Control method, equipment and program product of wind generating set

Abstract

The invention discloses a control method and device of a wind generating set and a program product. In the method, operation parameters of the wind generating set are obtained; under the condition that the operation parameters meet the control conditions, it is determined that the wind generating set is in the grid-connected rotating speed control stage, the control parameters are obtained, and the first corresponding relation between the control parameters and the pitch angle is obtained; determining target pitch angle data corresponding to the control parameters according to the control parameters and the first corresponding relation between the control parameters and the pitch angles. The determined target pitch angle data is the pitch angle data when the wind generating set achieves the better output power in the current operation state. And controlling the wind generating set according to the target pitch angle data. Therefore, in the grid-connected rotating speed control stage, the pitch angle of the wind generating set is optimized according to the control parameters, so that the output power of the wind generating set is improved, and the generating capacity of the wind generating set is improved at a low wind speed.

Description

Technical Field

[0001] The present application relates to the field of wind power technology, and in particular to a control method, device and program product for a wind turbine generator set. Background Art

[0002] During the operation of a wind turbine generator set, when the output power of the generator is less than the rated power, the pitch angle remains unchanged at zero degrees; when the output power of the generator is equal to or greater than the rated power, the pitch angle is adjusted according to the change in output power to keep the output power of the generator at the rated power. By adjusting the pitch angle, wind energy can be fully utilized and the wind turbine generator set can be protected from damage caused by excessive wind speed.

[0003] However, under certain operating conditions, the output power of wind turbines is low and wind energy cannot be fully utilized. Summary of the invention

[0004] In view of this, the present application provides a control method, device and program product for a wind turbine generator set, which can improve the output power of the wind turbine generator set during the grid-connected speed control stage.

[0005] The technical solutions provided by this application are as follows:

[0006] In a first aspect, the present application provides a control method for a wind turbine generator set, the method comprising:

[0007] Acquire operating parameters of the wind turbine generator set, wherein the operating parameters include impeller speed and motor torque;

[0008] When it is determined that the operating parameter satisfies the control condition, obtaining the control parameter, wherein the control condition is used to determine that the wind turbine generator set is in the grid-connected speed control stage;

[0009] Acquire a first corresponding relationship between a control parameter and a pitch angle;

[0010] Determining target pitch angle data corresponding to the control parameter according to the control parameter and a first corresponding relationship between the control parameter and the pitch angle;

[0011] The wind turbine generator set is controlled according to the target pitch angle data.

[0012] Optionally, acquiring a first corresponding relationship between a control parameter and a pitch angle includes:

[0013] obtaining a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle;

[0014] Get the value of the tip speed ratio;

[0015] According to the second corresponding relationship and the value of the tip speed ratio, a first corresponding relationship between the control parameter and the pitch angle is determined.

[0016] Optionally, acquiring a second corresponding relationship among the tip speed ratio, the control parameter, and the pitch angle includes:

[0017] determining a third correspondence between the tip speed ratio, the power coefficient of the wind turbine generator set and the pitch angle;

[0018] Determining a fourth corresponding relationship between the power coefficient of the wind turbine generator set and the control parameter;

[0019] According to the third corresponding relationship and the fourth corresponding relationship, a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle is determined.

[0020] Optionally, determining a second corresponding relationship among the tip speed ratio, the control parameter, and the pitch angle according to the third corresponding relationship and the fourth corresponding relationship includes:

[0021] When the power coefficient of the wind turbine generator set meets a predetermined condition, a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle is determined according to the third corresponding relationship and the fourth corresponding relationship.

[0022] Optionally, the predetermined condition is that the power coefficient of the wind turbine generator set is greater than or equal to a power coefficient threshold.

[0023] Optionally, obtaining the value of the tip speed ratio includes:

[0024] Obtaining wind speed, impeller speed of the wind turbine generator set, and impeller radius of the wind turbine generator set;

[0025] The value of the tip speed ratio is determined according to the impeller rotation speed, the wind speed and the impeller radius.

[0026] Optionally, the first correspondence between the control parameter and the pitch angle includes a plurality of sub-correspondences, and the sub-correspondences include correspondences between control parameters belonging to a sub-value range and a numerical value of a pitch angle.

[0027] Optionally, the control condition is that the difference between the impeller speed and the minimum impeller speed threshold is less than or equal to the difference threshold, and the motor torque is less than the grid-connected control torque threshold.

[0028] Optionally, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between shaft power and the pitch angle;

[0029] Alternatively, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between the motor torque and the pitch angle;

[0030] Alternatively, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between wind speed and the pitch angle.

[0031] In a second aspect, the present application provides a control device for a wind turbine generator set, the device comprising:

[0032] A first acquisition module is used to acquire operating parameters of the wind turbine generator set, wherein the operating parameters include impeller speed and motor torque;

[0033] A second acquisition module is used to acquire a control parameter when it is determined that the operating parameter meets a control condition, wherein the control condition is used to determine that the wind turbine generator set is in a grid-connected speed control stage;

[0034] A third acquisition module is used to acquire a first corresponding relationship between the control parameter and the pitch angle;

[0035] A determination module, configured to determine target pitch angle data corresponding to the control parameter according to the control parameter and a first corresponding relationship between the control parameter and the pitch angle;

[0036] A control module is used to control the wind turbine generator set according to the target pitch angle data.

[0037] Optionally, acquiring a first corresponding relationship between a control parameter and a pitch angle includes:

[0038] obtaining a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle;

[0039] Get the value of the tip speed ratio;

[0040] A first corresponding relationship between a control parameter and a pitch angle is determined according to the second corresponding relationship and the value of the tip speed ratio.

