Variable cross-section friction-electromagnetic composite power generation raft type buoy and method

Abstract

This invention discloses a variable cross-sectional area friction-electromagnetic composite power generation raft buoy and method, solving the problems of low power generation efficiency caused by the non-adjustable natural frequency and mismatch between the optimal operating frequencies of TENG and EMG in existing wave energy buoys. This invention dynamically adjusts the raft width through a symmetrically arranged variable cross-sectional area mechanism, enabling the natural pitch frequency to track common ocean wave frequencies of 0.5Hz-2Hz in real time, achieving broadband resonance energy capture. It innovatively designs a dual-path transmission module, simultaneously decomposing the same wave pitch motion into a low-frequency extension motion matching the TENG and a high-frequency linear motion matching the EMG, allowing both to operate within their peak efficiency range. Hydraulic transmission is used to transfer mechanical energy, and multiple buoys can be quickly hinged together to form an expandable power generation array. This invention improves wave energy capture efficiency by more than 3 times across all sea states and increases total power generation by more than 60%, making it suitable for self-powering distributed equipment such as ocean buoys, observation stations, and underwater sensors.

Description

Technical Field

[0001] This invention relates to the field of marine renewable energy utilization technology, specifically to the field of wave energy conversion device technology, and particularly to a variable cross-sectional area friction-electromagnetic composite power generation raft buoy and method. Background Technology

[0002] With the acceleration of the global energy transition and the advancement of net-zero emissions goals, marine renewable energy, as a vast, widely distributed, clean, and pollution-free green energy source, is becoming a key focus of national energy strategies. Among these, wave energy boasts the highest energy density and widest distribution of marine energy, with a theoretical reserve exceeding 3 TW and a exploitable capacity of approximately 2 TW, far surpassing other marine energy sources such as tidal and ocean current energy, demonstrating extremely high development value and application prospects. In today's rapidly developing marine economy, the demand for long-term, stable, and low-cost power supply for a large number of distributed marine devices, such as marine buoys, underwater sensors, marine observation stations, and underwater robots, is increasingly urgent. However, traditional battery-powered systems suffer from short operating range, high replacement costs, and difficult maintenance, severely hindering the large-scale deployment of marine observation networks. Therefore, developing efficient and reliable wave-energy self-powered buoy technology to achieve energy self-sufficiency for marine equipment has become a critical issue urgently needing to be addressed in the field of marine engineering.

[0003] Among numerous wave energy generation devices, raft-type power generation devices have been widely studied and applied due to their unique structural advantages. This device uses multiple articulated buoys that rise and fall with the waves, efficiently absorbing the pitching and rolling energy of the waves, and is insensitive to changes in wave direction, eliminating the need for frequent orientation adjustments. Its overall stress is evenly distributed, providing strong resistance to wind and waves, and ensuring safe and reliable operation. Furthermore, its modular design facilitates manufacturing, installation, and maintenance, and the power generation scale can be easily expanded by increasing the number of rafts, demonstrating excellent energy capture efficiency and good potential for large-scale application.

[0004] However, existing raft-type wave energy buoys generally suffer from a fatal technical flaw: their power generation efficiency is highly dependent on the resonance effect, meaning that maximum energy capture can only be achieved when the natural frequency of the buoy precisely matches the frequency of the incident waves. The fixed geometry of traditional buoys results in a single, unadjustable natural frequency, enabling resonant power generation only under designed sea states. However, actual ocean wave frequencies exhibit strong randomness and time-varying characteristics, fluctuating within a wide range of 0.5Hz-2Hz due to seasonal changes, storm passage, and tidal variations. Once the wave frequency deviates from the design value, the buoy's resonance state is disrupted, its motion response weakens drastically, and power generation efficiency drops by more than 50%, or even ceases to generate electricity normally. This problem severely limits the stable operation of wave energy buoys in all sea states, becoming a major technical bottleneck restricting their large-scale application.

[0005] To address the issue of the unadjustable natural frequency of wave energy buoys, scholars both domestically and internationally have conducted extensive research, proposing various wave energy buoy schemes with variable structures. For example, Chinese patent CN120039355B proposes a wave energy buoy with a variable length and angle damping plate and its control method, which adjusts the natural frequency by changing the added mass and damping coefficient of the buoy through adjusting the length and angle of the damping plate; Chinese patent CN117550017B proposes a Spar-shaped wave energy buoy device and method with a variable tailpipe length, which adjusts the natural frequency by changing the draft and moment of inertia of the buoy through telescoping the tailpipe; and Chinese patent CN120039354B proposes a wave energy buoy with a variable float diameter and its control method, which adjusts the restoring moment coefficient of the buoy by changing the cross-sectional area of ​​the float, thereby adjusting its pitch natural frequency.

[0006] While the aforementioned solutions, through ingenious mechanical design, break through the physical limitations of traditional fixed buoys and broaden their operating frequency range to some extent, fundamental technical shortcomings remain. These solutions overemphasize the resonance effect between the buoy and waves, focusing entirely on improving wave energy capture efficiency while completely neglecting the core challenge of energy conversion. In fact, if the generator's rated power and energy conversion efficiency cannot meet system requirements, even if the buoy achieves perfect wave energy absorption, the captured mechanical energy cannot be efficiently converted into electrical energy, and the overall output capacity will still struggle to achieve a qualitative leap. A more effective technical approach would be to improve the generator's performance and then combine this with variable structure technology to overcome the frequency limitations of traditional buoys, simultaneously addressing both energy capture and energy conversion to achieve an order-of-magnitude increase in power generation.

[0007] The emerging hybrid power generation technology combining triboelectric nanogenerators (TENGs) and electromagnetic generators (EMGs) offers a novel approach to addressing the aforementioned challenges. TENGs, operating on the principles of triboelectric charging and electrostatic induction, offer advantages such as high output voltage, excellent low-frequency power generation performance, simple structure, and low cost. EMGs, based on the principle of electromagnetic induction, boast advantages including high output current, high energy conversion efficiency, and mature technology. The TENG-EMG hybrid generator, combining the complementary characteristics of both power generation methods, significantly improves energy conversion efficiency across a wide frequency range and has become a research hotspot in the field of wave energy power generation.

[0008] However, most existing TENG-EMG hybrid power generation buoys simply mechanically superimpose the two power generation methods, failing to address the core issue of the mismatch between their optimal operating frequencies. The optimal operating frequency for TENG is typically 2-4Hz, while for EMG it is usually 5-10Hz, a significant frequency difference. Even with variable structure technology to achieve resonance between the buoy and waves, only one generator can operate within its optimal frequency range, while the other inevitably operates inefficiently, failing to fully leverage the synergistic advantages of hybrid power generation. This problem results in the actual power output of existing hybrid power generation buoys being far lower than the theoretical value, severely limiting their performance improvement. Summary of the Invention

[0009] The purpose of this invention is to provide a variable cross-sectional area friction-electromagnetic hybrid power generation raft buoy and method. By deeply integrating variable cross-sectional area broadband resonant energy capture with dual-frequency decoupling hybrid power generation technology, it overcomes the industry pain points of poor sea state adaptability of traditional buoys and the inability of TENG-EMG hybrid power generation to work optimally at the same time. The wave energy conversion efficiency is improved by more than 3 times under all sea states.

[0010] The technical solution adopted in this invention is as follows: A variable cross-sectional area friction-electromagnetic composite power generation raft buoy includes a raft shell and further includes: a variable cross-sectional area mechanism, installed on the raft shell, for dynamically adjusting the width of the raft to change the overall cross-sectional area, so that the raft's natural pitching frequency tracks the real-time wave frequency to achieve resonance; a hydraulic transmission module, hinged to the front base of the raft shell, for converting the raft's pitching motion with the waves into the reciprocating flow of hydraulic medium; and a TENG-EMG power generation module, housed in the internal cavity of the raft shell and fluidly connected to the hydraulic transmission module via a needle tube; the TENG-EMG power generation module includes a hydraulic pressure converter, a dual-path transmission module, and a TENG-EMG generator. The system includes an NG power generation unit and an EMG power generation unit; the hydraulic pressure converter is used to convert the reciprocating flow of hydraulic medium into linear reciprocating motion; the dual-path transmission module is connected to the hydraulic pressure converter and is used to simultaneously decompose the linear reciprocating motion of the same input into a first frequency of telescopic motion and a second frequency of rotational-linear reciprocating motion, wherein the first frequency matches the optimal operating frequency of the TENG power generation unit and the second frequency matches the optimal operating frequency of the EMG power generation unit; the TENG power generation unit is driven to generate electricity by the first frequency of telescopic motion, and the EMG power generation unit is driven to generate electricity by the second frequency of rotational-linear reciprocating motion.

[0011] Preferably, the variable cross-sectional area mechanism includes a fixed cavity, a moving cavity, four linear motors, and a waterproof sealing assembly; the fixed cavity is fixed to the side of the raft shell, and has multiple protruding guide rail blocks on its outer side, with the moving cavity slidingly engaged with the guide rail blocks; the bases of the four linear motors are all fixed inside the fixed cavity, and their output ends are respectively sealed to the moving cavity through O-ring waterproof rubber rings and screws, for synchronously driving the moving cavity to reciprocate along the guide rail blocks; at least three square waterproof rubber rings are embedded between the mating surfaces of the moving cavity and the fixed cavity.

