Pitch change control method for wind turbine, and wind turbine

Abstract

A pitch change control method for a wind turbine, and a wind turbine. The pitch change control method comprises: on the basis of power data of a wind turbine, determining a corresponding blade roughness coefficient; on the basis of a preset pitch angle condition, determining a wind speed-pitch angle relation under the blade roughness coefficient; on the basis of the wind speed-pitch angle relation and wind speed data, determining a blade stall condition; and, in response to the wind turbine being in a blade stall state and according to the wind speed data and a preset pitch change control relation, controlling the wind turbine to change pitch. The control method can determine blade stall and perform a corresponding pitch change action while taking into account wind turbine power, so as to achieve a stall protection effect and improve the stability and reliability of the wind turbine.

Description

Pitch control method for wind turbine generator set and wind turbine generator set

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application No. 202311433184.6 filed on October 31, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] 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

[0004] As wind turbines become larger, their impellers and blades become longer. To balance overall cost and performance, the blades' stall margin is decreasing. Large impellers frequently stall in low-density, high-pollution environments. Once the blades stall, power cannot be increased, significantly reducing the unit's power generation.

[0005] In related technologies, when facing the problem of blade stall, the pitch angle is generally adjusted by power to prevent the unit from entering stall. However, after the unit enters stall, especially for large-impeller units, the power is stabilized in the low power range, and the power-based pitch change method cannot be implemented, so it cannot play a stall protection effect.

[0006] Summary of the Invention

[0007] In view of the problem in the related art that a power-based pitch control method cannot be implemented after the unit enters a stall, resulting in a failure to provide stall protection, the present disclosure provides a pitch control method for a wind turbine generator set and a wind turbine generator set.

[0008] A first aspect of the present disclosure provides a pitch control method for a wind turbine generator set, the pitch control method comprising: determining a blade roughness coefficient corresponding to current wind speed data based on current power data of the wind turbine generator set; determining a wind speed-pitch angle relationship under the blade roughness coefficient based on a preset pitch angle condition; determining a blade stall condition for the current wind speed data based on the wind speed-pitch angle relationship and the current wind speed data; in response to an indication that the wind turbine generator set is in a blade stall state due to a relationship between the current pitch angle of the wind turbine generator set and the blade stall condition, controlling the pitch of the wind turbine generator set according to the current wind speed data and a preset pitch control relationship.

[0009] A second aspect of the present 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, prompt the at least one processor to execute the pitch control method for a wind turbine generator set according to an embodiment of the present disclosure.

[0010] A third aspect of the present disclosure provides a wind turbine generator set, comprising the computer device according to the embodiment of the present disclosure.

[0011] A fourth aspect of the present disclosure provides a computer-readable storage medium, which, when instructions in the computer-readable storage medium are executed by at least one processor, prompts the at least one processor to execute the pitch control method of a wind turbine generator set according to an embodiment of the present disclosure.

[0012] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate some embodiments consistent with the present disclosure, and together with the description are used to explain the principles of the present disclosure, and do not constitute an improper limitation of the present disclosure.

[0014] FIG1 is a schematic flowchart illustrating a pitch control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0015] 2 and 3 are schematic flow charts illustrating steps of determining a blade roughness coefficient in a pitch control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0016] FIG4 is a schematic flow chart illustrating steps of determining a wind speed-pitch angle relationship in a pitch control method for a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0017] FIG5 is a schematic flow chart illustrating steps of controlling the pitch of a wind turbine generator set in a pitch control method of a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0018] FIG6 is a schematic flowchart illustrating a step of determining a preset pitch control relationship in a pitch control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0019] FIG7 is a schematic flowchart illustrating steps of obtaining filtered historical operating data in a pitch control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0020] FIG8 is a schematic flowchart illustrating determining a pitch angle control condition in a pitch control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0021] FIG9 is a flowchart illustrating an example of determining a preset pitch control relationship by using an optimization method in a pitch control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0022] FIG10 is a flowchart illustrating an example of blade stall logic judgment in a pitch control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0023] FIG11 is a schematic diagram illustrating a stall protection control strategy in a pitch control method of a wind turbine generator system according to an exemplary embodiment of the present disclosure.

[0024] FIG12 is a schematic diagram illustrating a control effect of a pitch control method for a wind turbine generator system according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] The following detailed description is provided to help the reader gain 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 clear after understanding the disclosure of the present disclosure. For example, the order of operations described herein is merely an example and is not limited to those orders set forth herein, but can be changed as will be clear after understanding the disclosure of the present disclosure, except for operations that must occur in a specific order. In addition, for greater clarity and conciseness, descriptions of features known in the art may be omitted.

[0026] The features described herein can be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided to illustrate only some of the many possible ways to implement the methods, devices, and / or systems described herein, which will become clear after understanding the disclosure of this disclosure.

[0027] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more.

[0028] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions should not be limited by these terms. Instead, these terms are used solely to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, what is referred to as a first member, first component, first region, first layer, or first portion in the examples described herein may also be referred to as a second member, second component, second region, second layer, or second portion without departing from the teachings of the examples.

[0029] In the specification, when an element (such as a layer, region, or substrate) is described as being “on,” “connected to,” or “coupled to” another element, the element may be directly “on,” “connected to,” or “coupled to” the other element, or one or more other elements may be present therebetween. Conversely, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, there may be no other elements present therebetween.

[0030] The terms used herein are only used to describe various examples and are not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular is intended to include the plural. The terms "comprise," "include," and "have" indicate the presence of the recited 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.

[0031] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure pertains after understanding the present disclosure. Unless expressly defined otherwise herein, terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and should not be interpreted in an idealized or overly formal manner.

[0032] Furthermore, in describing the examples, when it is deemed that a detailed description of well-known related structures or functions would cause ambiguous interpretation of the present disclosure, such detailed description will be omitted.

[0033] As mentioned above, in the related art, after the unit enters a stall, the power is stabilized in the low power range, and the power-based pitch control method cannot be implemented, so the stall protection effect cannot be achieved.

