System and method for predicting pitch faults in a wind turbine

Abstract

This disclosure relates to a method (100, 200) for predicting blade jamming events during power generation in a wind turbine (10), the wind turbine (10) including a rotor (18) having a plurality of blades (22) and a pitch system (32) for each of the blades (22), the pitch system (32) being configured to rotate the corresponding blade (22) along its longitudinal axis. The method includes monitoring one or more operating parameters of a first pitch system (32) and a second pitch system (32), and predicting, at least in part, a blade jamming event during power generation in one of the blades (22) connected to the first pitch system (32) or the second pitch system (32), based on the monitored operating parameters of the first pitch system (32) and the monitored operating parameters of the second pitch system (32). The method also includes that the operating parameters to be monitored for the first pitch system and the second pitch system have been predetermined in an analysis for the event. In another aspect, this disclosure relates to a control system (80) for a wind turbine (10), which is configured to perform such methods (100, 200) for monitoring the wind turbine (10).

Description

Technical Field

[0001] This disclosure relates to wind turbines, and more particularly, to systems and methods for monitoring wind turbines to predict failures that could cause blade jamming during power generation. Background Technology

[0002] Modern wind turbines are commonly used to supply electricity to the power grid. Such a wind turbine generally consists of a tower and a rotor mounted on the tower. The rotor, typically comprising a hub and multiple blades, begins to rotate under the influence of wind on the blades. This rotation generates torque, which is typically transmitted directly (“direct-drive” or “gearless”) or via a gearbox through the rotor shaft to a generator. The generator then produces electricity that can be supplied to the power grid.

[0003] The wind turbine hub can be rotatably coupled to the front of the nacelle. The wind turbine hub can be connected to the rotor shaft, and the rotor shaft can then be rotatably mounted in the nacelle using one or more rotor shaft bearings arranged in a frame inside the nacelle. The nacelle is a shell arranged on top of the wind turbine tower that houses and protects the gearbox (if present) and generator (if not placed outside the nacelle), and, depending on the wind turbine, houses and protects additional components such as power converters and auxiliary systems.

[0004] During operation, wind conditions supplying power to the wind turbine may change. In variable-speed wind turbines, the turbine controller can alter the turbine's control settings to adapt to changing wind conditions. Specifically, the blade pitch angle and generator torque can be adjusted to suit the wind conditions. At wind speeds below the nominal or "rated" wind speed, the control objective is generally to maximize the wind turbine's electrical power output, i.e., changing the blade pitch and generator torque to deliver the maximum electrical power output to the grid. At wind speeds above the nominal speed (and depending on conditions near the nominal speed), the control objective may specifically be to keep the load under control, i.e., changing the blade pitch and generator torque to reduce the load on the wind turbine to an acceptable level while maintaining the power output at the highest possible level (considering load limitations).

[0005] To change the blade pitch angle, a wind turbine may include a blade pitch system for each blade. The blade pitch system typically includes a bearing comprising an outer ring, an inner ring, and one or more rows of rolling elements that allow the two rings to rotate relative to each other. One of the inner and outer rings is fixed to the wind turbine blade, while the other is fixed to the hub. An actuator mechanism is arranged to rotate the blade. For this purpose, hydraulic or electromechanical actuators may be used.

[0006] To ensure the structural integrity of wind turbines, they are designed to withstand extreme and fatigue loads under various conditions or events. For this purpose, the lifespan of a wind turbine can be represented by numerous design cases covering the most critical conditions a wind turbine can experience. These design cases are characterized by so-called Design Load Cases (DLCs). Therefore, multiple design load cases are predetermined to specify different wind conditions (and, for offshore wind turbines, wave conditions). Furthermore, not only environmental conditions but also the wind turbine's own operating modes are considered. Thus, different DLCs are defined for conditions including power generation, turbine startup, normal shutdown, emergency shutdown, or complete stoppage (stationary or idling). Additionally, design load cases can be defined for situations combining power generation with failures in components such as the power grid or the wind turbine itself.

[0007] Depending on the installation location and / or characteristics of the wind turbine, different design load conditions can be factors in determining the dimensions of components for the wind turbine. For this reason, identifying and addressing the design load conditions that lead to the most severe consequences for the wind turbine is particularly important. Furthermore, in cases involving failure, early identification and mitigation of failures may be especially valuable.

[0008] Particularly significant design load conditions include events in which the wind turbine is experiencing a fault and one of the rotor blades remains stuck while the turbine is in power generation mode (i.e., not during shutdown). This event, characterized by one of the design load conditions mentioned above, can become a driving load condition for several components of the wind turbine, ranging from the hub to the base of the tower.

[0009] Therefore, improved systems and methods for handling design load conditions are desired. In particular, it is desirable to achieve the prediction of blade jamming events during power generation. The ability to predict events can lead to earlier implementation of appropriate actions to mitigate the impact of the events. By doing so, more optimized design of wind turbine components can be achieved, and improved wind turbine availability can be obtained.

[0010] This disclosure aims to provide systems and methods for addressing at least one of the aspects mentioned above. Summary of the Invention

[0011] In one aspect of this disclosure, a method is provided for predicting blade jamming events in a wind turbine during power generation. The wind turbine includes a rotor having a plurality of blades and a pitch system for each of the blades. The pitch system is configured to rotate the corresponding blade along its longitudinal axis. The method includes monitoring one or more operating parameters of a first pitch system and a second pitch system. The method also includes predicting a blade jamming event in one of the blades connected to the first or second pitch system during power generation. The prediction is based at least in part on the operating parameters monitored by the first and second pitch systems. The operating parameters to be monitored by the first and second pitch systems are predetermined in an analysis for the event.

