Dynamic thrust reduction method and device for load suppression of wind turbine generator

Abstract

The invention relates to the technical field of wind power generation, in particular to a dynamic thrust reduction method and device for wind turbine generator load suppression, and the method comprises the steps: estimating the rotor thrust of a target wind turbine generator through the blade root out-of-plane bending moment of the target wind turbine generator; estimating an equivalent force arm of a rotor of the target wind turbine generator based on the blade root out-of-plane bending moment and the rotor thrust; and a rotor thrust instruction for reducing the actual rotor thrust to the target rotor thrust is generated according to the equivalent force arm and the actual rotor thrust of the target wind turbine generator, so that the load of the target wind turbine generator is reduced to the target load corresponding to the target rotor thrust. According to the method, the relation between the unmeasurable rotor thrust and the measurable blade root out-of-plane torque can be constructed through the equivalent force arm under the condition that only three set control parameters are needed, so that thrust reduction can be achieved more directly, the use flexibility is greatly improved, and meanwhile, the application range is widened. And the complexity of control parameter adjustment is effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of wind power generation, and in particular to a method and device for dynamic thrust reduction of wind turbine load suppression. Background Art

[0002] The unit capacity of wind turbines has been growing rapidly in recent years. For industrial applications, wind power giants are currently able to manufacture wind turbines of 20MW or even larger. In order to reduce costs, the mechanical components of large wind turbines are mainly made of lightweight flexible materials. This will cause potential vibration of mechanical components, and fatigue loads have also become a concern. Studies have shown that when wind turbines are running near the rated wind speed, the thrust on the rotor is the largest, which has a greater impact on the loads at the root of the blades and the root of the tower, and may cause damage to the flexible components.

[0003] In the related art, the load is mainly reduced by limiting the rotor thrust. The existing thrust reduction algorithm achieves the limitation of peak thrust by introducing a minimum pitch angle scheduling table.

[0004] However, the controller parameter adjustment in the related technology is time-consuming and labor-intensive, and a large amount of static simulation is required to finally achieve the optimization goal and has low flexibility. The pitch angle scheduling table is difficult to modify according to the real-time operating conditions, and the limitation of the sensor is that it can only detect the blade root bending moment and cannot measure the rotor thrust. Therefore, it is impossible to form a closed loop of the rotor thrust to formulate a closed-loop control strategy. Dynamic thrust reduction is difficult to achieve and needs to be solved urgently. Summary of the invention

[0005] The present application provides a method and device for dynamic thrust reduction with load suppression of a wind turbine set, so as to solve the problems in the related art that the adjustment of controller parameters is time-consuming and labor-intensive, a large number of static simulations are required to finally achieve the optimization goal and the flexibility is low, the pitch angle scheduling table is difficult to modify according to the real-time operating conditions, and the limitation of the sensor is that it can only detect the blade root bending moment and cannot measure the rotor thrust, so it is impossible to form a closed loop of the rotor thrust to formulate a closed-loop control strategy, and the dynamic thrust reduction is difficult to achieve.

[0006] A first aspect of the present application provides a dynamic thrust reduction method for load suppression of a wind turbine generator set, comprising the following steps: estimating the rotor thrust of a target wind turbine generator set by means of the out-of-plane bending moment of a blade root of the target wind turbine generator set; estimating the equivalent force arm of the rotor of the target wind turbine generator set based on the out-of-plane bending moment of the blade root and the rotor thrust; and generating a rotor thrust instruction for reducing the actual rotor thrust to a target rotor thrust according to the equivalent force arm and the actual rotor thrust of the target wind turbine generator set, so as to reduce the load of the target wind turbine generator set to a target load corresponding to the target rotor thrust.

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

[0008] Optionally, in one embodiment of the present application, generating a rotor thrust instruction for reducing the actual rotor thrust to a target rotor thrust based on the equivalent force arm and the actual rotor thrust of the target wind turbine group includes: determining a target blade pitch angle of the target wind turbine group; and determining the rotor thrust instruction based on the target blade pitch angle.

