Yaw control method for floating wind turbine based on active posture regulation and hydrodynamic coupling

Abstract

This invention belongs to the field of offshore wind power technology and relates to a yaw control method for floating wind turbines based on active attitude control and hydrodynamic coupling. It includes: acquiring the target yaw angle and actual yaw angle of the floating wind turbine and determining the yaw deviation; determining the target attitude angle of the floating wind turbine based on its actual attitude angle, water flow velocity, and wind load; adjusting the ballast distribution inside the floating wind turbine to achieve the target attitude angle; and generating a hydrodynamic yaw moment to drive the floating wind turbine's yaw motion by utilizing the hydrodynamic coupling effect generated by the interaction between the floating wind turbine and the surrounding water flow at the target attitude angle. This invention replaces traditional mechanical transmission or propellers with hydrodynamic power for yaw drive, eliminating parasitic energy consumption and mechanical wear; and actively controls the floating wind turbine's attitude through the ballast system to stimulate the hydrodynamic coupling effect, thereby achieving improved wind accuracy and reduced structural fatigue load in a low-cost and highly reliable manner.

Description

Technical Field

[0001] This invention belongs to the field of offshore wind power technology and relates to a yaw control method for floating wind turbines based on active attitude regulation and hydrodynamic coupling. Background Technology

[0002] Single-point moored (SPM) floating wind turbines are considered an important technological approach for deep-sea wind power development due to their simple mooring system and ability to passively engage winds using the wind vane effect. However, this passive wind-engaging mechanism has inherent limitations in actual marine environments, making it difficult to guarantee efficient and reliable power generation.

[0003] On the one hand, as rigid bodies with large mass and inertia, floating wind turbines are subject to the combined effects of multiple environmental loads such as wind, waves, and currents during rotation. This results in slow passive rotation response, making it impossible to accurately track rapidly changing wind directions. Continuous yaw errors not only significantly reduce wind energy capture efficiency but also induce asymmetric aerodynamic fatigue loads on critical components such as blades and towers, shortening the unit's service life. On the other hand, under low wind speed conditions, the yaw moment generated by the wind may be insufficient to overcome the hydrodynamic damping and mooring constraints faced by the floating wind turbine's rotation, causing it to become stuck at an incorrect yaw angle and lose its ability to follow the wind. Furthermore, when the force of the water flow is dominant, the yaw attitude of the floating wind turbine is often "locked" by the direction of the water flow, making it impossible to adjust according to the wind direction and causing power generation interruptions.

[0004] To overcome the aforementioned shortcomings, existing technologies have proposed active yaw solutions, but all of them have fundamental problems that are difficult to avoid. Among them, when using the nacelle yaw device of onshore wind turbines on floating wind turbines, the nacelle yaw system needs to use extremely high torque and power to counteract or follow the movement of the floating wind turbine due to the low-frequency rotational motion of the single-point moored floating wind turbine itself. This results in components such as yaw bearings and gearboxes being subjected to extreme impact loads and severe wear, making it the part with the highest system failure rate and the most expensive operation and maintenance cost.

[0005] Another option is to install a thruster on the underwater part of the floating wind turbine to directly drive its rotation. However, this option significantly increases capital expenditure due to the high cost of the thruster system itself, power supply and control equipment. Underwater rotating components also face risks such as marine organism attachment, corrosion and collisions, resulting in poor reliability and maintainability. Maintenance operations require special vessels and diving operations, leading to high operation and maintenance costs. At the same time, the thruster generates significant parasitic energy consumption to continuously overcome environmental loads, further reducing the overall economic benefits of the wind farm. Summary of the Invention

[0006] To address the problems in the prior art, this invention provides a yaw control method for floating wind turbines based on active attitude control and hydrodynamic coupling. This method uses hydrodynamics to replace traditional mechanical transmission or propellers for yaw drive, eliminating parasitic energy consumption and mechanical wear. By actively controlling the attitude of the floating wind turbine through the ballast system to stimulate the hydrodynamic coupling effect, it achieves improved wind accuracy and reduced structural fatigue load in a low-cost and highly reliable manner.

