Adaptive variable steady wave energy power generation device and working method thereof

Abstract

The application relates to a self-adaptive variable steady-state wave energy power generation device and a working method thereof, and belongs to the technical field of energy collection. The device comprises a float, a float guide column, an upper shell, a middle shell, a lower shell, a float connecting rod, a double-rod connector, a center rod, a guide fixer, a lead screw, a motor, a hydraulic PTO system, a hydraulic rod connector, a floating body, a center permanent magnet, a ring coil box, an upper cover plate and an excitation current generating device. The device can quickly change the buoyancy of the float according to the size of external wave excitation, effectively improves the reliability and response speed of the device, and improves the power generation efficiency of the wave energy power generation device. The device has both active and passive modes, realizes the change between multiple steady states and the change of the nonlinear characteristics of the magnetic multiple steady states, better adapts to the change of wave parameters, enables the device to efficiently capture wave energy under low-frequency conditions, and improves the wideband power generation efficiency of the wave energy power generation device.

Description

Technical Field

[0001] This invention relates to an adaptive variable steady-state wave energy generation device and its operating method, belonging to the field of energy harvesting technology. Background Technology

[0002] In recent decades, excessive carbon dioxide emissions have exacerbated climate-related problems and challenges and accelerated global warming. More and more countries and cities are joining the ranks of those striving for net-zero carbon dioxide or greenhouse gas emissions. Developing renewable energy and increasing the share of green energy are crucial for achieving net-zero emissions targets. Among numerous renewable energy sources, wave energy offers higher power density, better availability, and greater predictability, demonstrating significant carbon reduction potential.

[0003] The fundamental principle of wave energy generation devices is to utilize the impact of waves to convert wave energy into mechanical energy of an energy-capturing mechanism, and then use a power conversion system (PTO) to convert the mechanical energy into electrical energy. Traditional linear wave energy conversion devices can only generate high output power in a relatively narrow frequency band. For wave energy generation devices of a fixed size, it is difficult for their energy-capturing frequency band to coincide with the main spectrum of ocean waves, resulting in most of the wave energy remaining unutilized. Therefore, further broadening the operating frequency band of wave energy generation devices and enabling them to be applied to vibration excitation at different frequencies has become a focus of recent technological research.

[0004] Inspired by nonlinear energy harvesters, nonlinear multistable passive tuning methods have been applied to wave energy generation devices, improving their effective operating bandwidth and energy output efficiency. The basic principle is to alter the system's stiffness and the number of equilibrium points through nonlinear restoring forces, thereby promoting the formation of different potential wells and exhibiting multistable characteristics. Potential barriers exist between different potential wells; under sufficient external energy excitation, the system can overcome these barriers and oscillate back and forth between different equilibrium points, a state known as inter-well motion. Inter-well motion exhibits large amplitude and high energy, thus considered an ideal and efficient energy output method. Existing bistable broadband energy harvesters only lower the potential barriers but do not increase the distance between the outermost potential wells. To further improve output performance, it is necessary to construct multistable systems, such as tristable and tetrastable systems.

[0005] Currently, most wave energy generation devices operate in a single steady state. Even those with bistable systems cannot automatically change the number of steady states during operation, nor can they flexibly alter the nonlinear characteristics of multi-steady-state systems. For example, patent application number 202111008672.3 discloses an enhanced multi-steady-state broadband vibration energy harvesting device that can change the number of steady states by disassembling and reassembling the magnetic rings. However, using this method in real-world environments is not only very time-consuming but also increases the difficulty of changing steady states in certain specific operating conditions, such as when the magnetic rings are difficult to disassemble and reassemble in harsh sea conditions. Another example is patent application number 202211032770.5, which discloses a bistable magnetic levitation electromagnetic vibration energy harvester. By changing the fixed positions of the top and bottom sleeves, the distance between the first and second annular magnets can be altered, resulting in a bistable structure with different nonlinear characteristics. However, it cannot autonomously change the nonlinear characteristics of the steady-state structure during operation, thus remaining a limitation.

[0006] Therefore, when faced with uncertain sea conditions, relying solely on wave energy power generation devices with a single steady state or fixed multi-steady nonlinear characteristics cannot adequately adapt to the range of wave frequency variations in the ocean, making it difficult to solve the problem of generally low energy capture efficiency of wave energy power generation devices. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides an adaptive variable steady-state wave energy generation device and its operating method. This device can rapidly change the buoyancy of the pontoon according to the magnitude of external wave excitation, effectively improving both the device's reliability and response speed, as well as its power generation efficiency. It also features both active and passive modes, enabling transitions between multiple steady states and alterations to the nonlinear characteristics of magnetic multistable states. This allows for better adaptation to changes in wave parameters, enabling the device to efficiently capture wave energy under low-frequency conditions and improving the broadband power generation efficiency of the wave energy generation device.

