Method for yaw control of a wind turbine and wind turbine

Abstract

The present disclosure provides a wind turbine group and a clearance protection method of the wind turbine group. The clearance protection method comprises: determining a first wind speed at a first position of an impeller of the wind turbine group and a second wind speed at a second position of the impeller based on measured wind speed data; determining a first cumulative amount of the first wind speed within a preset time period before reaching the impeller and determining a second cumulative amount of the second wind speed within the preset time period; determining a wind shear in a specific direction between the first position and the second position based on the first cumulative amount and the second cumulative amount; and performing clearance protection based on the wind shear. The clearance protection method of the wind turbine group and the wind turbine group according to the present disclosure solve the problem that the existing clearance protection scheme cannot effectively control the blade clearance in time due to hysteresis, and can take clearance protection in advance, so that the clearance protection control is more timely and effective.

Description

Technical Field

[0001] This disclosure relates to the field of wind power generation, and more specifically, to a method for airspace protection of a wind turbine generator set and a wind turbine generator set. Background Technology

[0002] As the rotor diameter and overall capacity of wind turbine generator sets increase, the overall cost becomes a significant constraint. The clearance issue of wind turbine generator sets has become one of the main constraints on blade design. In the manufacturing process of related wind turbine generator sets, clearance measurement modules are commonly used to measure the blade clearance value in real time for clearance protection.

[0003] However, in the scheme of real-time measurement of air clearance value for protection, the air clearance protection control usually only responds when the measured air clearance value is lower than a certain value. Its response speed may be slow and there is a certain lag. When the requirements for air clearance protection are high or the wind conditions faced by the unit are complex, it may not be able to control the blade air clearance in a timely and effective manner, and there is a risk of blade sweeping the tower. Summary of the Invention

[0004] Given that existing airspace protection schemes are lagging and cannot effectively control blade airspace in a timely manner, this disclosure provides an airspace protection method for wind turbine generator sets and a wind turbine generator set.

[0005] The first aspect of this disclosure provides a method for airspace protection of a wind turbine generator set, the method comprising: determining a first wind speed at a first position of the rotor of the wind turbine generator set and a second wind speed at a second position of the rotor based on measured wind speed data; determining a first cumulative amount of the first wind speed within a preset time period before reaching the rotor, and determining a second cumulative amount of the second wind speed within the preset time period; determining wind shear in a specific direction between the first position and the second position based on the first cumulative amount and the second cumulative amount; and performing airspace protection based on the wind shear.

[0006] Optionally, the first wind speed and the second wind speed 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 time 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 time; and determining the first wind speed and the second wind speed at the current time based on the composite wind speed on each path at the current time.

[0007] Optionally, for each path, the composite wind speed is determined as follows: based on the wind speed processing parameters on the impeller at the current moment and the distance of each of the plurality of points from the impeller, a target time corresponding to each point is determined, wherein the target time corresponding to each point represents the moment when the wind moving to the nearest measurement point is at that point at the current moment, and the nearest measurement point is the point among the plurality of points closest to the impeller; based on the wind speed data, the wind speed measurement data of each point at the corresponding target time is determined; based on the wind speed measurement data of each point at the corresponding target time and the direction of each path, the composite wind speed is determined.

[0008] Optionally, the wind speed processing parameters on the impeller at the current moment are determined based on the first wind speed and the second wind speed at the previous moment.

[0009] Optionally, the first cumulative amount and the second cumulative amount are determined by: determining the first cumulative amount based on the integral of the first wind speed over the preset time period; and determining the second cumulative amount based on the integral of the second wind speed over the preset time period.

[0010] Optionally, the first position is the upper side of the impeller, and the second position is the lower side of the impeller, wherein the preset time period is less than the most recent measurement time, and the most recent measurement time is the time obtained based on the most recent measurement distance from the impeller in the wind speed data and the wind speed processing parameters on the impeller at the current moment.