[0009] Optionally, in one embodiment of the present application, before generating a rotor thrust instruction for reducing the actual rotor thrust to a target rotor thrust based on the equivalent force arm and the actual rotor thrust of the target wind turbine group, it also includes: calculating an actual blade root out-of-plane bending moment of the target wind turbine group; and obtaining the actual rotor thrust using the actual blade root out-of-plane bending moment.

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

[0011]

[0012] Among them, F a,j is the aerodynamic thrust of the entire blade, N nodes is the number of nodes that the leaf is divided into, r i is the distance between the ith leaf node and the leaf root, v ∞ is the inflow velocity, a i is the local axial induction factor, Ω r is the wind wheel speed, is the local tangential induction factor, C n,i is the normal force coefficient, c i is the local chord length, ρ is the air density, dr i is the unit chord length.

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

[0014]

[0015] Among them, L eq is the equivalent force arm, N nodes is the number of nodes that the leaf is divided into, v ∞ is the inflow velocity, a iis the local axial induction factor, Ω r is the wind wheel speed, is the local tangential induction factor, C n,i is the normal force coefficient, c i is the local chord length, r i is the distance between the i-th leaf node and the leaf root.

[0016] A second aspect of the present application provides a dynamic thrust reduction device for load suppression of a wind turbine generator set, comprising: a first estimation module, used to estimate the rotor thrust of a target wind turbine generator set through the out-of-plane bending moment of the blade root of the target wind turbine generator set; a second estimation module, used to estimate the equivalent force arm of the rotor of the target wind turbine generator set based on the out-of-plane bending moment of the blade root and the rotor thrust; a reduction module, used to generate a rotor thrust instruction for reducing the actual rotor thrust to the target rotor thrust based on the equivalent force arm and the actual rotor thrust of the target wind turbine generator set, so as to reduce the load of the target wind turbine generator set to the target load corresponding to the target rotor thrust.

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

[0018] Optionally, in one embodiment of the present application, the curtailment module includes: a first determination unit, used to determine a target blade pitch angle of the target wind turbine; and a second determination unit, used to determine the rotor thrust instruction based on the target blade pitch angle.

[0019] Optionally, in one embodiment of the present application, it also includes: a first calculation module, used to calculate the actual blade root out-of-plane bending moment of the target wind turbine group before generating a rotor thrust instruction for reducing the actual rotor thrust to the target rotor thrust based on the equivalent force arm and the actual rotor thrust of the target wind turbine group; and a second calculation module, used to obtain the actual rotor thrust using the actual blade root out-of-plane bending moment.

[0020] Optionally, in one embodiment of the present application, the estimation expression of the rotor thrust may be:

[0021]

[0022] Among them, F a,j is the aerodynamic thrust of the entire blade, N nodes is the number of nodes that the leaf is divided into, r iis the distance between the ith leaf node and the leaf root, v ∞ is the inflow velocity, a i is the local axial induction factor, Ω r is the wind wheel speed, is the local tangential induction factor, C n,i is the normal force coefficient, c i is the local chord length, ρ is the air density, dr i is the unit chord length.

[0023] Optionally, in one embodiment of the present application, the estimation expression of the equivalent force arm may be:

[0024]

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

[0026] A third aspect of the present application provides an electronic device, comprising: 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 load suppression of a wind turbine as described in the above embodiment.

[0027] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned dynamic thrust reduction method for suppressing the load of a wind turbine.

[0028] A fifth aspect of the present application provides a computer program product, including a computer program, which, when executed, is used to implement the above-mentioned dynamic thrust reduction method for suppressing the load of a wind turbine.

