A mooring force regulation and energy recovery system and method for a floating offshore photovoltaic platform

Abstract

The application discloses a kind of offshore floating photovoltaic platform mooring force regulation and energy recovery system and method.The system includes offshore floating photovoltaic platform, direction self-adaptive guiding device, mooring force regulation and energy recovery device, mooring assembly, counterweight compensation assembly and monitoring and control system.Direction self-adaptive guiding device is set on platform steel frame, so that chain wheel entry chain direction can be adjusted with mooring stress direction change.Platform relative to anchoring base movement, chain drive sprocket, transmission shaft and generator reciprocating rotation, and drive counterweight block lifting.Controller with one or more chain release-recovery cycle constitutes evaluation period, extracts the displacement characteristic quantity of chain, counterweight block or platform, and accordingly updates target electromagnetic damping.Generator applies opposite direction electromagnetic damping and recovers mechanical energy in the process of chain bidirectional reciprocating motion.The application can consider mooring load reduction, displacement safety, direction adaptation and energy recovery.

Description

Technical Field

[0001] This invention belongs to the field of marine engineering equipment and marine renewable energy technology, specifically relating to a system and method for mooring force regulation and energy recovery of a floating photovoltaic platform based on adjustable electromagnetic damping. Background Technology

[0002] Offshore floating photovoltaic (PV) platforms typically consist of multiple floating units, PV modules, PV module supports, and connecting components. A multi-point mooring system restricts the platform's overall drift under the influence of wind, waves, currents, and tides. Compared to ships, floating wind power platforms, and traditional oil and gas platforms, offshore floating PV platforms generally have characteristics such as large coverage area, shallow draft, numerous modules, complex array connections, and greater sensitivity to horizontal displacement. Their mooring systems not only serve the platform's positioning function but also directly affect the stress safety of floating unit connections, PV module supports, submarine cables, and anchoring foundations.

[0003] Existing offshore floating photovoltaic platforms typically employ catenary mooring, tensioned mooring, or a combination of mooring systems composed of different types of cables. Catenary mooring relies primarily on the weight of the mooring cable itself, changes in the suspension profile, and variations in the length of the section lying on the seabed to provide restoring force, exhibiting good geometric compliance when platform displacement is small. However, as platform displacement increases, the section lying on the seabed gradually shortens, and the suspension section gradually straightens, leading to an increase in the equivalent stiffness of the mooring system and a tendency for mooring forces to grow rapidly. Tensioned mooring, on the other hand, applies higher pretension, allowing the mooring cable to primarily rely on axial elongation and changes in spatial configuration to provide restoring force. It features a smaller deployment range and higher positioning accuracy, but its initial stiffness is usually higher. When the platform experiences significant displacement or is subjected to sudden environmental loads, the tension in the mooring cable may also increase rapidly, transferring large vertical or inclined loads to the anchoring foundation.

[0004] In shallow waters, the available hanging space and range of variation in the lying section of catenary mooring are limited, making it prone to prematurely entering a high-stiffness stress phase. Tensioned mooring, on the other hand, is constrained by the pretension level, cable elongation capacity, and allowable platform offset. Excessive pretension or insufficient elongation space can increase the peak mooring force and the stress on the anchoring foundation. Therefore, under conditions of large waves, strong winds, rapid currents, or sudden loads, regardless of whether catenary or tensioned mooring is used, horizontal platform movement can cause a sudden increase in the peak mooring force and the amplitude of cyclic tension. This not only increases the ultimate bearing requirements of the mooring cable, connecting shackles, and anchoring foundation but also exacerbates fatigue damage to mooring components.

[0005] To reduce mooring loads, existing technologies typically improve the compliance of mooring systems by increasing mooring cable length, optimizing mooring radius and arrangement angle, and incorporating elastic components, buoyancy components, counterweights, or load-reducing devices. While these methods can mitigate mooring force growth to some extent, most are passive designs with fixed parameters. Their structural parameters are difficult to adjust in real-time based on platform displacement, mooring force, remaining adjustment stroke, and sea state changes after installation, leading to two potential contradictions: firstly, excessive constraints can restrict the release of displacement in the mooring cable or compensation mechanism, directly converting platform motion into a large mooring force; secondly, insufficient constraints may cause platform misalignment, compensation component stroke, or localized movement exceeding permissible limits.

[0006] Furthermore, floating photovoltaic platforms at sea continuously undergo reciprocating motion under the influence of wind, waves, and currents, resulting in periodic displacement of the mooring position relative to the anchoring foundation. Even if conventional mooring systems are used for some mooring positions, the platform can still experience swaying, rolling, bowing, and other movements within the design limits. These reciprocating displacements cause periodic changes in the tension of the mooring cables and also contain a certain amount of recoverable mechanical energy. However, existing mooring systems typically rely mainly on cable friction, fluid resistance, component friction, or structural deformation to dissipate this energy, and have not yet fully utilized it in conjunction with mooring load control, platform displacement constraints, and equipment power supply requirements.

[0007] While some existing wave energy generation devices can utilize the relative motion between the floating body and the fixed foundation to drive the power generation mechanism, their design objectives are mostly focused on energy harvesting itself, and they typically do not consider the unloading requirements of the mooring system, displacement safety boundaries, and stress variations under different sea conditions. When the resistance applied by the energy recovery mechanism to the motion is too great, it may restrict the necessary displacement release in the mooring direction, thereby increasing the instantaneous tension of the mooring cable; when the resistance is too small, it is difficult to effectively limit platform offset or compensate for component travel, which can easily lead to excessive motion amplitude. Therefore, it is difficult to simultaneously meet the requirements of mooring unloading, displacement constraint, and stable power generation by simply using a fixed load or fixed damping method for energy recovery.

[0008] Meanwhile, under multi-point mooring conditions, the motion direction of the offshore floating photovoltaic platform and the horizontal force direction of each mooring cable will constantly change with the combined loads of wind, waves, and currents. If the relevant control or energy recovery devices are installed in a fixed direction at the edge of the platform, their force inlet direction may not be consistent with the actual traction direction of the mooring cable, resulting in lateral load, additional bending moment, and localized wear at the transmission components, support components, and installation structure, affecting the operational stability and long-term reliability of the device. Therefore, the relevant devices not only need to have load control and energy recovery capabilities, but also need to be able to adapt to changes in the mooring force direction and ensure the coordination of the force transmission path and the direction of the cable entry.

[0009] Therefore, there is an urgent need for a mooring force regulation and energy recovery system suitable for offshore floating photovoltaic platforms. This system should provide controlled displacement release during platform reciprocating motion, reducing peak mooring force and cyclic tension amplitude. Simultaneously, it should adjust the damping level according to the platform's motion, mooring forces, and remaining adjustment stroke to prevent displacement or compensation stroke from exceeding limits. Furthermore, it should recover some mechanical energy during the above process. In addition, the system should be able to adapt to changes in the horizontal force direction of the mooring cable, reducing lateral loads caused by fixed-direction installation, thereby balancing mooring load reduction, displacement safety, energy utilization, and engineering reliability. Summary of the Invention

[0010] To address the problems of fixed parameters, large peak mooring force, difficulty in balancing compliant unloading and displacement limitation in existing offshore floating photovoltaic platform mooring systems, and insufficient utilization of mechanical energy in the platform's reciprocating motion, this invention provides a system and method for regulating mooring force and recovering energy for offshore floating photovoltaic platforms based on adjustable electromagnetic damping.

[0011] This invention utilizes a chain-sprocket-drive shaft-generator transmission system installed at a selected mooring location on a floating photovoltaic platform to transmit the reciprocating motion of one side of the mooring cable to a counterweight compensation assembly and a generator assembly. On one hand, the counterweight provides basic tension and displacement compensation space to the chain through its lifting and lowering motion, giving the mooring additional motion compliance. On the other hand, the generator assembly adjusts the electromagnetic torque through load regulation, applying adjustable damping to the movement of the sprocket and chain, controlling the displacement of the chain, counterweight, and platform while recovering reciprocating motion energy. Simultaneously, a direction-adaptive guiding device, through the linkage between the guide connector and the mounting plate, adjusts the chain entry path of the mooring force regulation and energy recovery device according to changes in the horizontal force direction of the mooring cable, reducing lateral loads caused by fixed-direction installation.

