Variable pitch control method of wind generating set and wind generating set

Abstract

The invention provides a variable pitch control method of a wind generating set and the wind generating set, and the variable pitch control method comprises the following steps: determining the wind speed data of a plurality of positions on each blade of the wind generating set based on the wind speed data of the incoming flow side of the wind generating set; based on the wind speed data of the multiple positions, equivalent wind speed data of each blade is determined; based on the equivalent wind speed data of each blade, determining the wind speed difference between different directions of the impeller surface; and according to the wind speed difference, variable pitch control is conducted on the wind generating set. According to the variable-pitch control method of the wind generating set and the wind generating set, the problem that load reduction cannot be carried out in time due to the fact that the sensing capacity for uneven wind conditions is poor is solved, the wind speed condition in the whole impeller face can be sensed, variable-pitch control and timely load reduction are carried out, and the safety and stability of operation of the wind generating set are ensured.

Description

Technical Field

[0001] The present disclosure relates to the field of wind power generation, and more particularly, to a pitch control method for a wind turbine generator set and a wind turbine generator set. Background Art

[0002] With the enlargement of wind turbine generator sets, the wind conditions endured by wind turbines during operation become more complex. The complex wind conditions may lead to an increase in the operating load of the wind turbine and a reduction in its operating life.

[0003] In the related art, a measuring device can be used to sense the oncoming wind speed in advance and perform corresponding pitch actions to reduce the operating load of the wind turbine. This method can only sense the overall change in wind speed, for example, whether there are significant differences in the upper and lower sides or the left and right sides of the wind speed in the vertical or horizontal directions. However, this method has poor sensing ability for continuous non-uniform wind conditions. For example, although the differences in the upper and lower sides or the left and right sides of the wind speed in the vertical or horizontal directions are not obvious, the distribution of the wind speed in the vertical or horizontal direction is actually non-uniform. Therefore, when facing non-uniform wind speeds such as this situation, the load reduction effect of the above method is poor. Summary of the Invention

[0004] In view of the problem that the related art has poor sensing ability for non-uniform wind conditions and thus cannot perform load reduction in a timely manner, the present disclosure provides a pitch control method for a wind turbine generator set and a wind turbine generator set.

[0005] The first aspect of the present disclosure provides a pitch control method for a wind turbine generator set. The pitch control method includes: determining wind speed data at multiple positions on each blade of the wind turbine generator set based on the wind speed data on the oncoming flow side of the wind turbine generator set; determining the equivalent wind speed data of each blade based on the wind speed data at the multiple positions; determining the wind speed difference between different azimuths on the impeller plane based on the equivalent wind speed data of each blade; and performing pitch control on the wind turbine generator set according to the wind speed difference.

[0006] Optionally, the wind speed data on the oncoming flow side includes the spatial point wind speeds of multiple spatial points in the same plane on the oncoming flow side. For each position on each blade, the wind speed data at each position is determined by the following method: determining the wind speed data at the current position based on the positional relationship between the multiple spatial points and the current position and the spatial point wind speeds of the multiple spatial points.

[0007] Optionally, the wind speed data at the current position is determined as follows: based on the spatial point wind speeds of the target spatial points in multiple target directions among the multiple spatial points and the positional relationship between the current position and the target spatial points, determine the target wind speeds at the current position in each target direction; synthesize the target wind speeds in each target direction to determine the wind speed data at the current position.

[0008] Optionally, for each target direction, the target wind speed is determined as follows: based on the positional relationship between the current position and the target spatial point in this target direction, determine the corresponding position of the current position in this target direction; based on the positional relationship between the corresponding position and the target spatial point in this target direction, interpolate the spatial point wind speed of the target spatial point to obtain the target wind speed.

[0009] Optionally, the synthesizing the target wind speeds in each target direction to determine the wind speed data at the current position includes: based on the blade direction of the blade where the current position is located, which points from the impeller center to the blade tip, synthesize the target equivalent wind speeds in each target direction to determine the equivalent wind speed data at the current position.

[0010] Optionally, the equivalent wind speed data of each blade is determined as follows: accumulate the wind speed data at the multiple positions on the blade along the blade length of the blade in the blade direction from the impeller center to the blade tip to obtain a wind speed accumulation; based on the wind speed accumulation and the blade length, determine the equivalent wind speed data of the blade.

[0011] Optionally, the wind speed difference between different azimuths on the impeller surface is determined as follows: determine a first deviation between the equivalent wind speed data of every two blades, and use the first deviation as the wind speed difference; and / or, determine a second deviation between the time series data in the equivalent wind speed data of each blade, and use the second deviation as the wind speed difference.

[0012] Optionally, the pitch control of the wind turbine generator set is performed as follows: in response to the first deviation satisfying a preset first deviation condition and / or the second deviation satisfying a preset second deviation condition, determine the independent pitch angle of each blade; based on the independent pitch angle, perform pitch control on the wind turbine generator set.

[0013] Optionally, the pitch control method further includes: based on the rotation frequency of the impeller of the wind turbine generator set, screen the data in the equivalent wind speed data of each blade that is located in the frequency band where the rotation frequency is located to obtain the screened data; based on the screened data, determine the wind speed difference.

