A method and system for active lightning protection of an offshore platform

Abstract

This invention relates to the field of lightning protection technology for offshore platforms, specifically to an active lightning protection method and system for offshore platforms. The method includes early warning monitoring, UAV deployment, active lightning attraction, and recovery and reuse. High-risk lightning strike locations are determined using lightning early warning equipment. A rotary-wing lightning-attracting UAV is controlled to fly to a safe distance from the platform. During ascent, a conductive metal wire is released to create a conductive channel. Lightning is then attracted by a lightning rod, and the charge is conducted to the sea surface. After completion, the UAV is recovered and reused. The system includes modules for early warning monitoring, UAV lightning attraction, control, and recovery and maintenance. A lightweight Faraday cage is installed on the outside of the UAV for lightning protection shielding. This invention achieves dual protection against both direct and indirect lightning effects, is adaptable to harsh marine environments, has high lightning attraction efficiency, reusable equipment, reduces protection costs, and is suitable for various fixed and mobile offshore platforms, possessing broad engineering application value.

Description

Technical Field

[0001] This invention relates to the field of lightning protection technology for offshore platforms, specifically to an active lightning protection method and system for offshore platforms. Background Technology

[0002] Offshore platforms, as core infrastructure for offshore oil and gas development and operations, are constantly exposed to the harsh marine environment, making them vulnerable to lightning strikes. A lightning strike on an offshore platform not only causes direct damage, leading to structural damage and equipment burnout, but also generates a powerful electromagnetic pulse, indirectly interfering with or damaging the platform's electronic information, navigation, communication, control, and monitoring systems. This severely impacts the normal operation of the offshore platform and can even threaten the lives of personnel.

[0003] Current lightning protection for offshore platforms primarily employs passive methods, such as installing fixed lightning rods or lightning protection strips. These methods offer limited protection, only covering the area around the lightning rod and failing to actively guide lightning away from the platform. Furthermore, they are ineffective against indirect lightning effects. While some movable and retractable lightning rods can achieve height self-adaptation, they still fall under the category of passive lightning attraction, unable to flexibly adjust their lightning attraction position and struggling to cope with the complex and ever-changing marine thunderstorm environment. In addition, existing drone-based lightning attraction technologies are mostly applied to land-based scenarios and have not been adapted to the unique marine environment of high salt spray, strong winds, and high humidity. Drones are susceptible to lightning strike damage, and their lightning attraction efficiency and reusability are insufficient, failing to meet the long-term, stable lightning protection requirements of offshore platforms. Therefore, developing a proactive lightning protection method and system for offshore platforms that can actively guide lightning, adapt to the marine environment, provide comprehensive protection, and is economically feasible has become an urgent technical challenge. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for active lightning protection of offshore platforms, which guides lightning to a safe area outside the platform through active lightning attraction, thereby achieving dual protection against direct lightning strikes and indirect effects, while improving lightning attraction efficiency, equipment durability and reusability, reducing protection costs, and adapting to the complex and harsh marine environment.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An active lightning protection method for offshore platforms includes the following steps: S1, Early Warning Monitoring: Lightning warning equipment is deployed at multiple preset locations on the offshore platform to monitor the atmospheric electric field intensity, thunderstorm cloud development trend and lightning direction around the platform in real time. Atmospheric electric field intensity threshold and electric field gradient change rate threshold are set to determine the high-risk direction of lightning strikes and generate corresponding early warning information. S2, UAV deployment: Based on the warning information, the control module controls the lightning-attracting UAV to take off from the deployment site on the offshore platform, fly towards the high-risk direction of lightning strikes, and after reaching a distance of more than a preset safe distance from the offshore platform, stay there and maintain a stable attitude. S3, Active lightning attraction, controls the lightning-attracting drone to rise vertically to the preset lightning contact height, and during the ascent, releases the wound conductive metal wire synchronously through the electric winding shaft. By adjusting the speed of the winding shaft, the center of gravity ball at the end of the conductive metal wire is kept at a preset gap or in contact with the sea surface to construct a conductive channel between the thundercloud and the sea surface. S4. Recycling and Reuse: If the lightning-attracting drone has been struck by lightning before retrieval, the conductive metal wire and the center of gravity ball will melt and disperse under the action of lightning current and fall into the sea. In this case, the control module will control the lightning-attracting drone to stop releasing the metal wire, and at the same time, retrieve the remaining parts of the lightning-attracting drone to the offshore platform and replace them with new conductive metal wire spools and center of gravity balls for use in the next active lightning attraction. If the lightning-attracting drone has not been struck by lightning before retrieval, the drone will be controlled to descend vertically, and the conductive metal wire will be retrieved synchronously through an electric reel during the descent. After all the conductive metal wire has been retrieved, the drone will be retrieved to the platform, inspected, and put into use.

