Methods for using site-specific wind conditions to determine when a tipping device should be installed on a rotor blade of a wind turbine

Abstract

A method for using site-specific data to determine whether a tipping device should be installed on a rotor blade of a wind turbine, wherein the method comprises the steps of: monitoring at least one wind condition at a wind turbine site using a sensor; determining an actual tipping threshold for a rotor blade of a wind turbine located at the wind turbine site based on the at least one wind condition; comparing the actual tipping threshold with a predetermined tipping threshold for the rotor blade; and determining whether a tipping device should be installed on the rotor blade based on the comparison between the actual tipping threshold and the predetermined tipping threshold.

Description

Field and purpose of the invention The present invention relates generally to wind turbines and in particular to a method for using site-specific wind conditions to determine when a tipping device should be installed on a rotor blade of a wind turbine. Background of the invention Wind power is considered one of the cleanest and most environmentally friendly energy sources currently available, and wind turbines have received increased attention in this regard. A modern wind turbine typically consists of a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. Using established wing principles, the rotor blades capture kinetic energy from the wind and convert it into rotational energy to turn a shaft that connects the rotor blades to a gearbox, or, if no gearbox is used, directly to the generator. The generator then converts the mechanical energy into electrical energy, which can be fed into a power grid. To ensure that wind power remains a viable energy source, efforts have been made to increase energy output by modifying the size and capacity of wind turbines. One such modification has been the insertion of a tipping device (such as a winglet) at the tip of each rotor blade. Essentially, winglets can be used to improve the overall efficiency and power output of a wind turbine. Winglets can be attached to rotor blades to reduce the overall diameter of the turbine and to lower the noise emitted by the blades. Furthermore, winglets can also increase the power-to-efficiency ratio of a wind turbine, thereby reducing the cost of the energy it generates. It is generally known that suction-side winglets are more efficient than pressure-side winglets. However, on wind turbines with rotors positioned upwind in front of the tower, the use of suction-side winglets can be very problematic. In particular, attaching a suction-side winglet to a rotor blade reduces the clearance between the blade tip and the tower. Such a reduction in the tower clearance can significantly increase the risk of one or more rotor blades striking the tower, which can be a very costly event requiring considerable downtime for repair and / or replacement of damaged components. A possible consequence of tower contact can also be catastrophic tower failure. Therefore, a method for using site-specific wind conditions to determine when a tip device, such as a suction-side winglet or a tip extension, can be fitted to a rotor blade to increase the overall power of the blade without significantly increasing the risk of tower contact would be welcome in engineering. Brief description of the invention Aspects and advantages of the invention are partly presented in the following description or may be apparent from the description or can be recognized through the practical implementation of the invention. In one aspect, the present invention describes a method for using site-specific data to determine whether a tipping device should be installed on a rotor blade of a wind turbine. The method essentially comprises monitoring at least one wind condition at a wind turbine site using a sensor, determining an actual peak deflection threshold for a rotor blade of a wind turbine located at the site based on the at least one wind condition, comparing the actual peak deflection threshold with a predetermined peak deflection threshold for the rotor blade, and determining whether a tipping device should be installed on the rotor blade based on the comparison between the actual peak deflection threshold and the predetermined peak deflection threshold. In another aspect, the present invention describes a method for using site-specific data to determine whether a suction-side winglet should be installed on a rotor blade of a wind turbine. The method can essentially include monitoring at least one wind condition at a wind turbine site using a sensor, determining an actual peak deflection threshold for a rotor blade of a wind turbine located at the site based on the at least one wind condition, comparing the actual peak deflection threshold with a predetermined peak deflection