[0034] In addition, in related technologies, the method of judging impeller stall based on the angle of attack is not applicable to long and flexible blades. Judging stall by the angle of attack of a single section cannot characterize the status of the entire blade and cannot effectively and timely protect the unit.

[0035] In view of the above problems, the present disclosure provides a pitch control method for a wind turbine generator set, a computer device, a wind turbine generator set, and a computer-readable storage medium to solve or at least alleviate the above problems.

[0036] According to the pitch control method, computer equipment, wind turbine and computer-readable storage medium of the wind turbine generator set disclosed in the present invention, the blade roughness coefficient corresponding to the current wind speed can be determined based on the current power of the unit, and the corresponding wind speed-pitch angle relationship can be determined to determine the blade stall condition for judging blade stall. When the blade is in a stalled state, the unit pitch can be controlled according to the current wind speed data and the preset pitch control relationship, so that the blade stall can be judged and the corresponding pitch action can be made while considering the power of the unit, so as to play a role in stall protection and improve the stability and reliability of the unit.

[0037] According to a first aspect of an exemplary embodiment of the present disclosure, a method for controlling the pitch of a wind turbine generator set is provided. This method can be executed by a computer device with computational analysis capabilities, for example, in at least one of the master control systems of the wind turbine generator set's pitch control system. The computer device executing this method can be a terminal device or a server, such as a tablet computer, a laptop computer, or a digital assistant. The server can be a standalone server, a server cluster, a cloud computing platform, or a virtualization center.

[0038] In an example application scenario, a computer device that executes a pitch control method for a wind turbine generator set according to an embodiment of the present disclosure can determine a blade roughness coefficient corresponding to current wind speed data based on current power data of the wind turbine generator set, and can determine the wind speed-pitch angle relationship under the blade roughness coefficient based on a preset pitch angle condition.

[0039] The computer device can also determine the blade stall condition for the current wind speed data based on the wind speed pitch angle relationship and the current wind speed data, and can indicate that the wind turbine is in a blade stall state in response to the relationship between the current pitch angle of the wind turbine and the blade stall condition, and control the pitch of the wind turbine according to the current wind speed data and a preset pitch control relationship.

[0040] Here, the computer device can, for example, be communicatively connected to a database or a data management system, which can store measured power data, wind speed data, and pitch angle data or estimated power data, wind speed data, and pitch angle data, so that the computer device can execute the above method based on such power data, wind speed data, and pitch angle data.

[0041] According to the pitch control scheme of the wind turbine generator set disclosed in the present invention, the pitch of the set can be controlled according to the current wind speed data and the preset pitch control relationship, so that the blade stall can be judged and the corresponding pitch action can be made while considering the power of the set, so as to play the role of stall protection and improve the stability and reliability of the set.

[0042] A pitch control method for a wind turbine generator system according to an exemplary embodiment of the present disclosure may include the following steps:

[0043] As shown in FIG. 1 , in step S110 , a blade roughness coefficient corresponding to current wind speed data may be determined based on current power data of the wind turbine generator set.

[0044] Specifically, the degree of dirtiness of the blades of a wind turbine generator set will affect the power generation of the set, that is, the output power of the set, and the output power is also related to the current wind speed. Therefore, the roughness of the blades under the current wind speed can be judged based on the current power situation. Here, the roughness of the blades can refer to the degree of dirtiness of the blades. The higher the roughness, the higher the degree of dirtiness of the blades.

[0045] In this step, the roughness of the blade can be quantified and represented by a blade roughness coefficient to characterize the roughness of the blade (which can also be considered as the degree of dirtiness). The larger the coefficient is, the higher the degree of dirtiness of the blade is.

[0046] As an example, in step S110, the blade roughness coefficient corresponding to the current wind speed data may be determined in the following manner:

[0047] As shown in FIG. 2 , in step S210 , a current power characteristic quantity corresponding to the current wind speed data may be determined based on the current power data and preset power data corresponding to the current wind speed data.

[0048] Here, the current power characteristic quantity can represent the relationship between the current power data and the preset power data. For example, the current power characteristic quantity Cp_actual can be expressed by the following formula (1): Cp_actual=Power i / PowerTheory (1)

[0049] Among them, Power i Indicates the current power data, which can be collected in real time or estimated based on the current operating data. For example, multiple power data within a period of time can be collected or estimated. iIt can represent the i-th power data, where i is a positive integer; PowerTheory represents the preset power data, for example, it can be the output power predetermined for the unit and corresponding to the current wind speed data, which can be obtained by theoretical calculation.

[0050] Although the example of determining the current power characteristic quantity is described here using formula (1) as an example, the determination method is not limited to this. For example, it can also be determined by an expression obtained by modifying the above formula (for example, introducing a weighting coefficient, etc.), or it can also be determined by other expressions that can represent the relationship between the current power data and the preset power data, for example, it can be determined by the difference between the two, the square difference, etc.

[0051] It is described above that the preset power data may be predetermined theoretical power data, which may be determined according to actual needs. Here, according to an embodiment of the present disclosure, an example of determining the preset power data will be given.

[0052] As an example, the preset power data may be determined based on current environmental data, current wind speed data, and blade sweep data of the wind turbine generator set.

[0053] Specifically, the environmental data may include, for example, the air density of the area where the unit is located, and the blade swept wind data may include, for example, the blade swept wind area. The blade swept wind area refers to the blade swing range required when the impeller rotates, or the space required for the impeller to rotate. As an example, the preset power data PowerTheory can be expressed by the following formula (2): PowerTheory = k·ρ·v 3 ·S (2)

[0054] Wherein, k represents a preset coefficient, which can be set according to actual needs, for example, it can be 0.5; ρ represents the air density in the area where the unit is located; v represents the current wind speed; and S represents the swept area of ​​the unit blades.