[0011] Optionally, airspace protection based on the wind shear includes: responding to different preset conditions met by the wind shear by adopting different pitch control strategies, wherein the pitch control strategy includes at least one of the following: controlling the wind turbine pitch based on unified pitch control; controlling the wind turbine pitch based on independent pitch control and unified pitch control; controlling the wind turbine pitch based on independent pitch control and unified pitch control, and limiting the power generation of the wind turbine; controlling the wind turbine to shut down.

[0012] Optionally, the step of adopting different pitch control strategies in response to different preset conditions of wind shear includes: controlling the wind turbine to pitch based on unified pitch control in response to the wind shear and a first threshold satisfying a first preset condition; controlling the wind turbine to pitch based on independent pitch control and unified pitch control in response to the wind shear being between the first threshold and a second threshold; controlling the wind turbine to pitch based on independent pitch control and unified pitch control in response to the wind shear being between the second threshold and a third threshold, and limiting the power generation of the wind turbine; and controlling the wind turbine to shut down in response to the wind shear and the third threshold satisfying a second preset condition, wherein the second threshold is between the first threshold and the third threshold.

[0013] Optionally, controlling the pitch of the wind turbine generator set based on independent pitch control and unified pitch control includes: in response to the blades of the wind turbine generator set being within a preset azimuth angle range, determining an additional pitch angle reference value for the blades based on independent pitch control; determining a unified pitch angle reference value for all blades based on unified pitch control; and controlling the pitch of the wind turbine generator set based on the additional pitch angle reference value and the unified pitch angle reference value.

[0014] 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 the computer-executable instructions, when executed by the at least one processor, cause the at least one processor to perform an airspace protection method for a wind turbine generator according to an exemplary embodiment of this disclosure.

[0015] A third aspect of this disclosure provides a wind turbine generator set, the wind turbine generator set including the computer equipment described in exemplary embodiments of this disclosure.

[0016] 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 an airspace protection method for a wind turbine generator according to an exemplary embodiment of this disclosure.

[0017] According to the wind turbine generator headroom protection method and wind turbine generator set disclosed herein, a first wind speed and a second wind speed at different positions on the rotor can be determined based on the measured wind speed data. Furthermore, a first cumulative amount and a second cumulative amount can be determined based on the first wind speed and the second wind speed over a period of time before reaching the rotor. Thus, wind shear can be determined based on the first cumulative amount and the second cumulative amount for headroom protection. In this way, the wind shear determined by the cumulative amount of wind speed over a period of time can reflect the wind change trend and energy accumulation, which is beneficial for predicting the risk of blade sweeping to the tower and taking headroom protection measures in advance, making headroom protection control more timely and effective. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart illustrating an airspace protection method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0019] Figure 2 This is a schematic flowchart illustrating the steps of determining a first wind speed and a second wind speed in a wind turbine generator headroom protection method according to an exemplary embodiment of the present disclosure.

[0020] Figure 3 This is a schematic diagram illustrating the acquisition of wind speed data in an airspace protection method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0021] Figure 4 This is a schematic flowchart illustrating the steps of determining the composite wind speed in a wind turbine generator headroom protection method according to an exemplary embodiment of the present disclosure.

[0022] Figure 5 This is a schematic diagram illustrating the changes in the first and second wind speeds in an airspace protection method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0023] Figure 6 and Figure 7 This is a schematic diagram illustrating a first and second cumulative amount in an airspace protection method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0024] Figure 8 This is a schematic flowchart illustrating the steps of controlling the pitch of a wind turbine generator set in an airspace protection method according to an exemplary embodiment of the present disclosure.

[0025] Figure 9 This is a schematic diagram illustrating the wind turbine pitch azimuth angle and airspace protection in an airspace protection method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0026] Figure 10This is a schematic diagram illustrating the blade clearance timing before and after independent pitch control is performed using a wind turbine generator clearance protection method according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0027] 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.

[0028] 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.

[0029] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In view of the foregoing problems, exemplary embodiments of this disclosure provide a method for protecting the airspace of a wind turbine generator set, a wind turbine generator set, a computer device, and a computer-readable storage medium to solve or at least mitigate the problems existing in the related art.