threshold for the rotor blade, and determining whether a suction-side winglet should be installed on the rotor blade based on the comparison between the actual peak deflection threshold and the predetermined peak deflection threshold. In another aspect, the present invention describes a method for using site-specific data to determine whether a suction-side winglet should be fitted to a rotor blade of a wind turbine.The procedure can essentially involve providing a rotor blade for a wind turbine with a predetermined peak deflection threshold based on a wind turbine classification, determining an actual peak deflection threshold for a rotor blade based on at least one wind condition present at a wind turbine site, comparing the actual peak deflection threshold with the predetermined peak deflection threshold for the rotor blade, and determining whether a peak deflection device should be fitted to the rotor blade based on the comparison between the actual peak deflection threshold and the predetermined peak deflection threshold. These and other features, aspects, and advantages of the present invention will be better understood by reference to the following description and the accompanying claims. The accompanying drawings, which are included in and form part of this patent specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Brief description of the drawings A complete and fundamental disclosure of the present invention, including its best embodiment, to the person skilled in the art, is described below in the patent specification with reference to the accompanying drawings, in which: Fig. 1 shows a perspective view of an embodiment of a wind turbine; Fig. 2 shows a flowchart of an embodiment of a method for using site-specific wind conditions to determine when a tipping device should be mounted on a rotor blade of a wind turbine; Fig. 3 shows a partial side view of an embodiment of a wind turbine, and in particular shows one of the rotor blades of the wind turbine in a non-deflected state and a deflected state; Fig. 4 shows an embodiment of the wind turbine shown in Fig. 3 with a suction-side winglet mounted on one of the rotor blades; and Fig.Figure 5 represents an embodiment of the wind turbine shown in Fig. 3 with a tip extension mounted on one of the rotor blades. Detailed description of the invention Detailed reference will now be made to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided within the context of an explanation of the invention, not a limitation of the invention. Indeed, it should be apparent to those skilled in the art that various modifications and changes can be made to the present invention without deviating from the scope of protection or the inventive concept. For example, features illustrated and described as part of one embodiment can be used in another embodiment to obtain yet another embodiment. Thus, the present invention is intended to cover such modifications and changes, insofar as they fall within the scope of protection of the appended claims and their equivalents. The present invention essentially relates to methods for using site-specific wind data to determine when a tipping device should be installed on a rotor blade. In particular, the disclosed methods use site-specific wind data to identify when the actual tip deflection experienced by a rotor blade deviates from the deflection for which the blade was designed. For example, the actual tip deflection experienced by a rotor blade during operation can often be significantly less than the maximum permissible deflection, thereby creating a positive difference or deflection margin between the actual deflection and the maximum additional deflection. By determining when such a deflection margin exists for a specific wind turbine, a tipping device, which typically leads to a reduction in the overall tower clearance (e.g.,in the case of a suction side winglet or tip extension) to which rotor blades are attached to improve its performance without significantly increasing the probability of tower contact. Fig. 1 shows a perspective view of an embodiment of a wind turbine 10. As shown, the wind turbine 10 comprises a tower 12 extending from a support surface 14, a nacelle 16 mounted on the tower 12, and a rotor 18 connected to the nacelle 16. The rotor 18 includes a rotatable hub 20 and at least one rotor blade 22 connected to and extending from the hub 20. As shown, the rotor 18 has three rotor blades 22. However, in an alternative embodiment, the rotor 18 can have more or fewer than three rotor blades 22. The rotor blades 22 can be arranged at intervals around the hub 20 to allow the rotating rotor 18 to convert kinetic energy from the wind into usable mechanical energy and subsequently into electrical energy. The wind turbine 10 can be arranged at a wind turbine site 24. According to the illustration, the wind turbine site 24 contains only one wind