Integrated modeling method, system, and medium for floating wind turbines

Abstract

An integrated modeling method, system and medium for a floating wind turbine are disclosed. An integrated modeling method for a floating wind turbine includes obtaining an initial model of the floating wind turbine, the floating wind turbine including an upper turbine system, a tower, a floating platform, and a mooring system; and converting the initial model of the floating wind turbine into an integrated model of the floating wind turbine, including: converting initial model coordinates of the upper turbine system into a coordinate system of the tower to form a model of an upper turbine system portion in the integrated model; converting initial model coordinates of the floating platform into the coordinate system of the tower to form a model of a floating platform portion in the integrated model; converting initial model coordinates of the mooring system into the coordinate system of the tower to form a model of a mooring system portion in the integrated model; and constructing the integrated model based on the converted models of the upper turbine system portion, the floating platform portion, and the mooring system portion, and an initial model of the tower.

Description

Technical Field

[0001] This invention relates to the modeling and simulation of floating wind turbines, and more particularly to methods, systems and media for integrated modeling of floating wind turbines. Background Technology

[0002] Wind energy is a clean and renewable energy source that can reduce greenhouse gas emissions and address climate change. Offshore wind energy has attracted widespread attention due to its abundant resources and relatively more stable operation. As water depths increase to over 30 meters, floating wind turbines are becoming an economically viable alternative to stationary turbines.

[0003] However, floating wind turbines face numerous uncertainties such as wind, waves, and currents in the complex marine environment. To address the challenges these environmental factors pose to the stability and performance of floating wind turbines, engineers and researchers need to conduct extensive numerical simulations and model tests. Although existing time-domain simulation methods can simulate these complex operating conditions, their computational efficiency is not high, and the numerous design parameters and nonlinear coupling characteristics significantly increase computational complexity. Therefore, frequency-domain simulation methods, due to their high efficiency, have gradually become the ideal choice for preliminary design evaluation, sensitivity analysis, and design optimization of floating wind turbines.

[0004] While frequency domain simulation methods are relatively mature in traditional offshore industries such as oil and gas, they remain a significant technical challenge in the field of floating wind turbines. Early research methods primarily simulated the effects of simplified linear stiffness, damping, and added mass terms of the turbine. However, this approach did not adequately consider the additional added mass and damping effects generated by turbulent wind loads on the turbine blades at low frequencies, thus affecting the overall dynamic response of the turbine. Some studies have also found that the elastic support between the tower and the platform has a significant impact on the inherent properties of the tower. Although existing research has optimized the aerodynamic models of floating wind turbines to some extent, most studies still focus on the dynamic response of multi-rigid-body systems. Some researchers have attempted to simplify the turbine structure and use spectral methods to simulate its motion response. While this has been proven feasible to some extent, it ignores the various complex interactions and coupling effects within the turbine system, especially when capturing nonlinear behavior or conducting detailed fatigue analysis. Therefore, to ensure more accurate and reliable design and optimization of floating wind turbines, the motion response of the floating platform, as well as the performance of the upper tower and the turbine, must be comprehensively considered. Summary of the Invention

[0005] It should be understood that the above general description and the following detailed description of the invention are exemplary and illustrative, and are intended to provide further explanation of the invention as described in the claims.

[0006] According to one aspect of the present invention, an integrated modeling method for a floating wind turbine is provided, comprising: obtaining an initial model of the floating wind turbine, the floating wind turbine including an upper turbine system, a tower, a floating platform, and a mooring system; and converting the initial model of the floating wind turbine into an integrated model of the floating wind turbine, comprising: converting the coordinates of the initial model of the upper turbine system to the coordinate system of the tower to form a model of the upper turbine system portion in the integrated model; converting the coordinates of the initial model of the floating platform to the coordinate system of the tower to form a model of the floating platform portion in the integrated model; converting the coordinates of the initial model of the mooring system to the coordinate system of the tower to form a model of the mooring system portion in the integrated model; and constructing the integrated model based on the converted models of the upper turbine system portion, the floating platform portion, and the mooring system portion and the initial model of the tower.

[0007] According to another aspect of the present invention, an integrated modeling system for a floating wind turbine is provided, comprising: an initial model acquisition module for acquiring an initial model of the floating wind turbine, the floating wind turbine including an upper turbine system, a tower, a floating platform, and a mooring system; and an integrated model construction module for converting the initial model of the floating wind turbine into an integrated model of the floating wind turbine, including: converting the coordinates of the initial model of the upper turbine system to the coordinate system of the tower to form a model of the upper turbine system portion in the integrated model; converting the coordinates of the initial model of the floating platform to the coordinate system of the tower to form a model of the floating platform portion in the integrated model; converting the coordinates of the initial model of the mooring system to the coordinate system of the tower to form a model of the mooring system portion in the integrated model; and constructing the integrated model based on the converted models of the upper turbine system portion, the floating platform portion, and the mooring system portion and the initial model of the tower.

[0008] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium including code, which, when executed, causes a computer to perform the above-described method. Attached Figure Description

[0009] The accompanying drawings are included to provide a further understanding of the invention; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of the invention and, together with this specification, serve to explain the principles of the invention. In the drawings:

[0010] Figure 1 This is a flowchart of an integrated modeling method for floating wind turbines according to an embodiment.

[0011] Figure 2 This is a schematic diagram of flexible modeling of the tower according to an embodiment.

[0012] Figure 3 This is a schematic diagram illustrating the conversion of the initial model of the top wind turbine system, floating platform, and mooring system according to an embodiment.

[0013] Figure 4 This is a flowchart of an integrated modeling and frequency domain simulation method for floating wind turbines according to an embodiment.

[0014] Figure 5 This is a schematic diagram illustrating the external excitation effects on an integrated model of a floating wind turbine according to an embodiment.

[0015] Figure 6 This is a flowchart of the wind turbine aerodynamic added mass and wind turbine aerodynamic damping calculation method according to the embodiment.

[0016] Figure 7 This is a block diagram of an integrated modeling system for floating wind turbines according to an embodiment.

[0017] Figure 8 This is a block diagram of an integrated modeling and frequency domain simulation system for floating wind turbines according to an embodiment.

[0018] Figure 9 This is a comparison chart of floating platforms (RAO).

[0019] Figure 10 This is a comparison chart of the thrust spectrum at the top of the tower under different wind speeds.

[0020] Figure 11 It is a PSD comparison diagram of the swaying, heaving and pitching motions of a floating platform under wave conditions only.

[0021] Figure 12 This is a PSD comparison chart of wind turbine nacelle acceleration, tower bottom bending moment, and mooring force under combined wind and wave conditions. Detailed Implementation

[0022] Embodiments of the invention will now be described in detail with reference to the accompanying drawings, but the invention is not limited thereto but is defined solely by the claims. In the drawings, some elements may be enlarged and drawn out of scale for illustrative purposes. Wherever possible, the same reference numerals will be used in all drawings to denote the same or similar parts.

[0023] Although the terminology used in this invention is selected from commonly known and used terms, some terms mentioned in this specification may have been chosen by the applicant in his or her judgment, and their detailed meanings are explained in the relevant sections of the description herein. Furthermore, the invention should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0024] Numerous specific details are set forth in the description provided herein. However, it should be understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of the invention.

