Dynamic thrust reduction method and device for wind turbine load suppression

Abstract

This application relates to the field of wind power generation technology, and particularly to a dynamic thrust reduction method and apparatus for wind turbine load suppression. The method includes: estimating the rotor thrust of the target wind turbine using the out-of-plane bending moment at the blade root; estimating the equivalent arm of the rotor of the target wind turbine based on the out-of-plane bending moment at the blade root and the rotor thrust; and generating a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine, thereby reducing the load on the target wind turbine to the target load corresponding to the target rotor thrust. This application can construct the relationship between the unmeasurable rotor thrust and the measurable out-of-plane bending moment at the blade root using the equivalent arm with only three tuned control parameters, thus achieving thrust reduction more directly. This application significantly improves the flexibility of use while effectively reducing the complexity of control parameter adjustment.

Description

Technical Field

[0001] This application relates to the field of wind power generation technology, and in particular to a dynamic thrust reduction method and apparatus for wind turbine load suppression. Background Technology

[0002] In recent years, the unit capacity of wind turbines has been growing rapidly. For industrial applications, wind power giants are now able to manufacture wind turbines of 20MW or even larger. To reduce costs, the mechanical components of large wind turbines are mainly made of lightweight, flexible materials. This can lead to potential vibrations in the mechanical components, and fatigue loads have become a concern. Studies have shown that when wind turbines operate near their rated wind speeds, the rotor experiences the greatest thrust, which has a significant impact on the loads at the blade roots and tower roots, potentially causing damage to flexible components.

[0003] In related technologies, load reduction is mainly achieved by limiting rotor thrust. Existing thrust reduction algorithms limit peak thrust by introducing a minimum pitch angle scheduling table.

[0004] However, adjusting the controller parameters in related technologies is time-consuming and laborious, requiring extensive static simulations to achieve the optimization goal and exhibiting low flexibility. The pitch angle scheduling table is difficult to modify based on real-time operating conditions, and the limitations of sensors, which can only detect blade root bending moments and cannot measure rotor thrust, make it impossible to form a closed loop of rotor thrust to formulate a closed-loop control strategy. Dynamic thrust reduction is difficult to achieve and urgently needs to be addressed. Summary of the Invention

[0005] This application provides a dynamic thrust reduction method and apparatus for wind turbine load suppression, which solves the problems in related technologies such as time-consuming and labor-intensive controller parameter adjustment, the need for a large number of static simulations to finally achieve the optimization goal and low flexibility, difficulty in modifying the pitch angle scheduling table according to real-time operation, and the limitation of sensors that can only detect blade root bending moment and cannot measure rotor thrust, thus making it impossible to form a closed loop of rotor thrust to formulate a closed-loop control strategy, and difficulty in realizing dynamic thrust reduction.

[0006] The first aspect of this application provides a dynamic thrust reduction method for wind turbine load suppression, comprising the following steps: estimating the rotor thrust of the target wind turbine by using the out-of-plane bending moment at the blade root of the target wind turbine; estimating the equivalent arm of the rotor of the target wind turbine based on the out-of-plane bending moment at the blade root and the rotor thrust; and generating a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust according to the equivalent arm and the actual rotor thrust of the target wind turbine, so as to reduce the load of the target wind turbine to the target load corresponding to the target rotor thrust.

[0007] Optionally, in one embodiment of this application, estimating the rotor thrust of the target wind turbine by means of the out-of-plane bending moment at the blade root of the target wind turbine includes: calculating the aerodynamic thrust and torque of the blade micro-element of the target wind turbine based on the blade element momentum strategy; calculating the aerodynamic thrust of the entire blade of the target wind turbine by means of the aerodynamic thrust and torque of the blade micro-element, so as to estimate the rotor thrust based on the aerodynamic thrust of the entire blade.

[0008] Optionally, in one embodiment of this application, generating a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine includes: determining the target blade pitch angle of the target wind turbine; and determining the rotor thrust command based on the target blade pitch angle.

[0009] Optionally, in one embodiment of this application, before generating a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine, the method further includes: calculating the actual out-of-plane bending moment at the blade root of the target wind turbine; and obtaining the actual rotor thrust using the actual out-of-plane bending moment at the blade root.

[0010] Optionally, in one embodiment of this application, the estimation expression for the rotor thrust is:

[0011]

[0012] Among them, F a,j N is the aerodynamic thrust of the entire blade. nodes r is the number of nodes in the leaf division. i v is the distance between the i-th leaf node and the leaf root. ∞ It is the inflow velocity, a i It is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, ρ is the air density, and dr is the local chord length. i The unit chord length.

