System and method for preventing pitch bearing failure in a wind turbine using a pitch motor signal

Abstract

A method for preventing pitch bearing failures in a pitch system of a wind turbine includes monitoring, via at least one sensor, one or more electrical signals from a pitch motor of a pitch drive mechanism of the pitch system, the pitch motor driving a pitch bearing of the pitch system. The method also includes analyzing, via a controller, the one or more electrical signals from the pitch motor to remove noise and amplify outliers. Furthermore, the method includes estimating bearing friction of the pitch bearing using the analyzed one or more electrical signals from the pitch motor. Accordingly, the method includes implementing a control action, via the controller, when the estimated bearing friction of the pitch bearing indicates an abnormality in the pitch bearing.

Description

Technical Field

[0001] The present disclosure relates generally to wind turbines, and more particularly to systems and methods for detecting pitch bearing anomalies in a wind turbine using pitch motor signals. Background Art

[0002] Wind power is considered one of the cleanest and most environmentally friendly energy sources currently available, and wind turbines have garnered increasing attention in this regard. A modern wind turbine typically consists of a tower, a generator, a gearbox, a nacelle, and a rotor comprising one or more rotor blades. The rotor blades capture kinetic energy from the wind using the known airfoil principle and transfer this energy through rotational energy to rotate a shaft, which connects the rotor blades to the gearbox or, if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy into electrical energy that can be distributed to the utility grid.

[0003] During operation, the direction of the wind powering a wind turbine can change. Consequently, the wind turbine can adjust its nacelle, for example by yaw adjustment about the longitudinal axis of the tower, to maintain alignment with the wind. Additionally, the wind turbine can adjust the pitch angle of one or more rotor blades via a pitch drive mechanism configured with a pitch bearing to change the blade's angle relative to the wind.

[0004] A typical pitch drive mechanism includes a pitch drive motor, a pitch drive gearbox, and a pitch drive pinion. In such a configuration, the pitch drive motor is coupled to the pitch drive gearbox such that the pitch drive motor applies mechanical force to the pitch drive gearbox. Similarly, the pitch drive gearbox can be coupled to the pitch drive pinion for rotation therewith. The pitch drive pinion, in turn, can be rotationally engaged with a pitch bearing coupled between the hub and the corresponding rotor blade, such that rotation of the pitch drive pinion causes rotation of the pitch bearing. Thus, in such an embodiment, rotation of the pitch drive motor drives the pitch drive gearbox and the pitch drive pinion, thereby rotating the pitch bearing and the rotor blade about the pitch axis.

[0005] Because pitch bearings allow the rotor blades to move, failure of one of these bearings requires a turbine downtime event, reducing annual energy production. Pitch bearing failures can occur for a variety of reasons, including loads due to turbulence, shear, thrust, pitch activity (ball bunching, pitch travel, number of pitch cycles, etc.), bearing design, and / or lubrication. Furthermore, replacement of a pitch bearing can be very costly due to the large crane required in the event of a failure.

[0006] Thus, the present disclosure is directed to systems and methods for detecting pitch bearing anomalies in a wind turbine using signals from a pitch motor in order to avoid failure events. Summary of the Invention

[0007] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0008] In one aspect, the present disclosure relates to a method for preventing failure of a pitch bearing of a pitch system of a wind turbine. The method includes monitoring, via at least one sensor, one or more electrical signals of a pitch motor of a pitch drive mechanism of the pitch system, the pitch motor driving a pitch bearing of the pitch system. The method also includes analyzing, via a controller, the one or more electrical signals of the pitch motor to remove noise and amplify outliers. Furthermore, the method includes estimating bearing friction of the pitch bearing using the analyzed one or more electrical signals of the pitch motor. Accordingly, the method includes implementing a control action, via the controller, when the estimated bearing friction of the pitch bearing indicates an abnormality in the pitch bearing.

[0009] In one embodiment, the electrical signal(s) may include, for example, current, voltage, power, and / or torque. In another embodiment, the filter(s) may include a low-pass filter, a high-pass filter, a band-pass filter, or a combination thereof.