[0025] Currently, existing methods for modeling and frequency domain simulation of floating wind turbines often construct multi-rigid-body dynamic models by simplifying the turbine structure, but neglect the flexible characteristics of the tower and the resulting resonance coupling effect. The aerodynamic response of the upper wind turbine system due to turbulent wind excitation, the hydrodynamic viscosity effect of the floating platform, and the resistance and inertial effect of the mooring cable are often simplified or completely ignored. Furthermore, when the model needs to capture nonlinear behavior or conduct in-depth fatigue analysis, this simplification method may cause design decisions to deviate from the optimal path, or even produce unsafe results.

[0026] Therefore, in order to ensure that the design and optimization of floating wind turbine systems are both efficient and accurate, it is urgent to develop a new integrated modeling and frequency domain simulation method to comprehensively consider all components of floating wind turbines, especially the flexibility and vibration effects of the tower.

[0027] In view of the above problems, this invention proposes an innovative integrated modeling method and frequency domain simulation method for floating wind turbines. The core idea of ​​this invention is to treat the floating wind turbine system as a rigid-flexible coupled structure, thus providing a completely new perspective for its dynamic modeling. Compared with traditional modeling methods, the method of this invention is more accurate and detailed, not only accurately capturing the dynamic response of the floating wind turbine under various operating conditions, but also providing detailed insights into the structural response of the wind turbine. For example, using the method of this invention, phenomena such as bending, torsion, and local deformation of the wind turbine tower under aerodynamic and hydrodynamic load excitation can be clearly observed. This provides strong technical support for the design, optimization, and maintenance of floating wind turbines.

[0028] Figure 1 This is a flowchart of an integrated modeling method 100 for a floating wind turbine according to an embodiment of the present invention. The core objective of integrated modeling is to establish parametric models for the various components of the floating wind turbine. In step 102, an initial model of the floating wind turbine can be obtained. The floating wind turbine includes an upper turbine system, a tower, a floating platform, and a mooring system. The upper turbine system further includes components such as a rotor and a nacelle. The initial model of the floating wind turbine can be obtained through user input, software presets, or calculations based on the structural parameters and material properties of the floating wind turbine.

[0029] The following is an example of obtaining an initial model of a floating wind turbine. In one embodiment, obtaining an initial model of a floating wind turbine may include: obtaining the structural parameters and material properties of the floating wind turbine. The following are the relevant parameters for each component that need to be obtained:

[0030] Relevant parameters for the upper wind turbine system: Hub: Obtain the hub's radius, height, and its positioning relative to the tower top. Nacelle: Obtain the nacelle's axial tilt angle, yaw angle, and positioning relative to the tower top. Blades: Obtain parameters such as blade tip radius, number of blades, and blade cone angle. Furthermore, for each individual blade, blade element units are divided, and the radial position, chord length distribution, twist angle distribution, radial increment, airfoil number at that radial position, and corresponding airfoil information, such as angle of attack, drag coefficient, lift coefficient, and torque coefficient, are obtained.

[0031] Relevant parameters of the tower: Divide the tower into different tower units and obtain the coordinates and material properties of each unit, including: the density of the tower material, the length of the unit, the cross-sectional area, the elastic modulus, the shear modulus, and the moment of inertia of rotation about the unit cross-section in the horizontal, vertical and torsional directions.

[0032] Mass matrix and hydrostatic restoring stiffness matrix of floating platform.

[0033] Relevant parameters of the mooring system: obtain the coordinates of the guide hole and anchor point, diameter, density, stiffness, breaking force, lateral and tangential additional mass coefficients and drag coefficients of each mooring cable.

[0034] It should be understood that the structural parameters and material properties of the above components can be obtained by user input or through software presets, and the obtained parameters are not limited to those listed above.

[0035] In one embodiment, obtaining an initial model of the floating wind turbine may include: performing rigid and aerodynamic modeling of the upper wind turbine system based on its structural parameters and material properties to determine the initial model of the upper wind turbine system. Any suitable method can be used for rigid and aerodynamic modeling of the upper wind turbine system. In one embodiment, the initial model of the upper wind turbine system may include at least one of the following: the upper wind turbine system mass matrix, the aerodynamically added mass of the wind turbine rotor, and the aerodynamic damping of the wind turbine rotor.

[0036] In one embodiment, obtaining an initial model of a floating wind turbine may include: performing rigid or elastic modeling and hydrodynamic modeling of the floating platform based on its structural parameters and material properties to determine the initial model of the floating platform. When the floating platform is a large-volume platform, rigid modeling can be performed. When the floating platform is a slender platform, elastic modeling can be performed. Any suitable method can be used for rigid or elastic modeling and hydrodynamic modeling of the floating platform. In one embodiment, the initial model of the floating platform may include at least one of the following: the floating platform mass matrix, the floating platform hydrodynamic added mass, the floating platform potential flow damping, the floating platform hydrodynamic viscous damping, and the floating platform hydrostatic restoring force stiffness matrix.

[0037] In one embodiment, obtaining an initial model of a floating wind turbine may include: rigidly modeling the mooring system based on its structural parameters and material properties to determine the initial model. Any suitable method can be used to rigidly model the mooring system. In one embodiment, the initial model of the mooring system may include a restoring stiffness matrix. The following describes an example method for rigidly modeling a mooring system. In marine engineering, mooring systems are key components for positioning and stabilizing floating structures. From a structural dynamics perspective, a mooring system can be modeled as a nonlinear spring whose primary function is to provide horizontal restoring forces to resist the motion of the floating body caused by environmental loads (such as wind, waves, and currents). The restoring stiffness matrix of the mooring system can be used to describe the restoring forces generated when the mooring system is subjected to displacement or rotation. This restoring stiffness matrix is ​​typically a 6x6 matrix that combines linear stiffness (corresponding to displacement) and angular stiffness (corresponding to rotation). The restoring stiffness matrix K of the mooring system is described below. m It can be obtained from the following formula:

[0038] {F m (δ)}={F m}-[K m ]{δ} (Formula 1)

[0039] Where F m It is the load force of the mooring system in the unoffset position; F m (δ) represents the anchor chain tension of the floating wind turbine system after it deviates from its equilibrium position due to external load excitation; K m {δ} represents the restoring stiffness matrix of the mooring system; {δ} represents the displacement of the floating wind turbine system from its initial position under external load excitation. Wherein, the mooring tension F... m The value of (δ) can be obtained by using the quasi-static catenary method, the lumped mass method, or by using professional analysis software (Orcaflex and OpenFAST).

[0040] In one embodiment, obtaining an initial model of a floating wind turbine may include: performing flexible modeling of the tower based on its structural parameters and material properties to determine the initial model of the tower. Any suitable method can be used for flexible modeling of the tower. In one embodiment, the initial model of the tower may include at least one of a tower mass matrix, a tower structural damping matrix, and a tower stiffness matrix. Example methods for performing flexible modeling of the tower are described below. Figure 2 This is a schematic diagram of flexible modeling of a tower according to an embodiment of the present invention. In flexible modeling, the tower is simulated as a three-dimensional nonlinear beam, and further subdivided into N three-dimensional beam elements, thereby constructing a detailed and flexible tower model. In this model, each three-dimensional beam element is defined by two nodes, representing a small segment of the tower. For each three-dimensional beam element, a stiffness matrix and a mass matrix are formed at the two end nodes according to its geometry, material properties, and constraints. Each node has six degrees of freedom, which describes its translational and rotational dynamics in three-dimensional space in detail, providing a solid foundation for a comprehensive analysis of the system's dynamic interactions. Furthermore, based on the small deformation assumption, these matrices are mapped to the global coordinate system to ensure the accuracy of the model, laying the foundation for subsequent structural dynamics analysis and contributing to a deeper understanding of the tower's performance.