[0013] Optionally, in one embodiment of this application, the estimation expression for the equivalent force arm is:

[0014]

[0015] Among them, L eq It is an equivalent arm, N nodes It is the number of nodes in the leaf division, v ∞ It is the inflow velocity, a iIt is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, r i It is the distance between the i-th leaf node and the leaf root.

[0016] A second aspect of this application provides a dynamic thrust reduction device for wind turbine load suppression, comprising: a first estimation module for estimating the rotor thrust of the target wind turbine by means of the out-of-plane bending moment at the blade root of the target wind turbine; a second estimation module for estimating the equivalent arm of the rotor of the target wind turbine based on the out-of-plane bending moment at the blade root and the rotor thrust; and a reduction module for generating a rotor thrust command to reduce the actual rotor thrust to a target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine, thereby reducing the load of the target wind turbine to a target load corresponding to the target rotor thrust.

[0017] Optionally, in one embodiment of this application, the first estimation module includes: a calculation unit, configured to calculate the aerodynamic thrust and torque of the blade micro-element of the target wind turbine based on the blade element momentum strategy; and an estimation unit, configured to calculate the aerodynamic thrust of the entire blade of the target wind turbine based on the aerodynamic thrust and torque of the blade micro-element, so as to estimate the rotor thrust based on the aerodynamic thrust of the entire blade.

[0018] Optionally, in one embodiment of this application, the reduction module includes: a first determining unit for determining the target blade pitch angle of the target wind turbine; and a second determining unit for determining the rotor thrust command based on the target blade pitch angle.

[0019] Optionally, in one embodiment of this application, it further includes: a first calculation module, used to calculate the actual out-of-plane bending moment at the blade root of the target wind turbine before generating a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine; and a second calculation module, used to obtain the actual rotor thrust using the actual out-of-plane bending moment at the blade root.

[0020] Optionally, in one embodiment of this application, the estimation expression for the rotor thrust can be:

[0021]

[0022] Among them, F a,j N is the aerodynamic thrust of the entire blade. nodes r is the number of nodes in the leaf division. iv is the distance between the i-th leaf node and the leaf root. ∞ It is the inflow velocity, a i It is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, ρ is the air density, and dr is the local chord length. i The unit chord length.

[0023] Optionally, in one embodiment of this application, the estimation expression for the equivalent force arm can be:

[0024]

[0025] Among them, L eq It is an equivalent arm, N nodes It is the number of nodes in the leaf division, v ∞ It is the inflow velocity, a i It is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, r i It is the distance between the i-th leaf node and the leaf root.

[0026] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the dynamic thrust reduction method for wind turbine load suppression as described in the above embodiments.

[0027] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described dynamic thrust reduction method for wind turbine load suppression.

[0028] A fifth aspect of this application provides a computer program product, including a computer program that, when executed, is used to implement the dynamic thrust reduction method for wind turbine load suppression as described above.

[0029] This application's embodiments can solve for rotor thrust and torque analytically based on simplified blade element momentum theory, and estimate the equivalent force arm accordingly. Then, an anti-saturation proportional-integral (PI) controller is used to determine the blade pitch angle, achieving dynamic thrust reduction for wind turbine load suppression. This allows for estimation of the actual rotor thrust of the wind turbine based on the out-of-plane bending moment at the blade root with only three tuned control parameters. The equivalent force arm is then used to construct the relationship between the unmeasurable rotor thrust and the measurable out-of-plane bending moment at the blade root, enabling more direct thrust reduction. The wide range of available parameters ensures control effectiveness over a broad range, and the rotor thrust command value can be specified according to actual needs, greatly improving the flexibility of this application and reducing the complexity of control parameter adjustment. This solves the problems in related technologies, such as time-consuming and laborious controller parameter adjustment, the need for extensive static simulations to achieve optimization goals with low flexibility, difficulty in modifying the pitch angle scheduling table based on real-time operation, and the limitation of sensors that can only detect blade root bending moment and cannot measure rotor thrust, thus preventing the formation of a closed loop for rotor thrust to formulate a closed-loop control strategy, and the difficulty in achieving dynamic thrust reduction.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. Attached Figure Description

[0031] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0032] Figure 1 This is a schematic diagram of the control framework of a dynamic thrust reduction method according to an embodiment of this application;

[0033] Figure 2 This is a flowchart of a dynamic thrust reduction method for wind turbine load suppression according to an embodiment of this application;

[0034] Figure 3 This is a schematic diagram of the dynamic thrust reduction device for wind turbine load suppression provided in the embodiments of this application;

[0035] Figure 4 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application.