[0036] According to a first aspect of an exemplary embodiment of the present disclosure, a method for airspace protection of a wind turbine generator set is provided. The airspace protection method may include the following steps:

[0037] like Figure 1 As shown, in step S110, the first wind speed at the first position of the wind turbine rotor and the second wind speed at the second position of the rotor can be determined based on the measured wind speed data.

[0038] In this step, wind speed data can be obtained by wind measuring devices such as laser ranging radar, video camera and millimeter-wave ranging radar. However, the embodiments of this disclosure are not limited to this and can also be obtained by other devices or methods.

[0039] The first position and the second position can be different positions on the impeller. For example, the first position can be the upper side of the impeller and the second position can be the lower side of the impeller. However, it is not limited to this. For example, the first position can also be the upper right side of the impeller and the second position can be the lower left side of the impeller.

[0040] As an example, the first and second wind speeds can be obtained by reconstructing wind speed data. For instance, the first and second wind speeds can be determined in the following ways:

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] In one example, the wind speed processing parameters can be obtained by measuring with an anemometer installed at or near the impeller; in another example, the wind speed processing parameters at the impeller at the current moment can be determined based on the first wind speed and the second wind speed at the previous moment, for example, the average wind speed of the first and second wind speeds at the previous moment. In the example of determining the wind speed processing parameters based on the first and second wind speeds, a temporal correlation between wind speeds can be established, making the obtained wind speed processing parameters more consistent with the actual wind speed variation trend and better reflect the wind speed characteristics at the impeller.

[0050] 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.

[0051] As an example, for each path, the composite wind speed can be determined in the following way:

[0052] 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.

[0053] 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.

[0054] 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.

[0055] For example, with Figure 3 For example, based on the distance x from point P12 to the impellerj 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.

[0056] 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.

[0057] 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 the RWS. ij (t-Δt ij ).

[0058] 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.

[0059] 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.

[0060] For example, the composite wind speed U of the i-th path at the current time can be represented by the following equation (1). Beami (t):

[0061]

[0062] 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, such as the average wind speed; RWS 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.

[0063] 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 clearance protection control more effective.

[0064] 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.

[0065] In step S230, the first wind speed and the second wind speed at the current time can be determined based on the composite wind speed on each path at the current time.

[0066] In this step, the composite wind speeds of each path can be used to determine the first wind speed and the second wind speed. Specifically, as mentioned above, each composite wind speed reflects 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 wind speed at the first location and the second wind speed at the second location.

[0067] In the example where the first position is the upper side of the impeller and the second position is the lower side of the impeller, with 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 wind speed equivalent to the wind speed on the upper side of the impeller and a second wind speed equivalent to the wind speed on the lower side of the impeller.

[0068] Specifically, the first wind speed U1 and the second wind speed U2 can be represented by the following equations (2) and (3):

[0069]

[0070]

[0071] In this way, the first and second wind speeds at the desired location can be reconstructed based on the wind speed data. The first and second wind speeds obtained by the above 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 airspace control effect.

[0072] 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.

[0073] Furthermore, although the method of obtaining the first wind speed and the second wind speed through wind speed reconstruction is described above, the method of determining the first wind speed and the second wind speed is not limited to this. For example, the wind speed data may include wind speed data near the first position and near the second position, so that the first wind speed and the second wind speed can be obtained by using the wind speed data near the first position and near the second position through methods such as difference and fitting.

[0074] In step S120, the first cumulative amount of the first wind speed within a preset time period before reaching the impeller can be determined, and the second cumulative amount of the second wind speed within the preset time period can be determined.

[0075] In this step, since the wind measurement equipment measures the wind speed in front of the rotor, the cumulative wind speed over a preset time period before reaching the rotor is used to determine the wind conditions. This ensures that wind conditions with a risk of blade swirl attack can be identified in advance and the unit can be controlled in a timely manner. Here, blade swirl attack refers to a blade impacting the tower during the operation of a wind turbine, which may occur in extreme weather.