[0008] The technical solution of the present invention is as follows:

[0009] On one hand, the present invention provides an adaptive variable steady-state wave energy generation device, including a float, a float guide column, an upper shell, an intermediate shell, a lower shell, a float connecting rod, a double rod connector, a central rod, a guide fixer, a lead screw, a motor, a hydraulic PTO system, a hydraulic rod connector, a float body, a central permanent magnet, an annular coil box, an upper cover plate, and an excitation current generating device;

[0010] The cavity of the wave energy power generation device consists of an upper cover plate, an upper shell, an intermediate shell, and a lower shell arranged from top to bottom. The upper cover plate is fixedly connected to the upper shell by bolts. The upper shell is fixedly connected to the float, the float is fixedly connected to the intermediate shell, and the intermediate shell is fixedly connected to the lower shell by bolts.

[0011] The pontoon guide post is fixedly connected to the upper shell by bolts through a guide fixing device. The pontoon and the pontoon guide post are slidably connected. The pontoon can move up and down along the pontoon guide post. An oil bladder is provided at the bottom of the pontoon. The lower shell is fixedly connected to the damping disc by bolts. The top of the pontoon is fixedly connected to the pontoon connecting rod. The pontoon connecting rod is fixedly connected to the double rod connector by bolts. The double rod connector is fixedly connected to the center rod by bolts.

[0012] The wave energy generator has a guide rail installed inside its cavity. The guide rail is slidably connected to a ring coil box. The ring coil box has a threaded through hole that engages with a lead screw. A motor is installed at the bottom of the lead screw. Under the action of the motor and the lead screw, the ring coil box can slide up and down on the guide rail. The number of ring coil boxes is preferably one or more.

[0013] The central permanent magnet is fixedly connected to the central rod, the central rod is fixedly connected to the hydraulic rod connector, and the hydraulic rod connector is fixedly connected to the hydraulic rod of the hydraulic PTO system by bolts. The hydraulic PTO system can drive the hydraulic rod to move up and down.

[0014] Inside the lower housing, an excitation current generating device is connected to the bottom of the central rod to generate an excitation current.

[0015] Preferably, there are two annular coil boxes. The uppermost annular coil box is connected to the upper cover plate by a spring. The upper and lower ends of the spring are welded with transition plates. The transition plates are fixedly connected to the annular coil box and the upper housing by bolts. The lower annular coil box is controlled only by a motor and a lead screw and is only connected to the lead screw. Only half of the lead screw is threaded. One lead screw controls one annular coil box.

[0016] Preferably, the excitation current generating device comprises two sets, including gears, racks, couplings, generators, square housings, one-way bearings, gearboxes, drive shafts, and drive shaft supports. The central rod is fixedly connected to the two racks by bolts, and each rack is connected to a gear. The gears are connected to the one-way bearings by keys and keyways, and the one-way bearings are connected to the drive shaft by keys and keyways. The drive shaft, coupling, gearbox, and generator are connected in sequence.

[0017] Preferably, the oil bladder is provided with a partition and an energy storage spring. The oil bladder is connected to the oil tank through a two-position two-way solenoid valve. The oil bladder is connected to the hydraulic pump through another two-position two-way solenoid valve. The hydraulic pump is connected to the oil tank and the safety valve respectively.

[0018] When the hydraulic pump pumps hydraulic oil into the oil bladder, the energy storage spring is compressed. When the oil bladder does not need to be filled with oil, the two-position two-way solenoid directional valve is opened, and the oil can be discharged directly through the energy storage spring without having to turn on the hydraulic pump again.

[0019] On the other hand, the present invention provides a working method for the above-mentioned adaptive variable steady-state wave energy generation device. When affected by waves, the float will move up and down along the float guide column with the wave undulation. The bottom of the float is connected to the oil bladder. Hydraulic oil can be pumped into or out of the oil bladder as needed to change the buoyancy of the float and thus change the response speed of the float to wave excitation.

[0020] When wave excitation is low, the oil in the oil bladder is returned to the oil tank to increase the buoyancy of the float, which can improve the power generation efficiency of the device. When dealing with severe weather at sea, the oil is discharged into the oil bladder to increase the weight of the oil bladder and improve the stability of the device, which can effectively avoid damage to the device from extreme weather.