[0007] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a yaw control method for floating wind turbines based on active attitude regulation and hydrodynamic coupling, comprising the following steps: The target yaw angle and the actual yaw angle of the floating wind turbine are obtained, and the yaw deviation is determined based on the target yaw angle and the actual yaw angle. The actual attitude angle of the floating wind turbine in the non-yaw direction, the water flow velocity in the water area where the floating wind turbine is located, and the wind load acting on the floating wind turbine are obtained. The target attitude angle of the floating wind turbine in the non-yaw direction is determined based on the yaw deviation, the actual attitude angle, the water flow velocity, and the wind load. Adjust the ballast distribution inside the floating wind turbine to make the floating wind turbine reach the target attitude angle; utilize the hydrodynamic coupling effect generated by the interaction between the floating wind turbine and the surrounding water flow at the target attitude angle to generate a hydrodynamic yaw moment to drive the floating wind turbine to yaw.

[0008] Preferably, obtaining the target yaw angle of the floating wind turbine includes: Obtain wind vector information at a preset distance in front of the floating wind turbine; The target yaw angle of the floating wind turbine is determined based on the wind vector information.

[0009] Preferably, obtaining the actual yaw angle of the floating wind turbine includes: Obtain the attitude and motion information of the floating wind turbine; Based on the attitude motion information, the actual yaw angle of the floating wind turbine is determined.

[0010] Preferably, obtaining the actual attitude angle of the floating wind turbine in the non-yaw direction includes: Based on the attitude motion information, the roll angle component in the roll direction and the pitch angle component in the pitch direction of the floating wind turbine are determined. The roll and pitch components are determined as the actual attitude angles of the floating wind turbine in the non-yaw direction.

[0011] Preferably, determining the target attitude angle of the floating wind turbine in the non-yaw direction based on the yaw deviation, the actual attitude angle, the water flow velocity, and the wind load includes: Construct a mapping relationship between the attitude angle of the floating wind turbine, the water flow velocity, the wind load, and the yaw moment experienced by the floating wind turbine; Based on the yaw deviation, determine the target yaw moment required to correct the yaw deviation; Using the target yaw moment as the control target and the safety constraints of the floating wind turbine during operation as the solution constraints, based on the actual attitude angle, the water flow velocity, and the wind load, and combined with the preset mapping relationship, a target attitude angle sequence that satisfies the safety constraints and makes the deviation between the actual yaw moment and the target yaw moment optimal is obtained. The first value in the target attitude angle sequence is taken as the target attitude angle of the current control cycle.

[0012] Preferably, the safety constraints include: The maximum permissible tilt angle constraint of the floating wind turbine in the yaw direction; The maximum permissible tilt angle constraint of the floating wind turbine in the pitch direction; The maximum structural load constraint allowed during the operation of the floating wind turbine; The maximum water diversion rate constraint and total capacity constraint of the ballast system for adjusting the ballast distribution inside the floating wind turbine.

[0013] Preferably, the mapping relationship Characterized by a pre-defined hydrodynamic coupling effect model, the expression of the hydrodynamic coupling effect model is as follows:

[0014] In the formula, The yaw moment experienced by the floating wind turbine; The yaw angle component of the floating wind turbine; Let be the pitch angle component of the floating wind turbine; The vector representing the water flow velocity; The vector of the wind load.

[0015] Preferably, the method for constructing the hydrodynamic coupling effect model includes: By computational fluid dynamics simulation, a database of the yaw moment response of the floating wind turbine under different attitude angles, different water flow velocities and different wind load combinations is established, and an initial hydrodynamic coupling effect model is obtained by fitting the database. During the operation of the floating wind turbine, the initial hydrodynamic coupling effect model is adaptively corrected by using online system identification technology and real-time collected data on attitude angle, water flow velocity, wind load, and actual yaw moment, so as to update the mapping relationship.