[0010] Thus, in one embodiment, analyzing the electrical signal(s) of the pitch motor to remove noise and amplify outliers may include filtering the electrical signal(s) of the pitch motor over a predetermined time period. For example, in one embodiment, filtering the electrical signal(s) of the pitch motor over a predetermined time period may include determining an average drift in the electrical signal(s) of the pitch motor over a predetermined time period, and removing the average drift from the electrical signal(s) of the pitch motor over a predetermined time period to reduce noise in one or more operational signals due to aerodynamic torsional torque on the rotor blades.

[0011] In another embodiment, filtering the electrical signals (of the plurality of) of the pitch motor over a predetermined time period may include removing noise due to the pitch acceleration torque by detecting a component of the motor torque that is 90 degrees ahead of the pitch rate in phase and removing that component from one or more electrical signals; removing noise due to the aerodynamic steady-state torsional torque by detecting an average drift in the motor torque and removing that average drift from one or more electrical signals; and normalizing a measure of friction using the pitch stroke and bearing load.

[0012] In another embodiment, estimating bearing friction of a pitch bearing using one or more analyzed electrical signals of a pitch motor may include generating a predictive computer model of the pitch bearing via a controller using the electrical signal(s) of the pitch motor and one or more operational signals of the pitch system. For example, in one embodiment, the operational signal(s) of the pitch system may include temperature of the pitch drive mechanism, ball bearing friction, cage stress, operating hours, thrust, brake activation, or pitch activity. More specifically, the pitch activity may include pitch motor energy per degree of pitch travel, pitch amount, pitch angle, or any other suitable pitch activity.

[0013] In another embodiment, the electrical signal(s) of the pitch motor include current. In such an embodiment, analyzing the electrical signal(s) of the pitch motor to remove noise and amplify outliers may include modifying the current using at least one of a root mean square (RMS) value, a standard deviation (SD) value, or a power value of the pitch motor to obtain a modified current value, and generating a heat map of the pitch bearing according to wind speed and time over a predetermined time period using the modified current value.

[0014] In several embodiments, estimating bearing friction of the pitch bearing using the analyzed one or more electrical signals of the pitch motor may include determining frictional power losses of the pitch bearing from a thermal map. In another embodiment, the method may include generating a thermal map of the pitch bearing using a digital twin model.

[0015] Thus, in certain embodiments, implementing a control action when the estimated bearing friction of the pitch bearing indicates an anomaly in the pitch bearing may include implementing a control action when a frictional power loss of the pitch bearing exceeds a predetermined threshold.

[0016] On the other hand, the present disclosure relates to a system for preventing failure of a pitch bearing of a pitch system of a wind turbine. The system includes at least one sensor configured to monitor one or more electrical signals of a pitch motor of a pitch drive mechanism of the pitch system, which pitch motor drives the pitch bearing of the pitch system. The system also includes a controller communicatively coupled to the (multiple) sensors. The controller includes at least one processor configured to perform a plurality of operations, including but not limited to analyzing one or more electrical signals of the pitch motor to remove noise and amplify outliers, estimating bearing friction of the pitch bearing using the analyzed one or more electrical signals of the pitch motor, and implementing a control action when the estimated bearing friction of the pitch bearing indicates an anomaly in the pitch bearing. It should also be understood that the system may further include any of the additional features and / or steps as described herein.

[0017] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A full and enabling disclosure of the invention, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification which proceeds with reference to the accompanying drawings in which:

[0019] Figure 1 shows a perspective view of a wind turbine according to one embodiment of the present disclosure;

[0020] Figure 2 shows a perspective view of the interior of a nacelle of a wind turbine according to one embodiment of the present disclosure;

[0021] Figure 3 A schematic diagram illustrating one embodiment of suitable components that may be included in a wind turbine controller according to the present disclosure;

[0022] Figure 4 A schematic diagram illustrating an embodiment of a pitch system for a wind turbine according to the present disclosure is shown;

[0023] Figure 5 A flow chart illustrating one embodiment of a method for preventing pitch bearing failure of a pitch system of a wind turbine according to the present disclosure;

[0024] Figure 6 A schematic diagram illustrating one embodiment of a system for preventing pitch bearing failure of a pitch system of a wind turbine according to the present disclosure is shown;

[0025] Figure 7 A schematic diagram illustrating another embodiment of a system for preventing pitch bearing failure of a pitch system of a wind turbine according to the present disclosure; and

[0026] Figures 8A-8C An example heat map according to the present disclosure is shown, specifically showing a damaged pitch bearing compared to two other healthy pitch bearings of the same wind turbine. DETAILED DESCRIPTION

[0027] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of illustration, not limitation, of the present invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as part of one embodiment may be used in conjunction with another embodiment to produce yet another embodiment. Therefore, it is intended that the present invention covers such modifications and variations within the scope of the appended claims and their equivalents.