[0021] When the pontoon moves up and down along the pontoon guide column, it drives the central rod to move up and down. The central rod transmits the motion to the rack, which drives the gear to rotate. Finally, the rotational motion is transmitted to the generator through the transmission shaft, coupling and gearbox, thereby generating excitation current. After the current is rectified and boosted, a stable excitation current is output.

[0022] If the generated stable excitation current is passed into one of the ring coil boxes, the coil will form a magnetic field opposite to that of the central permanent magnet. The central permanent magnet will be affected by the magnetic field of the coil. Under the combined influence of the magnetic force generated by the magnetic field of the coil and the buoyancy of the float in the seawater, the central permanent magnet can be made to achieve a stable state in two positions, that is, the buoyancy and magnetic force on the central rod are balanced, forming a bistable system.

[0023] If the generated stable excitation current is passed into the two ring coil boxes, the magnetic force generated under the action of the coil magnetic field and the buoyancy of the floating body in the seawater can be combined to make the central permanent magnet stable in three positions, that is, to form a tristable system.

[0024] If the generated stable excitation current is not passed to any toroidal coil box, an ideal stable current can also be generated simply by rectification and voltage boosting.

[0025] Preferably, the system uses a wave sensor (to measure wave height) and an acceleration sensor (to measure buoyancy; the greater the buoyancy, the greater the acceleration) to simultaneously determine the magnitude of wave excitation. When the displacement of the float caused by the wave does not exceed 2 / 3 of the length of the float guide column, it can be determined that the wave excitation is small. If it exceeds 2 / 3, the system must supply oil to the oil bladder. The amount of oil supplied is determined by the two sensors.

[0026] Preferably, under the action of waves, the rack moves up and down with the waves. The gear engages with the rack, and the gear also engages with the drive shaft through a one-way bearing. When the rack moves upward, the one-way bearing of one set of excitation current generating devices locks, transmitting the motion to the generator through the drive shaft. When the rack moves downward, the one-way bearing can rotate freely without transmitting motion. For the other set of excitation current generating devices, when the rack moves upward, the one-way bearing can rotate freely without transmitting motion, and when the rack moves downward, the one-way bearing locks, transmitting the motion to the generator through the drive shaft. Regardless of the direction of the rack's movement, at most one gear engages with the rack at any given time.

[0027] The most important components in the aforementioned power transmission process are two gears, two racks, and two one-way bearings. Unlike traditional gear and rack mechanisms, the two gears are mounted on the output shaft using two one-way bearings, with each bearing allowing motion to be transmitted in only one direction. Through the engagement and disengagement of the one-way bearings, regardless of the direction of rack movement, at most only one pinion is engaged with the output shaft at any given time.

[0028] Preferably, when the rotational speed of the drive shaft is higher than the input speed of the gears, both gears disengage from the rack, meaning there is no engagement, and the drive shaft can continue to maintain a certain speed for output rotation. When the rack is close to the critical position (the critical position is at the junction of upward and downward movement, where the speed is 0), the rack speed is already low. Without a one-way bearing, this would also result in a low output rotational speed. However, if the rotational speed of the drive shaft is higher than that of the gears, the one-way bearing can rotate freely, allowing the drive shaft to continue to maintain a certain speed for output rotation. The function of the gearbox is to change the transmission ratio and increase the rotational speed.

[0029] Preferably, in a multistable system, the nonlinear characteristics of the system can be altered by changing the magnitude of the excitation current flowing into the toroidal coil box. These nonlinear characteristics refer to the nonlinear force exerted on the central permanent magnet by the toroidal coil box. By changing the system's stiffness and the number of equilibrium points through the nonlinear restoring force, different potential wells can be formed, thus promoting the system to exhibit multistable characteristics.

[0030] In bistable and tristable systems, the position of the ring coil box can be flexibly adjusted through the combined action of spring, motor, lead screw and guide rail. When the motor is not started, the uppermost ring coil box can be moved on the lead screw by the force of the spring alone. However, its disadvantage is that when the spring returns to its original length, the ring coil box will only move up and down in a small range under the magnetic force generated by the central permanent magnet, and cannot flexibly change its position according to the waves.