[0076] The first and second wind speeds can, for example, be variable. Figure 5 The trends of the first and second wind speeds over time are shown, such as... Figure 5 As shown, the first wind speed can gradually decrease over time until time t0, and then gradually increase over time; the second wind speed can gradually increase over time until time t0, and then gradually decrease over time. At time t0, the first wind speed is at its minimum value in the entire curve, and the second wind speed is at its maximum value in the entire curve. Here, Figure 5 The purpose is to show the trend of wind speed changes, so no specific value is given.

[0077] As an example, the cumulative amount can be the accumulation of wind speed over time. For instance, the first cumulative amount can be determined based on the integral of the first wind speed over a preset time period, and the second cumulative amount can be determined based on the integral of the second wind speed over a preset time period.

[0078] by Figure 5 Taking the velocity curve as an example, the area enveloping the velocity curve can be used as the cumulative amount of wind speed, such as... Figure 6 and Figure 7 As shown, the first cumulative amount is the first envelope area s1 of the first wind speed curve U1(t) within a preset time period, and the second cumulative amount is the second envelope area s2 of the second wind speed curve U2(t) within a preset time period. The first envelope area s1 and the second envelope area s2 can be expressed by the following equations (4) and (5):

[0079]

[0080]

[0081] Among them, t now Δt represents the current time, and t represents the preset time interval. now -Δt represents the time period before the current time.

[0082] Here, as an example, the preset time period can be any length of time. For example, the preset time period can be shorter than the most recent measurement time, which can be the time obtained based on the most recent measurement distance from the impeller in the wind speed data and the wind speed processing parameters on the impeller at the current moment, such as, but not limited to, the time obtained by dividing the most recent measurement distance by the wind speed processing parameters at the current moment.

[0083] For example, the preset time period Δt can satisfy the following expression (6):

[0084]

[0085] Where x1 is the closest measured distance from the impeller in the wind speed data. This is a parameter for processing the wind speed on the impeller at the current moment; for example, it can be the average wind speed.

[0086] Furthermore, by ensuring that the preset time period is less than the time required for the wind speed to move from the nearest measured distance to the impeller at the current wind speed processing parameters, it is possible to further ensure the early identification of risky wind conditions.

[0087] Furthermore, as an example, the first and second wind speeds can be filtered before determining the first and second cumulative values. For instance, a first-order low-pass filter can be applied to the first and second wind speeds to obtain filtered wind speed values. Filtering the wind speeds can improve control stability. However, the filtering method is not limited to the above example, and other filtering methods can also be used; this disclosure does not impose any particular limitations on this.

[0088] In step S130, the wind shear in a specific direction between the first position and the second position can be determined based on the first cumulative amount and the second cumulative amount.

[0089] In this step, the specific direction can be, for example, the vertical direction; however, it is not limited to this and can also be other directions, such as those at an angle to the vertical direction.

[0090] 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. For example, vertical wind shear can refer to the change of the wind vector over vertical distances in the air, and it can include positive and negative shear. Negative vertical shear can be manifested as a lower-distance wind speed value being greater than a higher-distance wind speed value, while positive vertical shear can be manifested as a higher-distance wind speed value being greater than a lower-distance wind speed value.

[0091] In this step, the wind shear can be determined, for example, based on the difference between the first cumulative amount and the second cumulative amount, such as the difference between the first cumulative amount and the second cumulative amount or the difference between the second cumulative amount and the first cumulative amount.

[0092] For example, in the example where the first position is the upper side of the impeller and the second position is the lower side of the impeller, taking the above equations (4) and (5) as examples, for an upwind wind turbine, the wind shear V shear_diff It can be expressed by the following equation (7):

[0093] V shear_diff =s1-s2(7)

[0094] In the example above, an upwind wind turbine refers to a turbine where the rotor is installed in front of the nacelle in the direction of the wind, and the wind will blow over the rotor first and then over the nacelle. The embodiments of this disclosure can also be applied to downwind wind turbines, where the rotor is installed behind the nacelle in the direction of the wind, and the wind will blow over the nacelle first and then over the rotor. Taking equations (4) and (5) above as examples, for a downwind wind turbine, the wind shear V... shear_diff It can be expressed by the following equation (8):