[0012] Preferably, the hydraulic transmission module includes a syringe holder, a syringe, a piston, a push rod, a push rod rear end holder, and a push rod rear end limiting seat; the syringe is fixedly installed inside the syringe holder, the piston is fixed to the front end of the push rod and slides in a sealing fit with the inner wall of the syringe; the rear end of the push rod is slidably accommodated in the push rod rear end holder, and the push rod rear end limiting seat is fixed to the rear end of the push rod rear end holder to limit the maximum backward stroke of the push rod; both the syringe holder and the push rod rear end limiting seat have mounting holes at their tail ends, and are hinged to the base at the front end of the raft shell to form a rotating pair by means of plug screws and nuts; the syringe outlet is connected to the hydraulic pressure converter of the TENG-EMG power generation module through the needle tube.

[0013] Preferably, the hydraulic pressure converter includes a driven push rod, a double-ear drive seat, and two symmetrically arranged rack bases; one end of the driven push rod is fixedly connected to the syringe piston communicating with the needle tube, and the other end is fixedly connected to the central protrusion of the double-ear drive seat; the two rack bases are respectively fixed below the two ends of the double-ear drive seat and slidably mounted on the reciprocating moving seat; a rack is fixed on the upper surface of each rack base, and a telescopic frame drive component is fixed on the side.

[0014] Preferably, the dual-path transmission module is symmetrically arranged in two sets corresponding to the two rack bases. Each set includes a fixed plate, a gear, a short transmission shaft, a rotating disk, a telescopic frame locking component, and a telescopic frame mounting base. The reciprocating moving seat, the C-shaped bearing seat, the telescopic frame mounting base, and the bearing fixing block are all fixed to the fixed plate. The two ends of the short transmission shaft are respectively supported by bearings on the C-shaped bearing seat and the bearing fixing block. The gear is tightly fitted in the middle of the short transmission shaft and meshes with the rack for transmission. The rotating disk is tightly fitted in the beginning of the short transmission shaft. The telescopic frame locking component is installed at the end of the C-shaped bearing seat and hinged to the telescopic frame mounting base.

[0015] Preferably, the TENG power generation unit includes two sets of symmetrically arranged scissor-type telescopic frames, a TENG mover slider, and four friction material fixing plates; one end of the rear end of each scissor-type telescopic frame is hinged to the corresponding telescopic frame drive component, and the other end of the rear end is hinged to the corresponding telescopic frame locking component; the front ends of both scissor-type telescopic frames are hinged to the TENG mover slider; the TENG mover slider is slidably mounted on two parallel guide optical axes through four linear bearings, and a FEP film is uniformly fixed at every 90° circumferential angle; the four friction material fixing plates are uniformly arranged at every 90° circumferential angle and fixed to the support frame, and each friction material fixing plate has an electrode support plate, an electrode, and a rabbit fur layer sequentially arranged on its surface, with the FEP film and the rabbit fur layer being arranged opposite each other and capable of generating relative sliding friction.

[0016] Preferably, the EMG power generation unit includes two symmetrically arranged reciprocating slides, two transmission rods, forty permanent magnets, and six electromagnetic coils. Each reciprocating slide includes two optical shafts and a sliding block, which is slidably mounted on the two optical shafts via two linear guide sleeves. The end face of the rotating disk is provided with an eccentric cylinder, which slides in cooperation with the guide groove of the sliding block to convert the rotational motion of the rotating disk into the linear reciprocating motion of the sliding block. One end of each transmission rod is fixedly connected to the corresponding sliding block via a transmission stud. The twenty permanent magnets are sequentially fixed to each transmission rod along the axial direction. The six electromagnetic coils are divided into two groups of three, each group having three coils, all coaxially sleeved on the outside of the corresponding transmission rod and fixed to the support frame via a copper column base, a copper column, an electromagnetic coil connecting plate, and an electromagnetic coil seat. When the permanent magnets reciprocate with the transmission rods, they cut the magnetic field lines of the electromagnetic coils to generate electrical energy.

[0017] Preferably, the support frame of the TENG-EMG power generation module includes a front mounting plate, a middle partition plate, a rear fixing plate, and the guide optical axis; the front mounting plate, the middle partition plate, and the rear fixing plate are arranged in parallel, and the two ends of the guide optical axis are respectively fixed to the front mounting plate and the rear fixing plate.

[0018] Preferably, a hinge connector is also fixed to the front end of the raft shell, and multiple raft buoys are sequentially hinged through the hinge connector to form an expandable raft power generation array.

[0019] Energy Conversion and Adaptive Control Method for Variable Cross-sectional Area Friction-Electromagnetic Composite Power Generation Raft Buoy Includes the following steps: S1. The intelligent control system automatically adjusts the sampling frequency of the wave sensor according to the current wave and sea conditions, and periodically collects real-time wave frequency data at preset time intervals. S2. Based on the collected real-time wave frequency data, an intelligent prediction algorithm is used to predict the short-term wave frequency; S3. If the predicted wave frequency exceeds the preset safe operating frequency range, the system immediately enters the protection mode: the linear motor controlling the variable cross-sectional area mechanism drives the moving cavity to retract the raft to the minimum width and cuts off the power generation output circuit to stop power generation. S4. If the predicted wave frequency is within the preset safe operating frequency range, the corresponding optimal raft width is matched from the pre-built frequency-optimal width matching database. The database is based on the raft pitching motion equation and resonance tuning principle to pre-calibrate the correspondence between wave frequency and raft width under different sea conditions. S5. Detect the actual width of the current raft. If it is inconsistent with the optimal width, control the linear motor of the variable cross-sectional area mechanism to synchronously drive the moving cavity to move and adjust the raft width to the optimal width. S6. Repeat steps S2 to S5 at preset time intervals to achieve dynamic tracking and adaptive control of the raft's natural pitching frequency on the real-time wave frequency. S7. The raft generates a pitching resonance motion with the waves, and the mechanical energy is transmitted to the hydraulic pressure converter of the TENG-EMG power generation module through the hydraulic transmission module. The first frequency of the telescopic motion is output through the dual transmission module to drive the TENG power generation unit to generate electricity, and the second frequency of the rotary-linear reciprocating motion is output to drive the EMG power generation unit to generate electricity, thus completing the composite conversion of wave energy to electrical energy.

[0020] The beneficial effects of this invention are as follows: This invention addresses three core industry pain points commonly found in existing wave energy buoys: unadjustable inherent frequency, low energy conversion efficiency, and mismatch between the optimal operating frequencies of triboelectric nanogenerators (TENGs) and electromagnetic generators (EMGs). It innovatively integrates variable cross-sectional area resonant tuning technology with dual-frequency decoupling composite power generation technology, systematically innovating the technology in three core aspects: wave energy capture, mechanical energy transfer, and electrical energy conversion. This comprehensively improves the device's power generation performance, sea condition adaptability, and operational reliability, achieving significant technical effects and application value.

[0021] In the wave energy capture stage, this invention completely solves the industry problem of poor sea state adaptability of traditional fixed cross-sectional area buoys. Traditional buoys, due to their single natural frequency, can only achieve resonant power generation under the designed sea state. Once the wave frequency deviates due to seasonal changes, storms, or other factors, the power generation efficiency drops sharply by more than 50%, making it difficult to operate stably in all sea states. This invention establishes a quantitative correspondence between wave frequency and optimal raft width based on the raft pitching motion equation. Through two symmetrically arranged variable cross-sectional area mechanisms, the moving cavity is smoothly extended and retracted along the T-shaped guide rail by four synchronously controlled waterproof linear motors. The overall width of the raft can be precisely adjusted within the range of 1000mm to 1600mm, enabling the device's pitching natural frequency to track common ocean wave frequencies from 0.5Hz to 2Hz in real time, always maintaining a resonant state. The wave energy capture efficiency is improved by more than 3 times in all sea states. Meanwhile, the variable cross-sectional area mechanism adopts a sealing structure combining O-ring rubber rings and multi-layer square waterproof rubber rings, achieving IP68 protection. This effectively solves the problems of poor sealing reliability and susceptibility to seawater corrosion in existing variable structure buoys, ensuring that the core moving parts can work stably for a long time in harsh marine environments.

[0022] The core technological breakthrough of this invention lies in its pioneering dual-frequency decoupling transmission system, which completely overcomes the common problem in existing TENG-EMG hybrid power generation technologies: "the inherent difference in the optimal operating frequencies of the two generators prevents them from simultaneously achieving their best performance." Existing technologies simply superimpose the two power generation methods; even if the floating body achieves resonance with the waves, only one generator can operate at its optimal state, while the other operates in an inefficient range, greatly limiting the advantages of hybrid power generation. This invention innovatively designs a dual-path transmission architecture with a gear-eccentric wheel and a scissor-type telescopic frame running in parallel. This simultaneously decomposes the same input wave pitching motion into two independent transmission paths: one path directly drives the scissor-type telescopic frame through the telescopic frame drive component to generate low-frequency telescopic motion at the same input frequency; the other path uses rack and pinion gear meshing to achieve frequency amplification, and then the rotating disk eccentric mechanism converts the rotational motion into high-frequency linear reciprocating motion. By pre-calibrating an optimal transmission ratio of 2.5:1, the low-frequency motion is precisely matched to the optimal operating frequency of the TENG power generation unit (2-4Hz), and the high-frequency motion is precisely matched to the optimal operating frequency of the EMG power generation unit (5-10Hz). When the raft resonates with the waves, the TENG and EMG can operate simultaneously within their respective peak efficiency ranges, fully leveraging the synergistic advantages of the TENG's high-voltage output and the EMG's high-current output. Compared to simple superimposed hybrid power generation devices, the total power generation is increased by more than 60%, and the energy conversion density reaches 120W / m³. 2 .