[0016] Preferably, adjusting the ballast distribution inside the floating wind turbine to achieve the target attitude angle includes: S1. Determine the attitude angle deviation based on the target attitude angle and the actual attitude angle; S2. Based on the attitude angle deviation, adjust the ballast water distribution among the multiple ballast water tanks inside the floating wind turbine to change the attitude of the floating wind turbine in the non-yaw direction. S3. Repeat S1~S2 until the deviation between the actual attitude angle of the floating wind turbine in the non-yaw direction and the target attitude angle meets the preset accuracy requirement.

[0017] Preferably, the step of utilizing the hydrodynamic coupling effect generated by the interaction between the floating wind turbine and the surrounding water flow at the target attitude angle to generate a hydrodynamic yaw moment for driving the floating wind turbine to yaw motion includes: When the floating wind turbine maintains an inclined attitude at the target attitude angle, the underwater part of the floating wind turbine interacts asymmetrically with the relative water flow, forming an asymmetrical pressure distribution and viscous force distribution on the wet surface of the underwater part. The asymmetrical pressure distribution and viscous force distribution, after integration, form the hydrodynamic yaw moment, which drives the floating wind turbine to yaw.

[0018] Compared with the prior art, the present invention has the following beneficial effects: By obtaining the target yaw angle and the actual yaw angle, the yaw deviation is determined, and the actual attitude angle, water flow velocity, and wind load in the non-yaw direction are simultaneously obtained, achieving accurate perception of yaw error and environmental conditions. Based on the above multi-source information, the target attitude angle in the non-yaw direction is determined, making yaw control directly related to the attitude control of the floating wind turbine. Then, by adjusting the ballast distribution inside the floating wind turbine, the floating wind turbine reaches the target attitude angle. The yaw torque is generated by the hydrodynamic coupling effect generated by the interaction between the floating wind turbine and the water flow, thereby changing the yaw drive from the traditional mechanical transmission or propeller method to a contactless drive based on water flow energy. While significantly reducing parasitic energy consumption and mechanical wear, high-precision and low-cost yaw control is achieved with a simple and reliable ballast control structure. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram illustrating the yaw principle of a floating wind turbine. Figure 3 This is a schematic diagram of a ballast water tank.

[0021] Among them: 1. Floating wind turbine; 2. Ballast water tank. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply refers to its direction relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0027] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0028] The present invention will now be described in further detail with reference to the accompanying drawings: This invention provides a yaw control method for floating wind turbines based on active attitude regulation and hydrodynamic coupling, such as... Figure 1 As shown, it includes the following steps: S1. Obtain the target yaw angle and the actual yaw angle of the floating wind turbine 1, and determine the yaw deviation based on the target yaw angle and the actual yaw angle.

[0029] The process of obtaining the target yaw angle of the floating wind turbine 1 includes: Obtain wind vector information at a preset distance in front of the floating wind turbine 1; Based on the wind vector information, the target yaw angle of the floating wind turbine 1 is determined.

[0030] Specifically, the target yaw angle is determined by using a feedforward wind-measuring lidar deployed on the floating wind turbine 1 to detect wind vector information at a preset distance (e.g., 2 to 4 times the rotor diameter) in front of the wind turbine in real time, including wind speed, wind direction and turbulence intensity, and to calculate the optimal windward angle as the target yaw angle based on the incoming wind vector information.

[0031] The process of obtaining the actual yaw angle of the floating wind turbine 1 includes: Obtain the attitude and motion information of the floating wind turbine 1; Based on the attitude motion information, the actual yaw angle of the floating wind turbine 1 is determined.

[0032] Specifically, the actual yaw angle is calculated in real time by combining the high-precision inertial measurement unit installed on the floating wind turbine 1 with the global navigation satellite system to obtain the complete six-degree-of-freedom attitude motion information of the floating wind turbine 1, and the current yaw angle is extracted as the feedback quantity.

[0033] This invention accurately calculates the yaw deviation by comparing the target yaw angle predicted based on feedforward with the actual yaw angle based on real-time feedback. On the one hand, the feedforward measurement using lidar overcomes the inherent lag in response of traditional passive wind-fighting methods, enabling the system to pre-adjust before wind conditions change. On the other hand, by using a high-precision integrated navigation system to monitor the movement of the floating wind turbine 1 in real time, the interference of environmental loads such as waves and water flow on the accuracy of yaw angle measurement is eliminated, providing reliable state feedback for subsequent precise control.

