Wind turbine generator system and method for pitch control of wind turbine generator system under wind shear wind condition

Abstract

The wind turbine generator set wind shear wind condition variable pitch control method and the wind turbine generator set provided by the present disclosure include: determining a first characteristic quantity of a wind speed of a first wind of a rotor of a wind turbine generator set and a second characteristic quantity of a wind speed of a second wind of the rotor based on wind speed data; determining a first trend quantity of the first characteristic quantity and a second trend quantity of the second characteristic quantity respectively; determining a wind shear wind condition between the first wind and the second wind based on the first trend quantity and the second trend quantity; and performing variable pitch control on the wind turbine generator set based on the wind shear wind condition. The wind turbine generator set wind shear wind condition variable pitch control method and the wind turbine generator set according to the present disclosure solve the problem of lacking identification and unit control in the wind shear wind condition, can perform variable pitch control on the wind turbine generator set based on the wind shear wind condition, and timely deal with the extreme load problem and the clearance problem, thereby ensuring the safety of the unit.

Description

Technical Field

[0001] This disclosure relates to the field of wind power generation, and more specifically, to a pitch control method and generator set for a wind turbine generator set under wind shear conditions. Background Technology

[0002] As the rotor diameter and overall capacity of wind turbine generators increase, the constraints on overall cost also increase. The headroom or ultimate load of wind turbine generators become important influencing factors in the development process, especially under extreme wind shear conditions.

[0003] However, the relevant technologies lack identification methods and corresponding unit control strategies related to wind shear conditions. This makes it impossible to effectively solve the headroom problem or ultimate load problem of wind turbine generators when facing wind shear conditions, thus affecting the safety and reliability of the units. Summary of the Invention

[0004] In view of the lack of identification and unit control under wind shear conditions in related technologies, this disclosure provides a pitch control method and generator set for wind turbine generator sets under wind shear conditions.

[0005] The first aspect of this disclosure provides a pitch control method for a wind turbine generator set under wind shear conditions. The pitch control method includes: determining a first characteristic quantity of the wind speed of a first incoming wind at the rotor of the wind turbine generator set and a second characteristic quantity of the wind speed of a second incoming wind at the rotor based on wind speed data; determining a first trend quantity of the first characteristic quantity and a second trend quantity of the second characteristic quantity, wherein the first trend quantity represents the cumulative amount of change of the first characteristic quantity within a preset time period before the first incoming wind reaches the rotor, and the second trend quantity represents the cumulative amount of change of the second characteristic quantity within the preset time period; determining the wind shear conditions between the first incoming wind and the second incoming wind based on the first trend quantity and the second trend quantity; and performing pitch control on the wind turbine generator set based on the wind shear conditions.

[0006] Optionally, the first trend quantity and the second trend quantity are determined by: determining the first trend quantity based on the cumulative amount of the first characteristic quantity within the preset time period and the cumulative amount of the first initial value of the first characteristic quantity within the preset time period; determining the second trend quantity based on the cumulative amount of the second characteristic quantity within the preset time period and the cumulative amount of the second initial value of the second characteristic quantity within the preset time period, wherein the first initial value is the first characteristic quantity at a specific moment within the preset time period, and the second initial value is the second characteristic quantity at a specific moment within the preset time period.

[0007] Optionally, determining the wind shear conditions between the first incoming wind and the second incoming wind based on the first trend quantity and the second trend quantity includes: determining a first difference quantity between the first characteristic quantity and the second characteristic quantity based on the cumulative amount of the first characteristic quantity within the preset time period and the cumulative amount of the second characteristic quantity within the preset time period; and determining the wind shear conditions based on the first trend quantity, the second trend quantity, and the first difference quantity.

[0008] Optionally, determining the wind shear condition based on the first trend quantity, the second trend quantity, and the first difference quantity includes: determining a second difference quantity between the first trend quantity and the second trend quantity; determining a wind shear parameter based on the first difference quantity and the second difference quantity, wherein the wind shear parameter characterizes the degree of wind shear between the first incoming wind and the second incoming wind; and determining the wind shear condition based on the wind shear parameter.

[0009] Optionally, both the first difference and the second difference can be positive, or both the first difference and the second difference can be negative.

[0010] Optionally, determining the wind shear condition between the first incoming wind and the second incoming wind based on the first trend quantity and the second trend quantity includes: determining the existence of wind shear condition in response to the first trend quantity satisfying a first preset condition, the first trend quantity satisfying a second preset condition, and the first difference quantity satisfying a third preset condition, or in response to the first difference quantity satisfying the third preset condition within a preset time length after the first trend quantity satisfies the first preset condition and the first trend quantity satisfies the second preset condition, wherein the first preset condition indicates that the cumulative amount of change of the first characteristic quantity exceeds the design trend boundary of the wind turbine generator set within the preset time period; the second preset condition indicates that the cumulative amount of change of the second characteristic quantity exceeds the design trend boundary of the wind turbine generator set within the preset time period; and the third preset condition indicates that the difference between the first characteristic quantity and the second characteristic quantity exceeds the design difference boundary of the wind turbine generator set, wherein the value of the design trend boundary of the first preset condition and the value of the design trend boundary of the second preset condition are opposite numbers to each other.

[0011] Optionally, pitch control of the wind turbine generator set is performed by: determining an additional pitch angle based on the wind shear conditions and wind speed-related quantities, wherein the wind speed-related quantities are parameters related to the wind speed currently experienced by the wind turbine generator set; and performing pitch control of the wind turbine generator set based on the additional pitch angle.

[0012] Optionally, the first feature quantity and the second feature quantity are determined by: acquiring wind speed data at multiple points along multiple paths from the incoming wind side to the impeller using an anemometer; determining the composite wind speed on each path at the current moment based on the wind speed data, the direction of each path, the distance of each of the multiple points from the impeller, and the wind speed processing parameters on the impeller at the current moment, wherein the wind speed processing parameters are determined based on the first feature quantity and the second feature quantity at the previous moment; and determining the first feature quantity and the second feature quantity at the current moment based on the composite wind speed on each path at the current moment.

[0013] Optionally, pitch control of the wind turbine generator set is performed in the following manner: based on the first characteristic quantity and the second characteristic quantity, a wind speed characteristic quantity of the wind in front of the rotor is determined; based on the degree to which the wind speed characteristic quantity deviates from the rated wind speed of the wind turbine generator set, an additional pitch angle is determined; based on the additional pitch angle, pitch control of the wind turbine generator set is performed, wherein the degree to which the wind speed characteristic quantity deviates from the rated wind speed is negatively correlated with the additional pitch angle.

[0014] Optionally, determining the additional pitch angle based on the degree to which the wind speed characteristic deviates from the rated wind speed of the wind turbine includes: determining multiple wind speed ranges and candidate additional pitch angles corresponding to each wind speed range based on the rated wind speed, cut-in wind speed, cut-out wind speed of the wind turbine and a preset correction value; and determining the candidate additional pitch angle corresponding to the wind speed range satisfied by the wind speed characteristic as the additional pitch angle.

[0015] Optionally, the plurality of wind speed ranges include a first wind speed range, a second wind speed range, and a third wind speed range. The first wind speed range is determined based on a preset correction value and the rated wind speed, and includes the rated wind speed. The second wind speed range is determined based on the cut-in wind speed of the wind turbine generator and the first wind speed range, and is less than the first wind speed range. The third wind speed range is determined based on the cut-out wind speed of the wind turbine generator and the first wind speed range, and is greater than the first wind speed range. The candidate additional pitch angle corresponding to the first wind speed range is greater than the candidate additional pitch angle corresponding to the third wind speed range and the candidate additional pitch angle corresponding to the first wind speed range.

[0016] A second aspect of this disclosure provides a computer device comprising: at least one processor; and at least one memory storing computer-executable instructions, wherein, when executed by the at least one processor, the computer-executable instructions cause the at least one processor to perform a pitch control method for a wind turbine generator under wind shear conditions according to an embodiment of this disclosure.

