Self-powered Semi-Spar offshore wind turbine structure and its motion control device and method

Abstract

This invention discloses a self-powered Semi-Spar offshore wind turbine structure and its motion control device and method, belonging to the field of offshore wind power technology. It includes a detachable platform comprising a Semi-submersible platform and a Spar monopole platform. The Semi-submersible platform includes a float and a central cylinder, with the central cylinder positioned at the center of the Semi-submersible platform. A superstructure is located above the Spar monopole platform, which is situated at the center of the central cylinder. A motion control system and a power supply system are mounted on the detachable platform. This invention utilizes the aforementioned self-powered Semi-Spar offshore wind turbine structure and its motion control device and method. Through the detachable platform and the motion control system, motion suppression of the offshore wind turbine system is achieved, improving structural safety and reliability. Furthermore, a wave energy generator converts wave energy into electrical energy, enabling power supply even when the wind turbine is shut down, thus solving the problem of semi-active control and self-powered operation in extreme environments.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power technology, and in particular to the structure of the self-powered Semi-Spar offshore wind turbine and its motion control device and method. Background Technology

[0002] As the core equipment for offshore wind energy resource development, offshore wind turbines are continuously evolving towards larger sizes and deeper waters. With increasing distance from shore and greater water depth, floating platforms are gradually becoming the mainstream structural form supporting deep-sea wind turbines.

[0003] While existing technologies have explored basic structural forms, insufficient attention has been paid to structural vibration reduction design. Under the combined influence of complex multidirectional ocean currents and strong winds, energy dissipation efficiency is low, and some designs have limited buoyancy supply, resulting in severe structural vibrations. This makes the structure prone to dynamic instability and fatigue damage, seriously affecting safety and reliability. Furthermore, the enormous energy contained in waves is often simply regarded as a catastrophic load under extreme sea conditions, failing to be effectively converted and utilized. The energy supply problem during wind turbine shutdown has also not been addressed, leading to energy waste and operational shortcomings.

[0004] Therefore, there is an urgent need for a reliable, durable offshore wind turbine structure with energy recovery capabilities. Summary of the Invention

[0005] The purpose of this invention is to provide a self-powered Semi-Spar offshore wind turbine structure and its motion control device and method. By cooperating with the Semi semi-submersible platform and the Spar monopole platform in the separate platform, and with the addition of a motion control system, the motion of the offshore wind turbine system is suppressed, dynamic instability and fatigue damage are reduced, and the structural safety and reliability are improved. Wave energy is converted into electrical energy through wave energy power generation device and energy storage and power supply device to provide power to the wind turbine when it is shut down.

[0006] To achieve the above objectives, the present invention provides a self-powered Semi-Spar offshore wind turbine structure and its motion control device, comprising a detachable platform, wherein the detachable platform includes a Semi-submersible platform and a Spar monocoque platform, the Semi-submersible platform includes a float and a center tube, the center tube is located at the center of the Semi-submersible platform, a superstructure is provided above the Spar monocoque platform, the Spar monocoque platform is located at the center of the center tube, and a motion control system and a power supply system are provided on the detachable platform.

[0007] Preferably, the upper structure includes a tower, which is disposed above the Spar single-column platform. A nacelle is disposed on the top of the tower, and a hub is disposed in the nacelle, with blades disposed on the hub.

[0008] Preferably, the motion control system includes a limiting device, a damping buffer device, a monitoring device, and a control device.

[0009] Preferably, the limiting device is disposed at both ends of the Spar single-column platform, the limiting device is provided with a mechanical stop device, the damping buffer device is disposed between the central cylinder and the Spar single-column platform, the monitoring device is disposed at both ends of the damping buffer device, the control device is connected to the monitoring device, and the damping buffer device is connected to the control device.

[0010] Preferably, the damping buffer device can be one or more of a buffer spring and a damper, and a rigid partition is provided at the upper end of the Spar single-column platform, and the control device is located on the rigid partition.

[0011] Preferably, the damper comprises a stator and a mover.

[0012] Preferably, the energy supply system includes a wave energy generation device and an energy storage and power supply device, wherein the wave energy generation device includes an electromagnetic induction generation device.

[0013] Preferably, the electromagnetic induction power generation device includes a coil and a permanent magnet. The coil is disposed on the outer surface of the Spar single-column platform, the permanent magnet is disposed on the inner surface of the central cylinder, and the energy storage and power supply device is disposed on the rigid partition.

[0014] Preferably, the coil is connected to the energy storage and power supply device via a wire, and the energy storage and power supply device is connected to the control device via a wire.