[0006] Preferably, in step S1, the lightning warning device includes an atmospheric electric field monitoring device, a weather radar, and a lightning location system; the atmospheric electric field strength threshold is 8~12kV / m, and the electric field gradient change rate threshold is ≥500V / m / s; When the atmospheric electric field intensity at a certain location exceeds the atmospheric electric field intensity threshold, or the electric field gradient change rate exceeds the electric field gradient change rate threshold, that location is determined to be a high-risk location for lightning strikes.

[0007] Preferably, in step S2, the lightning-attracting drone is a rotary-wing type, and the preset safe distance is 200m~1000m. During flight, the lightning-attracting drone feeds back its position information to the control module in real time through its own navigation and positioning module. The control module dynamically fine-tunes the dwell position and altitude of the lightning-attracting drone according to the development trend of the thunderstorm cloud, in preparation for active lightning attraction.

[0008] Preferably, in step S3, the preset lightning interception height is 500m to 2000m above the sea surface, and the release speed of the conductive metal wire is adapted to the ascent speed of the lightning-attracting drone. As the lightning-inducing drone ascends, the top lightning rod receives a downward leader from the thundercloud, triggering a lightning discharge. The charge and energy in the thundercloud are then guided to the sea surface through the conductive metal wire and the center of gravity sphere, thus completing the active lightning induction. If the lightning-attracting drone rises to the preset lightning-attracting height and remains there for more than the preset time T without receiving a lightning strike, or if the control module determines that the lightning strike risk has decreased based on the feedback signal from the early warning device, the lightning-attracting drone recovery process will be initiated.

[0009] Preferably, the lightning-attracting drone includes a rotary-wing drone body 4, with a Faraday cage 2 surrounding the outer ring of the drone body 4. A lightning-attracting pin 1 is installed on the top of the Faraday cage 2, and a metal frame base 9 is connected to the bottom of the Faraday cage 2. An electric winding shaft 8 is installed inside the metal frame base 9, and a conductive metal wire 10 is wound on the electric winding shaft 8. A center-of-gravity ball 11 is installed at the end of the conductive metal wire 10 that extends out of the metal frame base 9, and a bottom metal wire 12 is connected to the bottom of the center-of-gravity ball 11.

[0010] Preferably, the Faraday cage 2 is connected and installed on the outer ring of the UAV body 4 via an insulating bracket 3, and the Faraday cage 2 is specifically a flattened spherical Faraday cage constructed of lightweight metal material.

[0011] Preferably, the mesh size of the Faraday cage 2 is calculated and determined based on the operating frequency of the lightning-attracting drone and the frequency of the lightning electromagnetic pulse, so as to shield the lightning electromagnetic pulse without affecting the working signal transmission of the lightning-attracting drone.

[0012] An active lightning protection system for an offshore platform, employing the active lightning protection method described above, includes: an early warning and monitoring module, a UAV lightning attraction module, a control module, and a recovery and maintenance module; The early warning and monitoring module includes a lightning early warning device, used to monitor the risk of lightning strikes and issue early warnings; The UAV mine-guiding module includes a mine-guiding UAV, which receives instructions from the control module to perform active mine-guiding tasks. The control module is used to receive early warning information from the early warning monitoring module and send corresponding control commands to the UAV mine-attracting module and the recovery and maintenance module. The recycling and maintenance module includes a drone deployment and recycling station, a spool replacement device, and maintenance tools.

[0013] Preferably, the lightning-attracting drone is equipped with a status monitoring component, which includes a data transmission module, an image transmission module, and a camera, for real-time feedback of the drone's flight status, the winding status of the metal wire spool, and the lightning strike status to the control module.