[0023] Building upon this foundation, the triboelectric-electromagnetic hybrid power generation architecture constructed in this invention further achieves high-efficiency energy conversion across the entire frequency band, integrating the complementary characteristics of the two power generation methods. The TENG power generation unit employs four circumferentially evenly arranged FEP-rabbit hair friction pairs, driven by a scissor-type telescopic frame to achieve large-stroke reciprocating friction, exhibiting extremely high power generation efficiency under low-frequency waves (<3Hz), effectively capturing the most abundant low-frequency wave energy in the ocean. The EMG power generation unit utilizes a moving magnet structure with multiple permanent magnets and multiple coils, achieving high-frequency reciprocating motion through an eccentric wheel mechanism, significantly improving output power under mid-to-high frequency waves (>3Hz), perfectly compensating for the performance degradation of TENG at high frequencies. The output characteristics of the two power generation methods are naturally complementary, and after simple rectification and voltage regulation circuitry, they can directly charge lithium batteries without the need for a complex power management system, greatly reducing system complexity and manufacturing costs.

[0024] This invention retains and optimizes the modular design advantages of raft-type power generation devices. A single buoy integrates all functions of energy capture, transmission, power generation, and control, and can be used independently to power low-power devices such as small marine sensors and underwater monitoring nodes. Multiple buoys can be quickly hinged together via standard hinge connectors at the front end to form a raft-type power generation array of arbitrary length. The power output increases linearly with the number of buoys, flexibly meeting the power supply needs of different power levels for marine observation stations, underwater robots, maritime navigation marks, and marine ranch monitoring systems. Simultaneously, the array structure distributes stress evenly, providing strong overall resistance to wind and waves. It can operate normally in sea state 6. When encountering extreme sea states of 8 or higher, the device can automatically retract the raft to its minimum width and enter a protection mode through an intelligent control system, effectively preventing damage to the device.

[0025] To achieve long-term unattended operation, this invention is equipped with a complete intelligent adaptive control system. It employs an LSTM neural network algorithm to predict short-term wave frequencies with an accuracy exceeding 95%, enabling advance adjustment of the raft width to avoid power generation efficiency losses due to sudden wave frequency changes. The system can also automatically adjust the sampling frequency of the wave sensor based on real-time sea conditions. It reduces the sampling frequency to save energy during calm seas and increases it to ensure response speed during rough seas, achieving an optimal balance between energy consumption and performance. Furthermore, the system incorporates an over-frequency safety protection mechanism. When the predicted wave frequency exceeds the preset safe operating range, it automatically retracts the raft to its minimum width and cuts off the power generation output circuit, maximizing protection of the device from the impact of extreme waves.

[0026] In summary, this invention fundamentally breaks through the technical bottlenecks of existing wave energy power generation buoys, achieving an organic unity of wide-band energy capture, high-efficiency conversion, and reliable operation. It provides a highly reliable, low-cost, and maintenance-free self-powered solution for marine distributed equipment such as ocean buoys, ocean observation networks, and underwater sensor networks. This is of great significance and has broad market prospects for promoting the large-scale application of blue energy and contributing to the green development of the marine economy. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the external structure of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0028] Figure 2 This invention relates to the external structure of the raft shell of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy.

[0029] Figure 3 This invention relates to the external structure of the hydraulic transmission module of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy.

[0030] Figure 4 This invention relates to the internal structure of a hydraulic transmission module for a variable cross-sectional area friction-electromagnetic composite power generation raft buoy.

[0031] Figure 5 This is a schematic diagram of the needle tube of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0032] Figure 6 This is an external schematic diagram of the TENG-EMG power generation module of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0033] Figure 7 This is a schematic diagram of the internal structure of the TENG-EMG power generation module of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0034] Figure 8 This is a schematic diagram of the hydraulic pressure converter structure of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0035] Figure 9 This is a schematic diagram of the dual-path transmission module structure of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0036] Figure 10 This is a schematic diagram of the scissor-type telescopic frame structure of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0037] Figure 11This is a schematic diagram of the TENG mover slider structure of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0038] Figure 12 This is a schematic diagram of the reverse side structure of the TENG mover slider of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0039] Figure 13 This is a schematic diagram of the friction material fixing plate of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0040] Figure 14 This is a schematic diagram of the frictional engagement between the TENG mover slider and the friction material fixing plate of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0041] Figure 15 This is a schematic diagram of the reciprocating slide structure of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0042] Figure 16 This is a schematic diagram of the electromagnetic power generation module mover of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0043] Figure 17 This is a schematic diagram of the stator of the electromagnetic power generation module of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0044] Figure 18 This is an external schematic diagram of the variable cross-sectional area mechanism of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0045] Figure 19 This is a schematic diagram of the fixed cavity of the variable cross-sectional area mechanism of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0046] Figure 20 This is a schematic diagram of the internal structure of the variable cross-sectional area mechanism of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0047] Figure 21 This is a flowchart of a variable cross-sectional area method for a variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to the present invention.

[0048] The components include: 1. Raft shell; 2. Variable cross-sectional area mechanism; 3. TENG-EMG power generation module; 4. Hydraulic transmission module; 5. Hinge connector; 6. Base; 7. Reciprocating slide; 8. Scissor-type telescopic frame; 21. Fixed cavity; 22. Moving cavity; 23. Linear motor; 24. O-ring waterproof rubber ring; 25. Square waterproof rubber ring; 31. Dual-path transmission module; 31a. C-type bearing seat; 31b. Fixing plate; 31c. Telescopic frame mounting base; 31d. Nut; 31e. Rotating disc; 31f. Short transmission shaft; 31g. Bearing fixing block; 31h. 31i. Gear; 31j. Telescopic frame locking component; 32. Bearing; 33. Front mounting plate; 33. Hydraulic pressure converter; 33a. Double-ear transmission seat; 33b. Rack base; 33c. Telescopic frame drive component; 33d. Rack; 33e. Reciprocating moving seat; 33f. Driven push rod; 34. Intermediate partition plate; 35. TENG mover slider; 35a. FEP film; 35b. Acrylic plate; 35c. FEP support plate; 35d. Linear bearing; 35e. Slider; 35f. U-shaped fixing plate; 35g. Sleeve; 35h. Screw; 36. Guide light. 37. Shaft, Rear end fixing plate, 38. Electromagnetic power generation module, 38a. Transmission stud, 38b. Transmission rod, 38c. Magnet, 38d. Positioning sleeve, 38e. Nylon limiting sleeve, 38f. Guide copper sleeve, 38g. Guide sleeve seat, 38h. Copper column base, 38i. Copper column, 38j. Electromagnetic coil connecting plate, 38k. Electromagnetic coil seat, 38l. Electromagnetic coil, 39. Friction material fixing plate, 39a. Electrode support plate, 39b. Electrode, 39c. Rabbit fur layer, 41. Syringe fixing seat, 42. Push rod, 43. Push rod rear end fixing seat, 44. 45. Push rod rear end limit seat, syringe, 46. piston, 47. M10 plug screw, 48. M10 nut, 48a. syringe front support plate, 48b. syringe rear support plate, 48c. syringe lower support plate, 49. needle tube, 71. rear plate optical axis seat, 72. slide block, 73. optical axis, 74. middle plate optical axis seat, 75. linear guide sleeve, 81. side bearing, 82. plug screw, 83. rotating frame, 91. base plate, 92. left side wall, 93. right side wall, 94. front end wall, 95. rear end wall, 96. top plate, 97. internal reinforcing rib plate. Detailed Implementation

[0049] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. This embodiment fully discloses all the technical features of the present invention. Those skilled in the art can completely reproduce the technical solution of the present invention and achieve its technical effects based on this embodiment without creative effort. It should be noted that this embodiment is only used to explain the present invention and not to limit the scope of protection of the present invention. Any equivalent substitutions or simple modifications made based on the technical solution of the present invention fall within the scope of protection of the present invention.

[0050] This invention discloses a variable cross-sectional area friction-electromagnetic composite power generation raft buoy, the overall structure of which is as follows: Figure 1 As shown, the system mainly consists of four parts: the raft shell 1, the variable cross-sectional area mechanism 2, the TENG-EMG power generation module 3, and the hydraulic transmission module 4. The raft shell 1 serves as the load-bearing base for the entire device, providing installation space and marine environmental protection for all internal components. The variable cross-sectional area mechanism 2 is symmetrically installed on the left and right sides of the raft shell 1, used to dynamically adjust the overall width of the raft according to the real-time wave frequency, changing the cross-sectional area of ​​the raft. This allows the raft's natural pitching frequency to track the changing wave frequency, maintaining resonance and maximizing wave energy capture efficiency. The hydraulic transmission module 4 is hinged to the front base 6 of the raft shell 1, used to convert the pitching motion of the raft caused by the waves into the reciprocating flow of hydraulic medium, achieving contactless and low-loss transfer of mechanical energy. The TENG-EMG power generation module 3 is housed in the internal cavity of the raft shell 1 and is fluidly connected to the hydraulic transmission module 4 through a needle tube 49. It is used to simultaneously convert the mechanical energy carried by the hydraulic medium into triboelectric energy and electromagnetic energy, achieving efficient composite conversion of wave energy. Furthermore, multiple raft buoys described in this invention can be sequentially hinged together via hinge connector 5 to form a raft power generation array that can be expanded in any size, further enhancing the overall power generation capacity and meeting the power supply needs of marine equipment of different power levels.