[0015] This invention relates to a self-powered Semi-Spar offshore wind turbine structure and its motion control method, comprising the following steps:

[0016] S1. The monitoring device monitors the velocities V1 of the semi-submersible platform and V2 of the single-column platform at both ends of the damper, thereby obtaining the relative velocities at both ends of the damper:

[0017] U = V1 - V2;

[0018] S2. The control device calculates the product of the two speed signals:

[0019] V1×U;

[0020] And determine whether the result is greater than 0. If it is, the direction of the damping force is consistent with the direction of the expected control force, the damper works, and the kinetic energy of the object is effectively dissipated. Then jump to S3. If not, the damper does not work. Then jump to S1.

[0021] S3. Calculate the desired control force:

[0022] T = -C × V1;

[0023] Where C is the desired control damping coefficient, and the negative sign indicates that the direction of the desired control force is opposite to the direction of the velocity V1 of the Semi-submersible platform.

[0024] S4. The damper starts working. Determine the damper's operating parameters, including the number of units started, the actual damping coefficient, and the actual damping force F:

[0025] F = μ × U;

[0026] Where μ is the damping coefficient;

[0027] S5. The monitoring device continues to collect data and determines whether the platform movement has returned to normal working state. If not, it jumps to S3; if yes, it ends.

[0028] Therefore, this invention adopts the above-mentioned autonomous power supply Semi-Spar offshore wind turbine structure and its motion control device and method. Through the cooperation of the Semi semi-submersible platform and the Spar single-column platform in the separated platform, plus the motion control system, the motion suppression of the offshore wind turbine system is achieved, reducing dynamic instability and fatigue damage, and improving structural safety and reliability. Through the wave energy power generation device and energy storage and power supply device, wave energy is converted into electrical energy, avoiding energy waste, and realizing power supply in the wind turbine shutdown state, solving the problem of autonomous power supply in semi-active control under extreme environments.

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the self-powered Semi-Spar offshore wind turbine and its motion control device according to an embodiment of the present invention.

[0031] Figure 2 This is a schematic diagram of the offshore wind turbine split platform structure of an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control device of the present invention;

[0032] Figure 3 This is a schematic diagram illustrating the differences in the motion state of an offshore wind turbine under waves, based on the self-powered Semi-Spar offshore wind turbine structure and its motion control device of this invention.

[0033] Figure 4 This is a schematic diagram of the upper structure of the offshore wind turbine according to an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control device of the present invention;

[0034] Figure 5This is a schematic diagram of the motion control system structure of an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control device of the present invention;

[0035] Figure 6 This is a schematic diagram of the limiting device structure of an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control device of the present invention;

[0036] Figure 7 This is a schematic diagram of the damper structure of an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control device of the present invention.

[0037] Figure 8 This is a schematic diagram of the buffer spring structure of an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control device of the present invention;

[0038] Figure 9 This is a schematic diagram of the overall structure of the power generation device in an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control device of the present invention;

[0039] Figure 10 This is a schematic diagram of the electromagnetic induction power generation device of an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control device of the present invention.

[0040] Figure 11 This is a logic flowchart of the motion control method of an embodiment of the self-powered Semi-Spar offshore wind turbine structure and its motion control method according to the present invention.

[0041] Figure Labels

[0042] 1. Superstructure; 101. Blade; 102. Nacelle; 103. Hub; 104. Tower; 2. Separable Platform; 201. Semi-submersible Platform; 202. Spar Single-Column Platform; 203. Center Tube; 204. Float; 3. Motion Control System; 301. Limiting Device; 301A. Mechanical Stop Device; 302. Damping Buffer Device; 303. Damper; 303A. Stator; 303B. Mover; 304. Buffer Spring; 305. Monitoring Device; 306. Control Device; 4. Power Supply System; 401. Wave Energy Generation Device; 402. Energy Storage and Power Supply Device; 403. Electromagnetic Induction Generation Device; 404. Coil; 405. Permanent Magnet; 406. Conductor; 407. Rigid Bulkhead. Detailed Implementation

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0044] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0045] Example 1

[0046] This invention provides a self-powered Semi-Spar offshore wind turbine structure and its motion control device, such as... Figure 1 Figure 2 As shown, the system includes a detachable platform 2, which comprises a semi-submersible platform 201 and a single-column platform 202. A superstructure 1 is provided above the single-column platform 202. The semi-submersible platform 201 includes a float 204 and a center tube 203. The center tube 203 is located in the center of the semi-submersible platform 201, and the single-column platform 202 is located in the center of the center tube 203. A motion control system 3 and a power supply system 4 are provided on the detachable platform 2.