[0012] The technical solution adopted in this invention is:

[0013] A floating photovoltaic platform mooring force regulation and energy recovery system includes a floating photovoltaic platform, a direction adaptive guidance device, a mooring force regulation and energy recovery device, a mooring component, a counterweight compensation component, and a monitoring and control system.

[0014] The floating photovoltaic platform of this invention includes floating body units, photovoltaic modules, photovoltaic module supports, floating body connectors, and a platform steel frame. Multiple floating body units are connected by floating body connectors to form a floating photovoltaic array, and the photovoltaic modules are mounted on the floating body units or the platform steel frame via photovoltaic module supports.

[0015] The adaptive steering device is installed on the steel frame of the offshore floating photovoltaic platform and includes a steering seat, a steering shaft, a guide connector, and a mounting plate. The steering seat is fixed to the steel frame of the platform, the steering shaft is arranged vertically, and the mounting plate is fixedly connected to the guide connector.

[0016] The mooring force regulation and energy recovery device is mounted on the directional adaptive guide device and includes a drive shaft, sprocket, bearing assembly, coupling, generator assembly, chain, and connecting shackle assembly. The drive shaft is rotatably supported on the mounting plate of the directional adaptive guide device 2 via the bearing assembly, allowing the guide connector, mounting plate, and mooring force regulation and energy recovery device to rotate as a whole around the steering shaft relative to the steering seat. The sprocket is fixedly mounted on the drive shaft, and the chain is wound around the sprocket and meshes with the sprocket teeth. The chain includes a counterweight side segment and a mooring side segment. The counterweight side segment is connected to the counterweight sling via a counterweight side connecting shackle, and the mooring side segment is connected to the mooring cable via a mooring side connecting shackle. When the horizontal force direction of the mooring cable changes, the guide connector, under the traction of the mooring cable or the mooring side segment, drives the mounting plate and the mooring force regulation and energy recovery device to deflect synchronously, ensuring that the mooring cable or the mooring side segment maintains the same force transmission direction as the sprocket.

[0017] The generator assembly includes a generator, a generator mounting base, and a generator shaft. The generator is fixed to the mounting plate of the direction-adaptive guide device via the generator mounting base, and the generator shaft is connected to the drive shaft via a coupling. When the chain drives the sprocket to rotate, the sprocket drives the drive shaft and the generator shaft to rotate synchronously, thereby generating electrical energy and electromagnetic torque.

[0018] The mooring assembly includes a mooring cable, an anchoring base, and anchoring base lugs. One end of the mooring cable is connected to the mooring side chain segment, and the other end is connected to the anchoring base via the anchoring base lugs.

[0019] The counterweight compensation assembly includes a counterweight sling, a counterweight block, and a counterweight block lug. One end of the counterweight sling is connected to the counterweight side chain segment, and the other end is connected to the counterweight block through the counterweight block lug.

[0020] The monitoring and control system includes a tension sensor, a speed sensor, an angle sensor, a counterweight displacement sensor, a controller, a generator load adjustment module, a rectifier module, an energy storage unit, and a communication module. The tension sensor, speed sensor, angle sensor, and counterweight displacement sensor are each connected to the controller. The communication module is used to input platform motion information of the offshore floating photovoltaic platform to the controller. The controller adjusts the electromagnetic damping of the generator through the generator load adjustment module. Based on the mooring side tension, transmission speed, sprocket angle, counterweight displacement, and platform motion information, the controller determines the relative displacement of the chain and the remaining adjustment stroke, and changes the electromagnetic damping of the generator through the generator load adjustment module.

[0021] Under the continuous action of waves, the offshore floating photovoltaic platform undergoes periodic or quasi-periodic reciprocating motion relative to its anchored foundation, causing the chain to repeatedly form release-recovery cycles, driving the generator to rotate bidirectionally. The controller composes one or more complete release-recovery cycles into evaluation periods, extracting at least one displacement characteristic quantity from the previous evaluation period, including the displacement amplitude, root mean square value, maximum absolute value, center offset, or over-limit time percentage of the chain's relative displacement, counterweight displacement, or platform displacement. When the displacement characteristic quantity of the previous evaluation period is lower than the lower limit of the preset target range, the controller reduces the target electromagnetic damping for the next evaluation period to fully utilize the compensation stroke of the chain and counterweight; when the displacement characteristic quantity is higher than the upper limit of the preset target range, the controller increases the target electromagnetic damping for the next evaluation period to reduce the motion amplitude of subsequent release and recovery cycles; when the displacement characteristic quantity is within the preset target range, the current target electromagnetic damping is maintained. Within the same evaluation period, the generator applies reverse electromagnetic torque to both the release and recovery movements of the chain according to the determined target electromagnetic damping and continuously recovers energy; when the displacement, speed, or mooring tension approaches the safety limit, the controller performs protective damping adjustment.

[0022] The electrical energy generated by the generator is converted by the rectifier module and then delivered to the energy storage unit. The energy storage unit can power the monitoring and control system as well as other low-power devices on the offshore floating photovoltaic platform.

[0023] It should be noted that the adaptive direction guiding device and mooring force regulation and energy recovery device do not need to be installed at all mooring positions of the offshore floating photovoltaic platform. For offshore floating photovoltaic platforms using multi-point mooring, the mooring force regulation and energy recovery device can be installed at all mooring positions, or it can be installed only at some mooring positions where the force is greater, the movement is more obvious, or there is a higher potential for energy recovery, while the conventional mooring system continues to be used at other mooring positions.

[0024] The conventional mooring system provides basic restoring force and positioning constraints for the offshore floating photovoltaic platform through changes in the geometry of the mooring cable, axial elongation, or both. The conventional mooring system still allows the platform to move within its design range; therefore, the mooring position equipped with mooring force regulation and energy recovery devices will still shift back and forth relative to the corresponding anchoring foundation, thereby driving the chain, counterweight, and generator assembly.

[0025] By combining the above arrangements, a multi-point coordinated mooring system can be formed, consisting of "basic positioning of conventional mooring system - controlled displacement and load reduction in some key mooring directions - electromagnetic damping limit of generator - energy recovery of platform reciprocating motion". It is not necessary to install the mooring force regulation and energy recovery device at all mooring positions of the platform, which helps to reduce the difficulty of engineering modification and the cost of device configuration.

[0026] This invention also provides a method for regulating mooring force and recovering energy on a floating photovoltaic platform at sea, comprising the following steps:

[0027] The data collection includes the mooring side tension, transmission speed, sprocket angle, and counterweight displacement at the mooring position where the aforementioned adaptive guidance device and mooring force control and energy recovery device are installed, and the platform displacement and direction of motion of the offshore floating photovoltaic platform are obtained.

[0028] The relative displacement of the chain relative to the initial position is determined based on the pitch circle radius of the sprocket and the sprocket rotation angle, and the remaining adjustment stroke is determined based on the difference between the maximum allowable displacement of the chain and the absolute value of the current relative displacement.

[0029] The chain release-recovery cycle is identified based on the chain's direction of motion and relative displacement changes. One or more complete release-recovery cycles are combined into an evaluation period, and displacement characteristics of the chain's relative displacement, counterweight displacement, or platform displacement within the previous evaluation period are extracted.

[0030] When the displacement characteristic is lower than the lower limit of the preset target range, the target electromagnetic damping for the next evaluation period is reduced; when the displacement characteristic is higher than the upper limit of the preset target range, the target electromagnetic damping for the next evaluation period is increased; when the displacement characteristic is within the preset target range, the current target electromagnetic damping is maintained.

[0031] During the next evaluation period, the generator is controlled to apply electromagnetic damping opposite to the direction of movement to both the release and retraction of the chain according to the target electromagnetic damping, and the electrical energy generated by the generator driven by the reciprocating motion of the chain is rectified by the rectifier module and then sent to the energy storage unit.