[0014] A second aspect of the present disclosure provides a computer device, which includes: at least one processor; and at least one memory storing computer-executable instructions, wherein when the computer-executable instructions are run by the at least one processor, the at least one processor is caused to execute the pitch control method of the wind turbine according to the embodiments of the present disclosure.

[0015] A third aspect of the present disclosure provides a wind turbine, which includes the computer device according to the embodiments of the present disclosure.

[0016] According to the pitch control method of the wind turbine and the wind turbine of the present disclosure, the wind speed data at multiple positions on each blade of the wind turbine can be determined, and the equivalent wind speed of each blade can be determined, so that the wind speed difference between different azimuths in the impeller plane can be determined. Based on this wind speed difference, the wind speed condition in the entire impeller plane can be sensed. Even in the face of uneven wind conditions, the load impact that the wind condition may bring can be sensed, so as to perform pitch control and reduce the load in a timely manner to ensure the safety and stability of the operation of the wind turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic flowchart showing the pitch control method of the wind turbine according to an exemplary embodiment of the present disclosure.

[0018] Figure 2 is a schematic diagram showing an example of obtaining wind speed data in the pitch control method of the wind turbine according to an exemplary embodiment of the present disclosure.

[0019] Figure 3 is a schematic diagram showing an example of calculating the wind speed at each position on the blade in the pitch control method of the wind turbine according to an exemplary embodiment of the present disclosure.

[0020] Figure 4 is a schematic flowchart showing the steps of determining the wind speed data at the current position in the pitch control method of the wind turbine according to an exemplary embodiment of the present disclosure.

[0021] Figure 5 is a schematic flowchart showing the steps of determining the target wind speed in the pitch control method of the wind turbine according to an exemplary embodiment of the present disclosure.

[0022] Figure 6 is a schematic diagram showing another example of calculating the wind speed at each position on the blade in the pitch control method of the wind turbine according to an exemplary embodiment of the present disclosure.

[0023] Figure 7It is a schematic diagram showing another example of calculating the wind speed at each position on a blade in the pitch control method of a wind turbine according to an exemplary embodiment of the present disclosure.

[0024] Figure 8 It is a flowchart showing the steps of determining the equivalent wind speed data of each blade in the pitch control method of a wind turbine according to an exemplary embodiment of the present disclosure.

[0025] Figure 9 It is a schematic diagram showing the determination of each distance on a blade in the pitch control method of a wind turbine according to an exemplary embodiment of the present disclosure.

[0026] Figure 10 It is a schematic diagram showing an example of pitch control based on the maximum deviation value in the pitch control method of a wind turbine according to an exemplary embodiment of the present disclosure.

[0027] Figure 11 It is a schematic diagram showing an example of pitch control based on the maximum wind speed standard deviation in the pitch control method of a wind turbine according to an exemplary embodiment of the present disclosure. Detailed Embodiments

[0028] The following detailed embodiments are provided to assist the reader in obtaining a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent after understanding the disclosure of the present application. For example, the order of operations described herein is merely exemplary and is not limited to those set forth herein, but rather may be changed as will be apparent after understanding the disclosure of the present application, except for operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for greater clarity and conciseness.

[0029] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Instead, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described herein, which will be apparent after understanding the disclosure of the present application.

[0030] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more thereof.

[0031] Although terms such as "first", "second", and "third" may be used herein to describe various components, elements, regions, layers, or sections, these components, elements, regions, layers, or sections should not be limited by these terms. Instead, these terms are only used to distinguish one component, element, region, layer, or section from another. Thus, a first component, first element, first region, first layer, or first section as referred to in the examples described herein may also be referred to as a second component, second element, second region, second layer, or second section without departing from the teachings of the examples.

[0032] In the specification, when an element (such as a layer, region, or substrate) is described as "on" another element, "connected to" or "coupled to" another element, the element can be directly "on" the other element, directly "connected to" or "coupled to" the other element, or there can be one or more other elements therebetween. In contrast, when an element is described as "directly on" another element, "directly connected to" or "directly coupled to" another element, there can be no other elements therebetween.

[0033] The terms used herein are only for describing various examples and are not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. The terms "comprising", "including", and "having" specify the presence of the stated 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.

[0034] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains after understanding this disclosure. Unless explicitly defined as such herein, terms (such as those defined in a general dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and should not be interpreted in an idealized or overly formal manner.

[0035] Furthermore, in the description of the examples, when a detailed description of related structures or functions that are considered well-known would cause an ambiguous interpretation of the disclosure, such detailed descriptions will be omitted.

[0036] As described above, in the related art, there are errors in the wind speed data used for the power characteristic verification of a wind turbine generator set, making it difficult to ensure the accuracy of the verification results.

[0037] As an example, in the related art, the techniques for reducing the operating load of a wind turbine generator can include radar feedforward control and independent pitch technology.

[0038] Radar feedforward control can sense the incoming wind speed in advance and make corresponding pitch actions to reduce the operating load of the wind turbine. This function has an obvious load reduction effect on the increase in load caused by the overall change of wind speed. However, it has a poor load reduction effect on persistent non-uniform wind conditions (such as vertical shear with wind speed magnitude distributed in a ">" or "<" shape).

[0039] In addition, the independent pitch technology controls the load of the wind turbine based on the root load of the blade, but this control relies on additional sensors and there is also a lag in feedback control in extreme cases.