turbine 10. However, in other embodiments, any number of wind turbines 10 can be arranged at the wind turbine site 24. For example, the wind turbine site 24 can correspond to a wind turbine farm with multiple wind turbines 10. Furthermore, as shown in Fig. 1, the wind turbine 10 can also include a turbine control system or a turbine control unit 26 centralized in the cell 16. However, it should also be apparent that the turbine control unit 26 can be located anywhere on or in the wind turbine 10, at any point on the support surface 14, or generally at any location. The control unit 26 can essentially be configured to control the various operating modes (e.g., start-up or shutdown sequences) and / or the components of the wind turbine 10. For example, the control unit 26 can be configured to set an angle of attack or the blade pitch of each of the rotor blades 22 (i.e., the angle that determines a perspective of the rotor blades 22 with respect to the direction 26 of the wind) by setting an angular position of at least one of the rotor blades 22 with respect to the wind. It should be apparent that the plant control unit 26 can generally include any suitable processing unit, such as a computer or any other suitable computing unit. Thus, the plant control unit 26, in various embodiments, can include one or more processors and associated memory devices configured to perform a variety of computer-implemented functions. As used herein, the term "processor" refers not only to integrated circuits contained in a computer according to the relevant field, but also to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application-specific integrated circuit, and other programmable circuits. Additionally, the plant control unit 26 can include...The storage element(s) of the plant control system 26 essentially comprise one or more storage elements which include, but are not limited to, a computer-readable medium (e.g., working memory (RAM)), a computer-readable non-volatile medium (e.g., flash memory), a floppy disk, a compact disc read-only storage (CD-ROM), a magneto-optical disk (MOD), a digital versatile disk (DVD), and / or other suitable storage elements. Such storage devices may essentially be configured to store suitable computer-readable instructions which, when implemented by the processor(s), adapt the plant control system 26 to perform various functions, including, but not limited to, monitoring one or more wind conditions at the plant site 24 and determining the tip deflection of the rotor blades based on the wind conditions at the wind turbine site 24.Additionally, the controller 26 can also include various input / output channels for receiving input signals from sensors and / or other measuring devices and for sending control signals to the various components of the wind turbine 10. As further referenced in Fig. 1 shows, during the operation of the wind turbine 10, wind strikes the rotor blades 22 from the direction 28, causing the rotor 18 to rotate about an axis of rotation 32. While the rotor blades 22 are rotating and subject to centrifugal forces, they can also be subjected to various forces and bending moments. Thus, the rotor blades 22 can deflect from a neutral or undisplaced position to a deflected or loaded position, thereby reducing the distance or tower gap 34 between each rotor blade 22 and the tower 12. To prevent the probability of tower contact, rotor blades 22 are typically designed with sufficient stiffness so that the maximum deflection of each blade is less than a predetermined deflection threshold. For example, according to the international standard IEC 64100 (developed and published by the International Electrotechnical Commission), the maximum tip deflection of a rotor blade 22 must not exceed 70% of the static tower clearance (i.e., the tower clearance 34 defined between the rotor blades 22 and the tower 12 when the wind turbine 10 is not operating). Thus, rotor blades installed in wind turbines 10 operating according to this standard must be designed so that, even under extreme wind conditions, the maximum tip deflection of each blade 22 does not exceed the deflection threshold.This is often achieved by designing the rotor blades 22 based on a specific wind turbine classification. In particular, under IEC-64100, a wind turbine 10 can be assigned to one of three classifications based on the expected operating conditions of the wind turbine 10, which include, but are not limited to, the annual average wind speed and the wind speeds of any extreme wind gusts that may occur over a specific period (e.g., 50 years).For example, a Class 1 wind turbine may be designed to operate at average annual wind speeds of 10 m / s and may be adapted to withstand an extreme 50-year gust of 70 m / s, whereas a Class 3 wind turbine may be designed to operate at average annual wind speeds of 7.5 m / s and may be adapted to withstand an