[0028] In general, the present disclosure relates to systems and methods for detecting pitch bearing anomalies in wind turbines using signals from pitch motors to avoid failure events. As is well known, pitch motors move wind turbine rotor blades. Therefore, signals from such motors (e.g., current, voltage, power, air gap torque, temperature, pitch travel, etc.) provide valuable insights and can be used in a variety of ways according to the present disclosure. For example, in one embodiment, pitch motor signals can be used to estimate bearing friction and detect various bearing and pitch motor failure modes caused by, for example, lack of lubrication, grease leakage, seal rupture, cage overlap, cage protrusion and looseness, ball bunching, raceway degradation and truncation, ball wear / crack, pitch motor degradation, etc. In addition, the systems and methods of the present disclosure can reduce noise in such data by averaging and emphasizing outliers to develop time-varying covariates, which can guide inspections, life-extending mitigation measures (e.g., debris removal, greasing, resealing), prediction of when bearings are likely to fail, and replacement schedules for maximum crane productivity.

[0029] In another embodiment, the pitch signal can be used to estimate aerodynamic torsional torque by measuring pitch motor counter-torque, which can be used to detect blade misalignment, blade wear, icing, and wind estimation. Furthermore, the pitch signal can be used to detect torsional resonance instabilities in the blades and pitch motor control instabilities, as well as to estimate blade torsional frequency. Furthermore, by collecting the pitch signal, pitch activity can also be monitored and flagged if excessive, as increased pitch activity may be caused by closed-loop instability.

[0030] In yet other embodiments, the pitch signal can be normalized for the pitch stroke and used to estimate net bearing tribological parameters such as friction coefficient, slip at maximum friction, power loss during friction hysteresis, etc., which can help further differentiate and pinpoint the fault mode. In addition, the pitch signal can be used to estimate the contribution to the pitch torque due to gravity and blade bending, and thus used to estimate blade flapping stiffness and blade deflection and possible shear.

[0031] Now referring to the accompanying drawings, Figure 1A perspective view of one embodiment of a wind turbine 10 according to the present disclosure is shown. As shown, the wind turbine 10 includes a tower 12 extending from a support surface 14, a nacelle 16 mounted on the tower 12, and a rotor 18 coupled to the nacelle 16. The rotor 18 includes a rotatable hub 20 and at least one rotor blade 22 coupled to the hub 20 and extending outwardly from the hub 20. For example, in the illustrated embodiment, the rotor 18 includes three rotor blades 22. However, in alternative embodiments, the rotor 18 may include more or less than three rotor blades 22. Each rotor blade 22 may be spaced about the hub 20 to facilitate rotating the rotor 18 to enable kinetic energy to be converted from the wind into usable mechanical energy, and subsequently into electrical energy. For example, the hub 20 may be rotatably coupled to an electric generator 24 ( Figure 2 ) to allow the generation of electrical energy.

[0032] See now Figure 2 , shows a simplified interior view of one embodiment of a nacelle 16 of a wind turbine 10. As shown, a generator 24 may be disposed within the nacelle 16. Generally, the generator 24 may be coupled to the rotor 18 of the wind turbine 10 for generating electrical power from the rotational energy generated by the rotor 18. For example, the rotor 18 may include a main shaft 40 coupled to the hub 20 for rotation therewith. The generator 24 may then be coupled to the main shaft 40 such that rotation of the main shaft 40 drives the generator 24. For example, in the illustrated embodiment, the generator 24 includes a generator shaft 42 that is rotatably coupled to the main shaft 40 via a gearbox 44. However, in other embodiments, it should be appreciated that the generator shaft 42 may be rotatably coupled directly to the main shaft 40. Alternatively, the generator 24 may be rotatably coupled directly to the main shaft 40.