[0029] The embodiment of the present application can solve the rotor thrust and torque by analytical solution based on the simplified blade element momentum theory, and estimate the equivalent force arm accordingly, and then use the anti-saturation proportional integral (PI) controller to determine the blade pitch angle, so as to achieve dynamic thrust reduction of wind turbine load suppression. Thus, it is realized that the actual rotor thrust of the wind turbine can be estimated according to the out-of-plane bending moment of the blade root under the condition of only three set control parameters, and then the relationship between the unmeasurable rotor thrust and the measurable out-of-plane moment of the blade root is constructed by the equivalent force arm, so that the thrust reduction can be achieved more directly, the wide range of available parameters can also ensure the control effect in a large range, and the rotor thrust command value can be specified according to actual needs, which greatly improves the flexibility of the application, and the complexity of control parameter adjustment is lower. Thus, the controller parameter adjustment in the related art is time-consuming and laborious, a large number of static simulations are required to finally achieve the optimization target and the flexibility is low, the pitch angle scheduling table is difficult to modify according to the real-time operation situation, and the sensor is limited to only detect the blade root bending moment and cannot measure the rotor thrust, so it is impossible to form a closed loop of the rotor thrust to formulate a closed-loop control strategy, and the dynamic thrust reduction is difficult to achieve.

[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 the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[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 A schematic diagram of a control framework of a dynamic thrust reduction method according to an embodiment of the present application;

[0033] Figure 2 A flow chart of a dynamic thrust reduction method for load suppression of a wind turbine set provided according to an embodiment of the present application;

[0034] Figure 3 It is a structural schematic diagram of a dynamic thrust reduction device for load suppression of a wind turbine set provided in an embodiment of the present application;

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

[0036] Reference numerals:

[0037] 10-Dynamic thrust reduction device for load suppression of wind turbine set: 100-first estimation module, 200-second estimation module and 300-reduction module; 401-memory, 402-processor and 403-communication interface. DETAILED DESCRIPTION

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

[0039] The following describes the dynamic thrust reduction method and device for load suppression of wind turbines according to the embodiment of the present application with reference to the accompanying drawings. In view of the fact that the adjustment of controller parameters in the related technologies mentioned in the above background technology is time-consuming and labor-intensive, a large number of static simulations are required to finally achieve the optimization goal and the flexibility is low, the pitch angle scheduling table is difficult to modify according to the real-time operation situation, and the limitation of the sensor is that it can only detect the blade root bending moment and cannot measure the rotor thrust, so it is impossible to form a closed loop of the rotor thrust to formulate a closed-loop control strategy, and the problem of difficulty in implementing dynamic thrust reduction, the present application provides a dynamic thrust reduction method for load suppression of wind turbines, in which the rotor thrust and torque can be solved by analytical solution based on the simplified blade element momentum theory, and the equivalent force arm can be estimated accordingly, and then the anti-saturation proportional integral (PI) controller is used to determine the blade pitch angle to achieve dynamic thrust reduction for load suppression of wind turbines. This makes it possible to estimate the actual rotor thrust of the wind turbine according to the out-of-plane bending moment of the blade root with only three set control parameters, and then to construct the relationship between the unmeasurable rotor thrust and the measurable out-of-plane moment of the blade root through the equivalent force arm, so that thrust reduction can be achieved more directly. The wide range of available parameters can also ensure the control effect in a large range, and the rotor thrust command value can be specified according to actual needs, which greatly improves the flexibility of use of the present application and reduces the complexity of control parameter adjustment. Thus, the problems of controller parameter adjustment being time-consuming and labor-intensive in the related art, requiring a large amount of static simulation to finally achieve the optimization goal and having low flexibility, the pitch angle scheduling table being difficult to modify according to the real-time operating conditions, and the limitation of the sensor that it can only detect the blade root bending moment but cannot measure the rotor thrust, so it is impossible to form a closed loop of the rotor thrust to formulate a closed-loop control strategy, and the difficulty in achieving dynamic thrust reduction are solved.