[0041] Optionally, acquiring a second corresponding relationship among the tip speed ratio, the control parameter, and the pitch angle includes:

[0042] determining a third correspondence between the tip speed ratio, the power coefficient of the wind turbine generator set and the pitch angle;

[0043] Determining a fourth corresponding relationship between the power coefficient of the wind turbine generator set and the control parameter;

[0044] According to the third corresponding relationship and the fourth corresponding relationship, a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle is determined.

[0045] Optionally, determining a second corresponding relationship among the tip speed ratio, the control parameter, and the pitch angle according to the third corresponding relationship and the fourth corresponding relationship includes:

[0046] When the power coefficient of the wind turbine generator set meets a predetermined condition, a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle is determined according to the third corresponding relationship and the fourth corresponding relationship.

[0047] Optionally, the predetermined condition is that the power coefficient of the wind turbine generator set is greater than or equal to a power coefficient threshold.

[0048] Optionally, obtaining the value of the tip speed ratio includes:

[0049] Obtaining wind speed, impeller speed of the wind turbine generator set, and impeller radius of the wind turbine generator set;

[0050] The value of the tip speed ratio is determined according to the impeller rotation speed, the wind speed and the impeller radius.

[0051] Optionally, the first correspondence between the control parameter and the pitch angle includes a plurality of sub-correspondences, and the sub-correspondences include correspondences between control parameters belonging to a sub-value range and a numerical value of a pitch angle.

[0052] Optionally, the control condition is that the difference between the impeller speed and the minimum impeller speed threshold is less than or equal to the difference threshold, and the motor torque is less than the grid-connected control torque threshold.

[0053] Optionally, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between shaft power and the pitch angle;

[0054] Alternatively, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between the motor torque and the pitch angle;

[0055] Alternatively, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between wind speed and the pitch angle.

[0056] In a third aspect, the present application provides an electronic device, including:

[0057] one or more processors;

[0058] a storage device having one or more programs stored thereon,

[0059] When the one or more programs are executed by the one or more processors, the one or more processors implement any method described in the first aspect.

[0060] In a fourth aspect, the present application provides a computer program product, which, when executed on a device, enables the device to execute the method according to the first aspect.

[0061] It can be seen that this application has the following beneficial effects:

[0062] The present application provides a control method, device and program product of a wind turbine generator set, in which the operating parameters of the wind turbine generator set are obtained. The operating parameters include the impeller speed and the motor control torque. The operating stage of the wind turbine generator set can be determined according to the operating parameters. It is judged whether the operating parameters meet the control conditions. The control conditions are used to determine that the wind turbine generator set is in the grid-connected speed control stage. When it is determined that the operating parameters meet the control conditions, the control parameters are obtained. The first corresponding relationship between the control parameters and the pitch angle is obtained. The first corresponding relationship between the control parameters and the pitch angle is used to guide the adjustment of the pitch angle of the wind turbine generator set. According to the control parameters and the first corresponding relationship between the control parameters and the pitch angle, the target pitch angle data corresponding to the control parameters is determined. The determined target pitch angle data is the pitch angle data that achieves a better output power of the wind turbine generator set under the current operating state. According to the target pitch angle data, the wind turbine generator set is controlled. In this way, in the grid-connected speed control stage, the pitch angle of the wind turbine generator set is optimized based on the control parameters of the wind turbine generator set, thereby increasing the output power of the wind turbine generator set and achieving the increase in the power generation of the wind turbine generator set at low wind speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0064] Figure 1 A schematic diagram of the operation phase of a wind turbine generator set provided in an embodiment of the present application;

[0065] Figure 2 A schematic diagram of a blade provided in an embodiment of the present application;

[0066] Figure 3 A schematic diagram of a performance curve of a wind turbine generator set provided in an embodiment of the present application;

[0067] Figure 4 A schematic diagram of another blade provided in an embodiment of the present application;

[0068] Figure 5 A schematic diagram of a performance curve of another wind turbine generator set provided in an embodiment of the present application;

[0069] Figure 6 A schematic diagram of another blade provided in an embodiment of the present application;

[0070] Figure 7A schematic diagram of a scenario provided for an embodiment of the present application;

[0071] Figure 8 A schematic diagram of a flow chart of a control method for a wind turbine generator set provided in an embodiment of the present application;

[0072] Fig. 9 A schematic diagram of a performance curve of a wind turbine generator set provided in an embodiment of the present application;

[0073] Fig.10 A schematic diagram of a wind speed probability distribution curve provided in an embodiment of the present application;

[0074] Fig.11 A schematic diagram of a third corresponding relationship provided in an embodiment of the present application;

[0075] Fig.12 A schematic diagram of a first corresponding relationship provided in an embodiment of the present application;

[0076] Fig.13 A schematic diagram of a corresponding relationship between a pitch angle and a wind speed provided in an embodiment of the present application;

[0077] Fig.14 A schematic diagram of a power change situation provided in an embodiment of the present application;

[0078] Fig.15 A schematic diagram of another correspondence between pitch angle and wind speed provided in an embodiment of the present application;

[0079] Fig.16 A schematic structural diagram of a control device for a wind turbine generator set provided in an embodiment of the present application. DETAILED DESCRIPTION

[0080] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0081] In order to facilitate the understanding and explanation of the technical solutions provided by the embodiments of the present application, the background technology involved in the embodiments of the present application is first introduced.