[0034] S2. Obtain the actual attitude angle of the floating wind turbine 1 in the non-yaw direction, the water flow velocity of the water area where the floating wind turbine 1 is located, and the wind load acting on the floating wind turbine 1.

[0035] The step of obtaining the actual attitude angle of the floating wind turbine 1 in the non-yaw direction includes: Based on the attitude motion information, the roll angle component of the floating wind turbine 1 in the roll direction and the pitch angle component in the pitch direction are determined. The roll and pitch components are determined as the actual attitude angles of the floating wind turbine 1 in the non-yaw direction.

[0036] Specifically, the actual attitude angle of the floating wind turbine 1 in the non-yaw direction is obtained by extracting the roll and pitch components from the six-degree-of-freedom attitude motion information and determining them together as the actual attitude angle in the non-yaw direction, thereby fully characterizing the current spatial tilt state of the floating wind turbine 1.

[0037] Meanwhile, the water flow velocity in the water area where the floating wind turbine 1 is located is measured in real time using an acoustic Doppler current profiler deployed in the underwater part of the floating wind turbine 1. This measurement includes the magnitude and direction of the flow velocity vector from the water surface to a certain depth, accurately describing the relative motion between the floating wind turbine 1 and the surrounding water. The wind load acting on the floating wind turbine 1 is estimated in real time based on the wind profile information measured by the aforementioned wind-measuring lidar, combined with the aerodynamic characteristics of the floating wind turbine 1, such as its thrust coefficient curve. This estimation also includes the equivalent wind thrust borne by the impeller surface and the wind load moment acting on the floating wind turbine 1.

[0038] S3. Determine the target attitude angle of the floating wind turbine 1 in the non-yaw direction based on the yaw deviation, the actual attitude angle, the water flow velocity, and the wind load.

[0039] The step of determining the target attitude angle of the floating wind turbine 1 in the non-yaw direction based on the yaw deviation, the actual attitude angle, the water flow velocity, and the wind load includes: The attitude angle of the floating wind turbine 1, the water flow velocity, the wind load, and the yaw moment M experienced by the floating wind turbine 1 are determined. Z The mapping relationship between them; Based on the yaw deviation, determine the target yaw moment required to correct the yaw deviation; Using the target yaw moment as the control target and the safety constraints of the floating wind turbine 1 during operation as the solution constraints, based on the actual attitude angle, the water flow velocity, and the wind load, and combined with the preset mapping relationship, a target attitude angle sequence that satisfies the safety constraints and makes the deviation between the actual yaw moment and the target yaw moment optimal is obtained. The first value in the target attitude angle sequence is taken as the target attitude angle of the current control cycle.

[0040] This method constructs a mapping relationship between the attitude angles (including roll and pitch angles), water flow velocity vector, wind load vector, and yaw moment of the floating wind turbine 1 using a pre-defined hydrodynamic coupling effect model. This mapping relationship quantitatively describes the yaw moment response that the system can generate under given attitude and environmental conditions. Subsequently, based on the yaw deviation and combined with the desired dynamic response characteristics (such as no overshoot and response time), the target yaw moment required to correct the deviation is determined. On this basis, the target yaw moment is used as the optimization objective, and the safety constraints of the floating wind turbine 1 during operation are used as the solution constraints. Using the current actual attitude angle, measured water flow velocity, and real-time estimated wind load as the initial state, the mapping relationship is used as the prediction model to perform rolling prediction of the system's future response within a preset prediction time domain. By solving the optimization problem, a target attitude angle control sequence is obtained that satisfies all constraints and optimizes the cumulative deviation between the actual yaw moment and the target yaw moment within the prediction time domain. Finally, the first value in the control sequence (i.e., the command value of the current control cycle) is output as the target attitude angle to the actuator. The above process is repeated in the next control cycle to achieve rolling optimization and feedback correction.