[0036] Figure label:

[0037] 10-Dynamic thrust reduction device for wind turbine load suppression: 100-First estimation module, 200-Second estimation module and 300-Reduction module; 401-Memory, 402-Processor and 403-Communication interface. Detailed Implementation

[0038] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0039] The following description, with reference to the accompanying drawings, describes a dynamic thrust reduction method and apparatus for wind turbine load suppression according to embodiments of this application. Addressing the issues raised in the background section regarding the time-consuming and labor-intensive controller parameter adjustments, the need for extensive static simulations to achieve optimization goals, low flexibility, difficulty in modifying pitch angle scheduling tables based on real-time operating conditions, and the limitation of sensors (which can only detect blade root bending moments and cannot measure rotor thrust, thus hindering the formation of a closed-loop rotor thrust control strategy and making dynamic thrust reduction difficult), this application provides a dynamic thrust reduction method for wind turbine load suppression. In this method, rotor thrust and torque can be analytically solved based on simplified blade element momentum theory, and the equivalent force arm can be estimated accordingly. Then, an anti-saturation proportional-integral (PI) controller is used to determine the blade pitch angle, thereby achieving dynamic thrust reduction for wind turbine load suppression. This allows for the estimation of the actual rotor thrust of the wind turbine based on the out-of-plane bending moment at the blade root, requiring only three tuned control parameters. Then, by using equivalent force arms, the relationship between the unmeasurable rotor thrust and the measurable out-of-plane bending moment at the blade root is constructed, enabling more direct thrust reduction. The wide range of available parameters ensures control effectiveness over a broad range, and the rotor thrust command value can be specified according to actual needs, greatly improving the flexibility of this application and reducing the complexity of control parameter adjustment. This solves the problems in related technologies, such as time-consuming and laborious controller parameter adjustment, the need for extensive static simulations to achieve optimization goals with low flexibility, difficulty in modifying the pitch angle scheduling table based on real-time operating conditions, and the limitation of sensors that can only detect blade root bending moment and cannot measure rotor thrust, thus preventing the formation of a closed loop for rotor thrust to formulate a closed-loop control strategy, and the difficulty in achieving dynamic thrust reduction.

[0040] Before explaining the dynamic thrust reduction method for wind turbine load suppression in the embodiments of this application, the control framework of the dynamic thrust reduction method in the embodiments of this application will be explained first. Figure 1 This is a schematic diagram of the control framework of a dynamic thrust reduction method according to an embodiment of this application, as shown below. Figure 1 As shown:

[0041] in, This is the aerodynamic thrust reference value. This is an estimated value for aerodynamic thrust. It is a proportional control coefficient. It is a proportional control coefficient. It is the pitch angle command value output by the PI controller, β DPS It is the final output pitch angle command value of the anti-saturation PI controller, β. GSPI It is a unified pitch controller command value.

[0042] Specifically, Figure 2 This is a flowchart of a dynamic thrust reduction method for wind turbine load suppression provided in an embodiment of this application.

[0043] like Figure 2 As shown, the dynamic thrust reduction method for wind turbine load suppression includes the following steps:

[0044] In step S201, the rotor thrust of the target wind turbine is estimated using the out-of-plane bending moment at the blade root of the target wind turbine. The expression for estimating the rotor thrust can be:

[0045]

[0046] Among them, F a,j N is the aerodynamic thrust of the entire blade. nodes r is the number of nodes in the leaf division. i v is the distance between the i-th leaf node and the leaf root. ∞ It is the inflow velocity, a i It is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, ρ is the air density, and dr is the local chord length. i The unit chord length.

[0047] Those skilled in the art will understand that measuring the rotor thrust of a wind turbine plays a significant role in achieving dynamic thrust reduction. If the rotor thrust of the wind turbine can be measured, thrust reduction can be achieved more directly. Dynamic thrust reduction through wind turbine load suppression can be understood here as improving the reliability and service life of the turbine by reducing the dynamic load it bears during operation. Specifically, dynamic thrust reduction refers to reducing the changes in thrust before and after the rotor caused by factors such as wind speed variations during wind turbine operation, thereby reducing the dynamic load on the turbine, extending its service life, and reducing failures and maintenance costs caused by excessive load.