[0095] V shear_diff =s2-s1(8)

[0096] In the embodiments of this disclosure, considering that wind is formed due to uneven heating of the Earth's surface caused by solar radiation, resulting in uneven pressure distribution in the atmosphere and horizontal air movement, and because airflow is constantly changing, wind pulsations, diurnal variations, seasonal variations, and even interannual variations are very significant, fluctuating greatly and extremely unstable. Therefore, the wind shear identification based on the cumulative wind speed proposed in the embodiments of this disclosure, by statistically analyzing wind speed changes over a preset time period, better reflects the trend of wind speed changes through the perspective of energy accumulation. The energy accumulation of wind is mapped onto the wind turbine generator, making its impact more intuitive and direct, thereby enabling more accurate judgment of wind shear conditions and timely and accurate airspace protection.

[0097] Furthermore, although the example of calculating wind shear based on the first and second cumulative amounts described above is not limited to this, it can also be calculated in other ways.

[0098] In step S140, air clearance protection can be performed based on wind shear.

[0099] In this step, for example, a pitch control strategy for the wind turbine can be determined based on wind shear to mitigate or offset the reduction in headroom caused by wind shear through pitch control.

[0100] Taking equation (7) above as an example, when a vertical negative shear wind condition occurs, the wind shear V shear_diffIt can be less than 0; taking the above formula (8) as an example, when a vertical positive shear wind condition occurs, the wind shear V shear_diff It can be greater than 0. A threshold can be set for wind shear to identify vertical negative shear conditions. In one example, the air clearance protection can be determined by comparing the wind shear and the threshold.

[0101] As an example, different preset conditions can be set for wind shear, and different pitch control strategies can be adopted by analyzing the current wind shear and the preset conditions.

[0102] Specifically, different pitch control strategies can be adopted in response to different preset conditions met by wind shear. The pitch control strategies include at least one of the following: controlling the pitch of the wind turbine generator based on unified pitch control; controlling the pitch of the wind turbine generator based on independent pitch control and unified pitch control; controlling the pitch of the wind turbine generator based on independent pitch control and unified pitch control, and limiting the power generation of the wind turbine generator; controlling the shutdown of the wind turbine generator.

[0103] Here, individual pitch control (IPC) can be pitch control for a single blade, where an independent pitch control reference value can be determined for each blade of the turbine. Collective pitch control (CPC) can be pitch control for all blades, where a uniform pitch angle can be determined for all blades.

[0104] In one example, it can be in response to wind shear and a first threshold V shear_diff Thres1 meets the first preset condition and controls the pitch of the wind turbine generator based on unified pitch control.

[0105] Here, the first preset condition could be, for example: when the wind shear is negative, the first threshold is negative, and the wind shear is greater than or equal to the first threshold V. shear_diff Thres1; When the wind shear is positive, the first threshold is positive, and the wind shear is less than or equal to the first threshold V. shear_diff Thres 1. In this case, it can be assumed that there is no risk of tower sweeping, and the unit can be operated according to its normal control mode.

[0106] In one example, this can be in response to wind shear being at a first threshold V. shear_diff Thres1 and the second threshold V shear_diff Between Thres2, the pitch of the wind turbine generator is controlled based on independent pitch control and unified pitch control.

[0107] Here, at the first threshold V shear_diff When Thres1 is negative, the second threshold Vshear_diff Thres2 can be less than the first threshold V. shear_diff Thres1; if the first threshold is positive, the second threshold V shear_diff Thres2 can be greater than the first threshold V. shear_diff Thres 1. In this situation, wind shear may bring the risk of blade sweeping to the tower, requiring the implementation of air clearance protection. Independent pitch control can be introduced on the basis of unified pitch control, so as to adjust the pitch angle of blades at different positions through independent pitch control, thereby balancing the risk of blade sweeping to the tower caused by wind shear.

[0108] In this way, independent pitch control can be introduced on the basis of unified pitch control, thereby adjusting the pitch angle of blades at different positions through independent pitch control, so as to balance the risk of blade sweeping caused by wind shear.