[0055] Although the example of determining the preset power data is described here using formula (2) as an example, the determination method is not limited to this. For example, it can also be determined by an expression obtained by modifying the above formula (for example, introducing a weighting coefficient, etc.), or it can also be determined by other parameters that can represent environmental data, other parameters that can represent the current wind speed, and other parameters that can represent the blade sweeping conditions. For example, when the wind speed is the predicted wind speed, the above-mentioned wind speed term v can be replaced by an expression or model of the predicted wind speed.

[0056] By determining the preset power data in the manner of the above example, the environmental conditions of the unit and the blade sweeping conditions can be taken into consideration, and the preset power data can be determined by comprehensively considering multiple factors. Based on the preset power data determined in this way, when determining the current power characteristic quantity, the difference between the current power data and such theoretical power data can be better reflected, making the obtained current power characteristic quantity more representative.

[0057] In step S220, the blade roughness coefficient may be determined based on the current power characteristic quantity and a preset power characteristic quantity corresponding to the current wind speed data.

[0058] In this step, a preset power characteristic value can be predetermined for each wind speed. The preset power characteristic value may include a power characteristic value under one or more blade dirtiness levels. Thus, by comparing the current power characteristic value with the preset power characteristic value, the blade dirtiness level corresponding to the current power characteristic value can be determined, thereby determining the dirtiness of the current blade from a power perspective.

[0059] As an example, under each wind speed data, the preset power characteristic amount may include a first preset characteristic amount in a clean blade state and a second preset characteristic amount in a rough blade state. In this example, in step S220, the blade roughness coefficient may be determined in the following manner:

[0060] As shown in FIG3 , in step S310 , a power roughness coefficient relationship between the power characteristic quantity and the blade roughness coefficient may be determined based on the first preset characteristic quantity and the second preset characteristic quantity.

[0061] In this step, a power roughness coefficient relationship may be constructed based on the first preset feature quantity and the second preset feature quantity. For example, an interpolation method may be used to establish a power roughness coefficient relationship represented by the following formula (3): i =(Cp_actual-Cp_rough) / (Cp_design-Cp_rough) (3)

[0062] Among them, k i represents the blade roughness coefficient, Cp_actual represents the current power characteristic quantity, Cp_rough represents the second preset characteristic quantity, and Cp_design represents the first preset characteristic quantity. Here, the blade roughness coefficient is a quantitative representation of the blade roughness, which can represent the roughness ratio of the blade.

[0063] In addition, the above formula (3) uses a linear interpolation method to determine the power roughness coefficient relationship, but it is not limited to this, and other interpolation methods can also be used.

[0064] In step S320, the blade roughness coefficient corresponding to the current power characteristic quantity can be determined based on the power roughness coefficient relationship.

[0065] In this step, the current power characteristic quantity can be substituted into the power roughness coefficient relationship to obtain the blade roughness coefficient corresponding to the current power characteristic quantity.

[0066] Determining the blade roughness coefficient in the above manner takes into account the correlation between the blade roughness and the unit power. By comparing the current power characteristic quantity with the preset power characteristic quantity, the blade roughness is quantified. Compared with the non-quantitative representation of the blade roughness in the related art, the quantification of the blade roughness facilitates the introduction of the blade roughness into the control strategy of the unit.

[0067] Although it is described above that the preset power characteristic quantity includes the first preset characteristic quantity and the second preset characteristic quantity, and the process of determining the blade roughness coefficient is described by taking Equation (3) as an example, the present disclosure is not limited thereto. The preset power characteristic quantity may also include more or fewer preset characteristic quantities. For example, it may include preset characteristic quantities corresponding to more than 3 levels of blade fouling degree. Based on such preset characteristic quantities, the power roughness coefficient relationship can be obtained by interpolation, fitting, etc. to determine the blade roughness coefficient.

[0068] In addition, as an example, before performing step S110, it can also be determined whether the current rotational speed of the unit is currently in the optimal tracking section. In response to being in the optimal tracking section, step S110 can be executed to determine the blade roughness coefficient corresponding to the current wind speed data; in response to not being in the optimal tracking section, step S110 may not be executed. Here, the optimal tracking section may refer to the rotational speed state of the unit where blade stall judgment can be performed.

[0069] In this example, the pitch control method according to an embodiment of the present disclosure may further include: obtaining the current rotational speed data of the wind turbine generator set; in response to the current rotational speed data and the preset rated rotational speed of the unit satisfying the preset rotational speed relationship, performing the step of determining the blade roughness coefficient corresponding to the current wind speed data.

[0070] Here, the preset rotational speed relationship may represent the relationship between the current rotational speed data and the rated rotational speed of the unit. For example, the preset rotational speed relationship may be W < Wset, where W represents the current rotational speed data and Wset represents the rated rotational speed of the unit.

[0071] When the preset speed relationship is met, it can be considered that the unit is currently in the optimal tracking section, and the unit is in a non-stall state when operating in the optimal tracking section. The blade characteristics of the optimal tracking section can be used to determine the actual operating conditions of the blades (such as roughness), and the power characteristic quantity is calculated based on the wind speed data and power data of the optimal tracking section, and the blade stall judgment is performed, that is, step S110 can be executed; when the preset speed relationship is not met, it can be considered that the unit is not currently in the optimal tracking section, and step S110 can be not executed. In this case, the relationship between the unit speed and the unit rated speed can continue to be monitored, and step S110 is executed in response to the above-mentioned preset speed relationship being met.

[0072] In this way, whether to perform a blade stall determination can be screened based on the unit's speed, ensuring that the blade's operating status is obtained when the unit's speed is in a good state, thereby improving the accuracy of the stall determination. However, this step can also be omitted, and step S110 can be performed without distinguishing the unit's speed state.

[0073] In step S120 , the wind speed-pitch angle relationship under the blade roughness coefficient may be determined based on a preset pitch angle condition.

[0074] In this step, the preset pitch angle condition may, for example, represent pitch angle limits corresponding to different wind speeds under different roughness coefficients.