extreme 50-year gust of 52.5 m / s. Consequently, due to the difference in wind conditions, a rotor blade 22 designed for a Class 1 wind turbine may be stiffer than a rotor blade 22 designed for a Class 3 wind turbine in order to maintain the maximum tip deflection for the rotor blade below 70% of the static tower space as required by the International Standard. Figure 2 shows an embodiment of a method 100 for using site-specific wind data to determine whether a tipper should be installed on a rotor blade 22 of a wind turbine. According to the illustration, the method 100 includes monitoring at least one wind condition at a wind turbine site 102 using a sensor, determining an actual peak deflection threshold for a rotor blade of a wind turbine located at the wind turbine site based on the at least one wind condition 104, comparing the actual peak deflection threshold with a predetermined peak deflection threshold for the rotor blade 106, and determining whether a tipper should be installed on the rotor blade based on the comparison between the actual peak deflection threshold and the predetermined peak deflection threshold 108. In particular, the inventors of the present invention have discovered that rotor blades 22 are often designed to withstand higher wind conditions than those actually present at the site 24 where the wind turbine 10 is installed. Consequently, the actual deflection experienced by the rotor blades 22 during operation is often significantly less than the deflection for which the rotor blades 22 were designed, thus generating a positive difference or deflection margin between the actual deflection and the maximum permissible deflection. By determining when such a deflection margin exists for a specific wind turbine 10, a tipping device can be mounted on a rotor blade 22 to improve its overall performance without increasing the probability of the blade 22 contacting the wind turbine tower 12. In 102, at least one wind condition at location 24 of a wind turbine 10 can be monitored using a sensor. Essentially, the wind conditions at a wind turbine location 24 can be monitored using any suitable wind data that can be acquired at location 24 using any suitable sensors and / or measuring devices known in the field. For example, in various embodiments, wind speed measurements can be taken at the wind turbine location 24 to enable the monitoring of different wind conditions. In such embodiments, a wind speed sensor 148 (three to five), such as an anemometer or another suitable measuring device, can be arranged at the wind turbine location 24, for example, by being attached to a section of the wind turbine 10 (e.g.,the wind speed sensor 148 is attached to the nacelle 16) or by being arranged at any other suitable location on the wind turbine site 24 to enable wind speed measurements. In one embodiment, the wind speed sensor 148 can also be coupled to the turbine controller 26 (Fig. 1) via a transmission connection (e.g., a wired or wireless connection) to allow the transmission of wind speed measurements to the controller 26 for subsequent storage and / or analysis. However, in other embodiments, the wind speed sensor 148 can be coupled to any other suitable processing unit capable of recording and / or analyzing the wind speed measurements. The wind speed measurements provided by the wind speed sensor 148 can be used to calculate the actual and / or predicted wind conditions for the wind turbine site 24. For example, an average wind speed and / or a wind speed distribution (e.g., the distribution or profile of the wind speed over a longer period of time) at the wind turbine site 24 can be calculated using the wind speed measurements. In particular, wind gusts (e.g., short-term changes in wind speed) and / or turbulence intensity (i.e., the ratio of the standard deviation of the wind speed to the mean wind speed over a specific period of time) at the wind turbine site 24 can also be determined by monitoring changes in wind speed. In 104, an actual peak deflection threshold value for a rotor blade 22 of a wind turbine 10 located at the wind turbine site 24 can be determined based on monitored wind conditions. As used herein, the term “actual peak deflection value” refers to a deflection limit value that corresponds to the maximum amount of peak deflection that can actually occur on a rotor blade 22 based on the wind conditions present at a specific wind turbine site 24. For example, Fig. 3 shows a partial side view of an embodiment of a wind turbine 10, which in particular shows a rotor blade 22 of the wind turbine 10 in a non-deflected state and in a deflected state (represented by a dashed line 122).As shown, when the rotor blade 22 is in a non-displaced state, a maximum tower clearance 140 is defined between the rotor blade 22 and the tower 12. However, when the rotor blade 22 is exposed to the maximum wind conditions for the wind