[0082] At present, wind turbines are basically pitch regulated wind turbines, and the blade angle can be adjusted according to the change of wind speed. The operation process of wind turbines is divided into four stages based on wind speed. Figure 1As shown, this figure is a schematic diagram of the operation stage of a wind turbine generator set provided by an embodiment of the present application. Among them, the horizontal axis is the wind speed, and the vertical axis represents the value. Line A represents the rotation speed of the wind turbine generator set. Line B represents the power of the wind turbine generator set. Line C represents the pitch angle of the wind turbine generator set. Figure 1 In the control process, the first stage is the grid-connected speed control stage. The second stage is the optimal gain control stage, also known as the optimal tip speed ratio control stage. The third stage is the torque closed-loop control stage. The fourth stage is the pitch angle closed-loop control stage. Closed-loop control is a control method in which the controlled output returns to the input end of the control and exerts a control influence on the input end.

[0083] The grid-connected speed control stage refers to the control stage in which the speed of the wind turbine is maintained at the minimum speed through the motor torque. In the grid-connected speed control stage, that is, in the first stage, as the wind speed gradually increases, the power of the wind turbine gradually increases. When the grid-connected torque is reached, the control state of the wind turbine is switched to the optimal gain control stage, that is, the second stage. Optimal gain control (Optimal gain control strategy) refers to the use of the optimal gain control method when the speed of the wind turbine is below the rated speed, so that the wind turbine operates in the optimal power coefficient state. In the second stage, the wind turbine is in the open-paddle state. The pitch angle of the blade is a fixed value, which is the minimum pitch angle. The pitch angle of the blade is usually around 0°. After the speed of the wind turbine reaches the rated speed, it enters the third stage. In the third stage, the speed of the wind turbine reaches the rated speed, but the output power of the wind turbine does not reach the rated power. The pitch angle still remains in the open-paddle state. After the output power of the wind turbine reaches the rated power, it enters the fourth stage. In the fourth stage, the output power of the wind turbine reaches the rated power, and the speed of the wind turbine is controlled by the pitch angle.

[0084] Blade element momentum theory is a method for calculating the aerodynamic loads on wind turbine blades. Blades are the many micro-segments that wind turbine blades are divided into along the span direction. Blade element momentum theory combines momentum theory with the principle of force balance of two-dimensional airfoils, and obtains a closed-form solution by iteratively solving the momentum equation. Based on blade element momentum theory, the aerodynamic characteristics of two-dimensional airfoils are analyzed, see Figure 2 As shown in the figure, this figure is a schematic diagram of a blade provided in an embodiment of the present application. Wherein, α represents the angle of attack. The angle of attack is the angle between the airflow velocity vector and the airfoil chord line. γ represents the inflow angle. The inflow angle is the angle formed by the blade element linear velocity and the incoming flow velocity. θ p represents the pitch angle. arepresents the aerodynamic twist angle corresponding to the blade element. β represents the torsional deformation corresponding to a blade element. When the torsional deformation of the blade is small, β≈0°. W is the flow velocity. L represents the lift and D represents the drag. V X is the axial induced wind speed, V Y is the circumferential induced velocity.

[0085] In the first stage, that is, the grid-connected speed control stage, as the wind speed increases, the inflow angle of the wind turbine blades continues to increase, and the blades deviate from the optimal angle of attack, resulting in a decrease in the power coefficient, which in turn causes the wind turbine to be unable to achieve the optimal output power.

[0086] For example, see Figure 3 As shown, this figure is a schematic diagram of a performance curve of a pitch angle adjustable wind turbine provided in an embodiment of the present application, wherein the horizontal axis is the rotation speed and the vertical axis is the shaft power. Figure 3 The mark in indicates that the wind turbine is in the startup state. When the wind speed is U, the pitch angle is maintained near 0°. Figure 4 As shown, for a blade element of a certain blade, the corresponding angle of attack is α, and the angle of attack for the optimal lift-to-drag ratio is α * The blade does not operate at the angle of attack corresponding to its optimal lift-to-drag ratio, resulting in the power coefficient of the entire blade not being the optimal power coefficient.

[0087] Furthermore, in the case of increasing wind speed, see Figure 5 As shown in the figure, under the working condition corresponding to the marked point, the wind speed increases by ΔU, and the angle of attack of the wind turbine gradually increases. Figure 6 As shown, under this working condition, the pitch angle corresponding to the optimal power coefficient changes again.

[0088] At present, in the grid-connected speed control stage, there is a lack of adjustment of the pitch angle of the wind turbine generator set, resulting in a power coefficient that is not optimal. The output power of the wind turbine generator set cannot reach a better output power, and the wind energy cannot be fully utilized.

[0089] It is understandable that the defects in the above solutions are the results obtained by the applicant after practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in the embodiments of the present application for the above problems below should be the contributions made by the applicant to the embodiments of the present application during the application process.

[0090] Based on this, the embodiment of the present application provides a control method, device and program product of a wind turbine generator set, in which the operating parameters of the wind turbine generator set are obtained. The operating parameters include the impeller speed and the motor control torque. According to the operating parameters, the operating stage of the wind turbine generator set can be determined. It is judged whether the operating parameters meet the control conditions. The control conditions are used to determine that the wind turbine generator set is in the grid-connected speed control stage. When it is determined that the operating parameters meet the control conditions, the control parameters are obtained. The first corresponding relationship between the control parameters and the pitch angle is obtained. The first corresponding relationship between the control parameters and the pitch angle is used to guide the adjustment of the pitch angle of the wind turbine generator set. According to the control parameters and the first corresponding relationship between the control parameters and the pitch angle, the target pitch angle data corresponding to the control parameters is determined. The determined target pitch angle data is the pitch angle data that achieves a better output power of the wind turbine generator set under the current operating state. According to the target pitch angle data, the wind turbine generator set is controlled. In this way, in the grid-connected speed control stage, the pitch angle of the wind turbine generator set is optimized based on the control parameters of the wind turbine generator set, thereby increasing the output power of the wind turbine generator set and achieving the increase in the power generation of the wind turbine generator set at low wind speeds.