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

[0041] in, is the aerodynamic thrust reference value, is the estimated aerodynamic thrust, is the proportional control coefficient, is the proportional control coefficient, is the pitch angle command value output by the PI controller, β DPS is the pitch angle command value finally output by the anti-saturation PI controller, β GSPI is the unified pitch controller command value.

[0042] Specifically, Figure 2 A flow chart of a dynamic thrust reduction method for wind turbine load suppression provided in an embodiment of the present application.

[0043] like Figure 2 As shown, the dynamic thrust reduction method for load suppression of a wind turbine generator set comprises the following steps:

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

[0045]

[0046] Among them, F a,j is the aerodynamic thrust of the entire blade, N nodes is the number of nodes that the leaf is divided into, r i is the distance between the ith leaf node and the leaf root, v ∞ is the inflow velocity, a i is the local axial induction factor, Ω r is the wind wheel speed, is the local tangential induction factor, C n,i is the normal force coefficient, c i is the local chord length, ρ is the air density, dr i is the unit chord length.

[0047] It is understandable to those skilled in the art that measuring the rotor thrust of a wind turbine plays a great role in achieving dynamic thrust reduction of the wind turbine. If the rotor thrust of a wind turbine can be measured, thrust reduction can be achieved more directly. Dynamic thrust reduction of wind turbine load suppression can be understood here as reducing the dynamic load borne by the wind turbine during operation, thereby improving the reliability and service life of the unit. Among them, dynamic thrust reduction refers to reducing the front and rear thrust changes of the impeller caused by factors such as wind speed changes by adjusting the control strategy of the unit during the operation of the wind turbine, thereby reducing the dynamic load borne by the unit, thereby extending the service life of the unit and reducing failures and maintenance costs caused by excessive loads.

[0048] However, due to sensor limitations, wind turbine measurement equipment can only detect the flapping moment in the out-of-plane direction and the shimmy bending moment in the in-plane direction of the blade root. The rotor thrust cannot be measured, so it is impossible to directly formulate a closed-loop control strategy based on the rotor thrust.

[0049] Based on this, when implementing dynamic thrust reduction of wind turbine load suppression, the embodiment of the present application can first estimate the rotor thrust of the target wind turbine based on the out-of-plane bending moment of the blade root of the target wind turbine to achieve dynamic thrust reduction of the target wind turbine. The target wind turbine here can be understood as the wind turbine for which dynamic thrust reduction is desired.

[0050] The estimated expression of the rotor thrust can be, but is not limited to, expressed as:

[0051]

[0052] Among them, F a,j is the aerodynamic thrust of the entire blade, N nodes is the number of nodes that the leaf is divided into, r i is the distance between the ith leaf node and the leaf root, v ∞ is the inflow velocity, a i is the local axial induction factor, Ω r is the wind wheel speed, is the local tangential induction factor, C n,i is the normal force coefficient, c i is the local chord length, ρ is the air density, dr i is the unit chord length.

[0053] The out-of-plane bending moment of the blade root in the embodiment of the present application is also called the blade root flapping moment, which refers to an important type of bending moment to which the root of the wind turbine blade is subjected. Under the action of wind force, the blade of the wind turbine will generate a bending moment around its axis, which mainly acts in the flapping direction of the blade. The flapping moment is mainly generated by aerodynamic thrust and is the result of the action of aerodynamic load on the blade. When the wind acts on the blade, a force perpendicular to the plane of the blade is generated, which causes the blade to bend and deform in the flapping direction, thereby forming a flapping moment.

[0054] Next, a further explanation is given of the process of estimating the rotor thrust of the target wind turbine generator set by the out-of-plane bending moment of the blade root of the target wind turbine generator set in the embodiment of the present application.