[0051] The structure of the raft shell 1 is as follows Figure 2 As shown, the raft hull is constructed by welding together a base plate 91, a left side wall 92, a right side wall 93, a front end wall 94, a rear end wall 95, a top plate 96, and internal reinforcing ribs 97, forming a sealed rectangular cavity structure. Specifically, the base plate 91 constitutes the base plate of the raft hull 1, the left side wall 92 and the right side wall 93 constitute the left and right side walls of the raft hull 1, respectively, the front end wall 94 constitutes the front end wall, the rear end wall 95 constitutes the rear end wall, the top plate 96 constitutes the top plate, and the internal reinforcing ribs 97 serve as internal reinforcing ribs to enhance the overall structural strength and torsional stiffness of the raft hull 1, thereby improving its resistance to wind and waves under extreme sea conditions.

[0052] All steel plates are made of 6mm thick 316L stainless steel, which has excellent resistance to seawater corrosion. The steel plates are connected by a continuous full welding process, with a weld height of not less than 5mm. After welding, all welds are ground and polished to remove weld slag and burrs. Then, three layers of epoxy zinc-rich anti-corrosion primer and two layers of polyurethane topcoat are sprayed to ensure that the raft hull 1 has good watertightness and corrosion resistance, enabling it to operate stably in the marine environment for a long time.

[0053] A closed internal cavity measuring 800mm × 600mm × 500mm is formed in the middle of the raft shell 1. The dimensions of this cavity are designed according to the external dimensions of the TENG-EMG power generation module 3 to ensure that the TENG-EMG power generation module 3 can be securely installed at the bottom of the cavity with bolts. The inner wall of the cavity is also coated with an anti-corrosion coating to prevent seawater from seeping in and corroding the internal metal components. A base 6 and a hinge connector 5 are bolted to the front wall 94 of the raft shell 1. The base 6 is made of cast steel, is L-shaped, and is fixed to the middle of the front wall 94 with four M12 bolts. Its surface has multiple M10 threaded holes for installing the hydraulic transmission module 4. The hinge connector 5 is made of high-strength stainless steel, and there are two of them. They are fixed on the left and right sides of the front wall 94 respectively. The structure is a standard pin-type connector, which includes a pin with a diameter of 20mm and a bushing. It can realize free rotation between two adjacent raft shells 1, with a rotation angle range of ±30°. This allows the entire raft power generation array to adapt to wave motions of different directions and wavelengths, ensuring that each buoy can rise and fall independently with the waves and efficiently absorb wave energy.

[0054] The structure of variable cross-sectional area mechanism 2 is as follows Figure 18 , Figure 19 and Figure 20 As shown, it mainly consists of a fixed cavity 21, a moving cavity 22, four linear motors 23, an O-ring waterproof rubber ring 24, and a square waterproof rubber ring 25. In this embodiment, two sets of variable cross-sectional area mechanisms 2 are provided, symmetrically installed on the left side wall 92 and the right side wall 93 of the raft shell 1, respectively. The two sets of variable cross-sectional area mechanisms 2 are synchronously controlled by the same controller to jointly adjust the overall width of the raft, with an adjustment range of 1000mm to 1600mm.

[0055] The fixed cavity 21 is welded from 3mm thick 316L stainless steel plate, forming a rectangular hollow structure with dimensions of 600mm × 500mm × 200mm. One side wall is fixed to the side wall of the raft shell 1 by eight M8 bolts. Four raised T-shaped guide blocks, evenly arranged vertically and 500mm in length, are provided on the outer side wall of the fixed cavity 21 to provide guidance and support for the moving cavity 22, ensuring smooth reciprocating movement in the horizontal direction without tilting or jamming. A 10mm diameter wire hole is provided on each of the front and rear end walls of the fixed cavity 21 for leading out the power and control wires of the linear motor 23. The wire holes are sealed with waterproof sealant to a depth of at least 10mm to prevent seawater from entering the fixed cavity 21.

[0056] The movable cavity 22 is also welded from a 3mm thick 316L stainless steel plate, and has an overall rectangular cavity structure with one open end, measuring 620mm × 520mm × 250mm. The open end faces the fixed cavity 21, and the internal dimensions of the movable cavity 22 are slightly larger than the external dimensions of the fixed cavity 21, allowing the movable cavity 22 to fit over the outside of the fixed cavity 21 and slide along the guide block. A T-shaped groove is formed on the inner wall of the movable cavity 22 to mate with the T-shaped guide block. The inner wall of the groove is coated with molybdenum disulfide grease to reduce the sliding friction between the movable cavity 22 and the fixed cavity 21, thereby reducing the drive power of the linear motor 23.

[0057] All four linear motors 23 are waterproof linear servo motors with an IP68 protection rating, a rated thrust of 50N, and a rated stroke of 300mm. The four linear motors 23 are arranged in a 2×2 rectangular array inside the fixed cavity 21. The base of each linear motor 23 is fixed to the inner wall of the fixed cavity 21 with four M6 bolts, and its output shaft faces the moving cavity 22 horizontally. The output shaft end of the linear motor 23 has a 50mm diameter flange, which is fixed to the inner wall of the moving cavity 22 with four M5 screws. An O-ring waterproof rubber ring 24 is placed between the flange and the moving cavity 22. The O-ring waterproof rubber ring 24 is made of nitrile rubber resistant to seawater corrosion, with a wire diameter of 3mm, effectively preventing seawater from entering the fixed cavity 21 through the connection hole of the output shaft. The four linear motors 23 are synchronously controlled by the same PLC controller to ensure that the extension and retraction speed and displacement of their output shafts are completely consistent, with a synchronization error of no more than 0.1mm. This allows the moving cavity 22 to move smoothly horizontally, avoiding jamming or deformation caused by uneven force.

[0058] To further improve the waterproof sealing performance of the variable cross-sectional area mechanism 2, three square waterproof rubber rings 25 are embedded between the mating surfaces of the moving cavity 22 and the fixed cavity 21. The three square waterproof rubber rings 25 are evenly arranged vertically on the inner wall of the moving cavity 22, located at the upper, middle, and lower parts of the moving cavity 22, with a spacing of 150mm. The square waterproof rubber rings 25 are also made of nitrile rubber, with a cross-section of 10mm × 10mm square, enabling them to form a tight surface contact with the outer wall of the fixed cavity 21, providing a better seal than traditional round rubber rings. When the moving cavity 22 slides along the fixed cavity 21, the square waterproof rubber rings 25 remain tightly fitted to the outer wall of the fixed cavity 21, effectively preventing seawater from entering the interior of the fixed cavity 21 and protecting the internal linear motor 23 and electrical wiring from seawater corrosion.

[0059] The working principle of the variable cross-sectional area mechanism 2 is based on the equation of motion of the raft pitching body and the principle of resonance tuning. Its core formula is as follows: ; in, It is the natural circular frequency of the pitch. It is the restoring torque coefficient. It is the total inertia. It is the width of the raft. It is the length of the raft. It is the height of the raft. It is the draft. It is the density of seawater. It is gravitational acceleration. It is the wave number. This is the additional mass coefficient. As can be seen from the above formula, in the raft length... ,high Draft With parameters fixed, the natural circular frequency of the raft's pitching motion. Only with the width of the raft Therefore, by driving the moving cavity 22 horizontally with the linear motor 23, the overall width of the raft is changed. This allows adjustment of the raft's natural pitch frequency. This allows it to track the real-time changing frequency of ocean waves. The resonance condition is satisfied. This maximizes the wave energy capture efficiency. In this embodiment, the optimal raft width corresponding to different wave frequencies was calibrated through preliminary pool model tests, and a frequency-optimal width matching database was constructed to provide a basis for subsequent adaptive control.

[0060] The structure of hydraulic transmission module 4 is as follows: Figure 3 and Figure 4 As shown, it mainly consists of a syringe holder 41, a syringe 45, a piston 46, a push rod 42, a push rod rear end holder 43, and a push rod rear end limit seat 44. The hydraulic transmission module 4 is hinged to the base 6 at the front end of the raft shell 1 and can rotate freely with the pitching motion of the raft, thereby converting the pitching motion of the raft into the reciprocating linear motion of the push rod 42.

[0061] The syringe holder 41 is made of 6061 aluminum alloy and has an L-shaped structure. A 50mm diameter syringe mounting hole is provided on its horizontal section, and the syringe 45 is fixedly installed in this hole via an interference fit. The syringe 45 is made of transparent polycarbonate, with an inner diameter of 40mm and a length of 200mm, exhibiting good strength and corrosion resistance. It is filled with No. 46 anti-wear hydraulic oil as the transmission medium. The piston 46 is made of nitrile rubber, and two annular sealing grooves are provided on its outer circumference. Each groove contains an O-ring seal. The piston 46 slides and seals against the inner wall of the syringe 45, dividing the inside of the syringe 45 into two independent oil chambers with a sealing pressure of not less than 1MPa.