turbine site, the tip 142 of the deflected rotor blade 122 is positioned at a maximum deflection position, corresponding to the actual tip deflection threshold (indicated by the dashed line 144). Thus, even under the most extreme wind conditions for the wind turbine site 24, a minimum tower clearance 146 is maintained between the actual tip deflection threshold 144 and the tower 12. In various embodiments, the actual peak deflection threshold 144 for a rotor blade 22 can be determined by analyzing the monitored wind conditions at the wind turbine site 24. In particular, by monitoring the site-specific wind conditions, the maximum peak deflection for a rotor blade 22 can be calculated based on the actual and / or assumed load present and / or potentially occurring on the blade 22 as a result of the wind conditions. However, those skilled in the art will recognize that various other operating conditions and / or parameters (e.g., hub height, blade design, and the like) can also be taken into account when determining the actual peak deflection threshold 144 of a rotor blade 22. In various embodiments, the wind speed measurements provided by the wind speed sensor 148 can enable the calculation and / or prediction of the maximum wind conditions for a specific wind turbine site 24. In particular, as is generally known, the maximum wind speed and / or the maximum wind gust occurring at a wind turbine site 24 can be directly measured (for example, using the wind speed sensor 148) and calculated and / or predicted using various observed wind conditions at the wind turbine site 24, including, but not limited to, the average wind speed and / or the wind speed distribution.For example, in various embodiments, the maximum wind speed and / or the maximum gust for a wind turbine site 24 can be calculated as a function of the average wind speed, for example by multiplying the average wind speed by a predetermined factor and / or percentage. In another embodiment, the maximum wind speed and / or a maximum gust for a wind turbine site 24 can be calculated based on a probability analysis, for example by analyzing the probability of a specific wind speed and / or gust occurring based on the average wind speed and / or the wind speed distribution at the site 24.It should be apparent that in alternative embodiments the maximum wind conditions for a wind turbine site 24 can be determined using other suitable wind conditions and / or calculation methods known in the field. Regardless, once the maximum wind conditions for a wind turbine site 24 have been determined, the maximum load that can occur on each rotor blade 22 due to such extreme wind conditions can be calculated, which can then be used to determine the maximum tip deflection for each blade 22. It should be apparent that the development of equations, models, transfer functions, and the like for correlating the maximum wind conditions of a wind turbine site 24 with the maximum deflection of a rotor blade 22 lies within the knowledge of a person skilled in the art and therefore need not be described here. Additionally, it should be apparent that in various embodiments, the maximum peak deflection and thus the actual peak deflection threshold value 144 is automatically determined using the turbine control 26 and / or any other suitable processing unit (such as a separate computer or computer device located at or away from the wind turbine site 24). For example, as indicated above, the wind speed sensor 148 can be coupled to the turbine control 26 and / or another processing unit via a transmission device to enable the transmission of wind speed measurements to the control 26 and / or another processing unit. In such an embodiment, the control 26 and / or another processing unit can be equipped with suitable equations, models, transfer functions, and the like (e.g.,stored as computer-readable instructions on the memory elements of the control / processing unit) which, when implemented, configure the control 26 and / or other processing unit to correlate the wind speed measurements with the actual peak deflection threshold 144. Returning to Fig. 2, the actual peak deflection threshold 144 determined above can be compared with a predetermined peak deflection threshold for the wind turbine 10 in Figure 106. As used herein, the term “predetermined peak deflection threshold” refers to a deflection limit that corresponds to the maximum permissible peak deflection that can be assumed based on the rotor blade design without significantly increasing the risk of tower contact. For example, as described above, a wind turbine 10 may often be assigned to one of three wind turbine classifications according to international standards, the rotor blades 22 of such a turbine being designed to maintain a blade deflection below a predetermined threshold for the specific wind conditions designed for the assigned classification.In