Controlling a wind turbine using blade pitch angle settings and blade add-on settings

Abstract

A method of controlling a wind turbine (1060) by adjusting a blade pitch angle of at least one wind turbine rotor blade (1063) having a blade add-on (1067) and at least one blade add-on is described, the method comprising adjusting the settings of the add-on (1067) to meet a control objective while temporarily maintaining the settings of the blade pitch angle.

Description

Technical Field

[0001] This invention relates to a method and apparatus for controlling a wind turbine by adjusting the blade pitch angle of at least one rotor blade with a blade attachment and at least one blade attachment. Furthermore, this invention relates to a wind turbine including the apparatus. Background Technology

[0002] Conventionally, the rotational speed of a wind turbine is controlled by adjusting the blade pitch angle of the rotor blades. In particular, at wind speeds above the rated speed, the blade pitch angle may be adjusted to a higher value to keep the rotor speed at the nominal speed.

[0003] However, making blades pitchable involves some drawbacks, including high loads on the blade pitch bearings and on the hydraulic or electric pitch system. The loading of these subsystems or components can be a critical design driver and can increase the cost of the wind turbine. Therefore, it is desirable to introduce concepts that result in less wear on these subsystems or components.

[0004] Therefore, a method and corresponding apparatus may be needed for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade with a blade attachment and at least one blade attachment. Summary of the Invention

[0005] According to an embodiment of the present invention, a method is provided for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade having a blade attachment and at least one blade attachment, the method comprising: adjusting the setting of the attachment to meet a control objective while temporarily maintaining the setting of the blade pitch angle.

[0006] This method can be performed, for example, by a module of the wind turbine control or wind turbine controller. It can be applied specifically for wind speeds above the nominal wind speed and / or when the output power (or torque) reaches or is at the nominal value or setpoint. The method can also be performed, for example, during idling, such as when the wind turbine is not supplying electricity to the utility grid and / or when the rotor has a very low rotational speed.

[0007] Blade attachments can be constructed in various ways. Blade attachments can be considered to include active attachments, meaning attachments that can be modified or adjusted in terms of their aerodynamic properties. Attachments can be mounted on or at least exposed on the surface of the rotor blades. Attachments can be constructed, for example, as spoilers (one or more segments) or as flaps (e.g., trailing edge flaps) mounted, for example, at the tips and / or trailing edges of the rotor blades, covering radial sections, for example, extending from beyond the midpoint of the span to near the blade tip.

[0008] According to embodiments of the invention, adjustable or active blade attachments can be used to control wind turbines, particularly to achieve desired rotational speeds even at wind speeds above the rated or nominal speed. Furthermore, primarily according to embodiments of the invention, the blade attachments can be adjusted without simultaneously adjusting the blade pitch angle. This reduces or even eliminates the load on blade pitch adjustment components (such as gears, pitch actuators, etc.).

[0009] Specific actuators involving hydraulic and / or pneumatic and / or electric actuators may be employed to adjust the blade attachment. The attachment may, for example, comprise multiple spoiler segments arranged side-by-side along the longitudinal direction of the rotor blades on the surface of the rotor blades. Each of these spoiler segments can be actuated independently of the others. Each segment can, for example, be adjusted to be on and / or off, which corresponds, for example, to the outward or inward rotation of the moving surface. The flaps may also rotate inward or outward to varying degrees.

[0010] Adjusting blade attachments can affect the driving impact of impinging winds, which refers to the driving impact on the rotational speed or torque of the rotor blades applied to the rotor shaft of a wind turbine. Therefore, by adjusting blade attachments, the rotational speed of, for example, the wind turbine rotor can be controlled, particularly or at least within a specific range for a given (fixed) blade pitch angle.

[0011] Adjusting the settings of the attachments will affect the airflow across the rotor blade surface, thereby affecting the mechanical torque generated due to the alteration of the rotor blade surface or the change in airflow as it flows across the outer surface of the rotor blades. Consequently, the torque acting on the wind turbine rotor is also altered, thus affecting the rotor speed.

[0012] When the control objective can be met simply by adjusting the blade attachments without adjusting the blade pitch angle, the wear and load on the components of the blade pitch system can be reduced, thus extending the service life of those components.

[0013] Temporarily maintaining the blade pitch angle setting may (primarily) involve applying adjustment blade attachments to control or achieve a target. If the target cannot be met by exclusively adjusting the attachments, the blade pitch angle can support it with fewer requirements, for example, only when the blade attachments are saturated at their limits should the pitch be adjusted and / or the blade pitch adjusted more slowly / very little to bring the blade attachments to the correct operating point (e.g., ensuring that they do not remain saturated, but are moved to a position where they can be controlled for increasing and decreasing speeds / winds).

[0014] During control, the blade pitch angle setting can be temporarily maintained, but it is used in other ways to ensure excess capacity in the blade attachment setting by adapting to the current operating point and, in some cases, assisting the blade attachment setting in achieving control objectives.