[0012] This enables early detection of faults in the pitch system, allowing for the prediction of blade jamming events during power generation caused by detected faults. Therefore, appropriate measures can be implemented proactively. These measures can provide a better response to anticipated blade jamming events. In some cases, appropriate measures can mitigate the effects of identified faults, which may help reduce the probability of blade jamming events occurring themselves.

[0013] In order to detect the presence of faults and predict the occurrence of blade jamming events, it is necessary to monitor a number of operating parameters for at least the first pitch system and the second pitch system, each of which is connected to the corresponding blade.

[0014] The operating parameters to be monitored are not arbitrary; rather, they are specific operating parameters defined by analysis of blade jamming events during power generation. This analysis allows for the identification of faults whose effects can serve as precursors to blade jamming events during power generation. In other words, it identifies one or more fault paths leading to such events, enabling appropriate action to be taken after the initial effects of the fault are detected. Such actions may include mitigating the effects of the detected fault, thereby effectively reducing the probability of blade jamming events occurring. The operating parameters may relate to the electrical and mechanical characteristics of different components of the pitch system, including, for example, actuators and sensors.

[0015] Furthermore, this prediction does not require detailed models and / or complex algorithms, but instead relies on signals from at least one adjacent blade pitch system. In fact, this disclosure utilizes the fact that multiple blades are arranged in the rotor of a wind turbine. Moreover, the pitch systems corresponding to the wind turbine blades have identical components and operate under substantially the same operating conditions. Therefore, each blade pitch system can be monitored using signals from at least one adjacent blade pitch system. By using information received from multiple blades, a robust and simple method is provided for identifying outliers, which, together with prior analysis, allow for the prediction of blade jamming events during power generation.

[0016] Throughout this disclosure, a blade jamming event can be considered as an event in which a fault prevents the blade from rotating about its longitudinal axis, i.e., an event in which a fault prevents the blade from pitching.

[0017] Throughout this disclosure, the “prediction” of an event can be considered as providing an indication of a potential (failure) event prior to the actual (failure) event occurring. The prediction does not need to be made long before the event occurs, but in a preferred example, the prediction is made long enough before the event occurs that the event can be avoided or at least its consequences can be avoided or mitigated.

[0018] In another aspect of this disclosure, a further example of a method for monitoring a wind turbine includes a rotor with multiple blades and a pitch system for each blade. In this example, the method includes monitoring one or more operating parameters of all pitch systems. The method also includes predicting a blade jamming event during power generation in one of the blades connected to one of the pitch systems, based at least in part on a comparison of the monitored operating parameters of all pitch systems. The method according to this example also includes that the operating parameters to be monitored have been pre-determined in a Failure Mode and Effects Analysis (FMEA). The FMEA analysis is used to identify failure paths leading to a blade jamming event during power generation.

[0019] According to this example of the disclosure, a robust and reliable method is obtained by using and comparing information from all available pitch systems in a wind turbine. Furthermore, failure mode and effects analysis (FMEA) is performed, which enables the identification and characterization of pitch system failures, through their corresponding effects, in an organized and comprehensive manner, ultimately leading to events including blade jamming during power generation.

[0020] In another aspect of this disclosure, a control system for a wind turbine is provided. The wind turbine includes a rotor having a plurality of blades and a pitch system for each of the blades, the pitch system being configured to rotate the corresponding blade along its longitudinal axis. The control system is configured to perform a method according to any example of the aspects mentioned above. In particular, the control system is configured to monitor one or more operating parameters of a first pitch system and a second pitch system, and to predict a blade jamming event in one of the blades connected to the first or second pitch system during power generation. The prediction is based at least in part on the operating parameters monitored by the first pitch system and the second pitch system. Furthermore, the operating parameters to be monitored by the first and second pitch systems are predetermined in an analysis for the event. Attached Figure Description

[0021] Figure 1 A perspective view showing an example of a wind turbine; Figure 2 Show Figure 1 A simplified interior view of an example wind turbine nacelle; Figure 3 An example of a pitch system is shown schematically; Figure 4 An electronic converter unit for a pitch system is schematically shown according to an example; Figure 5 The architecture of a monitoring method for wind turbines, based on an example, is illustrated schematically. Figure 6 An aspect of the architecture of a monitoring method for wind turbines, based on an example, is illustrated schematically. Figure 7 A flowchart illustrating an example of a method for monitoring wind turbines to predict blade jamming events during power generation; Figure 8 A flowchart illustrating another example of a method for monitoring wind turbines to predict blade jamming events during power generation. Detailed Implementation

[0022] Reference will now be made in detail to embodiments, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation only and not as a limitation. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in this disclosure. For example, a feature shown or described as part of one example may be used with another example to produce yet another example. Therefore, it is intended that this disclosure cover such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0023] Figure 1This is a perspective view of an example wind turbine 10. In this example, the wind turbine 10 is a horizontal axis wind turbine. Alternatively, the wind turbine 10 may be a vertical axis wind turbine. In this example, the wind turbine 10 includes a tower 15 extending from a support system 14 on the ground 12, a nacelle 16 mounted on the tower 15, 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 and extending outward from the hub 20. In this example, the rotor 18 has three rotor blades 22. In an alternative embodiment, the rotor 18 includes more or fewer than three rotor blades 22. The tower 15 may be made of tubular steel to define a cavity between the support system 14 and the nacelle 16. Figure 1 (Not shown in the image). In an alternative embodiment, tower 15 is any suitable type of tower with any suitable height. According to the alternative, the tower may be a hybrid tower comprising sections made of concrete and tubular steel sections. Furthermore, the tower may be a partially lattice or fully lattice tower.