[0075] As an example, the preset pitch angle conditions may include a first wind speed and pitch angle condition corresponding to different wind speeds when the blade is in a clean state, and a second wind speed and pitch angle condition corresponding to different wind speeds when the blade is in a rough state. Specifically, the first wind speed and pitch angle condition may indicate a pitch angle limit for different wind speeds when the blade is in a clean state; and the second wind speed and pitch angle condition may indicate a pitch angle limit for different wind speeds when the blade is in a rough state.

[0076] In this example, the wind speed-pitch angle relationship under the blade roughness factor can be determined as follows:

[0077] As shown in FIG. 4 , in step S410 , a first pitch angle corresponding to current wind speed data in a blade cleaning state may be determined based on a first wind speed and pitch angle condition.

[0078] Since the first wind speed pitch angle condition may represent pitch angle limits corresponding to different wind speeds in a blade clean state, the first pitch angle corresponding to the current wind speed data may be determined.

[0079] In step S420, based on the second wind speed and pitch angle condition, a second pitch angle corresponding to the current wind speed data in the rough state of the blade may be determined.

[0080] Since the second wind speed pitch angle condition may represent the pitch angle limits corresponding to different wind speeds in the rough blade state, the second pitch angle corresponding to the current wind speed data may be determined.

[0081] In step S430, the first pitch angle and the second pitch angle may be adjusted based on the blade roughness coefficient to determine the pitch angle corresponding to the current wind speed data under the blade roughness coefficient, so as to determine the wind speed pitch angle relationship.

[0082] As an example, when the first pitch angle corresponding to the current wind speed data in the clean state of the blade and the second pitch angle corresponding to the current wind speed data in the rough state of the blade are known, the first pitch angle and the second pitch angle can be converted based on the blade roughness coefficient to obtain the pitch angle corresponding to the current wind speed data under the blade roughness coefficient.

[0083] For example, the pitch angle corresponding to the current wind speed data under the blade roughness coefficient can be expressed by the following formula (4): PitchK(i) = K × PitchDesign(i) + (1-K) × PitchRough(i) (4)

[0084] Among them, i represents the i-th wind speed data in the current wind speed data, i can be [0, m], and m is the total number of wind speed data; K represents the statistical value of the blade roughness coefficient of the m wind speed data, such as the average value; PitchK(i) represents the pitch angle corresponding to the i-th wind speed data under the blade roughness coefficient; PitchDesign(i) represents the first pitch angle corresponding to the i-th wind speed data; PitchRough(i) represents the second pitch angle corresponding to the i-th wind speed data.

[0085] Based on the above formula, the wind speed-pitch angle relationship between the i-th wind speed data and the pitch angle PitchK(i) can be determined.

[0086] Although equation (4) is used here as an example to describe an example of determining the pitch angle corresponding to the current wind speed data, its determination method is not limited to this. For example, it can also be determined by an expression obtained by modifying the above equation (for example, introducing weighting coefficients, etc.).

[0087] In addition, in the above example, the preset pitch angle condition can be predetermined according to actual needs. For example, in the example where the preset pitch angle condition includes a first wind speed pitch angle condition and a second wind speed pitch angle condition, the first wind speed pitch angle condition and the second wind speed pitch angle condition corresponding to different wind speeds can be determined respectively, for example, as shown in Table 1 below, wherein WindSpeedPitchLimitDesign represents the first wind speed pitch angle condition, WindSpeedPitchLimitRough represents the second wind speed pitch angle condition, and Windi represents the i-th wind speed, wherein i = 1, 2, 3, ..., m, and m is the total number of wind speed data.

[0088] Table 1

[0089] Based on the data in Table 1, the pitch angle PitchK(i) corresponding to the current wind speed data under the blade roughness coefficient and the wind speed pitch angle relationship WindSpeedPitchLimitK can be determined.

[0090] It should be noted that, although an example of the preset pitch angle condition is given here using Table 1 as an example, it is not limited to this. The preset pitch angle condition can also be expressed in the form of a function or other discrete data forms, as long as the pitch angle limits corresponding to different wind speeds under the corresponding roughness can be given.

[0091] In this way, the pitch angle limit corresponding to the current wind speed under the current blade state can be determined, thereby providing guidance for determining blade stall and controlling the unit pitch change.

[0092] In step S130 , a blade stall condition for the current wind speed data may be determined based on the wind speed-pitch angle relationship and the current wind speed data.

[0093] For example, blade stall can refer to the phenomenon of airflow separation on the blade surface after the blade cross-sectional angle of attack exceeds a certain critical value. In this step, the blade stall condition can represent the relationship between the current pitch angle and the pitch angle limit under the current wind speed data. Here, the blade stall condition can be determined based on the wind speed-pitch angle relationship and the current wind speed data, thereby more accurately determining whether the turbine is currently in a stall state.

[0094] For example, when determining the wind speed - pitch angle relationship WindSpeedPitchLimitK, based on the current wind speed data, the statistical values of the wind speed and pitch angle within a predetermined period of the unit operation can be obtained, such as the average wind speed per minute and the average pitch angle per minute. And based on the wind speed - pitch angle relationship WindSpeedPitchLimitK, the statistical values of the wind speed and pitch angle can be converted (such as interpolation calculation) to obtain the critical pitch angle PitchK for judging blade stall.

[0095] In this example, the blade stall condition can be PitchAvg1min < PitchK, where PitchAvg1min represents the statistical value of the pitch angle within a predetermined period of the unit operation, such as the average pitch angle per minute. When the statistical value of the pitch angle PitchAvg1min satisfies the above - mentioned blade stall condition, it can be considered that the blade is in a stall state; when the statistical value of the pitch angle PitchAvg1min does not satisfy the above - mentioned blade stall condition, it can be considered that the blade is not in a stall state.

[0096] In step S140, in response to the relationship between the current pitch angle of the wind turbine generator and the blade stall condition indicating that the wind turbine generator is in a blade stall state, the wind turbine generator can be controlled to pitch according to the current wind speed data and the preset pitch control relationship.