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

[0056] In the actual implementation process, when the present application estimates the rotor thrust of the target wind turbine set through the out-of-plane bending moment of the blade root of the target wind turbine set, it can be implemented based on the blade element momentum theory. Among them, the blade element momentum theory is one of the main methods for wind turbine blade design and aerodynamic performance calculation, and is a combination of blade element theory and momentum theory. Simply put, the blade element momentum theory can be understood as dividing the blade along the radial direction into a number of infinitely thin blade units, which are called "blade elements". When air flows through the blade element, a pressure difference is formed on the surface of the blade element. This pressure difference will produce a momentum change in the air flow in and out of the blade element, thereby driving the wind wheel to rotate and do work. The specific process can be expressed as follows:

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

[0058]

[0059] Among them, C p and C t are the power coefficient and thrust coefficient, and a is the axial induction factor.

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

[0061]

[0062] Among them, β twist,i is the local twist angle and β is the pitch angle.

[0063] According to the geometric relationship, the following expression can be obtained:

[0064]

[0065] Among them, v ∞ is the inflow velocity, r iis the distance between the ith leaf node and the leaf root, is the local tangential induction factor, a i is the local axial induction factor, Ω r is the wind wheel speed.

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

[0067]

[0068] in,

[0069]

[0070] Eliminate φ i , we can get the following expression:

[0071]

[0072] Solving the above equation and selecting the positive solution, we can get the following expression:

[0073]

[0074] Taking the annular flow tube microelement with radial height dr on the blade as an example, according to the axial and tangential moment theorem, the thrust F acting on the blade microelement is a,i , torque T a,i and power P a,i They can be expressed as:

[0075]

[0076] also,

[0077]

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

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

[0080]

[0081] Among them, n b is the number of leaves, c i is the local chord length, Wi is the combined inflow velocity, which can be expressed as follows:

[0082]

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

[0084]

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

[0086]

[0087] Solving the above two equations together, we can get the following expression:

[0088]

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

[0090]

[0091] For the sake of brevity, the embodiments of the present application may be described as follows:

[0092]

[0093] After finishing, we can get:

[0094]

[0095] It should be noted that this is a quartic equation. Since quartic equations have analytical solutions, we can solve a analytically. i .

[0096] Therefore, the aerodynamic thrust of the entire blade can be calculated based on the local aerodynamic thrust. The formula can be expressed as follows:

[0097]

[0098] Among them, N nodes is the number of nodes that the leaf is divided into.

[0099] Step S202: estimating the equivalent force arm of the rotor of the target wind turbine generator system based on the out-of-plane bending moment at the blade root and the rotor thrust.

[0100] Among them, the estimation expression of the equivalent force arm can be:

[0101]

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

[0103] It is understandable that during the rotation of the wind turbine rotor, the wind force on the blades will generate a rotational torque, which can be regarded as an equivalent force acting on an equivalent force arm. The "equivalent force arm" in the embodiment of the present application can be understood as a virtual parameter used to describe the effect of rotor rotation.

[0104] As a possible implementation method, the embodiment of the present application can construct the relationship between the unmeasurable rotor thrust and the measurable out-of-plane torque of the blade root through an equivalent force arm. Following the calculation process of the target wind turbine in the previous embodiment, the calculation process of the equivalent force arm can be expressed as follows:

[0105] Expanding (18) yields:

[0106]

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

[0108]

[0109] In the embodiment of the present application, the lift and drag acting on each blade node on the blade can be equivalent to a composite force and moment with an equivalent force arm L, but is not limited to: eq , which can be expressed as follows:

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

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

[0112]

[0113] The embodiment of the present application can be based on a rotor thrust estimation method of a simplified blade element momentum theory, and the rotor thrust and torque are solved by analytical solutions, and the equivalent force arm is estimated accordingly, so that dynamic thrust reduction of the wind turbine load can be achieved according to the equivalent force arm and the rotor thrust.

[0114] Step S203 , generating a rotor thrust instruction for reducing the actual rotor thrust to the target rotor thrust according to the equivalent force arm and the actual rotor thrust of the target wind turbine generator set, so as to reduce the load of the target wind turbine generator set to the target load corresponding to the target rotor thrust.