[0048] However, due to sensor limitations, wind turbine measurement equipment can only detect out-of-plane flapping and in-plane shimmy moments at the blade root. Rotor thrust cannot be measured, therefore a closed-loop control strategy cannot be directly formulated based on rotor thrust.

[0049] Based on this, when achieving dynamic thrust reduction to suppress wind turbine loads, the embodiments of this application can first estimate the rotor thrust of the target wind turbine based on the out-of-plane bending moment at the blade root of the target wind turbine, so as to achieve dynamic thrust reduction of the target wind turbine. Here, the target wind turbine can be understood as the wind turbine for which dynamic thrust reduction is desired.

[0050] The expression for estimating rotor thrust can be, but is not limited to, expressed as:

[0051]

[0052] Among them, F a,j N is the aerodynamic thrust of the entire blade. nodes r is the number of nodes in the leaf division. i v is the distance between the i-th leaf node and the leaf root. ∞ It is the inflow velocity, a i It is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, ρ is the air density, and dr is the local chord length. i The unit chord length.

[0053] The out-of-plane bending moment at the blade root in this embodiment, also known as the blade root flapping moment, refers to an important type of bending moment experienced by the root of a wind turbine blade. Under wind force, a wind turbine blade generates a bending moment around its axis, primarily acting in the flapping direction. The flapping moment is mainly generated by aerodynamic thrust and is a result of aerodynamic loads acting on the blade. When wind acts on the blade, it generates a force perpendicular to the blade plane, causing the blade to bend in the flapping direction, thus forming a flapping moment.

[0054] The following is a further explanation of the process of estimating the rotor thrust of the target wind turbine by using the out-of-plane bending moment at the blade root of the target wind turbine in the embodiments of this application.

[0055] Optionally, in one embodiment of this application, estimating the rotor thrust of the target wind turbine by the out-of-plane bending moment at the blade root of the target wind turbine includes: calculating the aerodynamic thrust and torque of the blade micro-element of the target wind turbine based on the blade element momentum strategy; calculating the aerodynamic thrust of the entire blade of the target wind turbine by the aerodynamic thrust and torque of the blade micro-element, so as to estimate the rotor thrust based on the aerodynamic thrust of the entire blade.

[0056] In practical application, when estimating the rotor thrust of a target wind turbine by the out-of-plane bending moment at the blade root, this application can be based on blade element momentum theory. Blade element momentum theory is one of the main methods for wind turbine blade design and aerodynamic performance calculation; it combines blade element theory and momentum theory. Simply put, blade element momentum theory can be understood as dividing the blade radially into several infinitely thin blade units, called "blade elements." When air flows over a blade element, a pressure difference is formed on its surface. This pressure difference generates a change in the momentum of the airflow entering and exiting the blade element, thereby driving the rotor to rotate and do work. The specific process can be represented as follows:

[0057] First, based on the leaf element momentum theory, the following expression can be obtained:

[0058]

[0059] Among them, C p and C t These are the power coefficient and thrust coefficient, and 'a' is the axial induction factor.

[0060] At a certain radial position (denoted as i), the inflow velocity triangle and angle of the blade profile are defined as shown in the figure. The inflow resultant velocity v i The angle between the rotor and the plane of rotation is defined as the inflow angle φ. i The angle between the inflow angle and the profile chord is defined as the local angle of attack α. i The angle between the section chord and the rotor's plane of rotation is defined as the local pitch angle β. i The relationship between the above three perspectives can be expressed as:

[0061]

[0062] Where, β twist,i β is the local twist angle, and β is the propeller pitch angle.

[0063] Based on geometric relationships, the following expression can be obtained:

[0064]

[0065] Among them, v ∞ It is the inflow velocity, r iIt is the distance between the i-th leaf node and the leaf root. It is a local tangential inducing factor. i It is a local axial inducing factor, Ω r It refers to the rotational speed of the wind turbine.

[0066] It should be noted that the axial induction factor and the tangential induction factor are not independent, and are determined by a. i and The determined direction of the combined induced velocity is parallel to and opposite to the direction of the lift force of the blade element, which can be expressed as follows:

[0067]

[0068] in,

[0069]

[0070] Eliminate φ i We can obtain the following expression:

[0071]

[0072] Solving the above equation and selecting positive solutions, we obtain the following expression:

[0073]

[0074] Taking a ring-shaped flow tube element with a radial height of dr on the blade as an example, according to the theorems of axial and tangential angular momentum, the thrust F acting on the blade element is... a,i Torque T a,i and power P a,i They can be represented as:

[0075]

[0076] also,

[0077]

[0078] Among them, C l,i It is the lift coefficient, C d,i It is the drag coefficient, C n,i It is the normal force coefficient, C t,i It is the tangential force coefficient.