[0017] A third aspect of this disclosure provides a wind turbine generator set, the wind turbine generator set including computer equipment according to embodiments of this disclosure.

[0018] A fourth aspect of this disclosure provides a computer-readable storage medium that, when instructions in the computer-readable storage medium are executed by at least one processor, causes the at least one processor to perform a pitch control method for a wind turbine generator under wind shear conditions according to embodiments of this disclosure.

[0019] According to the pitch control method and generator set of the wind turbine generator set under wind shear conditions disclosed herein, the characteristic quantities of different incoming wind speeds of the rotor can be determined based on wind speed data, and their respective trend quantities can be determined according to the characteristic quantities of different incoming wind speeds. The trend quantity can characterize the cumulative amount of change of the characteristic quantity of wind speed over a period of time. Based on such trend quantity, the wind shear conditions can be judged more accurately, and thus the pitch control of the wind turbine generator set can be performed based on the wind shear conditions to deal with ultimate load problems and clearance problems in a timely manner and ensure the safety of the unit. Attached Figure Description

[0020] Figure 1 This is a schematic flowchart illustrating a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0021] Figure 2 This is a schematic flowchart illustrating the steps of determining a first characteristic quantity and a second characteristic quantity in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0022] Figure 3 This is a schematic diagram illustrating the acquisition of wind speed data in a pitch control method for a wind turbine generator under wind shear conditions, according to an exemplary embodiment of the present disclosure.

[0023] Figure 4 This is a schematic flowchart illustrating the steps of determining the composite wind speed in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0024] Figure 5 This is a schematic diagram illustrating the changing trend of positive shear wind conditions in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0025] Figure 6 This is a schematic diagram illustrating the negative shear wind condition variation trend in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0026] Figure 7This is a schematic flowchart illustrating an example of the steps in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0027] Figure 8 This is a schematic flowchart illustrating another example of the steps in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0028] Figure 9 This is a schematic flowchart illustrating an example of the pitch control steps in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0029] Figure 10 This is a schematic diagram illustrating fuzzy control based on average wind speed and trend quantity in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0030] Figure 11 This is a schematic diagram illustrating fuzzy control based on pitch angle and trend quantity in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0031] Figure 12 This is a schematic architecture diagram illustrating another example of the pitch control steps in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0032] Figure 13 This is a schematic flowchart illustrating the steps of determining an additional pitch angle in a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure.

[0033] Figure 14 This is a schematic diagram illustrating the nonlinear relationship between wind speed and additional pitch angle in a pitch control method for a wind turbine generator under wind shear conditions, according to an exemplary embodiment of the present disclosure.

[0034] Figure 15 This is a schematic diagram showing a comparison of blade root loads under wind shear conditions using a pitch control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure and without a pitch control method.

[0035] Figure 16 This is a schematic diagram showing a comparison of the clearance under wind shear conditions using a pitch control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure with that without using a pitch control method.

[0036] Figure 17This is a schematic diagram showing a comparison of the nacelle acceleration of a wind turbine generator under wind shear conditions using a pitch control method according to an exemplary embodiment of the present disclosure and without a pitch control method. Detailed Implementation

[0037] The following detailed embodiments are provided to aid the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein, but may be changed as will become clear upon understanding this disclosure, except for operations that must occur in a specific order. Furthermore, for clarity and conciseness, descriptions of features known in the art may be omitted.

[0038] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein, which will become clear upon understanding the disclosure of this application.

[0039] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more.

[0040] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts should not be limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Thus, without departing from the teaching of the examples described herein, the first component, first assembly, first region, first layer, or first part referred to as the first component, first assembly, first region, first layer, or first part may also be referred to as the second component, second assembly, second region, second layer, or second part.

[0041] In the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to," or "bonded to" another element, the element may be directly "on" another element, directly "connected to," or "bonded to" the other element, or one or more other elements may be present in between. Conversely, when an element is described as being "directly on" another element, "directly connected to," or "directly bonded to" another element, no other elements may be present in between.

[0042] The terminology used herein is for the purpose of describing various examples only and is not intended to limit disclosure. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. The terms “comprising,” “including,” and “having” indicate the presence of the described features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0043] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains upon understanding this disclosure. Unless expressly defined herein, terms (such as those defined in a general dictionary) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field and in this disclosure, and shall not be interpreted in an idealized or overly formalistic manner.

[0044] Furthermore, in the description of the examples, detailed descriptions of well-known related structures or functions will be omitted when it is believed that such detailed descriptions would lead to a vague interpretation of this disclosure.

[0045] As mentioned above, the lack of identification methods and corresponding unit control strategies for wind shear conditions in related technologies means that the headroom or ultimate load problems of wind turbine generators under wind shear conditions cannot be effectively solved, affecting the safety and reliability of the units.

[0046] In view of the above problems, this disclosure provides a pitch control method for a wind turbine generator set under wind shear conditions, a computer device, a wind turbine generator set, and a computer-readable storage medium to solve or at least alleviate the above problems.

[0047] According to a first aspect of an exemplary embodiment of the present disclosure, a pitch control method for a wind turbine generator under wind shear conditions is provided. This pitch control method for the wind turbine generator can be executed by an electronic device with computational analysis capabilities. The electronic device can be a terminal device or a server, wherein the terminal device can be, for example, a tablet computer, a laptop computer, a digital assistant, etc.; the server can be a standalone server, a server cluster, a cloud computing platform, or a virtualization center.

[0048] In an example application scenario, an electronic device executing a pitch control method for a wind turbine generator under wind shear conditions according to embodiments of the present disclosure can determine a first characteristic quantity of the wind speed of a first incoming wind at the rotor of the wind turbine generator and a second characteristic quantity of the wind speed of a second incoming wind at the rotor based on wind speed data, and can respectively determine a first trend quantity of the first characteristic quantity and a second trend quantity of the second characteristic quantity. Here, the first trend quantity represents the cumulative amount of change of the first characteristic quantity within a preset time period before the first incoming wind reaches the rotor, and the second trend quantity refers to the cumulative amount of change of the second characteristic quantity within a preset time period before the second incoming wind reaches the rotor.

[0049] The electronic device can also determine the wind shear conditions between the first and second incoming winds based on the first and second trend values, and can perform pitch control on the wind turbine based on the wind shear conditions.

[0050] Here, the electronic device can, for example, communicate with a database or data management system that stores measured or estimated wind speed data, so that the electronic device can perform the above-described method based on the wind speed data.

[0051] According to the pitch control scheme of the wind turbine generator disclosed herein, wind shear conditions can be judged more accurately, and pitch control of the wind turbine generator can be performed based on the wind shear conditions to deal with extreme load and clearance issues in a timely manner and ensure the safety of the generator.

[0052] A pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of the present disclosure may include the following steps:

[0053] like Figure 1 As shown, in step S110, based on wind speed data, a first characteristic quantity of the wind speed of the first incoming wind at the rotor of the wind turbine generator set and a second characteristic quantity of the wind speed of the second incoming wind at the rotor can be determined.

[0054] In this step, wind speed data can be obtained by measuring wind using wind measuring devices such as lidar, millimeter-wave ranging radar, microwave radar, and acoustic radar. However, the embodiments of this disclosure are not limited to this, and wind speed data can also be obtained by other devices or methods, such as by estimation using machine learning models or empirical models.

[0055] The first and second incoming airflows can originate from different positions on the impeller. For example, the first incoming airflow can be from the upper side of the impeller, and the second incoming airflow can be from the lower side of the impeller; or, the first incoming airflow can be from the right side of the impeller, and the second incoming airflow can be from the left side of the impeller. However, it is not limited to these. For example, the first incoming airflow can also be from the upper right side of the impeller, and the second incoming airflow can be from the lower left side of the impeller.