[0115] As a possible implementation method, after calculating the equivalent force arm of the rotor of the wind turbine, in actual application, the embodiment of the present application can generate a rotor thrust instruction for reducing the actual rotor thrust to the target rotor thrust based on the combination of the equivalent force arm and the actual rotor thrust of the target wind turbine, and use a controller such as an anti-saturation PI controller to reduce the load of the target wind turbine to a target load.

[0116] The target rotor thrust here can be understood as the rotor thrust value or rotor thrust range that the target wind turbine group hopes to achieve. The target load can be understood as the load of the target wind turbine group corresponding to the reduction of the rotor thrust near a certain wind speed. The anti-saturation proportional-integral controller can be expressed as follows:

[0117]

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

[0119] The embodiment of the present application can calculate and combine the equivalent force arm and the actual rotor thrust to achieve dynamic thrust reduction for target wind turbine load suppression, which can effectively improve the efficiency of dynamic thrust reduction while simplifying the operation.

[0120] Optionally, in one embodiment of the present application, a rotor thrust instruction for reducing the actual rotor thrust to a target rotor thrust is generated according to the equivalent force arm and the actual rotor thrust of the target wind turbine generator set, including: determining a target blade pitch angle of the target wind turbine generator set; and determining the rotor thrust instruction based on the target blade pitch angle.

[0121] It is understandable that the anti-saturation PI controller is a control algorithm that can accurately track the target value while ensuring the stability of the target wind turbine system. In the embodiment of the present application, 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 rotor thrust command value to be specified. Among them, the target blade pitch angle can be understood as the blade pitch angle corresponding to the target wind turbine when the dynamic thrust is reduced to a certain target rotor thrust.

[0122] In other embodiments, the present application may use an anti-saturation proportional integral (PI) controller to determine the target blade pitch angle, so as to determine the rotor thrust command during dynamic thrust reduction according to the target blade pitch angle. That is, by adjusting the blade pitch angle, the aerodynamic force and aerodynamic bending moment on the blade can be changed, thereby achieving dynamic reduction of rotor thrust.

[0123] Optionally, in one embodiment of the present application, before generating a rotor thrust instruction based on the equivalent force arm and in combination with the actual rotor thrust of the target wind turbine generator set, it also includes: calculating the actual blade root out-of-plane bending moment of the target wind turbine generator set; and obtaining the actual rotor thrust using the actual blade root out-of-plane bending moment.

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

[0125] In practical applications, the embodiments of the present application can estimate the actual rotor thrust of a target wind turbine group based on the actual out-of-plane bending moment of the blade root of the wind turbine group, because the flapping bending moment in the out-of-plane direction of the blade root can be detected by measuring equipment such as a wind turbine, thereby measuring the actual rotor thrust of the target wind turbine group, and further directly realizing the dynamic thrust reduction of the target wind turbine group, and flexibly adjusting the rotor thrust command value to achieve optimized operation of the wind turbine group.

[0126] According to the dynamic thrust reduction method for load suppression of wind turbines proposed in the embodiment of the present application, the rotor thrust and torque can be solved by analytical solution based on the simplified blade element momentum theory, and the equivalent force arm can be estimated accordingly, and then the blade pitch angle can be determined by using an anti-saturation proportional integral (PI) controller to achieve dynamic thrust reduction for load suppression of wind turbines. In this way, the actual rotor thrust of the wind turbine can be estimated based on the out-of-plane bending moment of the blade root when only three set control parameters are required, and then the relationship between the unmeasurable rotor thrust and the measurable out-of-plane moment of the blade root is constructed through the equivalent force arm, so that thrust reduction can be achieved more directly, the wide range of available parameters can also ensure the control effect in a large range, and the rotor thrust command value can be specified according to actual needs, which greatly improves the flexibility of use of the present application and reduces 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 ultimately achieve the optimization goal and low flexibility, the difficulty in modifying the pitch angle scheduling table according to real-time operating conditions, and the limitation of the sensor that it can only detect the blade root bending moment and cannot measure the rotor thrust. Therefore, it is impossible to form a closed loop of the rotor thrust to formulate a closed-loop control strategy, and dynamic thrust reduction is difficult to achieve.