[0015] The control objective may, for example, involve achieving a specific rotor speed, and / or achieving a specific rotor blade torque and / or achieving a specific power output. In other embodiments, the control objective may involve setting a specific reduction (i.e., reducing power below the available power). In these and other embodiments, the method may be applied, for example, to wind speeds below (or even above) the nominal wind speed. The method can be applied whenever it is possible to achieve the control objective by primarily or only adjusting the blade attachments without also adjusting the blade pitch angle.

[0016] The controllability of active blade attachments can lead to less pitch and / or better control for different control objectives. This is particularly applicable when the control objective is rotor speed.

[0017] According to embodiments of the invention, an add-on controller and a pitch angle controller are employed to implement the method. These controllers can be implemented, for example, using conventional PI controllers.

[0018] Wind turbine blades may be fitted with active aerodynamic devices (also referred to herein as attachments) that can affect the aerodynamic properties of the rotor blades. However, conventionally, blade attachments may not be used to control wind turbines, and in particular, not to control rotational speed.

[0019] According to an embodiment of the present invention, the control objective includes achieving and / or tracking a reference rotational speed of a rotor with blades mounted, wherein the adjustment of the setting of the attachment is based on a rotational speed error, which is the difference between the reference rotational speed and the actual rotational speed.

[0020] Achieving and / or tracking a reference speed may include keeping the speed (which may fluctuate due to random wind) close to the reference speed.

[0021] The reference speed can correspond to a preset value, for example, derived from the mechanical / electrical / aerodynamic configuration of the wind turbine. The reference speed can, for example, correspond to the design speed at which the wind turbine will operate during normal production operations. The actual speed can be measured and / or estimated, for example, based on electrical quantity. Thus, conventionally available quantities can be utilized to implement this method.

[0022] According to an embodiment of the invention, the method further includes: adjusting the blade pitch angle based on the rotational speed error and the add-on setting displacement, the add-on setting displacement being the difference between a (reference or actual) add-on setting and a nominal add-on setting, wherein the blade pitch angle is adjusted only if the add-on setting displacement is greater than a displacement threshold and / or the add-on setting is closer to at least one add-on setting limit than at least one limit threshold. For example, if the difference between the add-on setting and the add-on setting limit (e.g., remaining capacity) is less than the limit threshold (a threshold regarding remaining capacity), the blade pitch angle can be adjusted because in this case, the add-on may not have sufficient capacity for further adjustment as it is close to its final adjustment position.

[0023] Adjusting the blade pitch angle may involve rotating the rotor blades about a longitudinal axis. The attachment may be associated with a setting where the attachment should be in operation under normal conditions. A nominal attachment setting may, for example, correspond to a setting where the attachment has 50% of its effect on aerodynamic properties or on the total capacity of the airflow around the wind turbine blades. In other embodiments, the nominal attachment setting may, for example, correspond to a total disconnection state of the attachment, which corresponds to zero or only a very small effect on the airflow compared to the airflow of rotor blades without the attachment. According to other embodiments, the nominal attachment setting may correspond to a desired attachment setting that may exist during normal operation of the wind turbine.

[0024] The nominal add-on setting can also be referred to as the add-on setpoint. The add-on setpoint can be calculated based on the available add-on capacity and the requested add-on utilization factor. Therefore, the utilization factor can be or may include:

[0025] •constant,

[0026] • A function of turbulence intensity. It may have a conservative value (low setpoint) in highly turbulent conditions, thus allowing for greater capacity in the add-on to cope with increased wind speed, which can lead to increased rotational speed and thus overspeed avoidance. In this case, a decrease in rotational speed may result in a less significant possible decrease in power.

[0027] • Functions of turbine operating values, such as power generation, idling status, blade load sensor calibration status, rotor balance estimation, or any other turbine status that affects the choice between overspeed avoidance and power generation.

[0028] Therefore, the nominal add-on setting (also known as the add-on setpoint) can depend on the specific operating conditions of the wind turbine and environmental factors such as wind turbulence and / or wind speed. According to a specific implementation of the method, the nominal add-on setting can be set as a constant, particularly or at least within a predetermined turbulence range and / or within a predetermined range of wind turbine operating parameters.

[0029] If the attachment setting displacement is relatively large, the attachment setting deviates significantly from the nominal attachment setting. In this case, further adjustments to the attachment (at least in a specific direction toward the attachment setting limits) may no longer be possible, or may only be possible within a certain margin. In this situation, it is advantageous to also adjust the blade pitch angle, particularly in such a way that the attachment setting can be readjusted to more closely approach the nominal attachment setting again. Therefore, adjusting the blade pitch angle does not preclude (later) readjustment of the attachment, particularly toward the nominal attachment setting. The displacement threshold may be set as a constant, for example, or it may depend on environmental conditions such as wind turbulence and / or wind speed and / or wind turbine operating data. The limit threshold may also be set depending on the application.

[0030] The attachment setting limits define the attachment's setting beyond which further movement is impossible. Therefore, the attachment setting limits define the adjustment boundaries of possible adjustments to the attachment, making it impossible to adjust the attachment beyond these boundaries. For example, minimum and maximum attachment setting limits can be defined. If the attachment setting is closer to at least one attachment setting limit than at least one limit threshold (i.e., the difference between the attachment setting and the attachment setting limit is less than the limit threshold), it indicates that the attachment cannot be sufficiently adjusted to achieve the control objective. In this case, it is advantageous to control the blade pitch angle instead or additionally. Generally, adjusting the blade pitch angle has a greater effect on torque or speed than adjusting the attachment.