[0032] When the relative displacement of the chain, the displacement of the counterweight, the displacement of the platform, the transmission speed, or the tension on the mooring side approaches the corresponding safety limit or an abnormality occurs, protective damping adjustment is performed.

[0033] Furthermore, the evaluation period includes one or more complete chain release-recovery cycles; the displacement characteristics include at least one of the following: chain relative displacement, counterweight displacement, or platform displacement amplitude, root mean square value, maximum absolute value, center offset, and the percentage of time exceeding a preset displacement value.

[0034] During the same evaluation period, the target electromagnetic damping remains unchanged or within a preset allowable fluctuation range. The generator generates electromagnetic torque opposite to the direction of chain movement during both the release and retraction of the chain, and recovers mechanical energy from the bidirectional reciprocating motion.

[0035] Furthermore, when the relative displacement of the chain, the displacement of the counterweight, or the displacement of the platform reaches the corresponding safe displacement threshold, or when the transmission speed reaches the preset speed threshold, the present invention increases the electromagnetic damping of the generator to limit the movement; when the mooring side tension reaches the preset tension threshold, the remaining adjustment stroke is greater than the preset safe stroke, and the relative displacement of the chain, the displacement of the counterweight, and the displacement of the platform have not reached the corresponding safe displacement threshold, the present invention decreases the current electromagnetic damping of the generator or limits the current electromagnetic damping from increasing further, so as to release the compensation displacement.

[0036] Compared with the prior art, the present invention has the following beneficial effects in terms of mooring unloading, displacement control, energy utilization and engineering adaptability.

[0037] 1. Achieving controlled displacement and load reduction. This invention utilizes chains, sprockets, and counterweight compensation components to provide additional displacement space for a selected mooring direction. This allows some of the relative displacement between the platform and the anchorage foundation to be borne by chain movement and counterweight lifting, reducing the instantaneous effective elongation of the mooring cable. Compared to simply increasing damping or stiffness, this invention can mitigate mooring force growth and reduce peak tension while preserving necessary motion compliance.

[0038] 2. Balancing Load Reduction Capacity and Displacement Safety. This invention uses one or more complete chain release-recovery cycles to constitute an evaluation period. Based on the response characteristics of the chain's relative displacement, counterweight displacement, or platform displacement in the previous evaluation period, the target electromagnetic damping for the next evaluation period is periodically updated. When the displacement characteristic is below the lower limit of the preset target range, the target electromagnetic damping is reduced to fully utilize the available compensation stroke of the chain and counterweight compensation components; when the displacement characteristic is above the upper limit of the preset target range, the target electromagnetic damping is increased to reduce the motion amplitude of subsequent release and recovery cycles; when the displacement characteristic is within the preset target range, the current damping is maintained. This method avoids frequent switching of generator damping during a single wave release and recovery process, and limits the displacement of the chain, counterweight, and platform while retaining necessary motion compliance.

[0039] 3. Achieve energy recovery from mooring reciprocating motion. The reciprocating motion of the chain drives the generator to rotate bidirectionally via sprockets, drive shafts, and couplings, converting some of the mechanical energy contained in the platform's movement, counterweight lifting, and chain return into electrical energy. The recovered electrical energy is processed by a rectifier module and stored in an energy storage unit, which can be used to power the monitoring and control system or other low-power devices on the platform.

[0040] 4. The generator combines energy conversion and adjustable damping functions. The generator assembly not only functions as a power generation device, but its electromagnetic torque also acts as adjustable damping for the sprocket motion. By changing the generator load, the generator's electromagnetic damping can be continuously adjusted without changing the mechanical structure, allowing the energy recovery process to directly participate in mooring force and displacement control, thus improving the system's functional integration.

[0041] 5. Modular layout suitable for partial mooring locations. This system does not require the installation of adaptive direction guidance devices and mooring force regulation and energy recovery devices at all mooring locations of the floating photovoltaic platform. Depending on project needs, these devices can be installed only in key mooring directions, while conventional mooring systems continue to be used in other locations. This approach retains the reliable basic positioning and wide applicability of conventional mooring systems, while adding directional tracking, displacement regulation, and energy recovery capabilities in areas with higher stress. It is suitable for new platforms and the retrofitting of existing mooring systems.

[0042] 6. Comprehensive monitoring variables and identifiable control status. Through tension sensors, speed sensors, angle sensors, counterweight displacement sensors, and platform motion information, it can obtain mooring forces, sprocket speed, chain relative displacement, counterweight displacement, and overall platform offset in real time, providing a basis for reclamation and retrieval cycle identification, target electromagnetic damping updates, and safety protection.

[0043] 7. Centralized structure and easy maintenance. The sprockets, drive shafts, bearing assemblies, and generator assemblies are centrally arranged on the mounting plate of the adaptive directional guide device. The core mechanical and electrical components are located above the water surface or in easily accessible positions, which facilitates inspection, lubrication, replacement, and troubleshooting, reducing the workload of underwater maintenance.

[0044] 8. Wide parameter adaptability range. This system can be adapted to different platform sizes, water depths, mooring types, permissible offsets, and environmental load levels by adjusting the counterweight mass, chain length, sprocket pitch circle radius, drive shaft size, generator rated torque, and generator load adjustment range.

[0045] 9. Suitable for large-scale modular floating photovoltaic arrays. For large platforms composed of multiple floating units, multiple sets of directional adaptive guidance devices and mooring force regulation and energy recovery devices can be arranged along different edges. Each device can be controlled independently or connected to the platform's central control system for coordinated regulation, and the generated electricity can be stored separately or collected into a common energy storage system, which has good scalability and engineering application value.

[0046] 10. The overall chain entry direction of the device can be dynamically adapted. The direction-adaptive guiding device is connected to the platform steel frame, and the mooring force regulation and energy recovery device is installed on the direction-adaptive guiding device. The chain entry path of sprocket 32 ​​and the force transmission direction on the mooring side can better adapt to the angle changes of the mooring cable under multi-directional environmental loads, thereby reducing the lateral off-center loads on the drive shaft, bearing assembly, generator mounting base and connecting shackle assembly. Attached Figure Description

[0047] Figure 1Schematic diagram of the overall structure of a floating photovoltaic platform and its mooring force control and energy recovery system;

[0048] Figure 2 Partial schematic diagram of the installation relationship between the adaptive direction guidance device and the mooring force control and energy recovery device;

[0049] Figure 3 Schematic diagram of the direction adaptive guidance device; where Figure 3 a is a side view. Figure 3 b is an axonometric drawing. Figure 3 c is the top view.

[0050] Figure 4 Schematic diagram of a single mooring force control and energy recovery device;

[0051] Figure 5 Enlarged view of a portion of the transmission assembly;

[0052] Figure 6 Block diagram of monitoring and control system principle;

[0053] Figure 7 Flowchart of mooring force control and energy recovery methods;

[0054] Legend: 1. Floating photovoltaic platform; 11. Floating body unit; 12. Photovoltaic module; 13. Photovoltaic module support; 14. Floating body connector; 15. Platform steel frame; 2. Direction adaptive guidance device; 21. Steering seat; 22. Steering shaft; 23. Guide connector; 24. Mounting plate; 3. Mooring force regulation and energy recovery device; 31. Drive shaft; 32. Sprocket; 321. Sprocket body; 322. Sprocket tooth; 33. Bearing assembly; 331. Bearing; 332. Bearing seat; 34. Coupling; 35. Generator assembly; 351. Generator; 352. Generator mounting base; 353. Generator rotor 36. Shaft; 361. Chain; 362. Counterweight side chain segment; 363. Mooring side chain segment; 37. Connecting shackle assembly; 371. Counterweight side connecting shackle; 372. Mooring side connecting shackle; 4. Mooring assembly; 41. Mooring cable; 42. Anchorage foundation; 43. Anchorage foundation lug; 5. Counterweight compensation assembly; 51. Counterweight sling; 52. Counterweight block; 53. Counterweight block lug; 61. Tension sensor; 62. Speed ​​sensor; 63. Angle sensor; 64. Counterweight displacement sensor; 65. Controller; 66. Generator load regulation module; 67. Rectifier module; 68. Energy storage unit; 69. Communication module. Detailed Implementation

[0055] The technical solutions in the embodiments of the present invention will be further described clearly and completely below with reference to the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Modifications, substitutions, or combinations made by those skilled in the art based on the disclosure of the present invention without creative effort should all fall within the scope of protection of the present invention.