[0041] Based on the tower's geometry, material properties, and constraints, a corresponding mass matrix [M′] can be constructed at the two end nodes of each element. k and stiffness matrix [K′] k Based on the small deformation assumption, the mass and stiffness matrices in the local coordinate system can be mapped to the global coordinate system:

[0042] [M] k =[T k ] T [M′] k [T k [K] k =[T k ] T [K′] k [T k ] (Formula 2)

[0043] Among them, [M] k and [K] k These are the mass and stiffness matrices of element k in the global coordinate system. [T] k The ] represents the corresponding transformation matrix:

[0044]

[0045] Where [T0] is the direction cosine matrix for transforming the local coordinate system to the global coordinate system:

[0046]

[0047] In this transformation matrix, lowercase xyz represents the coordinate axes in the local coordinate system (usually the x, y, and z axes), while uppercase XYZ represents the coordinate axes in the global coordinate system (usually the X, y, and Z axes). Taking the element cos(x′X) as an example, it represents the projection of the local x-axis (x') onto the global x-axis. The mass and stiffness matrices of an element can be grouped according to the number of nodes in the element. For example, the mass and stiffness matrices of the k-th element can be represented as:

[0048]

[0049] Each element in the matrix is ​​a 6x6 matrix. By combining the mass and stiffness matrices of the N elements of the tower, the tower mass matrix M of the entire tower can be obtained. s and tower stiffness matrix K s .

[0050] According to embodiments of the present invention, the Rayleigh damping method can be used to obtain the global structural damping matrix for a tower structure. Rayleigh damping is a commonly used damping model that obtains the global structural damping matrix M of the system by using the Rayleigh damping method. s and stiffness matrix K s Combining to obtain the tower structure damping matrix C s As shown below:

[0051] [C s ]=α1[M s ]+α2[K s ] (Formula 6)

[0052] Here, α1 and α2 are the mass and stiffness proportionality coefficients, respectively. Rayleigh damping represents a linear combination of mass and stiffness proportional damping, providing a practical and general framework for quantifying and analyzing the complex dynamic behaviors and interactions involved. In other embodiments, methods such as direct construction can also be used to obtain the tower's damping matrix. The above flexible modeling of the tower not only provides the tower's physical characteristics and behavior but also ensures the accuracy and reliability of the overall model.

[0053] return Figure 1 In step 104, the initial model of the floating wind turbine can be converted into an integrated model of the floating wind turbine.

[0054] In one embodiment, step 104 may include: transforming the initial model coordinates of the upper wind turbine system to the tower coordinate system to form a model of the upper wind turbine system portion in the integrated model, transforming the initial model coordinates of the floating platform to the tower coordinate system to form a model of the floating platform portion in the integrated model, and transforming the initial model coordinates of the mooring system to the tower coordinate system to form a model of the mooring system portion in the integrated model. Figure 3 This is a schematic diagram illustrating the conversion of an initial model of the top wind turbine system, floating platform, and mooring system according to an embodiment of the present invention. Figure 3 As shown, based on the established flexible tower model of the floating wind turbine, the upper wind turbine system can be transformed to the upper node of the tower, and the floating platform and mooring system can be transformed to the lower node of the tower, so as to discuss the entire floating wind turbine in the tower coordinate system.

[0055] In one embodiment, a coordinate transformation matrix can be used to perform beam-node transformations on the properties of the upper wind turbine system and the floating platform, encompassing their structural characteristics and displacement relationships. This involves the mass and stiffness matrices of the upper wind turbine system (including the rotor and nacelle assembly, RNA) and the floating platform. In one embodiment, a first coordinate transformation matrix T1 can be used to transform the initial model coordinates of the floating platform to the tower coordinate system, and a second coordinate transformation matrix T2 can be used to transform the initial model coordinates of the upper wind turbine system to the tower coordinate system. The transformed displacement relationships of the floating platform at the lower node of the tower and the upper wind turbine system at the upper node of the tower are described below:

[0056] {δ platform′}=[T1]{δ platform},{δ RNA′}=[T2]{δ RNA} (Formula 7)

[0057]

[0058] Where {δ platform} represents the displacement of the floating platform, {δ RNA} represents the displacement of the upper fan system, {δ platform′} represents the displacement of the floating platform in the tower coordinate system, {δ RNA′} represents the displacement of the upper wind turbine system in the tower coordinate system. In Equation 8, for a floating platform i=1, Δx i ,Δy i and Δz i The distance between the floating platform's center of mass and the tower base in the tower coordinate system is represented by the global coordinates of the floating platform, explicitly defining the relative positional relationship between the floating platform and the tower base; for the upper wind turbine system i=2, Δxi ,Δy i and Δz i The coordinate transformation matrix represents the distance between the global coordinates of the upper turbine system's center of mass in the tower coordinate system and the tower top, explicitly defining the relative positional relationship between the upper turbine system and the tower top. This coordinate transformation matrix provides a mathematically precise description of the displacement and positional changes of the upper turbine system and the floating platform in their respective coordinate systems. Through this matrix, the spatial positioning and dynamic behavior of the upper turbine system relative to the tower top and the floating platform relative to the tower bottom in their local coordinate systems can be analyzed in depth. Furthermore, the coordinate transformation matrix provides a mathematical framework for the transformation of the structural parameters (mass matrix and stiffness matrix) of both components at the upper and lower endpoints of the tower model. This approach provides a powerful analytical tool capable of revealing the complex interactions and dynamic characteristics of these components under various environmental conditions. Employing the coordinate transformation matrix ensures proper alignment and transformation of components. In one embodiment, a first coordinate transformation matrix T1 can also be used to transform the initial model coordinates of the mooring system to the tower coordinate system.

[0059] return Figure 1 Step 104 may further include constructing an integrated model of the floating wind turbine based on the transformed models of the upper turbine system, floating platform, and mooring system, and the initial model of the tower. In one embodiment, the integrated model of the floating wind turbine may include at least one of a global mass matrix, a global damping matrix, and a global stiffness matrix. In one embodiment, the global mass matrix may be a combination of the coordinate-transformed upper turbine system mass matrix, the coordinate-transformed rotor aerodynamic added mass, the coordinate-transformed floating platform mass matrix, the coordinate-transformed floating platform hydrodynamic added mass, and the tower mass matrix. In one embodiment, the global damping matrix may be a combination of the coordinate-transformed rotor aerodynamic damping, the coordinate-transformed floating platform potential flow damping, the coordinate-transformed floating platform hydrodynamic viscous damping, and the tower structural damping. In one embodiment, the global stiffness matrix may be a combination of the coordinate-transformed floating platform hydrostatic restoring force stiffness matrix, the coordinate-transformed mooring system restoring force stiffness matrix, and the tower stiffness matrix. The following are examples of the global mass matrix [M], global damping matrix [C], and global stiffness matrix [K] of the integrated model:

[0060] [M] = [M] s ]+[M r [T2]+[M P [T1]+[A p [T1]+[A r [T2]

[0061] [C] = [C s ]+[C p[T1]+[C r [T2]+[C v ][T1] (Formula 9)

[0062] [K]=[K s ]+[K p [T1]+[K m [T1]

[0063] Where M s M r , and M P These are the tower mass matrix, the upper wind turbine system mass matrix, and the floating platform mass matrix, respectively; A p and A r These are the hydrodynamic added mass of the floating platform and the aerodynamic added mass of the wind turbine, respectively; C s C p C r and C v These are, respectively, tower structure damping, floating platform potential flow damping, wind turbine aerodynamic damping, and floating platform hydrodynamic viscous damping; K s ,K p and K m These are the tower stiffness matrix, the floating platform still water restoring force stiffness matrix, and the mooring system restoring force stiffness matrix, respectively; T1 and T2 are the first coordinate transformation matrix and the second coordinate transformation matrix, respectively.