[0091] In order to facilitate the understanding of the technical solution provided by the embodiment of the present application, the following is a Figure 7 A control method for a wind turbine generator set provided in an embodiment of the present application is described.

[0092] The control method of the wind turbine generator set provided in the embodiment of the present application can be applied to the control system of the wind turbine generator set. Figure 7 As shown, the control system includes three modules, namely, an analysis module, a detection module and a control module. The analysis module is used to analyze the performance of the wind turbine generator set, and obtain the first correspondence between the shaft power and the pitch angle based on the tip speed ratio and the blade element momentum theory. The first correspondence between the shaft power and the pitch angle is embodied in a table of shaft power-pitch angle. The detection module is used to obtain operating parameters, and when it is determined according to the operating parameters that the wind turbine generator set is in the grid-connected speed control stage, the shaft power is obtained. The operating parameter is, for example, the impeller speed.

[0093] The control module is used to determine target pitch angle data corresponding to the shaft power according to the shaft power and the first corresponding relationship between the shaft power and the pitch angle, and control the wind turbine generator set according to the target pitch angle data.

[0094] As an example, the analysis module obtains the minimum thresholds of wind speed and impeller speed. The analysis module calculates the first correspondence between the control parameter and the pitch angle based on the minimum thresholds of wind speed and impeller speed. For example, the control parameter is shaft power (ShaftPower). Shaft power is the aerodynamic power of the wind turbine. The aerodynamic power is the power excluding electrical and mechanical losses. The analysis module sends the first correspondence to the control module. The detection module obtains operating parameters, including impeller speed and motor torque. The detection module determines that the wind turbine is in the grid-connected speed control stage based on the operating parameters. The detection module sends a control instruction to the control module. The control module obtains the control parameter and determines the target pitch angle data corresponding to the control parameter according to the first correspondence. The control module controls the wind turbine according to the target pitch angle data.

[0095] Those skilled in the art will understand that Figure 7 The schematic diagram shown is only an example in which the embodiments of the present application can be implemented. The scope of application of the embodiments of the present application is not limited in any aspect by the schematic diagram. Figure 7 The analysis module, detection module and control module shown are, for example, virtual modules based on functional division. Figure 7 The three modules shown can also have other functions. For example, the control module also calls a proportional-integral (PI) controller to calculate the motor torque and control the wind turbine generator set based on the motor torque.

[0096] A control method for a wind turbine generator set provided in an embodiment of the present application is described below.

[0097] See also Figure 8 As shown, the figure is a schematic flow chart of a control method of a wind turbine generator set provided in an embodiment of the present application, including:

[0098] S801: Obtain operating parameters of the wind turbine generator set.

[0099] The operating parameters of a wind turbine generator set can reflect the control stage that the wind turbine generator set is in. The operating parameters include the impeller speed and the motor torque. Based on the impeller speed and the motor torque, the control stage of the wind turbine generator set is determined.

[0100] The embodiment of the present application does not limit the method of obtaining the operating parameters of the wind turbine generator set. In one possible implementation, based on a preset operating parameter acquisition cycle, the operating parameters are acquired in each operating parameter acquisition cycle. In another possible implementation, the operating parameters are acquired in real time.

[0101] S802: When it is determined that the operating parameters meet the control conditions, obtain the control parameters.

[0102] The control condition is used to determine whether the wind turbine generator set is in the grid-connected speed control stage. The control condition is, for example, that the difference between the impeller speed and the minimum impeller speed threshold is less than or equal to the difference threshold, and the motor torque is less than the grid-connected control torque threshold. The impeller speed minimum threshold, the difference threshold, and the grid-connected control torque threshold are all preset values. As an example, the difference threshold is 0. That is, the control condition is that the impeller speed is the impeller speed minimum threshold, and the motor torque is less than the grid-connected control torque threshold.

[0103] When the operating parameters meet the control conditions, it indicates that the wind turbine generator set is in the grid-connected speed control stage. In the grid-connected speed control stage, the pitch angle of the wind turbine generator set needs to be adjusted to achieve the optimal output power. The output power is, for example, shaft power.

[0104] When the wind turbine generator set is in the grid-connected speed control stage, a control parameter is obtained. The control parameter is used to determine the value of the pitch angle. The embodiment of the present application does not limit the specific type of the control parameter. As an example, the control parameter is shaft power. As another example, the control parameter is motor torque. As another example, the control parameter is wind speed.

[0105] S803: Obtain a first corresponding relationship between a control parameter and a pitch angle.

[0106] The first correspondence between the control parameter and the pitch angle may be preset. As an example, the first correspondence between the control parameter and the pitch angle is stored in a data table. The first correspondence between the control parameter and the pitch angle may be calibrated or pre-calculated. In addition, the first correspondence between the control parameter and the pitch angle may also be obtained by real-time calculation.

[0107] As an example, an embodiment of the present application provides a possible implementation method for calculating a first corresponding relationship between a control parameter and a pitch angle, for example, including step A1 and step A2.

[0108] A1: Obtain the second corresponding relationship between the tip speed ratio, the control parameter and the pitch angle.

[0109] As an example, the second corresponding relationship between the tip speed ratio, the control parameter and the pitch angle may be determined by calibration.

[0110] As another example, the second correspondence between the tip speed ratio, the control parameter and the pitch angle is determined based on the third correspondence and the fourth correspondence. The third correspondence is the correspondence between the tip speed ratio, the power coefficient of the wind turbine generator set and the pitch angle. The fourth correspondence is the correspondence between the power coefficient and the control parameter.

[0111] The third corresponding relationship is first introduced below.