[0040] In view of the above problems, the present disclosure provides a pitch control method for a wind turbine generator set, a wind turbine generator set and a computer device to solve or at least alleviate the above problems.

[0041] According to a first aspect of an exemplary embodiment of the present disclosure, there is provided a pitch control method for a wind turbine generator set. This pitch control method can be executed by a computer device with computing capabilities, for example, it can be executed by the pitch control system or the overall control system of the wind turbine generator set. The computer device executing this pitch control method can be, for example, a terminal device or a server. Among them, the terminal device can be, such as a tablet computer, a laptop computer, a digital assistant, etc.; the server can be an independent server, a server cluster, a cloud computing platform or a virtualization center.

[0042] In an example application scenario, the computer device can determine the wind speed data at multiple positions on each blade of the wind turbine generator set based on the wind speed data on the incoming flow side of the wind turbine generator set, and determine the equivalent wind speed data of each blade based on the wind speed data at the above multiple positions. The computer device can also determine the wind speed difference between different azimuths on the impeller plane based on the equivalent wind speed data of each blade, and perform pitch control on the wind turbine generator set according to the wind speed difference.

[0043] Here, the computer device can be, for example, set at the wind turbine generator set or the wind farm, and can be communicatively connected to, for example, the measuring device, the control system or the data center of the wind turbine generator set or the wind farm, so as to obtain data such as wind speed data and unit operation data required for executing the above method.

[0044] According to the pitch control method of the wind turbine generator set of the present disclosure, by determining the wind speed data at multiple positions on each blade of the wind turbine generator set, the equivalent wind speed of each blade can be determined, so that the wind speed difference between different azimuths in the impeller plane can be determined. Based on this wind speed difference, the wind speed situation in the entire impeller plane can be sensed. Even in the face of non-uniform wind conditions, the load impact that the wind conditions may bring can be sensed, and thus pitch control can be performed to reduce the load in a timely manner to ensure the safety and stability of the operation of the wind turbine generator set.

[0045] The pitch control method of a wind turbine generator set according to the present disclosure may include the following steps:

[0046] like Figure 1 As shown, in step S110, wind speed data at multiple positions on each blade of the wind turbine generator set may be determined based on the wind speed data on the incoming flow side of the wind turbine generator set.

[0047] In this step, the incoming flow of the wind turbine generator set may be the wind blowing toward the windward side of the impeller of the wind turbine generator set. The wind speed data on the incoming flow side may be directly measured by a wind speed measuring device such as a remote sensing measuring device, or may be predicted or estimated by a prediction device such as a wind farm wind speed prediction device based on the wind speed measured by the wind speed measuring device.

[0048] As an example, the wind speed data on the incoming flow side may include the spatial point wind speeds of multiple spatial points in the same plane on the incoming flow side. Figure 2 As shown, the inflow wind information at multiple spatial points in front of the wind turbine can be determined by a remote sensing measurement device such as a lidar or a wind farm wind speed prediction device. These spatial points can be distributed in multiple different cross-sections, and the distances between the multiple different cross-sections and the wind turbine can be different. For example, they can be located at 70 meters, 90 meters, and 100 meters in front of the wind turbine.

[0049] In this example, in step S110, for each position on each blade, the wind speed data of each position can be determined in the following manner: based on the positional relationship between multiple spatial points and the current position and the spatial point wind speeds of the multiple spatial points, the wind speed data of the current position is determined.

[0050] Specifically, when the wind speeds at multiple spatial points are known, the spatial position relationship between the current position of the wind speed to be determined and these spatial points can be mapped to the wind speed distribution relationship. Figure 3 As an example, based on the wind speed at multiple spatial points u11, u12, u21 and u22, the wind speed at these spatial points and the current position u θr The position relationship between them determines the current position u θr Here, the spatial points can be distributed at different heights and different horizontal directions in different cross sections, and the wind speed at each point is recorded as v ij For example, the spatial locations of the measurement points at a certain cross-sectional position are an i×j matrix, the horizontal spacing between each adjacent point is N, and the vertical distance between each adjacent point is M. In order to reduce the spatial locations of the measurement points, the cross measurement method can also be used to obtain the incoming wind speed at different heights and horizontal directions.

[0051] In this way, the correspondence from the spatial position relationship to the wind speed distribution can be achieved, so that the wind speed at any position within the impeller plane can be determined from the spatial units of several known wind speed data, and a more accurate assessment of the global wind conditions can be made.

[0052] As an example, in this step S110, the wind speed data at the current position can be determined in the following manner:

[0053] As Figure 4 shown, in step S410, based on the spatial point wind speeds of the target spatial points in multiple target directions among multiple spatial points and the positional relationship between the current position and the target spatial points, the target wind speeds at the current position in each target direction can be determined.

[0054] In this step, the target direction can be the direction formed by any two or more spatial points among multiple spatial points. For example, it can be the direction passing through the center of the current cross-section. However, it is not limited to this, and it can also be other spatial points. In Figure 3 the example, multiple target directions can include, for example, the first direction formed by spatial point u21 and spatial point u22, and the second direction formed by spatial point u12 and spatial point u22; or, for example, the first direction formed by spatial point u11 and spatial point u12, and the second direction formed by spatial point u11 and spatial point u21. In Figure 2 it, the radar measures the wind speeds at 9 spatial positions of 3×3 within the impeller plane. Among them, spatial points u11, u12, u21, and u22 are the 4 measurement points in the upper right relative to the hub center (here, the center of each measurement cross-section can correspond to the hub center on the rotation axis of the impeller), and the horizontal and vertical distances between adjacent measurement points can be equal.

