Wind turbine generator, variable pitch bearing detection method, device and system, medium and product

Abstract

The invention discloses a wind turbine generator, a variable pitch bearing detection method, device and system, a medium and a product, and belongs to the technical field of wind power generation. The wind turbine generator comprises a first variable-pitch bearing and a first blade connected with the first variable-pitch bearing, and the method comprises the steps that the first actual driving voltage of the first variable-pitch bearing and the first actual rotating speed of the first blade in the feathering process are obtained; according to the conversion relation between the equivalent voltage and the driving voltage, the first actual driving voltage is converted into a first equivalent voltage at the reference rotation speed; and detecting whether the first variable pitch bearing is abnormal according to the first equivalent voltage to obtain a detection result. According to the method, the actual driving voltage of the variable-pitch bearing in the feathering process is obtained and converted into the equivalent voltage, so that whether the variable-pitch bearing is abnormal or not is detected according to the equivalent voltage, the driving voltage is collected in real time, the abnormality of the variable-pitch bearing can be detected in time, and the abnormality of the variable-pitch bearing can be found as early as possible, so that the abnormality detection accuracy of the variable-pitch bearing is improved.

Description

Technical Field

[0001] This application belongs to the field of wind power technology, specifically relating to a wind turbine generator, a method, device, system, computer-readable storage medium, and computer program product for testing pitch bearings. Background Technology

[0002] The pitch system is a critical safety system for wind turbine generators. One of its core functions is to drive the blades to a "feather" position of approximately 89 degrees when a shutdown is required. By changing the blade angle of attack, the aerodynamic capture efficiency is reduced, allowing the rotor to safely decelerate until it stops, acting as the main braking system of the generator set. The pitch bearing is the core load-bearing and rotating component of the pitch system. Its inner ring connects to the blade root, and its outer ring connects to the hub, bearing the enormous dynamic loads, gravity, and overturning moments from the blades.

[0003] Due to prolonged exposure to harsh operating conditions (such as alternating loads, vibration, dust, and temperature differences), pitch bearings are prone to mechanical failures such as wear, pitting, cracks, and even breakage. In the event of a serious failure, the blades may lose control of their attitude, leading to catastrophic accidents such as blades colliding with the tower or blades falling off, posing a significant threat to wind turbine safety and wind farm operation.

[0004] Currently, health monitoring of pitch bearings mainly relies on regular manual inspections and maintenance. This traditional method has significant drawbacks: First, it has a serious lag, making it impossible to provide timely warnings in the early stages or during the development of a fault; second, fault detection is accidental, and latent faults occurring during the inspection cycle cannot be detected in time; finally, as a purely mechanical component, the pitch bearing itself does not have electrical feedback function, making it difficult for conventional unit monitoring systems to directly perceive the gradual deterioration of its performance. Summary of the Invention

[0005] The purpose of this application is to provide a method, device, system, medium, and product for detecting wind turbine generator sets and pitch bearings, which can detect pitch bearing abnormalities as early as possible and improve the accuracy of pitch bearing abnormality detection.

[0006] In a first aspect, embodiments of this application provide a method for detecting the pitch bearing of a wind turbine. The wind turbine includes a first pitch bearing and a first blade connected to the first pitch bearing. The method includes: acquiring a first actual driving voltage of the first pitch bearing and a first actual rotational speed of the first blade during feathering; converting the first actual driving voltage to a first equivalent voltage at a reference rotational speed according to the conversion relationship between equivalent voltage and driving voltage; detecting whether the first pitch bearing is abnormal based on the first equivalent voltage, and obtaining a detection result.

[0007] Secondly, embodiments of this application provide a pitch bearing detection device for a wind turbine generator set. The wind turbine generator set includes a first pitch bearing and a first blade connected to the first pitch bearing. The device includes: an acquisition module for acquiring a first actual driving voltage of the first pitch bearing and a first actual rotational speed of the first blade during feathering; a conversion module for converting the first actual driving voltage to a first equivalent voltage at a reference rotational speed according to the conversion relationship between equivalent voltage and driving voltage; and a detection module for detecting whether the first pitch bearing is abnormal based on the first equivalent voltage and obtaining the detection result.

[0008] Thirdly, embodiments of this application provide a pitch system for a wind turbine, comprising: a main controller for outputting a feathering command; a pitch controller for generating a feathering control signal according to the feathering command; a servo driver for converting the feathering control signal into an electric drive signal to drive the pitch motor to rotate the pitch bearing; and detecting the drive voltage signal of the pitch bearing during rotation; and a pitch bearing detection device for the wind turbine, for executing the method of the first aspect.