[0062] The push rod 42 is machined from 304 stainless steel round bar with a diameter of 12mm. Its front end is fixedly connected to the piston 46 via an M10 thread and is coated with thread sealant to prevent oil leakage. The rear end is slidably housed within the push rod rear end fixing seat 43. The push rod rear end fixing seat 43 is machined from 6061 aluminum alloy and has an overall cylindrical structure with an inner diameter of 13mm and a length of 100mm. It has a guide hole inside, and the rear end of the push rod 42 slides in fit with this guide hole. The inner wall of the guide hole is coated with grease to reduce the friction when the push rod 42 slides. The push rod rear end limiting seat 44 is machined from 6061 aluminum alloy and is fixed to the rear end of the push rod rear end fixing seat 43 by four M4 bolts. It has an 8mm diameter through hole in its center to limit the maximum backward stroke of the push rod 42 and prevent the piston 46 from dislodging from the rear end of the syringe 45.

[0063] Both the syringe holder 41 and the push rod rear end limit seat 44 are provided with mounting ears at their tail ends, and mounting holes with a diameter of 10mm are opened on the mounting ears. The mounting ears of the syringe holder 41 are hinged to the upper part of the base 6 through M10 screws 47 and M10 nuts 48, and the mounting ears of the push rod rear end limit seat 44 are hinged to the lower part of the base 6 through another set of M10 screws 47 and M10 nuts 48. The vertical distance between the two hinge points is 150mm, so that both the syringe holder 41 and the push rod rear end limit seat 44 can rotate around their respective hinge axes, forming two independent rotating pairs. When the raft moves with the waves, the base 6 swings up and down with the raft. Due to the different hinge point positions of the syringe holder 41 and the push rod rear end limit seat 44 with the base 6, a relative displacement will occur between them, thereby pushing the push rod 42 to make reciprocating linear motion in the syringe 45, causing the hydraulic oil in the syringe 45 to flow back and forth.

[0064] The front outlet of the syringe 45 is connected to the hydraulic pressure converter 33 of the TENG-EMG power generation module 3 via the needle tube 49. The structure of the needle tube 49 is as follows: Figure 5 As shown, the hose is made of high-pressure resistant stainless steel braided tubing with an inner diameter of 6mm and a rated working pressure of 2MPa. Both ends are equipped with stainless steel quick connectors for rapid connection and sealing with the syringe 45 and the hydraulic pressure converter 33. The needle tube 49 is 1000mm long, with a certain margin to accommodate the rotation of the hydraulic transmission module 4. When the push rod 42 pushes the piston 46 forward, the hydraulic oil in the front chamber of the syringe 45 is forced into the needle tube 49 and flows to the hydraulic pressure converter 33. When the push rod 42 moves backward, the hydraulic oil in the hydraulic pressure converter 33 flows back to the front chamber of the syringe 45 through the needle tube 49, thus realizing the reciprocating flow of the hydraulic medium and transmitting the pitching mechanical energy of the raft to the TENG-EMG power generation module 3.

[0065] The TENG-EMG power generation module 3 is the core component of this invention, and its external structure is as follows: Figure 6 As shown, the internal structure is as follows Figure 7 As shown, the TENG-EMG power generation module 3 mainly consists of five parts: a support frame, a hydraulic pressure converter 33, a dual-path transmission module 31, a TENG power generation unit, and an EMG power generation unit. The support frame provides mounting support for all transmission and power generation components; the hydraulic pressure converter 33 converts the reciprocating flow of hydraulic media into linear reciprocating motion; the dual-path transmission module 31 is connected to the hydraulic pressure converter 33, enabling the same input linear reciprocating motion to be simultaneously decomposed into two independent transmission paths, outputting two different frequencies of motion to drive the TENG and EMG power generation units respectively. The TENG power generation unit generates electricity using the principles of triboelectric charging and electrostatic induction, characterized by high output voltage; the EMG power generation unit generates electricity using the principle of electromagnetic induction, characterized by high output current. Working together, they significantly improve energy conversion efficiency over a wide frequency range.

[0066] The supporting frame mainly consists of a front mounting plate 32, a middle partition plate 34, a rear fixing plate 37, and guide optical shafts 36. The front mounting plate 32, middle partition plate 34, and rear fixing plate 37 are all made of 10mm thick 6061 aluminum alloy sheet, each measuring 600mm × 500mm. They are arranged parallel to each other and at equal intervals of 200mm. Two guide optical shafts 36 are provided, made of 16mm diameter chrome-plated stainless steel round bars, possessing good wear resistance and straightness, with a straightness error not exceeding 0.05mm / m. The two guide optical shafts 36 are arranged in parallel, their ends fixed to corresponding mounting holes in the front mounting plate 32 and rear fixing plate 37 via interference fits. The middle partition plate 34, through its through holes, also interferes with the guide optical shafts 36, thus connecting the front mounting plate 32, middle partition plate 34, and rear fixing plate 37 into a single, stable supporting frame structure.

[0067] Above the TENG-EMG power generation module 3 is a syringe for connecting the needle tube 49. The structure of this syringe is exactly the same as that of the syringe barrel 45 and piston 46 in the hydraulic transmission module 4. The syringe is supported by a front support plate 48a, a rear support plate 48b, and a lower support plate 48c. The front support plate 48a and the rear support plate 48b are fixed to the upper part of the front mounting plate 32 by bolts, and the lower support plate 48c is fixed to the bottom of the front support plate 48a and the rear support plate 48b by bolts. The syringe barrel is fitted into the arc-shaped groove of the lower support plate 48c to ensure that the syringe remains stable during operation and does not shake or shift.

[0068] The structure of the hydraulic pressure converter 33 is as follows Figure 8 As shown, it mainly consists of a driven push rod 33f, a double-ear transmission seat 33a, two rack bases 33b, two reciprocating moving seats 33e, two racks 33d, and two telescopic frame drive components 33c. The driven push rod 33f is made of 304 stainless steel round steel with a diameter of 10mm. Its front end is fixedly connected to the piston of the syringe, and its rear end is fixedly connected to the central protrusion of the double-ear transmission seat 33a by four M4 bolts. The double-ear transmission seat 33a is made of 6061 aluminum alloy and has an overall Y-shaped structure. Its lower ends are fixedly connected to the two rack bases 33b by four M4 bolts. The two rack bases 33b are symmetrically arranged on the left and right sides of the driven push rod 33f and are slidably mounted on the two reciprocating moving seats 33e. The reciprocating moving seat 33e is made of 6061 aluminum alloy. Its bottom is fixed to the front mounting plate 32 by bolts. A linear guide groove with a width of 10mm is opened on its upper surface. The bottom of the rack base 33b is provided with a slider that cooperates with the guide groove, so that the rack base 33b can move smoothly up and down along the reciprocating moving seat 33e with a stroke of 100mm.

[0069] Each rack base 33b has a rack 33d bolted to its upper surface. The rack 33d is made of 45# carbon steel, with a module of 2 and 50 teeth. Its tooth surface is high-frequency quenched, achieving a hardness of HRC45-50, resulting in high hardness and wear resistance. Each rack base 33b has a telescopic frame drive component 33c bolted to its outer edge. The telescopic frame drive component 33c is made of 304 stainless steel and has an M3 external thread at its head for hinged connection with the scissor-type telescopic frame 8.

[0070] When the hydraulic oil in the syringe 49 pushes the piston of the syringe to reciprocate, the piston drives the driven push rod 33f to move up and down synchronously. The driven push rod 33f then drives the two rack bases 33b to move up and down synchronously along the reciprocating moving seat 33e via the double-ear transmission seat 33a. When the rack base 33b moves up and down, the rack 33d on it and the telescopic frame drive component 33c on the side also move up and down synchronously, thus converting the reciprocating flow of the hydraulic medium into the linear reciprocating motion of the rack 33d and the telescopic frame drive component 33c, providing power input for the subsequent dual-path transmission.

[0071] Two sets of dual-path transmission modules 31 are symmetrically arranged corresponding to the two rack bases 33b, located on the left and right sides of the driven push rod 33f, respectively. Taking the left-side dual-path transmission module 31 as an example, its structure is as follows: Figure 9 As shown, it mainly includes a fixed plate 31b, a C-type bearing seat 31a, a bearing 31j, a short transmission shaft 31f, a gear 31h, a bearing fixing block 31g, a rotating disc 31e, a telescopic frame locking component 31i, and a telescopic frame mounting base 31c.

[0072] The fixing plate 31b is made of 8mm thick 6061 aluminum alloy sheet and is vertically fixed to the front mounting plate 32 by four M6 bolts. The reciprocating moving seat 33e, C-type bearing seat 31a, telescopic frame mounting seat 31c, and bearing fixing block 31g are all fixed to the same side of the fixing plate 31b by bolts. The C-type bearing seat 31a is located on the upper part of the fixing plate 31b, with a 20mm diameter bearing mounting hole in its center. The bearing 31j is a 6204 type deep groove ball bearing, interference-fitted into this mounting hole. The bearing fixing block 31g is located on the lower part of the fixing plate 31b, coaxially arranged with the C-type bearing seat 31a, and also has a 20mm diameter bearing mounting hole in its center, similarly interference-fitted with a 6204 type deep groove ball bearing.

[0073] The short drive shaft 31f is machined from 45# carbon steel round steel with a diameter of 20mm. Its two ends are interference-fitted with bearings 31j in C-type bearing housing 31a and bearing fixing block 31g, respectively, thus achieving rotational support for the short drive shaft 31f. The gear 31h is machined from 45# carbon steel with a module of 2 and 20 teeth. Its tooth surface has undergone high-frequency quenching treatment. It is interference-fitted and installed in the middle of the short drive shaft 31f, and the gear 31h meshes with the rack 33d, with a transmission ratio of 2.5:1. The rotating disk 31e is machined from 6061 aluminum alloy with a diameter of 100mm and a thickness of 10mm. It is interference-fitted and installed at the beginning of the short drive shaft 31f. A raised eccentric cylinder with a diameter of 10mm and a height of 15mm is provided on the edge of its end face. The axis of the eccentric cylinder is parallel to the axis of the short drive shaft 31f and 30mm away from it.