[0041] For example, the security constraints include: The maximum allowable tilt angle constraint of the floating wind turbine 1 in the yaw direction; The maximum allowable tilt angle constraint of the floating wind turbine 1 in the pitch direction; The maximum structural load constraint allowed during the operation of the floating wind turbine 1; The maximum water diversion rate constraint and total capacity constraint of the ballast system for adjusting the ballast distribution inside the floating blower 1.

[0042] The maximum allowable tilt angle constraints in the roll and pitch directions are limit thresholds set based on the complete stability check results of the floating wind turbine 1. These thresholds ensure that the floating wind turbine 1 does not lose stability or overturn due to excessive tilting under any operating condition. The maximum structural load constraint covers the allowable design loads of the blades, tower, mooring cables, and the main structure of the floating wind turbine 1 under extreme and fatigue conditions, to prevent structural damage caused by additional loads during yaw control.

[0043] like Figures 2-3 As shown, the ballast system includes multiple ballast water tanks, symmetrically or evenly distributed in different compartments of the floating wind turbine 1 (for example, distributed in four quadrants at the four corners of the floating wind turbine 1, or distributed in a hexagonal layout around the floating wind turbine 1). Each ballast water tank is connected to the main pipeline network of the system through independent inlet / outlet branch pipelines. Each branch pipeline is equipped with an electrically controlled intelligent valve to independently control the on / off state and flow rate of the corresponding water tank. Several water pumps with bidirectional pumping capability are connected in parallel to the main pipeline network. The inlet and outlet of the water pumps are switched through pipeline reversing valve groups. When the system receives an attitude control command, the controller calculates the target water volume change for each ballast tank based on the target attitude angle. Then, by controlling the opening and closing combinations of intelligent valves, it selects the ballast tank pairs to participate in the adjustment and starts the corresponding pumps in the corresponding directions. Ballast water is extracted from one or more tanks and pumped through the main pipeline network to the target tank, thereby dynamically changing the center of gravity position of the floating blower 1. This generates a precise and controllable restoring torque in the roll and pitch directions, driving the floating blower 1 to rotate around its pivot point and smoothly approach the target attitude angle. The maximum water adjustment rate constraint and total capacity constraint of the ballast system correspond to the pump delivery capacity limit and the adjustable water volume limit of each ballast tank, respectively, ensuring that the command sequence obtained from the optimization solution can be accurately reproduced at the actual execution level.

[0044] For example, the mapping relationship Characterized by a pre-defined hydrodynamic coupling effect model, the expression of the hydrodynamic coupling effect model is as follows:

[0045] In the formula, The yaw moment is the force exerted on the floating wind turbine 1. Let be the roll angle component of the floating fan 1; Let be the pitch angle component of the floating fan 1; The vector representing the water flow velocity; The vector of the wind load.

[0046] When the floating wind turbine 1 maintains a specific combination of roll and pitch attitude under active mass control, an asymmetric flow effect occurs between its underwater portion and the relative water flow. The pressure and viscous force distributed on the wetted surface, after integration, form a yaw moment acting on the entire turbine. The magnitude and direction of this moment are jointly determined by the attitude angle, water flow conditions, and wind load. The hydrodynamic coupling effect model is a nonlinear function that is pre-established through computational fluid dynamics simulation and continuously corrected through online system identification. This is used to describe this complex fluid-structure interaction process.

[0047] For example, the hydrodynamic coupling effect model is constructed based on the principle of flow moment in fluid dynamics, and its expression is:

[0048] In the formula, Where A is the density of seawater; A is the projected characteristic area of ​​the underwater part of the floating wind turbine 1 on the horizontal plane; The characteristic length of the underwater portion of the floating wind turbine 1; The angle of the water flow direction; The wind load direction angle; , , and These are the dimensionless hydrodynamic coefficients determined through computational fluid dynamics simulation fitting.

[0049] In the expression, the first term characterizes the hydrodynamic yaw moment dominated by the platform's tilt attitude. The linear attitude angle term and the coupling term together describe the influence of platform tilt on the flow asymmetry, while the cosine term reflects the modulation effect of the relative angle between the water flow direction and the wind direction on the yaw moment direction. The second term characterizes the aerodynamic yaw moment component generated by the wind load directly acting on the above-water portion, reflecting the coupling characteristics of the yaw moment under the combined action of wind and flow. The hydrodynamic coupling effect model pre-establishes initial coefficients through computational fluid dynamics simulation and continuously corrects the coefficients during the operation of the floating wind turbine 1 using online system identification technology. , , and To update the mapping relationship.