[0024] Rotor blades 22 are spaced around hub 20 to facilitate the rotation of rotor 18, thereby converting kinetic energy from wind into usable mechanical energy, and subsequently into electrical energy. Rotor blades 22 are fitted to hub 20 by connecting blade root regions 24 to multiple load transfer regions 26. Load transfer regions 26 may have hub load transfer regions and blade load transfer regions (neither of which are located in the hub). Figure 1 (As shown in the figure). The load caused by the rotor blades 22 is transmitted to the hub 20 via the load transfer area 26.

[0025] In the example, rotor blade 22 may have a length ranging from about 15 meters (m) to about 90 meters or longer. Rotor blade 22 may have any suitable length that enables the wind turbine 10 to function as described herein. For example, non-limiting examples of blade length include lengths of 20 meters or less, 37 meters, 48.7 meters, 50.2 meters, 52.2 meters, or greater than 91 meters. When wind impacts rotor blade 22 from wind direction 28, rotor 18 rotates about rotor axis 30. As rotor blade 22 rotates and experiences centrifugal force, it also experiences various forces and moments. Therefore, rotor blade 22 may deflect and / or rotate from a neutral or non-deflected position to a deflected position.

[0026] Furthermore, the pitch angle of the rotor blade 22, i.e., the angle determining the orientation of the rotor blade 22 relative to the wind direction, can be changed by the pitch system 32 to control the load and power output generated by the wind turbine 10 by adjusting the angular position of at least one rotor blade 22 relative to the wind vector. The pitch axis 34 of the rotor blade 22 is shown. During the operation of the wind turbine 10, the pitch system 32 can specifically change the pitch angle of the rotor blade 22 such that the angle of attack of the rotor blade (partially) is reduced, which promotes a reduction in the rotor's rotational speed and / or promotes the stall of the rotor 18.

[0027] In this example, the blade pitch of each rotor blade 22 is individually controlled by the wind turbine controller 36 or by the pitch control system 80. Alternatively, the blade pitch for all rotor blades 22 can be simultaneously controlled by the control system.

[0028] Furthermore, in this example, when the wind direction 28 changes, the nacelle 16 can rotate about the longitudinal axis of the tower, i.e., about the yaw axis 38, to position the rotor blades 22 relative to the wind direction 28.

[0029] In this example, the wind turbine controller 36 is shown as centralized within the nacelle 16; however, the wind turbine controller 36 may be a distributed system located at various points on the wind turbine 10, on the support system 14, within the wind farm, and / or at a remote control center. The wind turbine controller 36 may include a processor 40 configured to perform some of the methods and / or steps described herein. Furthermore, many other components described herein include processors.

[0030] As used herein, the term "processor" is not limited to an integrated circuit referred to in the art as a computer, but broadly refers to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits (ASICs), and other programmable circuits, and these terms are used interchangeably herein. It should be understood that processors and / or control systems may also include memory, input channels, and / or output channels.

[0031] The control system 36 may also include memory, such as one or more memory devices. The memory may include one or more 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, optical disc read-only memory (CD-ROM), magneto-optical disc (MOD), digital versatile optical disc (DVD), and / or other suitable memory elements. One or more such memory devices may be generally configured to store suitable computer-readable instructions that, when implemented by one or more processors 40, configure the controller 36 to perform or trigger the execution of the various steps disclosed herein. The memory may also be configured to store data, such as data from measurements and / or calculations.

[0032] Figure 2 This is an enlarged cross-sectional view of a portion of a wind turbine 10. In this example, the wind turbine 10 includes a nacelle 16 and a rotor 18 rotatably coupled to the nacelle 16. More specifically, the hub 20 of the rotor 18 is rotatably coupled to a generator 42 located within the nacelle 16 via a main shaft 44, a gearbox 46, a high-speed shaft 48, and a coupling 50. In this example, the main shaft 44 is at least partially coaxial with the longitudinal axis (not shown) of the nacelle 16. The rotation of the main shaft 44 drives the gearbox 46, which in turn drives the high-speed shaft 48 by converting the relatively slow rotational motion of the rotor 18 and the main shaft 44 into a relatively fast rotational motion of the high-speed shaft 48. The high-speed shaft 48 is connected to the generator 42 to generate electrical energy via the coupling 50. In addition, a transformer 90 and / or suitable electronic equipment, switches and / or inverters can be arranged in the nacelle 16 to convert electrical energy generated by the generator 42 with a voltage between 400 V and 1000 V into electrical energy with a medium voltage (e.g., 10-35 kV). The electrical energy is conducted from the nacelle 16 to the tower 15 via power cables.

[0033] The gearbox 46, generator 42, and transformer 90 can be supported by the main support structure frame of the nacelle 16, which may optionally be embodied as the main frame 52. The gearbox 46 may include a gearbox housing connected to the main frame 52 via one or more torque arms 55. In this example, the nacelle 16 also includes a main front support bearing 60 and a main rear support bearing 62. Furthermore, the generator 42 can be mounted to the main frame 52 by disengaging the support device 54, particularly to prevent vibrations of the generator 42 from being introduced into the main frame 52 and thus becoming a source of noise.

[0034] Optionally, the main frame 52 is configured to bear the weight of the rotor 18 and the components of the nacelle 16, as well as all loads caused by wind and rotational loads, and further, to introduce these loads into the tower 15 of the wind turbine 10. The rotor shaft 44, generator 42, gearbox 46, high-speed shaft 48, coupling 50, and any associated fastening, support, and / or fixing devices (including, but not limited to, support members 52, and front support bearings 60 and rear support bearings 62) are sometimes referred to as the drivetrain 64.