[0014] Preferably, the control module is located in the control center of the offshore platform and includes a main control unit, a communication unit, and a display unit; The drone deployment and recovery station is used for parking, charging, and securing the drone; the spool replacement device is used to replace the conductive metal wire spool damaged after the lightning-attracting drone is struck by lightning; and the inspection tools are used to inspect and maintain the components of the recovered lightning-attracting drone.

[0015] Compared with the prior art, the present invention has the following main advantages: 1. This invention actively guides lightning to a safe area outside the platform, effectively avoiding structural damage and equipment burnout caused by direct lightning strikes on the offshore platform, thus achieving reliable protection against the direct effects of lightning. At the same time, because the lightning channel is far from the platform, the amplitude and rate of change of the lightning electromagnetic pulse are greatly attenuated when it propagates to the platform, significantly reducing interference and damage to the platform's electronic information, navigation and communication systems, thus achieving effective protection against the indirect effects of lightning. This solves the technical problem that traditional passive protection cannot achieve dual protection, and greatly improves the comprehensiveness and reliability of lightning protection for offshore platforms.

[0016] 2. This invention uses a lightweight Faraday cage to protect the drone, which can effectively shield against lightning electromagnetic pulses, protect the drone's electronic system from damage, and ensure that drone control and data transmission signals can pass through normally. It is also suitable for strong winds and high salt spray environments at sea. The optimized design of the lightning arrestor and center of gravity ball greatly improves the lightning arrest efficiency. The coordinated control of the wire retraction and extension with the drone's ascent and descent reduces lift resistance and torque, saves drone power, extends loiter time, and further improves the efficiency and stability of active protection.

[0017] 3. This invention has good economic efficiency and scalability. Core components such as drones and electric reel spools can be recycled and reused. Only the conductive metal wire reel spool needs to be replaced to put it back into use, which greatly reduces the long-term cost of active protection. The system can flexibly deploy single, multiple or multiple drones according to the intensity and threat level of thunderstorm clouds, adapting to the protection needs of different types of fixed and mobile offshore platforms. Attached Figure Description

[0018] Figure 1 This is an overall flowchart of the active lightning protection method for offshore platforms in an embodiment of the present invention; Figure 2 This is a schematic diagram of the active lightning protection method for offshore platforms in an embodiment of the present invention. Figure 3 This is a schematic diagram of the composition of the lightning-guided rotary-wing UAV in an embodiment of the present invention.

[0019] In the diagram: 1-Lightning pin, 2-Faraday cage, 3-Insulating bracket, 4-UAV body (containing battery, control, data transmission, image transmission, and satellite positioning modules), 5-UAV antenna, 6-UAV rotor, 7-Camera, 8-Electric winding spool, 9-Metal frame base, 10-Conductive metal wire, 11-Center of gravity sphere, 12-Bottom metal wire of the sphere. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0022] In this invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0023] Example 1: This example provides an active lightning protection method for offshore platforms, such as... Figure 1 As shown, the main steps include the following: Step S1, Early Warning Monitoring: At multiple preset locations on the offshore platform (bow, stern, port side, starboard side), a set of lightning early warning equipment consisting of atmospheric electric field monitoring equipment, meteorological radar, and lightning location system is deployed to monitor the atmospheric electric field intensity, thunderstorm cloud development trend, and lightning direction around the platform in real time, and set atmospheric electric field intensity threshold (8~12kV / m) and electric field gradient change rate threshold (≥500V / m / s). When the atmospheric electric field intensity in a certain direction is detected to rise rapidly and reach a preset threshold, or when the weather radar predicts that lightning may occur in that direction in the next few minutes, the risk of lightning strike in that direction is determined to be high, the active lightning triggering preparation process is initiated, and the early warning information is transmitted to the platform control module, which then formulates a lightning triggering strategy.