[0055] As an example, multiple target directions can include two mutually perpendicular directions, such as the above-mentioned first direction and second direction, or, for example, the third direction formed by spatial point u11 and spatial point u12, and the fourth direction formed by spatial point u22 and spatial point u12.

[0056] The spatial points in the target direction can be used as the target spatial points, or in other words, the spatial points forming the target direction can be used as the target spatial points. For example, in the example of the above-mentioned first direction and second direction, the target spatial points include spatial points u21, u22, and u12. Although two target spatial points in each target direction are shown here, it is not limited to this, and more target spatial points can also be selected according to the actual measurement data. For example, one or more target spatial points can also be included between spatial point u21 and spatial point u22 and / or between spatial point u12 and spatial point u22, so as to refine the distribution of the spatial positions and use the wind speeds of these target spatial points to more accurately estimate the wind speed at the current position.

[0057] Given the spatial point wind speed at a known target spatial point and the positional relationship between the current position and the target spatial point, the positional relationship between the current position and the target spatial point in each target direction can be determined, thereby determining the wind speed distribution relationship in each target direction to determine the target wind speed at the current position in each target direction.

[0058] As an example, in this step S410, for each target direction, the target wind speed can be determined in the following manner:

[0059] As Figure 5 shown, in step S510, based on the positional relationship between the current position and the target spatial point in this target direction, the corresponding position of the current position in this target direction can be determined.

[0060] As an example, taking the example of Figure 3 , in the case where the target directions include the above-mentioned first direction and second direction, based on geometric methods, the current position u whose wind speed is to be determined θr can be projected onto the first direction to determine the first corresponding position u θr of the current position u θr1 in the first direction. Similarly, the current position u θr can also be projected onto the second direction to determine the second corresponding position u θr of the current position u θr2 in the second direction.

[0061] In step S520, based on the positional relationship between the above-mentioned corresponding position and the target spatial point in this target direction, interpolation can be performed on the spatial point wind speed of the target spatial point to obtain the target wind speed.

[0062] For example, as Figure 3 shown, according to the positional relationship between the first corresponding position u θr1 and the target spatial points (such as spatial points u21 and u22) in the first direction, for example, the distance between the first corresponding position u θr1 and the target spatial points u21 and u22, interpolation can be performed based on the spatial point wind speeds of the target spatial points u21 and u22 to obtain the target wind speed of the first corresponding position u θr1 . Similarly, according to the positional relationship between the second corresponding position u θr2 and the target spatial points (such as spatial points u12 and u22) in the second direction, for example, the distance between the second corresponding position u θr2 and the target spatial points u12 and u22, interpolation can be performed based on the spatial point wind speeds of the target spatial points u12 and u22 to obtain the target wind speed of the second corresponding position u θr2 .

[0063] As an example, when the angle θ between the direction between the spatial point u21 (i.e., the center of the cross-section) and the current position with respect to the vertical direction is greater than or equal to 45°, the wind speed v at the first corresponding position u θr1 and the wind speed v at the second corresponding position u θr1 can be expressed by the following equations (1) and (2) respectively: θr2 θr2

[0064]

[0065]

[0066] where v 12 represents the wind speed at the spatial point u12, v 22 represents the wind speed at the spatial point u22, v 21 represents the wind speed at the spatial point u21, M represents the distance between the spatial points u12 and u22, N represents the distance between the spatial points u22 and u21, and r represents the distance from the current position to the spatial point u21 (i.e., the center of the cross-section), that is, the distance in the direction from the impeller center to the blade tip of the blade. Here, the distance M can be equal to the distance N.

[0067] When the angle θ between the direction between the spatial point u21 (i.e., the center of the cross-section) and the current position with respect to the vertical direction is less than 45°, the wind speed v at the first corresponding position u θr1 and the wind speed v at the second corresponding position u θr1 can be expressed by the following equations (3) and (4) respectively: θr2 θr2

[0068]

[0069]

[0070] where v 12 represents the wind speed at the spatial point u12, v 11 represents the wind speed at the spatial point u11, v 21 represents the wind speed at the spatial point u21, M represents the distance between the spatial points u11 and u21, and N represents the distance between the spatial points u12 and u11.

[0071] In step S420, the target wind speeds in each target direction can be synthesized to determine the wind speed data at the current position.

[0072] ​​​​In this step, based on the angles between the current position and the target directions, the target wind speeds at the corresponding positions in the target directions can be synthesized according to geometric methods to determine the wind speed at the current position.

[0073] As an example, in step S420, the wind speed data at the current position can be determined in the following manner: based on the blade direction of the blade where the current position is located, which points from the impeller center to the blade tip, the target equivalent wind speeds in the target directions are synthesized to determine the equivalent wind speed data at the current position.