[0064] After performing integrated modeling of the floating wind turbine to obtain an integrated model of the floating wind turbine, in order to simulate the integrated model, the corresponding motion equations can be established in the frequency domain framework based on integrated modeling and linear system theory to evaluate the dynamic response of the wind turbine in the marine environment. Figure 4 This is a flowchart of an integrated modeling and frequency domain simulation method 400 for floating wind turbines according to an embodiment of the present invention. Steps 402 to 404 are consistent with reference to... Figure 1 Steps 102 to 104 in the described method 100 are the same. To avoid redundancy, the specific details of steps 402 to 404 will not be repeated here.

[0065] To simulate the integrated model, energy spectra of various environmental loads (such as wind and waves) can be established within the frequency domain. Utilizing potential flow theory and related hydrodynamic models, combined with the structural dynamic characteristics of the wind turbine (such as mass, stiffness, and damping), a system response model can be established in the frequency domain. Based on the model obtained from the embodiments of this invention, the dynamic response of the floating wind turbine at various frequencies, such as the frequency response functions of displacement, velocity, and acceleration, can be further calculated for data analysis and mining. The advantages of this method lie in its computational efficiency and in-depth understanding of the system's dynamic characteristics.

[0066] Figure 5 This is a schematic diagram illustrating the external excitation effects on an integrated model of a floating wind turbine according to an embodiment of the present invention. Figure 5 As shown, the external excitations include wind loads applied to the upper wind turbine system, wind loads applied to the tower, and wave loads and ocean current loads applied to the floating platform and mooring system. Therefore, it is necessary to perform aerodynamic and hydrodynamic modeling of the external excitations of the floating wind turbine.

[0067] return Figure 4 In step 406, aerodynamic modeling can be performed on the upper wind turbine system and tower to determine the aerodynamic loads on the upper structure.

[0068] In one embodiment, aerodynamic modeling of the upper wind turbine system to determine the initial model of the upper wind turbine system may include a global calculation matrix for calculating the aerodynamic added mass of the turbine rotor and a global calculation matrix for the aerodynamic damping of the turbine rotor. The aerodynamic added mass and aerodynamic damping of the turbine rotor are crucial for accurately predicting the dynamic response of floating wind turbines, as they directly affect the vibration characteristics of the upper wind turbine system under wind loads. A series of methods have been developed for modeling and analyzing the aerodynamic added mass and aerodynamic damping of the turbine rotor, but these methods often involve averaging or simplifying calculations. For example, existing integrated fully coupled time-domain simulations provide a framework for the aerodynamic added mass and aerodynamic damping effects of floating wind turbines, but these methods do not provide direct quantitative calculation methods. This results in a lack of frequency domain analysis methods for floating wind turbines, complicating the preliminary design process, requiring multiple iterations, and consuming significant time and resources. Current calculation methods often lack explicit analytical forms, making the calculation process slow and difficult to adapt to various design and operating conditions. Furthermore, many simplification methods ignore the dynamic effects of the controller and the influence of different motion frequencies, which may lead to misjudgments of aerodynamic effects. To more accurately predict the dynamic response of floating wind turbines, it is necessary to directly and accurately assess aerodynamic effects and take into account the influence of controllers and motion frequencies.

[0069] In modeling the aerodynamic added mass and aerodynamic damping of a floating wind turbine using frequency domain simulation methods, the dynamic response and motion frequency of the controller have a significant impact on these parameters. The controller's dynamic effects directly adjust the turbine's operation to cope with wind or wave disturbances and ensure its stability. This adjustment may alter the turbine's dynamic characteristics, thereby affecting the aerodynamic added mass and aerodynamic damping. Different motion frequencies also produce different effects on these parameters: low-frequency motion may enhance the aerodynamic added mass due to the stronger interaction between the turbine and the air; while high-frequency motion may increase the aerodynamic damping due to increased air resistance caused by the turbine's rapid dynamic behavior. Therefore, this invention considers the controller's dynamic effects and the influence of different motion frequencies, integrating the aerodynamic added mass and aerodynamic damping of the floating wind turbine into an integrated frequency domain simulation method.

[0070] Figure 6 This is a flowchart of a method 600 for calculating the aerodynamic added mass and aerodynamic damping of a wind turbine according to an embodiment of the present invention. In step 602, input variables are received, including the incident wind speed and the reciprocating motion frequency. In step 604, controller parameters are determined, including the wind turbine speed, blade pitch angle, proportional gain coefficient, integral gain coefficient, and gear ratio. In step 606, the moment of inertia is determined. In step 608, wind turbine parameters are determined, including chord length distribution, twist angle distribution, and lift / drag coefficient. In step 610, based on the wind turbine parameters and controller parameters, the first-order partial derivatives of the aerodynamic loads are determined according to blade element momentum theory, including the first-order partial derivatives of aerodynamic thrust and aerodynamic torque with respect to the incident wind speed, wind turbine speed, and blade angle, as well as the partial derivative of the generator torque with respect to the wind turbine speed. In step 612, it is determined whether the controller is in the generator torque adjustment stage or the blade pitch adjustment stage. In step 614, the aerodynamic added mass A of the wind turbine at the incident wind speed is determined. r And wind turbine aerodynamic damping C r .

[0071] To accurately simulate the aerodynamic characteristics under servo control during wind turbine operation, this invention divides the calculation of wind turbine aerodynamic characteristics into two stages: the power generation torque adjustment stage and the blade pitch adjustment stage. For each of these two stages, the aerodynamic added mass 'a' of the wind turbine is calculated according to the following formula. r And wind turbine aerodynamic damping c r :

[0072] Generation torque regulation stage:

[0073]

[0074] Blade pitch adjustment stage:

[0075]

[0076] Where ω represents the frequency of the reciprocating motion; β represents the paddle pitch angle; T V T Ω T β Q v Q Ω Q β Let I represent the first-order partial derivatives of aerodynamic thrust and aerodynamic torque with respect to incident wind speed, rotor speed, and blade angle, respectively; d N represents the moment of inertia of the low-speed drive shaft. g Indicates the gear ratio; τ Ω K represents the partial derivative of the generator torque with respect to the wind turbine speed. p and K i These are the proportional gain coefficient and the integral gain coefficient, respectively.

[0077] Under uniform wind conditions, considering the forced harmonic motion of the rotating wind turbine, the fluctuation characteristics of the turbine thrust are derived using blade element momentum theory. This derivation is based not only on the average wind speed but also on the motion frequency. To accurately obtain the aerodynamic added mass and aerodynamic damping of the turbine, a first-order Taylor expansion method is used to extract their analytical expressions. During this process, changes in the turbine's rotational speed and blade angle are also considered, as they directly affect the fluctuation of the turbine thrust. To simulate various motion frequencies, forced harmonic motion is applied at the turbine-nacelle junction to simulate the effects of different frequencies. In summary, this method not only reveals the fluctuation characteristics of the turbine thrust but also more accurately evaluates the aerodynamic added mass and aerodynamic damping of the turbine, providing a theoretical basis for the design and optimization of floating wind turbines.