[0024] Step S2, UAV Deployment: Based on the early warning information, the control module controls the lightning-attracting UAV to take off from the deployment site on the offshore platform. The UAV adopts a rotor structure adapted to the offshore environment. After takeoff, it first flies at a low altitude in a horizontal flight mode to quickly reach a safe distance (200m~1000m) from the platform in the high-risk direction of lightning strikes, where it hovers and adjusts its attitude to ensure flight stability. During the flight, the UAV provides real-time feedback of its position information through its own navigation and positioning module. The control module fine-tunes the UAV's hovering position and altitude based on the dynamic development of the thunderstorm cloud to prepare for active lightning attraction.

[0025] Step S3, Active Lightning Trigger: After the UAV stabilizes at the designated location, it begins to ascend vertically. During ascent, the electric reel on the UAV body is simultaneously controlled to rapidly release the wound conductive metal wire at a rate matching the ascent speed. By adjusting the speed of the reel, the center of gravity ball at the end of the conductive metal wire is kept at a small gap or in contact with the sea surface, establishing a low-impedance conductive channel between the thundercloud and the sea surface. The UAV continues to ascend to a preset altitude (500m~2000m). If the lightning arresting needle at the top receives a downward leader from the thundercloud during the ascent, a lightning discharge is triggered, and the charge and energy in the thundercloud are guided to the sea surface through the conductive metal wire and the center of gravity ball, completing the active lightning trigger. If no lightning strike occurs after ascending to the highest preset altitude, the UAV remains at that altitude for a period of time, continuously maintaining the conductive channel until the thundercloud develops to a sufficiently strong electric field to the ground to complete the lightning strike, or the control module initiates the recovery process based on the risk descent signal fed back by the early warning equipment.

[0026] Step S4, Recycling and Reuse: After a successful lightning strike, the conductive metal wire and the center-of-gravity ball melt and disperse under the influence of the lightning current, falling into the sea. The control module controls the UAV to stop releasing the metal wire and initiates the recovery procedure, recovering the UAV along with the Faraday cage, metal frame base, electric reel, and other components to the offshore platform. After replacing the reel with a new one containing the conductive metal wire, it can be used for the next active lightning strike. If no lightning strike occurs and the risk of a lightning strike decreases, the UAV descends vertically, simultaneously controlling the electric reel in the opposite direction to reduce the recovery torque. After recovering all the conductive metal wire, the UAV is then recovered to the platform for inspection and backup. During the recovery process, the UAV's data transmission and image transmission modules provide real-time feedback on the equipment status and the entanglement of the metal wire, ensuring safe recovery.

[0027] In this embodiment, to adapt to the harsh marine environment, the lightning-attracting drone is reinforced for lightning protection and environmental adaptation: a flat spherical Faraday cage is constructed using lightweight metal materials to enclose the main body of the drone. The mesh size of the Faraday cage is optimized according to the drone's operating frequency (above 800MHz) and the frequency of lightning electromagnetic pulses (hundreds of kHz to tens of MHz) to ensure that the drone's remote control, image transmission, data transmission, satellite positioning and other working signals can penetrate, while effectively shielding against lightning electromagnetic pulses; a lightweight metal lightning rod is installed on the top of the Faraday cage, and a metal frame base is installed at the bottom. The metal frame base is electrically connected to the Faraday cage, and an electric winding spool is installed on the base.

[0028] In this embodiment, the rotary-wing UAV is fixed inside the Faraday cage by the insulating brackets 3 arranged vertically. The Faraday cage is provided with a movable opening to facilitate the installation and maintenance of the UAV. After the movable opening is closed and fixed, the whole structure forms a good conductive cage. In this embodiment, a lightweight metal lightning rod 1 is installed on the top of the Faraday cage by welding or screwing to change the local electric field distribution and make it easier to receive lightning leaders. In this embodiment, a lightweight metal frame base 9 is installed at the bottom of the Faraday cage 3 for installing the electric reel 8 and for stabilizing the UAV during deployment and recovery on the offshore platform. The metal frame base and the Faraday cage are electrically connected through multi-point screwing or welding. In this embodiment, the lightning-attracting rotary-wing UAV is launched from the sea platform. After flying to the designated position at a low altitude, it begins to ascend vertically. During the ascent, the conductive metal wire 10 wound on the spool is quickly released by synchronously controlling the electric winding spool 8 to reduce the upward resistance. By adjusting the rotation speed, the center of gravity ball 11 is kept at a small gap from the sea surface. In this embodiment, after the lightning strike is successful, the conductive metal wire 10 will melt and disperse under the action of the lightning current of the center of gravity sphere 11 and fall into the sea. The rotary-wing UAV 4, together with the Faraday cage 2, the lightweight metal frame base 9, the electric reel 8, etc., will be recovered to the offshore platform. The reel with the conductive metal wire can be replaced and reused. In this embodiment, if the drone remains stationary for a period of time without encountering lightning, and the local lightning risk indicated by the atmospheric electric field monitoring equipment on the platform decreases, the drone can be controlled to descend. Simultaneously, the electric reel 8 is controlled in reverse to reduce the recovery torque when retrieving the conductive metal wire 10. Once all the conductive metal wire 10 has been retrieved, the drone can be recovered to the offshore platform for future use in active lightning strikes.