[0074] The telescopic frame mounting base 31c is located below the C-type bearing housing 31a and is fixed to the fixing plate 31b by bolts. The telescopic frame locking component 31i is made of 304 stainless steel and has an M3 external thread at its head. The telescopic frame locking component 31i passes through the mounting hole at the end of the C-type bearing housing 31a, and then passes through the mounting hole at the lower end of the scissor telescopic frame 8 and the mounting hole of the telescopic frame mounting base 31c in sequence. Finally, it is locked with the nut 31d, thereby realizing the hinge connection between the lower end of the scissor telescopic frame 8 and the telescopic frame mounting base 31c.

[0075] The core innovation of the dual-path transmission module 31 lies in its ability to decompose the linear reciprocating motion of the same frequency input from the rack base 33b into two independent transmission paths, outputting two different frequencies of motion. Specifically, the first transmission path is: rack base 33b moves up and down - rack 33d moves up and down - gear 31h rotates - short transmission shaft 31f rotates - rotating disk 31e rotates - reciprocating slide 7 moves linearly back and forth - EMG power generation unit generates electricity. The second transmission path is: rack base 33b moves up and down - telescopic frame drive 33c moves up and down - scissor telescopic frame 8 telescopic motion - TENG mover slider 35 moves linearly back and forth - TENG power generation unit generates electricity.

[0076] Because the rack and pinion drive has a fixed transmission ratio of 2.5:1, and the eccentric mechanism of the rotating disk 31e can convert rotational motion into high-frequency linear reciprocating motion, the output frequency of the first transmission path is 2.5 times the input frequency, while the output frequency of the second transmission path is the same as the input frequency. During the design, by rationally selecting the transmission ratio of gear 31h and rack 33d, as well as the eccentricity of the rotating disk 31e, the output frequency of the first transmission path can be made to match the optimal operating frequency (5-10Hz) of the EMG power generation unit, while the output frequency of the second transmission path can match the optimal operating frequency (2-4Hz) of the TENG power generation unit. Thus, when the raft resonates with the waves, as long as the pitching frequency of the raft matches the wave frequency, both the TENG and EMG power generation units can operate within their respective optimal frequency ranges, achieving efficient composite conversion of wave energy and solving the problem in existing technologies where TENG and EMG cannot operate at their optimal frequencies simultaneously.

[0077] The TENG power generation unit mainly includes two sets of symmetrically arranged scissor-type telescopic frames 8, a TENG moving slider 35, and four friction material fixing plates 39.

[0078] The structure of the scissor telescopic frame 8 is as follows: Figure 10 As shown, it mainly consists of 8 rotating frames 83, 8 locking screws 82, 8 side bearings 81, and 8 nuts 31d. The rotating frame 83 is made of 2mm thick 6061 aluminum alloy sheet, is long and 150mm in length, and has 5mm diameter mounting holes at both ends. The ends of adjacent rotating frames 83 are overlapped and hinged together by locking screws 82 and side bearings 81, forming a scissor-like structure. The side bearings 81 are fitted onto the smooth part of the locking screws 82, effectively reducing friction during rotation and improving the flexibility of the scissor-like telescopic frame 8. The ends of the locking screws 82 are locked to the nuts 31d to prevent the rotating frame 83 from detaching from the locking screws 82.

[0079] Each scissor-type telescopic frame 8 has two mounting holes at its rear end. One mounting hole engages with the M3 thread at the head of the telescopic frame drive component 33c and is locked with a nut 31d, thus achieving a hinged connection between the rear end of the scissor-type telescopic frame 8 and the telescopic frame drive component 33c. The other mounting hole engages with the M3 thread at the head of the telescopic frame locking component 31i and is locked with a nut 31d, thus achieving a hinged connection between the rear end of the scissor-type telescopic frame 8 and the telescopic frame mounting base 31c. When the telescopic frame drive component 33c moves up and down with the rack and pinion base 33b, the distance between the two hinge points at the rear end of the scissor-type telescopic frame 8 changes, thereby causing the scissor-type telescopic frame 8 to perform a folding and unfolding telescopic movement, with a maximum telescopic stroke of 200mm.

[0080] The structure of TENG mover slider 35 is as follows: Figure 11 and Figure 12 As shown, it mainly consists of a slider 35e, four linear bearings 35d, four FEP films 35a, four acrylic plates 35b, four FEP support plates 35c, and a U-shaped fixing plate 35f. The slider 35e is made of 6061 aluminum alloy and has a rectangular structure with dimensions of 100mm × 100mm × 50mm. Each of its four sides has a 5mm deep mounting groove. The four linear bearings 35d are arranged in a 2×2 rectangular array and are interference-fitted into corresponding through holes on the slider 35e. Two guide shafts 36 pass through the upper and lower linear bearings 35d respectively, allowing the TENG mover slider 35 to slide smoothly back and forth along the guide shafts 36.

[0081] Four FEP support plates 35c are fixed to the mounting slots on the four sides of the slider 35e by bolts. An acrylic plate 35b and an FEP film 35a are sequentially fixed to the outer side of each FEP support plate 35c. The acrylic plate 35b is 2mm thick and serves as an insulating layer to isolate the FEP film 35a from the metal slider 35e, preventing charge leakage. The FEP film 35a is 0.1mm thick and serves as a triboelectric material, possessing good electronegativity and wear resistance. Its surface is treated with argon plasma for 5 minutes to increase the amount of charge generated by triboelectric charging. The four FEP films 35a are evenly arranged at 90° intervals along the circumference of the slider 35e.

[0082] The U-shaped fixing plate 35f is made of 6061 aluminum alloy and has an overall U-shaped structure. It is fixed to the back of the slider 35e by four M4 bolts. Two screws 35h are installed in the inner groove of the U-shaped fixing plate 35f. Each screw 35h is fitted with a sleeve 35g and a bearing 31j, which can roll up and down within the inner groove of the U-shaped fixing plate 35f. The front end of the scissor-type telescopic frame 8 has two mounting holes. One mounting hole is fitted onto the upper bearing 31j, and the other mounting hole is fitted onto the lower bearing 31j, thus achieving the hinge connection between the front end of the scissor-type telescopic frame 8 and the TENG mover slider 35. When the scissor-type telescopic frame 8 extends or retracts, its two hinge points at the front end roll up and down within the inner groove of the U-shaped fixing plate 35f, simultaneously driving the TENG mover slider 35 to slide horizontally back and forth along the guide optical axis 36.

[0083] The structure of the friction material fixing plate 39 is as follows: Figure 13 As shown, it mainly consists of an electrode support plate 39a, an electrode 39b, and a rabbit hair layer 39c. The electrode support plate 39a is made of 5mm thick epoxy resin sheet, possessing good insulation properties and mechanical strength. The electrode 39b is made of 0.05mm thick copper foil, attached to the inner surface of the electrode support plate 39a via screen printing. A 0.5mm diameter copper wire is led out from the electrode 39b for outputting triboelectric energy. The rabbit hair layer 39c is adhered to the surface of the electrode 39b using epoxy resin adhesive; the rabbit hair is 5mm long and has a density of 100 hairs / cm². 2 As a positive triboelectric material, it can generate a large amount of charge when it comes into contact with the FEP film 35a.

[0084] Four friction material fixing plates 39 are evenly arranged at 90° intervals along the circumference and are fixed to the four sides of the support frame by bolts, forming the outer shell of the TENG-EMG power generation module 3. The rabbit fur layer 39c on each friction material fixing plate 39 is positioned opposite to the corresponding FEP film 35a on the TENG mover slider 35, with a 0.5mm gap between them. When the TENG mover slider 35 slides back and forth along the guide optical axis 36, the FEP film 35a and the rabbit fur layer 39c generate continuous relative sliding friction. According to the principle of triboelectricity, the FEP film 35a will acquire a negative charge, and the rabbit fur layer 39c will acquire a positive charge. As the TENG mover slider 35 slides, an induced potential difference is generated between the two electrodes 39b, thereby forming a current in the external circuit and realizing triboelectric power generation. When the raft resonates with the waves, the reciprocating displacement of the telescopic frame drive 33c reaches its maximum, thereby enabling the scissor telescopic frame 8 to obtain the maximum telescopic stroke. The sliding speed and displacement of the TENG mover slider 35 also reach their maximum, and the friction frequency and friction area between the FEP film 35a and the rabbit fur layer 39c also reach their maximum, thus enabling the TENG power generation unit to output maximum power.

[0085] The EMG power generation unit mainly includes two sets of symmetrically arranged reciprocating slides 7, two transmission rods 38b, forty permanent magnets 38c, and six electromagnetic coils 38l.