[0097] In this step, when the wind turbine generator is in a blade stall state, the wind turbine generator can be pitch - controlled based on the preset pitch control relationship. Here, the preset pitch control relationship can, for example, characterize the relationship between the wind speed and the pitch angle in the blade stall state, and it can be set according to actual needs. An example of determining the preset pitch control relationship will be given hereinafter with reference to FIGS. 6 and 7.

[0098] As an example, in this step S140, the wind turbine generator can be controlled to pitch in the following manner: As shown in FIG. 5, in step S510, the pitch - angle control condition can be determined according to the current wind speed data and the preset pitch control relationship; in step S520, the wind turbine generator can be controlled to pitch based on the pitch - angle control condition.

[0099] Here, the pitch - angle control condition can represent the limiting condition for the pitch angle of the wind turbine generator to pitch, and this pitch - angle control condition can be given according to actual needs. For example, the minimum pitch angle of the wind turbine generator in the blade stall state can be determined in advance.

[0100] As an example, on the basis of pitch control based on speed, pitch control based on wind speed can be added. In the event of a stall in the unit, it can be switched to wind speed-pitch angle control. The current minimum pitch angle as the pitch angle control condition is determined by the current wind speed and the preset pitch control relationship, and the pitch position output by the unit is limited. For example, the pitch angle reference value in the pitch instruction can be greater than the minimum pitch angle.

[0101] In this way, by switching to wind speed-propeller angle control when the stall state of the unit is identified, the power generation loss caused by the stall and the load risk after the blade stall can be effectively reduced.

[0102] An example of determining the preset pitch control relationship described in step S140 above will be given below with reference to Figures 6 and 7. As an example, the preset pitch control relationship may be determined in the following manner:

[0103] As shown in FIG6 , in step S610 , historical operation data of a wind turbine generator set may be obtained.

[0104] Here, the preset pitch control relationship can be optimized, taking into account differences in blade contamination and air density. Historical operating data can include historical wind speed data, historical power data, and historical pitch angle data. For example, a sampling rate of 0.1 Hz can be used to record 10-second average data points. The recorded variables can include the average wind speed, average power, and average pitch angle for 10 seconds.

[0105] In step S620, based on the historical power data, historical operation data whose power does not meet the preset power condition may be screened out to obtain screened historical operation data.

[0106] Here, the preset power condition may represent that the power is higher than the preset power. Data points whose power does not meet the preset power condition (including the average wind speed, average power, and average pitch angle of the data point) may be screened out from the historical power data.

[0107] As an example, the preset power may be a preset preset, in which case the preset power condition may be a filtering condition for the power value of the historical power data; as another example, the preset power may also be a preset percentage or percentile value or ranking, in which case the preset power condition may be a filtering condition for the percentage or percentile value or ranking of the power of the historical power data.

[0108] For example, you can get the filtered historical operation data in the following way:

[0109] As shown in FIG. 7 , in step S710 , the historical operation data may be binned based on the historical wind speed data to obtain a plurality of wind speed bins and the historical operation data corresponding to each wind speed bin.

[0110] Specifically, the optimization can be performed based on wind speed bins, so that the optimization can be performed near the transition section to reduce unit stall. For example, the wind speed range can be set to the rated wind speed ±3m / s, and the wind speed can be optimized with a step size of 1m / s. Taking the optimization range of 9m / s-15m / s as an example, Table 2 shows the results of the 9m / s wind speed bin (i.e., the wind speed is within the range of [9-0.5m / s, 9+0.5m / s]):

[0111] Table 2

[0112] Here, the number of data points in each wind speed bin can be greater than a preset number, for example, 200 (i.e., each bin contains approximately 30 minutes of data), or the sum of the number of data points in each wind speed bin can be greater than 200 × n × 2 points, where n is the number of wind speed bins. If a wind speed bin contains fewer than 200 data points, the bin is discarded.

[0113] In step S720, the historical operating data in each wind speed bin may be sorted based on the historical power data, and the historical operating data whose power does not meet the preset power condition may be screened out to obtain the screened historical operating data.

[0114] In this step, it can be considered that the historical power data that does not meet the preset power conditions in each wind speed bin has a certain stall situation. Therefore, the historical operating data that does not meet the preset power conditions can be screened out.

[0115] As an example, the data in each wind speed bin can be sorted from small to large based on power, divided using the quartile method, and the data points in the lower quartile are eliminated. It is assumed that there is a certain stall situation in the lowest quartile power in the bin, and 75% of the high-power data points are retained to obtain the historical operating data after screening.

[0116] In step S630, based on the filtered historical operating data, the average wind speed and the average pitch angle of each wind speed bin may be determined as a preset pitch control relationship.

[0117] For the historical operating data after screening, the pitch angle and wind speed corresponding to the high power point in each wind speed bin can be averaged respectively to obtain the average wind speed and pitch angle of each wind speed bin, thereby determining the preset variable pitch control relationship as the blade stall protection and whole-machine pitch angle control strategy parameters of the unit.

[0118] In this way, the filtered historical operating data is obtained and the preset pitch control relationship is determined. The historical operating data that may have stall conditions can be filtered out, and more reliable historical operating data can be retained to determine the preset pitch control relationship, thereby improving the unit pitch control effect.

[0119] In addition, in the example of determining the preset pitch control relationship based on the above method, in step S510, as an example, the pitch angle control condition can be determined in the following manner:

[0120] As shown in FIG8 , in step S810 , a target wind speed average value related to current wind speed data among wind speed average values ​​of multiple wind speed bins may be determined.

[0121] In this step, a target wind speed average value associated with the current wind speed data can be determined from the wind speed average values ​​of the multiple wind speed bins based on a preset pitch control relationship. As an example, the target wind speed average value can be the same wind speed as the current wind speed data, or can include two wind speeds closest to the current wind speed data, i.e., a first wind speed average value closest to the current wind speed data among the wind speed average values ​​greater than the current wind speed data, and a second wind speed average value closest to the current wind speed data among the wind speed average values ​​less than the current wind speed data.