[0078] The following table shows the basic characteristics of the wind turbine's aerodynamic added mass and aerodynamic damping, obtained according to the above calculation method.

[0079] Table 1. Basic Characteristics of Wind Turbine Aerodynamic Added Mass and Wind Turbine Aerodynamic Damping

[0080]

[0081] It should be understood that the calculation of the aerodynamic added mass and aerodynamic damping of the wind turbine is not limited to the above methods. Other methods such as theoretical analysis (implicit analysis), numerical simulation and model test can also be used to obtain the aerodynamic added mass and aerodynamic damping of the wind turbine.

[0082] By incorporating aerodynamic effects into fully coupled integrated frequency domain simulation calculations, a model can be established regarding the aerodynamic added mass A of the wind turbine. r The global calculation matrix and the wind turbine aerodynamic damping C r Global computation matrix:

[0083]

[0084] in and The aerodynamic added mass a of the wind turbine r With wind turbine aerodynamic damping c r It is located at node N+1 in the global matrix.

[0085] The following describes a method for aerodynamic modeling of the upper wind turbine system and tower to determine the aerodynamic loads on the upper structure.

[0086] Aerodynamic modeling can include modeling the wind loads on the rotor and the tower. Regarding the wind loads on the rotor, aerodynamic excitation load modeling and aerodynamic thrust spectrum modeling can be performed. Aerodynamic excitation load modeling can include modeling the cross-spectral density function between rotor rotation and wind speed in the upper wind turbine system, which is crucial for understanding the performance changes and potential nonlinear effects of the rotor at different wind speeds. Relative wind speed is the main factor generating thrust. For aerodynamic calculations in the integrated frequency domain model of a floating wind turbine, it is first necessary to obtain the cross-spectral density function between wind speed and rotor rotation between two adjacent blade elements on a single blade, as shown in Equation 13:

[0087]

[0088] Among them, S U (ω) represents the inflow wind spectrum; ω is the frequency; Ω represents the rotor speed; i and j represent two different blade element units; ψ represents the azimuth angle between different blade element units; n F For the relevant frequency domain Fourier variables; It is the nth Fourier coefficient of the coherence function γ, and can be Fourier expanded on the wind turbine:

[0089]

[0090] Where θ is the differential of the independent variable. The coherent function with an interval distance of d and a frequency of fHz can be calculated using Equation 15:

[0091]

[0092] U hub The average wind speed at the hub height; L c Here is the autocorrelation scaling coefficient. It should be understood that the above coherence function is merely an example of this application; other exponential empirical formulas and other methods can also be used to calculate the coherence function. Formula 13 can be rewritten as:

[0093]

[0094] Where B represents the number of leaves.

[0095] Aerodynamic thrust spectrum modeling is a key component in predicting the stability and performance of wind turbines in complex wind fields. This is achieved through the wind thrust transformation matrix W. iT Cross spectrum obtained in aerodynamic excitation load modeling The thrust spectrum is then obtained through processing. The formula is as follows:

[0096]

[0097] Where Δr is the distance between two leaf element units. F n,v (r i ) is r i The partial derivative of the aerodynamic thrust of the blade element with respect to the incident wind speed is given. Therefore, the wind load on the wind turbine can be obtained by modeling the aerodynamic excitation load and the aerodynamic thrust spectrum.

[0098] Because the tower of a floating wind turbine is also affected by wind loads, the wind load on the tower... The calculation can be obtained through various common methods. For example, wind force can be characterized using the power spectral density of wind speed; the dynamic response of the tower to wind loads (including vibration modes and frequency response) can be evaluated using structural dynamics models; and the frequency response of wind loads can be obtained by applying a frequency response function to convert the power spectral density of wind speed into the power spectral density of wind loads. Therefore, the aerodynamic loads of the superstructure can be obtained.

[0099]

[0100] return Figure 4 In step 408, hydrodynamic modeling can be performed on the floating platform and mooring system to determine the hydrodynamic loads on the substructure.

[0101] In one embodiment, hydrodynamic modeling of the floating platform to determine the initial model of the floating platform may include hydrodynamic coefficient modeling of the floating platform to obtain the hydrodynamic added mass A of the floating platform. p And floating platform potential flow damping C pIn some embodiments, hydrodynamic coefficients can be obtained using common marine engineering software and methods such as model testing. Examples include numerical simulation (e.g., using marine engineering software such as WAMIT, AQWA, or HydroSTAR for frequency domain hydrodynamic analysis), model testing (e.g., obtaining hydrodynamic added mass and damping by testing a scaled-down model in an experimental tank and measuring the model's response under different wave conditions), analytical solutions (e.g., directly calculating hydrodynamic added mass and damping using analytical formulas for simple geometries and flow conditions), computational fluid dynamics (CFD) simulations (e.g., using CFD software), and so on. It should be understood that this application can use any suitable method to model the hydrodynamic coefficients of a floating platform, and is not limited to the methods shown above.

[0102] In one embodiment, hydrodynamic modeling of the floating platform to determine the initial model of the floating platform may include obtaining the hydrodynamic viscous damping of the floating platform. The calculation of the hydrodynamic viscous force in this application can employ various methods, such as the Morison equation or a linearized viscous damping matrix, to obtain the hydrodynamic viscous damping C of the floating platform. v .

[0103] Hydrodynamic modeling can include modeling wave loads and ocean current loads on floating platforms. Regarding wave load modeling for floating platforms, the following is the theoretical process for modeling wave excitation forces:

[0104]

[0105] Wave excitation force It is usually divided into first-order wave excitation force Second-order difference frequency wave excitation force Second-order sum-frequency wave excitation force and viscous force These correspond to linear and nonlinear wave effects, respectively. Viscous force. It can be obtained through calculations using the Morrison equation and linearized viscous damping matrix. Based on linear potential flow theory, the first-order wave force transfer function... This can be obtained through analysis using frequency domain hydrodynamic software (e.g., WAMIT, AQWA, etc.), representing the first-order wave force generated per unit wave at a specific wave frequency ω and wave direction angle θ. The first-order wave force transfer function is related to the wave spectrum S. ξ The relationship between (ω) can be obtained through the Wiener-Khinchin theorem, and the relevant calculation is shown in Equation 22:

[0106]

[0107] Where D(θ) is the direction distribution function. Under short-crest wave conditions, the second-order difference-frequency force of waves is affected by multi-wave-direction coupling, but its main component comes from the direction of the main incoming wave, so the related wave-direction coupling response can be ignored. Therefore, the calculation of the second-order wave excitation force in this method can be obtained by the full second-order wave force transfer function (QTF) method or the Newman approximation method, etc. It should be understood that this application can use any appropriate method to model the wave excitation load, and is not limited to the methods shown above. Based on the above modeling, the wave load on the floating platform can be obtained.

[0108] Ocean current loads on floating platforms For example, the response of a floating wind turbine to wave forces (including the frequency spectra of first- and second-order wave forces) can be simulated in the frequency domain by treating the ocean current as a constant force and estimating based on the ocean current velocity and the hydrodynamic characteristics of the wind turbine, taking into account the influence of the ocean current on wave characteristics, especially the effect of the ocean current on wave morphology (where necessary).

[0109] Therefore, the hydrodynamic loads of the substructure can be obtained.