[0031] According to an embodiment of the invention, the nominal add-on setting corresponds to a setting from which the add-on can be adjusted in two different / opposite directions (e.g., across a similar setting range), which have different / opposite aerodynamic effects on blade-wind interaction and / or wind driving force and / or airflow around the blade.

[0032] When the attachment is in its nominal attachment setting, it can be adjusted to increase or decrease the torque generated by the air flowing around the rotor blade surface and the attachment, thereby effectively controlling the rotational speed. Therefore, attempting to keep the attachment in its nominal attachment setting advantageously ensures the possibility of controlling the rotational speed upwards and downwards as needed. This improves the control of the rotational speed.

[0033] According to an embodiment of the present invention, the method further includes: using a first function to calculate an attachment-set displacement related control quantity based on the attachment-set displacement, wherein adjusting the blade pitch angle based on the attachment-set displacement includes adjusting the blade pitch angle based on the attachment-set displacement related control quantity.

[0034] The 'additional component set displacement related control quantity' can be considered as a quantity that depends on or is a function of the additional component set displacement. Thus, the first function can be utilized. The first function can be implemented in different ways. In the first function, it can be implemented to avoid adjusting the blade pitch angle (unless the additional component set displacement is relatively large), thereby reducing the load on the blade pitch angle adjustment equipment. By defining the first function, a high degree of flexibility is provided for implementing this method to meet specific application requirements.

[0035] According to an embodiment of the present invention, the method further includes: using a second function to calculate a 'speed error-related control quantity' based on the speed error, wherein adjusting the blade pitch angle based on the speed error includes adjusting the blade pitch angle based on the 'speed error-related control quantity'.

[0036] The 'speed error-related control quantity' can be considered as a quantity that depends on the speed error or is a function of the speed error. This second function allows for flexible implementation and, in particular, allows for adjustment of the blade pitch angle only in cases where the speed error is relatively large, or at least has a value that cannot be reduced by adjusting the blade attachment (only). For example, for relatively small speed errors, the speed error-related control quantity may, for example, be zero. Only for speed errors greater than, for example, a speed error threshold, can the speed error-related control quantity be different from zero. Only in those cases can the blade pitch angle be adjusted, while for speed errors less than the speed error threshold, blade pitch angle adjustment may not be performed. In this document, speed error can refer to the absolute value of the difference between the reference speed and the actual speed (which can be positive or negative) (i.e., always positive or zero). This reduces the load and wear on the blade pitch angle adjustment equipment.

[0037] According to an embodiment of the present invention, the method further includes: calculating at least one 'addition setting related control quantity' based on the addition setting using a third function including at least one addition setting limit; calculating 'speed error and addition related control quantity' based on the speed error and the addition setting related control quantity using a second function; wherein adjusting the blade pitch angle based on the speed error includes adjusting the blade pitch angle based on the 'speed error and addition related control quantity'; wherein the addition setting limit specifically defines a boundary setting beyond which the setting cannot be increased or decreased.

[0038] When calculating the control quantity related to the add-on setting based on the add-on setting, the capacity of the add-on is also considered, that is, whether the add-on can be further adjusted to meet the control objective. Thus, a third function including at least one add-on setting limit (particularly the maximum add-on setting limit and the minimum add-on setting limit) can be used. This capacity information can then be advantageously used to calculate the control quantity related to the speed error. Therefore, it can be implemented such that not only when the speed error is relatively small, but also when, for example, it is found that the add-on still has sufficient capacity to perform speed control on its own, adjustment of the rotor blade pitch angle is avoided. Furthermore, it can thus be implemented such that when the speed error is relatively large, and further, when the capacity of the blade add-on is insufficient to achieve the control objective, the rotor blade pitch angle is actually adjusted.

[0039] According to an embodiment of the present invention, the method includes: supplying a speed error to a speed add-on controller, the speed add-on controller outputting a reference add-on setting; supplying the reference add-on setting and a nominal add-on setting to a difference element to calculate an add-on setting displacement; applying a first function to the add-on setting displacement to obtain an add-on setting displacement-related control quantity; applying a second function at least to the speed error to obtain a speed error-related control quantity; and supplying the add-on setting displacement-related control quantity and the speed error-related control quantity to a speed-pitch controller, the speed-pitch controller outputting a reference blade pitch angle.

[0040] Thus, a specific control scheme for implementing the method is provided. Other control schemes can be derived and are also within the scope of the invention, implementing the functions described above in different embodiments. The add-on controller and the pitch controller can be implemented, for example, as PI controllers. All quantities can be physically implemented as optical and / or electrical and / or electronic and / or wireless signals, and can be supplied using conductive wires, optical wires, as appropriate. The method can generally be implemented in software and / or hardware. For example, the first function and / or the second function and / or the third function can be implemented as software modules. The blade pitch actuator can be supplied with a reference blade pitch angle, thereby causing the actuator to adjust the blade pitch angle of the rotor blades accordingly. The add-on actuator can be supplied with a reference add-on setting, which can cause the actuator to adjust or move the add-on (or at least its moving surface) to apply or adjust the add-on setting.