[0112] When other conditions remain unchanged, the tip speed ratio of the wind turbine affects the power coefficient of the wind turbine. The higher the tip speed ratio, the higher the output power of the wind turbine. The effect of the tip speed ratio on power can be expressed by the performance curve of the wind turbine (Wind turbine aerodynamic curve). Fig. 9 As shown in FIG. 1 , this figure is a schematic diagram of a performance curve of a wind turbine generator set provided in an embodiment of the present application. The performance curve of a wind turbine generator set is used to describe the power coefficient C of a wind turbine generator. p As the tip speed ratio λ changes, it is also called C p -λ curve. The performance curve of a wind turbine describes the corresponding relationship between the tip speed ratio and the power coefficient. Among them, the power coefficient with the highest value is the optimal power coefficient. The tip speed ratio corresponding to the optimal power coefficient can be expressed as λ opt .

[0113] Furthermore, the pitch angle θ p It also affects the power coefficient C p . Power coefficient C p and pitch angle θ p The third corresponding relationship can be described by the performance surface of the wind turbine generator set (Wind turbine aerodynamic surface). The performance surface of the wind turbine generator set (Wind turbine aerodynamic surface) describes the power coefficient C p With the tip speed ratio λ and pitch angle θ p The surface formed by the law of change of .

[0114] The embodiment of the present application provides a possible implementation method for calculating the third corresponding relationship.

[0115] The expression of the third corresponding relationship is shown in formula (1):

[0116]

[0117] Among them, λ r is the local tip speed ratio of the blade element, λ is the tip speed ratio of the wind turbine generator set, a is the axial induction factor, and b is the circumferential induction factor.

[0118] The expressions of axial induction factor a and circumferential induction factor b are:

[0119]

[0120] Among them, C n is the normal thrust coefficient, C tis the tangential thrust coefficient. F is the Prandtl correction factor, which is used to correct the losses at the root and tip of the blades of the wind turbine. γ is the inflow angle. σ is the solidity.

[0121] Normal thrust coefficient C n and the tangential thrust coefficient C t The lift coefficient C of the blade section can be l and the drag coefficient C d It is represented by formula (4) and (5).

[0122] C n =C l cosγ+C d sinγ (4)

[0123] C t =C l sinγ-C d cosγ (5)

[0124] The expression of F is:

[0125]

[0126] Among them, B is the number of blades, R is the radius of the wind wheel, and r is the radius of the blade.

[0127] The solidity σ is:

[0128]

[0129] Among them, B is the number of blades and c is the chord length.

[0130] The inflow angle γ can be expressed as:

[0131] γ=α+θ p (8)

[0132] Among them, θ p is the pitch angle, and α is the angle of attack. The angle of attack α is related to the lift coefficient C l and the drag coefficient C d There is a corresponding relationship. The angle of attack α and the lift coefficient C l and the drag coefficient C d The corresponding relationship can be calibrated by experimental results.

[0133] In this way, based on the determined angle of attack α, the inflow angle γ and the pitch angle θ can be determined. p The corresponding relationship between and the determination of the lift coefficient C l and the drag coefficient C d According to the value of the inflow angle γ and the pitch angle θ p The corresponding relationship between, as well as formula (4) and formula (5), can obtain the normal thrust coefficient Cn and pitch angle θ p The corresponding relationship between the tangential thrust coefficient C t and pitch angle θ p The corresponding relationship between them.

[0134] According to the inflow angle γ and the pitch angle θ p The corresponding relationship between the normal thrust coefficient C n and pitch angle θ p The corresponding relationship between the tangential thrust coefficient C t and pitch angle θ p The corresponding relationship between and formula (2) and formula (3) gives the axial induction factor a and the pitch angle θ p The corresponding relationship between the circumferential induction factor b and the pitch angle θ p The corresponding relationship between them.

[0135] Finally, according to the axial induction factor a and the pitch angle θ p The corresponding relationship between the circumferential induction factor b and the pitch angle θ p The corresponding relationship between and formula (1) gives the power coefficient C p With tip speed ratio λ and pitch angle θ p The corresponding relationship between them.

[0136] In addition, the power coefficient C p There is also a fourth corresponding relationship between the control parameter. As an example, the control parameter is shaft power. The expression of the fourth corresponding relationship is:

[0137]

[0138] Where P is the shaft power, V ∞ is the wind speed, ρ is the air density, and A is the swept area of ​​the wind turbine.

[0139] In this way, by combining the third corresponding relationship and the fourth corresponding relationship, the second corresponding relationship between the tip speed ratio, the control parameter and the pitch angle can be obtained. The expression of the second corresponding relationship is shown in formula (10):

[0140]

[0141] Among them, the axial induction factor a and the pitch angle θ p There is a corresponding relationship between the circumferential induction factor b and the pitch angle θ p There is a corresponding relationship between them. Air density ρ, wind turbine swept area A, wind speed V ∞ , the local tip speed ratio λ of the blade element r All are known quantities.

[0142] Thus, according to the blade element momentum theory, by integrating the local power coefficients of the blade elements at different positions on the blades of the wind turbine generator set, the overall power coefficient of the wind turbine generator set is determined, and the third corresponding relationship between the power coefficient of the wind turbine generator set and the tip speed ratio and the pitch angle is obtained. In addition, from the perspective of the efficiency of converting the kinetic energy of the wind into mechanical energy, the power coefficient of the wind turbine generator set is determined, and the fourth corresponding relationship between the power coefficient of the wind turbine generator set and the control parameter is obtained. Based on the parameter of the power coefficient of the wind turbine generator set shared by the third and fourth corresponding relationships, the second corresponding relationship between the tip speed ratio, the control parameter and the pitch angle can be determined, and then when the tip speed ratio is determined, the first corresponding relationship between the control parameter and the pitch angle is determined, so as to adjust the pitch angle by using the first corresponding relationship and the obtained value of the control parameter.