[0109] For example, such as Figure 8 As shown, the pitch of the wind turbine generator set can be controlled based on independent pitch control and unified pitch control in the following ways: Step S810: In response to the wind turbine generator set blades being within a preset azimuth angle range, an additional pitch angle reference value for the blades can be determined based on independent pitch control; Step S820: A unified pitch angle reference value for all blades can be determined based on unified pitch control; Step S830: The pitch of the wind turbine generator set can be controlled based on the additional pitch angle reference value and the unified pitch angle reference value.

[0110] Based on a unified pitch angle reference value, an additional pitch angle reference value can be calculated for each blade. Thus, for each blade, the unified pitch angle reference value and the additional pitch angle reference value can be superimposed, and the blade pitch can be controlled based on the superimposed reference value.

[0111] Here, the impeller azimuth angle can be the absolute position of the impeller along the direction of rotation. The impeller azimuth angle can have a zero point and vary from 0 to 360 degrees during rotation. The impeller azimuth angle can be directly measured, or the impeller rotational speed can be measured and the impeller azimuth angle calculated based on the impeller rotational speed.

[0112] The preset azimuth range can include the position where the blades are pointing vertically downwards. For example, when the zero point position is where the blades are pointing vertically upwards, the preset azimuth range can be 180° ± 30°. Within this range, independent pitch control can be performed; for example, when the blades are within the 180° ± 30° range, the blades can be controlled to retract. For example, as... Figure 9As shown, the blade can be retracted when it is at a 150° azimuth angle, so that the retracted blade action is maintained when the blade rotates to a 180° azimuth angle. This reduces the wind thrust experienced by the blade when it passes in front of the tower and increases the clearance between the blade and the tower.

[0113] Using the above method, periodic independent pitch control can be performed directly based on the impeller azimuth information, and pitch retraction can be executed near a preset azimuth angle (e.g., 180°), achieving air clearance protection while minimizing power generation loss. Furthermore, the above reference... Figure 8 The independent pitch control described is just an example. In this example, a control strategy of uniformly retracting the three blades can also be used to achieve air clearance protection without having to determine the azimuth angle of the impeller.

[0114] It should be noted that independent pitch control and unified pitch control can be implemented in any way. Figure 8 The steps shown are intended to illustrate how independent pitch control and unified pitch control can be combined to achieve airspace protection without or with minimal loss of power generation.

[0115] Furthermore, according to exemplary embodiments of this disclosure, since wind measuring devices such as lidar obtain wind speed information by measuring aerosol particles in the atmosphere, there may be invalid wind measuring data in environments with very few aerosols (e.g., extremely clean air) or very many aerosols (e.g., in foggy, rainy, or snowy weather), which will affect the accuracy of wind shearing conditions identification. Therefore, in response to the failure of the wind measuring device hardware, the pitch control unit of the wind turbine can be controlled based on independent pitch control and unified pitch control, thereby protecting the airspace safety of the unit to a certain extent.

[0116] In one example, this can be in response to wind shear being at a second threshold V. shear_diff Thres2 and the third threshold V shear_diff Between Thres3, based on independent pitch control and unified pitch control, the pitch of the wind turbine generator is controlled, and the power generation of the wind turbine generator is limited.

[0117] Here, at the second threshold V shear_diff When Thres2 is negative, the third threshold V shear_diff Thres3 can be less than the second threshold V. shear_diff Thres2; at the second threshold V shear_diff When Thres2 is positive, the third threshold V shear_ diff Thres3 can be greater than the second threshold V. shear_diffThres 2. In this situation, the wind conditions may be severe, and the risk of wind shearing causing blade sweeping is relatively high. In addition to implementing airspace protection, the power of the unit can also be limited to further ensure airspace safety while implementing independent pitch control.

[0118] In one example, it can be in response to wind shear and a third threshold V shear_diff Thres3 satisfies the second preset condition, controlling the wind turbine generator to shut down. Here, the second threshold V shear_diff Thres2 can be at the first threshold V shear_diff Thres1 and the third threshold V shear_diff Between Thres3.