[0041] According to an embodiment of the present invention, the method further includes: applying a third function to a reference attachment setting to obtain an attachment setting-related control quantity; further applying a second function to the attachment setting-related control quantity and a speed error to obtain a 'speed error and attachment setting-related control quantity'; and applying the 'attachment setting displacement-related control quantity' and the 'speed error and attachment setting-related control quantity' to a speed-pitch controller, which outputs a reference blade pitch angle.

[0042] The first function acts on the add-on setting displacement, that is, on the difference between the reference (or actual) add-on setting and the nominal add-on setting. The second function acts at least on the speed error, but may also additionally act on the add-on setting-related control quantity. This add-on setting-related control quantity can capture whether the add-on still has adjustment capacity to complete the control function. 'Speed ​​error and add-on setting-related control quantity' can represent both the speed error and the add-on setting-related control quantity. Therefore, this quantity is suitable for implementing considerations of both the speed error and the add-on setting capacity. In this case, the pitch controller can obtain or supply two error values ​​as input signals. The pitch controller (e.g., a PI controller) can be implemented, for example, to operate on the sum (or weighted sum) of the error inputs. In other embodiments, the two error inputs can be processed in parallel, and the results of the two parallel branches can be added at the end.

[0043] According to an embodiment of the present invention, the first function and / or the second function includes at least one of the following: a 1-dimensional or 2-dimensional gain scheduling function; a dead-time function.

[0044] Gain scheduling functions and dead-time functions can provide different implementations of different functions. This achieves high flexibility. For relatively simple implementations, the dead-time function can be used for both the first and second functions.

[0045] According to embodiments of the present invention, the dead-time function includes a first linear segment with a positive slope up to a first error value, a horizontal segment extending beyond the first error value up to a second error value, and a second linear segment with a positive slope extending beyond the second error value. The first error value, the second error value, and the slope value can be defined or set depending on the specific application. More complex functions can be implemented using 2D gain scheduling.

[0046] According to an embodiment of the invention, the gain scheduling function includes a first nonlinear segment with a positive slope (and / or monotonically increasing, including, for example, being horizontal at the beginning for large errors) up to a first error value, a horizontal segment exceeding the first error value up to a second error value, and a second nonlinear segment with a positive slope exceeding the second error value. Thus, embodiments of the invention are not limited to linear responses to different errors. This allows for greater flexibility and better control performance.

[0047] According to an embodiment of the invention, the attachment includes at least one of the following: one or more spoilers, which are particularly mounted along the longitudinal direction of the blade; and a flap, which is particularly mounted at the tip of the blade.

[0048] Possible add-ons may include:

[0049] 1) Spoilers, for example, have discrete settings, i.e., open or closed, one or more segments.

[0050] 2) Trailing edge flap, continuous (adjustable angle) during operation, for example, one or more segments.

[0051] Other types of attachments are possible. It should also be understood that attachments of different kinds or types can coexist at the rotor blades, and all or each of these attachments can be controlled in conjunction with the control of all other attachments, or in conjunction with or dependent on rotor blade pitch control. In particular, embodiments of the invention may also envision staggered control, which begins with the attachment having the least impact on aerodynamic properties, followed by control of attachments having a moderate impact on aerodynamic control or aerodynamic effects.

[0052] It should be understood that features disclosed, described, explained, or provided individually or in any combination for a method of controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade and at least one blade attachment are also applicable individually or in any combination to apparatus for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade and at least one blade attachment according to embodiments of the invention, and vice versa.

[0053] According to an embodiment of the present invention, an apparatus is provided for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade having a blade attachment and at least one blade attachment, the apparatus including a control module adapted to adjust the setting of the attachment to meet a control objective while temporarily maintaining the setting of the blade pitch angle.

[0054] In addition, a wind turbine is provided, comprising: at least one rotor blade on which an accessory is mounted; and a device according to the previous embodiment, which is coupled to a blade pitch adjustment system and an accessory adjustment system.

[0055] The foregoing and further aspects of the present invention will become apparent from the examples of embodiments described below, and will be explained with reference to these examples. Hereinafter, the invention will be described in more detail with reference to examples of embodiments, but the invention is not limited to these examples. Attached Figure Description

[0056] Embodiments of the invention will now be described with reference to the accompanying drawings. The invention is not limited to the illustrated or described embodiments.

[0057] Figure 1 An apparatus for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade having a blade attachment and at least one blade attachment according to an embodiment of the present invention is illustrated, the apparatus implementing a method for controlling a wind turbine according to an embodiment of the present invention.

[0058] Figure 2 An apparatus for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade having a blade attachment and at least one blade attachment according to an embodiment of the present invention is illustrated, the apparatus implementing a method for controlling a wind turbine according to an embodiment of the present invention.