[0127] Next, a dynamic thrust reduction device for load suppression of a wind turbine set proposed in accordance with an embodiment of the present application will be described with reference to the accompanying drawings.

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

[0129] like Figure 3 As shown, the dynamic thrust reduction device 10 for load suppression of a wind turbine generator set 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 generator set by the out-of-plane bending moment of the blade root of the target wind turbine generator set;

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

[0132] The reduction module 300 is used to generate a rotor thrust instruction for reducing the actual rotor thrust to the target rotor thrust according to the equivalent force arm and the actual rotor thrust of the target wind turbine group, so as to reduce the load of the target wind turbine group to the target load corresponding to the target rotor thrust.

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

[0134] Wherein, the calculation unit is used to calculate the aerodynamic thrust and torque of the blade micro-element of the target wind turbine generator set 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 generator set through the aerodynamic thrust and torque of the blade micro-element, so as to estimate the rotor thrust according to the aerodynamic thrust of the entire blade.

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

[0137] Wherein, the first determination unit is used to determine a target blade pitch angle of a target wind turbine;

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

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

[0140] The first calculation module is used to calculate the actual blade root out-of-plane bending moment of the target wind turbine generator set before generating the rotor thrust instruction according to the equivalent force arm and the actual rotor thrust of the target wind turbine generator set;

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

[0142] Optionally, in one embodiment of the present application, the estimated expression of the rotor thrust may be:

[0143]

[0144] Among them, F a,j is the aerodynamic thrust of the entire blade, N nodes is the number of nodes that the leaf is divided into, r i is the distance between the ith leaf node and the leaf root, v ∞ is the inflow velocity, a i is the local axial induction factor, Ω r is the wind wheel speed, is the local tangential induction factor, C n,i is the normal force coefficient, c i is the local chord length, ρ is the air density, dr i is the unit chord length.

[0145] Optionally, in one embodiment of the present application, the estimation expression of the equivalent force arm may be:

[0146]

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

[0148] It should be noted that the above explanation of the embodiment of the dynamic thrust reduction method for load suppression of a wind turbine generator set is also applicable to the dynamic thrust reduction device for load suppression of a wind turbine generator set of this embodiment, and will not be repeated here.

[0149] According to the dynamic thrust reduction device for load suppression of wind turbines proposed in the embodiment of the present application, the rotor thrust and torque can be solved by analytical solution based on the simplified blade element momentum theory, and the equivalent force arm can be estimated accordingly, and then the blade pitch angle can be determined by using an anti-saturation proportional integral (PI) controller to achieve dynamic thrust reduction for load suppression of wind turbines. In this way, the actual rotor thrust of the wind turbine can be estimated based on the out-of-plane bending moment of the blade root when only three set control parameters are required, and then the relationship between the unmeasurable rotor thrust and the measurable out-of-plane moment of the blade root is constructed through the equivalent force arm, so that thrust reduction can be achieved more directly, the wide range of available parameters can also ensure the control effect in a large range, and the rotor thrust command value can be specified according to actual needs, which greatly improves the flexibility of use of the present application and reduces 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 ultimately achieve the optimization goal and low flexibility, the difficulty in modifying the pitch angle scheduling table according to real-time operating conditions, and the limitation of the sensor that it can only detect the blade root bending moment and cannot measure the rotor thrust. Therefore, it is impossible to form a closed loop of the rotor thrust to formulate a closed-loop control strategy, and dynamic thrust reduction is difficult to achieve.

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

[0151] Memory 401 , processor 402 , and a computer program stored in the memory 401 and executable on the processor 402 .