[0047] The Semi-submersible platform 201 and the Spar single-column platform 202 are decoupled in the direction of heave motion, which can generate relative motion in the vertical direction.

[0048] In this embodiment, the height of the Spar monocoque platform 202 is 70m, which is shorter than that of a traditional Spar platform, reducing the amount of steel used and lowering material and manufacturing costs. The net distance between the float 204 of the semi-submersible platform 201 and the Spar monocoque platform 202 is designed to be 40m, placing it near half the wavelength of common waves. This design allows the semi-submersible platform 201 and the Spar monocoque platform 202 to be in a dynamic position with opposite phases at wave crests and troughs when waves pass over the platform.

[0049] like Figure 3As shown in the diagram, the left side depicts the Semi-submersible platform 201 at a wave trough, while the Spar monocoque platform 202 is at a wave crest, with Semi-submersible platform 201 positioned lower and Spar monocoque platform 202 higher. The right side depicts the Semi-submersible platform 201 at a wave crest and Spar monocoque platform 202 at a wave trough as the wave propagates, with Semi-submersible platform 201 higher and Spar monocoque platform 202 lower. Under half-wave motion, the overall behavior is that Semi-submersible platform 201 moves upward and Spar monocoque platform 202 moves downward, with their relative motion being the superposition of the two. This phase difference maximizes the relative displacement between the two platforms in the heave direction, thereby enhancing the operating stroke and energy capture efficiency of the wave energy harvesting device integrated between the two platforms.

[0050] like Figure 4 As shown, the superstructure 1 includes a tower 104, which is located above the Spar single-column platform 202. A nacelle 102 is located on the top of the tower 104, and a hub 103 is located in the nacelle 102. Blades 101 are located on the hub 103. The superstructure 1 is a traditional wind turbine structure used to generate electricity using sea wind.

[0051] like Figure 5 As shown, the motion control system 3 includes a limit device 301, a damping buffer device 302, a monitoring device 305, and a control device 306. For example... Figure 6 As shown, the limiting device 301 is installed at both ends of the Spar single-column platform 202 to prevent the Spar single-column platform 202 from structurally separating from the Semi semi-submersible platform 201. The limiting device 301 is equipped with a mechanical stop device 301A.

[0052] In this embodiment, the mechanical stop device 301A is made of Q355ND low alloy high strength steel and is connected to the top of the Spar single column platform 202 and 10 meters from the bottom by M30 grade 10.9 high strength bolts.

[0053] A damping buffer device 302 is disposed between the central cylinder 203 and the Spar single-column platform 202. A monitoring device 305 is disposed at both ends of the damping buffer device 302, with one end in contact with the surface of the Spar single-column platform 202 and the other end in contact with the surface of the central cylinder 203. The monitoring device 305 is used to monitor the relative velocity between the two ends of the damping buffer device 302 and the absolute velocity of the Semi semi-submersible platform 201. A control device 306 is connected to the monitoring device 305, and the damping buffer device 302 is connected to the control device 306.

[0054] A rigid partition 407 is installed at the upper part of the Spar single-column platform 202, and a control device 306 is mounted on the rigid partition 407. The control device 306 is configured as an industrial computer, which, through a built-in data acquisition and control system, monitors the real-time status of the Semi-submersible platform 201 and the Spar single-column platform 202 and executes corresponding control algorithms. Figure 7 , Figure 8 As shown, the damping buffer device 302 can be selected from one or more of the buffer spring 304 and the damper 303, and the damper 303 includes a stator 303A and a mover 303B.

[0055] In this embodiment, the buffer spring 304 is a corrosion-resistant helical compression spring. The spring wire is made of 06Cr17Ni12Mo2 with a wire diameter of 50mm, a spring mean diameter of 500mm, a free height of 1350mm, a maximum working compression stroke of 800mm, and a rated working load of ±1500kN. It is used to provide a passive control method. This selection of materials and parameters ensures that the buffer spring 304 possesses excellent corrosion fatigue resistance in high-salt and high-humidity marine environments and can withstand the enormous relative forces between platforms.

[0056] When the wind and wave load causes the Semi-submersible platform 201 and the Spar single-column platform 202 to move toward each other, the buffer spring 304 is compressed, and the elastic restoring force generated by it acts in the opposite direction on the two platforms to resist their relative approach. The whole process does not require external energy input, and the wave energy is dissipated entirely by the force deformation of the buffer spring 304 itself, thereby effectively suppressing the relative motion amplitude and vibration acceleration between the two platforms.