[0029] Example 2: This example provides an active lightning protection method for offshore platforms, such as... Figure 2As shown, based on the judgment of lightning location and threat level by atmospheric electric field monitoring equipment and meteorological radar on the offshore platform, if a lightning strike is expected in a certain location near the platform within the next few minutes, a lightning-attracting rotary-wing drone is launched from the platform to fly horizontally at low altitude to a location 200m-1000m away. After hovering, it begins to ascend, simultaneously releasing a center-of-gravity sphere and a conductive metal wire at the same speed, allowing the center-of-gravity sphere to approach or contact the sea surface. The lightning-attracting drone can ascend to an altitude of 500m-2000m. During the ascent, the lightning-attracting needle on the top of the drone may catch the downward leader in the thundercloud, causing a lightning discharge. It may also fail to catch the lightning even when it reaches its highest position. In this case, the drone can hover for a period of time to build a low-impedance conductive channel between the thundercloud and the sea surface. When the thundercloud further develops to a sufficiently strong electric field to the ground, the lightning will be triggered, thus providing lightning protection for the offshore platform. Depending on the intensity of the thunderstorm cloud and the degree of threat it poses to the offshore platform, one, multiple, or continuous lightning-attracting drones can be deployed to different locations on the offshore platform to effectively protect it. The drones, un-melted conductive wires, and center-of-gravity balls can all be recycled and reused to reduce the cost of active protection.

[0030] In this embodiment, the composition of the lightning-attracting rotary-wing UAV is as follows: Figure 3 As shown, the lightning rod 1 at the top of the Faraday cage can be made of an aluminum alloy tube with an outer diameter of 20mm, a wall thickness of 2mm, and a length of about 1m. The top is sealed with a hemispherical shape of the same material and a diameter of 20mm to reduce the influence of corona shielding and achieve a better lightning reception effect. In this embodiment, the Faraday cage 2 specifically uses lightweight aluminum alloy profiles as the skeleton, with lighter copper mesh used in some areas to reduce the overall weight. The dimensions can be determined based on the unfolded dimensions of the rotorcraft drone, ensuring the safety of the drone's rotor and providing sufficient protective space. The drone's remote control module and image transmission module use the 2.4GHz or 5.8GHz frequency band, while the satellite positioning module uses the 1.5GHz frequency band. The satellite positioning module operates at the lowest frequency, with a wavelength of 20cm. Taking the highest frequency component of lightning, 100MHz, with a wavelength of 300cm, when the side length of the Faraday cage mesh is 10cm, the working signal can penetrate while shielding against lightning pulses. The optimized design of the Faraday cage has an acceptable aerodynamic impact on the drone.

[0031] In this embodiment, the UAV 4 is specifically a small-to-medium-sized quadcopter 8-propeller UAV with a maximum flight altitude of over 2000m, a maximum horizontal flight speed of over 20m / s, a maximum ascent speed of 8m / s, a maximum descent speed of 4m / s, a maximum payload of over 20kg, a wind resistance of over level 6, and the ability to operate normally in an ambient temperature range of -20 to +40℃.

[0032] In this embodiment, the fixed insulating bracket 3 is made of lightweight fiberglass profile. The total weight of the protective Faraday cage 2, the lightning rod 1, the fixed insulating bracket 3, the metal frame base 12, etc., shall not exceed 20% of the maximum load of the rotary-wing UAV while ensuring structural strength.