[0152] When the processor 402 executes the program, the dynamic thrust reduction method for wind turbine load suppression provided in the above embodiment is implemented.

[0153] Furthermore, the electronic device further comprises:

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

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

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

[0157] If the memory 401, the processor 402 and the communication interface 403 are implemented independently, the communication interface 403, the memory 401 and the processor 402 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, 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 only one type of bus.

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

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

[0160] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned dynamic thrust reduction method for load suppression of a wind turbine set.

[0161] The embodiment of the present application also provides a computer program product, including a computer program, which can run computer instructions. When the computer instructions are executed by a processor, the dynamic thrust reduction method for wind turbine load suppression provided in the embodiment of the present application is implemented.

[0162] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0163] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and 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 the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0165] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0166] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0167] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0168] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0169] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A dynamic thrust reduction method for wind turbine load suppression, characterized in that: The following steps are involved: estimating the rotor thrust of the target wind turbine generator set by using the out-of-plane bending moment of the blade root of the target wind turbine generator set; estimating an equivalent force arm of a rotor of the target wind turbine generator system based on the blade root out-of-plane bending moment and the rotor thrust; A rotor thrust instruction for reducing the actual rotor thrust to a target rotor thrust is generated according to the equivalent force arm and the actual rotor thrust of the target wind turbine generator set, so as to reduce the load of the target wind turbine generator set to a target load corresponding to the target rotor thrust.

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

3. The method according to claim 1, characterized in that The generating, according to the equivalent force arm and the actual rotor thrust of the target wind turbine group, a rotor thrust instruction for reducing the actual rotor thrust to a target rotor thrust comprises: Determining a target blade pitch angle of the target wind turbine; The rotor thrust command is determined based on the target blade pitch angle.

4. The method according to claim 1, characterized in that: Before generating a rotor thrust instruction for reducing the actual rotor thrust to a target rotor thrust according to the equivalent force arm and the actual rotor thrust of the target wind turbine generator set, the method further includes: Calculating the actual out-of-plane bending moment of the blade root of the target wind turbine; The actual rotor thrust is obtained by using the actual blade root out-of-plane bending moment.

5. The method according to claim 2, characterized in that: The estimated expression of the rotor thrust is: Among them, F a,j is the aerodynamic thrust of the entire blade, N nodes is the number of nodes that the leaf is divided into, r i is the distance between the ith leaf node and the leaf root, v ∞ is the inflow velocity, a i is the local axial induction factor, Ω r is the wind wheel speed, is the local tangential induction factor, C n,i is the normal force coefficient, c i is the local chord length, ρ is the air density, dr i is the unit chord length.

6. The method according to claim 1, characterized in that The estimated expression of the equivalent force arm is: Among them, L eq is the equivalent force arm, N nodes is the number of nodes that the leaf is divided into, v ∞ is the inflow velocity, a i is the local axial induction factor, Ω r is the wind wheel speed, is the local tangential induction factor, C n,i is the normal force coefficient, c i is the local chord length, r i is the distance between the i-th leaf node and the leaf root.

7. A dynamic thrust reduction device for load suppression of a wind turbine, characterized in that: include: A first estimation module, configured to estimate the rotor thrust of the target wind turbine generator set by using the out-of-plane bending moment of the blade root of the target wind turbine generator set; A second estimation module, configured to estimate an equivalent force arm of a rotor of the target wind turbine generator set based on the blade root out-of-plane bending moment and the rotor thrust; The reduction module is used to generate a rotor thrust instruction for reducing the actual rotor thrust to a target rotor thrust according to the equivalent force arm and the actual rotor thrust of the target wind turbine group, so as to reduce the load of the target wind turbine group to a target load corresponding to the target rotor thrust.

8. An electronic device, characterized in that: include: 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 load suppression of a wind turbine set as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the dynamic thrust reduction method for load suppression of a wind turbine set as described in any one of claims 1 to 6.

10. 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 1-6.

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