[0143] In a possible implementation, when the power coefficient of the wind turbine generator set meets a predetermined condition, a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle is determined according to the third corresponding relationship and the fourth corresponding relationship.

[0144] As an example, the predetermined condition is that the power coefficient is greater than or equal to a power coefficient threshold. The power coefficient threshold is a threshold determined based on the degree of wind energy utilization.

[0145] In this way, after the first corresponding relationship is determined based on the second corresponding relationship, the pitch angle can be adjusted using the first corresponding relationship. The adjusted wind turbine generator set has a higher power coefficient, which can increase the shaft power and power generation of the wind turbine generator set.

[0146] As another example, the predetermined condition is that the power coefficient is an optimal power coefficient. The optimal power coefficient is a power coefficient with the largest value within the value range of the power coefficient. In this way, the optimal pitch angle adjustment effect can be achieved.

[0147] A2: Get the value of the tip speed ratio.

[0148] The value of the tip speed ratio can be determined based on the wind speed and impeller speed, see the following formula:

[0149]

[0150] R is the impeller radius. Ω is the impeller speed. V ∞ is the wind speed.

[0151] In a possible implementation, the value of the tip speed ratio is a preset fixed value. For example, the wind speed is a reference wind speed determined based on the local meteorological data of the wind turbine generator set. The impeller speed is a preset minimum threshold of the impeller speed.

[0152] Based on the local meteorological data of the wind turbine generator set, draw the annual wind speed probability distribution curve. Fig.10 As shown, the wind speed probability distribution curve is a Weibull distribution curve. The Weibull distribution curve is a continuous probability distribution. The probability density is shown in the following formula:

[0153]

[0154] Among them, V ave is the annual average wind speed. k is the shape factor. V is the wind speed variable, which is usually used to describe the probability of wind speed occurrence in a certain area.

[0155] The rated wind speed of the wind turbine generator set is determined based on the wind speed probability distribution curve, and the rated wind speed is used as the reference wind speed.

[0156] In another possible implementation, the impeller radius of the wind turbine is obtained. The wind speed and the impeller speed of the wind turbine are obtained. Based on the wind speed, the impeller speed of the wind turbine and the impeller radius of the wind turbine, the value of the tip speed ratio is determined. The formula for calculating the value of the tip speed ratio is shown in formula (11).

[0157] A3: Determine the first corresponding relationship between the control parameter and the pitch angle according to the second corresponding relationship and the value of the tip speed ratio.

[0158] The second corresponding relationship includes three variables: tip speed ratio, control parameter and pitch angle. According to the acquired value of tip speed ratio and the second corresponding relationship, the first corresponding relationship between the control parameter and the pitch angle is determined.

[0159] For ease of explanation, the principle of determining the first corresponding relationship is explained below in combination with the third corresponding relationship and the fourth corresponding relationship.

[0160] See also Fig.11 As shown, this figure is a schematic diagram of a third corresponding relationship provided in an embodiment of the present application. Fig.11 The horizontal axis of the coordinate system is the pitch angle, and the vertical axis is the power coefficient. The two curves represent the corresponding relationship between the power coefficient and the pitch angle when the tip speed ratio (lambda) is 15 and the tip speed ratio (lambda) is 20.

[0161] After determining the value of the tip speed ratio, the corresponding relationship between the power coefficient and the pitch angle in the third corresponding relationship can be determined, that is, Fig.11 C p -θ p Based on the fourth corresponding relationship between the control parameter and the power coefficient, the first corresponding relationship between the pitch angle and the control parameter can be determined.

[0162] Under the preset condition that the power coefficient is the optimal power coefficient, the corresponding relationship between the power coefficient and the pitch angle is determined according to the value of the tip speed ratio. Based on the corresponding relationship between the power coefficient and the pitch angle, the value of the pitch angle corresponding to the optimal power coefficient is determined. Based on the optimal power coefficient and the fourth corresponding relationship, the value of the control parameter is determined. A first corresponding relationship between the value of the control parameter and the value of the pitch angle is established. In this way, a first corresponding relationship applicable to a variety of situations can be obtained, so that the pitch angle of the wind turbine generator set can be adjusted using the first corresponding relationship.

[0163] As an example, take the control parameter as shaft power, see Fig.12 As shown, this figure is a schematic diagram of a first corresponding relationship provided in an embodiment of the present application.

[0164] In addition, both wind speed and motor torque have a corresponding relationship with shaft power. Wind speed or motor torque can be used as a control parameter.

[0165] In some possible implementations, a first corresponding relationship between wind speed and pitch angle may be determined according to a corresponding relationship between shaft power and pitch angle, and a corresponding relationship between wind speed and shaft power.

[0166] For example, the corresponding relationship between wind speed V and shaft power P can be expressed by formula (14):

[0167] P=0.5πρC ， p R 2 V 3 (14)

[0168] Among them, C ， p It is the power coefficient of the wind turbine during actual operation.

[0169] In some other possible implementations, the first corresponding relationship between the motor torque and the pitch angle may be determined according to the corresponding relationship between the power coefficient and the pitch angle, and the corresponding relationship between the motor torque and the power coefficient.

[0170] For example, the corresponding relationship between shaft power P and motor torque M is shown in formula (15):

[0171] P=ΩM (15)

[0172] Where Ω is the impeller speed.

[0173] In this way, the corresponding pitch angle value can be determined according to the wind speed or the motor torque, thereby adjusting the pitch angle.