[0033] In this embodiment, the conductive metal wire 10 is specifically made of steel wire or stainless steel wire (containing chromium and nickel) with a diameter of 0.2mm, which has good tensile strength and conductivity. The surface is treated with anti-rust and corrosion-resistant treatment to prevent the strength of the conductive metal wire from decreasing after rusting.

[0034] In this embodiment, the center of gravity sphere 11 is specifically a solid stainless steel sphere with a diameter of about 30mm, which is connected to the conductive metal wire 10 and the bottom metal wire 12 by screwing. The bottom metal wire 12 can be a copper rod or a stainless steel rod with a diameter of about 3mm and a length of about 100mm.

[0035] Example 3, based on the same inventive concept, also provides an active lightning protection system for offshore platforms, which adopts the active lightning protection method described above, mainly including: 1) Early Warning and Monitoring Module: This module consists of atmospheric electric field monitoring equipment deployed at different locations on the offshore platform, a weather radar, a lightning location system, and a data transmission unit. The atmospheric electric field monitoring equipment uses high-sensitivity sensors with a range of ±20kV / m and a response time of less than 1ms, enabling real-time acquisition of atmospheric electric field intensity and rate of change data. The weather radar is used to monitor the location, development speed, and intensity of thunderstorm clouds. The lightning location system uses the electromagnetic wave triangulation method, achieving a positioning accuracy of 0.5~1km. The data transmission unit transmits the monitoring data to the control module in real-time via 4G / 5G or satellite communication to complete lightning strike risk assessment and early warning.

[0036] 2) UAV Lightning Attraction Module: This includes a lightning-attracting UAV, a Faraday cage protection assembly, a lightning arrestor assembly, a wire release assembly, and a status monitoring assembly. The lightning-attracting UAV adopts a small-to-medium-sized 4-axis 8-propeller rotor structure, with a maximum flight altitude ≥2000m, a maximum horizontal flight speed ≥20m / s, wind resistance ≥6, and can operate normally within an ambient temperature range of -20~+40℃. Its maximum load is ≥20kg. The Faraday cage protection assembly uses lightweight aluminum alloy profiles as the frame, with copper mesh laid in certain areas. The mesh side length is ≤10cm, and the overall structure is a flattened spherical cage with movable openings. The lightning arrestor assembly includes installation... The lightweight metal lightning rod at the top of the Faraday cage is made of aluminum alloy tubing with a hemispherical closed structure at the top. The metal wire release assembly includes an electric winding spool, a conductive metal wire, and a center of gravity ball mounted on a metal frame base. The conductive metal wire is made of rust-resistant and corrosion-resistant steel or stainless steel wire with a diameter of 0.1~0.3mm, and the surface can be covered with a nylon layer to enhance its strength. The center of gravity ball is a solid stainless steel ball with a short metal rod connected to the bottom. The status monitoring assembly includes a data transmission module, an image transmission module, and a camera mounted on the drone, used to provide real-time feedback on the drone's flight status, the winding status of the metal wire spool, and the lightning interception status.

[0037] 3) Control Module: Located in the control center of the offshore platform, it includes a main control unit, a communication unit, and a display unit. The main control unit uses an embedded processor to receive monitoring data from the early warning and monitoring module, determine the risk of lightning strikes, and generate control commands for UAV deployment, lightning strike attraction, and recovery. The communication unit enables two-way communication with the UAV, the early warning and monitoring module, and the recovery and maintenance module to ensure the stability of command transmission and data feedback. The display unit displays early warning information, UAV status, lightning strike process, and other data in real time, facilitating real-time monitoring and manual intervention by staff.

[0038] 4) Recycling and Maintenance Module: This module includes drone deployment and recycling stations, spool replacement devices, and maintenance tools. The deployment and recycling stations are used for parking, charging, and securing drones. The spool replacement devices are used to quickly replace conductive metal spools damaged after a lightning strike. The maintenance tools are used to inspect and maintain the recycled drones, Faraday cages, electric winding spools, and other components to ensure long-term stable operation of the equipment.