[0079] The thrust and torque on the blade element can also be described by the blade element theory as follows:

[0080]

[0081] Where, n b It refers to the number of leaves, c i It is the local chord length, Wi The inflow velocity can be expressed as follows:

[0082]

[0083] According to blade element momentum theory, the rotor of a wind turbine can be considered as an actuated disk composed of a series of concentric annular flow tubes, assuming that these flow tubes do not affect each other. Based on this, the local aerodynamic power for the i-th ring can be expressed as:

[0084]

[0085] Additionally, local aerodynamic power can also be calculated in another form, as follows:

[0086]

[0087] Solving the above two equations simultaneously, we obtain the following expression:

[0088]

[0089] 14. Combining (6) and (14), we can obtain the following expression:

[0090]

[0091] For the sake of brevity, the embodiments of this application may be referred to as

[0092]

[0093] After sorting, we can obtain:

[0094]

[0095] It should be noted that this is a quartic equation in one variable. Because a quartic equation in one variable has an analytical solution, 'a' can be calculated analytically. i .

[0096] Therefore, the aerodynamic thrust of the entire blade can be calculated from the local aerodynamic thrust, and the formula can be expressed as follows:

[0097]

[0098] Where, N nodes It is the number of nodes in the leaf division.

[0099] Step S202: Based on the out-of-plane bending moment at the blade root and the rotor thrust, estimate the equivalent arm of the rotor of the target wind turbine.

[0100] The estimation expression for the equivalent force arm can be:

[0101]

[0102] Among them, L eq It is an equivalent arm, N nodes It is the number of nodes in the leaf division, v ∞ It is the inflow velocity, a i It is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, r i It is the distance between the i-th leaf node and the leaf root.

[0103] It is understandable that during the rotation of a wind turbine rotor, the wind force acting on the blades generates a torque, which can be considered as being generated by an equivalent force acting on an equivalent lever arm. In the embodiments of this application, the "equivalent lever arm" can be understood as a virtual parameter used to describe the effect of rotor rotation.

[0104] As one possible approach, embodiments of this application can use an equivalent force arm to construct the relationship between the unmeasurable rotor thrust and the measurable out-of-plane moment at the blade root. Following the calculation process of the target wind turbine in the previous embodiments, the calculation process of the equivalent force arm can be expressed as follows:

[0105] Expanding (18) yields:

[0106]

[0107] Similarly, the formula for calculating the out-of-plane bending moment at the blade root can be expressed as follows:

[0108]

[0109] In the embodiments of this application, the lift and drag acting on each blade node can be equivalent to a resultant force and torque, having an equivalent force arm L. eq , can be represented as follows:

[0110] M yc,j =F a,j ·L eq (twenty one)

[0111] Substituting (19) and (20) yields the equivalent force arm L. eq2 The expression is as follows:

[0112]

[0113] The embodiments of this application can use a rotor thrust estimation method based on the simplified blade element momentum theory to solve for rotor thrust and torque analytically, and estimate the equivalent arm accordingly. This allows for dynamic thrust reduction of the wind turbine load based on the equivalent arm and rotor thrust.

[0114] Step S203: Generate a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the actual rotor thrust of the equivalent arm and the target wind turbine, so as to reduce the load of the target wind turbine to the target load corresponding to the target rotor thrust.

[0115] As one possible approach, after calculating the equivalent arm of the wind turbine rotor, in practical applications, the embodiments of this application can generate a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the combination of the equivalent arm and the actual rotor thrust of the target wind turbine. The load of the target wind turbine can then be reduced to a target load using a controller such as an anti-saturation PI controller.

[0116] Here, the target rotor thrust can be understood as the desired rotor thrust value or range that the target wind turbine unit is expected to achieve. The target load can be understood as the load on the target wind turbine unit reduced to a certain wind speed after the rotor thrust is reduced. The anti-saturation proportional-integral controller can be represented as follows:

[0117]

[0118] in, It is the aerodynamic thrust command value. It is an estimated value of aerodynamic thrust. and These are the proportional and integral coefficients, respectively. β min It is the minimum pitch angle. It is the pitch angle output of the dynamic thrust reduction method. It is the integrator input.

[0119] The embodiments of this application can calculate and combine the equivalent arm and the actual rotor thrust to achieve dynamic thrust reduction for target wind turbine load suppression. While simplifying operation, it can effectively improve the efficiency of dynamic thrust reduction.