[0119] Here, the second preset condition could be, for example, that when the wind shear is negative, the third threshold is negative, and the wind shear is greater than or equal to the third threshold V. shear_diff Thres3; When the wind shear is positive, the third threshold is positive, and the wind shear is less than or equal to the third threshold V. shear_diff Thres 3. In this situation, due to potentially extremely severe wind conditions, the shutdown protection should be triggered immediately.

[0120] In the above example, the first threshold, the second threshold, and the third threshold can be set according to actual needs. For example, suitable thresholds can be determined through field tests or design simulations. As long as the three satisfy the above relationship, different levels of thresholds can be set to achieve gradient protection of the airspace.

[0121] Based on the above example, an incremental protection scheme can be used for airspace protection, which can achieve airspace protection for wind turbine generators while ensuring the power generation of the wind turbine generators.

[0122] According to the wind turbine generator clearance protection method disclosed herein, the first wind speed and the second wind speed at different positions of the rotor can be determined based on the measured wind speed data. The first cumulative wind speed and the second cumulative wind speed can also be determined over a period of time before reaching the rotor, thereby determining the wind shear for clearance protection. Thus, the wind shear determined based on the cumulative wind speed over a period of time can reflect the wind change trend and energy accumulation, which is beneficial for predicting the risk of blade sweeping the tower and taking clearance protection measures in advance, making clearance protection control more timely and effective.

[0123] The following will refer to Figure 10 An example of performing independent pitch control using an airspace protection method for a wind turbine generator set according to an exemplary embodiment of the present disclosure is described.

[0124] Taking the extreme negative shear wind condition under the extreme wind shear (EWS) specified in the IEC-61400-1 standard as an example, the temporal variation trend of blade clearance is as follows, with and without independent pitch control of the clearance: Figure 10 The curve in the figure is shown.

[0125] Depend on Figure 10 The trend shows that when independent pitch control is used to maintain headroom, the blade headroom remains essentially constant even under extreme wind conditions; however, when independent pitch control is not used, the blade headroom will decrease. Here, Figure 10 The intention is to show the trend of changes in net clearance, therefore the specific net clearance and time values ​​are omitted.

[0126] According to the exemplary embodiments of this disclosure, the air clearance protection method can obtain the composite wind speed at different positions of the impeller through wind speed reconstruction, thereby analyzing the risk of blade sweeping to the tower. For example, when the entire unit operates under negative shear wind conditions (the wind speed on the underside of the impeller is higher than the wind speed on the topside of the impeller), the blade air clearance will be low, resulting in the risk of blade sweeping to the tower. In response, the exemplary embodiments of this disclosure can actively control the air clearance based on the first and second wind speeds obtained through reconstruction, according to the actual wind shear, to achieve blade air clearance protection.

[0127] Furthermore, the airspace protection method according to the exemplary embodiments of this disclosure can identify wind conditions based on wind measurements taken by wind measuring equipment, and can also combine impeller azimuth information to perform active control based on actual wind shear, such as independent pitch control, especially in vertical negative shear wind conditions, to perform whole-machine airspace protection and reduce the risk of blade sweeping the tower.

[0128] 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 airspace protection method for a wind turbine generator set according to an exemplary embodiment of this disclosure.

[0129] 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).

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] According to a third aspect of this disclosure, a wind turbine generator set is provided, which may include the computer equipment described in the exemplary embodiments of this disclosure.

[0135] For example, the computer device can be installed in the control system of a wind turbine generator set to control the pitch of the generator set.

[0136] 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 an airspace protection method for a wind turbine generator set according to an exemplary embodiment of this disclosure.

[0137] The airspace protection method for wind turbine generators 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.

[0138] 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 method of clearance protection for a wind turbine generator system, characterized by, The clearance protection method comprises: determining a first wind speed at a first position of an impeller of a wind turbine generator set and a second wind speed at a second position of the impeller based on measured wind speed data; determining a first cumulative amount of the first wind speed within a preset time period before reaching the impeller and determining a second cumulative amount of the second wind speed within the preset time period; determining a wind shear in a specific direction between the first position and the second position based on the first cumulative amount and the second cumulative amount; performing clearance protection based on the wind shear.