[0056] The characteristic quantity of wind speed can characterize the properties of wind speed. For example, it can be obtained by reconstructing the wind speed of the corresponding incoming wind based on wind speed data, such as the equivalent wind speed.

[0057] As an example, the first and second eigenvalues ​​can be determined in the following way:

[0058] like Figure 2 As shown, in step S210, wind speed data at multiple points along multiple paths from the incoming wind side to the impeller can be obtained based on the wind measuring device.

[0059] As wind blows from the incoming side to the impeller, the wind speed may vary. Here, we can obtain the wind speed at multiple points along multiple paths pointing towards the impeller, allowing for a more three-dimensional and accurate analysis of wind speed trends. These multiple paths can have different directions.

[0060] For example, such as Figure 3 As shown, taking a four-beam pulse lidar as an example, the wind measurement device can simultaneously measure wind speed data at multiple range gates. It can acquire the wind speed of each beam at multiple range gates. For example, four paths S1, S2, S3, and S4 formed by the four beams can be selected, and the wind speed at two range gates on each path can be measured respectively. For instance, points P11 and P12 on path S1, points P21 and P22 on path S2, points P31 and P32 on path S3, and points P41 and P42 on path S4. Thus, points P11, P21, P31, and P41 can be in the same plane, and points P12, P22, P32, and P42 can also be in the same plane.

[0061] It should be noted that although the above example uses four paths and two points on each path to obtain wind speed data, the embodiments disclosed herein are not limited to this. More or fewer paths can be selected, and / or more or fewer points can be selected on each path.

[0062] In step S220, the composite wind speed on each path at the current moment can be determined based on the wind speed data, the direction of each path, the distance of each point from the impeller, and the wind speed processing parameters on the impeller at the current moment.

[0063] In this step, in one example, the wind speed processing parameters on the impeller at the current moment can be determined based on the first and second characteristic quantities at the previous moment, for example, the average of the first and second characteristic quantities at the previous moment. In the example of determining the wind speed processing parameters based on the first and second characteristic quantities, a temporal correlation of wind speed can be established, making the obtained wind speed processing parameters more consistent with the actual wind speed change trend and better reflect the wind speed characteristics on the impeller.

[0064] Here, the wind speed processing parameters at the initial moment can be estimated or measured using other methods, such as by measuring them with an anemometer installed at or near the impeller.

[0065] In another example, the wind speed processing parameters at any given moment on the impeller can be obtained by measuring an anemometer installed at or near the impeller.

[0066] The wind speed processing parameter can be, for example, the average wind speed, but it is not limited to this. It can also be other wind speed parameters that can characterize the wind speed at the impeller, such as the equivalent wind speed of the entire impeller.

[0067] As an example, the direction of each path can be represented by the angle between the path and the horizontal line, but it is not limited to this and can also be represented in other ways, such as the angle with the vertical line, the angle with another path, vector coordinates, etc. Specifically, the direction of the path can be arbitrary. For example, the direction of the beam emitted by the lidar can be divergent. When calculating the composite wind speed, the direction of the path can be converted to a direction perpendicular to the impeller surface. Therefore, the direction of the path can be represented by the angle between the path and the horizontal line perpendicular to the impeller surface.

[0068] The distance from each point to the impeller can be, for example, the distance from the point to the impeller, which can be read at an anemometer.

[0069] In step S220, based on wind speed data, the direction of each path, the distance of each point from the impeller, and the wind speed processing parameters on the impeller at the current moment, the wind speed at each point on each path can be synthesized to obtain the composite wind speed on the path. This composite wind speed can, for example, represent the average wind speed at each point on the path when it reaches the impeller.

[0070] As an example, for each path, the composite wind speed can be determined in the following way:

[0071] like Figure 4 As shown, in step S410, the target time corresponding to each point can be determined based on the wind speed processing parameters on the impeller at the current moment and the distance of each point from the impeller among multiple points.

[0072] In this step, the target time corresponding to each point represents the moment when the wind moving towards the nearest measurement point is located at that point at the current moment. Here, the nearest measurement point is the point closest to the impeller among multiple points on each path. Specifically, the wind is constantly moving, and the wind blowing towards the nearest measurement point at the current moment would have passed through points on the aforementioned path at previous target times. This target time is related to the distance from that point to the nearest measurement point and the wind speed. As an example, the nearest measurement point could be on the distance gate closest to the impeller, and the distance between each point and the nearest measurement point could be the distance between the distance gate where that point is located and the distance gate closest to the impeller.

[0073] Taking the average wind speed on the impeller at the current moment as the wind speed processing parameter as an example, the distance from each point to the nearest measurement point can be divided by the average wind speed to obtain the time it takes for the wind to travel from that point to the nearest measurement point. Thus, the target time can be calculated based on the current moment and the travel time.

[0074] For example, with Figure 3 For example, based on the distance x from point P12 to the impeller j The distance x1 from the nearest measurement point and the average wind speed of the impeller. The time Δt required for the wind to travel from point P12 to the impeller can be determined. 12 ,Right now Therefore, based on the current time t, the target time can be determined as (t-Δt). 12 By doing so, the target time corresponding to each point on each path can be determined.

[0075] In step S420, the wind speed measurement data at each point at the corresponding target time can be determined based on the wind speed data.

[0076] Given a target time for each point, the wind speed at that point at the target time can be extracted from the wind speed data. For example, it could be RAWS. ij (t-Δt ij ).

[0077] In step S430, the composite wind speed can be determined based on the wind speed measurement data of each point at the corresponding target time and the direction of each path.

[0078] As an example, if the wind speed at all points on the path at the corresponding target time is obtained, the average wind speed at these points in a specific direction can be calculated.

[0079] For example, the composite wind speed of the i-th path at the current moment can be represented by the following equation (1).

[0080]

[0081] Where i represents the path number, for example, for a four-beam radar, i can take the values ​​1, 2, 3, or 4; j represents the point number on the path, for example, it can be the range gate number; θ i The represents the direction of the i-th path, for example, the angle between the path and the horizontal line; t represents the current time; x j x1 represents the measured distance of the j-th point, for example, the measured distance of the j-th distance gate; x1 represents the measured distance of the 1st point; u represents the wind speed processing parameters at the current moment, for example, the average wind speed at the current moment; RAWS ij (x) represents the wind speed measured at time x at the j-th point on the i-th path along the path direction, and n represents the number of points on the path, such as the number of distance gates.

[0082] Here, because the wind speed in front of the impeller is measured in real time using wind measuring equipment, and the wind speed can be converted to the measurement distance of the first point, risky wind conditions can be identified in advance, so that the pitch can be adjusted in advance, making the pitch protection control more effective.

[0083] By determining the composite wind speed in the above manner, the wind speed at multiple points along each path can be comprehensively considered to determine the total composite wind speed of that path. This reflects the wind speed status along the entire path, making subsequent wind speed calculations more accurate.

[0084] In step S230, the first and second characteristic quantities at the current time can be determined based on the synthetic wind speed on each path at the current time.

[0085] In this step, the composite wind speeds of each path can be used to determine the first and second characteristic quantities. Specifically, as mentioned above, each composite wind speed can reflect the wind speed state on the corresponding path. When the composite wind speeds of multiple paths are obtained, these composite wind speeds can be further fused to obtain the first characteristic quantity of the first incoming wind and the second characteristic quantity of the second incoming wind.

[0086] In the example where the first incoming airflow is from the upper side of the impeller and the second incoming airflow is from the lower side of the impeller, taking... Figure 3 For example, based on the measurement orientation corresponding to the number of each path, assuming that paths S1 and S2 represent two paths on the upper side of the impeller, and paths S3 and S4 represent two paths on the lower side of the impeller, we can obtain, for example, a first characteristic quantity of the equivalent wind speed on the upper side of the impeller and a second characteristic quantity of the equivalent wind speed on the lower side of the impeller.