[0056] Reference Figures 1 to 7 This invention proposes a system and method for mooring force regulation and energy recovery of a floating photovoltaic platform based on adjustable electromagnetic damping. The system mainly consists of a floating photovoltaic platform 1, a direction adaptive guidance device 2, a mooring force regulation and energy recovery device 3, a mooring component 4, a counterweight compensation component 5, and a monitoring and control system.

[0057] The offshore floating photovoltaic platform 1 includes multiple floating units 11, photovoltaic modules 12, photovoltaic module supports 13, floating connectors 14, and a platform steel frame 15. The multiple floating units 11 are arranged in a predetermined array, and adjacent floating units 11 are connected by floating connectors 14 to form a floating photovoltaic array capable of supporting the photovoltaic modules 12 and adapting to sea surface movements. The photovoltaic modules 12 are mounted on the upper part of the floating units 11 or the platform steel frame 15 via the photovoltaic module supports 13.

[0058] The platform steel frame 15 is located on the upper part and edge of the floating body unit 11, and is used to support the photovoltaic module bracket 13, photovoltaic module 12, directional adaptive guidance device 2, and mooring force regulation and energy recovery device 3. The platform steel frame 15 can be made of shaped steel, steel pipe, channel steel, aluminum alloy profile, or other structures that can meet the requirements of load-bearing, corrosion resistance and fatigue in marine environments.

[0059] Reference Figure 1 The floating photovoltaic platform 1 adopts a multi-point mooring method. Figure 1 The diagram illustrates that a set of adaptive direction guidance device 2 and a set of mooring force regulation and energy recovery device 3 are respectively set at two opposite mooring positions on the platform. Each set of mooring force regulation and energy recovery device 3 is connected to the platform steel frame 15 through the corresponding adaptive direction guidance device 2, and is connected to the corresponding mooring component 4 and counterweight compensation component 5.

[0060] It should be noted that the adaptive direction guiding device 2 and the mooring force regulation and energy recovery device 3 of the present invention are not required to be installed at all mooring positions of the floating photovoltaic platform 1, nor are they required to completely replace the platform's original mooring system. In actual engineering, the mooring force regulation and energy recovery device 3 can be installed at one or more selected mooring positions according to the dominant wave direction, the platform's main direction of motion, the magnitude of the force at different mooring positions, the installation space of the platform's steel frame 15, and the energy recovery requirements, while the conventional mooring system continues to be used at other mooring positions.

[0061] For mooring locations where the mooring force regulation and energy recovery device 3 is not installed, conventional mooring cables can be used to directly connect the offshore floating photovoltaic platform 1 and the corresponding anchoring foundation. The conventional mooring system provides foundation restoring force and positioning constraints for the offshore floating photovoltaic platform 1 through changes in the geometric configuration of the mooring cable, axial elongation, or both.

[0062] See also the appendix. Figure 4 The mooring position equipped with the mooring force regulation and energy recovery device 3 provides additional controlled displacement, adjustable electromagnetic damping and energy recovery functions through the chain 36, sprocket 32, counterweight compensation component 5 and generator component 35.

[0063] Although other mooring locations on the platform employ conventional mooring systems, these systems do not completely secure the floating photovoltaic platform 1. Under the influence of waves, wind, and currents, the platform will still experience swaying, rolling, heeling, pitching, rolling, and bowing motions within design limits. Therefore, the location where the mooring force regulation and energy recovery device 3 is installed will still experience reciprocating displacement relative to the corresponding anchoring foundation 42. This reciprocating displacement can drive the chain 36, sprocket 32, and generator assembly 35, thereby achieving mooring force regulation and mechanical energy recovery.

[0064] Therefore, the mooring position equipped with the mooring force regulation and energy recovery device 3 can form a multi-point cooperative mooring system together with other mooring positions using conventional mooring systems. The conventional mooring system undertakes the basic positioning and overall restoration of the platform, while the mooring force regulation and energy recovery device 3 provides locally controlled compliance, electromagnetic damping adjustment, and energy recovery functions in the selected mooring direction, forming a cooperative working mode of "multi-point mooring basic positioning—local displacement release and load reduction—electromagnetic damping limiting displacement—reciprocating motion energy recovery".

[0065] The mooring assembly 4 includes a mooring cable 41, an anchoring base 42, and an anchoring base lugs 43. One end of the mooring cable 41 is connected to the mooring side of the mooring force regulation and energy recovery device 3, and the other end is connected to the anchoring base 42 located on the seabed. The anchoring base lugs 43 are fixedly installed on the upper part of the anchoring base 42. The mooring cable 41 is connected to the anchoring base lugs 43 through shackles, pins, or other connecting components, thereby forming a force transmission path of "floating photovoltaic platform - mooring force regulation and energy recovery device - mooring cable - anchoring base".

[0066] The anchoring foundation 42 can be a gravity anchor, pile anchor, suction anchor, embedded anchor, or other anchoring structure suitable for offshore floating photovoltaic platforms, depending on seabed geological conditions, water depth, mooring load, and platform dimensions. The mooring cable 41 can be an anchor chain, wire rope, synthetic fiber cable, or a combination mooring cable composed of different types of cables.

[0067] The counterweight compensation component 5 includes a counterweight sling 51, a counterweight block 52, and a counterweight block lug 53. The counterweight block lug 53 is fixedly installed on the upper part of the counterweight block 52. The lower end of the counterweight sling 51 is connected to the counterweight block lug 53, and the upper end of the counterweight sling 51 is connected to the counterweight side of the mooring force regulation and energy recovery device 3.

[0068] The counterweight 52 can be made of metal, concrete, a water-filled tank, or a composite counterweight structure made of multiple materials. The mass of the counterweight 52 can be determined based on the initial force of the mooring system, the allowable offset of the platform, the allowable travel of the chain 36, the load variation range of the mooring cable 41, and the damping adjustment capability of the generator assembly 35.

[0069] It should be noted that the function of the counterweight 52 is not to keep the mooring force constant throughout the entire process. The counterweight 52 mainly utilizes its gravity, inertia, and available lifting stroke to provide the chain 36 with basic tension and additional displacement space, so that the mooring direction, which is equipped with the mooring force regulation and energy recovery device 3, can generate appropriate displacement when the platform moves, thereby reducing the excessive constraint of the mooring system.

[0070] When the floating photovoltaic platform 1 moves away from the corresponding anchoring foundation 42, the mooring cable 41 pulls the chain 36 to move, and the counterweight 52 undergoes vertical displacement along with the counterweight sling 51. The movement of the chain 36 can absorb part of the relative displacement between the platform and the anchoring foundation 42, thereby reducing the direct conversion of this relative displacement into the tension of the mooring cable 41 or the rapid change of the mooring alignment, which helps to reduce the growth rate and peak value of the mooring force.

[0071] Reference Figure 2 and Figure 3The adaptive steering device 2 includes a steering seat 21, a steering shaft 22, a guide connector 23, and a mounting plate 24. The steering seat 21 serves as the mounting base between the platform steel frame 15 and the mooring force regulation and energy recovery device 3. The steering seat 21 is fixed to the platform steel frame 15, the steering shaft 22 is arranged vertically, and the mounting plate 24 is connected to the guide connector 23 and is used to support the bearing housing 332, generator mounting base 352, and other mounting components of the mooring force regulation and energy recovery device 3.