[0110]

[0111] At step 410, the equations of motion for the floating wind turbine can be constructed based on the integrated model, the aerodynamic loads on the superstructure, and the hydrodynamic loads on the substructure. In one embodiment, the equations of motion are:

[0112]

[0113] Where δ is the displacement of the floating wind turbine, and F areo and F hydro These represent the aerodynamic loads on the superstructure and the hydrodynamic loads on the substructure, respectively. Using the above equations, the mean dynamic response of the floating wind turbine system can also be calculated, thus providing a rapid evaluation method for its preliminary design optimization: K{δ}={F aero}+{F hydro}

[0114] Taking a Fourier transform of the equation of motion (Equation 24) yields the frequency-dependent equation of motion:

[0115]

[0116] Where ω is the operating frequency of the floating wind turbine. This represents the displacement δ of a floating wind turbine in the frequency domain. Using the above equations, dynamic response analysis can be performed on an integrated model of the floating wind turbine. For example, Equation 25 can be used to accurately calculate the displacement response of beam element nodes under various external excitation loads (such as waves, wind, or ocean currents). This displacement response is represented as a displacement spectrum in the frequency domain. In some embodiments, to quantify the characteristics of these responses, the power spectral density (PSD) can be used to describe the frequency content of the displacement. The PSD provides the expected value of the square of the displacement amplitude at each frequency, thus revealing the energy distribution of the system at different frequencies. In some embodiments, to obtain the overall dynamic characteristics of the system, the spectral area can be further calculated. Based on the above PSD results, the PSD response spectra of each component of the floating wind turbine system can also be obtained, including nacelle acceleration, tower base bending moment, and mooring force. Furthermore, fatigue calculation is a crucial step in assessing potential damage to the structure under cyclic loading. For marine structures, such as floating wind turbines, fatigue is caused by waves, wind, and other cyclic loads. Power spectral density provides the fundamental data for fatigue analysis. The main advantage of fatigue analysis within the frequency domain framework is efficiency. Compared to time-domain analysis, frequency-domain analysis can handle long-term load histories much faster. The specific process is as follows: First, spectral moments, particularly the zeroth, first, and second-order spectral moments, are calculated using the PSD (Power Scaling Spectrum). These spectral moments provide crucial data for subsequent fatigue analysis. Second, based on the spectral moments and appropriate fatigue theory, the converted load range can be calculated. This is a representative load range that can lead to fatigue damage similar to the actual load history. Using the converted load range and SN (Strain-Negative) curves, the fatigue damage spectrum can be calculated in the frequency domain. This describes the expected fatigue damage at each frequency. Finally, by integrating the fatigue damage spectrum across the entire frequency range, the total fatigue damage can be obtained. This typically involves integrating the fatigue damage spectrum. Based on the accumulated fatigue damage, the fatigue life of the structure can be predicted. This indicates how long the structure is expected to function normally under current load conditions without failing due to fatigue. By using an integrated frequency-domain simulation framework, external excitation loads can be accurately simulated, thereby constructing the motion equations of the entire floating wind turbine system for analyzing the system's comprehensive dynamic response, such as platform motion, tower vibration, mooring tension, nacelle acceleration, etc.

[0117] Figure 7This is a block diagram of an integrated modeling system 700 for floating wind turbines according to an embodiment of the present invention. System 700 may include an initial model acquisition module 702 and an integrated model construction module 704. The initial model acquisition module 702 can be used to acquire an initial model of the floating wind turbine, which includes an upper turbine system, a tower, a floating platform, and a mooring system. The integrated model construction module 704 can be used to convert the initial model of the floating wind turbine into an integrated model of the floating wind turbine, including: converting the coordinates of the initial model of the upper turbine system to the coordinate system of the tower to form a model of the upper turbine system portion in the integrated model; converting the coordinates of the initial model of the floating platform to the coordinate system of the tower to form a model of the floating platform portion in the integrated model; converting the coordinates of the initial model of the mooring system to the coordinate system of the tower to form a model of the mooring system portion in the integrated model; and constructing an integrated model based on the converted models of the upper turbine system portion, the floating platform portion, and the mooring system portion, and the initial model of the tower.

[0118] In one embodiment, the initial model of the upper turbine system may include at least one of the following: the upper turbine system mass matrix, the aerodynamic added mass of the turbine rotor, and the aerodynamic damping of the turbine rotor; the initial model of the floating platform may include at least one of the following: the floating platform mass matrix, the floating platform hydrodynamic added mass, the floating platform potential flow damping, the floating platform hydrodynamic viscous damping, and the floating platform hydrostatic restoring stiffness matrix; the initial model of the mooring system may include the mooring system restoring stiffness matrix; and the initial model of the tower may include at least one of the following: the tower mass matrix, the tower structural damping, and the tower stiffness matrix.

[0119] In one embodiment, the integrated model may include at least one of a global mass matrix, a global damping matrix, and a global stiffness matrix, wherein the global mass matrix is ​​composed of a coordinate-transformed upper turbine system mass matrix, a coordinate-transformed rotor aerodynamic added mass, a coordinate-transformed floating platform mass matrix, a coordinate-transformed floating platform hydrodynamic added mass, and a tower mass matrix; wherein the global damping matrix is ​​composed of a coordinate-transformed rotor aerodynamic damping, a coordinate-transformed floating platform potential flow damping, a coordinate-transformed floating platform hydrodynamic viscous damping, and a tower structural damping; and wherein the global stiffness matrix is ​​composed of a coordinate-transformed floating platform hydrostatic restoring force stiffness matrix, a coordinate-transformed mooring system restoring force stiffness matrix, and a tower stiffness matrix.

[0120] In one embodiment, the global mass matrix, global damping matrix, and global stiffness matrix can be as follows:

[0121] [M] = [M] s ]+[M r [T2]+[M P[T1]+[A p [T1]+[A r [T2]

[0122] [C]=[C s ]+[C p [T1]+[C r [T2]+[C v [T1]

[0123] [K]=[K s ]+[K p [T1]+[K m [T1]

[0124] Where M, C, and K are the global mass matrix, global damping matrix, and global stiffness matrix, respectively. s M r , and M p These are the tower mass matrix, the upper wind turbine system mass matrix, and the floating platform mass matrix, respectively; A p and A r These are the hydrodynamic added mass of the floating platform and the aerodynamic added mass of the wind turbine, respectively; C s C p C r and C v These are, respectively, tower structure damping, floating platform potential flow damping, wind turbine aerodynamic damping, and floating platform hydrodynamic viscous damping; K s ,K p and K m These are the tower stiffness matrix, the floating platform still water restoring force stiffness matrix, and the mooring system restoring force stiffness matrix, respectively; T1 and T2 are the first coordinate transformation matrix and the second coordinate transformation matrix, respectively.

[0125] In one embodiment, obtaining an initial model of a floating wind turbine may include: obtaining the structural parameters and material properties of the floating wind turbine; performing rigid and aerodynamic modeling of the upper wind turbine system based on the structural parameters and material properties of the upper wind turbine system to determine the initial model of the upper wind turbine system; performing rigid or elastic and hydrodynamic modeling of the floating platform based on the structural parameters and material properties of the floating platform to determine the initial model of the floating platform; performing rigid modeling of the mooring system based on the structural parameters and material properties of the mooring system to determine the initial model of the mooring system; and performing flexible modeling of the tower based on the structural parameters and material properties of the tower to determine the initial model of the tower.