[0035] In some examples, the wind turbine may be a direct-drive wind turbine without gearbox 46. The generator 42 operates in the direct-drive wind turbine at the same rotational speed as the rotor 18. Therefore, they generally have a much larger diameter than the generators used in wind turbines with gearbox 46, in order to provide a similar amount of power as wind turbines with gearboxes.

[0036] The nacelle 16 may also include a yaw system comprising a yaw bearing having two bearing members configured to rotate relative to each other. Figure 2 (Not visible in the middle). The tower 15 is connected to one of the bearing components, and the bottom plate or support frame 52 of the nacelle 16 is connected to the other bearing component.

[0037] The yaw system may include a ring gear 31 and a yaw drive mechanism 56, which can be used to rotate the nacelle 16 and thus cause the rotor 18 to also rotate about the longitudinal axis of the tower, i.e., about the yaw axis 38, to control the angle of the rotor blades 22 relative to the wind direction 28.

[0038] The yaw drive mechanism 56 may include a plurality of yaw drives 35 having a motor 33, a gearbox 37, and a pinion 39 for meshing with a ring gear 31 to rotate one of the bearing members relative to another. The ring gear 31 may include a plurality of teeth that engage with the teeth of the pinion 39. Figure 2 In one example, the yaw actuator 35 and the ring gear 31 are positioned outside the outer diameter of the tower. The teeth of the ring gear are oriented outwards, but in other examples, the ring gear and the yaw actuator may be arranged inside the tower.

[0039] In some examples, one of the yaw drives may be the "master drive" and the other drives may be the "slave drives" that follow the master drive's instructions or adjust their operation to suit the master drive.

[0040] The turbine controller 36 is communicatively coupled to the yaw drive mechanism 56 of the wind turbine 10 to control and / or change the yaw direction of the nacelle 16 relative to the wind direction 28. When the wind direction 28 changes, the turbine controller 36 can be configured to control the yaw angle of the nacelle 16 about the longitudinal axis or yaw axis 38 of the tower to position the rotor blades 22 and thus the rotor 18 relative to the wind direction 28, thereby controlling the loads acting on the wind turbine 10. For example, the turbine controller 36 can be configured to transmit control signals or commands to the yaw drive mechanism 56 of the wind turbine 10 via a yaw controller or direct transmission, such that the nacelle 16 can rotate about the longitudinal axis or yaw axis 38 of the tower via a yaw bearing.

[0041] To properly position the nacelle 16 relative to wind direction 28, the nacelle 16 may also include at least one meteorological measurement system, which may include a wind vane and an anemometer. The meteorological measurement system 58 may provide the wind turbine controller 36 with information that may include wind direction 28 and / or wind speed.

[0042] In this example, the pitch system 32 is arranged at least partially as a pitch assembly 66 in the hub 20. The pitch assembly 66 includes one or more pitch drive systems 68 and at least one sensor 70. Each pitch drive system 68 is coupled to a corresponding rotor blade 22. Figure 1 (As shown in the figure), the pitch angle of the rotor blades 22 is adjusted along the pitch axis 34. Figure 2 Only one of the three pitch drive systems 68 is shown in the image.

[0043] In this example, the pitch assembly 66 includes at least one pitch bearing 72, which is coupled to the hub 20 and the corresponding rotor blades 22. Figure 1 (As shown in the diagram), so that the corresponding rotor blades 22 rotate about the pitch axis 34. The pitch drive system 68 includes a pitch drive motor 74, a pitch drive gearbox 76, and a pitch drive pinion 78. The pitch drive motor 74 is coupled to the pitch drive gearbox 76 such that the pitch drive motor 74 applies mechanical force to the pitch drive gearbox 76. The pitch drive gearbox 76 is coupled to the pitch drive pinion 78 such that the pitch drive pinion 78 is rotated by the pitch drive gearbox 76. The pitch bearing 72 is coupled to the pitch drive pinion 78 such that rotation of the pitch drive pinion 78 causes rotation of the pitch bearing 72.

[0044] The pitch drive system 68 is coupled to the wind turbine controller 36 to adjust the pitch angle of the rotor blades 22 upon receiving one or more signals from the wind turbine controller 36. In this example, the pitch drive motor 74 is any suitable motor driven by an electric power and / or hydraulic system that enables the pitch assembly 66 to function as described herein. Alternatively, the pitch assembly 66 may include any suitable structure, configuration, arrangement, and / or components, such as, but not limited to, hydraulic cylinders, springs, and / or servo mechanisms. In some embodiments, the pitch drive motor 74 is driven by energy extracted from the rotational inertia of the hub 20 and / or from a stored energy source (not shown) that supplies energy to the components of the wind turbine 10.

[0045] The pitch assembly 66 may also include one or more pitch control systems 80 for controlling the pitch drive system 68 based on control signals from the wind turbine controller 36, particularly in specific priority situations and / or during rotor 18 overspeed. In this example, the pitch assembly 66 includes at least one pitch control system 80 communicatively coupled to the corresponding pitch drive system 68 for controlling the pitch drive system 68 independently of the wind turbine controller 36. In this example, the pitch control system 80 is coupled to the pitch drive system 68 and the sensor 70. During normal operation of the wind turbine 10, the wind turbine controller 36 may control the pitch drive system 68 to adjust the pitch angle of the rotor blades 22.

[0046] According to one embodiment, a power generator 84, including, for example, a battery and a capacitor, is arranged at or within the hub 20 and coupled to the sensor 70, the pitch control system 80, and the pitch drive system 68 to provide a power source to these components. In this example, the power generator 84 provides a continuous power source to the pitch assembly 66 during operation of the wind turbine 10. In an alternative embodiment, the power generator 84 provides power to the pitch assembly 66 only during an electrical power loss event of the wind turbine 10. Electrical power loss events may include power grid loss or decline, malfunction of the electrical system of the wind turbine 10, and / or failure of the wind turbine controller 36. During an electrical power loss event, the power generator 84 operates to provide electrical power to the pitch assembly 66, enabling the pitch assembly 66 to operate during the electrical power loss event.