[0072] The guide connector 23 is fixedly connected to the mounting plate 24 and can rotate relative to the steering seat 21 around the steering shaft 22 with the mounting plate 24. When the platform movement causes the horizontal force direction of the mooring cable 41 to change, the direction adaptive guide device 2 adjusts the mooring side chain entry path accordingly, thereby reducing the lateral load caused by the rigid fixed direction of the mooring force regulation and energy recovery device 3.

[0073] Reference Figure 4 and Figure 5 The mooring force regulation and energy recovery device 3 includes a drive shaft 31, a sprocket 32, a bearing assembly 33, a coupling 34, a generator assembly 35, a chain 36, and a connecting shackle assembly 37.

[0074] The bearing assembly 33 includes a bearing 331 and a bearing housing 332. The bearing housing 332 is fixedly mounted on the mounting plate 24 of the direction adaptive guide device 2, and the bearing 331 is mounted inside the bearing housing 332. The drive shaft 31 passes through the bearing 331 and is able to rotate relative to the bearing housing 332 under the support of the bearing 331.

[0075] In this embodiment, two bearing assemblies 33 are provided and arranged axially at intervals along the drive shaft 31, with the sprocket 32 ​​disposed between the two bearing assemblies 33. The two bearing assemblies 33 respectively provide support for the drive shaft 31 on both sides of the sprocket 32, which can reduce the radial offset and bending deformation of the sprocket 32 ​​under the tension of the chain 36, and improve the working stability of the transmission assembly.

[0076] Reference Figure 5 The sprocket 32 ​​includes a sprocket body 321 and sprocket teeth 322 arranged circumferentially along the sprocket body 321. The sprocket body 321 is fixedly sleeved on the drive shaft 31 and rotates synchronously with the drive shaft 31. The sprocket body 321 and the drive shaft 31 can be connected by a key, spline, interference fit, expansion sleeve, bolt, or welding.

[0077] The tooth profile and pitch of the sprocket tooth 322 are matched with those of the chain 36, so that the chain 36 can stably mesh with the sprocket 32 ​​during reciprocating motion, and avoid significant slippage of the chain 36 relative to the sprocket 32.

[0078] The chain 36 is wound around a portion of the circumference of the sprocket 32. The side of the chain 36 that faces vertically downward is the counterweight side chain segment 361, and the side of the chain 36 that faces obliquely toward the anchoring foundation 42 is the mooring side chain segment 362.

[0079] The counterweight-side chain segment 361 is connected to the counterweight sling 51 via the counterweight-side connecting shackle 371, and the mooring-side chain segment 362 is connected to the mooring cable 41 via the mooring-side connecting shackle 372. The counterweight-side connecting shackle 371 and the mooring-side connecting shackle 372 together constitute the connecting shackle assembly 37.

[0080] The connecting shackle assembly 37 can be an arc-shaped shackle, a straight shackle, a swivel shackle, a pin connector, or a universal connector. By setting the connecting shackle assembly 37, a reliable connection can be achieved between the chain 36 and the counterweight sling 51 and the mooring cable 41, and the installation, replacement, and maintenance of each flexible component can be facilitated, while reducing local bending, torsion, and wear at the connection points of different flexible components.

[0081] Chain 36 may be a roller chain, plate chain, short link chain, lifting chain, or other flexible transmission component capable of meshing with sprocket 32 ​​and bearing reciprocating tensile force. Chain 36 and sprocket 32 ​​may be made of stainless steel, high-strength alloy steel, or marine-resistant steel to adapt to high humidity, high salt spray, and seawater splash environments.

[0082] The generator assembly 35 includes a generator 351, a generator mounting base 352, and a generator shaft 353. The generator 351 is fixedly mounted on the mounting plate 24 of the direction adaptive guide device 2 via the generator mounting base 352. The generator shaft 353 is connected to the drive shaft 31 via a coupling 34. When the chain 36 drives the sprocket 32 ​​to rotate, the rotation of the drive shaft 31 can be transmitted to the generator shaft 353. The sprocket 32 ​​drives the drive shaft 31 and the generator shaft 353 to rotate synchronously, thereby enabling the generator 351 to generate electrical energy and electromagnetic torque.

[0083] The coupling 34 can be a flexible coupling, diaphragm coupling, gear coupling, plum blossom coupling, or other coupling structures that can transmit bidirectional torque and compensate for certain installation errors.

[0084] Reference Figure 4 and Figure 5 In this embodiment, a generator assembly 35 is connected to each end of the drive shaft 31. The two generator assemblies 35 are fixed to the mounting plate 24 of the direction adaptive guide device 2 by corresponding generator mounting seats 352. The two generators 351 can be put into operation simultaneously, or one of the generators 351 can be selected to operate or both generators 351 can operate together, depending on the rotational speed of the sprocket 32, the mooring side tension, the state of charge of the energy storage unit 68, and the required electromagnetic damping.

[0085] In other embodiments, a generator assembly 35 may be provided only at one end of the drive shaft 31, with an end support structure or protective structure provided at the other end of the drive shaft 31. The variation in the number of generator assemblies 35 does not alter the fundamental principle of this invention: adjusting the sprocket's motion resistance via the electromagnetic torque of the generator.

[0086] The generator 351 can be a permanent magnet synchronous generator, a permanent magnet DC generator, an asynchronous generator, or other rotating electric motors that can convert energy and generate electromagnetic damping torque under bidirectional reciprocating rotation conditions.

[0087] When the floating photovoltaic platform 1 is subjected to waves, wind, and ocean currents and moves away from the anchoring foundation 42, the mooring cable 41 pulls the mooring side chain segment 362 to move. The mooring side chain segment 362 drives the sprocket 32 ​​to rotate, and the sprocket 32 ​​further drives the drive shaft 31 to rotate. The drive shaft 31 drives the generator shaft 353 to rotate through the coupling 34, so that the generator 351 generates electrical energy and electromagnetic torque.

[0088] During the aforementioned traction process, if the mooring cable 41 changes its horizontal angle relative to the platform steel frame 15 due to platform sway, bow roll, or changes in the direction of environmental load, the mooring cable 41 or the mooring side chain segment 362 first acts on the guide connector 23. The guide connector 23 drives the mounting plate 24 and its bearing assembly 33, sprocket 32, drive shaft 31, and generator assembly 35 to deflect around the steering shaft 22 as a whole, so that the chain entry direction of the sprocket 32 ​​is adapted to the actual force direction.

[0089] Meanwhile, the counterweight chain segment 361 drives the counterweight block 52 to move vertically through the counterweight side connecting shackle 371 and counterweight sling 51. Therefore, the mechanical energy corresponding to the relative motion between the offshore floating photovoltaic platform 1 and the anchoring foundation 42 is partly converted into the gravitational potential energy and kinetic energy of the counterweight block 52, and the other part is transmitted to the generator 351 through the sprocket 32, drive shaft 31 and coupling 34, and converted into electrical energy.

[0090] When the floating photovoltaic platform 1 returns to its equilibrium position, the counterweight 52 moves in the opposite direction under the action of gravity, causing the counterweight-side chain segment 361, sprocket 32, and drive shaft 31 to rotate in the opposite direction. The generator 351 can also generate electrical energy during the reverse rotation process, and form electromagnetic damping on the reverse movement of the transmission system, thereby suppressing the rapid rebound of the counterweight 52 and chain 36.

[0091] It is important to note that the generator assembly 35 of this invention is not only used for energy recovery, but the electromagnetic torque it generates is also used to regulate the motion of the sprocket 32, chain 36, and counterweight 52. The core of this invention's load reduction mechanism lies in allowing the chain 36 and counterweight 52 to produce appropriate displacement, thereby increasing the motion compliance in the mooring direction of the platform equipped with the mooring force regulation and energy recovery device 3, and reducing excessive stretching of the mooring cable 41 by the platform's motion. The adjustable electromagnetic damping generated by the generator 351 is mainly used to control the movement speed and maximum displacement of the chain 36 and counterweight 52, enabling the system to coordinate load reduction by allowing displacement and preventing excessive displacement.