[0031] Furthermore, while changing the position of the annular coil box, the spring can store a certain amount of energy. When the motor is off, the spring can again change the position of the uppermost annular coil box, enabling the wave energy generator to actively and passively change the position of the annular coil box, thereby altering the multistable position of the wave energy generator and flexibly changing the potential barrier. The potential barrier can be changed by adjusting the distance between the two annular coil boxes and altering the current flowing through them; the transition from a bistable to a tristable state can also lower the potential barrier. The potential barrier is the potential energy difference between two potential wells. The larger the potential barrier, the higher the energy required for movement between the wells; conversely, the smaller the barrier, the lower the energy required. By changing the potential barrier, energy capture efficiency can be improved, making it more adaptable to wave frequencies, achieving efficient energy capture in low-frequency wave conditions, and enabling broadband high-efficiency power generation.

[0032] For any details not covered in this invention, please refer to the prior art.

[0033] The beneficial effects of this invention are as follows:

[0034] This invention allows for flexible adjustment of the buoyant's weight via an oil bladder. When wave excitation is low, oil from the bladder is returned to the fuel tank to increase buoyancy and improve the device's power generation efficiency. Furthermore, in the event of severe weather at sea, oil is pumped into the bladder to reduce its weight, effectively preventing damage to the device from extreme weather conditions.

[0035] By combining two gears, two racks, and two one-way bearings, the motion of the undulating waves can be fully utilized. Each one-way bearing only allows motion to be transmitted in one direction. Through the engagement and disengagement of the one-way bearings, no matter which direction the rack moves, at most only one gear can be engaged with the output shaft at any given time. When the rotational speed of the output shaft is higher than the input speed of the gears, both gears will disengage, thus protecting the device.

[0036] By applying excitation current to different coils, variations between multiple steady states can be achieved. Through the coordination of springs, lead screws, motors, and tracks, the position of the coils can be actively or passively changed in the wave energy generation device. By altering the magnitude of the excitation current flowing into the toroidal coil box and the position within the toroidal coil box, various nonlinear characteristics of multiple steady states can be achieved. This allows for flexible modification of the device's potential barrier, broadening the resonant frequency range, improving energy capture efficiency, and better adapting to wave frequencies. It enables efficient energy capture in low-frequency wave conditions and achieves broadband, high-efficiency power generation. Attached Figure Description

[0037] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0038] Figure 1This is a schematic diagram of the overall structure of the adaptive wave energy variable steady-state wave energy power generation device of the present invention.

[0039] Figure 2 This is a schematic diagram of the internal structure of the cavity of the adaptive wave energy variable steady-state wave energy power generation device of the present invention;

[0040] Figure 3 This is a schematic diagram of the excitation current generating device of the adaptive wave energy variable steady-state wave energy power generation device of the present invention.

[0041] Figure 4 This is a schematic diagram of the stable position of the bistable system of the adaptive wave energy variable steady-state wave energy power generation device of the present invention; where (a) and (b) are two steady-state positions, respectively;

[0042] Figure 5 This is a schematic diagram of the stable position of the three-steady-state system of the adaptive wave energy variable steady-state wave energy power generation device of the present invention; wherein (a), (b), and (c) are three steady-state positions, respectively;

[0043] Figure 6 This is a schematic diagram of the working principle of the oil bladder of the adaptive wave energy variable steady-state wave energy power generation device of the present invention;

[0044] Figure 7 This is a flowchart illustrating the working process of the adaptive wave energy variable steady-state wave energy power generation device of the present invention.

[0045] In the diagram, 1-buoy, 2-buoy guide post, 3-intermediate shell, 4-lower shell, 5-upper shell, 6-oil bladder, 7-buoy connecting rod, 8-double rod connector, 9-center rod, 10-guide retainer, 11-spring, 12-screw, 13-motor, 14-hydraulic PTO system, 15-hydraulic rod connector, 16-buoy, 17-central permanent magnet, 18-ring coil box, 19-upper cover plate, 20-gear, 21-coupling, 22-generator, 23-square shell, 24-one-way bearing, 25-gearbox, 26-drive shaft, 27-drive shaft support, 28-rack, 29-partition plate, 30-safety valve, 31-hydraulic pump, 32-oil tank, 33-two-position two-way solenoid directional valve, 34-energy storage spring. Detailed Implementation

[0046] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. However, this is not the only description; all aspects not described in detail herein are based on conventional techniques in the art.