[0074] Taking Figure 3 as an example, for the first corresponding position u θr1 the target equivalent wind speed A in the direction of the current position (i.e., the above-mentioned blade direction) and the second corresponding position u θr2 the target equivalent wind speed B in the direction of the current position can be respectively expressed by the following equations (5) and (6):

[0075] A = v θr1 ·|sinθ| (5)

[0076] B = v θr2 ·|cosθ| (6)

[0077] Based on equations (5) and (6), the wind speed v θr at the current position is: v θr = A + B.

[0078] Although the above calculations were performed using the wind speeds of the four target space points in the upper right position, it is not limited to this. The wind speeds of other positions such as the lower left position, upper left position, and lower right position can also be used for calculations in a similar manner, and more or fewer target space points can be used in the calculations. Figure 2 For example, in the cross-section, only 5 space points of the measured wind speed can also be included. In this example, in one case, as

[0079] shown, still taking the wind speed to be calculated in the upper right region relative to the hub center as an example, the target equivalent wind speed A' of the first corresponding position u Figure 6 in the direction of the current position (i.e., the above-mentioned blade direction) and the target equivalent wind speed B' of the second corresponding position u θr1 in the direction of the current position can be respectively expressed by the following equations (7) and (8): θr2

[0080]

[0081]

[0082] ​Among them, v1 represents the wind speed at spatial point u1, v0 represents the wind speed at spatial point u0, v2 represents the wind speed at spatial point u2, M represents the distance between spatial point u1 and spatial point u0, and N represents the distance between spatial point u2 and spatial point u0.

[0083] Based on Equation (7) and Equation (8), the wind speed v at the current position θr is: v θr = A′ + B′.

[0084] In the example where there are 5 spatial points of the measured wind speed within the cross-section, in another case, as Figure 7 shown, still taking the calculated wind speed being in the upper right region relative to the hub center as an example, the first corresponding position u θr1 The target equivalent wind speed A″ in the direction of the current position (i.e., the above-mentioned blade direction) and the second corresponding position u θr2 The target equivalent wind speed B″ in the direction of the current position can be respectively expressed by the following Equations (9) to (12):

[0085]

[0086]

[0087]

[0088]

[0089] Among them, v1 represents the wind speed at spatial point u1, v0 represents the wind speed at spatial point u0, v2 represents the wind speed at spatial point u2, v4 represents the wind speed at spatial point u4, M represents the horizontal distance between spatial point u1 and spatial point u0, and N represents the vertical distance between spatial point u4 and spatial point u0.

[0090] Based on Equation (9) and Equation (10), the wind speed v at the current position θr is: v θr = A″ + B″.

[0091] Here, it should be noted that although the spatial position relationship and wind speed are calculated in the way of a three-dimensional coordinate system above, it is not limited to this. For example, it can also be converted into other coordinate systems such as a polar coordinate system for calculation.

[0092] Through the above method, the geometric operation can be combined with the wind speed estimation, and the wind speed at any position within the cross-section can be calculated, which is more conducive to analyzing the overall wind condition in front of the turbine impeller.

[0093] In step S120, based on the wind speed data at multiple positions, the equivalent wind speed data of each blade can be determined.

[0094] In this step, when determining the wind speeds at multiple positions on the blade, the equivalent wind speed of the entire blade can be equivalently obtained.

[0095] As an example, in this step S120, the equivalent wind speed data of each blade can be determined in the following manner: As Figure 8 shown, in step S810, the wind speed data at multiple positions on the blade can be accumulated along the blade length in the blade direction from the impeller center to the blade tip to obtain the wind speed accumulation; in step S820, the equivalent wind speed data of the blade can be determined based on the wind speed accumulation and the blade length.

[0096] Specifically, the equivalent wind speed over the entire blade length can be obtained by accumulating the wind speed data at each position on the blade.

[0097] For example, the impeller azimuth angle γ and rotational speed Ω of the wind turbine generator set at any time T can be obtained. At a subsequent time T + t, the impeller azimuth angle can be γ′ = γ + Ωt. Assuming that the spatial position information of the three blades at any time T + t can be predicted or measured as γ1, γ2, and γ3, then γ1 = γ′, and In this example, at any time T + t, further, the equivalent wind speeds passing through the three blades can be calculated respectively based on the following equations (13), (14), and (15):

[0098]

[0099]

[0100]

[0101] where u1′, u2′, and u3′ respectively represent the equivalent wind speeds of the three blades, u r1ri , u r2ri and u r3ri respectively represent the wind speeds at the i-th position on the three blades, n is the number of the above-mentioned multiple positions (i.e., target positions) on each blade, and respectively represent the wind speed accumulations (which can also be referred to as relative wind energy accumulations) of the three blades.

[0102] r i represents the distance of the i-th position from the impeller center in the blade direction from the impeller center to the blade tip, R is the impeller radius, dr irepresents the distance between the i-th position and the (i - 1)-th position in the above-mentioned blade direction, where dr1 represents the distance between the 1st position and the blade root in the above-mentioned blade direction. Figure 9 shows the distances of each position in the example where n = 2.

[0103] f(r i ) represents a function with r i as the independent variable, which can be obtained according to the slope of the load change of each cross-section of the blade near the rated wind speed; alternatively, it can also be a function with the pitch angle and r i as the independent variables, which can be obtained according to the slope of the load change of each cross-section of the blade at different pitch angles. As an example, here, f(r) = 1 can be taken.