[0092] Reference Figure 5 Let the tension of the mooring side chain segment 362 be T1, the tension of the counterweight side chain segment 361 be T2, the pitch circle radius of the sprocket 32 ​​be r, and the equivalent moment of inertia of the drive shaft 31, sprocket 32, coupling 34, and generator rotor referred to the drive shaft 31 be J. eq The angular velocity of sprocket 32 ​​is ω.

[0093] Taking the direction of rotation of the traction sprocket 32 ​​on the mooring side chain segment 362 as the positive direction, the rotational dynamics of the transmission system can be expressed as follows:

[0094]

[0095] In the formula, B eq M represents the equivalent viscous damping coefficient of the bearing assembly 33, coupling 34, and generator assembly 35, referred to the drive shaft 31. f (ω) represents the mechanical friction torque; M e (t) represents the adjustable electromagnetic torque generated by generator 351.

[0096] To facilitate the establishment of a dynamic model of the system in a single mooring direction, it is assumed that the counterweight 52, under the constraint of the guiding mechanism, only performs translational motion in the vertical direction, neglecting its lateral oscillation and rotation. Taking the vertically upward direction of the counterweight 52 as the positive direction, the dynamic relationship of the counterweight 52 is as follows:

[0097]

[0098] Therefore, we can conclude that:

[0099]

[0100] In the formula, m c For the mass of counterweight 52, y c This represents the vertical displacement of counterweight 52.

[0101] As can be seen from the above relationships, the mooring side tension T1 is affected not only by the gravity of the counterweight 52, but also by the inertia of the counterweight 52, the rotational inertia of the transmission system, mechanical damping, and the electromagnetic torque of the generator. Therefore, there can be a difference in tension on both sides of the chain 36 during system operation, and this tension difference can be adjusted by the load state of the generator assembly 35.

[0102] When there is no significant slippage between chain 36 and sprocket 32, the moving speed v of chain 36, the relative displacement s, the angular velocity ω of sprocket 22, and the rotation angle θ relative to the initial position satisfy the following:

[0103]

[0104]

[0105] When the platform movement puts tension on the mooring cable 41, the sprocket 32 ​​rotates and releases the chain 36 towards the mooring side. The resulting displacement s can compensate for the mooring displacement caused by the platform movement. Therefore, with sufficient remaining travel on the chain 36, the system can reduce the tensile deformation of the mooring cable 41 and delay the increase in mooring tension.

[0106] For a permanent magnet generator, its induced electromotive force and electromagnetic torque can be expressed as follows:

[0107]

[0108]

[0109] In the formula, K e K is the back electromotive force coefficient. t is the electromagnetic torque coefficient, and i is the generator current.

[0110] When regulating using an equivalent load, the generator's electromagnetic torque can be expressed as:

[0111]

[0112] In the formula, R g R is the equivalent internal resistance of generator 351. L The equivalent external load formed by the generator load regulation module 66.

[0113] Therefore, the equivalent electromagnetic damping coefficient of the generator is:

[0114]

[0115] The electromagnetic damping coefficient C of the generator 351 can be changed by altering the equivalent external load, current command, or power electronic conversion parameters. eThis adjusts the motion resistance of the sprocket 32.

[0116] Reference Figure 6 The monitoring and control system provided in this invention includes a tension sensor 61, a speed sensor 62, a rotation angle sensor 63, a counterweight displacement sensor 64, a controller 65, a generator load adjustment module 66, a rectifier module 67, an energy storage unit 68, and a communication module 69.

[0117] Tension sensor 61 is installed on mooring side chain segment 362, mooring side connecting shackle 372 or mooring cable 41 to monitor real-time mooring side tension in the mooring direction where mooring force regulation and energy recovery device 3 is installed.

[0118] The speed sensor 62 is located at the drive shaft 31, sprocket 32 ​​or generator shaft 353 to monitor the real-time speed of the transmission system and indirectly obtain the movement speed of the chain 36 and counterweight 52.

[0119] Angle sensor 63 is installed on drive shaft 31, sprocket 32 ​​or generator shaft 353 to monitor the angle of rotation of sprocket 32 ​​relative to the initial position and to calculate the relative displacement of chain 36 relative to the initial position based on the pitch circle radius of sprocket 32.

[0120] In one embodiment, the speed sensor 62 and the angle sensor 63 are respectively provided; in another embodiment, the same set of rotary encoders can be used to obtain the speed and angle information of the transmission system at the same time.

[0121] The counterweight displacement sensor 64 is used to monitor the vertical displacement of the counterweight 52 relative to its initial position and the remaining travel of the counterweight compensation component 5. The counterweight displacement sensor 64 can be a drawstring displacement sensor, a laser rangefinder, an ultrasonic rangefinder, a magnetostrictive displacement sensor, or other displacement measurement devices suitable for marine environments.

[0122] Tension sensor 61, speed sensor 62, angle sensor 63, and counterweight displacement sensor 64 are respectively connected to controller 65. Controller 65 receives monitoring data collected by each sensor and performs filtering, outlier identification, and operational status judgment on the monitoring data.

[0123] The communication module 69 communicates bidirectionally with the controller 65 to transmit mooring side tension, transmission system speed, chain relative displacement, counterweight displacement, power generation and energy storage status to the monitoring system of the offshore floating photovoltaic platform 1.

[0124] The communication module 69 can also receive the platform's horizontal displacement, speed, and direction of motion measured by the platform's existing satellite positioning system, inertial measurement system, or motion monitoring system, and transmit the platform's motion information to the controller 65. Therefore, it is not necessary to add a separate platform displacement sensor to this system, and the overall platform offset can be used as the basis for electromagnetic damping adjustment.

[0125] The controller 65 is connected to the generator load regulation module 66. The generator load regulation module 66 changes the equivalent electrical load, current, output power or power electronic conversion parameters of the generator 351 according to the control commands issued by the controller 65, thereby regulating the electromagnetic torque generated by the generator 351.

[0126] The generator load regulation module 66 may include one or more of the following: an adjustable resistor, a power electronic load, a controllable rectifier, a DC / DC converter, an inverter, or a controllable switching circuit.

[0127] The power output terminal of the generator assembly 35 is connected to the rectifier module 67, which is connected to the energy storage unit 68. The rectifier module 67 is used to convert the alternating current or polarity-changing electrical energy generated by the generator 351 during bidirectional reciprocating rotation into direct current suitable for the energy storage unit 68 to receive.

[0128] The energy storage unit 68 can be a battery, a supercapacitor, or a hybrid energy storage device consisting of a battery and a supercapacitor. The electrical energy stored in the energy storage unit 68 can be used to power the tension sensor 61, the speed sensor 62, the angle sensor 63, the counterweight displacement sensor 64, the controller 65, and the communication module 69, and can also be used for other low-power devices on the offshore floating photovoltaic platform 1.

[0129] Reference Figure 7 The mooring force control and energy recovery method of the present invention does not use the instantaneous displacement change during a single wave release and recovery process as the basis for normal damping switching. Instead, it identifies the release-recovery cycle formed by the chain 36 under continuous wave action, and combines one or more complete release and recovery cycles into an evaluation period. Based on the displacement response characteristics of the previous evaluation period, the target electromagnetic damping of the next evaluation period is periodically updated.

[0130] After system startup, controller 65 acquires the mooring side tension via tension sensor 61, the angular velocity of the transmission system via speed sensor 62, the rotation angle of sprocket 32 ​​relative to its initial position via angle sensor 63, and the vertical displacement of counterweight 52 via counterweight displacement sensor 64. Controller 65 calculates the relative displacement of chain 36 based on the rotation angle of sprocket 32.

[0131]

[0132] And calculate the remaining adjustment stroke based on the maximum permissible movement distance of chain 36:

[0133]

[0134] In the formula, s lim The maximum permissible travel distance of chain 36, s rem This represents the remaining adjustment stroke of chain 36.