[0039] In this embodiment, depending on the intensity of the thunderstorm cloud and the degree of threat to the offshore platform, the control module can control the release of one, multiple, or continuous release of multiple lightning-attracting drones to different locations on the platform to achieve all-round active protection; all recyclable components are made of rust-proof and corrosion-resistant materials and have anti-salt spray treatment on the surface to adapt to the high salt spray and high humidity environment at sea.

[0040] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0041] In summary: 1. This invention actively guides lightning to a safe area outside the platform, effectively avoiding structural damage and equipment burnout caused by direct lightning strikes on the offshore platform, thus achieving reliable protection against the direct effects of lightning. At the same time, because the lightning channel is far from the platform, the amplitude and rate of change of the lightning electromagnetic pulse are greatly attenuated when it propagates to the platform, significantly reducing interference and damage to the platform's electronic information, navigation and communication systems, thus achieving effective protection against the indirect effects of lightning. This solves the technical problem that traditional passive protection cannot achieve dual protection, and greatly improves the comprehensiveness and reliability of lightning protection for offshore platforms.

[0042] 2. This invention uses a lightweight Faraday cage to protect the drone, which can effectively shield against lightning electromagnetic pulses, protect the drone's electronic system from damage, and ensure that drone control and data transmission signals can pass through normally. It is also suitable for strong winds and high salt spray environments at sea. The optimized design of the lightning arrestor and center of gravity ball greatly improves the lightning arrest efficiency. The coordinated control of the wire retraction and extension with the drone's ascent and descent reduces lift resistance and torque, saves drone power, extends loiter time, and further improves the efficiency and stability of active protection.

[0043] 3. This invention has good economic efficiency and scalability. Core components such as drones and electric reel spools can be recycled and reused. Only the conductive metal wire reel spool needs to be replaced to put it back into use, which greatly reduces the long-term cost of active protection. The system can flexibly deploy single, multiple or multiple drones according to the intensity and threat level of thunderstorm clouds, adapting to the protection needs of different types of fixed and mobile offshore platforms.

[0044] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0045] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0046] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for active lightning protection of offshore platforms, characterized in that, Includes the following steps: S1, Early Warning Monitoring: Lightning warning equipment is deployed at multiple preset locations on the offshore platform to monitor the atmospheric electric field intensity, thunderstorm cloud development trend and lightning direction around the platform in real time. Atmospheric electric field intensity threshold and electric field gradient change rate threshold are set to determine the high-risk direction of lightning strikes and generate corresponding early warning information. S2, UAV deployment: Based on the warning information, the control module controls the lightning-attracting UAV to take off from the deployment site on the offshore platform, fly towards the high-risk direction of lightning strikes, and after reaching a distance of more than a preset safe distance from the offshore platform, stay there and maintain a stable attitude. S3, Active lightning attraction, controls the lightning-attracting drone to rise vertically to the preset lightning contact height, and during the ascent, releases the wound conductive metal wire synchronously through the electric winding shaft. By adjusting the speed of the winding shaft, the center of gravity ball at the end of the conductive metal wire is kept at a preset gap or in contact with the sea surface to construct a conductive channel between the thundercloud and the sea surface. S4, Recycling and Reuse: If the lightning-attracting drone has been struck by lightning before its recovery, the conductive metal wire and the center ball will melt and disperse under the action of the lightning current and fall into the sea. The control module will then control the lightning-attracting drone to stop releasing the metal wire and recover the remaining parts of the lightning-attracting drone to the offshore platform. New conductive metal wire spools and center balls will be replaced for use in the next active lightning attraction. If the lightning-attracting drone is not connected to a lightning strike point before retrieval, the drone will be controlled to descend vertically, and the conductive metal wire will be retrieved synchronously via an electric reel during the descent. After all the conductive metal wire has been retrieved, the drone will be retrieved to the platform for inspection and backup.

2. The active lightning protection method for offshore platforms according to claim 1, characterized in that... In step S1, the lightning warning equipment includes atmospheric electric field monitoring equipment, meteorological radar, and lightning location system; the atmospheric electric field strength threshold is 8~12kV / m, and the electric field gradient change rate threshold is ≥500V / m / s; When the atmospheric electric field intensity at a certain location exceeds the atmospheric electric field intensity threshold, or the electric field gradient change rate exceeds the electric field gradient change rate threshold, that location is determined to be a high-risk location for lightning strikes.