[0104] By the above method, the equivalent wind speed of each blade at any moment can be obtained by accumulating the wind speeds at multiple positions. Since different blades are at different impeller orientations at different times, the wind speed conditions at different orientations of the impeller can be characterized, which is beneficial to subsequent determination of wind speed differences.

[0105] In addition, when determining the equivalent wind speed of the blade by accumulating the wind speeds at multiple positions on the blade, in fact, the wind speeds at multiple positions from the impeller center position to the blade tip position are all taken into account, so that the equivalent wind speed can characterize the wind speed condition at the orientation where the blade is located, rather than the wind speed at a certain point.

[0106] It should be noted that although the above description is given by taking a three-blade unit as an example, it is not limited thereto, and the above method can also be applied to the case of more or fewer blades.

[0107] In step S130, based on the equivalent wind speed data of each blade, the wind speed difference between different orientations of the impeller surface can be determined.

[0108] In this step, the wind speed at this orientation of the impeller surface can be determined according to the blade azimuth angle corresponding to the equivalent wind speed of the blade, so that the wind speed difference between different orientations of the impeller surface can be determined according to the equivalent wind speeds of different blades.

[0109] As an example, the wind speed difference between different orientations of the impeller surface can be determined in the following way: determining the first deviation between the equivalent wind speed data of every two blades and taking the first deviation as the wind speed difference; and / or determining the second deviation between the time series data in the equivalent wind speed data of each blade and taking the second deviation as the wind speed difference.

[0110] Specifically, in one example, the difference between the equivalent wind speeds of every two blades at any given moment can be used as the above-mentioned wind speed difference. Since different blades are at different azimuths at this moment, the wind speed differences in different azimuths within the impeller plane can be determined in this way.

[0111] Optionally or additionally, in another example, an equivalent wind speed analysis can be performed for the same blade in terms of time series. This is because the azimuth angle of the blade will continuously change during the rotation of the impeller. Therefore, the equivalent wind speed of a single blade calculated in terms of time series can represent the equivalent wind speeds of the blade at different azimuth angles. These equivalent wind speeds can be regarded as the equivalent wind speeds in different azimuths within the impeller plane to determine the wind speed differences in different azimuths.

[0112] The above-mentioned wind speed differences in different azimuths can be the wind speed differences between any two azimuths. In this way, it is possible to calculate whether there are any deviations in the wind speeds in all directions within the impeller plane that may cause an increase in load. Compared with the related art method of only calculating the upper and lower sides in the vertical direction or the left and right sides in the horizontal direction, it is possible to comprehensively grasp the wind speed situation and make a more accurate judgment of abnormal wind conditions. For example, even when facing uneven wind conditions such as a wind speed magnitude distribution in the shape of ">" or "<", it is possible to sense the wind speeds at the two azimuths of ">" or "<" to judge the difference between the wind speeds at these two azimuths.

[0113] In addition, according to an embodiment of the present disclosure, when calculating the wind speed difference, the equivalent wind speed data of the blades can be screened to select the data in the frequency band where the rotational frequency of the impeller is located for difference calculation.

[0114] Specifically, the pitch control method may further include: based on the rotational frequency of the impeller of the wind turbine generator, screening the data in the frequency band where the rotational frequency is located in the equivalent wind speed data of each blade to obtain the screened data; based on the screened data, determining the wind speed difference.

[0115] Here, the rotational frequency of the impeller corresponds to the impeller speed. Therefore, it can also be understood as screening the equivalent wind speed data in the frequency band where the impeller speed is located to determine the wind speed difference based on the screened data.

[0116] As an example, the process of screening data can be performed by a filter. In this way, using the data in the frequency band where the rotational frequency is located for wind speed difference calculation can make the calculation result more accurate and better reflect the real wind condition. In addition, in this example, low-pass filtering or high-pass filtering of the filter can also be used to filter out clutter to eliminate sudden change data in the waveform, etc.

[0117] In step S140, the pitch control of the wind turbine generator can be performed according to the wind speed difference.

[0118] In this step, given the wind speed differences between different orientations within the known impeller surface, it is possible to determine whether pitch control is required based on the magnitude of the wind speed differences.

[0119] As an example, when the wind speed differences are characterized by the above-mentioned first deviation and / or second deviation, pitch control of the wind turbine can be performed in the following manner: in response to the first deviation satisfying a preset first deviation condition and / or the second deviation satisfying a preset second deviation condition, determine the independent pitch angle of each blade; based on the independent pitch angle, perform pitch control on the wind turbine.

[0120] Here, the first deviation condition can represent the condition that the first deviation exceeds the wind speed deviation that the unit can withstand. When the first deviation satisfies the first deviation condition, pitch control can be performed on the unit to reduce the operating load; similarly, the second deviation condition can represent the condition that the second deviation exceeds the wind speed deviation that the unit can withstand. When the second deviation satisfies the second deviation condition, pitch control can be performed on the unit to reduce the operating load.

[0121] As an example, the first deviation condition can be that the first deviation is greater than a preset first trigger threshold, and the second deviation condition can be that the second deviation is greater than a preset second trigger threshold. Here, the first trigger threshold and the second trigger threshold can be set according to actual needs.