[0122] In step S820, a target pitch angle corresponding to the current wind speed data may be determined based on the average value of the pitch angle corresponding to the average value of the target wind speed.

[0123] In an example where the target wind speed average value may be the same wind speed as the current wind speed data, the pitch angle average value corresponding to the target wind speed average value may be determined as the target pitch angle corresponding to the current wind speed data.

[0124] In an example where the target wind speed average value may include a first wind speed average value and a second wind speed average value, a first pitch angle average value corresponding to the first wind speed average value and a second pitch angle average value corresponding to the second wind speed average value may be converted to obtain a target pitch angle corresponding to the current wind speed data. For example, the first pitch angle average value and the second pitch angle average value may be interpolated to obtain the target pitch angle.

[0125] In step S830 , a pitch angle control condition may be determined based on the target pitch angle.

[0126] Here, the pitch angle control condition may represent that the minimum pitch angle of the pitch control is the target pitch angle. Specifically, the target pitch angle determined above may be used as the minimum pitch angle of the pitch control to generate the pitch angle control condition.

[0127] By determining the pitch angle control conditions in this way, the pitch angle limit of the variable pitch control can be analyzed by statistically analyzing historical operating data, thereby reducing the power loss caused by the stall even in the case of blade stall.

[0128] Based on the embodiment of the pitch control method of the wind turbine generator set described above, an example process of determining a preset pitch control relationship by an optimization method according to an exemplary embodiment of the present disclosure will be described below with reference to FIG. 9 .

[0129] In step S910 , an enable flag for determining whether to execute stall protection control may be detected. For example, when the enable flag WsPaOptEnable=true, the stall protection control logic may begin to be executed.

[0130] In step S920, the optimization action may be triggered periodically on a monthly basis, and the optimization begins. For example, if the optimization flag OptEndflag = false, step S1130 may be executed.

[0131] In step S930, the wind speed and pitch angle parameters can be switched to, and in step S940, it can be determined whether the 3s average wind speed is within the preset range [Vmin, Vmax]. Here, the preset range can be set according to actual needs. In response to the 3s average wind speed being within the preset range [Vmin, Vmax], step S950 can be executed; in response to the 3s average wind speed not being within the preset range [Vmin, Vmax], the process returns to step S910.

[0132] In step S950 , data may be recorded. For example, average values ​​for 10 seconds may be sampled at a frequency of 0.1 Hz. The average values ​​may include average wind speed, average power, average pitch angle, and air density.

[0133] In step S960, the wind speed can be divided into bins according to the wind speed. For example, the number of bins n can be calculated according to a step size of 1 m / s. The data points in each bin (for example, Nbin1, Nbin2 to Nbinn) may include power data (for example, Power1, Power2 to Powern), wind speed data (for example, Wind1, Wind2 to Windn) and pitch angle data (for example, Pitch1, Pitch2 to Pitchn).

[0134] In step S970, it can be determined whether the number of data points in each sub-bin is greater than a preset threshold N, for example, N can be 200, or it can be determined whether the total number of data points in all sub-bins is greater than N × n × 2. In response to the condition being met in step S970, step S980 can be executed; in response to the condition not being met in step S970, the process can return to step S950.

[0135] In step S990, data matrix processing can be performed on the binned data. Specifically, data sorting can be performed, for example, sorting can be performed according to power value from small to large; data elimination can be performed on the sorted data, for example, the lower quartile data can be eliminated to obtain the power-wind speed-pitch angle matrix [Power, Wind, Pitch] in each wind speed bin. Here, in response to Nbini<200 of the data bin, the data bin can be discarded; data processing can be performed on the eliminated data, for example, the array variables in each wind speed bin can be averaged to obtain the power average value-wind speed average value-pitch angle average value matrix [PowerAvgi, WindAvgi, PitchAvgi].

[0136] In step S9100, the obtained wind speed average WindAvgi and pitch angle average PitchAvgi can be used as the final preset pitch control relationship. At this point, the preset pitch control relationship can be recorded, and in step S9110, the optimization can be ended, for example, the optimization flag ptEndflag can be set to true.

[0137] Based on the embodiment of the pitch control method of the wind turbine generator set described above, an example process of blade stall logic judgment according to an exemplary embodiment of the present disclosure will be described below with reference to FIG. 10 .

[0138] As shown in FIG10 , in step S1010 , the average values ​​for 1 minute may be recorded. The average values ​​may include: the average value of the rotation speed W of the wind turbine generator set, the average value of the power, the average value of the pitch angle pitch, and the average value of the wind speed windspeed.

[0139] In step S1020, it is determined whether the speed is in the optimal tracking section. For example, it is determined whether W < Wset, where W represents the one-minute average speed value and Wset represents the rated speed of the unit. If it is not in the optimal tracking section, the process returns to step S1010 and continues to record the one-minute average value. If it is in the optimal tracking section, step S1030 is executed.

[0140] In step S1030, the current power characteristic value of the computer group can be calculated, for example, using the formula (1) described above: Cp_actual=Power i / PowerTheory is calculated, wherein PowerTheory can be calculated using the formula (2) described above: PowerTheory = k·ρ·v 3 ·S is used for calculation.

[0141] In step S1040, the blade roughness coefficient k can be calculated based on the current power characteristic value and the preset power characteristic value. iAnd the number of data points m can be recorded. For example, the above-described formula (3) can be used: k i =(Cp_actual-Cp_rough) / (Cp_design-Cp_rough) to calculate the blade roughness coefficient.

[0142] In step S1050, it can be determined whether the number m of data points reaches a preset threshold, which can be, for example, 100. If the preset threshold is not reached, the process returns to step S1010 to continue recording the average value for 1 minute; if the preset threshold is reached, step S1060 can be executed.

[0143] In step S1060, the blade roughness coefficient K can be calculated. The blade roughness coefficient K can be the roughness coefficient k of each blade. i The average value of .