[0174] It should be noted that the first correspondence between the control parameter and the pitch angle may include multiple sub-correspondences.

[0175] As an example, the sub-correspondence includes a correspondence between a numerical value of a control parameter and a numerical value of a pitch angle, so that a more accurate adjustment of the pitch angle can be achieved.

[0176] As another example, the sub-correspondence includes a correspondence between a control parameter belonging to a sub-value range and a value of a pitch angle. That is, the control parameters in a sub-value range all correspond to a value of a pitch angle.

[0177] As an example, between the value of the pitch angle at the initial moment of the grid-connected speed control stage and the value of the pitch angle at the end moment of the grid-connected speed control stage, a plurality of pitch angle values ​​are set. The number of pitch angle values ​​is, for example, between 2 and 10. Each pitch angle value corresponds to a value of a control parameter belonging to a sub-value range. In this way, the step-by-step adjustment of the pitch angle can be achieved, the adjustment frequency of the pitch angle can be reduced, and the cost of adjusting the pitch angle can be reduced while increasing the shaft power, thereby avoiding frequent changes in the pitch angle.

[0178] S804: Determine target pitch angle data corresponding to the control parameter according to the control parameter and the first corresponding relationship between the control parameter and the pitch angle.

[0179] The target pitch angle data is used to adjust the pitch angle of the wind turbine generator set.

[0180] S805: Control the wind turbine generator set according to the target pitch angle data.

[0181] Based on the determined target pitch angle data, the pitch angle of the wind turbine generator set is adjusted so that the current pitch angle value of the wind turbine generator set is the target pitch angle data, or the difference with the target pitch angle data is smaller than the adjustment threshold.

[0182] By adopting the control method of the wind turbine generator set provided in the embodiment of the present application, the pitch angle can be adjusted during the grid-connected speed control stage to achieve better power parameters, thereby increasing the output power of the wind turbine generator set and thereby increasing the power generation of the wind turbine generator set.

[0183] See also Fig.13 As shown in FIG. 1 , this figure is a schematic diagram of the corresponding relationship between the pitch angle and the wind speed provided in an embodiment of the present application. Before adopting the control method of the wind turbine generator set provided in the present application, the pitch angle is not adjusted in the grid-connected speed control stage. After adopting the control method of the wind turbine generator set provided in the present application, the pitch angle is flexibly adjusted. For the power change of the wind turbine generator set after adjusting the pitch angle, see Fig.14 As shown in Figure 2, the power of the wind turbine generator set after optimizing the pitch angle is higher than the power of the wind turbine generator set before optimizing the pitch angle.

[0184] See also Fig.15As shown in FIG. 1 , this figure is a schematic diagram of another corresponding relationship between pitch angle and wind speed provided in an embodiment of the present application. The pitch angle at the initial moment of the grid-connected speed control stage Greater than the pitch angle at the end of the grid-connected speed control phase The slope of the pitch angle as the wind speed changes is The value of K is greater than 0.25.

[0185] In this way, the power generation of the wind turbine generator set can be increased at low wind speeds during the grid-connected speed control stage. The low wind speed refers to a wind speed lower than the rated wind speed. In addition, the control method of the wind turbine generator set provided in the embodiment of the present application does not require the hardware equipment of the wind turbine generator set to be modified or updated, and can adjust the pitch angle at a low cost, thereby accelerating the grid-connected speed of the wind turbine generator set.

[0186] Based on the control method of a wind turbine generator set provided by the above method embodiment, the embodiment of the present application also provides a control device of a wind turbine generator set, and the control device of the wind turbine generator set will be described below in conjunction with the accompanying drawings.

[0187] See also Fig.16 As shown in FIG. 1 , this figure is a schematic diagram of the structure of a control device for a wind turbine generator set provided in an embodiment of the present application. Fig.16 As shown, the control device of the wind turbine generator set includes:

[0188] The first acquisition module 1601 is used to acquire the operating parameters of the wind turbine generator set, wherein the operating parameters include the impeller speed and the motor torque;

[0189] The second acquisition module 1602 is used to acquire the control parameter when it is determined that the operating parameter meets the control condition, and the control condition is used to determine that the wind turbine generator set is in the grid-connected speed control stage;

[0190] The third acquisition module 1603 is used to acquire a first corresponding relationship between the control parameter and the pitch angle;

[0191] A determination module 1604 is used to determine target pitch angle data corresponding to the control parameter according to the control parameter and a first corresponding relationship between the control parameter and the pitch angle;

[0192] The control module 1605 is used to control the wind turbine generator set according to the target pitch angle data.

[0193] Optionally, the third acquisition module 1603 is used to acquire a first corresponding relationship between a control parameter and a pitch angle, including:

[0194] The third acquisition module 1603 is used to obtain the second corresponding relationship between the tip speed ratio, the control parameter and the pitch angle; obtain the value of the tip speed ratio; and determine the first corresponding relationship between the control parameter and the pitch angle based on the second corresponding relationship and the value of the tip speed ratio.

[0195] Optionally, the third acquisition module 1603 is used to acquire a second corresponding relationship between the tip speed ratio, the control parameter and the pitch angle, including:

[0196] The third acquisition module 1603 is used to determine the third corresponding relationship between the tip speed ratio, the power coefficient of the wind turbine generator set and the pitch angle; determine the fourth corresponding relationship between the power coefficient of the wind turbine generator set and the control parameter; and determine the second corresponding relationship between the tip speed ratio, the control parameter and the pitch angle based on the third corresponding relationship and the fourth corresponding relationship.