[0120] Optionally, in one embodiment of this application, generating a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine includes: determining the target blade pitch angle of the target wind turbine; and determining the rotor thrust command based on the target blade pitch angle.

[0121] It is understood that an anti-saturation PI controller is a control algorithm that can accurately track target values ​​while ensuring the stability of the target wind turbine system. In this embodiment, the anti-saturation PI controller can be used to determine the target blade pitch angle of the target wind turbine based on the estimated equivalent force arm and the actual required rotor thrust command value. The target blade pitch angle can be understood as the blade pitch angle corresponding to when the target wind turbine reduces its dynamic thrust to a certain target rotor thrust.

[0122] In other embodiments, this application may employ an anti-saturation proportional-integral (PI) controller to determine the target blade pitch angle. This allows for the determination of the rotor thrust command during dynamic thrust reduction based on the target blade pitch angle. In other words, by adjusting the blade pitch angle, the aerodynamic forces and moments on the blades can be altered, thereby achieving dynamic reduction of rotor thrust.

[0123] Optionally, in one embodiment of this application, before generating the rotor thrust command based on the equivalent arm and the actual rotor thrust of the target wind turbine, the method further includes: calculating the actual out-of-plane bending moment at the blade root of the target wind turbine; and obtaining the actual rotor thrust using the actual out-of-plane bending moment at the blade root.

[0124] In actual implementation, before determining the blade pitch angle through the anti-saturation proportional-integral (PI) controller to reduce rotor thrust to the target rotor thrust, it is also necessary to calculate the actual rotor thrust of the target wind turbine to determine the rotor thrust command value actually required by the target wind turbine at the current time. The actual rotor thrust is calculated in the same way as the rotor thrust calculation steps mentioned above, and can be estimated from the actual out-of-plane bending moment at the blade root.

[0125] In practical applications, the embodiments of this application can estimate the actual rotor thrust of a target wind turbine based on the actual out-of-plane bending moment at the blade root of the wind turbine. Since the flapping moment in the out-of-plane direction at the blade root can be detected by measuring equipment such as wind turbines, the actual rotor thrust of the target wind turbine can be measured. This allows for more direct dynamic thrust reduction of the target wind turbine and flexible adjustment of the rotor thrust command value to achieve optimized operation of the wind turbine.

[0126] The dynamic thrust reduction method for wind turbine load suppression proposed in this application can solve for rotor thrust and torque analytically based on simplified blade element momentum theory, and estimate the equivalent force arm accordingly. Then, an anti-saturation proportional-integral (PI) controller is used to determine the blade pitch angle, thereby achieving dynamic thrust reduction for wind turbine load suppression. This allows for estimation of the actual rotor thrust of the wind turbine based on the out-of-plane bending moment at the blade root with only three tuned control parameters. The relationship between the unmeasurable rotor thrust and the measurable out-of-plane moment at the blade root is then constructed using the equivalent force arm, enabling more direct thrust reduction. The wide range of available parameters ensures control effectiveness over a broad range, and the rotor thrust command value can be specified according to actual needs, greatly improving the flexibility of this application and reducing the complexity of control parameter adjustment. This solves the problems in related technologies, such as the time-consuming and laborious adjustment of controller parameters, the need for a large number of static simulations to finally achieve the optimization goal and the low flexibility, the difficulty in modifying the pitch angle scheduling table according to real-time operation, the limitation of sensors that can only detect blade root bending moment and cannot measure rotor thrust, thus making it impossible to form a closed loop of rotor thrust to formulate a closed-loop control strategy, and the difficulty in realizing dynamic thrust reduction.

[0127] Next, referring to the accompanying drawings, a dynamic thrust reduction device for wind turbine load suppression according to an embodiment of this application is described.

[0128] Figure 3 This is a schematic diagram of the dynamic thrust reduction device for wind turbine load suppression according to an embodiment of this application.

[0129] like Figure 3 As shown, the dynamic thrust reduction device 10 for wind turbine load suppression includes: a first estimation module 100, a second estimation module 200, and a reduction module 300.

[0130] The first estimation module 100 is used to estimate the rotor thrust of the target wind turbine by using the out-of-plane bending moment at the blade root of the target wind turbine.

[0131] The second estimation module 200 is used to estimate the equivalent arm of the rotor of the target wind turbine based on the out-of-plane bending moment at the blade root and the rotor thrust.

