, during the ground preparation and mounting phase, the new composite insulator string and the pre-assembled tensioning tool 4 are simultaneously mounted on the sling 2 of the heavy-duty UAV 1. Specifically, the new composite insulator string is mounted using a figure-eight knot 202 on the sling. Because the figure-eight knot is simple to tie and becomes tighter as it is pulled under tension, it is very suitable for fixing cylindrical heavy objects such as insulator strings. Meanwhile, the pre-assembled tensioning tool 4 is hung on one loop of the rabbit ear knot 201, and the other loop is connected to the short rope 3 via the safety buckle 5. In this embodiment, the tensioning tool 4 includes a shackle, an aluminum alloy hoist 402, and a wire sleeve 403. The lower end of the aluminum alloy hoist 402 is provided with a lower connecting shackle 405. The upper end hook of the aluminum alloy hoist 402 is connected to two upper connecting shackles 401 via the wire sleeve 403. One of the upper connecting shackles 401 is hung on a loop of the rabbit ear knot 201 at the lower end of the hoisting rope 2, and the other upper connecting shackle 401 hangs down naturally. The other loop of the rabbit ear knot 201 is connected to the short rope 3 via the safety buckle 5.

[0055] During the insulator string replacement phase, the old insulator string 6 to be replaced is secured to the lower end of the short rope 3 using the back buckle 302. The short rope figure-eight knot 301 at the upper end of the short rope 3 is connected to the rabbit ear knot 201 at the lower end of the suspension rope 2 via the safety buckle 5. Then, the tensioning tool 4 is tightened by operating the aluminum alloy hoist 402, loosening the old insulator string 6, which is then detached from the hardware. The heavy-duty drone 1 is then slowly raised to apply force to the old insulator string 6. The heavy-duty drone is then slowly lowered to position the new insulator string at the crossarm. After the tower workers install the upper and lower ends of the new insulator string, it is detached from the figure-eight knot on the suspension rope 2. After the adjustment and climbing are completed, the old insulator string 6 is transported directly back to the site by the heavy-duty drone 1, completing the recycling of the old insulator string.

[0056] In addition, the operation of the air transport and positioning phase and the tensioning system coupling and load transfer phase is basically the same as in Example 1.

[0057] When the work object is a V-shaped insulator string, since the two sub-strings are spatially intersecting, different heavy-duty drones should be used for approach and hoisting during dismantling and installation to avoid interference between the hoisting rope 2 and the other sub-string or fittings. This embodiment also follows the core hoisting principles, safety distance requirements, and guy rope setting methods in Embodiment 1, ensuring safety and efficiency in ultra-high voltage line environments.

[0058] The following are standardized heavy-duty UAV hoisting and safety control strategies for different tower types of ultra-high voltage lines to ensure the universality and safety of operations.

[0059] The main tower types for 500kV double-circuit AC transmission lines include the following two operating conditions: like Figure 8 The diagram shows a tower type in working condition 1, characterized by a ground wire crossarm extending inwards, obstructing the path for descent from directly above the tower. In phases S2 and S4, the heavy-duty UAV 1 should fly to the outside of the tower, find an unobstructed vertical path, and slowly descend from the outside to hoist the insulator string or tools to the work point. Since the hoisting rope 2 hangs naturally outside the tower, posing no risk of interference with the tower body or internal structure, it is usually unnecessary to assign a dedicated person to control the direction of the guy ropes. Figure 8 The middle arrow indicates the direction of descent.

[0060] like Figure 9 The diagram shows a two-tower type under operating conditions, characterized by the conductor crossarm located inside the ground wire crossarm. Safety risks and control measures are similar to those of the 1000kV double-circuit line in Example 1. If both lines are shut down simultaneously, work can proceed normally. If they are not shut down simultaneously, dedicated personnel must be stationed at each level of crossarm to control the guy ropes. The configuration principle for the upper, middle, and lower phases, respectively, on different crossarms is the same as in Example 1, to form a safety passage. Figure 9 The middle arrow indicates the direction of descent.

[0061] like Figure 10 , 11 The image shows the tower types for a 500kV single-circuit AC line, including V-type series towers. These tower types have relatively simple tower head structures, and the working space is usually quite open. In stages S2 and S4, the basic descent method can be chosen to approach from the inside or outside, depending on the available space. Without interference from nearby live conductors, there is no need for a dedicated person to control the hoisting rope.

[0062] For special working conditions – V-type insulator strings: For towers using V-type strings, the two sub-strings are spatially staggered. During dismantling and installation operations in phase S4, different heavy-duty drone approach and hoisting paths should be used for the two insulator strings of the same V-string. For example, one sub-string can be hoisted in from the outside of the tower, while the other sub-string can be hoisted in from the inside. This differentiated path strategy effectively avoids interference or entanglement between the hoisting rope 2 and the other sub-string or fittings, ensuring smooth and safe operation. Figure 10 , 11 The middle arrow indicates the direction of descent.

[0063] The above are specific embodiments of the present invention, which demonstrate the outstanding substantive features and significant progress of the present invention. Based on the actual needs of use, equivalent modifications in shape, structure, etc., can be made to it according to the teachings of the present invention, and all such modifications are within the scope of protection of this solution.