[0086] The structure of the reciprocating slide 7 is as follows Figure 15 As shown, it mainly consists of two optical axes 73, a rear plate optical axis seat 71, a middle plate optical axis seat 74, two linear guide sleeves 75, and a sliding block 72. The rear plate optical axis seat 71 is fixed to the rear end fixing plate 37 with bolts, and the middle plate optical axis seat 74 is fixed to the middle partition plate 34 with bolts. Each of the rear plate optical axis seat 71 and the middle plate optical axis seat 74 has a 10mm diameter mounting hole at its upper and lower ends. The two optical axes 73 are made of 10mm diameter chrome-plated stainless steel round steel, arranged in parallel, and their ends are respectively fixed to the corresponding mounting holes of the rear plate optical axis seat 71 and the middle plate optical axis seat 74 by interference fit. The two linear guide sleeves 75 are respectively interference-fitted into the upper and lower through holes of the sliding block 72. The optical axes 73 pass through the linear guide sleeves 75, allowing the sliding block 72 to slide smoothly back and forth along the optical axes 73. The side of the slide block 72 has a vertical guide groove with a width of 10mm and a length of 80mm. The width of the guide groove matches the diameter of the eccentric cylinder on the rotating disk 31e. The eccentric cylinder is inserted into the guide groove and can slide up and down in the guide groove.

[0087] When the rotating disk 31e rotates with the short transmission shaft 31f, the eccentric cylinder makes a circular motion around the axis of the short transmission shaft 31f, while simultaneously sliding up and down within the guide groove of the sliding block 72. This converts the rotational motion of the rotating disk 31e into the horizontal reciprocating motion of the sliding block 72 along the optical axis 73. By rationally designing the eccentricity of the rotating disk 31e, the reciprocating stroke of the sliding block 72 can be adjusted; by rationally designing the transmission ratio between the gear 31h and the rack 33d, the reciprocating frequency of the sliding block 72 can be adjusted to perfectly match the optimal operating frequency of the EMG power generation unit.

[0088] The structure of the electromagnetic power generation module mover is as follows: Figure 16 As shown, one end of the transmission stud 38a is embedded in the internal hexagonal hole of the sliding block 72 and is fixedly connected to the sliding block 72 by interference fit. The other end is connected to one end of the transmission rod 38b by an M8 thread and is coated with thread-locking adhesive to prevent loosening. The transmission rod 38b is machined from 304 stainless steel round bar with a diameter of 8mm, and its other end is mounted in the guide copper sleeve 38f inside the guide sleeve seat 38g. The guide sleeve seat 38g is fixed to the intermediate partition plate 34 by bolts, and the guide copper sleeve 38f is installed in the center hole of the guide sleeve seat 38g by interference fit, which can provide guiding support for the transmission rod 38b and ensure that the transmission rod 38b always reciprocates along the axial direction without radial deviation.

[0089] Twenty permanent magnets 38c are sequentially fixed axially onto each transmission rod 38b. Adjacent permanent magnets 38c are separated by 5mm long positioning sleeves 38d, made of non-magnetic 6061 aluminum alloy, to ensure uniform spacing between the permanent magnets 38c. A nylon limiting sleeve 38e is fitted at each end of the transmission rod 38b to limit its maximum reciprocating stroke and prevent collisions between the permanent magnets 38c and the electromagnetic coil 38l. The permanent magnets 38c are made of N52 grade neodymium iron boron permanent magnet material, with a diameter of 6mm and a thickness of 5mm. They are axially magnetized, and adjacent permanent magnets 38c have opposite magnetic poles, generating a strong magnetic field and improving electromagnetic power generation efficiency.

[0090] The structure of the stator of the electromagnetic power generation module is as follows: Figure 17 As shown, starting from the middle partition 34, a copper column base 38h, eight copper columns 38i, two electromagnetic coil connecting plates 38j, three electromagnetic coil seats 38k, and three electromagnetic coils 38l are installed sequentially. The copper column base 38h is fixed to the middle partition 34 with bolts. The eight copper columns 38i are arranged in a 2×4 rectangular array, with one end fixedly connected to the copper column base 38h via an M3 thread. The two electromagnetic coil connecting plates 38j and the three electromagnetic coil seats 38k are arranged alternately, sequentially fitted onto the copper columns 38i, and locked in place with nuts. The three electromagnetic coils 38l are respectively fixed to the three electromagnetic coil seats 38k with bolts. All electromagnetic coils 38l are coaxially arranged, and their central axis coincides with the axis of the transmission rod 38b. The electromagnetic coils 38l are made of 0.2mm diameter enameled copper wire, with each coil having 1000 turns. Wires are led out from both ends for outputting electromagnetic energy.

[0091] When the transmission rod 38b reciprocates with the sliding block 72, the permanent magnet 38c on it also reciprocates synchronously, passing through the interior of the electromagnetic coil 38l, causing the magnetic flux passing through the electromagnetic coil 38l to change periodically. According to the principle of electromagnetic induction, an induced electromotive force is generated in the electromagnetic coil 38l, thereby forming a current in the external circuit and realizing electromagnetic power generation. When the raft resonates with the waves, the double-ear transmission seat 33a obtains its maximum displacement, which in turn drives the rack 33d to obtain its maximum speed, the gear 31h and the rotating disk 31e to reach their highest speed, the reciprocating frequency of the transmission rod 38b also reaches its highest, and the permanent magnet 38c cuts the magnetic field lines at its fastest speed, thus enabling the EMG power generation unit to output maximum power.

[0092] This invention also discloses an energy conversion and adaptive control method for the aforementioned variable cross-sectional area friction-electromagnetic composite power generation raft buoy, the flowchart of which is shown below. Figure 21 As shown, the specific steps include: S1. The intelligent control system automatically adjusts the sampling frequency of the wave sensor according to the current wave and sea conditions, and periodically collects real-time wave frequency data at preset time intervals. When the sea conditions are stable and the wave frequency changes slowly, the sampling frequency is set to 1Hz; when the sea conditions are severe and the wave frequency changes drastically, the sampling frequency is increased to 10Hz to ensure the real-time performance and accuracy of the data acquisition. The wave sensor is a triaxial accelerometer, installed at the center of the raft hull 1, which can detect the raft's pitch acceleration in real time. By performing a fast Fourier transform on the acceleration signal, the real-time wave frequency data can be obtained.

[0093] S2. Based on the collected real-time wave frequency data, a Long Short-Term Memory (LSTM) neural network algorithm is used to predict the wave frequency within the next 10 seconds. The LSTM neural network model is pre-trained with a large amount of historical wave data, and the prediction accuracy can reach over 95%.

[0094] S3. If the predicted wave frequency exceeds the preset safe operating frequency range (0.5Hz-2Hz), the system immediately enters the protection mode: the linear motor 23 of the control variable cross-sectional area mechanism 2 drives the moving cavity 22 to retract the raft to the minimum width of 1000mm, and cuts off the power generation output circuit to stop power generation, so as to reduce the wave-facing area of ​​the buoy, reduce the impact force of the waves on the buoy, and protect the safety of the device.

[0095] S4. If the predicted wave frequency is within the preset safe operating frequency range, the corresponding optimal raft width is matched from a pre-built frequency-optimal width matching database. This database is pre-calibrated based on the raft pitching motion equation and water tank model test data, and contains optimal raft width data corresponding to all wave frequencies in the range of 0.5Hz-2Hz.

[0096] S5. The actual width of the raft is detected by the displacement sensor installed on the linear motor 23. If it is inconsistent with the optimal width, the four linear motors 23 of the variable cross-sectional area mechanism 2 are controlled to drive the moving cavity 22 to move synchronously, so as to accurately adjust the width of the raft to the optimal value with an adjustment accuracy of ±1mm.

[0097] S6. Repeat steps S2 to S5 every 10 seconds to achieve dynamic tracking and adaptive control of the raft's natural pitching frequency to the real-time wave frequency, so that the raft always maintains a resonant state.

[0098] S7. The raft generates a pitching resonance motion with the waves. The mechanical energy is transmitted to the hydraulic pressure converter 33 of the TENG-EMG power generation module 3 via the hydraulic transmission module 4. The mechanical energy is then simultaneously output by the dual-path transmission module 31. The first frequency of telescopic motion drives the TENG power generation unit to generate electricity, and the second frequency of rotary-linear reciprocating motion drives the EMG power generation unit to generate electricity, completing the composite conversion of wave energy to electrical energy. The high-voltage electrical energy output by the TENG power generation unit and the high-current electrical energy output by the EMG power generation unit are processed by their respective rectifier and voltage regulator circuits and then output in parallel to the lithium battery energy storage device or marine observation equipment to achieve continuous power supply for marine distributed equipment.

[0099] Furthermore, this invention employs a modular design, allowing multiple buoys to be sequentially hinged together via hinge connectors 5 to form an arbitrarily scalable raft-type power generation array. The hinge connector 5 at the rear of the first buoy and the hinge connector 5 at the front of the second buoy are connected via a pin to achieve the hinge connection between the two buoys. Similarly, any number of buoys can be sequentially hinged together to form a long, narrow raft-type power generation array. The power output terminals of all buoys are connected in parallel via waterproof cables to collectively power the load. By increasing the number of buoys, the total output power of the power generation array can be linearly increased to meet the power supply needs of marine equipment of different power levels.

[0100] This invention achieves wideband resonant energy capture through a variable cross-sectional area mechanism, and enables TENG and EMG to operate simultaneously at the optimal frequency through a dual-path drive module. Combined with a triboelectric-electromagnetic hybrid power generation mode, it significantly improves the conversion efficiency of wave energy, providing a highly reliable and low-cost self-powered solution for marine distributed equipment such as ocean buoys, ocean observation stations, and underwater sensors, with broad application prospects.

[0101] The above description is only 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 protection scope of the present invention.