[0057] In this embodiment, the damper 303 is an eddy current damper, which mainly consists of a stator 303A and a mover 303B. The stator 303A is made of DT4C industrial pure iron material, which has high permeability and low coercivity characteristics, and can form a concentrated and stable magnetic circuit. The mover 303B is made of T2 copper material, whose high conductivity is conducive to generating a strong eddy current effect. The damper 303 is symmetrically installed in a circumferential array in the annular space between the Spar single-column platform 202 and the central cylinder 203 by eight sets of M30 grade 10.9 high-strength bolts, with an installation torque of 900 N·m, and a double-nut anti-loosening measure is adopted.

[0058] In this embodiment, the damper 303 has a rated working air gap of 3±0.5mm and a maximum damping force of ±800kN. The coil 404 uses H-class insulated high-temperature resistant electromagnetic wire, allowing it to operate continuously below 180℃. When the platform undergoes relative motion, the mover 303B moves with the Spar single-column platform 202, cutting the constant magnetic field generated by the stator 303A, generating eddy currents in the mover 303B. These eddy currents are then acted upon by the original magnetic field, generating a Lorentz force opposite to the direction of motion, thus forming a damping effect and converting mechanical kinetic energy into heat energy dissipation. This process requires no physical contact, avoiding friction and wear, and the damping force is proportional to the relative velocity, effectively suppressing the multi-degree-of-freedom vibration of the platform. The damper 303 in this embodiment features fast response, long life, and adjustable damping force, significantly improving the platform's motion stability and safety under harsh sea conditions.

[0059] Semi-submersible platform 201, due to its large displacement volume and shallow draft, mainly moves with the waves, and its heave response is significant, which can be regarded as a base that rises and falls with the waves; Spar single-column platform 202, due to its deep draft and large mass, has extremely large inertia and a very long natural heave period, which is far beyond the period range of common waves. It has a natural inertia in the heave motion of high-frequency waves.

[0060] When the waves cause the Semi-submersible platform 201 to sway significantly, the damping buffer device 302 connecting the Semi-submersible platform 201 and the Spar single-column platform 202 starts to work, filtering and absorbing most of the kinetic energy transmitted from the Semi-submersible platform 201 through elastic deformation and damping energy dissipation.

[0061] The control device 306 can determine whether the damping buffer device 302 participates in the work through finite element model and control algorithm analysis, and determine the number of damping buffer devices 302 that are activated and the actual damping force F and other working parameters.

[0062] like Figure 9 , Figure 10 As shown, the energy supply system 4 includes a wave energy generation device 401 and an energy storage and power supply device 402. The wave energy generation device 401 includes an electromagnetic induction power generation device 403. The electromagnetic induction power generation device 403 includes a coil 404 and a permanent magnet 405. In this embodiment, the coil 404 is 13m high and is fixed around the outer periphery of the Spar single-column platform 202 to form a closed induction circuit. The permanent magnet 405 is 21m high and is symmetrically fixed to the inner wall of the central cylinder 203 by welding. It is used to provide a high-intensity and stable background magnetic field, ensuring the stability and strength of the magnetic field. The energy storage and power supply device 402 is set on the rigid partition 407.

[0063] The coil 404 is connected to the energy storage and power supply device 402 via the wire 406, and the energy storage and power supply device 402 is connected to the motion control system 3 via the wire 406.

[0064] The semi-submersible platform 201 and the Spar monocoque platform 202 decouple in the heave direction, resulting in vertical relative motion. This motion causes continuous relative displacement between the coil 404 fixed to the Spar monocoque platform 202 and the permanent magnet 405 fixed to the central cylinder 203. The coil 404 thus effectively cuts magnetic field lines, generating an induced electromotive force based on Faraday's law of electromagnetic induction. The generated electrical energy is transmitted via wire 406 to the energy storage and power supply device 402 for storage and subsequent use.

[0065] like Figure 11 As shown in the figure, the operation flow of the autonomously powered Semi-Spar offshore wind turbine structure and its motion control method described in this embodiment is as follows:

[0066] S1. The monitoring device 305 monitors the speed V1 of the Semi-submersible platform 201 and the speed V2 of the Spar single-column platform 202 at both ends of the damper 303, and then obtains the relative speed U=V1-V2 at both ends of the damper 303.