[0033] It should be appreciated that the main shaft 40 may generally be supported within the nacelle 16 by a support frame or bedplate 46 positioned atop the wind turbine tower 12. For example, the main shaft 40 may be supported by the bedplate 46 via a pair of pillow blocks 48, 50 mounted thereon.

[0034] like Figure 1 and 2 As shown, the wind turbine 10 may also include a turbine control system or turbine controller 26 within the nacelle 16. For example, Figure 2 , the turbine controller 26 is disposed within a control cabinet 52 mounted to a portion of the nacelle 16. However, it should be appreciated that the turbine controller 26 may be disposed at any location on or in the wind turbine 10, at any location on the support surface 14, or generally at any other location. The turbine controller 26 generally may be configured to control various operating modes (e.g., startup or shutdown sequences) and / or components of the wind turbine 10.

[0035] Each rotor blade 22 may also include a pitch adjustment mechanism 32 configured to rotate each rotor blade 22 about its pitch axis 34. Furthermore, each pitch adjustment mechanism 32 may include a pitch drive motor 33 (e.g., any suitable electric, hydraulic, or pneumatic motor), a pitch drive gearbox 35, and a pitch drive pinion 37. In such an embodiment, the pitch drive motor 33 may be coupled to the pitch drive gearbox 35 such that the pitch drive motor 33 imparts mechanical force to the pitch drive gearbox 35. Similarly, the pitch drive gearbox 35 may be coupled to the pitch drive pinion 37 for rotation therewith. The pitch drive pinion 37, in turn, may rotationally engage with a pitch bearing 54 coupled between the hub 20 and the corresponding rotor blade 22, such that rotation of the pitch drive pinion 37 causes rotation of the pitch bearing 54. Thus, in such an embodiment, rotation of the pitch drive motor 33 drives the pitch drive gearbox 35 and the pitch drive pinion 37, thereby rotating the pitch bearing 54 and the rotor blade 22 about the pitch axis 34. Similarly, wind turbine 10 may include one or more yaw drive mechanisms 38 communicatively coupled to controller 26 , wherein each yaw drive mechanism(s) 38 is configured to change the angle of nacelle 16 relative to the wind (e.g., by engaging yaw bearing 56 of wind turbine 10 ).

[0036] In addition, the turbine controller 26 can also be controlled by a separate or integrated pitch controller 30 ( Figure 1 ) is communicatively coupled to each pitch adjustment mechanism 32 (one of which is shown) of wind turbine 10 for controlling and / or changing the pitch angle of rotor blades 22 (i.e., the angle that determines the viewing angle of rotor blades 22 relative to the direction 28 of the wind).

[0037] In addition, if Figure 2 As shown in FIG, one or more sensors 57, 58 may be provided on the wind turbine 10. More specifically, as shown, a wind sensor 58 may be provided on the wind turbine 10. For example, the wind sensor 58 may be a wind vane and anemometer, a LIDAR sensor, or other suitable sensor that measures wind speed and / or wind direction. Additionally, a pitch sensor 57 may be configured with each pitch drive mechanism 32, for example, to monitor various parameters of the pitch motor 33. As such, the sensors 57, 58 may further communicate with the controller 26 and may provide relevant information to the controller 26. For example, the pitch sensor(s) 59 may correspond to a temperature sensor that sends a temperature signal to the controller 26, 30 to indicate the actual temperature of the pitch battery, which will be described in more detail herein.

[0038] It should also be appreciated that, as used herein, the term "monitoring" and variations thereof indicate that the various sensors of wind turbine 10 may be configured to provide direct measurements of the parameters being monitored and / or indirect measurements of such parameters. Thus, for example, the sensors described herein may be used to generate signals related to the parameters being monitored, which may then be utilized by controller 26 to determine a condition.

[0039] See now Figure 3 , shows a block diagram of one embodiment of suitable components that may be included within the controller 26 according to the present disclosure. As shown, the controller 26 may include one or more processors 60 and associated memory devices 62, the memory devices being configured to perform various computer-implemented functions (e.g., perform methods, steps, calculations, etc., and store relevant data as disclosed herein). Additionally, the controller 26 may further include a communication module 64 to facilitate communication between the controller 26 and the various components of the wind turbine 10. Additionally, the communication module 64 may include a sensor interface 66 (e.g., one or more analog-to-digital converters) to allow signals transmitted from one or more sensors 57, 58 to be converted into signals that can be understood and processed by the processor 60. It should be appreciated that the sensors 57, 58 may be communicatively coupled to the communication module 64 using any suitable means. For example, Figure 3 As shown in FIG, the sensors 57, 58 are coupled to the sensor interface 66 via a wired connection. However, in other embodiments, the sensors 57, 58 may be coupled to the sensor interface 66 via a wireless connection, such as by using any suitable wireless communication protocol known in the art.