[0087] Specifically, the first characteristic quantity U can be represented by the following equations (2) and (3). high Second characteristic quantity U low :

[0088]

[0089]

[0090] In the example where the first incoming airflow is from the left side of the impeller and the second incoming airflow is from the right side of the impeller, taking... Figure 3 For example, based on the measurement orientation corresponding to the number of each path, assuming that paths S1 and S4 represent two paths on the left side of the impeller, and paths S2 and S3 represent two paths on the right side of the impeller, we can obtain, for example, a first characteristic quantity of the equivalent wind speed on the left side of the impeller and a second characteristic quantity of the equivalent wind speed on the right side of the impeller.

[0091] Specifically, the first characteristic quantity U can be represented by the following equations (4) and (5). left Second characteristic quantity U right :

[0092]

[0093]

[0094] As described above, the first and second characteristic quantities of the desired location can be reconstructed based on wind speed data. The first and second characteristic quantities obtained by the wind speed reconstruction method can better reflect the wind speed status at the corresponding location, making the prediction of wind speed more accurate and thus improving the unit control effect.

[0095] Although an example of wind speed reconstruction has been given above, it is not limited to this. Other wind speed reconstruction methods can be used depending on the measurement location and method of the wind speed data.

[0096] Furthermore, although the method of obtaining the first and second features through wind speed reconstruction is described above, the determination of the first and second features is not limited to this. For example, the first and second features can be obtained by using the wind speed data of the first and second incoming winds through methods such as difference and fitting.

[0097] In step S120, the first trend quantity of the first characteristic quantity and the second trend quantity of the second characteristic quantity can be determined respectively.

[0098] Here, the first trend quantity can represent the cumulative amount of change of the first characteristic quantity within a preset time period before the first incoming wind reaches the impeller, and the second trend quantity can represent the cumulative amount of change of the second characteristic quantity within the preset time period.

[0099] Wind shear (also known as wind shear) is an atmospheric phenomenon that represents the change of a wind vector with wind direction and speed over equal horizontal and / or vertical distances in the air. Wind shear can include positive and negative shear. Wind shear conditions include positive and negative shear conditions in the horizontal direction, as well as positive and negative shear conditions in the vertical direction.

[0100] For example, vertical wind shear can refer to the change of wind vector over vertical distance in the air. Negative vertical shear can be characterized by wind speed values ​​at lower distances being greater than those at higher distances, while positive vertical shear can be characterized by wind speed values ​​at higher distances being greater than those at lower distances. Horizontal wind shear can refer to the change of wind vector over horizontal distance in the air. Negative horizontal shear can be characterized by wind speed values ​​on one horizontal side (e.g., left or right) being greater than those on the other horizontal side (e.g., right or left), while positive horizontal shear can be characterized by wind speed values ​​on one horizontal side being less than those on the other horizontal side.

[0101] Since local wind speeds may increase or decrease rapidly in a short period of time under wind shear conditions, extreme wind shear conditions can be identified more accurately and timely by calculating the cumulative changes of the first and second characteristic quantities over a period of time, so as to take timely unit control strategies.

[0102] As an example, the first trend quantity and the second trend quantity can be determined in the following ways: the first trend quantity can be determined based on the cumulative amount of the first characteristic quantity within a preset time period and the cumulative amount of the first initial value of the first characteristic quantity within a preset time period; the second trend quantity can be determined based on the cumulative amount of the second characteristic quantity within a preset time period and the cumulative amount of the second initial value of the second characteristic quantity within a preset time period.

[0103] Here, the first initial value can be a first feature value at a specific moment within a preset time period, and the second initial value can be a second feature value at a specific moment within the preset time period. The length of the preset time period can be determined according to actual needs, and the specific moment can be, for example, the initial moment of the preset time period.

[0104] Specifically, the change in the cumulative amount of a feature quantity (such as a first feature quantity or a second feature quantity) over a preset time period can be determined based on the difference between the cumulative amount of the feature quantity over the preset time period and the cumulative amount of the feature quantity at the initial moment of the preset time period over the preset time period.

[0105] For example, Figure 5 Example curves of wind speed versus time under positive shear wind conditions are shown, such as... Figure 5 As shown, if the current time is t0 and the initial time of the preset time period is (t0-Δt), then the length of the preset time period is Δt.

[0106] In this case, taking the first incoming airflow as the airflow coming from the upper side of the impeller and the second incoming airflow as the airflow coming from the lower side of the impeller as an example, the first trend quantity S high It can be expressed by the following equation (6):

[0107]

[0108] Among them, U high (t) represents the first characteristic quantity. U represents the cumulative amount of the first characteristic quantity within a preset time period. high (t0-Δt)×Δt represents the first initial value U of the first characteristic quantity. high0 The cumulative amount within a preset time period.

[0109] Reference Figure 5 The curve shown can be considered as the difference between the area under the curve of the first characteristic quantity within a preset time period (i.e., the area formed by the curve and the horizontal axis within the preset time period) and the area accumulated by the first characteristic quantity at the initial moment over the preset time period (i.e., the rectangular area formed by the size of the first characteristic quantity at the initial moment and the length of the preset time period).

[0110] Similarly, the second trend quantity S low It can be expressed by the following equation (7):

[0111]

[0112] Among them, U low (t) represents the second characteristic quantity. U represents the cumulative amount of the second characteristic quantity over a preset time period. low (t0-Δt)-Δt represents the second initial value U of the second characteristic quantity. low0 The cumulative amount within a preset time period.

[0113] Reference Figure 5 The curve shown can be considered as the area accumulated by the second characteristic quantity at the initial time over a preset time period (i.e., the rectangular area formed by the magnitude of the second characteristic quantity at the initial time and the length of the preset time period) and the area on the curve of the second characteristic quantity within the preset time period (i.e., the area between the curve and the second initial value U within the preset time period). low0 The difference in the area formed.

[0114] Figure 6 Example wind speed versus time curves under negative shear wind conditions are shown. Although the areas representing the first and second trend quantities are not shown, it can be understood that they are similar to those described above. Figure 5 The representation and calculation methods are similar, so they will not be repeated here.

[0115] Furthermore, in the example where the first incoming airflow is from the left side of the impeller and the second incoming airflow is from the right side of the impeller, the first trend quantity and the second trend quantity can have similar representations to the above equations (6) and (7), for example, as shown in the following equations (8) and (9):

[0116]

[0117]

[0118] Among them, U left (t) represents the first characteristic quantity. U represents the cumulative amount of the first characteristic quantity within a preset time period. left (t0-Δt)×Δt represents the cumulative amount of the first initial value of the first characteristic quantity within a preset time period; U right (t) represents the second characteristic quantity. U represents the cumulative amount of the second characteristic quantity over a preset time period. right (t0-Δt)×Δt represents the cumulative amount of the second initial value of the second characteristic quantity within a preset time period.

[0119] By using the above method to determine the trend quantity by the difference between two cumulative quantities, the change of wind speed from the moment of the sudden change (such as the initial moment mentioned above) can be reflected. The base wind speed that already exists at the moment of the sudden change can be eliminated. This means that no matter what the base wind speed is, the focus is always on the relative magnitude of the cumulative change of wind speed characteristic quantity, avoiding the difference in wind shear wind condition identification caused by different base wind speeds, and thus more accurately identifying extreme wind shear wind conditions.

[0120] In step S130, the wind shear conditions between the first incoming wind and the second incoming wind can be determined based on the first trend quantity and the second trend quantity.

[0121] In this step, after determining the first trend quantity and the second trend quantity, since the first trend quantity and the second trend quantity respectively represent the cumulative changes of characteristic quantities of the first and second incoming winds within a preset time period, the wind shear conditions between the current first and second incoming winds can be identified by comparing the first trend quantity and the second trend quantity.

[0122] As an example, step S130 may include the following steps:

[0123] like Figure 7 As shown, in step S710, the first difference between the first feature and the second feature can be determined based on the cumulative amount of the first feature within a preset time period and the cumulative amount of the second feature within a preset time period.