2. The headroom protection method of claim 1, wherein, The first wind speed and the second wind speed are determined in the following manner: obtaining wind speed data at a plurality of points on a plurality of paths pointing to the impeller from a wind direction based on a wind measuring device; determining a composite wind speed at a current time on each path according to the wind speed data, a pointing direction of each path, a distance of each point in the plurality of points from the impeller, and a wind speed processing parameter on the impeller at the current time; determining the first wind speed and the second wind speed at the current time based on the composite wind speed on each path at the current time.

3. The headroom protection method of claim 2, wherein, For each path, the composite wind speed is determined in the following manner: determining a target time corresponding to each point based on the wind speed processing parameter on the impeller at the current time and the distance of each point in the plurality of points from the impeller, wherein the target time corresponding to each point represents a time at which wind moving to the nearest measuring point at the current time is at the point, the nearest measuring point being the point in the plurality of points closest to the impeller; determining measurement data of a wind speed of each point at the corresponding target time according to the wind speed data; determining the composite wind speed based on the measurement data of the wind speed of each point at the corresponding target time and the pointing direction of each path.

4. The headroom protection method according to claim 2 or 3, characterized in that, The wind speed processing parameter on the impeller at the current time is determined based on the first wind speed at a previous time and the second wind speed at the previous time.

5. The headroom protection method of claim 1, wherein, The first cumulative amount and the second cumulative amount are determined in the following manner: determining the first cumulative amount based on an integral of the first wind speed within the preset time period; determining the second cumulative amount based on an integral of the second wind speed within the preset time period.

6. The headroom protection method of claim 1, wherein, The first position is an upper side of the impeller and the second position is a lower side of the impeller, wherein the preset time period is less than a nearest measuring time, the nearest measuring time being a time obtained based on a nearest measuring distance from the impeller in the wind speed data and the wind speed processing parameter on the impeller at the current time.

7. The headroom protection method of claim 1, wherein, Performing clearance protection based on the wind shear comprises: in response to the wind shear satisfying different preset conditions, adopting different pitch control strategies, wherein the pitch control strategies comprise at least one of the following: controlling the wind turbine generator set to pitch based on unified pitch control; controlling the wind turbine generator set to pitch based on independent pitch control and unified pitch control; controlling the wind turbine generator set to pitch based on independent pitch control and unified pitch control, and limiting power generation of the wind turbine generator set; controlling the wind turbine generator set to shut down.

8. The headroom protection method of claim 7, wherein, The different pitch control strategies include: In response to the wind shear satisfying a first preset condition with a first threshold value, controlling the wind turbine generator set to pitch based on unified pitch control; In response to the wind shear being between the first threshold value and a second threshold value, controlling the wind turbine generator set to pitch based on independent pitch control and unified pitch control; In response to the wind shear being between the second threshold value and a third threshold value, controlling the wind turbine generator set to pitch based on independent pitch control and unified pitch control, and limiting power generation of the wind turbine generator set; In response to the wind shear satisfying a second preset condition with the third threshold value, controlling the wind turbine generator set to shut down, wherein the second threshold value is between the first threshold value and the third threshold value.

9. The headroom protection method according to claim 7 or 8, characterized in that, The controlling the wind turbine generator set to pitch based on independent pitch control and unified pitch control includes: In response to a blade of the wind turbine generator set being within a preset azimuth angle range, determining an additional pitch angle reference value of the blade based on independent pitch control; Determining a unified pitch angle reference value of all blades based on unified pitch control; Controlling the wind turbine generator set to pitch based on the additional pitch angle reference value and the unified pitch angle reference value.

10. A computer device, comprising: comprise: 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 wind turbine generator set clearance protection method of any one of claims 1-9.

11. A wind power unit, characterized in that The wind turbine generator set comprises the computer device of claim 10.

12. A computer-readable storage medium, characterized in that, The computer readable storage medium, when executed by the at least one processor, causes the at least one processor to perform the wind turbine generator set clearance protection method of any one of claims 1-9.

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