[0040] As used herein, the term "processor" refers not only to what is known in the art as an integrated circuit included in a computer, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and other programmable circuits. Furthermore, the memory device(s) 62 may generally include memory elements including, but not limited to, computer-readable media (e.g., random access memory (RAM), computer-readable non-volatile media (e.g., flash memory), floppy disks, compact disk read-only memory (CD-ROMs), magneto-optical disks (MODs), digital versatile disks (DVDs), and / or other suitable memory elements). Such memory device(s) 62 may generally be configured to store suitable computer-readable instructions that, when executed by the processor(s) 60, configure the controller 26 to perform various functions, including, but not limited to, transmitting suitable control signals to implement corrective action(s) in response to a distance signal exceeding a predetermined threshold as described herein, as well as various other suitable computer-implemented functions.

[0041] See now Figure 5-7, according to aspects of the present disclosure, systems and methods for preventing pitch bearing failures are shown. More specifically, Figure 5 A flow chart illustrating an embodiment of a method 100 for preventing pitch bearing failure of a pitch system according to the present disclosure is shown. Figure 6 A schematic diagram of one embodiment of a system 150 for preventing pitch bearing failure of a pitch system according to the present disclosure is shown. Figure 7 A schematic diagram of another embodiment of a system 150 for preventing pitch bearing failure of a pitch system according to the present disclosure is shown.

[0042] Specific reference Figure 5 In general, the method 100 is described herein as being implemented using, for example, the pitch system 70 described above. However, it should be appreciated that the disclosed method 100 may be implemented using any other suitable pitch system now known or later developed in the art. Figure 5 For the purpose of illustration and discussion, the steps performed in a particular order are depicted, but the methods described herein are not limited to any particular order or arrangement. Those skilled in the art using the disclosure provided herein will recognize that the various steps of the methods may be omitted, rearranged, combined, and / or adapted in various ways.

[0043] As shown at (102), method 100 includes monitoring one or more electrical signals of pitch motor 33 of pitch drive mechanism 32 of pitch system 70 via at least one sensor (e.g., sensor(s) 57). For example, in one embodiment, the electrical signal(s) may include, for example, current, voltage, power, and / or torque. For example, Figure 6 and 7 As shown in , the electrical signal(s) may be a pitch current.

[0044] Return to view Figure 5 As shown at (104), method 100 includes filtering the electrical signal(s) of pitch motor 33 for a predetermined period of time via at least one filter. For example, in one embodiment, the filter(s) may include a low-pass filter, a high-pass filter, a band-pass filter, or a combination thereof. More specifically, as Figure 6 and 7 As shown in , the pitch current may be filtered via a low pass filter 152 .

[0045] Return to view Figure 5As shown at (106), method 100 includes analyzing the electrical signal(s) of pitch motor 33, for example, via pitch system 70 and / or turbine controller 26, to remove noise and amplify outliers. For example, in one embodiment, method 100 may include determining an average drift in the electrical signal(s) of pitch motor 33 over a predetermined time period, and removing the average drift from the electrical signal(s) of pitch motor 33 over the predetermined time period to reduce noise in the operational signal(s) due to aerodynamic torsional moments on rotor blades 22.

[0046] In another embodiment, the method 100 may further include removing noise due to the pitch acceleration torque by detecting a component of the motor torque that leads the pitch rate in phase by ninety degrees (90°) and removing that component from the electrical signal(s). Additionally, the method 100 may include removing noise due to the aerodynamic steady-state torsional torque by detecting an average drift in the motor torque and removing the average drift from the electrical signal(s). In such an embodiment, the method 100 may include normalizing the measure of friction with the pitch stroke and bearing load, for example, to further improve diagnostic accuracy and make the method 100 robust to variations in pitch stroke and load.