[0135] The controller 65 identifies the release-retrieval cycle of the chain 36 based on its direction of movement, relative displacement extremes, and the moment the transmission speed crosses zero. A complete release-retrieval cycle is defined as the chain 36 being released from its initial position toward the mooring side and then returning, or moving from a displacement extreme to the opposite displacement extreme and then returning. The evaluation period consists of one or more complete release-retrieval cycles, the length of which can be determined based on the wave period, sea state stability, and control update speed.

[0136] For the kth evaluation period, controller 65 calculates the relative displacement s of the chain and the counterweight displacement y. c and platform displacement x p Extract displacement features. These features may include one or more of the following: displacement amplitude, root mean square value, maximum absolute value, center offset, and the percentage of time exceeding a preset displacement value. Chain relative displacement amplitude A s and displacement center s c They can be represented as:

[0137] ,

[0138] In the formula, s max and s min These represent the maximum and minimum relative displacements of chain 36 during the evaluation period, respectively. Displacement amplitude A s Reflects the range of motion of chain 36 during each extension and retraction under wave action, and the displacement center s c It reflects the shift in working position caused by wind, current, tide, or average drift. The controller 65 can determine the comprehensive displacement characteristic based on at least one of the chain displacement characteristics, counterweight displacement characteristics, and platform displacement characteristics.

[0139] When the comprehensive displacement characteristic value in the previous evaluation period is lower than the lower limit of the preset target range, it indicates that the available compensation stroke of the chain 36 and the counterweight 52 has not been fully utilized. In the next evaluation period, the controller 65 reduces the target electromagnetic damping of the generator 351 to reduce the constraint on the rotation of the sprocket 32, so that the chain extension and retraction amplitude under the subsequent wave action is appropriately increased.

[0140] When the comprehensive displacement characteristic value in the previous evaluation period is higher than the upper limit of the preset target range, it indicates that the motion amplitude of the chain 36, counterweight 52 or floating photovoltaic platform 1 is too large. In the next evaluation period, the controller 65 increases the target electromagnetic damping of the generator 351 to reduce the displacement amplitude of the subsequent launch and recovery cycle and retain the necessary safe travel.

[0141] When the comprehensive displacement characteristic value within the current evaluation period is within the preset target range, the controller 65 maintains the current target electromagnetic damping. To avoid frequent fluctuations in damping between adjacent evaluation periods, the target range can be set with upper and lower boundaries, and can adopt one or more of the following methods: hysteresis interval, confirmation over multiple consecutive evaluation periods, or damping change rate limitation.

[0142] During the same evaluation period, generator 351 operates according to the determined target electromagnetic damping. Chain 36 drives generator 351 to rotate during both deployment and retrieval. Generator 351 generates electromagnetic torque opposite to the direction of motion in both directions, and transmits the mechanical energy from the bidirectional reciprocating motion to energy storage unit 68 via rectifier module 67. During normal operation, instantaneous displacement increases or decreases or direction changes during a single deployment or retrieval process are not used as conditions for updating the target damping.

[0143] When the relative displacement of chain 36, the vertical displacement of counterweight 52, or the overall offset of the floating photovoltaic platform 1 reaches the corresponding safe displacement threshold, or when the transmission system speed reaches the preset speed threshold, the controller 65 can temporarily override the current target electromagnetic damping and increase the electromagnetic damping to limit the movement stroke of chain 36 and counterweight compensation component 5 and the platform displacement. When the mooring side tension reaches the preset tension threshold, the remaining adjustment stroke is still greater than the preset safe stroke, and the relative displacement of chain 36, the vertical displacement of counterweight 52, and the overall offset of the floating photovoltaic platform 1 have not reached the corresponding safe displacement threshold, the controller 65 can reduce the current electromagnetic damping or limit its further increase to allow the mooring side chain segment 362 to release the compensation displacement. After the safe state is lifted, the device resumes operation according to the target electromagnetic damping updated during the evaluation period.

[0144] Therefore, this invention establishes a control method of "periodic chain deployment-recovery and bidirectional power generation, multiple complete deployment and recovery cycles forming evaluation periods, updating the target damping for the next evaluation period based on displacement feedback from the previous evaluation period, and implementing rapid protection when approaching safety limits." This method not only utilizes appropriate displacement to improve motion compliance in the mooring direction but also avoids frequent switching of generator damping with each wave deployment and recovery process.

[0145] In practical applications, depending on the platform size, the direction of the main environmental loads, and the force differences at different mooring positions, the direction-adaptive guidance device 2 and the mooring force regulation and energy recovery device 3 can be selected to be installed at all mooring positions, or the direction-adaptive guidance device 2 and the mooring force regulation and energy recovery device 3 can be installed only on the wave-facing side, the dominant force side, the mooring position with greater tension, or the mooring position with greater kinetic energy, while the conventional mooring system continues to be used at the other mooring positions.

[0146] Each mooring force regulation and energy recovery device 3 can be equipped with an independent monitoring and control system, or they can share the platform central controller. The central controller determines the load adjustment commands of each generator assembly 35 according to the tension, relative displacement of the chain, displacement of the counterweight, and the direction of platform movement in different mooring directions, so as to coordinate the force and displacement in each mooring direction.

[0147] The electrical energy generated by each generator assembly 35 can be transmitted to an independent energy storage unit 68, or it can be collected by the rectifier module 67 and then transmitted to a unified energy storage unit 68 via a common DC bus.

[0148] In practical applications, this system can be adapted to different offshore floating photovoltaic platforms through modular parameter adjustments. The mass of the counterweight 52 can be adjusted for different platform dimensions and mooring loads; the effective length of the chain 36, the pitch circle radius of the sprocket 32, and the lifting space of the counterweight 52 can be adjusted for different allowable displacements and adjustment strokes; and generators 351 with different rated torques, rated speeds, and rated power can be selected for different energy recovery and damping adjustment requirements.

[0149] The diameter of the drive shaft 31, the load-bearing capacity of the bearing assembly 33, the meshing parameters of the sprocket 32 ​​and the chain 36, and the adjustment range of the generator load adjustment module 66 can also be adjusted according to actual environmental conditions, so that the system can adapt to different water depths, different sea conditions and different multi-point mooring arrangements.

[0150] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, or combinations 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 system for regulating mooring force and recovering energy on a floating photovoltaic platform at sea, characterized in that, It includes a floating photovoltaic platform (1), a direction adaptive guidance device (2), a mooring force regulation and energy recovery device (3), a mooring component (4), a counterweight compensation component (5), and a monitoring and control system (6). The floating photovoltaic platform (1) includes floating body units (11), photovoltaic modules (12), photovoltaic module brackets (13), floating body connectors (14), and platform steel frame (15). Multiple floating body units (11) are connected by floating body connectors (14) to form a floating photovoltaic array. The photovoltaic modules (12) are mounted on the floating body units (11) or platform steel frame (15) by the photovoltaic module brackets (13). The adaptive direction guiding device (2) is installed on the platform steel frame (15) of the floating photovoltaic platform (1). The adaptive direction guiding device (2) includes a steering seat (21), a steering shaft (22), a guide connector (23), and a mounting plate (24). The steering seat 21 is fixed to the platform steel frame 15, the steering shaft 22 is arranged vertically, and the mounting plate (24) is fixedly connected to the guide connector (23). The mooring force regulation and energy recovery device (3) includes a drive shaft (31), a sprocket (32), a bearing assembly (33), a coupling (34), a generator assembly (35), a chain (36), and a connecting shackle assembly (37); the drive shaft (31) is rotatably mounted on the mounting plate (24) of the direction adaptive guide device (2) via the bearing assembly (33), so that the guide connector (23), the mounting plate (24), and the mooring force regulation and energy recovery device (3) can rotate as a whole around the steering shaft (22) relative to the steering seat (21); the sprocket (32) is fixedly mounted on the drive shaft (31), and the chain (36) is wound around the sprocket (32) and meshes with the sprocket (32); The mooring assembly (4) includes a mooring cable (41) and an anchoring base (42). One end of the mooring cable (41) is connected to a mooring side chain segment (362) provided on the chain (36) via a mooring side connecting shackle (372), and the other end is connected to the anchoring base (42). The counterweight compensation component (5) includes a counterweight sling (51) and a counterweight block (52). One end of the counterweight sling (51) is connected to the counterweight side chain segment (361) of the chain (36) through a counterweight side connecting shackle (371), and the other end is connected to the counterweight block (52). The monitoring and control system (6) includes a tension sensor (61), a speed sensor (62), an angle sensor (63), a counterweight displacement sensor (64), a controller (65), a generator load adjustment module (66), a rectifier module (67), an energy storage unit (68), and a communication module (69). The tension sensor (61), speed sensor (62), angle sensor (63) and counterweight displacement sensor (64) are respectively connected to the controller (65) via signals. The communication module (69) is used to input the platform motion information of the floating photovoltaic platform (1) to the controller (65). The controller (65) adjusts the electromagnetic damping of the generator (351) through the generator load adjustment module (66). The power output terminal of the generator (351) is connected to the energy storage unit (68) via the rectifier module (67).