[0050] For example, the method for constructing the hydrodynamic coupling effect model includes: By computational fluid dynamics simulation, a database of the yaw moment response of the floating wind turbine 1 under different attitude angles, different water flow velocities and different wind load combinations is established, and an initial hydrodynamic coupling effect model is obtained by fitting the database. During the operation of the floating wind turbine 1, the initial hydrodynamic coupling effect model is adaptively corrected by using online system identification technology and real-time collected data on attitude angle, water flow velocity, wind load, and actual yaw moment, so as to update the mapping relationship.

[0051] The method for constructing the hydrodynamic coupling effect model used in this invention employs a two-stage approach combining offline simulation and online identification. Specifically: In the offline phase, computational fluid dynamics simulation is used to systematically simulate the geometric model of the floating wind turbine 1 within a preset parameter space. This includes: discretizing the values ​​of the roll and pitch angles within their respective ranges at preset step sizes; setting several sets of working points within typical working ranges of the water velocity vector (including velocity magnitude and direction of flow) and wind load vector (including wind speed magnitude and direction); combining the attitude angles, water velocity, and wind load with all factors to form a simulation matrix covering all design working conditions; calculating the yaw moment response of the floating wind turbine 1 at each working point to construct a complete yaw moment response database; and then, based on this database, establishing an initial hydrodynamic coupling effect model using an appropriate fitting method (such as polynomial fitting) to characterize the nonlinear mapping relationship between the yaw moment and the roll, pitch, water velocity vector, and wind load vector.

[0052] During the online phase, during the actual operation of the floating wind turbine 1, the actual attitude angle, measured water flow velocity, real-time estimated wind load, and actual yaw motion response indirectly observed by sensors such as the inertial measurement unit are continuously collected. Using online system identification techniques such as recursive least squares and Kalman filtering, the real-time data is input and the parameters of the initial model are adaptively corrected. This enables the model to dynamically track the drift of hydrodynamic characteristics caused by long-term changes such as marine organism attachment, structural aging, or aquatic organism deposition, thereby continuously updating the mapping relationship to maintain the model accuracy.

[0053] S4. Adjust the ballast distribution inside the floating wind turbine 1 so that the floating wind turbine 1 reaches the target attitude angle; utilize the hydrodynamic coupling effect generated by the interaction between the floating wind turbine 1 and the surrounding water flow at the target attitude angle to generate a hydrodynamic yaw moment for driving the floating wind turbine 1 to yaw.

[0054] For example, adjusting the ballast distribution inside the floating wind turbine 1 to achieve the target attitude angle includes: S1. Determine the attitude angle deviation based on the target attitude angle and the actual attitude angle; S2. Based on the attitude angle deviation, adjust the ballast water distribution among the multiple ballast water tanks inside the floating wind turbine 1 to change the attitude of the floating wind turbine 1 in the non-yaw direction. S3. Repeat S1~S2 until the deviation between the actual attitude angle of the floating wind turbine 1 in the non-yaw direction and the target attitude angle meets the preset accuracy requirements.

[0055] Specifically, firstly, based on the target attitude angle predicted by the model and the actual attitude angle fed back in real time by the inertial measurement unit, the attitude angle deviations in the roll and pitch directions are calculated. Then, using these attitude angle deviations as control inputs, a preset proportional-integral-derivative control algorithm is used to calculate the target water transfer volume and rate between each ballast tank. Subsequently, by controlling the opening and closing combinations of the intelligent valve network and the operating direction and speed of the bidirectional pumps, ballast water is precisely pumped from one or more source tanks to the target tank according to the calculated flow rate, dynamically changing the center of gravity distribution of the floating blower 1, thereby generating a restoring torque to drive the floating blower 1 towards the target attitude angle. During this process, the system continuously samples the actual attitude angle at a high frequency (e.g., 50Hz) and compares it with the target attitude angle, forming a negative feedback closed loop. The above steps S1~S2 are repeated until the deviations between the actual attitude angle and the target attitude angle in both the roll and pitch directions are consistently stable within a preset accuracy threshold, at which point attitude tracking is considered complete.