[0132] The reduction module 300 is used to generate a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the actual rotor thrust of the equivalent arm and the target wind turbine, so as to reduce the load of the target wind turbine to the target load corresponding to the target rotor thrust.

[0133] Optionally, in one embodiment of this application, the first estimation module 100 includes a calculation unit and an estimation unit.

[0134] The computing unit is used to calculate the aerodynamic thrust and torque of the blade micro-element of the target wind turbine based on the blade element momentum strategy.

[0135] The estimation unit is used to calculate the aerodynamic thrust of the entire blade of the target wind turbine through the aerodynamic thrust and torque of the blade micro-element, so as to estimate the rotor thrust based on the aerodynamic thrust of the entire blade.

[0136] Optionally, in one embodiment of this application, the reduction module 300 includes: a first determining unit and a second determining unit.

[0137] The first determining unit is used to determine the target blade pitch angle of the target wind turbine.

[0138] The second determining unit is used to determine the rotor thrust command based on the target blade pitch angle.

[0139] Optionally, in one embodiment of this application, it further includes: a first computing module and a second computing module.

[0140] The first calculation module is used to calculate the actual out-of-plane bending moment at the blade root of the target wind turbine before generating the rotor thrust command based on the equivalent arm and the actual rotor thrust of the target wind turbine.

[0141] The second calculation module is used to obtain the actual rotor thrust by utilizing the actual out-of-plane bending moment at the blade root.

[0142] Optionally, in one embodiment of this application, the estimation expression for rotor thrust can be:

[0143]

[0144] Among them, F a,j N is the aerodynamic thrust of the entire blade. nodes r is the number of nodes in the leaf division. i v is the distance between the i-th leaf node and the leaf root. ∞ It is the inflow velocity, a i It is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, ρ is the air density, and dr is the local chord length. i The unit chord length.

[0145] Optionally, in one embodiment of this application, the estimation expression for the equivalent force arm can be:

[0146]

[0147] Among them, Leq It is an equivalent arm, N nodes It is the number of nodes in the leaf division, v ∞ It is the inflow velocity, a i It is a local axial inducing factor, Ω r It is the wind turbine speed. It is a local tangential inducing factor, C n,i It is the normal force coefficient, c i It is the local chord length, r i It is the distance between the i-th leaf node and the leaf root.

[0148] It should be noted that the explanation of the above-mentioned embodiment of the dynamic thrust reduction method for wind turbine load suppression also applies to the dynamic thrust reduction device for wind turbine load suppression in this embodiment, and will not be repeated here.

[0149] The dynamic thrust reduction device for wind turbine load suppression proposed in this application can solve for rotor thrust and torque analytically based on simplified blade element momentum theory, and estimate the equivalent force arm accordingly. Then, an anti-saturation proportional-integral (PI) controller is used to determine the blade pitch angle, thereby achieving dynamic thrust reduction for wind turbine load suppression. This allows for estimation of the actual rotor thrust of the wind turbine based on the out-of-plane bending moment at the blade root with only three tuned control parameters. The relationship between the unmeasurable rotor thrust and the measurable out-of-plane moment at the blade root is then constructed using the equivalent force arm, enabling more direct thrust reduction. The wide range of available parameters ensures control effectiveness over a broad range, and the rotor thrust command value can be specified according to actual needs, greatly improving the flexibility of this application and reducing the complexity of control parameter adjustment. This solves the problems in related technologies, such as the time-consuming and laborious adjustment of controller parameters, the need for a large number of static simulations to finally achieve the optimization goal and the low flexibility, the difficulty in modifying the pitch angle scheduling table according to real-time operation, the limitation of sensors that can only detect blade root bending moment and cannot measure rotor thrust, thus making it impossible to form a closed loop of rotor thrust to formulate a closed-loop control strategy, and the difficulty in realizing dynamic thrust reduction.

[0150] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include:

[0151] The memory 401, the processor 402, and the computer program stored on the memory 401 and capable of running on the processor 402.

[0152] When the processor 402 executes the program, it implements the dynamic thrust reduction method for wind turbine load suppression provided in the above embodiments.

[0153] Furthermore, electronic devices also include:

[0154] Communication interface 403 is used for communication between memory 401 and processor 402.

[0155] The memory 401 is used to store computer programs that can run on the processor 402.

[0156] The memory 401 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0157] If the memory 401, processor 402, and communication interface 403 are implemented independently, then the communication interface 403, memory 401, and processor 402 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be divided into address buses, data buses, control buses, etc. For ease of representation, Figure 4 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0158] Optionally, in a specific implementation, if the memory 401, processor 402, and communication interface 403 are integrated on a single chip, then the memory 401, processor 402, and communication interface 403 can communicate with each other through an internal interface.