[0144] In step S1070, the wind speed-pitch-angle relationship under the blade roughness coefficient may be calculated. The wind speed-pitch-angle relationship may be, for example, the WindSpeedPitchLimitK given in Table 1 above.

[0145] In step S1080, the current operating status of the computer group may be calculated, for example, the average wind speed value WindAvg1min within 1 minute and the average pitch angle value PitchAvg1min within 1 minute may be calculated.

[0146] In step S1090, based on the relationship between wind speed and pitch angle under the blade roughness coefficient, the minimum pitch angle PitchK of the stall critical state can be obtained by interpolation according to the current wind speed (for example, the wind speed average WindAvg1min).

[0147] In step S10100, it can be determined whether the average pitch angle PitchAvg1min is less than the minimum pitch angle PitchK. If it is less than the minimum pitch angle PitchK, it can be considered that the blade is in a stalled state; if it is not less than the minimum pitch angle PitchK, it can be considered that the blade is not stalled.

[0148] Although the steps are described above in an exemplary manner, the execution order of the steps is not limited to the order shown in the drawings and described above. For example, step S1080 can be executed at any time after step S1010 and before step S1090.

[0149] Based on the above-described embodiment of the pitch control method for a wind turbine generator set, an example process flow of stall protection control logic according to an exemplary embodiment of the present disclosure will be described below with reference to FIG11. FIG9 is a flow chart illustrating an example of determining a preset pitch control relationship by an optimization method in the pitch control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0150] Based on the embodiment of the pitch control method of the wind turbine generator set described above, an example process of a control strategy according to an exemplary embodiment of the present disclosure will be described below with reference to FIG. 11 .

[0151] As shown in Figure 11, at operation 1111, the current wind speed, power, rotational speed, and pitch angle data of the turbine can be input. At operation 1112, based on this data and the method for determining blade stall described above, a determination can be made as to whether the turbine is currently in a stalled state. If the turbine is not in a stalled state, the process returns to operation 1111; if the turbine is in a stalled state, operation 1113 can be executed.

[0152] At operation 1113, the preset pitch control relationship described above can be queried to obtain the optimal control limit for the pitch angle under the current wind speed data. At operation 1114, the pitch angle control conditions can be obtained, for example, the minimum pitch angle for controlling the turbine's pitch under the current wind speed data and blade roughness coefficient can be obtained.

[0153] On the other hand, in operation 1121, the speed data of the turbine can be input, and in operation 1122, a pitch control strategy such as an existing pitch proportional integral derivative (PID) control can be used to obtain a pitch position request in operation 1123. In operation 1124, the pitch position request can be limited based on the pitch angle control condition obtained in operation 1114, thereby obtaining a final pitch position in operation 1125 for controlling the turbine pitch.

[0154] Figure 12 shows an example of an optimal control power curve optimization result obtained by using the pitch control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure for stall protection. As shown in Figure 12, after power optimization is performed using the pitch control method according to an exemplary embodiment of the present disclosure, the power curve of the unit shows a significant improvement near the rated wind speed compared to power optimization without using this method. Figure 12 is intended to illustrate a trend comparison of the power curves between using this method and not using this method, and therefore the specific values ​​of the horizontal and vertical axes are not shown.

[0155] It can be seen that compared with the traditional variable pitch control unit which has serious power loss after stall, this method maximizes the unit output power and reduces the power generation loss after stall by optimizing the relationship between wind speed and pitch angle of a single unit.

[0156] According to the variable pitch control method of the embodiment of the present disclosure, a more reasonable relationship between wind speed and pitch angle can be established based on the operating data of the unit itself for use in stall protection of the blades, and the stall state of the unit can be effectively identified. After the stall, it switches to wind speed-pitch angle control, which can effectively reduce the power generation loss caused by the stall and the load risk of the blades after the stall.

[0157] In addition, according to the pitch control method of the embodiment of the present disclosure, the roughness ratio of the current state of the blade is defined through the data of the unit in the optimal operating section, so as to give a preset pitch control relationship between wind speed and pitch angle, which is used as the basis for stall judgment to evaluate whether the blade is stalled. The stall state of the unit can be effectively identified, and pitch control can be performed through wind speed to carry out stall protection control in a timely manner.

[0158] According to a second aspect of the present disclosure, a computer device is provided, 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, prompt the at least one processor to execute the pitch control method for a wind turbine generator set according to the exemplary embodiment of the present disclosure.

[0159] As an example, the computer device may be arranged in the wind turbine, or the computer device may be connected to a control system of the wind turbine.

[0160] As an example, the computer device can be a PC, a tablet device, a personal digital assistant, a smart phone, or other device capable of executing the above-mentioned instruction set. Here, the computer device is not necessarily a single electronic device, but can also be any collection of devices or circuits capable of executing the above-mentioned instructions (or instruction sets) individually or in combination. The computer device can also be part of an integrated control system or system manager, or can be configured as a portable electronic device that is interconnected with a local or remote (e.g., via wireless transmission) interface.

[0161] 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, a processor may also include an analog processor, a digital processor, a microprocessor, a multi-core processor, a processor array, a network processor, etc.

[0162] The processor can execute instructions or codes stored in the memory, wherein the memory can also store data. Instructions and data can also be sent and received over the network via the network interface device, wherein the network interface device can use any known transmission protocol.

[0163] The memory may be integrated with the processor, for example, by placing RAM or flash memory within an integrated circuit microprocessor or the like. Furthermore, the memory may comprise a separate device, such as an external disk drive, a storage array, or any other storage device usable by a database system. The memory and processor may be operatively coupled or may be in communication with each other, for example, via an I / O port, a network connection, or the like, such that the processor can access files stored in the memory.

[0164] In addition, 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.

[0165] According to a third aspect of the present disclosure, a wind turbine generator set is provided. The wind turbine generator set may include the computer device according to the embodiment of the present disclosure.