[0059] Figure 3 and Figure 4 An example of 2D gain scheduling as employed according to an embodiment of the present invention is illustrated;

[0060] Figure 5 An apparatus for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade having a blade attachment and at least one blade attachment according to an embodiment of the present invention is illustrated, the apparatus implementing a method for controlling a wind turbine according to an embodiment of the present invention.

[0061] Figure 6 An apparatus for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade having a blade attachment and at least one blade attachment according to an embodiment of the present invention is illustrated, the apparatus implementing a method for controlling a wind turbine according to an embodiment of the present invention.

[0062] Figures 7 to 9The illustrations depict possible implementations for deriving error-related quantities based on errors utilized, for example, in embodiments of the invention, particularly in the first, second, and / or third functions. Detailed Implementation

[0063] According to embodiments of the present invention Figure 1 The apparatus 100 schematically illustrated for controlling a wind turbine by adjusting the blade pitch angle and at least one blade attachment includes a control module 103 adapted to adjust the settings of the attachment to meet control objectives while maintaining the blade pitch angle settings, and is therefore suitable for implementing the method according to an embodiment of the invention.

[0064] Thus, the setting of the attachment is adjusted by providing a reference attachment setting 105 to an actuator (not shown), which is configured to move the attachment (see, for example...). Figure 11 (It shows an attachment 1065) for adjusting the settings. Furthermore, the device 100 outputs a reference blade pitch angle 107. However, this reference rotor blade pitch angle 107 is maintained at least within a specific range of the speed error 109, as will be explained in detail below.

[0065] In the scheme illustrated in the figure, the control objective is to achieve and / or track a reference rotational speed of the bladed rotor. A rotational speed error 109 is calculated from this and input to device 100 as the difference between the reference rotational speed (e.g., the design speed of the wind turbine) and the actual rotational speed (e.g., a measured or estimated speed, possibly filtered). Primarily, the blade attachment can be adjusted using a reference attachment setting 105 while maintaining a constant rotor blade pitch angle for relatively small rotational speed errors 109. The speed attachment controller 110 determines the attachment setting 105 based on the rotational speed error 109.

[0066] However, the blade pitch angle can be adjusted based on the rotational speed error 109 and the add-on setting displacement 111, which is the difference between the reference add-on setting 105 and the nominal add-on setting 113. The blade pitch angle can only be adjusted if: the rotational speed error is greater than a threshold and / or the add-on setting displacement 111 is greater than a displacement threshold and / or the add-on setting or reference add-on setting 105 is closer to at least one add-on setting limit than at least one limit threshold (e.g., if the add-on setting is too close to the add-on setting limit, leaving insufficient adjustment capacity). This avoids unnecessary adjustments to the blade pitch angle.

[0067] exist Figure 1 The first function block 115 is specified, which calculates the related control quantity 117 of the attachment setting displacement based on the attachment setting displacement 111.

[0068] The add-on set displacement-related control quantity 117 is input to the speed-pitch controller 119, and the reference blade pitch angle 107 is adjusted or calculated based on the add-on set displacement-related control quantity 117.

[0069] exist Figure 1 The second function module 121 is specified, which calculates the speed error-related control quantity 123 based on the speed error 109. The reference rotor blade pitch angle 107 is calculated based on the speed error-related control quantity 123. Specifically, the additional setting allows both the displacement-related control quantity 117 and the speed error-related quantity 123 to be input to the speed-pitch controller 119, from which the reference pitch angle 107 is derived.

[0070] The first function module 115 is implemented by a first gain scheduler 125 acting on the add-on set displacement 111. The output of the gain scheduler 125 is multiplied by the add-on set displacement 111 using a multiplier element 120 to generate the add-on displacement-related control quantity 117.

[0071] Furthermore, a second control module 121 is implemented using a second gain scheduling 127 applied to the speed error 109. The output of the gain scheduling 127 is multiplied by the speed error 109 to generate a 'speed error-related control quantity' 123.

[0072] It should be understood that features or elements with similar structure and / or function in different embodiments are illustrated in different figures by reference numerals that differ only in the first digit. Descriptions of specific elements not described in detail with reference to a particular embodiment may be obtained from the description of the corresponding element in another figure or embodiment.

[0073] According to an embodiment of the present invention, a speed control scheme utilizing both an active blade attachment and a pitch actuator is proposed. Therefore, at least two blade actuation systems are used, working together to control the rotor speed. Consequently, at least two controllers are utilized:

[0074] • Speed ​​add-on controller (e.g., PID controller), which adjusts the blade add-on reference to control the rotational speed, and

[0075] • Speed-pitch controllers (e.g., PID controllers) adjust the pitch reference to control the combination of speed and blade attachment position, thereby obtaining gain schedules based on two quantities.

[0076] The control scheme illustrated in the figure allows the blade attachment to have the highest priority in controlling the rotational speed, while pitch actuation is reduced and primarily used to obtain the operating point in the desired region. Pitch actuation is mainly used to handle large speed fluctuations and change the operating point.

[0077] exist Figure 1and Figure 2 In this context, gain scheduling is used to prioritize which actuator has the control speed. Gain scheduling (e.g., 125, 127) can have values ​​between 0 and 1 and can be used to reduce pitch actuation while maintaining the speed at its setpoint using blade attachments.