[0126] In one embodiment, aerodynamic modeling of the upper wind turbine system may include: calculating the aerodynamic added mass A of the wind turbine rotor. r The global calculation matrix and the wind turbine aerodynamic damping C r The global computation matrix,

[0127]

[0128] During the torque regulation phase, the following formula is used for calculation:

[0129]

[0130] During the blade pitch adjustment phase, the following formula is used for calculation:

[0131]

[0132] Where ω represents the frequency of the reciprocating motion; β represents the paddle pitch angle; T V T Ω T β Q v Q Ω Q β Let I represent the first-order partial derivatives of aerodynamic thrust and aerodynamic torque with respect to incident wind speed, rotor speed, and blade angle, respectively; d N represents the moment of inertia of the low-speed drive shaft. g Indicates the gear ratio; τ Ω K represents the partial derivative of the generator torque with respect to the wind turbine speed. p and K i These are the proportional gain coefficient and the integral gain coefficient, respectively.

[0133] Figure 8 This is a block diagram of an integrated modeling and frequency domain simulation system 800 for floating wind turbines according to an embodiment of the present invention. The system 800 may include an initial model acquisition module 802, an integrated model construction module 804, an aerodynamic modeling module 806, a hydrodynamic modeling module 808, and a motion equation construction module 810.

[0134] Initial model acquisition module 802 to integrated model construction module 804 and reference Figure 7 The initial model acquisition module 702 to the integrated model construction module 704 in the described system 700 are identical. To avoid redundancy, the specific details of the initial model acquisition module 802 to the integrated model construction module 804 will not be elaborated here.

[0135] The aerodynamic modeling module 806 can perform aerodynamic modeling of the upper wind turbine system and tower to determine the aerodynamic loads on the upper structure.

[0136] The hydrodynamic modeling module 808 can perform hydrodynamic modeling on floating platforms and mooring systems to determine the hydrodynamic loads on the substructure.

[0137] The kinematic equation construction module 810 can construct the kinematic equations of a floating wind turbine based on the integrated model, the aerodynamic loads of the upper structure, and the hydrodynamic loads of the lower structure.

[0138] In one embodiment, the equation of motion is:

[0139]

[0140] Where M, C, and K are the global mass matrix, global damping matrix, and global stiffness matrix of the integrated model, respectively, δ is the displacement of the floating wind turbine, and F... aero and F hydro The aerodynamic loads on the superstructure and the hydrodynamic loads on the substructure are respectively considered. A Fourier transform is performed on the equations of motion to obtain the frequency-dependent equations of motion. The frequency-dependent equations of motion are as follows:

[0141]

[0142] Where ω is the operating frequency of the floating wind turbine. Let δ represent the displacement of the floating wind turbine in the frequency domain.

[0143] Table 2 below shows a comparison of the inherent period of a floating wind turbine system using a time-domain simulation method and a frequency-domain simulation method according to an embodiment of the present invention. As can be seen from the table, the frequency-domain simulation method according to an embodiment of the present invention can achieve accuracy comparable to the time-domain simulation method.

[0144] Table 2 Comparison of the inherent periods of time-domain simulation methods and frequency-domain simulation methods

[0145]

[0146]

[0147] The OC4 DeepCwind semi-submersible floating wind turbine system is used as a verification model in the following comparison of the results of the time-domain method with the integrated modeling and frequency-domain simulation method according to an embodiment of the present invention. The floating wind turbine system operates in a water depth of 200m, with a power of 5MW for the upper turbine, and cut-in and cut-out wind velocities of 3m / s and 25m / s, respectively. The RNA is located 2.4 meters above the top of the tower, the tower height is 77.6 meters, and the tower base elevation is 10.0 meters above the average still water level.

[0148] Figure 9 This is a comparison chart of floating platforms (RAO). Figure 10 This is a comparison diagram of the thrust spectrum at the top of the tower when the turbulent wind speed is 8 m / s, 11.4 m / s and 14 m / s. Figure 11 This is a PSD comparison chart of the swaying, heaving, and rolling motions of a floating platform under wave conditions only. The sea state information is a meaningful wave height of 7.4m and a wave period of 12.0s. The left side is the case considering only the first-order wave force, and the right side is the case considering both the first-order and second-order wave forces. Figure 12 This is a PSD comparison chart of wind turbine nacelle acceleration, tower base bending moment, and mooring force under different operating conditions of wind and waves. Figures 9-12 It can be seen that the frequency domain simulation method of the present invention can achieve accuracy comparable to that of the time domain method under different operating conditions.

[0149] This invention employs dynamic modeling of flexible towers and integrates rapid frequency domain simulation technology for floating wind turbines, enabling the rapid determination of the tower's natural frequencies considering the influence of the floating body and in-depth analysis of the impact of the flexible tower on the wind turbine under different operating conditions. This method not only accurately and rapidly simulates the dynamic response of the entire tower-wind turbine system but also provides engineers and researchers with in-depth insights into the structural response of the wind turbine. For example, using the method of this invention, the bending, torsion, and local deformation behaviors of the wind turbine tower under wind and wave loads can be visually observed. Furthermore, this invention helps enhance the safety of wind turbines and prevent structural failures such as potential fractures of the tower and moorings. It can also significantly improve the speed of design iteration and optimization, thereby shortening the project implementation cycle. In summary, this invention provides strong technical support for the design, optimization, and maintenance of wind turbines, achieving cost-effectiveness improvements in the design optimization of floating wind turbine systems.

[0150] Throughout this specification, the reference to "an embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout this specification do not necessarily all refer to the same embodiment, but may refer to the same embodiment. Furthermore, in one or more embodiments, as will be apparent to those skilled in the art from this disclosure, particular features, structures, or characteristics may be combined in any suitable manner.

[0151] As used herein, a module refers to any combination of hardware, software, and / or firmware. As an example, a module includes hardware such as a microcontroller associated with a non-transient medium for storing code suitable for execution by that microcontroller. Therefore, in one implementation, a reference to a module refers to hardware specifically configured to recognize and / or execute code to be stored on a non-transient medium. In another implementation, the use of "module" refers to a non-transient medium containing code specifically adapted for execution by a microcontroller to perform a predetermined operation. And, as can be inferred, in yet another implementation, the term "module" may refer to a combination of a microcontroller and a non-transient medium. Typically, the boundaries of modules illustrated as separate can vary and potentially overlap. For example, a first module and a second module may share hardware, software, firmware, or a combination thereof, while potentially retaining some independent hardware, software, or firmware.

[0152] Certain portions of the embodiments may be provided as a computer program product, which may include a computer-readable medium on which computer program instructions are stored, which can be used to program a computer (or other electronic device) to be executed by one or more processors to perform processes according to certain embodiments. The computer-readable medium may include, but is not limited to, a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic card or optical card, flash memory, or other types of computer-readable media suitable for storing electronic instructions. Furthermore, the embodiments may also be downloadable as a computer program product, wherein the program can be transferred from a remote computer to a requesting computer. In some embodiments, a non-transient computer-readable storage medium has data stored thereon representing a sequence of instructions that, when executed by a processor, cause the processor to perform certain operations.

[0153] It will be apparent to those skilled in the art that various modifications and variations can be made to the exemplary embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, it is intended that the invention cover modifications and variations falling within the scope of the appended claims and their equivalents.