[0009] Fourthly, embodiments of this application provide a wind turbine generator, including: a processor; a memory for storing computer program instructions; and when the computer program instructions are executed by the processor, the method as described in the first aspect is implemented.

[0010] Fifthly, embodiments of this application provide a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, implement the method as described in the first aspect.

[0011] In a sixth aspect, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the method as described in the first aspect.

[0012] In this embodiment of the application, when detecting pitch bearing anomalies, based on the principle that increased resistance and consequently increased drive voltage occur after a pitch bearing anomaly, the first actual drive voltage of the first pitch bearing and the first actual rotational speed of the first blade are first acquired during feathering. Then, since rotational speed is positively correlated with drive voltage, the first actual drive voltage is further converted to a first equivalent voltage at a reference rotational speed based on the conversion relationship between equivalent voltage and drive voltage. Finally, the first equivalent voltage is used to detect whether the first pitch bearing is abnormal, yielding the detection result. On the one hand, because the drive voltage signal is acquired in real-time during feathering, timely detection is possible, enabling early detection of pitch bearing anomalies and reducing lag and the sporadic nature of fault discovery. On the other hand, the equivalent voltage allows for accurate detection of pitch bearing anomalies, improving the precision of pitch bearing anomaly detection. Attached Figure Description

[0013] Figure 1 A schematic structural diagram of a pitch system of a wind turbine provided for some embodiments of the present application; Figure 2 A flowchart of a method for detecting a pitch bearing of a wind turbine provided for some embodiments of the present application; Figure 3 A trend chart of the change of voltage with time provided for some embodiments of the present application; Figure 4 A flowchart of S220 provided for some embodiments of the present application; Figure 5 A flowchart of detecting whether the first pitch bearing is abnormal provided for some embodiments of the present application; Figure 6 A flowchart of determining the change characteristics of the first equivalent voltage provided for some embodiments of the present application; Figure 7 A schematic structural diagram of a pitch bearing detection device of a wind turbine provided for some embodiments of the present application; Figure 8 A schematic structural diagram of an electronic device provided for some embodiments of the present application. Detailed implementation manners

[0014] Next, the technical solutions in the embodiments of the present application will be clearly described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope protected by the present application.

[0015] The terms "first", "second", etc. in the specification of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "and / or" in the specification means at least one of the connected objects, and the character "means" generally indicates that the related objects before and after are in an "or" relationship.

[0016] The pitch system is a critical safety system for wind turbine generators. One of its core functions is to drive the blades to a "feather" position of approximately 89 degrees when a shutdown is required. By changing the blade angle of attack, the aerodynamic capture efficiency is reduced, allowing the rotor to safely decelerate until it stops, acting as the main braking system of the generator set. The pitch bearing is the core load-bearing and rotating component of the pitch system. Its inner ring connects to the blade root, and its outer ring connects to the hub, bearing the enormous dynamic loads, gravity, and overturning moments from the blades.

[0017] Due to prolonged exposure to harsh operating conditions (such as alternating loads, vibration, dust, and temperature differences), pitch bearings are prone to mechanical failures such as wear, pitting, cracks, and even breakage. In the event of a serious failure, the blades may lose control of their attitude, leading to catastrophic accidents such as blades colliding with the tower or blades falling off, posing a significant threat to wind turbine safety and wind farm operation.

[0018] Currently, health monitoring of pitch bearings mainly relies on regular manual inspections and maintenance. This traditional method has significant drawbacks: 1) First, it has a serious lag, making it impossible to provide timely warnings in the early stages or during the development of a fault; 2) Secondly, fault discovery is accidental, and latent faults occurring during the inspection cycle cannot be detected in a timely manner. 3) Finally, as a purely mechanical component, the pitch bearing itself does not have electrical feedback function, and conventional unit monitoring systems can hardly directly perceive the gradual deterioration of its performance.

[0019] 4) Although bearing abnormalities can lead to increased rotational resistance, under sufficient motor driving torque, such resistance changes are usually insufficient to immediately trigger electrical faults such as system overload, thus allowing hidden dangers to remain latent for a long time until serious consequences occur.

[0020] To address the aforementioned issues, embodiments of this application provide a method, apparatus, system, computer-readable storage medium, and computer program product for detecting wind turbine generator sets and pitch bearings. These methods and devices can detect pitch bearing anomalies as early as possible, thereby improving the accuracy of pitch bearing anomaly detection.

[0021] The following is combined Figure 1 First, the pitch system of the wind turbine provided in the embodiments of this application will be described.

[0022] Before describing the pitch system of the wind turbine provided in the embodiments of this application, let’s first introduce the technical terms involved in the embodiments of this application.