[0078] Gain scheduling 127 ensures that the speed-pitch controller 119 will not act on small speed errors that can be managed by the speed add-on controller 110.

[0079] exist Figure 1 In this process, the speed error 109 is provided as an input to the speed attachment controller 110, which derives the reference attachment setting 105 accordingly.

[0080] The addend setting displacement 111 is applied to the first function 125. This first gain scheduling function 125 ensures that the speed-pitch controller 119 operates only on the addend displacement 111 whenever the speed addend controller is a given distance from its nominal addend setting 113. This feature ensures that the pitch angle will, on average, keep the addend at its nominal (desired) condition by (slowly) adapting to new operating points.

[0081] Figure 2 The device 200 shown in the figure and Figure 1 The device 100 illustrated in the figure is similar. However, the device 200 additionally includes a third function module 229. The third function module 229 calculates the additional setting-related control quantity 231 and provides it as input, along with the speed error 209, to the 2D gain scheduling 233. (See from...) Figure 2 It is understandable that the reference blade pitch angle 207 is based on the speed error 209 and the related control quantity 231 set by the auxiliary component.

[0082] If it can be seen, Figure 2 The second control module 235 is similar to Figure 1 The second function module 121, as illustrated, outputs a speed error-related control quantity 223, which is input to a speed-pitch controller 219 to derive a reference blade pitch angle 207. This reference blade pitch angle is also based on an additional displacement-related control quantity 217, as output by the first control module 215, which is similar to... Figure 1 The first control module 115 is shown in the diagram. Therefore, in Figure 2 In the figure, the speed error related quantity 223 is also derived from the remaining capacity of the attachment from its limit.

[0083] exist Figure 2In this configuration, gain adjustments 225 and 233 can vary between 0 and 1, and are used to reduce pitch actuation while maintaining the rotational speed at its setpoint using blade attachments. Figure 2 In this process, a 2D lookup table or 2D gain scheduling 233 is used to obtain the speed error-related control quantity 223. The scheduling variable can be a function of the speed error and the accessory reference. This function can present the accessory reference as a percentage of the accessory capacity availability. The accessory capacity is set by the minimum reference value and the maximum reference value.

[0084] exist Figure 2 In this implementation, the third function 229 is performed using a low-pass filter 230, a differential element 232, and a division element 234. Minimum add-on reference 204 and maximum add-on reference 206 are input to the differential element 232, and the output of the low-pass filter 230 is provided to one of the differential elements 232. The output of the differential element 232 is supplied to the division element 234. Amplification of the output of the division element 234 is performed using a gain element 236. Therefore, the resulting add-on setting related control quantity 231 is a function of the reference add-on setting 205 and the minimum add-on setting 204 and maximum add-on setting 206.

[0085] exist Figure 3 and Figure 4 Two examples of 2D gain scheduling 338 and 438 (Figures 343 and 443) are presented. The gain is indicated on the vertical axis 337 and 437, and the gain is plotted with respect to the add-on reference capacity 339 and 439 and the speed error 341 and 441. Figure 3 An example is illustrated where the gain is 0 for small speed errors and for add-on references far from their limits. Large speed errors or add-on references near their limits can cause the gain to increase and become one.

[0086] Figure 4 An example is illustrated where gain scheduling depends on the sign of the velocity error and whether the addend is closer to its minimum or maximum limit. A 2D gain scheduling lookup can also be configured to vary only in one of its two dimensions: a function of the velocity error or the addend reference, thus effectively becoming a 1D gain scheduling.

[0087] According to an embodiment, Figure 1 and 2 The apparatus illustrated herein can be used to provide an example where gain scheduling is used to prioritize which actuator has the control rotational speed (assuming the add-on operates in an on / off manner). This can be applied, for example, when the add-on is formed by several segments (e.g., 4 to 10 or 12) that can be opened or closed, or switched on and off (discontinuous control).

[0088] Given the number of segments N of the blade attachment, the maximum limit of the blade attachment reference can be limited as a percentage of the available segments (in %).

[0089] Rmax = (N – N_faulty) / N * 100,

[0090] Where N_faulty is the number of faulty segments. In this example, the lower reference limit remains constant when Rmin = 0%. Rmin can be compared with... Figure 2 In the equation, 204 is relevant and Rmax can be relevant to 206.

[0091] One or more active add-on devices and concepts can be used. One example is the use of segmented add-ons, where a set of elements is capable of independently inducing aerodynamic stall in local sections of the rotor blades. An active flap can be another add-on device.

[0092] The speed control concepts explained in this article have a wide range of applications, as speed control is a discipline within the broader field of wind turbine control. These may include, but are not limited to:

[0093] • Use active blade attachments for speed control during reduction operations. This reduces pitch activity. Consequently, it is possible to relax the speed tracking requirements for this type of operation.

[0094] • Use the active blade attachment for speed control during active idling. During active idling, it may be sufficient to control the speed within a range of RPMs (rather than a single setpoint value), and control can occur solely through the active blade attachment, thereby reducing wear and energy consumption for the pitch system, or using the pitch system only sparingly for partial savings / reductions.