Claims

1. An integrated modeling method for floating wind turbines, comprising: Obtaining an initial model of the floating wind turbine, which includes an upper turbine system, a tower, a floating platform, and a mooring system, wherein obtaining the initial model of the floating wind turbine includes: Obtain the structural parameters and material properties of the floating wind turbine; Based on the structural parameters and material properties of the upper fan system, rigid modeling and aerodynamic modeling are performed on the upper fan system to determine the initial model of the upper fan system; Based on the structural parameters and material properties of the floating platform, rigid or elastic modeling and hydrodynamic modeling are performed on the floating platform to determine the initial model of the floating platform; Based on the structural parameters and material properties of the mooring system, a rigid modeling of the mooring system is performed to determine the initial model of the mooring system; and Based on the structural parameters and material properties of the tower, a flexible modeling process is performed on the tower to determine its initial model; and Converting the initial model of the floating wind turbine into an integrated model of the floating wind turbine includes: The initial model coordinates of the upper wind turbine system are transformed to the coordinate system of the tower to form the upper wind turbine system part of the integrated model; The initial model coordinates of the floating platform are transformed to the coordinate system of the tower to form the model of the floating platform portion in the integrated model; Transform the initial model coordinates of the mooring system to the coordinate system of the tower to form the model of the mooring system portion of the integrated model; and The integrated model is constructed based on the converted models of the upper wind turbine system, floating platform, and mooring system, as well as the initial model of the tower.

2. The method as described in claim 1, characterized in that, The initial model of the upper wind turbine system includes at least one of the following: upper wind turbine system mass matrix, wind turbine aerodynamic added mass, and wind turbine aerodynamic damping. The initial model of the floating platform includes at least one of the following: the floating platform mass matrix, the floating platform hydrodynamic added mass, the floating platform potential flow damping, the floating platform hydrodynamic viscous damping, and the floating platform hydrostatic restoring force stiffness matrix. The initial model of the mooring system includes the restoring force stiffness matrix of the mooring system; and The initial model of the tower includes at least one of the following: tower mass matrix, tower structural damping, and tower stiffness matrix.

3. The method as described in claim 2, characterized in that, The integrated model includes at least one of a global mass matrix, a global damping matrix, and a global stiffness matrix. The global mass matrix is ​​composed of the coordinate-transformed mass matrix of the upper wind turbine system, the coordinate-transformed aerodynamic mass of the wind turbine, the coordinate-transformed mass matrix of the floating platform, the coordinate-transformed hydrodynamic mass of the floating platform, and the tower mass matrix. The global damping matrix is ​​composed of coordinate-transformed wind turbine aerodynamic damping, coordinate-transformed floating platform potential flow damping, coordinate-transformed floating platform hydrodynamic viscous damping, and the tower structure damping; and The global stiffness matrix is ​​composed of the coordinate-transformed still water restoring force stiffness matrix of the floating platform, the coordinate-transformed restoring force stiffness matrix of the mooring system, and the tower stiffness matrix.

4. The method as described in claim 3, characterized in that, The global mass matrix, the global damping matrix, and the global stiffness matrix are as follows: [M]=[M s ]+[M r ][T2]+[M P ][T1]+[A p ][T1]+[A r ][T2] [C]=[C s ]+[C p ][T1]+[C r ][T2]+[C v ][T1] [K]=[K s ]+[K p ][T1]+[K m ][T1] Where M, C, and K are the global mass matrix, the global damping matrix, and the global stiffness matrix, respectively. s M r , and M P These are the tower mass matrix, the upper wind turbine system mass matrix, and the floating platform mass matrix, respectively; A p and A r These are the hydrodynamic added mass of the floating platform and the aerodynamic added mass of the wind turbine, respectively; C s C p C r and C v These are, respectively, tower structure damping, floating platform potential flow damping, wind turbine aerodynamic damping, and floating platform hydrodynamic viscous damping; K s ,K p and K m These are the tower stiffness matrix, the floating platform still water restoring force stiffness matrix, and the mooring system restoring force stiffness matrix, respectively; T1 and T2 are the first coordinate transformation matrix and the second coordinate transformation matrix, respectively.

5. The method as described in claim 1, characterized in that, Aerodynamic modeling of the upper fan system includes: Calculate the aerodynamic added mass A of the wind turbine r The global calculation matrix and the wind turbine aerodynamic damping C r The global computation matrix, Where N represents the number of tower units, and N+1 represents the N+1 nodes in the global computation matrix. During the torque regulation phase, the following formula is used for calculation: During the blade pitch adjustment phase, the following formula is used for calculation: Where ω represents the frequency of the reciprocating motion; β represents the paddle pitch angle; T V T Ω T β Q v Q Ω Q β Let I represent the first-order partial derivatives of aerodynamic thrust and aerodynamic torque with respect to incident wind speed, rotor speed, and blade angle, respectively; d N represents the moment of inertia of the low-speed drive shaft. g Indicates the gear ratio; τ Ω K represents the partial derivative of the generator torque with respect to the wind turbine speed. p and K i These are the proportional gain coefficient and the integral gain coefficient, respectively.

6. The method as described in claim 1, characterized in that, Also includes: Aerodynamic modeling is performed on the upper wind turbine system and the tower to determine the aerodynamic loads on the upper structure; Hydrodynamic modeling is performed on the floating platform and the mooring system to determine the hydrodynamic loads on the substructure; as well as The equations of motion for the floating wind turbine are constructed based on the integrated model, the aerodynamic loads of the upper structure, and the hydrodynamic loads of the lower structure.

7. The method as described in claim 6, characterized in that, The equation of motion is: Where M, C, and K are the global mass matrix, global damping matrix, and global stiffness matrix of the integrated model, respectively, and δ is the displacement of the floating wind turbine. Let δ be the first derivative of displacement with respect to time. F is the second derivative of displacement δ with respect to time. aero and F hydro The aerodynamic loads on the upper structure and the hydrodynamic loads on the lower structure are respectively considered. A Fourier transform is performed on the equations of motion to obtain frequency-dependent equations of motion, which are: Where ω is the operating frequency of the floating fan, and i is the imaginary unit. Let δ be the displacement δ of the floating fan in the frequency domain. This represents the aerodynamic load of the superstructure in the frequency domain. This represents the hydrodynamic load of the substructure in the frequency domain.

8. An integrated modeling system for floating wind turbines, comprising: An initial model acquisition module is used to acquire an initial model of the floating wind turbine, which includes an upper turbine system, a tower, a floating platform, and a mooring system. The initial model acquisition module acquires the initial model of the floating wind turbine by: Obtain the structural parameters and material properties of the floating wind turbine; Based on the structural parameters and material properties of the upper fan system, rigid modeling and aerodynamic modeling are performed on the upper fan system to determine the initial model of the upper fan system; Based on the structural parameters and material properties of the floating platform, rigid or elastic modeling and hydrodynamic modeling are performed on the floating platform to determine the initial model of the floating platform; Based on the structural parameters and material properties of the mooring system, a rigid modeling of the mooring system is performed to determine the initial model of the mooring system; and Based on the structural parameters and material properties of the tower, a flexible modeling process is performed on the tower to determine its initial model; and An integrated model building module is used to convert the initial model of the floating wind turbine into an integrated model of the floating wind turbine, including the following: The initial model coordinates of the upper wind turbine system are transformed to the coordinate system of the tower to form the upper wind turbine system part of the integrated model; The initial model coordinates of the floating platform are transformed to the coordinate system of the tower to form the model of the floating platform portion in the integrated model; Transform the initial model coordinates of the mooring system to the coordinate system of the tower to form the model of the mooring system portion of the integrated model; and The integrated model is constructed based on the converted models of the upper wind turbine system, floating platform, and mooring system, as well as the initial model of the tower.

9. A computer-readable storage medium comprising code that, when executed, causes a computer to perform the method as claimed in any one of claims 1-7.

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