[0047] Therefore, if Figure 6 As shown at block 154 in FIG. 1 , in one embodiment, pitch system 70 may be configured to analyze the electrical signal(s) of pitch motor 33 by modifying the pitch current using at least one of the root mean square, standard deviation, and / or power of pitch motor 33 to obtain modified current value 156. As shown at 158, turbine controller 26 may then determine a maximum value within a time interval (such as 10 minutes). Such a maximum value may also be stored, for example, in global data repository 162 of field-level controller 160. Thus, by monitoring the maximum value of the pitch current, system 150 provides improved detection of pitch bearing faults.

[0048] More precisely, refer back to Figure 5 As shown at (108), method 100 also includes estimating bearing friction of pitch bearing 54 using the analyzed electrical signal(s) of pitch motor 33. For example, in one embodiment, bearing friction may be estimated by generating a predictive computer model of pitch bearing 54 via turbine controller 26 using the electrical signal(s) of pitch motor 33 and one or more operational signals of pitch system 70. For example, in one embodiment, the operational signal(s) of pitch system 70 may include temperature of pitch drive mechanism 32, ball bearing friction, cage stress, operating hours, thrust, brake activation, or pitch activity.

[0049] More precisely, if Figure 7As shown in , the pitch action may include pitch rate, pitch motor energy per degree of pitch travel, pitch amount, pitch angle, or any other suitable pitch action. Additionally, as shown at 166, the pitch torque may be determined based on the pitch current. Additionally, as shown at 168, the pitch rate may be used to determine the pitch power, for example, by multiplying the pitch torque by the pitch rate. Additionally, as shown at 169, the pitch torque may be determined based on the pitch current. Figure 7 As shown in , the pitch rate can be used to determine the pitch stroke, for example, by determining the absolute value of the pitch rate, as shown at 170. In addition, as shown, the pitch stroke can also be filtered via a low-pass filter 153. The outputs 172, 173 of the low-pass filters 152, 153 represent the average friction power and the average pitch stroke rate, respectively. Therefore, as shown, the controller 26 can determine the friction work 176, which can be used to indicate an abnormality in the pitch bearing 54.

[0050] Therefore, in certain embodiments, Figures 8A-8C As shown in , the method 100 may include generating a thermal map 164 of the pitch bearing 54 based on wind speed and time over a predetermined time period using the changed current value. For example, in one embodiment, the method 100 may include generating a thermal map 164 of the pitch bearing 54 using a digital twin model. Thus, as Figures 8A-8C As shown in the figure, the damaged pitch bearing ( Figure 8B ) may be easily detected, for example, by comparing thermal maps for all pitch bearings 54 on all of the rotor blades 22 of the wind turbine 10 .

[0051] Return to view Figure 5 , as shown at (110), the method 100 includes implementing a control action via the turbine controller 26 when the estimated bearing friction of the pitch bearing 54 indicates an anomaly in the pitch bearing 54. For example, in one embodiment, the method 100 may include determining the friction power loss of the pitch bearing 54, for example, from the thermal map 164. Thus, in certain embodiments, implementing the control action when the estimated bearing friction of the pitch bearing 54 indicates an anomaly in the pitch bearing 54 may include implementing the control action when the friction power loss of the pitch bearing 54 exceeds a predetermined threshold.

[0052] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If such other embodiments include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims, such other examples are intended to be within the scope of the claims.

Claims

1. A method for preventing a pitch bearing failure of a pitch system of a wind turbine, the method comprising: monitoring, via at least one sensor, one or more electrical signals of a pitch motor of a pitch drive mechanism of the pitch system, the pitch motor driving a pitch bearing of the pitch system; analyzing, via a controller, one or more electrical signals of the pitch motor to remove noise and amplify outliers; estimating bearing friction of the pitch bearing using the analyzed one or more electrical signals of the pitch motor; as well as implementing a control action via the controller when the estimated bearing friction of the pitch bearing indicates an abnormality in the pitch bearing, wherein analyzing the one or more electrical signals of the pitch motor to remove the noise and amplify abnormal values ​​further comprises filtering the one or more electrical signals of the pitch motor within a predetermined time period, and Wherein filtering the one or more electrical signals of the pitch motor within the predetermined time period further comprises: determining an average drift in one or more electrical signals of the pitch motor over the predetermined time period; as well as An average drift is removed from one or more electrical signals of the pitch motor over the predetermined time period to reduce noise in the one or more operational signals due to aerodynamic twisting torque on the rotor blades.