[0197] Optionally, the third acquisition module 1603 is used to determine a second corresponding relationship between the tip speed ratio, the control parameter, and the pitch angle according to the third corresponding relationship and the fourth corresponding relationship, including:

[0198] The third acquisition module 1603 is used to determine the second corresponding relationship between the tip speed ratio, the control parameter and the pitch angle according to the third corresponding relationship and the fourth corresponding relationship when the power coefficient of the wind turbine generator set meets a predetermined condition.

[0199] Optionally, the predetermined condition is that the power coefficient of the wind turbine generator set is greater than or equal to a power coefficient threshold.

[0200] Optionally, the third acquisition module 1603 is used to acquire the value of the tip speed ratio, including:

[0201] The third acquisition module 1603 is used to acquire the wind speed, the impeller speed of the wind turbine generator set and the impeller radius of the wind turbine generator set; and determine the value of the tip speed ratio according to the impeller speed, the wind speed and the impeller radius.

[0202] Optionally, the first correspondence between the control parameter and the pitch angle includes a plurality of sub-correspondences, and the sub-correspondences include correspondences between control parameters belonging to a sub-value range and a numerical value of a pitch angle.

[0203] Optionally, the control condition is that the difference between the impeller speed and the minimum impeller speed threshold is less than or equal to the difference threshold, and the motor torque is less than the grid-connected control torque threshold.

[0204] Optionally, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between shaft power and the pitch angle;

[0205] Alternatively, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between the motor torque and the pitch angle;

[0206] Alternatively, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between wind speed and the pitch angle.

[0207] Based on a control method for a wind turbine generator set provided by the above method embodiment, the present application provides a device, including: a processor, a memory, and a system bus;

[0208] The processor and the memory are connected via the system bus;

[0209] The memory is used to store one or more programs, and the one or more programs include instructions. When the instructions are executed by the processor, the processor executes the control method of the wind turbine generator set described in any of the above embodiments.

[0210] Based on a control method for a wind turbine generator set provided in the above method embodiment, the present application provides a computer-readable storage medium, in which instructions are stored. When the instructions are executed on a terminal device, the terminal device executes the control method for a wind turbine generator set described in any of the above embodiments.

[0211] Based on the control method of a wind turbine generator set provided by the above method embodiment, the embodiment of the present application also provides a computer program product. The computer program product may be a software or program product containing instructions that can be run on a computing device or stored in any available medium. When the computer program product is run on at least one computing device, the at least one computing device executes the control method of the wind turbine generator set.

[0212] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system or device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0213] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0214] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0215] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0216] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a wind turbine generator set, characterized in that: The method comprises: Acquire operating parameters of the wind turbine generator set, wherein the operating parameters include impeller speed and motor torque; When it is determined that the operating parameter satisfies the control condition, obtaining the control parameter, wherein the control condition is used to determine that the wind turbine generator set is in the grid-connected speed control stage; Acquire a first corresponding relationship between a control parameter and a pitch angle; Determining target pitch angle data corresponding to the control parameter according to the control parameter and a first corresponding relationship between the control parameter and the pitch angle; The wind turbine generator set is controlled according to the target pitch angle data.

2. The method according to claim 1, characterized in that The obtaining of a first corresponding relationship between a control parameter and a pitch angle comprises: obtaining a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle; Get the value of the tip speed ratio; A first corresponding relationship between a control parameter and a pitch angle is determined according to the second corresponding relationship and the value of the tip speed ratio.

3. The method according to claim 2, characterized in that The obtaining of a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle comprises: determining a third correspondence between the tip speed ratio, the power coefficient of the wind turbine generator set and the pitch angle; Determining a fourth corresponding relationship between the power coefficient of the wind turbine generator set and the control parameter; According to the third corresponding relationship and the fourth corresponding relationship, a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle is determined.

4. The method according to claim 3, characterized in that Determining the second corresponding relationship among the tip speed ratio, the control parameter, and the pitch angle according to the third corresponding relationship and the fourth corresponding relationship includes: When the power coefficient of the wind turbine generator set meets a predetermined condition, a second corresponding relationship among the tip speed ratio, the control parameter and the pitch angle is determined according to the third corresponding relationship and the fourth corresponding relationship.

5. The method according to claim 4, characterized in that The predetermined condition is that the power coefficient of the wind turbine generator set is greater than or equal to a power coefficient threshold.

6. The method according to claim 2, characterized in that The step of obtaining the value of the tip speed ratio comprises: Obtaining wind speed, impeller speed of the wind turbine generator set, and impeller radius of the wind turbine generator set; The value of the tip speed ratio is determined according to the impeller rotation speed, the wind speed and the impeller radius.

7. The method according to claim 1, characterized in that The first correspondence between the control parameter and the pitch angle includes a plurality of sub-correspondences, wherein the sub-correspondences include correspondences between control parameters belonging to a sub-value range and a value of a pitch angle.

8. The method according to any one of claims 1 to 7, characterized in that: The control condition is that the difference between the impeller speed and the minimum impeller speed threshold is less than or equal to the difference threshold, and the motor torque is less than the grid-connected control torque threshold.

9. The method according to any one of claims 1 to 7, characterized in that: The first corresponding relationship between the control parameter and the pitch angle is the first corresponding relationship between the shaft power and the pitch angle; Alternatively, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between the motor torque and the pitch angle; Alternatively, the first corresponding relationship between the control parameter and the pitch angle is a first corresponding relationship between wind speed and the pitch angle.

10. An electronic device, characterized in that: include: one or more processors; a storage device having one or more programs stored thereon, When the one or more programs are executed by the one or more processors, the one or more processors implement the control method of the wind turbine generator set as described in any one of claims 1-9.

11. A computer program product, characterized in that When the computer program product is run on a device, the device executes the control method for a wind turbine generator set according to any one of claims 1 to 9.

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