[0124] Specifically, the cumulative amount of the first characteristic quantity and the cumulative amount of the second characteristic quantity can represent the cumulative wind energy of the first incoming wind and the cumulative wind energy of the second incoming wind, respectively. By determining the difference between the two, the energy difference between the incoming winds at different positions on the impeller can be judged, thereby more accurately determining the degree of wind shear.

[0125] Based on the above Figure 5Taking equations (6) to (9) as examples, in the example where the first incoming air is the air coming from the upper side of the impeller and the second incoming air is the air coming from the lower side of the impeller, the cumulative amount of the first characteristic quantity within the preset time period can be expressed as follows: The cumulative amount of the second characteristic quantity over a preset time period can be expressed as: In this case, the first difference quantity S v_diff It can be expressed by the following formula (10):

[0126]

[0127] Similarly, in the example where the first incoming airflow is from the left side of the impeller and the second incoming airflow is from the right side of the impeller, the cumulative amount of the first characteristic quantity within a preset time period can be expressed as: The cumulative amount of the second characteristic quantity over a preset time period can be expressed as: In this case, the first difference quantity S h diff It can be expressed by the following formula (11):

[0128]

[0129] In step S720, the wind shear condition can be determined based on the first trend quantity, the second trend quantity, and the first difference quantity.

[0130] Here, the first trend quantity and the second trend quantity can respectively characterize the accumulation of wind energy of the first and second incoming winds, and the first difference quantity can represent the difference between the accumulation of wind energy of the two. Knowing these three parameters, it can be considered that the absolute wind conditions of the first and second incoming winds, as well as the relative wind conditions between them, are understood. Therefore, a suitable wind shear condition identification method can be selected according to actual needs. Several examples of wind shear condition identification according to embodiments of this disclosure will be given below.

[0131] In one example, in step S720, preset conditions can be set for the first trend quantity, the second trend quantity, and the first difference quantity. When the corresponding preset conditions are met, it can be considered that extreme wind shearing conditions may have occurred.

[0132] For example, the existence of wind shearing conditions can be determined in response to the first trend quantity satisfying the first preset condition, the second trend quantity satisfying the second preset condition, and the first difference quantity satisfying the third preset condition, or in response to the first difference quantity satisfying the third preset condition within a preset time period after the first trend quantity satisfies the first preset condition and the second trend quantity satisfies the second preset condition.

[0133] Here, the first preset condition can indicate that the cumulative change of the first characteristic quantity within a preset time period exceeds the design trend boundary of the wind turbine generator set; the second preset condition can indicate that the cumulative change of the second characteristic quantity within a preset time period exceeds the design trend boundary of the wind turbine generator set; the third preset condition can indicate that the difference between the first characteristic quantity and the second characteristic quantity exceeds the design difference boundary of the wind turbine generator set, wherein the value of the design trend boundary of the first preset condition can be the opposite of the value of the design trend boundary of the second preset condition.

[0134] Since wind shear conditions include positive and negative shear conditions in the horizontal direction and positive and negative shear conditions in the vertical direction, as an example, preset conditions can be set for different wind shear conditions respectively.

[0135] As an example, in positive shear conditions, such as vertical positive shear conditions and horizontal positive shear conditions, the identification of wind shear can be illustrated by taking the extreme positive shear conditions in the extreme wind shear (EWS) conditions specified in the IEC-61400-1 standard.

[0136] The first preset condition can be that the first trend quantity is greater than the trend boundary, the second preset condition can be that the second trend quantity is less than the opposite of the trend boundary, and the third preset condition can be that the first difference quantity is greater than the difference boundary.

[0137] For example, for vertical positive shear wind conditions, a trend boundary S can be set. b_vp and difference boundary S d_vp Both of these boundary parameters are positive. The above three preset conditions can be judged, specifically, as follows:

[0138]

[0139] If the above three preset conditions are met simultaneously, or if the first and second preset conditions are met simultaneously and the third preset condition is met within a future time period T, then it can be determined as a vertical positive shear wind condition.

[0140] Similarly, for horizontal positive shear wind conditions, a trend boundary S can be set. b_hp and difference boundary S d_hp Both of these boundary parameters are positive. The above three preset conditions can be judged, specifically, as follows:

[0141]

[0142] If all three preset conditions are met simultaneously, or if the first and second preset conditions are met simultaneously and the third preset condition is met within a future time period T, then it can be determined as a horizontal positive shear wind condition.

[0143] As an example, in negative shear wind conditions, such as vertical negative shear wind conditions and horizontal negative shear wind conditions, the identification of wind shear can be illustrated by taking the extreme negative shear wind conditions in the EWS wind conditions specified in the IEC-61400-1 standard.

[0144] The first preset condition can be that the first trend quantity is less than the opposite of the trend boundary; the second preset condition can be that the second trend quantity is greater than the trend boundary; and the third preset condition can be that the first difference quantity is less than the opposite of the difference boundary.

[0145] For example, for vertical negative shear wind conditions, a trend boundary S can be set. b_vn and difference boundary S d_vn Both of these boundary parameters are positive. The above three preset conditions can be judged, specifically, as follows:

[0146]

[0147] If the above three preset conditions are met simultaneously, or if the first and second preset conditions are met simultaneously and the third preset condition is met within a future time period T, then it can be determined as a vertical negative shear wind condition.

[0148] Similarly, for horizontal negative shear wind conditions, a trend boundary S can be set. b_hn and difference boundary S d_hn Both of these boundary parameters are positive. The above three preset conditions can be judged, specifically, as follows:

[0149]

[0150] If all three preset conditions are met simultaneously, or if the first and second preset conditions are met simultaneously and the third preset condition is met within a future time period T, then it can be determined as a horizontal negative shear wind condition.

[0151] In the above example, the time length T can be set according to actual needs. As an example, it can be defined according to the IEC 61400-1 international standard. In the IEC 61400-1 international standard, the change period of the extreme wind shear model is 12 seconds. Therefore, the time length T can be set to 12 seconds.

[0152] By using the above-mentioned preset conditions to judge wind shear conditions, we can comprehensively judge wind shear conditions from two aspects: two trend quantities and the difference between the two trend quantities, so as to make the identification of wind shear conditions more accurate.

[0153] Alternatively or alternatively, in another example, the wind shear conditions can be determined in step S720 by the following method:

[0154] like Figure 8 As shown, in step S810, a second difference between the first trend quantity and the second trend quantity can be determined.

[0155] The above describes determining the first difference quantity based on the first feature quantity and the second feature quantity. Here, the second difference quantity can also be determined based on the first trend quantity, the second trend quantity, and the first difference quantity.

[0156] As mentioned above Figure 5 Taking equations (6) to (9) as examples, in the example where the first incoming air is the air coming from the upper side of the impeller and the second incoming air is the air coming from the lower side of the impeller, the first trend quantity can be expressed as S. high The second trend quantity can be represented as S. low In this case, the second difference can be expressed as (S high -S low ).

[0157] Similarly, in the example where the first incoming airflow is from the left side of the impeller and the second incoming airflow is from the right side of the impeller, the first trend quantity can be represented as S. left The second trend quantity can be represented as S. right In this case, the second difference can be expressed as (S left -S right ).

[0158] In step S820, wind shear parameters can be determined based on the first difference and the second difference.

[0159] Here, the wind shear parameter can characterize the degree of wind shear between the first and second incoming winds.

[0160] As mentioned above Figure 5 Taking equations (6) to (9) as examples, in the example where the first incoming air is the air coming from the upper side of the impeller and the second incoming air is the air coming from the lower side of the impeller, the wind shear parameter S v It can be expressed by the following formula (12):

[0161] S v =(S high -S low )×S v_diff (12)

[0162] Similarly, in the example where the first incoming airflow is from the left side of the impeller and the second incoming airflow is from the right side of the impeller, the wind shear parameter S... h It can be expressed by the following formula (13):

[0163] S h =(S left -S right )×S h_diff (13)

[0164] In step S830, the wind shear conditions can be determined based on the wind shear parameters.