[0047] In this example, the pitch drive system 68, sensor 70, pitch control system 80, cables, and power generator 84 are each positioned within a cavity 86 defined by the inner surface 88 of the hub 20. In an alternative embodiment, the components are positioned relative to the outer surface of the hub 20 and may be directly or indirectly coupled to the outer surface.

[0048] Figure 3A portion of a pitch system 32 according to one example is shown. The pitch system 32 includes a pitch bearing 72 having a first inner bearing ring 721 coupled to a blade 22 and a second outer bearing ring 722 coupled to a hub 20. In other examples of this disclosure, the opposite arrangement may be used, i.e., the inner ring 721 may be coupled to the hub 20 and the outer ring 722 may be coupled to the blade 22. In any case, the pitch system 32 may include a pitch bearing 72 connecting the blade 22 to the hub 20. The pitch system 32 may also include a pitch motor 74, a pitch brake 77, a pitch gearbox 76, and a pitch pinion 78. Furthermore, although... Figure 3 Not shown, but the pitch system may also include at least one limit switch.

[0049] The inner ring of bearing 721 may include a ring gear 73. In this example, the pitch motor 74 is an electric motor fixed to the hub 20 of the wind turbine 10. The pitch gearbox 76 is arranged to operate as a reduction gear, and the pitch pinion 78 is arranged to mesh with the ring gear 73, i.e., the rapid rotation of the motor at low torque is converted by the pitch gearbox to the slower rotation of the pinion with higher torque. The rotation of the motor 74 then causes the pitch pinion 78 to rotate relative to the ring gear 73 connected to the first inner ring 721 of the bearing. As a result, the blade 22 can rotate relative to the hub 10.

[0050] Other configurations are also possible, such as, for example, the ring gear 73 being coupled to the outer ring 722 of the bearing, and the assembly including the pitch motor 73, the pitch gearbox 76, and the pitch pinion 78 being fixed to the blade 22 rather than to the hub 20. In even more advanced examples of this disclosure, a hydraulic actuator including a piston can be used in a so-called hydraulic pitch system.

[0051] like Figure 3 As also shown, examples of this disclosure may include an electronic converter unit 75. The application of the electronic converter unit 75 in a pitch system is known in the art, and therefore specific details will not be provided in this disclosure. The electric pitch motor 74 may be an AC motor, or alternatively a DC motor. Depending on the motor type, different topologies may be used for the electronic converter unit 75. More specifically, in the case of an AC pitch motor 74, the electronic converter unit 75 may include an AC-to-DC converter 751 (i.e., a rectifier), a DC link 753 (e.g., in the form of a capacitor bank), and a DC-to-AC power converter 752 (an inverter). Figure 4 An example of such an electronic converter unit 75 is shown. Figure 4In the example shown, a controllable switch can be used for both the rectifier 751 and the inverter 752, thus making this a back-to-back electronic converter 75. Other examples are also possible. Therefore, a passive rectifier including diodes can also be used in the electronic converter unit 75 to control the pitch system 32.

[0052] Figure 3 A pitch controller 80 is also schematically shown, which controls the operation of the pitch system 32, causing the blades 22 to pitch as needed. In some examples, a dedicated pitch system controller 80 may be used, while in other examples, the pitch control function may be implemented in the wind turbine controller 36. In a further example, the wind turbine controller 36 may be used to control the pitch of the blades 22 during normal operating conditions, while a specific pitch controller 80 may be used to control the blade pitch in emergency or abnormal operating conditions.

[0053] Figure 5 The architecture of a monitoring system according to an example is schematically illustrated. In this example, consider a wind turbine 10 comprising three blades 22. The pitch system 32 of each blade 22 can be monitored by a suitable sensor system 501 to collect operating parameters.

[0054] Information from sensor system 501 can be correlated with both electrical and mechanical failures in different components of pitch system 32. The collected information can be analyzed in processing block 502, which can be configured to compare sensor data received from at least two pitch systems and detect abnormal deviations and / or outliers. Within block 502, different modules (502a-502n) can be implemented to analyze data for specific operating parameters; for example, different blocks can be implemented to analyze the condition of one or more pitch motors 74, one or more pitch electronic converter units 75, one or more limit switches, one or more pitch bearings 72, etc. In each case, both electrical and / or mechanical characteristics can be considered.

[0055] As an example, the pitch bearing 72 can be damaged due to mechanical disturbances within the bearing raceway. Vibration can occur at a specific frequency when the rolling elements pass over a defective location in the bearing raceway. Such vibrations can be observed by analyzing the torque or stator current of the pitch motor 74, where they may manifest as harmonic components and / or ripple. By monitoring these operating parameters across multiple blades, faults can be detected and blade jamming events can be predicted.

[0056] As another example, electrical faults in the stator of the pitch motor 74 can also be detected by analyzing the harmonic components of the motor torque and / or motor current. This analysis can be performed in the frequency domain or the time domain. By collecting information from the same components in multiple pitch systems, blade jamming events can be predicted.

[0057] In the examples of this disclosure, operating parameters may include at least one of pitch motor torque, pitch motor current, pitch motor temperature, or pitch motor vibration. In particular, pitch motor vibration can be used to anticipate potential failures in the internal bearings of the pitch motor 74. By collecting vibration information for multiple pitch systems 32, abnormal deviations can be detected and blade jamming events can be predicted. Vibration data can be obtained via an accelerometer sensor placed within the pitch motor 74.