2. The offshore floating photovoltaic platform mooring force regulation and energy recovery system according to claim 1, characterized in that, The sprocket (32) includes a sprocket body (321) fixedly sleeved on the drive shaft (31) and sprocket teeth (322) arranged circumferentially along the sprocket body (321). The sprocket teeth (322) mesh with the chain (36) to convert the reciprocating linear motion of the chain (36) into the bidirectional rotation of the drive shaft (31).

3. The offshore floating photovoltaic platform mooring force regulation and energy recovery system according to claim 1, characterized in that, The bearing assembly (33) includes a bearing (331) and a bearing housing (332). The bearing housing (332) is fixedly mounted on the mounting plate (24) of the direction adaptive guide device (2), and the bearing (331) is installed inside the bearing housing (332).

4. The offshore floating photovoltaic platform mooring force regulation and energy recovery system according to claim 1, characterized in that, The counterweight sling (51) is connected to the counterweight block (52) via a counterweight lug (53) set on the counterweight block (52), and the mooring cable (41) is connected to the anchoring foundation (42) via an anchoring foundation lug (43) set on the anchoring foundation (42).

5. The offshore floating photovoltaic platform mooring force regulation and energy recovery system according to claim 1, characterized in that, The bearing assembly (33) and generator assembly (35) can be provided in one or two sets. One end of the drive shaft (31) is connected to a set of bearing assembly (33) and generator assembly (35), or both ends of the drive shaft (31) are respectively connected to a set of bearing assembly (33) and generator assembly (35). When both ends of the drive shaft (31) are respectively connected to the bearing assembly (33) and generator assembly (35), the two sets of generator assemblies (35) are configured to operate independently or together. The generator assembly (35) includes a generator (351), a generator mounting base (352), and a generator shaft (353). The generator (351) is fixed to the mounting plate (24) of the direction adaptive guide device (2) via the generator mounting base (352). The generator shaft (353) is connected to the drive shaft (31) via a coupling (34) to generate electrical energy when the chain (36) drives the sprocket (32) to reciprocate, and to apply adjustable electromagnetic damping to the drive shaft (31).

6. The offshore floating photovoltaic platform mooring force regulation and energy recovery system according to claim 1, characterized in that, The adaptive steering device (2) includes a steering seat (21), a vertically arranged steering shaft (22), a guide connector (23) rotatable about the steering shaft (22), and a mounting plate (24) for supporting or connecting the mooring force regulation and energy recovery device (3); the mounting plate (24) is fixedly connected to the guide connector (23), and the mooring force regulation and energy recovery device (3) is mounted on the mounting plate (24), so that the guide connector (23), the mounting plate (24), and the mooring force regulation and energy recovery device (3) are connected together. The mooring force regulation and energy recovery device (3) can rotate as a whole around the steering shaft (22) relative to the steering seat (21); when the horizontal force direction of the mooring cable (41) changes, the guide connector (23) drives the mounting plate (24) and the mooring force regulation and energy recovery device (3) to deflect synchronously under the traction of the mooring cable (41) or the mooring side chain segment (362), so that the mooring cable (41) or the mooring side chain segment (362) and the sprocket (32) maintain the forward force transmission.

7. The offshore floating photovoltaic platform mooring force regulation and energy recovery system according to claim 1, characterized in that, The tension sensor (61) is disposed at least once in one of the mooring side chain segment (362), the mooring side connecting shackle (372), or the mooring cable (41); the speed sensor (62) and the angle sensor (63) are disposed at least once in one of the drive shaft (31), the sprocket (32), or the generator shaft (353); the counterweight displacement sensor (64) is used to detect the vertical displacement of the counterweight (52) relative to its initial position; The controller (65) determines the relative displacement of the chain (36) relative to the initial position based on the pitch circle radius of the sprocket (32) and the rotation angle collected by the rotation angle sensor (63), and determines the remaining adjustment stroke based on the difference between the maximum allowable displacement of the chain (36) and the absolute value of the current relative displacement.

8. A method for regulating mooring force and recovering energy of a floating photovoltaic platform at sea using the system described in any one of claims 1 to 7, characterized in that, Includes the following steps: The mooring side tension, transmission speed, sprocket angle and counterweight displacement of the mooring position equipped with the aforementioned direction adaptive guidance device (2) and mooring force regulation and energy recovery device (3) are collected, and the platform displacement and motion direction of the floating photovoltaic platform (1) are obtained. The relative displacement of the chain (36) relative to the initial position is determined based on the pitch circle radius of the sprocket (32) and the sprocket rotation angle, and the remaining adjustment stroke is determined based on the difference between the maximum allowable displacement of the chain (36) and the absolute value of the current relative displacement. The chain release-recovery cycle is identified based on the direction of movement and relative displacement change of the chain (36). One or more complete release-recovery cycles are combined into an evaluation period, and the displacement characteristics of the chain relative displacement, counterweight displacement or platform displacement in the previous evaluation period are extracted. When the displacement characteristic is lower than the lower limit of the preset target range, the target electromagnetic damping for the next evaluation period is reduced; when the displacement characteristic is higher than the upper limit of the preset target range, the target electromagnetic damping for the next evaluation period is increased; when the displacement characteristic is within the preset target range, the current target electromagnetic damping is maintained. During the next evaluation period, the generator (351) is controlled to apply electromagnetic damping opposite to the direction of motion to the release and retraction of the chain (36) according to the target electromagnetic damping, and the electrical energy generated by the generator (351) driven by the reciprocating motion of the chain (36) is rectified by the rectifier module (67) and then sent to the energy storage unit (68). When the relative displacement of the chain, the displacement of the counterweight, the displacement of the platform, the transmission speed, or the tension on the mooring side approaches the corresponding safety limit or an abnormality occurs, protective damping adjustment is performed.

9. The method for mooring force regulation and energy recovery of a floating photovoltaic platform at sea according to claim 8, characterized in that, The evaluation period includes one or more complete chain release-recovery cycles; the displacement characteristics include at least one of the following: chain relative displacement, counterweight displacement, or platform displacement amplitude, root mean square value, maximum absolute value, center offset, and the percentage of time exceeding a preset displacement value. During the same evaluation period, the target electromagnetic damping remains unchanged or within the preset allowable fluctuation range. The generator (351) generates electromagnetic torque opposite to the direction of chain movement during the release and retraction of the chain (36), and recovers mechanical energy in the bidirectional reciprocating motion.

10. The method for mooring force regulation and energy recovery of a floating photovoltaic platform at sea according to claim 8, characterized in that, When the relative displacement of the chain, the displacement of the counterweight, or the displacement of the platform reaches the corresponding safe displacement threshold, or when the transmission speed reaches the preset speed threshold, the electromagnetic damping of the generator (351) is increased to limit the movement; when the mooring side tension reaches the preset tension threshold, the remaining adjustment stroke is greater than the preset safe stroke, and the relative displacement of the chain, the displacement of the counterweight, and the displacement of the platform have not reached the corresponding safe displacement threshold, the current electromagnetic damping of the generator (351) is reduced or the current electromagnetic damping is limited to continue to increase in order to release the compensation displacement.

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