[0056] For example, the step of utilizing the hydrodynamic coupling effect generated by the interaction between the floating wind turbine 1 and the surrounding water flow at the target attitude angle to generate a hydrodynamic yaw moment for driving the floating wind turbine 1 to yaw motion includes: When the floating wind turbine 1 maintains an inclined attitude at the target attitude angle, the underwater part of the floating wind turbine 1 interacts asymmetrically with the relative water flow, forming an asymmetrical pressure distribution and viscous force distribution on the wet surface of the underwater part. The asymmetrical pressure distribution and viscous force distribution are integrated to form the hydrodynamic yaw moment, which is used to drive the floating wind turbine 1 to yaw.

[0057] Specifically, when the ballast system adjusts the floating wind turbine 1 to the target attitude angle and maintains this tilted attitude, the geometric profile of the underwater part of the floating wind turbine 1 (such as the optimized deep V-shaped cross-section, asymmetric bilge keel, fixed underwater blades or guide fins, etc.) and the relative water flow form asymmetric flow conditions: on the upstream and downstream sides, and on the tilted sinking and lifting sides, the streamlines of the water flow undergo different degrees of deflection and separation, resulting in significant differences in the relative velocity and angle of attack of the water flow in different areas of the wetted surface. According to Bernoulli's principle and viscosity in fluid mechanics... According to the theory of fluid dynamics, this difference is directly transformed into an asymmetric pressure field (pressure drag component) and an asymmetric shear stress field (friction drag component) distributed along the wet surface. The resultant force and resultant moment of the two depend on the tilt direction and tilt amplitude of the floating fan 1. The above-mentioned asymmetric pressure distribution and viscous force distribution are integrated on the entire wet surface to form a net yaw moment. The magnitude and direction of this moment can be continuously and precisely controlled by adjusting the combination of the roll and pitch angles of the floating fan 1, thereby driving the floating fan 1 to rotate as a whole towards the target yaw angle.

[0058] The yaw moment is converted from water flow energy. The system consumes very little energy only when maintaining attitude (to overcome the static power consumption of the ballast system). No additional continuous power input is required, which fundamentally eliminates the parasitic energy consumption in traditional active yaw schemes and significantly improves the net power generation efficiency and economy of wind farms. In addition, the generated yaw control moment is a smooth and continuous hydrodynamic force, rather than a mechanical or propeller-driven pulse impact force, which effectively reduces the fatigue load on the floating wind turbine structure and mooring system and helps to extend the system life.

[0059] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling, characterized in that, Includes the following steps: Obtain the target yaw angle and the actual yaw angle of the floating wind turbine (1), and determine the yaw deviation based on the target yaw angle and the actual yaw angle; The actual attitude angle of the floating wind turbine (1) in the non-yaw direction, the water flow velocity of the water area where the floating wind turbine (1) is located, and the wind load acting on the floating wind turbine (1) are obtained. Based on the yaw deviation, the actual attitude angle, the water flow velocity, and the wind load, the target attitude angle of the floating wind turbine (1) in the non-yaw direction is determined; Adjust the ballast distribution inside the floating wind turbine (1) so that the floating wind turbine (1) reaches the target attitude angle; use the hydrodynamic coupling effect generated by the interaction between the floating wind turbine (1) and the surrounding water flow at the target attitude angle to generate a hydrodynamic yaw torque for driving the floating wind turbine (1) to yaw.

2. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 1, characterized in that, The process of obtaining the target yaw angle of the floating wind turbine (1) includes: Obtain wind vector information at a preset distance in front of the floating wind turbine (1); Based on the wind vector information, the target yaw angle of the floating wind turbine (1) is determined.

3. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 1, characterized in that, The process of obtaining the actual yaw angle of the floating wind turbine (1) includes: Obtain the attitude and motion information of the floating wind turbine (1); Based on the attitude motion information, the actual yaw angle of the floating wind turbine (1) is determined.

4. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 3, characterized in that, The process of obtaining the actual attitude angle of the floating wind turbine (1) in the non-yaw direction includes: Based on the attitude motion information, determine the roll angle component in the roll direction and the pitch angle component in the pitch direction of the floating wind turbine (1). The roll and pitch components are determined as the actual attitude angles of the floating wind turbine (1) in the non-yaw direction.

5. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 1, characterized in that, The step of determining the target attitude angle of the floating wind turbine (1) in the non-yaw direction based on the yaw deviation, the actual attitude angle, the water flow velocity, and the wind load includes: Construct a mapping relationship between the attitude angle of the floating wind turbine (1), the water flow velocity, the wind load and the yaw moment of the floating wind turbine (1); Based on the yaw deviation, determine the target yaw moment required to correct the yaw deviation; Using the target yaw moment as the control target and the safety constraints of the floating wind turbine (1) during operation as the solution constraints, based on the actual attitude angle, the water flow velocity and the wind load, and combined with the preset mapping relationship, the target attitude angle sequence that satisfies the safety constraints and makes the deviation between the actual yaw moment and the target yaw moment reach the optimal is solved. The first value in the target attitude angle sequence is used as the target attitude angle for the current control cycle.

6. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 5, characterized in that, The security constraints include: The maximum permissible tilt angle constraint of the floating wind turbine (1) in the yaw direction; The maximum permissible tilt angle constraint of the floating wind turbine (1) in the pitch direction; The maximum structural load constraint allowed during the operation of the floating wind turbine (1); Adjust the maximum water diversion rate constraint and total capacity constraint of the ballast system for the internal ballast distribution of the floating fan (1).

7. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 5, characterized in that, The mapping relationship Characterized by a pre-defined hydrodynamic coupling effect model, the expression of the hydrodynamic coupling effect model is as follows: In the formula, The yaw moment experienced by the floating wind turbine (1); The yaw angle component of the floating fan (1); The pitch angle component of the floating fan (1); The vector representing the water flow velocity; The vector of the wind load.

8. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 7, characterized in that, The method for constructing the hydrodynamic coupling effect model includes: By computational fluid dynamics simulation, a database of the yaw moment response of the floating wind turbine (1) under different attitude angles, different water flow velocities and different wind load combinations is established, and an initial hydrodynamic coupling effect model is obtained by fitting the database. During the operation of the floating wind turbine (1), the initial hydrodynamic coupling effect model is adaptively corrected by using online system identification technology and real-time collected attitude angle, water flow velocity, wind load and actual yaw moment data, so as to update the mapping relationship.

9. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 1, characterized in that, Adjusting the ballast distribution inside the floating wind turbine (1) to achieve the target attitude angle includes: S1. Determine the attitude angle deviation based on the target attitude angle and the actual attitude angle; S2. Based on the attitude angle deviation, adjust the ballast water distribution between multiple ballast water tanks inside the floating wind turbine (1) to change the attitude of the floating wind turbine (1) in the non-yaw direction. S3. Repeat S1~S2 until the deviation between the actual attitude angle of the floating wind turbine (1) in the non-yaw direction and the target attitude angle meets the preset accuracy requirements.

10. The yaw control method for a floating wind turbine based on active attitude regulation and hydrodynamic coupling according to claim 1, characterized in that, The process of generating a hydrodynamic yaw moment to drive the floating wind turbine (1) to yaw motion by utilizing the hydrodynamic coupling effect generated by the interaction between the floating wind turbine (1) and the surrounding water flow at the target attitude angle includes: When the floating wind turbine (1) maintains an inclined attitude at the target attitude angle, the underwater part of the floating wind turbine (1) interacts asymmetrically with the relative water flow, forming an asymmetrical pressure distribution and viscous force distribution on the wet surface of the underwater part. The asymmetrical pressure distribution and viscous force distribution are integrated to form the hydrodynamic yaw moment, which is used to drive the floating wind turbine (1) to yaw.

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