[0058] In a pitch system including an electronic converter unit 75, operating parameters according to examples of this disclosure may include at least one of DC link voltage, DC link current, output voltage, input current, DC link capacitance, or temperature of the electronic converter unit 75. Therefore, monitoring the DC link voltage or current can be used to determine the health of the DC link capacitor bank. In some cases, operating parameters can be measured directly, while in others they can be estimated. As an example, the DC link current can be obtained from, for example,... Figure 4 The three-phase currents measured at both the rectifier and inverter sides of a back-to-back converter, as depicted in the diagram, are estimated.

[0059] In one example, monitoring the operating parameters of at least the first and second pitch systems includes monitoring the operating parameters of all pitch systems. Therefore, in Figure 5 In the specific example shown, sensor data for all three pitch systems 32 can be collected in block 501. By collecting information from all three blades, a more robust, reliable, and easily interpretable predictive system can be achieved. In particular, a voting system can be established when comparing sensor data from the three pitch systems, allowing easy detection of anomalous behavior in that particular pitch system by recognizing potential deviations in just one of the pitch systems.

[0060] Box 502 may generate a signal, such as an error flag, to transmit detected deviations or outliers to supervisory layer 503. Supervisory layer 503 may be configured to receive signals or flags from processing box 502 and estimate the probability of blade jamming events during power generation in order to predict the occurrence of such events. If an event is predicted by supervisory layer 503, a signal or alarm may be generated and sent to wind turbine controller 36 for appropriate action. In some examples, the signal or alarm generated by supervisory layer 503 may also be characterized by a score, as further explained below. In other examples, supervisory layer 503 may be configured to aggregate information from historical events to further improve the robustness of predictions.

[0061] Figure 6 An example of a process box 502 is shown, which is used for a system that includes synchronous monitoring of all three pitch systems 32 of all three blades 22. For example... Figure 6 As shown, sensor data collected in box 501 from all three blades can be fed into residual calculation sub-box 504 within box 502. Sub-box 504 can be used for pairwise comparison of sensor data, i.e., sensor data from the pitch system of one blade can be compared individually with sensor data received for the other two blades. The comparison between sensor data from two of the blades can be used to generate residuals in sub-box 504, and these residuals can then be used to identify anomalous deviations in sub-box 505. As used herein, "residual" can be defined as the difference between the actual value and the predicted value for a variable. In this example, instead of using a model to obtain the predicted value, the signals from adjacent blades are treated as predictions or estimates. Therefore, the residual is calculated as the difference between the signal from one blade and the corresponding signal from the adjacent blade. In other examples, one or more models may be used to predict the value.

[0062] Sub-block 505 may include identifying outliers by, for example, comparing the received residuals to a threshold or by analyzing trends in the calculated residuals. As an example, the time evolution of the capacitance of the DC link of the electronic converter unit 75 may be measured. The residual signal can be calculated by subtracting the value measured for the adjacent blade from the capacitance value measured for one blade at each moment. The time evolution of the residuals provides an indication of how the two capacitances in the adjacent blade pitch system change over time. For example, if the difference between the two signals continues to increase, this may indicate that one of the two capacitors is damaged. Finally, the outliers identified in sub-block 505 may be combined in a final combination sub-block 506, which generates a signal for the subsequent supervision layer 503 based on all detected deviations.

[0063] In different examples, different time scales can be considered for collecting sensor data to monitor operating parameters. Monitoring strategies for data acquisition in the millisecond to second range can be used for rapidly occurring effects, while data acquisition in the day or even week range can be used for strategies aimed at detecting slow degradation of certain components.

[0064] More specifically, operating parameters can be monitored in real time while the wind turbine is in power generation mode. In this way, the rapid, localized effects of faults can be detected efficiently. This is particularly useful for predicting blade jamming events during power generation caused by certain faults, such as electrical faults in the electronic converter unit 75 or the pitch motor 74. Real-time monitoring while the wind turbine is in power generation mode can be performed in parallel with normal wind turbine operation, ensuring that the methods used to predict blade jamming events during power generation do not interfere with the standard operation of the wind turbine, thus maintaining the turbine's availability. Real-time monitoring can be considered as monitoring occurring during normal operation, i.e., without interruption of operation and without the need to create specific test scenarios.

[0065] In another example, operating parameters can be monitored using tests performed during wind turbine start-up and shutdown events and / or during maintenance operations. Using such tests can be particularly advantageous for detecting slow mechanisms that may cause blade jamming events during power generation. Such slow mechanisms may include mechanical degradation of the pitch bearing 72 and / or degradation of electrical components in the DC link 753 of the electronic converter unit 75.

[0066] As an example, the degradation of the pitch bearing 72 can be monitored by estimating the frictional force of the bearing. For this purpose, production data can be sampled periodically in batches. More specifically, pitch torque data can be sampled and analyzed to provide an estimate of the frictional force. This estimate can then be compared with an estimated frictional force for at least one other pitch system 32 corresponding to an adjacent blade.

[0067] Regarding the degradation of the DC link 753, the capacitor in the DC link 753 of the electronic converter unit 75 can be monitored by performing an equivalent series resistance (ESR) test. This test can be performed on different pitch systems 32 in the wind turbine during regular maintenance operations. An abnormal increase in ESR observed in one blade compared to other blades in the blade during regular testing can be an indicator of accelerated aging or impending failure of the corresponding capacitor. Alternatively, such ESR testing can also be performed continuously, i.e., during wind turbine operation.