[0023] Feathering: This refers to the action of rotating the blades of a wind turbine from their operating angle (usually small) to an extreme position of about 89 degrees. In this position, the blades have the least resistance to the wind, which slows down the wind turbine and is the main braking method of the unit.

[0024] Load: refers to the external forces acting on wind turbine components. For pitch bearings, these mainly include blade weight, aerodynamic thrust, centrifugal force, and inertial force, which together constitute a complex dynamic load.

[0025] Encoder: A sensor installed within the pitch system to accurately measure and provide feedback on the real-time rotation angle of the blades. Its signal is the basis for the pitch controller to achieve closed-loop control and for the timing calculations performed in this application.

[0026] Resistance: refers to the additional mechanical friction force that hinders the normal rotation of a pitch bearing due to internal faults (such as wear or cracks) or poor lubrication.

[0027] Frictional torque: refers to the torque generated by the internal resistance of the pitch bearing, which acts on the axis of rotation and opposes rotation. An increase in frictional torque will consume some of the motor's driving force, leading to a deterioration in the system's dynamic response.

[0028] Figure 1 This is a schematic diagram of the structure of a pitch system for a wind turbine provided in an embodiment of this application, as shown below. Figure 1 As shown, the pitch system 100 of the wind turbine may include a main controller 101, a pitch controller 102, a servo driver 103, a pitch motor 104, a gearbox 105, a pitch bearing 106, an encoder 107, and a data storage and analysis module 108.

[0029] The main controller 101, as the unit's overall control unit, outputs a feathering command (target position: 89°~90° feathering position) to the pitch controller 102 during normal shutdown or emergency fault shutdown, and at the same time receives an abnormal warning signal from the data storage and analysis module 108, triggering subsequent safety handling procedures.

[0030] The pitch controller 102 is used to generate a pitch control signal according to the pitch command and send the pitch control signal to the servo driver 103. The servo driver 103 is used to convert the pitch control signal into an electric drive signal to provide the pitch motor 104 with appropriate voltage and current to drive the pitch motor 104 to rotate the pitch bearing 106. On the other hand, the servo driver 103 detects the drive voltage signal of the pitch bearing 106 during rotation and uploads it synchronously to the data storage and analysis module 108.

[0031] It should be noted that the pitch bearing 106 is the core load-bearing and rotating component of the pitch system (the inner ring is connected to the blade root and the outer ring is connected to the hub), bearing dynamic loads such as blade gravity and aerodynamic thrust; its health condition (wear, pitting, cracks, etc.) directly affects the magnitude of the rotational resistance torque.

[0032] The pitch motor 104 receives the power drive signal from the servo driver 103, amplifies the torque through the gearbox 105, and drives the inner ring gear of the pitch bearing 106 to rotate, thereby causing the blades to rotate towards the feathering position. For example, the number of blades can be three.

[0033] The encoder 107 is used to measure the blade rotation angle in real time and feed it back to the pitch controller 102 (for closed-loop control), while uploading the angle data to the data storage and analysis module 108.

[0034] The data storage and analysis module 108 is used to comprehensively process the voltage signal from the servo driver 103 and the angle signal from the encoder 107, execute the status evaluation algorithm, and immediately send an early warning signal to the main controller 101 once an abnormality is detected, forming a complete monitoring closed loop.

[0035] The 89° proximity switch serves as a redundant confirmation signal for feathering position, assisting in verifying whether the blades have accurately reached the target position and ensuring the integrity of data acquisition (avoiding voltage data deviations due to failure to reach the target position).

[0036] During feathering operation, when the wind turbine receives a shutdown command (normal shutdown or emergency fault shutdown), the pitch controller 102 controls the three blades to independently rotate towards the 89° position at a preset speed curve. Simultaneously, it generates a feathering control signal containing the preset speed and target angle and sends it to the servo driver 103. The servo driver 103 converts the control signal into an electrical drive signal, driving the pitch motor 104 to rotate. Simultaneously, it monitors the drive voltage signal in real time and uploads it to the data storage and analysis module 108. The encoder 107 continuously monitors the blade angle change and feeds it back to the pitch controller 102, dynamically adjusting the control signal until the blades reach the target position (target position: 89°~90° feathering position). At this point, the pitch controller 102 sends a shutdown signal, the motor stops, and the brakes engage.

[0037] Based on the pitch system of the wind turbine described above, this application provides a method for detecting the pitch bearing of a wind turbine. The following is a detailed explanation... Figure 2 The present application provides a method for testing the pitch bearing of a wind turbine generator with specific embodiments.