2. The method according to claim 1, wherein The one or more electrical signals include at least one of current, voltage, power, or torque.

3. The method according to claim 2, wherein: Using the analyzed one or more electrical signals of the pitch motor to estimate bearing friction of the pitch bearing also includes generating, via the controller, a predictive computer model of the pitch bearing using the one or more electrical signals of the pitch motor and one or more operational signals of the pitch system.

4. The method according to claim 3, wherein: The one or more operational signals of the pitch system include at least one of temperature, ball bearing friction, cage stress, operating hours, thrust, brake activation, or pitch activity of the pitch drive mechanism.

5. The method according to claim 4, wherein The pitch activity includes at least one of pitch motor energy per degree of pitch stroke, pitch amount, or pitch angle.

6. The method according to claim 5, wherein: The one or more electrical signals of the pitch motor include current, and wherein analyzing the one or more electrical signals of the pitch motor to remove noise and amplify outliers further comprises: varying the current using at least one of a root mean square, a standard deviation, or a power of the pitch motor to obtain a varied current value; and A thermal map of the pitch bearing is generated based on wind speed and time within the predetermined time period using the changed current value.

7. The method according to claim 6, wherein: Estimating bearing friction of the pitch bearing using the analyzed one or more electrical signals of the pitch motor also includes determining frictional power losses of the pitch bearing from the thermal map.

8. The method of claim 6, further comprising generating a thermal map of the pitch bearing using a digital twin model.

9. The method according to claim 6, wherein: Implementing the control action when the estimated bearing friction of the pitch bearing indicates an anomaly in the pitch bearing further includes implementing the control action when frictional power loss of the pitch bearing exceeds a predetermined threshold.

10. A system for preventing pitch bearing failure of a pitch system of a wind turbine, the system comprising: at least one sensor configured to monitor one or more electrical signals of a pitch motor of a pitch drive mechanism of the pitch system, the pitch motor driving a pitch bearing of the pitch system; a controller communicatively coupled to the at least one sensor, the controller comprising at least one processor configured to perform a plurality of operations comprising: analyzing one or more electrical signals of the pitch motor to remove noise and amplify outliers; estimating bearing friction of the pitch bearing using the analyzed one or more electrical signals of the pitch motor; and implementing a control action when the estimated bearing friction of the pitch bearing indicates an anomaly in the pitch bearing, wherein analyzing the one or more electrical signals of the pitch motor to remove the noise and amplify abnormal values ​​further comprises filtering the one or more electrical signals of the pitch motor within a predetermined time period, and Wherein filtering the one or more electrical signals of the pitch motor within the predetermined time period further comprises: determining an average drift in one or more electrical signals of the pitch motor over the predetermined time period; and An average drift is removed from one or more electrical signals of the pitch motor over the predetermined time period to reduce noise of the one or more operating signals.

11. The system according to claim 10, wherein: The one or more electrical signals include at least one of current, voltage, power, or torque.

12. The system according to claim 11, wherein Using the analyzed one or more electrical signals of the pitch motor to estimate bearing friction of the pitch bearing also includes generating a predictive computer model of the pitch bearing using the one or more electrical signals of the pitch motor and one or more operational signals of the pitch system.

13. The system according to claim 12, wherein: The one or more electrical signals of the pitch motor include current, and wherein analyzing the one or more electrical signals of the pitch motor to remove noise and amplify outliers further comprises: varying the current using at least one of a root mean square, a standard deviation, or a power of the pitch motor to obtain a varied current value; and A thermal map of the pitch bearing is generated based on the wind speed within the predetermined time period using the changed current value.

14. The system according to claim 13, wherein: Using the analyzed one or more electrical signals of the pitch motor to estimate the bearing friction of the pitch bearing also includes determining the friction power loss of the pitch bearing from the thermal map, and wherein, implementing the control action when the estimated bearing friction of the pitch bearing indicates an abnormality of the pitch bearing also includes implementing the control action when the friction power loss of the pitch bearing exceeds a predetermined threshold.

Images