[0068] Periodic testing can be synchronized with periodic preventative maintenance operations. In some examples, periodic testing can be automated, where certain operating parameters can be automatically monitored by collecting sensor data in automated self-test routines, and systems can be deployed to perform analysis of the received information.

[0069] In the examples disclosed herein, predicting the occurrence of a blade jamming event during power generation may include providing uncertainty in the prediction. A more robust system can be achieved by providing not only a prediction of the blade jamming event, but also the probability or uncertainty of the prediction itself. More specifically, according to Figure 5 The information sent from the supervisory layer 503 to the wind turbine controller 36 in the example may include not only alarms with predictions, but also scores characterizing the likelihood of achieving the predictions. The estimation of uncertainty may be based on various factors, such as the magnitude of the detected deviation (e.g., relative to a threshold), the specific operating parameter indicating the anomalous deviation, or the duration of a particular outlier. In cases of high uncertainty, unnecessary stringent preventative actions may be avoided, and less stringent actions may be substituted. In other variations, in cases of high uncertainty regarding prediction, actions may be delayed or suspended. Conversely, in cases where a highly deterministic prediction of a blade jamming event is obtained, stringent control actions may be performed.

[0070] In yet another example of this disclosure, predicting the occurrence of a blade jamming event during power generation may include providing an estimate of the remaining time before blade jamming. In this example, a more optimized response may be defined based on the anticipated event. Thus, in cases where a long period precedes the predicted blade jamming event, a response action that does not affect wind turbine operation may be advantageously selected. Conversely, in cases where the remaining time is short, an immediate response action (e.g., including but not limited to stopping the wind turbine) may be selected. The determination of the remaining time may be based on various factors, such as: the magnitude of the detected deviation (e.g., relative to a threshold), the specific operating parameter indicating the anomalous deviation, the duration of the specific outlier, or the expected operating conditions of the wind turbine (e.g., a shorter remaining time may be predicted if the wind turbine is expected to operate under high stress).

[0071] Upon receiving a prediction of a blade jamming event during power generation, different actions can be taken via the wind turbine controller 36. Furthermore, the actions themselves may depend on the uncertainties associated with the prediction and / or the urgency of the predicted event. In the examples of this disclosure, the method may simply involve generating an alarm. The alarm generated by the system may be received by a higher level of supervisory control (e.g., a wind farm-level SCADA system) or by an operator. Based on the alarm, different follow-up actions can be performed to address the predicted event.

[0072] In examples of this disclosure, the method may include changing the operating mode of the wind turbine to a new operating mode when a blade jamming event is predicted during power generation. To this end, the wind turbine controller 36 may be configured to automatically switch to the new operating mode upon receiving a signal from the supervisory layer 503. More specifically, the controller may be configured to actively adjust the operating mode based on a score of the signal received from the supervisory layer 503. This score may indicate the uncertainty of the prediction, the expected remaining time before the event occurs, etc.

[0073] Continuing with the previous example, in some variations, new operating modes for wind turbines may include derating operating modes. This is for cases where the score associated with the forecast is moderate. Therefore, by operating in derating mode, both the rotational speed and electrical torque can be reduced, thus alleviating some of the load. This reduction can help decrease the occurrence of blade jamming events.

[0074] In yet another example, which involves changing the mode of operation of a wind turbine, the operation can be changed to a shutdown mode designed to stop the wind turbine. This example constitutes a more extreme approach, where stopping the wind turbine can prevent blade jamming events during power generation. Clearly, stopping the wind turbine can be due to both technical and economic reasons rather than being desired; therefore, this approach can be used in situations involving predictions characterized by high scores, such as predictions that include both high certainty and high urgency of the event.

[0075] Figure 7 A flowchart illustrating an example of a method 100 for monitoring a wind turbine 10, the wind turbine 10 including a rotor 18 having a plurality of blades 22 and a pitch system 32 for each of the blades 22, the pitch system 32 being configured to rotate the corresponding blade 22 along its longitudinal axis. The method includes, at block 110, monitoring one or more operating parameters of a first pitch system and a second pitch system. Then, at block 120, the method includes predicting a blade jamming event for a first blade during power generation, based at least in part on the monitored operating parameters of the first and second pitch systems. Regarding block 110, the operating parameters to be monitored for the first and second pitch systems are predetermined in an analysis for a blade jamming event during power generation.

[0076] Therefore, by implementing according to Figure 7The methods described in the examples can predict blade jamming events before they actually occur. To do this, certain operating parameters are monitored, which are predetermined in an analysis for that specific event. Various types of analysis can be performed according to different examples of this disclosure. Thus, failure analysis based on studies of previously failed systems can be used. In other examples, simulations can be performed to assess the relevance of certain faults to blade jamming events and thus determine whether such faults should be monitored. As yet another example, literature-based analyses can also be performed to identify operating parameters that are particularly relevant to predicting blade jamming events during power generation.

[0077] Figure 8 A flowchart illustrating another example of a method 200 for monitoring a wind turbine 10, the wind turbine 10 including a rotor 18 having a plurality of blades 22 and a pitch system 32 for each of the blades 22, the pitch system 32 being configured to rotate the corresponding blade 22 along its longitudinal axis. Block 210 of method 200 includes monitoring one or more operating parameters of all pitch systems 32. The operating parameters to be monitored are predetermined in a failure mode and effects analysis (FMEA) to identify failure paths leading to blade jamming events during power generation. Then, in block 220, the method includes predicting a blade jamming event during power generation in one of the blades connected to one of the pitch systems, based at least in part on a comparison of the monitored operating parameters of all pitch systems.