[0165] In this step, boundary conditions can be preset for the wind shear parameters. If the wind shear parameters meet the boundary conditions, the wind shear condition can be determined.

[0166] For example, different boundary conditions can be set for vertical wind shear and horizontal wind shear. Specifically, for the vertical wind shear condition, the wind shear parameter S... v Greater than the first boundary condition S vb In this case, it can be determined as a vertical wind shearing wind condition; for a horizontal wind shearing wind condition, under the wind shear parameter S h Greater than the second boundary condition S hb In this case, it can be determined as a horizontal wind shearing condition.

[0167] As an example, the boundary conditions preset for the wind shear parameters can be related to the length Δt of the preset time period mentioned above, and the value of the boundary conditions can have a non-linear positive correlation with the length Δt of the preset time period.

[0168] Furthermore, as an example, both the first and second differences can be positive, or both can be negative. In this way, when calculating the wind shear parameter, the possibility of a negative wind shear parameter can be eliminated by the same sign relationship between the first and second differences, ensuring that the wind shear parameter is always positive.

[0169] For example, for vertical positive shear wind conditions, the first trend quantity S high Greater than 0, second trend quantity S low Less than 0, therefore, the first difference quantity S v_diff The wind shear parameter S is greater than 0. v Greater than 0; for vertical negative shear wind conditions, the first trend quantity S high Less than 0, second trend quantity S low The first difference is greater than 0, therefore, the first difference is S. v_diff The wind shear parameter S is less than 0. v It is also greater than 0. The same applies to horizontal positive shear wind conditions and horizontal negative shear wind conditions.

[0170] In this way, the same identification method can be used to identify positive and negative shear wind conditions, simplifying the identification logic of the wind condition identification process. For example, the number of thresholds can be reduced, and only one threshold as a positive value can be set to determine the magnitude of the wind shear parameter.

[0171] Based on the above method for identifying wind shear conditions, the energy accumulation process can be considered through integration. Furthermore, by transforming wind shear parameters, the wind shear parameters for positive and negative wind conditions can be unified, thereby unifying the identification methods for positive and negative wind conditions and reducing the number of parameters.

[0172] It should be noted that although the calculation expressions of each parameter are shown in this article as examples, such as the above equations (1) to (13), they are not limited to the above examples. For example, other calculation methods can be used to calculate, or the above expressions can be modified, scaled, etc.

[0173] In step S140, pitch control of the wind turbine generator can be performed based on wind shear conditions.

[0174] In this step, when wind shear conditions are identified, pitch control can be used to achieve pitch control of the unit to alleviate the ultimate load problem and clearance problem under wind shear conditions.

[0175] The embodiments disclosed below provide several examples of pitch control of wind turbine generators based on wind shear conditions.

[0176] In one example, pitch control of a wind turbine generator can be performed in the following ways: Figure 9 As shown, in step S910, the additional pitch angle can be determined based on the wind shear wind condition and wind speed correlation; in step S920, the wind turbine generator can be pitch controlled based on the additional pitch angle.

[0177] Here, wind speed related quantities can be parameters related to the wind speed currently experienced by the wind turbine generator, such as average wind speed, pitch angle, etc., but they are not limited to these. Wind speed related quantities are used to characterize the magnitude or trend of wind speed. Parameters obtained by statistical or other processing of wind speed, or parameters that have a corresponding relationship with wind speed, can all be used as wind speed related quantities.

[0178] In this step, pitch control can be performed based on two dimensions. Specifically, on the one hand, since the load and headroom results of wind turbine generators differ under different levels of wind shear conditions, the aforementioned wind shear parameter S... v Japanese wind shear parameter S h For example, wind shear parameter S v Japanese wind shear parameter Sh The larger the value, the greater the impact on the load and headroom of the wind turbine generator set; on the other hand, pitch control is also affected by the wind speed factor currently experienced by the wind turbine generator set. Therefore, in this example, the pitch control of the generator set can be carried out from a two-dimensional perspective using the concept of fuzzy control.

[0179] For example, such as Figure 10 As shown, in one dimension, wind shear conditions can be expressed through the wind shear parameter S. v With the first boundary condition S vb The difference (S) v -S vb and wind shear parameter S h With the second boundary condition S hb The difference (S) h -S hb ) is used to represent this.

[0180] Here, we can use the wind shear parameter S v Greater than the first boundary condition S vb The degree (S) v -S vb The wind shear parameter is greater than the second boundary condition S. hb The degree (S) h -S hb To dynamically adjust the additional pitch angle Δθ, in (S v -S vb ) or (S h -S hb When the pitch angle Δθ is less than or equal to 0, the additional pitch angle Δθ can be 0. However, it is not limited to this; wind shear conditions can also be determined by the wind shear parameter S. v Japanese wind shear parameter S h This indicates that, in this case, the wind shear parameter S v Less than or equal to the first boundary condition S vb and wind shear parameter S h Less than or equal to the second boundary condition S hb In this case, the additional pitch angle Δθ can be 0.

[0181] In addition, on another dimension, the wind speed-related quantity can be the average wind speed, and the additional pitch angle Δθ can be dynamically adjusted based on the average wind speed experienced by the current wind turbine.

[0182] For example, such as Figure 11 As shown, in one dimension, wind shear conditions can be expressed through the wind shear parameter S. v With the first boundary condition S vb The difference (S) v -S vb and wind shear parameter S h With the second boundary condition Shb The difference (S) h -S hb ) is used to represent this.

[0183] Furthermore, on another dimension, the wind speed-related quantity can be the pitch angle, which can be dynamically adjusted based on the current pitch angle value of the wind turbine. Here, the pitch angle is positively correlated with the current wind speed in the control of the wind turbine; therefore, the higher the wind speed, the larger the pitch angle. Thus, in this example, the pitch angle can be used as a wind speed-related quantity.

[0184] In the examples above, when the wind speed is near the rated wind speed, the issues of load and headroom may be particularly prominent. Therefore, as Figure 10 and Figure 11 As shown, when the average wind speed is close to the rated wind speed, or when the wind speed corresponding to the pitch angle is close to the rated wind speed, the additional pitch angle Δθ is relatively large, i.e., as... Figure 10 and Figure 11 The peak range of the additional pitch angle Δθ.

[0185] Given a determined additional pitch angle Δθ, this additional pitch angle Δθ can be superimposed on the final pitch requirement of the wind turbine generator set. For example, it can be superimposed on the pitch angle determined by other control programs, thereby achieving the purpose of load reduction and clearance protection under wind shear conditions.

[0186] In another example, pitch control of a wind turbine generator can be performed in the following way:

[0187] like Figure 12 As shown, in step S1210, the wind speed characteristic of the wind coming from in front of the impeller can be determined based on the first characteristic and the second characteristic.

[0188] As an example, the wind speed characteristic quantity can be the average wind speed of the wind coming from in front of the impeller, for example, the average of the first characteristic quantity and the second characteristic quantity can be used as the wind speed characteristic quantity.

[0189] In step S1220, the additional pitch angle can be determined based on the degree to which the wind speed characteristic quantity deviates from the rated wind speed of the wind turbine generator set.

[0190] Because the impact of wind shearing on the unit varies under different wind speed conditions, generally speaking, the load reduction effect of control is more demanding near the rated wind speed. Therefore, the additional pitch angle can be determined based on the degree to which the wind speed characteristic deviates from the rated wind speed of the wind turbine.

[0191] Here, the degree to which the wind speed characteristic deviates from the rated wind speed can be negatively correlated with the additional pitch angle. When the wind speed characteristic is near the rated wind speed, the additional pitch angle can be larger.