[0095] • Speed ​​control using active blade attachments during resonance avoidance. Several speed zones exist where operation is undesirable, for example, where the tower frequency conflicts with the 1P or 3P rotation frequency. In these cases, active blade attachments can be applied to force operation outside these speed zones.

[0096] • Use active blade attachments for speed control during high-wind operations. This reduces pitch activity. It's possible that speed tracking requirements are relaxed for this type of operation, at least where speed support is reduced for high winds.

[0097] • Use active blade attachments for speed control during self-sustained operation. Speed ​​control via active blade attachments can be expected to reduce wear and energy consumption in the pitch system.

[0098] Several of the following advantages or technical features can be achieved: reduced costs due to reduced blade pitch bearing and (hydraulic or electric) pitch system loads caused by reduced pitch reference excitation via gain scheduling, which eliminates control errors that could be handled by add-ons. Alternatively, this allows for larger turbines with similar hardware for the pitch bearing and pitch system.

[0099] Power production performance can be maintained or improved because the add-on acting on the speed error can be used to maintain or improve speed regulation performance, resulting in less drop below nominal speed and / or less drop below nominal power. Control of the add-on according to embodiments of the invention can also be performed during startup depending on wind speed and power references.

[0100] Figure 5 and Figure 6 Further embodiments of control devices 500 and 600 according to an embodiment of the present invention are illustrated, wherein control modules 515, 521 use dead-time functions instead of gain scheduling, specifically a first dead-time function 526 and a second dead-time function 528. However, these first functions 515 and second functions 521 have the same characteristics as... Figure 1 The functions 115 and 121 shown in the figure have similar effects.

[0101] exist Figure 6 In this module, the third function 629 also includes a low-pass filter 630 and a differential element 632. However, the output of the differential element is provided to gain elements 614 and 616, which respectively provide limits within the positive range and the negative range of the dead-time function 628. Thus, the width of the dead-time element 628 can be set by the difference between the add-on reference and the minimum and maximum limits of the add-on, representing the remaining capability of the add-on to adjust the speed in each direction. Therefore, the output of the third function module 629 can be defined such that the error value at the positive error range of its dead-time 628 is not 0 and the error value at the output in its negative error range is not 0.

[0102] Alternatively or additionally, for example, the slope of the positive speed error can be adjusted in a different way than the slope of the dead zone module 628 in the negative speed error range. This achieves greater flexibility.

[0103] Figure 7 , Figure 8 and Figure 9 Different implementations of the first or second function modules 721, 821, 921 are illustrated, which can be utilized as first function modules and / or second function modules, for example, in any of the foregoing embodiments. Figure 7The scheduling or gain scheduling 725 of the first function module 721 shown in the figure is applied to the speed error 709, and the result is multiplied by the speed error 709 to generate a speed error related control signal 723.

[0104] exist Figure 8 In this process, the speed error 809 is applied to the gain scheduling 825 to generate a speed-related control signal 823.

[0105] exist Figure 9 In this process, the speed error 909 is applied to the dead zone element or function 928 to generate a speed-related control quantity 923.

[0106] Figure 10 A coordinate system is illustrated, with the horizontal axis 1050 indicating the error and the vertical axis 1052 indicating the output of the gain scheduling module or dead-time module, such as those used and illustrated in the above figures. Curve 1051 illustrates an example of dead-time, and curve 1053 illustrates an example of gain scheduling.

[0107] The dead zone curve 1051 includes a first linear segment 1051a with a positive slope up to a first error value 1055, a horizontal segment 1051b extending beyond the first error value up to a second error value 1057, and further includes a second linear segment 1051c extending beyond the second error value 1057.

[0108] The gain scheduling curve 1053 includes a first nonlinear segment 1053a up to a first error value 1055, a horizontal segment 1053b extending beyond the first error value 1055 up to a second error value 1057, and a second nonlinear segment 1053c extending beyond the second error value 1057. Beyond the first and second error values, the gain scheduling function 1053 may include linear segments.

[0109] Figure 11 A wind turbine 1060 is schematically illustrated, comprising a rotor 1061 on which a plurality of rotor blades 1063 are mounted, wherein at least one rotor blade has adjustable attachments 1065, such as a plurality of segments 1067 including spoilers. The wind turbine 1060 further includes a device 1000, which can be configured to... Figure 1 , Figure 2 , Figure 5 or Figure 6 The devices 100, 200, 500, or 600 are illustrated in the figure. Device 1000 controls the setting of the attachment 1065 and the rotor blade pitch angle by using a pitch system 1069, wherein a rotational speed 1062 (as measured by sensor 1064) (and other input values, for example) is received. The rotor 1061 is housed inside a nacelle 1071, which is mounted on top of the wind turbine tower 1073.

[0110] It should be noted that the term "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude multiple. Furthermore, elements described in different embodiments may be combined. It should also be noted that the reference numerals in the claims should not be construed as limiting the scope of the claims.