[0159] Processor 402 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0160] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described dynamic thrust reduction method for wind turbine load suppression.

[0161] This application also provides a computer program product, including a computer program that can run computer instructions. When the computer instructions are executed by a processor, they implement the dynamic thrust reduction method for wind turbine load suppression provided in this application.

[0162] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0163] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0164] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing a custom logical function or process step, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed in a different order than shown or discussed, including performing functions in a substantially simultaneous manner or in a reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application pertain.

[0165] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0166] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0167] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0168] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0169] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A dynamic thrust reduction method for wind turbine load suppression, characterized in that, Includes the following steps: The rotor thrust of the target wind turbine is estimated by the out-of-plane bending moment at the blade root of the target wind turbine. Based on the out-of-plane bending moment at the blade root and the rotor thrust, the equivalent arm of the rotor of the target wind turbine is estimated, wherein the equivalent arm is a virtual parameter used to describe the rotor rotation effect. Based on the equivalent arm and the actual rotor thrust of the target wind turbine, a rotor thrust command is generated to reduce the actual rotor thrust to the target rotor thrust, so as to reduce the load of the target wind turbine to the target load corresponding to the target rotor thrust; The step of generating a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine includes: determining the target blade pitch angle of the target wind turbine; and determining the rotor thrust command based on the target blade pitch angle. The estimation expression for the equivalent force arm is as follows: ， in, It is the equivalent force arm mentioned above. It is the number of nodes in the leaf division. It is the inflow rate. It is a local axial inducing factor. It is the wind turbine speed. It is a local tangential inducing factor. It is the normal force coefficient. It is the local chord length. It is the first The distance between each leaf node and the leaf root.

2. The method according to claim 1, characterized in that, The estimation of the rotor thrust of the target wind turbine by using the out-of-plane bending moment at the blade root of the target wind turbine includes: Based on the blade element momentum strategy, the aerodynamic thrust and torque of the blade micro-element of the target wind turbine are calculated. The aerodynamic thrust of the entire blade of the target wind turbine is calculated using the aerodynamic thrust and torque of the blade micro-element, so as to estimate the rotor thrust based on the aerodynamic thrust of the entire blade.

3. The method according to claim 1, characterized in that, Before generating a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine, the method further includes: Calculate the actual out-of-plane bending moment at the blade root of the target wind turbine; The actual rotor thrust is obtained by using the out-of-plane bending moment at the root of the actual blade.

4. The method according to claim 2, characterized in that, The estimation expression for the rotor thrust is: ， in, This refers to the aerodynamic thrust of the entire blade. It is the number of nodes in the leaf division. It is The distance between each leaf node and the leaf root It is the inflow rate. It is a local axial inducing factor. It is the wind turbine speed. It is a local tangential inducing factor. It is the normal force coefficient. It is the local chord length. air density, The unit chord length.

5. A dynamic thrust reduction device for wind turbine load suppression, characterized in that, include: The first estimation module is used to estimate the rotor thrust of the target wind turbine by the out-of-plane bending moment at the blade root of the target wind turbine. The second estimation module is used to estimate the equivalent arm of the rotor of the target wind turbine based on the out-of-plane bending moment at the blade root and the rotor thrust, wherein the equivalent arm is a virtual parameter used to describe the rotor rotation effect. The reduction module is used to generate a rotor thrust command to reduce the actual rotor thrust to the target rotor thrust based on the equivalent arm and the actual rotor thrust of the target wind turbine, so as to reduce the load of the target wind turbine to the target load corresponding to the target rotor thrust. The reduction module includes: a first determining unit for determining the target blade pitch angle of the target wind turbine; and a second determining unit for determining the rotor thrust command based on the target blade pitch angle. The estimation expression for the equivalent force arm is as follows: ， in, It is the equivalent arm mentioned above. It is the number of nodes in the leaf division. It is the inflow rate. It is a local axial inducing factor. It is the wind turbine speed. It is a local tangential inducing factor. It is the normal force coefficient. It is the local chord length. It is The distance between each leaf node and the leaf root.

6. An electronic device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, the processor executing the program to implement the dynamic thrust reduction method for wind turbine load suppression as described in any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the dynamic thrust reduction method for wind turbine load suppression as described in any one of claims 1-4.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed, it is used to implement the dynamic thrust reduction method for wind turbine load suppression as described in any one of claims 1-4.

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