[0192] As an example, in step S1220, the additional pitch angle can be determined in the following way:

[0193] like Figure 13 As shown, in step S1310, multiple wind speed ranges and candidate additional pitch angles corresponding to each wind speed range can be determined based on the rated wind speed, cut-in wind speed, cut-out wind speed of the wind turbine generator set and preset correction values.

[0194] In step S1320, the candidate additional pitch angle corresponding to the wind speed range satisfied by the wind speed characteristic quantity can be determined as the additional pitch angle.

[0195] Here, multiple wind speed ranges can be defined for the wind speed characteristic, and different preset candidate additional pitch angles can be corresponding to different ranges.

[0196] As an example, multiple wind speed ranges may include a first wind speed range, a second wind speed range, and a third wind speed range. The first wind speed range can be determined based on a preset correction value and the rated wind speed, and includes the rated wind speed. The second wind speed range can be determined based on the cut-in wind speed of the wind turbine and the first wind speed range, and is lower than the first wind speed range. The third wind speed range can be determined based on the cut-out wind speed of the wind turbine and the first wind speed range, and is higher than the first wind speed range. Here, the preset correction value can be determined according to actual needs or empirical methods to determine the first wind speed range near the rated wind speed.

[0197] Here, the candidate additional pitch angle corresponding to the first wind speed range can be greater than the candidate additional pitch angle corresponding to the third wind speed range and the candidate additional pitch angle corresponding to the first wind speed range. In this way, a larger additional pitch angle can be used when the wind speed conditions are close to the rated wind speed, thereby improving the load reduction effect of pitch control.

[0198] Based on the above division of wind speed ranges, a nonlinear relationship curve between wind speed characteristic quantities and additional pitch angle can be established, which can be represented by the following equation (14):

[0199]

[0200] Where V0L represents the wind speed characteristic quantity, V cutin V represents the cut-in wind speed of the wind turbine generator. rated V represents the rated wind speed of the wind turbine generator set. cutout This represents the cut-out wind speed of the wind turbine generator, v1 represents the preset first correction value, v2 represents the preset second correction value, θ represents the current pitch angle of the generator, θ0 represents the first pitch angle boundary, for example, it can be the minimum pitch angle of the generator, θ1 represents the second pitch angle boundary, and Δθ maxThis represents the maximum additional pitch requirement. Here, the second pitch angle boundary θ1 can be determined based on the pitch angle value when there is no risk to the overall load or clearance, without enabling the identification and protection scheme. The maximum additional pitch requirement Δθ max For example, it can be in the range of [0,5], with the unit being degrees (deg). Although Equation (14) shows the values ​​of the additional pitch angle in each wind speed range, it is not limited to this and can be set according to the actual situation.

[0201] As an example, the first correction value v1 and the second correction value v2 can be based on the experience of whole machine development, such as v1∈[2,5], v2∈[2,5], and their unit can be meters per second (m / s). In addition, the first correction value and the second correction value can be the same or different, for example, v1=3m / s and v2=5m / s.

[0202] Furthermore, based on the rated wind speed of the wind turbine generator set, the location of the wind speed at which the load problem and / or clearance problem occurs can be found. A first correction value v1 and a second correction value v2 can then be set based on this wind speed location to ensure that the wind speed location is included in a first wind speed range. For example, with a rated wind speed of 10 m / s, if a load problem occurs at a wind speed of 7 m / s, v1 can be set to 4 m / s to identify and control wind speeds within a specific range. The second correction value v2 is determined in the same way.

[0203] For example, at the cut-in wind speed V cutin 3m / s, rated wind speed V rated 10 m / s, cut-out wind speed V cutout In the example with a speed of 20 m / s, a first correction value v1 of 3 m / s, and a second correction value v2 of 5 m / s, it can be specifically as follows: Figure 14 The curves showing the nonlinear relationship between wind speed characteristics and additional pitch angle are shown.

[0204] Using the above method, the additional pitch angle can be determined according to wind speed conditions, and pitch control can be performed to provide more precise load protection and clearance protection under wind shear conditions.

[0205] In step S1230, pitch control of the wind turbine generator can be performed based on the additional pitch angle.

[0206] After determining the additional pitch angle, the blades of the wind turbine can be controlled to perform a pitch-retracting action at a certain pitch rate, controlling the pitch angle of the three blades from the current pitch angle θ to the position θ+Δθ. After reaching the θ+Δθ position, the pitch angle of the wind turbine can be restricted, preventing the turbine from performing pitch-opening action, until the wind shearing condition is experienced and passes through the rotor surface of the wind turbine.

[0207] Using the above method, when wind shear conditions are identified, the additional pitch angle can be determined based on the wind speed conditions to perform pitch control. Since the wind speed change trend is obtained in advance through the trend quantity, this control method has a time lead, which can effectively reduce the ultimate load of the wind turbine and alleviate headroom.

[0208] Figure 15 , Figure 16 and Figure 17 The effects of using a pitch control method for a wind turbine generator under wind shear conditions according to exemplary embodiments of the present disclosure are compared with those without the use of a pitch control method.

[0209] Compared to not employing pitch control, when using the method according to exemplary embodiments of this disclosure, such as Figure 15 As shown, this can reduce the load on the unit; such as Figure 16 As shown, this can increase the headroom; as Figure 17 As shown, this can reduce nacelle acceleration, thereby improving the stability of the unit.

[0210] The pitch control method for wind turbine generators under wind shear conditions according to the embodiments of this disclosure can accurately identify wind shear conditions, and under extreme wind shear conditions, the pitch control of the wind turbine generator can be used to protect the overall airspace, reduce the risk of blades sweeping the tower, and reduce the ultimate load of the wind turbine generator.

[0211] According to a second aspect of this disclosure, a computer device is provided, the computer device comprising: at least one processor; at least one memory storing computer-executable instructions, wherein the computer-executable instructions, when executed by the at least one processor, cause the at least one processor to perform the pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of this disclosure.

[0212] As an example, computer equipment can be installed in the wind turbine generator set, or the computer equipment can be connected to the control system of the wind turbine generator set.

[0213] As an example, a computer device can be a PC, tablet, personal digital assistant, smartphone, or other device capable of executing the aforementioned set of instructions. Here, a computer device is not necessarily a single electronic device, but can be any collection of devices or circuits capable of executing the aforementioned instructions (or instruction sets) individually or in combination. A computer device can also be part of an integrated control system or system manager, or can be configured to interface with a portable electronic device locally or remotely (e.g., via wireless transmission).

[0214] In computer devices, a processor may include a central processing unit (CPU), a graphics processing unit (GPU), a programmable logic device, a dedicated processor system, a microcontroller, or a microprocessor. By way of example and not limitation, a processor may also include an analog processor, a digital processor, a microprocessor, a multi-core processor, a processor array, a network processor, etc.

[0215] The processor can execute instructions or code stored in memory, which can also store data. Instructions and data can also be sent and received over a network via a network interface device, which can employ any known transport protocol.

[0216] Memory can be integrated with the processor; for example, RAM or flash memory can be housed within an integrated circuit microprocessor. Alternatively, memory can comprise a separate device, such as an external disk drive, storage array, or other storage device that can be used by any database system. Memory and processor can be operatively coupled, or can communicate with each other, for example, via I / O ports, network connections, etc., enabling the processor to read files stored in the memory.

[0217] In addition, computer equipment may include video displays (such as liquid crystal displays) and user interaction interfaces (such as keyboards, mice, touch input devices, etc.). All components of a computer device may be interconnected via buses and / or networks.

[0218] According to a third aspect of this disclosure, a wind turbine generator set is provided, which may include the computer equipment described in embodiments of this disclosure.

[0219] According to a fourth aspect of this disclosure, a computer-readable storage medium is provided that, when instructions in the computer-readable storage medium are executed by at least one processor, causes the at least one processor to perform a pitch control method for a wind turbine generator under wind shear conditions according to an exemplary embodiment of this disclosure.