Claims

1. A method for controlling a wind turbine (1060) by adjusting the blade pitch angle of at least one wind turbine rotor blade (1063) having a blade attachment (1067) and at least one blade attachment, the method comprising: Adjust the settings of the attachment (1067) to meet the control objective, while temporarily maintaining the setting of the blade pitch angle; The control objective includes achieving and / or tracking a reference rotational speed of the rotor on which the blades are mounted. The setting of the attachment is adjusted based on the rotational speed error (109), which is the difference between the reference rotational speed and the actual rotational speed. The method includes: The speed error (109) is supplied to the speed attachment controller (110), which outputs a reference attachment setting (105). The reference attachment setting (105) and the nominal attachment setting (113) are supplied to the differential element (114) to calculate the attachment setting displacement (111), wherein the nominal attachment setting corresponds to the following settings: wherein the attachment has a setting regarding the effect of 50% on the aerodynamic properties of the blade or the total capacity of the airflow around the blade, and / or a setting for the expected normal operation of the wind turbine, the total disconnection state of the attachment, and / or an attachment setting point calculated based on the attachment utilization factor; The first function (115) is applied to the attachment setting displacement (111) to obtain the attachment setting displacement related control quantity (117). The second function (121) is applied at least to the speed error (109) to obtain the speed error related control quantity (123). The displacement-related control quantity (117) and the speed error-related control quantity (123) of the attachment are supplied to the speed-pitch controller (119), which outputs the reference blade pitch angle (107).

2. The method according to claim 1, further comprising: The blade pitch angle is adjusted based on the speed error (109) and the attachment setting displacement (111), wherein the attachment setting displacement is the difference between the reference attachment setting (105) and the nominal attachment setting (113). The blade pitch angle (107) is adjusted only in the following circumstances: The speed error (109) is greater than the speed error threshold, which depends on how close the attachment setting is to at least one attachment setting limit, and / or The attachment is set to a displacement (111) greater than a displacement threshold, and / or The add-on setting (105) is closer to at least one add-on setting limit than at least one limit threshold.

3. The method according to claim 2, wherein, The nominal attachment setting (113) corresponds to the following setting: the attachment can be adjusted from the setting along two different / opposite directions, the two directions affecting the blade wind interaction and / or The wind-driven force and / or the airflow around the blades have different / opposite aerodynamic effects.

4. The method according to any one of claims 1-3, further comprising: The third function (229), which includes at least one add-on setting limit (204, 206), is used to calculate at least one add-on setting related control quantity (231) based on the add-on setting (205). The second function (235) is used to calculate the 'speed error and accessory-related control quantity' (223) based on the speed error (209) and the accessory setting related control quantity (231). The adjustment of the blade pitch angle based on the speed error includes adjusting the blade pitch angle (107) based on the 'speed error and accessory related control quantity' (231).

5. The method according to any one of claims 1-3, further comprising: The third function (229) is applied to the reference add-on setting (205) to obtain the add-on setting related control quantity (231); The second function (235) is further applied to the accessory setting related control quantity (231) and the speed error (209) to obtain the speed error and accessory setting related control quantity (223). The attachment setting displacement related control quantity (217) and the 'speed error and attachment setting related control quantity' (223) are applied to the speed-pitch controller (219), which outputs a reference blade pitch angle (207).

6. The method according to any one of claims 1-3, wherein, The first function (115) and / or the second function (121) and / or the third function (229) includes at least one of the following: 1D or 2D gain scheduling functions (343, 443, 1053); Dead zone function (1051).

7. The method according to claim 6, wherein, The dead zone function (1051) includes a first linear segment (1051a) with a positive slope up to a first error value (1055), a horizontal segment (1051b) exceeding the first error value up to a second error value (1057), and a second linear segment (1051c) with a positive slope exceeding the second error value.

8. The method according to claim 6, wherein, The gain scheduling function (1053) includes a first nonlinear segment (1053a) with a positive slope and / or monotonically increasing up to a first error value, a horizontal segment (1053b) exceeding the first error value up to a second error value, and a second nonlinear segment (1053c) exceeding the second error value with a positive slope and / or monotonically increasing up to a second error value.

9. The method according to any one of claims 1-3, wherein, The attachment includes at least one of the following: One or more spoilers; Removable plate.

10. The method according to claim 4, wherein, The attachment has a limit boundary setting; once this boundary is exceeded, the setting cannot be increased or decreased.

11. The method according to claim 6, wherein, The dead zone function (1051) has an adjustable limit.

12. The method according to claim 9, wherein, One or more spoilers are installed along the longitudinal direction of the blade (1063).

13. The method according to claim 9, wherein, The flap is installed at the tip of the blade (1063) or at the trailing edge of the rotor blade.

14. An apparatus for controlling a wind turbine by adjusting the blade pitch angle of at least one wind turbine rotor blade (1063) having a blade attachment and at least one blade attachment, the apparatus comprising: A control module (103) is adapted to adjust the settings of the attachment (1065) to meet the control objective, while temporarily maintaining the setting of the blade pitch angle; The device is adapted to control or implement the method according to any one of claims 1-13.

15. A wind turbine (1060) comprising: At least one rotor blade (1063) is fitted with an accessory (1065). as well as The device according to claim 14 is connected to the blade pitch adjustment system (1069) and the accessory adjustment system.

Images