[0047] Example 1

[0048] An adaptive variable steady-state wave energy generation device includes a float 1, a float guide column 2, an upper shell 5, an intermediate shell 3, a lower shell 4, a float connecting rod 7, a double rod connector 8, a central rod 9, a guide fixer 10, a lead screw 12, a motor 13, a hydraulic PTO system 14, a hydraulic rod connector 15, a float 16, a central permanent magnet 17, a ring coil box 18, an upper cover plate 19, and an excitation current generating device;

[0049] The cavity of the wave energy power generation device consists of an upper cover plate 19, an upper shell 5, an intermediate shell 3, and a lower shell 4 arranged sequentially from top to bottom. The upper cover plate is fixedly connected to the upper shell 5 by bolts. The upper shell 5 is fixedly connected to the float 16, the float 16 is fixedly connected to the intermediate shell 3, and the intermediate shell 3 is fixedly connected to the lower shell 4 by bolts.

[0050] The pontoon guide post 2 is fixedly connected to the upper shell 5 by bolts through the guide fixing device 10. The pontoon 1 is slidably connected to the pontoon guide post 2. The pontoon 1 can move up and down along the pontoon guide post 2. An oil bladder 6 is provided at the bottom of the pontoon 1. The lower shell 4 is fixedly connected to the damping disc by bolts. The top of the pontoon 1 is fixedly connected to the pontoon connecting rod 7. The pontoon connecting rod 7 is fixedly connected to the double rod connector 8 by bolts. The double rod connector 8 is fixedly connected to the center rod 9 by bolts.

[0051] The inner side of the wave energy generator is equipped with a guide rail, which is slidably connected to the annular coil box 18. The annular coil box 18 is provided with a threaded through hole, which is engaged with the lead screw 12. A motor 13 is provided at the bottom of the lead screw 12. Under the action of the motor 13 and the lead screw 12, the annular coil box 18 can slide up and down on the guide rail. The number of annular coil boxes 18 is preferably one or more.

[0052] The central permanent magnet 17 is fixedly connected to the central rod 9, the central rod 9 is fixedly connected to the hydraulic rod connector 15, and the hydraulic rod connector 15 is fixedly connected to the hydraulic rod of the hydraulic PTO system 14 by bolts. The hydraulic PTO system 14 can drive the hydraulic rod to move up and down.

[0053] Inside the lower housing, the bottom of the central rod 9 is connected to an excitation current generating device for generating excitation current.

[0054] Example 2

[0055] An adaptive variable steady-state wave energy generation device, as described in Embodiment 1, differs in that there are two annular coil boxes 18. The uppermost annular coil box is connected to the upper cover plate by a spring 11. The upper and lower ends of the spring 11 are welded with transition plates. The transition plates are fixedly connected to the annular coil box and the upper shell by bolts. The lower annular coil box is controlled only by a motor and a lead screw and is only connected to the lead screw. Only half of the lead screw is threaded, and one lead screw controls one annular coil box.

[0056] Example 3

[0057] An adaptive variable steady-state wave energy generation device, as described in Example 2, except that, as Figure 3 As shown, the excitation current generating device includes two sets, including gear 20, rack 28, coupling 21, generator 22, square housing 23, one-way bearing 24, gearbox 25, drive shaft 26 and drive shaft support 27. The central rod 9 is fixedly connected to the two racks 28 by bolts, and each rack 28 is connected to a gear 20. The gear 20 is connected to the one-way bearing 24 by a key and keyway, and the one-way bearing 24 is connected to the drive shaft 26 by a key and keyway. The drive shaft, coupling, gearbox and generator are connected in sequence.

[0058] Example 4

[0059] An adaptive variable steady-state wave energy generation device, as described in Example 3, except that, as Figure 6 As shown, the oil bladder 6 is equipped with a partition 29 and an energy storage spring 34. The oil bladder 6 is connected to the oil tank 32 through a two-position two-way solenoid valve 33. The oil bladder 6 is connected to the hydraulic pump 31 through another two-position two-way solenoid valve. The hydraulic pump 31 is connected to the oil tank and the safety valve 30 respectively.

[0060] When the hydraulic pump 31 discharges hydraulic oil into the oil bladder 32, the energy storage spring 34 is compressed; when the oil bladder 6 does not need to be filled with oil, the two-position two-way solenoid directional valve is opened, and the oil can be discharged directly through the energy storage spring without having to turn on the hydraulic pump again.

[0061] Example 5

[0062] An adaptive variable steady-state wave energy generation device operates as follows: when affected by waves, the float 1 moves up and down along the float guide column 2 with the wave undulation. The bottom of the float 1 is connected to the oil bladder 6. Hydraulic oil can be pumped into or out of the oil bladder by the hydraulic pump 31 as needed to change the buoyancy of the float 1 and thus change the response speed of the float to wave excitation.