such cases, a predetermined peak deflection threshold can be chosen to essentially correspond to the predetermined threshold defined by these standards. For example, as shown in Fig. 3, in one embodiment the predetermined peak deflection threshold (represented by the dashed line 150) can be defined as 70% of the static clearance for the wind turbine 10 according to the international standard IEC 64100. However, it should be apparent that in alternative embodiments the predetermined peak deflection threshold 150 can correspond to any other suitable design standard that can be used to define permissible rotor blade deflections and / or tower clearances. With further reference to Fig. 2, it can be determined in 108 whether a tipping device is to be installed on one or more of the rotor blades 22 of a wind turbine 10 based on a comparison of the actual peak deflection threshold value 144 and the predetermined peak deflection threshold value 150. In particular, in various embodiments, the decision as to whether a tipping device should be installed on the rotor blades 22 can be determined based on whether there is a deflection range between the actual peak deflection threshold value 144 and the predetermined peak deflection threshold value 150. For example, as shown in Fig.3. Because the rotor blades 22 of the wind turbine 10 are designed to withstand higher wind conditions than those actually present at the wind turbine site 24, the actual peak deflection threshold 144 is located further away from the tower 12 than the predetermined peak deflection threshold 150. Consequently, there is a difference or deflection margin 152 between the actual peak deflection threshold 144 and the predetermined peak deflection threshold 150, which corresponds to an additional distance over which the rotor blades 22 can deflect before exceeding the predetermined peak deflection threshold 152.Thus, according to aspects of the present invention, a tipping device designed to improve the overall behavior of the wind turbine 10 can be attached to one or more of the rotor blades 22 in order to take advantage of the deflection range 152 without increasing the probability of tower contact. For example, in various embodiments, a suction-side winglet can be attached to one or more of the rotor blades 22 of a wind turbine 10 if a deflection range 152 is found to exist. In particular, Fig. 4 shows a partial side view of an embodiment of the wind turbine shown in Fig. 3 with a suction-side winglet 154 attached to one of its rotor blades 22, and in particular shows the rotor blade 22 in a non-deflected state and a deflected state (shown by the dashed line 122). As shown, the winglet 154 extends substantially towards the tower 12 over a distance or height 156 (measured from a longitudinal or pitch axis 30 (Fig. 1) of the rotor blade to the winglet tip 158) that is equal to or less than the distance defined by the deflection range 152.Thus, when the rotor blade 22 is subjected to the maximum wind conditions at the wind turbine site 24, the maximum tip deflection of the deflected rotor blade 122 can be kept at a level equal to or less than the predetermined tip deflection threshold 150. This allows the numerous advantages of a suction-side winglet 154 (e.g., an increase in the power coefficient and a reduction in drag and noise) to be achieved without significantly increasing the probability of tower contact. It should be apparent that in alternative embodiments, any other suitable tip extension can be attached to one or more of the rotor blades 22 of a wind turbine 10 in order to take advantage of the available deflection range 152. Fig. 5 shows a partial side view of an embodiment of the wind turbine shown in Fig. 3 with a tip extension 160 attached to its rotor blades 22, and in particular shows the rotor blade 22 in a non-deflected state and in a deflected state (shown by the dashed line 122). As is generally known, attaching a tip extension 160 can increase the effective length of the rotor blade and thereby improve the blade's ability to capture energy from the wind. However, the additional length also leads to an increased load on the rotor blade 22 and thus increases the deflection of the rotor blade.Thus, in various embodiments, the length 162 of the tip extension 160 (measured from an original tip point 164 of the rotor blade 22) must be selected such that the total increase in blade deflection is equal to or less than the distance defined by the deflection tolerance 152. Therefore, when the rotor blade 22 is exposed to the maximum wind conditions at the wind turbine site 24, the maximum tip deflection of the rotor blade 22 can be kept at a level equal to or less than the predetermined tip deflection threshold 150. Thus, the various advantages of attaching a tip extension 160 to a rotor blade 22 (e.g., an increase in energy production) can be achieved without significantly