[0122] In this step, load reduction can be achieved through independent pitch control. For example, the independent pitch angle for independent pitch control (Individual pitch control, IPC) of each blade can be calculated, and the independent pitch angle can also be superimposed on the collective pitch angle of collective pitch control (CPC) to obtain the final pitch reference angle for pitch control.

[0123] The following will describe an example process of pitch control by characterizing the wind speed differences through the first deviation and the second deviation respectively.

[0124] In one example, as Figure 10 shown, the equivalent wind speed data of each blade in time series (for example, the equivalent wind speed u1' of blade No. 1, the equivalent wind speed u2' of blade No. 2, and the equivalent wind speed u3' of blade No. 3 within a predetermined time period) can be input into a filter to screen out the data in the frequency band where the rotational frequency of the impeller is located through the filter.

[0125] Based on the filtered data, the equivalent wind speed data of every two blades can be subtracted to obtain three difference values (i.e., the above-mentioned first deviation), and the maximum deviation value is selected from these three deviation values as the wind speed difference for determining whether pitch control is required.

[0126] As Figure 10 shown, the maximum deviation value can be compared with the first trigger threshold. In response to the maximum difference value being greater than the first trigger threshold, open-loop control can be performed through a Proportion-Integral-Differential (PID) controller, and the independent pitch angle for independent pitch control can be calculated based on the maximum deviation value, such as the independent pitch angles under the direct axis and the quadrature axis.

[0127] In another example, as Figure 11 shown, the equivalent wind speed data of each blade in time series (e.g., the equivalent wind speed u1' of blade 1, the equivalent wind speed u2' of blade 2, and the equivalent wind speed u3' of blade 3 within a predetermined time period) can be input into a filter to filter out the data in the frequency band where the rotational frequency of the impeller is located through the filter.

[0128] Based on the filtered data, the standard deviation (STD) of each blade in time series (i.e., the above-mentioned second deviation) can be calculated, and the maximum deviation value is selected from these three deviation values as the wind speed difference for determining whether pitch control is required.

[0129] As Figure 11 shown, the maximum deviation value can be compared with the second trigger threshold. In response to the maximum deviation value being greater than the second trigger threshold, open-loop control can be performed through a Proportion-Integral-Differential (PID) controller, and the independent pitch angle for independent pitch control can be calculated based on the maximum deviation value, such as the independent pitch angles under the direct axis and the quadrature axis.

[0130] Through the above two methods of calculating wind speed difference and pitch control methods, the wind speed differences in different orientations within the impeller plane can be determined, which can be selected or used in combination according to the actual situation, or the two methods can also be used to verify each other to improve the accuracy of wind speed difference calculation, which is beneficial to more accurately sense the wind condition to determine whether pitch control is required and protect the safety of the unit.

[0131] In addition, in step S140, for example, through an inverse D / Q transformation, an inverse operation can be performed based on the independent pitch angles determined above under the direct axis and the quadrature axis to obtain the independent pitch angles of each blade. For example, for a three-blade wind turbine, the independent pitch angles of the three blades can be represented as β1, β2, and β3, which can be obtained through the following formula (16):

[0132]

[0133] wherein, represents the current azimuth of the impeller, θ d and θ q respectively represent the independent pitch angles under the direct axis and the quadrature axis.

[0134] For a two-blade wind turbine, the independent pitch angles of the two blades can be represented as β1 and β2, which can be obtained through the following formula (17):

[0135]

[0136] wherein, represents the current azimuth of the impeller, θ d and θ q respectively represent the independent pitch angles under the direct axis and the quadrature axis.

[0137] According to the pitch control method of the wind turbine of the present disclosure described above, the wind turbine can be pitch-controlled by determining the wind speed difference between different azimuths in the impeller plane, reducing the load in a timely manner, reducing the load on the nose components of the wind turbine, and increasing the operating life of the wind turbine.

[0138] According to a second aspect of the embodiments of the present disclosure, a computer device is provided. Specifically, the pitch control method of the above-mentioned wind turbine can be executed by a computer device, and the computer device includes: at least one processor; at least one memory storing computer-executable instructions, wherein when the computer-executable instructions are run by the at least one processor, the at least one processor is caused to execute the pitch control method of the wind turbine according to the exemplary embodiments of the present disclosure.

[0139] As an example, the computer device can be a PC computer, a tablet device, a personal digital assistant, a smart phone, or other devices capable of executing the above instruction set. Here, the computer device does not have to be a single electronic device, and can also be any assembly of devices or circuits capable of executing the above instructions (or instruction sets) alone or jointly. The computer device can also be a part of an integrated control system or a system manager, or can be configured as a portable electronic device interconnected with a local or remote (e.g., via wireless transmission) interface.

[0140] In a computer device, 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, the processor may also include an analog processor, a digital processor, a microprocessor, a multi-core processor, a processor array, a network processor, and the like.

[0141] The processor may execute instructions or code stored in the memory, where the memory may also store data. The instructions and data may also be sent and received via a network interface device over a network, where the network interface device may employ any known transmission protocol.