Claims

1. A method for replacing composite insulator strings with the assistance of a heavy-duty unmanned aerial vehicle (UAV), characterized in that... Includes the following steps: 1) Ground preparation and mounting: Inspect and pre-assemble the tensioning tools and backup protective ropes on the ground, and mount the tensioning tools under the sling of the heavy-duty UAV. 2) Aerial transport and positioning: Control the heavy-duty UAV to fly to the side of the tower operation point and control it to land slowly so that the upper and lower connection points of the tensioning tool are basically flush with the construction holes at the tower end and the conductor end. 3) Wire tensioning system connection and load transfer: The upper end of the wire tensioning tool is connected to the construction hole at the end of the tower by the tower workers; Subsequently, the heavy-duty drone is slowly lowered to transfer the load on the tensioning tool from the hoisting rope to the tower; after confirming that the load transfer is stable, the tensioning tool is separated from the hoisting rope; and the lower end of the tensioning tool is connected to the conductor by the tower workers. 4) Insulator string replacement: The old insulator string is tied and fixed to the hoisting rope of the heavy-duty drone as a fall protection. Then, the tensioning tool is used to loosen the old insulator string to be replaced and remove it from the hardware. The heavy-duty drone is then slowly raised to apply force to the old insulator string. The heavy-duty drone lifts it off and transports it to the ground. Then, the heavy-duty drone is used to hoist the new insulator string to the work point. The tower workers install the new insulator string in place and remove its binding rope. Then, the tensioning tool is used to restore the conductor to a stressed state.

2. The method for replacing composite insulator strings with the assistance of a heavy-duty UAV according to claim 1, characterized in that: The suspension rope configuration is available in two types: The lower end of the first type of suspension rope is equipped with a rabbit ear knot, which is used to hang tensioning tools and old or new insulator strings for the replacement of insulator strings on ultra-high voltage line towers. The second type of suspension rope has a rabbit ear knot at the lower end and a figure-eight knot above the rabbit ear knot. The rabbit ear knot is used to hang tensioning tools and old insulator strings, while the figure-eight knot is used to hang new insulator strings, which is for the replacement of insulator strings on ultra-high voltage line towers.

3. The method for replacing composite insulator strings with the assistance of a heavy-duty UAV according to claim 2, characterized in that: When using a rope with a rabbit-ear knot to hang a tensioning tool alone, the two upper connecting shackles at the top of the chain hoist and wire sleeve of the tensioning tool are respectively hung on the two hanging rings of the rabbit-ear knot; when using a rope to hang an old insulator string or a new insulator string alone, the lower end of the rope is connected to a short rope via a safety buckle, and the lower end of the short rope is tied to the insulator string; when using a rope to hang both a tensioning tool and an old insulator string at the same time, the two upper connecting shackles at the top of the tensioning tool are connected to one hanging ring of the rabbit-ear knot at the bottom of the rope, and the other hanging ring of the rabbit-ear knot is connected to a short rope via a safety buckle, and the lower end of the short rope is tied to the old insulator string.

4. The method for replacing composite insulator strings with the assistance of a heavy-duty UAV according to claim 3, characterized in that: The upper end of the short rope is provided with a figure-eight knot, which is used to connect to the safety buckle. The lower end of the short rope is provided with a back buckle, which is used to bind the insulator string.

5. The method for replacing composite insulator strings with the assistance of a heavy-duty UAV according to claim 1, characterized in that: In step 3), the tower workers connect and lock the upper connecting shackle on the tensioning tool to the construction hole at the tower end. They then operate the heavy-duty drone to descend slowly and at a constant speed of no more than 0.2 meters per second, gradually loosening its suspension rope. This causes the connection between the upper connecting part of the tensioning tool and the construction hole on the tower to gradually be stressed and tightened until the tensioning tool and the conductor load it carries are completely borne by the tower.

6. The method for replacing composite insulator strings with the assistance of a heavy-duty UAV according to claim 1, characterized in that: In step 2), the heavy-duty UAV maintains a safe distance of more than 10 meters from the tower structure when hovering, positioning, or flying.

7. The method for replacing composite insulator strings with the assistance of a heavy-duty UAV according to claim 1, characterized in that: When the working tower is a double-circuit tower and the adjacent circuit is energized and it is necessary to carry out work near the energized circuit, during the descent process in step 2) and the hoisting process in step 4), guy ropes controlled by a dedicated person are set at each level of the tower's crossarms. The guy ropes actively guide and constrain the swing path of the hoisting rope and the suspended object, so that they pass through the preset safety passage.

8. A method for replacing composite insulator strings assisted by a heavy-duty UAV according to claim 7, characterized in that: When replacing the upper phase insulator string, the guy rope is set at the ground wire crossarm; when replacing the middle phase insulator string, the guy rope is set at both the upper phase crossarm and the ground wire crossarm; when replacing the lower phase insulator string, the guy rope is set at the upper phase crossarm, the middle phase crossarm, and the ground wire crossarm.

9. A method for replacing composite insulator strings assisted by a heavy-duty UAV according to claim 1, characterized in that: When the work involves V-type insulator strings, the removal and installation of the two sub-strings should be carried out using different heavy-duty drones with different hoisting paths.

10. A method for replacing composite insulator strings assisted by a heavy-duty UAV according to claim 1, characterized in that: The length L of the sling for the heavy-duty UAV must satisfy the following relationship for pre-configuration or verification: ;in, To ensure a safe distance between heavy-duty drones and towers, The vertical height difference between the work point conductor and the nearest obstacle point above the tower. The total added value includes the length of the tying point, the operating margin, and the environmental wind deflection compensation.

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