[0067] S2. Control device 306 calculates the product of the two velocity signals, V1×U, and determines whether the result is greater than 0. This judgment condition is essentially checking whether the damper 303 is working, that is, whether the direction of the damping force is consistent with the direction of the desired control force. If so, the damper 303 can effectively dissipate the kinetic energy of the object, and then jumps to S3; if not, the damper 303 is not working, and then jumps to S1.

[0068] S3. Calculate the desired control force:

[0069] T = -C × V1;

[0070] Where C is the desired control damping coefficient, and the negative sign indicates that the direction of the desired control force is opposite to the direction of the velocity V1 of the Semi-submersible platform 201.

[0071] S4. Damper 303 starts working. Determine the operating parameters of damper 303, including the number of starts, actual damping coefficient, and actual damping force F:

[0072] F = μ × U;

[0073] Where μ is the damping coefficient;

[0074] S5. Monitoring device 305 continues to collect data to determine whether the platform movement has returned to normal working state. If not, it jumps to S3; if yes, it ends.

[0075] Therefore, this invention adopts the above-mentioned self-powered Semi-Spar offshore wind turbine structure and its motion control device and method. Through the cooperation of the Semi semi-submersible platform and the Spar single-column platform in the separated platform, plus the motion control system, the motion suppression of the offshore wind turbine system is achieved, reducing dynamic instability and fatigue damage, and improving structural safety and reliability. Through the wave energy power generation device and energy storage and power supply device, wave energy is converted into electrical energy, realizing the power supply when the wind turbine is stopped, avoiding energy waste.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A self-powered Semi-Spar offshore wind turbine structure, characterized by: The system includes a detachable platform, which comprises a Semi-submersible platform and a Spar monocoque platform. The Semi-submersible platform includes a float and a center tube, with the center tube located in the center of the Semi-submersible platform. A superstructure is provided above the Spar monocoque platform, which is located at the center of the center tube. A motion control system and a power supply system are provided on the detachable platform. The motion control system includes a limit device, a damping buffer device, a monitoring device, and a control device; The limiting device is installed at both ends of the Spar single-column platform, and the limiting device is equipped with a mechanical stop device. The damping buffer device is installed between the central cylinder and the Spar single-column platform. The monitoring device is installed at both ends of the damping buffer device. The control device is connected to the monitoring device, and the damping buffer device is connected to the control device. The damping buffer device is one or more of buffer springs and dampers. A rigid partition is provided at the upper end of the Spar single-column platform. The control device is located on the rigid partition. The energy supply system includes a wave energy power generation device and an energy storage and power supply device, wherein the wave energy power generation device includes an electromagnetic induction power generation device. The electromagnetic induction power generation device includes a coil and a permanent magnet. The coil is disposed on the outer surface of the Spar single-column platform, the permanent magnet is disposed on the inner surface of the central cylinder, and the energy storage and power supply device is disposed on the rigid partition.

2. The self-powered Semi-Spar offshore wind turbine structure according to claim 1, characterized in that: The superstructure includes a tower, which is located above the Spar single-column platform. A nacelle is located on the top of the tower, and a hub is located in the nacelle. Blades are located on the hub.

3. The self-powered Semi-Spar offshore wind turbine structure according to claim 1, characterized in that: The damper comprises a stator and a mover.

4. The self-powered Semi-Spar offshore wind turbine structure according to claim 1, characterized in that: The coil is connected to the energy storage and power supply device via a wire, and the energy storage and power supply device is connected to the control device via a wire.

5. The motion control method for the self-powered Semi-Spar offshore wind turbine structure according to any one of claims 1-4, characterized in that, Includes the following steps: S1. The monitoring device monitors the velocities V1 of the semi-submersible platform and V2 of the single-column platform at both ends of the damper, thereby obtaining the relative velocities at both ends of the damper: U = V1 - V2; S2. The control device calculates the product of the two speed signals: V1×U; And determine whether the result is greater than 0. If it is, the direction of the damping force is consistent with the direction of the expected control force, the damper works, and the kinetic energy of the object is effectively dissipated. Then jump to S3. If not, the damper does not work. Then jump to S1. S3. Calculate the desired control force: T = -C × V1; Where C is the desired control damping coefficient, and the negative sign indicates that the direction of the desired control force is opposite to the direction of the velocity V1 of the Semi-submersible platform. S4. The damper starts working. Determine the damper's operating parameters, including the number of units started, the actual damping coefficient, and the actual damping force. The actual damping force F is: F = μ × U; Where μ is the damping coefficient; S5. The monitoring device continues to collect data and determines whether the platform movement has returned to normal working state. If not, it jumps to S3; if yes, it ends.

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