increasing the probability of tower contact. It should be apparent that the tip devices 154, 160 described herein can be mounted on the rotor blades 22 of a wind turbine 10 using any suitable mounting devices and / or methods known in the field. For example, in some embodiments, an outer section of the rotor blade 22, including the blade tip, can be removed and replaced by the tip device 154, 160. In another embodiment, the tip device 154, 164 can be mounted on and / or above the existing blade tip of the rotor blade 22. It should also be apparent that in some embodiments, the comparison between the actual peak deflection threshold 144 and the predetermined peak deflection threshold 150, and the determination of whether a peak deflection device 154, 160 should be installed, can be performed automatically using the turbine control 26 and / or any other suitable processing unit (such as a separate computer or computer system) located at and / or remotely from the wind turbine site 24. For example, the control 26 and / or the other processing unit can be equipped with suitable models, decision logic, and the like (e.g.,stored as computer-readable instructions on the memory elements of the control / processing unit) which, when implemented, configure the control 26 and / or the other processing unit to compare the actual peak deflection threshold 144 with the predetermined peak deflection threshold 150 and to determine whether a peak device 154, 160 should be installed on one or more of the rotor blades 22 of a wind turbine 10. Additionally, it should be apparent that in some embodiments the present invention is also directed towards a method for utilizing site-specific data to determine whether a suction-side winglet 152 is to be installed on a rotor blade 22 of a wind turbine 10. For example, the method can involve observation with a sensor (e.g.,a wind speed sensor 148) at least one wind condition at the wind turbine site 24, the determination of an actual peak deflection threshold value 144 for the rotor blade 22 of a wind turbine 10 located at the site 24, based on the at least one wind condition, the comparison of the actual peak deflection threshold value 144 with a predetermined peak deflection threshold value 150 for the rotor blade 22 and the determination of whether the suction side winglet 154 is to be installed on the rotor blade 22 based on the comparison between the actual peak deflection threshold value 144 and the predetermined peak deflection threshold value 155. Furthermore, in further embodiments, the present invention also relates to a method for using site-specific methods to determine whether a tipping device should be installed on a rotor blade of a wind turbine, wherein the method includes providing a rotor blade 22 for a wind turbine 10 with a predetermined tip deflection threshold value 150 based on a wind turbine classification for the wind turbine (e.g., the classification assigned by the international standard IEC 64100), determining an actual tip deflection threshold value 144 for the rotor blade 22 based on at least one wind condition present at the wind turbine site 24, comparing the actual tip deflection threshold value 144 with the predetermined tip deflection threshold value 150, and determining whether a tipping device (e.g.,a suction side winglet or a tip extension 160) is to be attached to the rotor blade 22 based on the comparison between the actual tip deflection threshold 144 and the predetermined tip deflection threshold 150. This description uses examples to disclose the invention, including its best embodiment, and to enable anyone skilled in the art to put the invention into practice, including the manufacture and use of all elements and systems and the execution of all processes involved. The patentable scope of the invention is defined by the claims and may include further examples that are obvious to a person skilled in the art. Such further examples shall be included in the scope of the invention if they have structural elements that do not differ from the wording of the claims or if they contain equivalent structural elements with insignificant modifications compared to the wording of the claims. A method for using site-specific data to determine whether a tipping device should be installed on a wind turbine rotor blade is disclosed. The method essentially involves monitoring at least one wind condition at a wind turbine site using a sensor, determining an actual peak deflection threshold for a rotor blade of a wind turbine located at that site based on the at least one wind condition, comparing the actual peak deflection threshold with a predetermined peak deflection threshold for the rotor blade, and determining whether a tipping device should be installed on the rotor blade based on the comparison between the actual peak deflection threshold and the predetermined peak deflection threshold.