3. The active lightning protection method for offshore platforms according to claim 1, characterized in that... In step S2, the lightning-attracting drone is a rotary-wing type, and the preset safe distance is 200m~1000m. During flight, the lightning-attracting drone feeds back its position information to the control module in real time through its own navigation and positioning module. The control module dynamically fine-tunes the dwell position and altitude of the lightning-attracting drone according to the development trend of the thunderstorm cloud, in preparation for active lightning attraction.

4. The active lightning protection method for offshore platforms according to claim 1, characterized in that... In step S3, the preset lightning interception height is 500m to 2000m above the sea surface, and the release speed of the conductive metal wire is adapted to the ascent speed of the lightning-attracting drone. As the lightning-inducing drone ascends, the top lightning rod receives a downward leader from the thundercloud, triggering a lightning discharge. The charge and energy in the thundercloud are then guided to the sea surface through the conductive metal wire and the center of gravity sphere, thus completing the active lightning induction. If the lightning-attracting drone rises to the preset lightning-attracting height and remains there for more than the preset time T without receiving a lightning strike, or if the control module determines that the lightning strike risk has decreased based on the feedback signal from the early warning device, the lightning-attracting drone recovery process will be initiated.

5. The active lightning protection method for offshore platforms according to claim 3, characterized in that, The lightning-attracting drone includes a rotor-type drone body (4), with a Faraday cage (2) covering the outer ring of the drone body (4). A lightning-attracting needle (1) is installed on the top of the Faraday cage (2), and a metal frame base (9) is connected to the bottom of the Faraday cage (2). An electric winding shaft (8) is installed inside the metal frame base (9), and a conductive metal wire (10) is wound on the electric winding shaft (8). A center of gravity ball (11) is installed at the end of the conductive metal wire (10) that passes through the metal frame base (9), and a bottom metal wire (12) is connected to the bottom of the center of gravity ball (11).

6. The active lightning protection method for offshore platforms according to claim 5, characterized in that, The Faraday cage (2) is connected and installed on the outer ring of the UAV body (4) via an insulating bracket (3), and the Faraday cage (2) is specifically a flat spherical Faraday cage constructed of lightweight metal material.

7. The active lightning protection method for offshore platforms according to claim 6, characterized in that, The mesh size of the Faraday cage (2) is calculated and determined based on the operating frequency of the lightning-attracting drone and the frequency of the lightning electromagnetic pulse, so as to shield the lightning electromagnetic pulse and not affect the working signal transmission of the lightning-attracting drone.

8. A lightning active protection system for an offshore platform, employing the lightning active protection method as described in any one of claims 1 to 8, characterized in that, include: Early warning and monitoring module, UAV mine-attracting module, control module, and recovery and maintenance module; The early warning and monitoring module includes a lightning early warning device, used to monitor the risk of lightning strikes and issue early warnings; The UAV mine-guiding module includes a mine-guiding UAV, which receives instructions from the control module to perform active mine-guiding tasks. The control module is used to receive early warning information from the early warning monitoring module and send corresponding control commands to the UAV mine-attracting module and the recovery and maintenance module. The recycling and maintenance module includes a drone deployment and recycling station, a spool replacement device, and maintenance tools.

9. The active lightning protection system for an offshore platform according to claim 8, characterized in that, The lightning-attracting drone is equipped with a status monitoring component, which includes a data transmission module, an image transmission module, and a camera. This component is used to provide real-time feedback on the drone's flight status, the winding status of the metal wire spool, and the lightning strike status to the control module.

10. The active lightning protection system for an offshore platform according to claim 8, characterized in that, The control module is located in the control center of the offshore platform and includes a main control unit, a communication unit, and a display unit. The drone deployment and recovery station is used for parking, charging, and securing the drone; the spool replacement device is used to replace the conductive metal wire spool damaged after the lightning-attracting drone is struck by lightning; and the inspection tools are used to inspect and maintain the components of the recovered lightning-attracting drone.

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