[0166] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided. When instructions in the computer-readable storage medium are executed by at least one processor, the at least one processor is prompted to execute the pitch control method of a wind turbine generator set according to the exemplary embodiment of the present disclosure.

[0167] The pitch control method of a wind turbine generator set according to an embodiment of the present disclosure can be written as 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 disk storage, hard disk drive (HDD), solid state drive (SSD), card storage (such as, multimedia card, secure digital (SD) card or ultra fast 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, any other device configured to store the 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 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 on a networked computer system so 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.

[0168] The specific implementation methods 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 may be modified and varied without departing from the principles and spirit of the present disclosure, the scope of which is 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 set, the pitch control method comprising: Based on the current power data of the wind turbine generator set, determining a blade roughness coefficient corresponding to the current wind speed data; Based on a preset pitch angle condition, determining a wind speed pitch angle relationship under the blade roughness coefficient; determining a blade stall condition for the current wind speed data based on the wind speed pitch angle relationship and the current wind speed data; In response to the relationship between the current pitch angle of the wind turbine generator set and the blade stall condition indicating that the wind turbine generator set is in a blade stall state, the wind turbine generator set is controlled to change pitch according to the current wind speed data and a preset pitch control relationship.

2. The pitch control method according to claim 1, wherein: The step of determining the blade roughness coefficient corresponding to the current wind speed data based on the current power data comprises: Based on the current power data and the preset power data corresponding to the current wind speed data, determining a current power characteristic quantity corresponding to the current wind speed data, wherein the current power characteristic quantity represents a relationship between the current power data and the preset power data; The blade roughness coefficient is determined based on the current power characteristic quantity and a preset power characteristic quantity corresponding to the current wind speed data.

3. The pitch control method according to claim 2, wherein: The preset power characteristic quantity includes a first preset characteristic quantity in a clean state of the blade and a second preset characteristic quantity in a rough state of the blade, wherein the blade roughness coefficient is determined by: Based on the first preset characteristic quantity and the second preset characteristic quantity, determining a power roughness coefficient relationship between the power characteristic quantity and the blade roughness coefficient; Based on the power roughness coefficient relationship, the blade roughness coefficient corresponding to the current power characteristic value is determined.

4. The pitch control method according to claim 2 or 3, wherein: The preset power data is determined by: The preset power data is determined based on the current environmental data, the current wind speed data and the blade sweep data of the wind turbine generator set.

5. The pitch control method according to claim 1, wherein: The preset pitch angle condition includes a first wind speed pitch angle condition corresponding to different wind speeds in a clean blade state and a second wind speed pitch angle condition corresponding to different wind speeds in a rough blade state, wherein the wind speed pitch angle relationship under the blade roughness coefficient is determined by the following method: Based on the first wind speed and pitch angle condition, determining a first pitch angle corresponding to the current wind speed data in a blade cleaning state; Based on the second wind speed pitch angle condition, determining a second pitch angle corresponding to the current wind speed data in a blade rough state; Based on the blade roughness coefficient, the first pitch angle and the second pitch angle are adjusted to determine the pitch angle corresponding to the current wind speed data under the blade roughness coefficient, so as to determine the wind speed pitch angle relationship.

6. The pitch control method according to claim 1, wherein: The preset pitch control relationship is determined by: Acquiring historical operation data of the wind turbine generator set, wherein the historical operation data includes historical wind speed data, historical power data, and historical pitch angle data; Based on the historical power data, historical operation data whose power does not meet a preset power condition is screened out to obtain the screened historical operation data, wherein the preset power condition indicates that the power is higher than a preset power; Based on the filtered historical operating data, the average wind speed and the average pitch angle of each wind speed bin are determined as the preset variable pitch control relationship.

7. The pitch control method according to claim 6, wherein: The filtered historical operation data is obtained by: Binning the historical operation data based on the historical wind speed data to obtain a plurality of wind speed bins and historical operation data corresponding to each wind speed bin; The historical operating data in each wind speed bin is sorted based on the historical power data, and the historical operating data whose power does not meet the preset power condition is screened out to obtain the screened historical operating data.

8. The pitch control method according to claim 7, wherein: The step of controlling the pitch change of the wind turbine generator set according to the current wind speed data and the preset pitch change control relationship comprises: Determining a pitch angle control condition according to the current wind speed data and a preset pitch control relationship, wherein the preset pitch control relationship represents a relationship between wind speed and pitch angle in a blade stall state; Based on the pitch angle control condition, the wind turbine generator set is controlled to change pitch.

9. The pitch control method according to claim 8, wherein: The pitch angle control condition is determined by: Determine a target wind speed average value associated with the current wind speed data among the wind speed average values ​​of the plurality of wind speed bins; Determining a target pitch angle corresponding to the current wind speed data based on an average pitch angle value corresponding to the target wind speed average value; Based on the target pitch angle, the pitch angle control condition is determined, wherein the pitch angle control condition indicates that the minimum pitch angle for pitch control is the target pitch angle.

10. The pitch control method according to claim 1, wherein: The pitch control method further includes: Acquiring current rotation speed data of the wind turbine generator set; In response to the current rotation speed data and the preset rated rotation speed of the unit satisfying a preset rotation speed relationship, the step of determining the blade roughness coefficient corresponding to the current wind speed data is performed.

11. The pitch control method according to claim 1, wherein: The preset pitch angle condition represents the pitch angle limit corresponding to different wind speeds under different roughness coefficients, and the blade stall condition represents the relationship between the current pitch angle and the pitch angle limit under the current wind speed data.

12. A computer device, comprising: at least one processor; at least one memory storing computer executable instructions, Wherein, when the computer executable instructions are executed by the at least one processor, the at least one processor is prompted to execute the variable pitch control method for a wind turbine generator set as described in any one of claims 1-11.

13. A wind turbine generator set comprising the computer device according to claim 12.

14. A computer-readable storage medium, when instructions in the computer-readable storage medium are executed by at least one processor, prompting the at least one processor to execute the pitch control method of a wind turbine generator set according to any one of claims 1 to 11.

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