Claims

A method for using site-specific data to determine whether a tipping device should be installed on a rotor blade of a wind turbine, wherein the method comprises the steps of: monitoring at least one wind condition at a wind turbine site using a sensor; determining an actual tipping threshold for a rotor blade of a wind turbine located at the wind turbine site based on the at least one wind condition; comparing the actual tipping threshold with a predetermined tipping threshold for the rotor blade; and determining whether a tipping device should be installed on the rotor blade based on the comparison between the actual tipping threshold and the predetermined tipping threshold. Method according to claim 1, wherein the monitoring by means of a sensor of at least one wind condition at a wind turbine site comprises the step of measuring a wind speed by means of a wind speed sensor at the wind turbine site. The method according to claim 1, further comprising the step of analyzing the at least one wind condition to determine a maximum wind condition for the wind turbine site. Method according to claim 3, wherein the determination of an actual peak deflection threshold value for a rotor blade of a wind turbine located at the wind turbine site on the basis of the at least one wind condition comprises the step of determining the actual peak deflection threshold value on the basis of the maximum wind condition at the wind turbine site. Method according to claim 1, wherein the determination of an actual peak deflection threshold value for a rotor blade of a wind turbine located at the wind turbine site on the basis of the at least one wind condition comprises the step of determining the actual peak deflection threshold value by means of a processing unit on the basis of signals received from the sensor. The method of claim 1, wherein the comparison of the actual peak deflection threshold with a predetermined peak deflection threshold for the rotor blade comprises the step of comparing the actual peak deflection threshold with the predetermined peak deflection threshold to determine whether there is a deflection margin between the actual peak deflection threshold and the predetermined peak deflection threshold. Method according to claim 6, wherein the determination of whether a tip device should be mounted on the rotor blade based on the comparison between the actual tip deflection threshold and the predetermined tip deflection threshold comprises the step of determining whether the tip device should be mounted based on the existence of a deflection margin. Method according to claim 7, further comprising the step of attaching a suction side winglet to the rotor blade based on the deflection range. Method according to claim 8, wherein the height of the suction side winglet is equal to or less than the deflection range. Method according to claim 7, further comprising the step of attaching a tip extension to the rotor blade based on the deflection range. Method according to claim 1, wherein the predetermined blade deflection threshold is approximately 70% of a static tower space of the wind turbine. A method for using site-specific data to determine whether a suction-side winglet should be fitted to a rotor blade of a wind turbine, comprising the steps of: monitoring at least one wind condition at a wind turbine site using a sensor; determining an actual peak deflection threshold for a rotor blade of a wind turbine located at the wind turbine site based on the at least one wind condition; comparing the actual peak deflection threshold with a predetermined peak deflection threshold for the rotor blade; and determining whether a suction-side winglet should be fitted to the rotor blade based on the comparison between the actual peak deflection threshold and the predetermined peak deflection threshold. Method according to claim 12, wherein the monitoring by means of a sensor of at least one wind condition at a wind turbine site comprises the step of measuring a wind speed by means of a wind speed sensor at the wind turbine site. The method according to claim 12, further comprising the step of analyzing the at least one wind condition to determine a maximum wind condition for the wind turbine site. Method according to claim 14, wherein the determination of an actual peak deflection threshold value for a rotor blade of a wind turbine located at the wind turbine site on the basis of the at least one wind condition comprises the step of determining the actual peak deflection threshold value on the basis of the maximum wind condition at the wind turbine site. Method according to claim 12, wherein the determination of an actual peak deflection threshold value for a rotor blade of a wind turbine located at the wind turbine site on the basis of the at least one wind condition comprises the step of determining the actual peak deflection threshold value by means of a processing unit on the basis of signals received from the sensor. The method of claim 12, wherein the comparison of the actual peak deflection threshold with a predetermined peak deflection threshold for the rotor blade comprises the step of comparing the actual peak deflection threshold with the predetermined peak deflection threshold to determine whether there is a deflection margin between the actual peak deflection threshold and the predetermined peak deflection threshold. Method according to claim 17, wherein the determination of whether a suction-side winglet should be fitted to the rotor blade based on the comparison between the actual peak deflection threshold and the predetermined peak deflection threshold comprises the step of determining whether the suction-side winglet should be fitted based on the existence of the deflection margin. Method according to claim 18, further comprising the step of attaching the suction side winglet to the rotor blade based on the deflection range. A method for using site-specific data to determine whether a tipping device should be fitted to a rotor blade of a wind turbine, comprising the steps of: providing a rotor blade for a wind turbine with a predetermined tipping threshold value based on a wind turbine classification; determining an actual tipping threshold value for the rotor blade based on at least one wind condition present at a wind turbine site; comparing the actual tipping threshold value with the predetermined tipping threshold value for the rotor blade; and determining whether a tipping device should be fitted to the rotor blade based on the comparison between the actual tipping threshold value and the predetermined tipping threshold value.

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