[0142] The memory may be integrated with the processor, for example, by arranging RAM or flash memory within an integrated circuit microprocessor or the like. Additionally, the memory may include a separate device, such as an external disk drive, a storage array, or other storage devices usable by any database system. The memory and the processor may be operatively coupled or may communicate with each other, for example, via an I / O port, a network connection, etc., such that the processor can read files stored in the memory.

[0143] Furthermore, the computer device may also include a video display (such as a liquid crystal display) and a user interaction interface (such as a keyboard, a mouse, a touch input device, etc.). All components of the computer device may be connected to each other via a bus and / or a network.

[0144] According to a third aspect of an embodiment of the present disclosure, a wind turbine generator set is provided, which may include the computer device according to the embodiment of the present disclosure. For example, the computer device may be located in the pitch control system or the overall unit control system of the wind turbine generator set, or may be connected to the pitch control system or the overall unit control system of the wind turbine generator set.

[0145] The pitch control method of a wind turbine according to an embodiment of the present disclosure can be written as a computer program and stored on a computer-readable storage medium. When the instructions in the computer-readable storage medium are run by at least one processor, it causes the at least one processor to execute the pitch control method of the wind turbine according to the exemplary embodiments of the present disclosure. 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 memory, hard disk drive (HDD), solid state drive (SSD), card memory (such as, multimedia card, secure digital (SD) card or extreme digital (XD) card), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid state disk, and any other device that is configured to store a computer program and any associated data, data files, and data structures in a non-transitory manner and provide the computer program and any associated data, data files, and data structures to a processor or computer such 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 by one or more processors or computers.

[0146] The specific embodiments of the present disclosure have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that these embodiments can be modified and varied without departing from the principles and spirit of the present disclosure as defined by the claims and their equivalents. These modifications and variations should also be within the scope of protection of the claims of the present disclosure.

Claims

1. A pitch control method for a wind turbine generator, characterized in that, The pitch control method includes: Based on the wind speed data on the oncoming flow side of the wind turbine generator set, determining the wind speed data at multiple positions on each blade of the wind turbine generator set; Based on the wind speed data at the multiple positions, determining the equivalent wind speed data of each blade; Based on the equivalent wind speed data of each blade, determining the wind speed difference between different azimuths on the impeller plane; According to the wind speed difference, performing pitch control on the wind turbine generator set.

2. The pitch control method according to claim 1, wherein The wind speed data on the oncoming flow side includes the spatial point wind speeds of multiple spatial points in the same plane on the oncoming flow side. Among them, for each position on each blade, the wind speed data of each position is determined by the following method: Based on the positional relationship between the multiple spatial points and the current position and the spatial point wind speeds of the multiple spatial points, determining the wind speed data of the current position.

3. The pitch control method according to claim 2, wherein The wind speed data of the current position is determined by the following method: Based on the spatial point wind speeds of the target spatial points in multiple target directions among the multiple spatial points and the positional relationship between the current position and the target spatial points, determining the target wind speeds of the current position in each target direction; Synthesizing the target wind speeds in each target direction to determine the wind speed data of the current position.

4. The pitch control method according to claim 3, wherein For each target direction, the target wind speed is determined by the following method: Based on the positional relationship between the current position and the target spatial point in this target direction, determining the corresponding position of the current position in this target direction; Based on the positional relationship between the corresponding position and the target spatial point in this target direction, interpolating the spatial point wind speed of the target spatial point to obtain the target wind speed.

5. The pitch control method according to claim 3, characterized in that The synthesizing the target wind speeds in each target direction to determine the wind speed data of the current position includes: Based on the blade direction from the impeller center to the blade tip of the blade where the current position is located, synthesizing the target equivalent wind speeds in each target direction to determine the equivalent wind speed data of the current position.

6. The pitch control method according to claim 1, wherein The equivalent wind speed data of each blade is determined by the following method: Accumulating the wind speed data of the multiple positions on the blade along the blade length in the blade direction from the impeller center to the blade tip of the blade to obtain a wind speed accumulation; Based on the wind speed accumulation and the blade length, determining the equivalent wind speed data of the blade.

7. The pitch control method according to claim 1, characterized in that The wind speed difference between different azimuths on the impeller plane is determined by the following method: Determining a first deviation between the equivalent wind speed data of every two blades, and taking the first deviation as the wind speed difference; and / or, Determining a second deviation between the time series data in the equivalent wind speed data of each blade, and taking the second deviation as the wind speed difference.

8. The pitch control method according to claim 7, wherein The wind turbine generator set is pitch-controlled by the following method: In response to the first deviation satisfying a preset first deviation condition and / or the second deviation satisfying a preset second deviation condition, determining the independent pitch angle of each blade; Based on the independent pitch angle, performing pitch control on the wind turbine generator set.

9. The pitch control method according to claim 1, wherein The pitch control method further includes: Based on the rotation frequency of the impeller of the wind turbine generator set, screening the data in the equivalent wind speed data of each blade that is located in the frequency band where the rotation frequency is located to obtain the screened data; Based on the filtered data, determine the wind speed difference.

10. A computer device, characterized in that, Comprising: At least one processor; At least one memory storing computer-executable instructions, wherein, when the computer-executable instructions are run by the at least one processor, the at least one processor is caused to execute the pitch control method of the wind turbine according to any one of claims 1-9.

11. A wind power generating set, characterized in that, The wind turbine includes the computer device according to claim 10.

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