Claims

1. A variable cross-sectional area friction-electromagnetic composite power generation raft buoy, comprising a raft shell (1), characterized in that, Also includes: A variable cross-sectional area mechanism (2) is installed on the raft shell (1) to dynamically adjust the width of the raft to change the overall cross-sectional area, so that the raft's natural pitching frequency tracks the real-time wave frequency to achieve resonance; a hydraulic transmission module (4) is hinged to the front base (6) of the raft shell (1) to convert the raft's pitching motion with the waves into the reciprocating flow of hydraulic medium; a TENG-EMG power generation module (3) is housed in the internal cavity of the raft shell (1) and is fluidly connected to the hydraulic transmission module (4) through a needle tube (49); the TENG-EMG power generation module (3) includes a hydraulic pressure converter (33), a dual-path transmission module (31), and a TENG The generator unit and the EMG generator unit; the hydraulic pressure converter (33) is used to convert the reciprocating flow of the hydraulic medium into linear reciprocating motion; the dual-path transmission module (31) is connected to the hydraulic pressure converter (33) and is used to simultaneously decompose the linear reciprocating motion of the same input into a first frequency of telescopic motion and a second frequency of rotational-linear reciprocating motion, wherein the first frequency matches the optimal operating frequency of the TENG generator unit and the second frequency matches the optimal operating frequency of the EMG generator unit; the TENG generator unit is driven to generate electricity by the first frequency of telescopic motion and the EMG generator unit is driven to generate electricity by the second frequency of rotational-linear reciprocating motion.

2. The variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to claim 1, characterized in that, The variable cross-sectional area mechanism (2) includes a fixed cavity (21), a moving cavity (22), four linear motors (23), and a waterproof sealing assembly. The fixed cavity (21) is fixed to the side of the raft shell (1), and a plurality of protruding guide blocks are provided on its outer side. The moving cavity (22) slides with the guide blocks. The bases of the four linear motors (23) are all fixed inside the fixed cavity (21), and their output ends are respectively sealed to the moving cavity (22) through O-ring waterproof rubber rings (24) and screws, for synchronously driving the moving cavity (22) to reciprocate along the guide blocks. At least three square waterproof rubber rings (25) are embedded between the mating surfaces of the moving cavity (22) and the fixed cavity (21).

3. The variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to claim 1, characterized in that, The hydraulic transmission module (4) includes a syringe holder (41), a syringe (45), a piston (46), a push rod (42), a push rod rear end holder (43), and a push rod rear end limiting seat (44); the syringe (45) is fixedly installed inside the syringe holder (41), the piston (46) is fixed to the front end of the push rod (42) and slides and seals against the inner wall of the syringe (45); the rear end of the push rod (42) is slidably accommodated in the push rod rear end holder (43), and the push rod rear end limiting seat (44) is... 44) Fixed to the rear end of the push rod rear end fixing seat (43) to limit the maximum backward stroke of the push rod (42); the tail ends of the syringe fixing seat (41) and the push rod rear end limiting seat (44) are provided with mounting holes, and are hinged to the base (6) at the front end of the raft shell (1) through M10 plug screws (47) and M10 nuts (48) to form a rotating pair; the outlet of the syringe (45) is connected to the hydraulic pressure converter (33) of the TENG-EMG power generation module (3) through the needle tube (49).

4. The variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to claim 1, characterized in that, The hydraulic pressure converter (33) includes a driven push rod (33f), a double-ear drive seat (33a), and two symmetrically arranged rack bases (33b). One end of the driven push rod (33f) is fixedly connected to the syringe piston communicating with the needle tube (49), and the other end is fixedly connected to the central protrusion of the double-ear drive seat (33a). The two rack bases (33b) are respectively fixed below the two ends of the double-ear drive seat (33a) and slidably mounted on the reciprocating moving seat (33e). Each rack base (33b) has a rack (33d) fixed on its upper surface and a telescopic frame drive component (33c) fixed on its side.

5. The variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to claim 4, characterized in that, The dual-path transmission module (31) is symmetrically arranged in two sets corresponding to the two rack bases (33b). Each set includes a fixed plate (31b), a gear (31h), a short transmission shaft (31f), a rotating disc (31e), a telescopic frame locking component (31i), and a telescopic frame mounting base (31c). The reciprocating moving seat (33e), the C-type bearing seat (31a), the telescopic frame mounting base (31c), and the bearing fixing block (31g) are all fixed to the fixed plate (31b). The short transmission shaft (31... f) is supported at both ends by bearings (31j) on the C-type bearing seat (31a) and the bearing fixing block (31g), respectively. The gear (31h) is tightly fitted to the middle of the short transmission shaft (31f) and meshes with the rack (33d) for transmission. The rotating disk (31e) is tightly fitted to the head end of the short transmission shaft (31f). The telescopic frame locking member (31i) is installed at the end of the C-type bearing seat (31a) and is hinged to the telescopic frame mounting base (31c).

6. The variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to claim 5, characterized in that, The TENG power generation unit includes two sets of symmetrically arranged scissor-type telescopic frames (8), TENG moving sliders (35), and four friction material fixing plates (39); one end of the rear end of each scissor-type telescopic frame (8) is hinged to the telescopic frame drive member (33c) on the corresponding side, and the other end of the rear end is hinged to the telescopic frame locking member (31i) on the corresponding side; the front ends of both scissor-type telescopic frames (8) are hinged to the TENG moving sliders (35); the TENG moving sliders (35) are connected by four linear bearings ( 35d) Slidingly mounted on two parallel guide optical axes (36), with a FEP film (35a) uniformly fixed at every 90° circumference; four friction material fixing plates (39) are uniformly arranged at every 90° circumference and fixed to the support frame. Each friction material fixing plate (39) has an electrode support plate (39a), an electrode (39b), and a rabbit fur layer (39c) arranged sequentially on its surface. The FEP film (35a) and the rabbit fur layer (39c) are arranged opposite to each other and can generate relative sliding friction.

7. The variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to claim 5, characterized in that, The EMG power generation unit includes two sets of symmetrically arranged reciprocating slides (7), two transmission rods (38b), forty permanent magnets (38c), and six electromagnetic coils (38l); each reciprocating slide (7) includes two optical shafts (73) and a slide block (72), the slide block (72) being slidably mounted on the two optical shafts (73) via two linear guide sleeves (75); the end face of the rotating disk (31e) is provided with an eccentric cylinder, the eccentric cylinder being slidably engaged with the guide groove of the slide block (72) to convert the rotational motion of the rotating disk (31e) into the linear reciprocating motion of the slide block (72); each One end of the transmission rod (38b) is fixedly connected to the corresponding sliding block (72) via a transmission stud (38a). Twenty permanent magnets (38c) are sequentially fixed to each transmission rod (38b) along the axial direction. The six electromagnetic coils (38l) are divided into two groups of three, all coaxially sleeved on the outside of the corresponding transmission rod (38b), and fixed to the support frame via a copper column base (38h), a copper column (38i), an electromagnetic coil connecting plate (38j), and an electromagnetic coil seat (38k). When the permanent magnet (38c) reciprocates with the transmission rod (38b), it cuts the magnetic field lines of the electromagnetic coil (38l) to generate electrical energy.

8. The variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to claim 6, characterized in that, The support frame of the TENG-EMG power generation module (3) includes a front mounting plate (32), a middle partition plate (34), a rear fixing plate (37), and the guide optical axis (36); the front mounting plate (32), the middle partition plate (34), and the rear fixing plate (37) are arranged in parallel, and the two ends of the guide optical axis (36) are fixed to the front mounting plate (32) and the rear fixing plate (37) respectively.

9. The variable cross-sectional area friction-electromagnetic composite power generation raft buoy according to claim 1, characterized in that, The front end of the raft shell (1) is also fixed with a hinge connector (5), and multiple raft buoys are sequentially hinged through the hinge connector (5) to form an expandable raft power generation array.

10. A method for energy conversion and adaptive control of a variable cross-sectional area friction-electromagnetic composite power generation raft buoy as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. The intelligent control system automatically adjusts the sampling frequency of the wave sensor according to the current wave and sea conditions, and periodically collects real-time wave frequency data at preset time intervals. S2. Based on the collected real-time wave frequency data, an intelligent prediction algorithm is used to predict the short-term wave frequency; S3. If the predicted wave frequency exceeds the preset safe operating frequency range, the system immediately enters the protection mode: the linear motor (23) of the control variable cross-sectional area mechanism (2) drives the moving cavity (22) to shrink the raft to the minimum width and cut off the power generation output circuit to stop power generation. S4. If the predicted wave frequency is within the preset safe operating frequency range, the corresponding optimal raft width is matched from the pre-built frequency-optimal width matching database. The database is based on the raft pitching motion equation and resonance tuning principle to pre-calibrate the correspondence between wave frequency and raft width under different sea conditions. S5. Detect the actual width of the current raft. If it is inconsistent with the optimal width, control the linear motor (23) of the variable cross-sectional area mechanism (2) to synchronously drive the moving cavity (22) to move and adjust the width of the raft to the optimal width. S6. Repeat steps S2 to S5 at preset time intervals to achieve dynamic tracking and adaptive control of the raft's natural pitching frequency on the real-time wave frequency. S7. The raft generates a pitching resonance motion with the waves. The mechanical energy is transmitted to the hydraulic pressure converter (33) of the TENG-EMG power generation module (3) through the hydraulic transmission module (4). The first frequency of the telescopic motion is output through the dual transmission module (31) to drive the TENG power generation unit to generate electricity, and the second frequency of the rotation-linear reciprocating motion is output to drive the EMG power generation unit to generate electricity, thus completing the composite conversion of wave energy to electrical energy.

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