[0078] Failure Mode and Effects Analysis (FMEA) is a systematic, step-by-step process used to examine components and subsystems to identify potential failure modes, their causes, and effects. A failure mode is a possible pattern or manner in which a system may fail. Failures are prioritized based on the severity of their impact or consequences, their frequency of occurrence, and their ease of detection. Failure modes and their effects on the system are identified and appropriately documented.

[0079] By using FMEA to determine operating parameters, a systematic approach can be taken to identify all faults that could lead to blade jamming events during power generation. Furthermore, FMEA allows for prioritizing faults based on their severity. In this example, data from all blades is used once the FMEA has been established. This approach is advantageous because it gathers more information from the system, and more importantly, by comparing operating parameters from multiple pitch systems, it makes it easier to identify anomalous deviations in a specific pitch system.

[0080] According to another aspect of this disclosure, a control system 36 for a wind turbine 10 is provided (see, for example...). Figure 5The control system 36 is configured to perform the method of monitoring a wind turbine as described throughout this disclosure or any equivalent example. Therefore, the control system 36 is configured to monitor one or more operating parameters of the first pitch system and the second pitch system, and, at least in part, predict a blade jamming event during power generation in one of the blades connected to the first or second pitch system, based on the monitored operating parameters of the first and second pitch systems. Furthermore, the operating parameters to be monitored for the first and second pitch systems are predetermined in the analysis of the event.

[0081] The control system can be embodied as a standalone controller, i.e., a controller designed solely to monitor the wind turbine 10 to predict the occurrence of blade jamming events during power generation, or it can be implemented in the pitch system controller 80 or the wind turbine controller 36.

[0082] This written description uses examples to disclose teachings and also enables any person skilled in the art to practice the teachings (including making and using any apparatus or system and performing any incorporated methods). The scope of patentability is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that are not different from the literal language of the claims, or if such other examples comprise equivalent structural elements that are not substantially different from the literal language of the claims. Aspects from the various examples described, and other known equivalents for each such aspect, may be mixed and matched by a person skilled in the art in accordance with the principles of this application to construct additional examples and techniques. If reference numerals relating to the drawings are placed within brackets in the claims, such reference numerals are merely intended to increase the comprehensibility of the claims and should not be construed as limiting the scope of the claims.

Claims

1. A method (100) for predicting blade jamming events during power generation in a wind turbine (10), the wind turbine (10) comprising a rotor (18) having a plurality of blades (22) and a pitch system (32) for each of the blades (22), the pitch system (32) being configured to rotate the corresponding blade (22) along its longitudinal axis, the method comprising: Monitor one or more operating parameters of the first pitch system (32) and the second pitch system (32); as well as Based at least in part on the operating parameters monitored by the first pitch system (32) and the operating parameters monitored by the second pitch system (32), a blade jamming event in one of the blades (22) connected to the first pitch system (32) or the second pitch system (32) during power generation is predicted. in The operating parameters to be monitored for the first pitch system (32) and the second pitch system (32) have been predetermined in the analysis of the event.

2. The method according to claim 1, wherein, Monitoring the operating parameters of at least the first pitch system (32) and the second pitch system (32) includes monitoring the operating parameters of all the pitch systems (32).

3. The method according to any one of claims 1 or 2, wherein, When the wind turbine (10) is in power generation mode, the operating parameters are monitored in real time.

4. The method according to any one of claims 1 or 2, wherein, The operating parameters are monitored using tests performed during the start-up and shutdown events of the wind turbine (10) and / or during maintenance operations.

5. The method according to any of the preceding claims, wherein, Each pitch system (32) includes a pitch bearing (72) that connects the blade (22) to the hub (20), a pitch driver (32) including a pitch motor (74), a pitch brake (77), a pitch gearbox (76), and a pinion (78).

6. The method according to claim 5, wherein, The operating parameters include at least one of the following: the torque of the pitch motor (74), the current of the pitch motor (74), the temperature of the pitch motor (74), or the vibration of the pitch motor (74).

7. The method according to any of the preceding claims, wherein, Each pitch system (32) includes an electronic converter unit (75) and the operating parameters include at least one of the voltage of the DC link (753), the current of the DC link (753), the output voltage, the input current, the capacitance of the DC link (753), or the temperature of the electronic converter unit (75).

8. The method according to any of the preceding claims, wherein, Predicting the occurrence of blade jamming events during power generation includes providing an indication of the uncertainty of the prediction.

9. The method according to any of the preceding claims, wherein, Predicting the occurrence of blade jamming events during power generation includes providing an estimate of the remaining time before the blade (22) jams.

10. The method according to any of the preceding claims, further comprising generating an alarm.

11. The method according to any of the preceding claims, the method further comprising changing the operating mode of the wind turbine (10) to a new operating mode of the wind turbine (10) when a blade jamming event is predicted during power generation.

12. The method according to claim 11, wherein, The new operating mode of the wind turbine (10) is the derated operating mode.

13. The method according to claim 11, wherein, The new operating mode of the wind turbine (10) is a stop operating mode designed to stop the wind turbine (10).

14. A control system (80) for a wind turbine (10), the wind turbine (10) comprising a rotor (18) having a plurality of blades (22) and a pitch system (32) for each of the blades (10), the pitch system (32) being configured to rotate the corresponding blade (22) along its longitudinal axis, and the control system being configured to: Monitor one or more operating parameters of the first pitch system (32) and the second pitch system (32); and Based at least in part on the monitored operating parameters of the first pitch system (32) and the monitored operating parameters of the second pitch system (32), a blade jamming event during power generation is predicted in one of the blades (22) connected to the first pitch system (32) or the second pitch system (32); wherein The operating parameters to be monitored for the first pitch system (32) and the second pitch system (32) have been predetermined in the analysis of the event.

15. A wind turbine (10) comprising the control system according to claim 14.

Images