[0063] When wave excitation is low, the oil in oil bladder 6 is returned to the oil tank to increase the buoyancy of the float, which can improve the power generation efficiency of the device; while in response to severe weather at sea, the oil is discharged into the oil bladder, such as... Figure 6 As shown, the left two-position two-way solenoid directional valve is in the open position, and the right two-position two-way solenoid directional valve is in the closed position. The hydraulic pump pumps oil into the oil bladder, increasing the weight of the oil bladder and improving the stability of the device. This can effectively prevent damage to the device from extreme weather.

[0064] When the float 1 moves up and down along the float guide column 2, it drives the center rod 9 to move up and down. The center rod 9 transmits the motion to the rack 28, the rack 28 drives the gear 20 to rotate, and finally transmits the rotational motion to the generator 22 through the transmission shaft, coupling and gearbox, thereby generating an excitation current. After the current is rectified and boosted, a stable excitation current is output.

[0065] If the generated stable excitation current is passed into one of the ring coil boxes, causing the coil to form a magnetic field opposite to that of the central permanent magnet 17, the central permanent magnet 17 will be affected by the magnetic field of the coil. Under the combined influence of the magnetic force generated by the coil magnetic field and the buoyancy of the float in seawater, the central permanent magnet 17 can achieve a stable state in two positions, that is, the buoyancy and magnetic force on the central rod are balanced, forming a bistable system, such as... Figure 4 As shown;

[0066] If the generated stable excitation current is passed through the two ring coil boxes 18, the magnetic force generated under the action of the coil magnetic field and the buoyancy of the float in seawater can jointly induce the central permanent magnet to achieve a stable state in three positions, thus forming a tristable system. Figure 5 As shown;

[0067] If the generated stable excitation current is not passed to any toroidal coil box, an ideal stable current can also be generated simply by rectification and voltage boosting.

[0068] The system uses a wave sensor (to measure wave height) and an acceleration sensor (to measure buoyancy; the greater the buoyancy, the greater the acceleration) to simultaneously determine the magnitude of wave excitation. When the displacement of the float caused by the wave does not exceed 2 / 3 of the length of the float guide column, it can be determined that the wave excitation is small. If it exceeds 2 / 3, the system must supply oil to the oil bladder. The amount of oil supplied is determined by the two sensors.

[0069] Under the influence of waves, rack 28 moves up and down with the waves. Gear 20 engages with rack 28, and gear 20 engages with drive shaft 26 through one-way bearing 24. When rack 28 moves upward, one-way bearing 24 of one set of excitation current generating device locks, transmitting the motion to generator 22 through drive shaft. When rack 28 moves downward, one-way bearing 24 can rotate freely and does not transmit motion. For another set of excitation current generating device, when rack moves upward, one-way bearing can rotate freely and does not transmit motion; when rack moves downward, one-way bearing locks, transmitting the motion to generator 22 through drive shaft. Regardless of the direction of rack movement, at most only one gear meshes with rack at any given time.

[0070] The most important components in the aforementioned power transmission process are two gears, two racks, and two one-way bearings. Unlike traditional gear and rack mechanisms, the two gears are mounted on the output shaft using two one-way bearings, with each bearing allowing motion to be transmitted in only one direction. Through the engagement and disengagement of the one-way bearings, regardless of the direction of rack movement, at most only one pinion is engaged with the output shaft at any given time.

[0071] When the rotational speed of the drive shaft exceeds the input speed of the gears, both gears disengage from the rack, meaning they no longer engage, and the drive shaft can continue to maintain a certain speed for output. When the rack is close to its critical position (the critical position is at the junction of upward and downward movement, where the speed is 0), the rack speed is already low. Without a one-way bearing, this would also result in a lower output rotational speed. However, if the drive shaft's rotational speed is higher than the gears' speed, the one-way bearing can rotate freely, allowing the drive shaft to continue maintaining a certain speed for output. The function of the gearbox is to change the transmission ratio and increase the rotational speed.

[0072] Example 6

[0073] An adaptive variable steady-state wave energy generation device is described in Example 5, except that in the multi-stable system, the nonlinear characteristics of the multi-stable system can be altered by changing the magnitude of the excitation current leading to the annular coil box 18. The nonlinear characteristics refer to the nonlinear force provided by the annular coil box to the central permanent magnet. By changing the system's stiffness and the number of equilibrium points through the nonlinear restoring force, different potential wells are formed in the system, thus enabling it to exhibit multi-stable characteristics.