[0220] The pitch control method for a wind turbine generator under wind shear conditions according to embodiments of this disclosure can be programmed into a computer program and stored on a computer-readable storage medium. Examples of computer-readable storage media include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disc storage, hard disk drive (HDD), solid-state drive (SSD), card storage (such as multimedia cards, secure digital (SD) cards, or ultra-fast digital (XD) cards), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, and any other device configured to store a computer program and any associated data, data files, and data structures in a non-transitory manner and to provide the computer program and any associated data, data files, and data structures to a processor or computer so that the processor or computer can execute the computer program. In one example, the computer program and any associated data, data files, and data structures are distributed across a networked computer system, such that the computer program and any associated data, data files, and data structures are stored, accessed, and executed in a distributed manner through one or more processors or computers.

[0221] The specific embodiments of this disclosure have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that modifications and variations can be made to these embodiments without departing from the principles and spirit of this disclosure, which are defined by the claims and their equivalents. Such modifications and variations should also be within the protection scope of the claims of this disclosure.

Claims

1. A pitch control method for a wind turbine generator set under wind shear conditions, characterized in that, The pitch control method includes: Based on wind speed data, a first characteristic quantity of the wind speed of the first incoming wind at the rotor of the wind turbine generator set and a second characteristic quantity of the wind speed of the second incoming wind at the rotor are determined. A first trend quantity of the first characteristic quantity and a second trend quantity of the second characteristic quantity are determined respectively, wherein the first trend quantity represents the cumulative amount of change of the first characteristic quantity during a preset time period before the first incoming wind reaches the impeller, and the second trend quantity represents the cumulative amount of change of the second characteristic quantity during the preset time period before the second incoming wind reaches the impeller. Based on the first trend quantity and the second trend quantity, the wind shear conditions between the first incoming wind and the second incoming wind are determined; Based on the wind shear conditions, pitch control is applied to the wind turbine generator set.

2. The pitch control method according to claim 1, characterized in that, The first trend quantity and the second trend quantity are determined in the following manner: The first trend quantity is determined based on the cumulative amount of the first feature quantity within the preset time period and the cumulative amount of the first initial value of the first feature quantity within the preset time period. The second trend quantity is determined based on the cumulative amount of the second characteristic quantity within the preset time period and the cumulative amount of the second initial value of the second characteristic quantity within the preset time period. Wherein, the first initial value is a first feature value at a specific moment within the preset time period, and the second initial value is a second feature value at a specific moment within the preset time period.

3. The pitch control method according to claim 1, characterized in that, The step of determining the wind shear conditions between the first incoming wind and the second incoming wind based on the first trend quantity and the second trend quantity includes: Based on the cumulative amount of the first feature quantity and the cumulative amount of the second feature quantity within the preset time period, a first difference quantity between the first feature quantity and the second feature quantity is determined; The wind shear condition is determined based on the first trend quantity, the second trend quantity, and the first difference quantity.

4. The pitch control method according to claim 3, characterized in that, Determining the wind shear condition based on the first trend value, the second trend value, and the first difference value includes: Determine a second difference between the first trend quantity and the second trend quantity; Based on the first difference and the second difference, wind shear parameters are determined, wherein the wind shear parameters characterize the degree of wind shear between the first incoming wind and the second incoming wind; Based on the wind shear parameters, the wind shear conditions are determined.

5. The pitch control method according to claim 4, characterized in that, Both the first difference and the second difference are positive, or both the first difference and the second difference are negative.

6. The pitch control method according to claim 3, characterized in that, The step of determining the wind shear conditions between the first incoming wind and the second incoming wind based on the first trend quantity and the second trend quantity includes: In response to the first trend quantity satisfying a first preset condition, the second trend quantity satisfying a second preset condition, and the first difference quantity satisfying a third preset condition, or in response to the first difference quantity satisfying the third preset condition within a preset time period after the first trend quantity satisfies the first preset condition and the second trend quantity satisfies the second preset condition, it is determined that a wind shearing condition exists. Wherein, the first preset condition means that the cumulative amount of change of the first characteristic quantity within the preset time period exceeds the design trend boundary of the wind turbine generator set. The second preset condition indicates that the cumulative change of the second characteristic quantity within the preset time period exceeds the design trend boundary of the wind turbine generator set; The third preset condition indicates that the difference between the first characteristic quantity and the second characteristic quantity exceeds the design difference boundary of the wind turbine generator set. Wherein, the value of the design trend boundary of the first preset condition is the opposite of the value of the design trend boundary of the second preset condition.

7. The pitch control method according to claim 1, characterized in that, The wind turbine generator set is pitch controlled in the following manner: Based on the wind shear conditions and wind speed correlation, the additional pitch angle is determined, wherein the wind speed correlation is a parameter related to the wind speed currently experienced by the wind turbine generator set; Based on the additional pitch angle, pitch control is performed on the wind turbine generator set.

8. The pitch control method according to claim 1, characterized in that, The first feature and the second feature are determined in the following manner: Wind speed data at multiple points along multiple paths from the incoming wind side to the impeller are obtained using an anemometer. Based on the wind speed data, the direction of each path, the distance of each of the plurality of points from the impeller, and the wind speed processing parameters on the impeller at the current moment, the composite wind speed on each path at the current moment is determined, wherein the wind speed processing parameters are determined based on the first feature quantity and the second feature quantity at the previous moment. Based on the synthetic wind speed on each path at the current time, the first feature quantity and the second feature quantity at the current time are determined.

9. The pitch control method according to claim 1, characterized in that, The wind turbine generator set is pitch controlled in the following manner: Based on the first feature quantity and the second feature quantity, the wind speed feature quantity of the wind coming in front of the impeller is determined; The additional pitch angle is determined based on the degree to which the wind speed characteristic deviates from the rated wind speed of the wind turbine generator set; Based on the additional pitch angle, pitch control is performed on the wind turbine generator set. The degree to which the wind speed characteristic deviates from the rated wind speed is negatively correlated with the additional pitch angle.

10. The pitch control method according to claim 9, characterized in that, The step of determining the additional pitch angle based on the degree to which the wind speed characteristic deviates from the rated wind speed of the wind turbine generator includes: Based on the rated wind speed, cut-in wind speed, cut-out wind speed and preset correction value of the wind turbine generator set, multiple wind speed ranges and candidate additional pitch angles corresponding to each wind speed range are determined. The candidate additional pitch angle corresponding to the wind speed range satisfied by the wind speed characteristic quantity is determined as the additional pitch angle.

11. The pitch control method according to claim 10, characterized in that, The multiple wind speed ranges include a first wind speed range, a second wind speed range, and a third wind speed range. The first wind speed range is determined based on a preset correction value and the rated wind speed, and includes the rated wind speed; The second wind speed range is determined based on the cut-in wind speed of the wind turbine generator and the first wind speed range, and is smaller than the first wind speed range; The third wind speed range is determined based on the cut-out wind speed of the wind turbine generator and the first wind speed range, and is greater than the first wind speed range. Among them, the candidate additional pitch angle corresponding to the first wind speed range is greater than the candidate additional pitch angle corresponding to the third wind speed range and the candidate additional pitch angle corresponding to the first wind speed range.

12. A computer device, characterized in that, include: At least one processor; At least one memory that stores computer-executable instructions. Wherein, when the computer-executable instructions are executed by the at least one processor, the at least one processor causes the at least one processor to execute the pitch control method for wind turbine generators under wind shear conditions as described in any one of claims 1-11.

13. A wind turbine generator set, characterized in that, The wind turbine generator set includes the computer equipment according to claim 12.

14. A computer-readable storage medium, characterized in that, When the instructions in the computer-readable storage medium are executed by at least one processor, the at least one processor causes the at least one processor to perform the pitch control method for wind turbine generators under wind shear conditions as described in any one of claims 1-11.

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