[0074] In bistable and tristable systems, the position of the annular coil box 18 can be flexibly adjusted through the combined action of spring 11, motor 13, lead screw 12 and guide rail. When the motor is not started, the uppermost annular coil box 18 can be moved on the lead screw 12 by the force of spring 11 alone. However, its disadvantage is that when the spring returns to its original length, the annular coil box 18 will only move up and down within a small range under the magnetic force generated by the central permanent magnet 17, and cannot flexibly change its position according to the waves.

[0075] Furthermore, while changing the position of the annular coil box 18, the spring 11 can store a certain amount of energy. When the motor 13 is turned off, the spring 11 can again change the position of the uppermost annular coil box 18, enabling the wave energy power generation device to actively and passively change the position of the annular coil box 18, thereby changing the multi-stable position of the wave energy power generation device and flexibly changing the potential barrier of the device. The potential barrier can be changed by adjusting the distance between the two annular coil boxes and changing the magnitude of the current flowing into the annular coil boxes. The conversion from bistable to tristable state can also reduce the potential barrier. The potential barrier is the potential energy difference between two potential wells. The larger the potential barrier, the higher the energy required to achieve movement between the wells; conversely, the smaller the barrier, the lower the energy required. By changing the potential barrier, the energy capture efficiency can be improved, making it more adaptable to wave frequencies, achieving efficient energy capture in low-frequency wave sea conditions, and enabling broadband efficient power generation.

[0076] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An adaptive variable steady-state wave energy generation device, characterized in that, It includes a pontoon, a pontoon guide post, an upper shell, an intermediate shell, a lower shell, a pontoon connecting rod, a double rod connector, a center rod, a guide fixer, a lead screw, a motor, a hydraulic PTO system, a hydraulic rod connector, a float, a central permanent magnet, a ring coil box, an upper cover plate, and an excitation current generating device; The cavity of the wave energy power generation device consists of an upper cover plate, an upper shell, an intermediate shell, and a lower shell arranged from top to bottom. The upper cover plate is fixedly connected to the upper shell by bolts. The upper shell is fixedly connected to the float, the float is fixedly connected to the intermediate shell, and the intermediate shell is fixedly connected to the lower shell by bolts. The pontoon guide post is fixedly connected to the upper shell via a guide fixing device. The pontoon is slidably connected to the pontoon guide post, and the pontoon can move up and down along the pontoon guide post. An oil bladder is provided at the bottom of the pontoon. The lower shell is fixedly connected to the damping disc via bolts. The top of the pontoon is fixedly connected to the pontoon connecting rod, which is fixedly connected to the double rod connector. The double rod connector is fixedly connected to the center rod via bolts. The inner side of the wave energy power generation device is equipped with a guide rail, which is slidably connected to the annular coil box. The annular coil box is provided with a threaded through hole, which is engaged with a lead screw. A motor is installed at the bottom of the lead screw. Under the action of the motor and the lead screw, the annular coil box can slide up and down on the guide rail. The central permanent magnet is fixedly connected to the central rod, the central rod is fixedly connected to the hydraulic rod connector, and the hydraulic rod connector is fixedly connected to the hydraulic rod of the hydraulic PTO system by bolts. The hydraulic PTO system can drive the hydraulic rod to move up and down. Inside the lower housing, an excitation current generating device is connected to the bottom of the central rod to generate an excitation current. By changing the magnitude of the excitation current leading to the ring coil box, the nonlinear characteristics of the multistable system can be altered. The nonlinear characteristics refer to the nonlinear force provided by the ring coil box to the central permanent magnet. By changing the stiffness and the number of equilibrium points of the system through the nonlinear restoring force, the system can be promoted to form different potential wells, thus exhibiting multistable characteristics.

2. The adaptive variable steady-state wave energy generation device according to claim 1, characterized in that, There are two annular coil boxes, with the uppermost annular coil box connected to the top cover plate by a spring.

3. The adaptive variable steady-state wave energy generation device according to claim 1, characterized in that, The excitation current generating device includes two sets, comprising gears, racks, couplings, generators, square housings, one-way bearings, gearboxes, drive shafts, and drive shaft supports. The central rod is fixedly connected to the two racks by bolts, and each rack is connected to a gear. The gears are connected to the one-way bearings by keys and keyways, and the one-way bearings are connected to the drive shaft by keys and keyways. The drive shaft, coupling, gearbox, and generator are connected in sequence.

4. The adaptive variable steady-state wave energy generation device according to claim 3, characterized in that, The oil bladder is equipped with a partition and an energy storage spring. The oil bladder is connected to the oil tank through a two-position two-way solenoid valve. The oil bladder is also connected to the hydraulic pump through another two-position two-way solenoid valve. The hydraulic pump is connected to the oil tank and the safety valve respectively. When the hydraulic pump discharges hydraulic oil into the oil bladder, the energy storage spring is compressed; when the oil bladder does not need to be filled with oil, the two-position two-way solenoid directional valve is opened, and the oil is discharged directly through the energy storage spring without having to turn on the hydraulic pump again.

5. A method for operating the adaptive variable steady-state wave energy generation device according to claim 4, characterized in that, When affected by waves, the pontoon moves up and down along the pontoon guide column with the undulation of the waves. The bottom of the pontoon is connected to the oil bladder. As needed, hydraulic oil is pumped into or out of the oil bladder by a hydraulic pump to change the buoyancy of the pontoon, thereby changing the pontoon's response speed to wave excitation. When wave excitation is low, the oil in the oil bladder is returned to the oil tank to increase the buoyancy of the float, which can improve the power generation efficiency of the device. When dealing with severe weather at sea, the oil is discharged into the oil bladder to increase the weight of the oil bladder, improve the stability of the device, and effectively avoid damage to the device from extreme weather. When the pontoon moves up and down along the pontoon guide column, it drives the central rod to move up and down. The central rod transmits the motion to the rack, which drives the gear to rotate. Finally, the rotational motion is transmitted to the generator through the transmission shaft, coupling and gearbox, thereby generating excitation current. After the current is rectified and boosted, a stable excitation current is output. If the generated stable excitation current is passed into one of the ring coil boxes, the coil will form a magnetic field opposite to that of the central permanent magnet. The central permanent magnet will be affected by the magnetic field of the coil. Under the combined influence of the magnetic force generated by the magnetic field of the coil and the buoyancy of the float in the seawater, the central permanent magnet will be in a stable state in two positions, that is, the buoyancy and magnetic force on the central rod are in balance, forming a bistable system. If the generated stable excitation current is passed into the two ring coil boxes, the magnetic force generated under the action of the coil magnetic field and the buoyancy of the float in the seawater will cause the central permanent magnet to achieve a stable state in three positions, thus forming a tristable system.

6. The operating method of the adaptive variable steady-state wave energy generation device according to claim 5, characterized in that, When the displacement of the buoy caused by the wave does not exceed 2 / 3 of the length of the buoy guide column, it is determined that the wave excitation is small; if it exceeds 2 / 3, oil is supplied to the oil bladder.

7. The operating method of the adaptive variable steady-state wave energy generation device according to claim 5, characterized in that, Under the influence of waves, the rack moves up and down with the waves. The gear engages with the rack, and the gear also engages with the drive shaft through a one-way bearing. When the rack moves upward, the one-way bearing of one of the excitation current generating devices locks, transmitting the motion to the generator through the drive shaft. When the rack moves downward, the one-way bearing rotates freely and does not transmit motion. For the other excitation current generating device, when the rack moves upward, the one-way bearing rotates freely and does not transmit motion; when the rack moves downward, the one-way bearing locks, transmitting the motion to the generator through the drive shaft. Regardless of the direction the rack moves, at any given time, only one gear meshes with the rack.

8. The operating method of the adaptive variable steady-state wave energy generation device according to claim 7, characterized in that, When the rotational speed of the drive shaft is higher than the input speed of the gears, both gears disengage from the rack, meaning they no longer engage, and the drive shaft can continue to maintain a certain speed for output.

9. The operating method of the adaptive variable steady-state wave energy generation device according to claim 5, characterized in that, In a multistable system, the nonlinear characteristics of the multistable system can be altered by changing the magnitude of the excitation current leading to the toroidal coil box. In bistable and tristable systems, the position of the ring coil box can be flexibly adjusted through the cooperation of spring, motor, lead screw and guide rail. When the motor is not started, the uppermost ring coil box is moved on the lead screw by the force of the spring. When the spring returns to its original length, the ring coil box will only move up and down in a small range under the magnetic force generated by the central permanent magnet. Moreover, while changing the position of the annular coil box, the spring can store a certain amount of energy; when the motor is turned off, the spring can change the position of the uppermost annular coil box again, realizing the active and passive changes of the position of the annular coil box of the wave energy power generation device, thereby changing the multi-steady-state position of the wave energy power generation device, flexibly changing the potential barrier of the device, improving the energy capture efficiency, and being more adaptable to wave frequencies, achieving efficient energy capture in low-frequency wave sea conditions.

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