[0038] Figure 2 This is a flowchart illustrating a method for detecting the pitch bearing of a wind turbine generator, provided as an embodiment of this application. This method can be applied to a data storage and analysis module. The wind turbine generator includes a first pitch bearing and a first blade connected to the first pitch bearing. Figure 2 As shown, the method for testing the pitch bearing of this wind turbine may include the following steps: S210. During the feathering process, the first actual driving voltage of the first pitch bearing and the first actual rotational speed of the first blade are obtained.

[0039] The first pitch bearing is the core load-bearing and rotating component in a wind turbine generator corresponding to the first blade. Internally, it connects to the root of the first blade, and externally, it connects to the hub, bearing the dynamic loads, gravity, and overturning moments transmitted by the blade. The first actual drive voltage V_angle is the real-time voltage signal output by the servo driver during feathering, used to drive the pitch motor corresponding to the first pitch bearing. The first actual rotational speed is the real-time speed V_set of the first blade rotating around its axis during feathering.

[0040] In practice, when the wind turbine receives a shutdown command and triggers feathering, the data acquisition program is initiated. The servo driver's voltage detection function is used to acquire its output drive voltage signal in real time; this signal is the first actual drive voltage, V_angle. Simultaneously, a blade angle encoder installed in the pitch system continuously acquires the real-time angle information of the first blade. Based on the ratio of the angle change at adjacent time points to the time interval, the first actual rotational speed, V_set, is calculated. The acquisition process continues until the first blade reaches the preset feathering position, ensuring complete data acquisition throughout the feathering process.

[0041] S220. Based on the conversion relationship between equivalent voltage and driving voltage, the first actual driving voltage is converted to the first equivalent voltage at the reference rotation speed.

[0042] The equivalent voltage V_std refers to the voltage value converted from the actual drive voltage under different operating conditions to a voltage value under a unified standard condition through a specific conversion rule, used to eliminate the influence of differences in operating conditions on the monitoring results. The reference rotation speed is a preset unified standard rotation speed. For example, in this embodiment, the reference rotation speed can be 2° / s, serving as the reference speed for voltage conversion. The conversion relationship is established based on the motor drive principle and the characteristics of the pitch system, used to implement the conversion logic from the actual drive voltage to the equivalent voltage under the reference rotation speed.

[0043] In practice, a reference rotational speed of 2° / s can be initially determined. A conversion relationship is established based on a speed conversion algorithm. The conversion formula is: equivalent voltage equals the actual driving voltage multiplied by the ratio of the reference rotational speed to the actual rotational speed, i.e., V_std = V_angle × (2.0 / V_set). Substituting the first actual driving voltage and the first actual rotational speed into this formula, the first equivalent voltage is calculated. This conversion eliminates the influence of differences in actual rotational speeds during different feathering processes, making voltage data under different operating conditions comparable and providing a unified benchmark for subsequent anomaly detection.

[0044] S230. Detect whether the first pitch bearing is abnormal based on the first equivalent voltage, and obtain the detection result.

[0045] The detection result refers to the determination, through analysis of the first equivalent voltage, of whether the first pitch bearing exhibits abnormal conditions such as wear, pitting, or cracks that lead to increased resistance. The result includes both normal and abnormal cases. Anomaly detection is the process of identifying the bearing's health status based on the correlation between pitch bearing anomalies and the equivalent voltage, using specific judgment logic.

[0046] In practice, historical equivalent voltage data of the first pitch bearing under healthy conditions can be retrieved first to establish a baseline curve. The currently obtained first equivalent voltage is then compared longitudinally with this baseline curve to analyze deviation trends. Simultaneously, the equivalent voltages of the other two pitch bearings corresponding to the same blades in the same unit during the same feathering process are obtained for lateral consistency comparison. By setting a reasonable deviation threshold, if the deviation of the first equivalent voltage from the historical baseline or from the other two equivalent voltages exceeds the threshold, the first pitch bearing is determined to be abnormal; otherwise, it is considered normal. By combining the longitudinal and lateral comparison results, a final detection result is generated, enabling accurate assessment of the bearing's condition.

[0047] It should be noted that when the pitch bearing exhibits abnormalities such as wear, pitting, or cracks, its internal frictional torque increases significantly. According to the motor drive principle, to maintain the set feathering speed, the driver needs to output a higher voltage to overcome the increased resistance torque. This physical relationship can be expressed as: V = Kω + IR + V_f Where V is the driver output voltage, ω is the motor speed, I is the armature current, R is the armature resistance, and V_f is the back electromotive force coefficient. When the bearing resistance increases, in order to maintain the same speed ω, the current I increases, which leads to an increase in voltage V.

[0048] Compared to parameters such as angle and speed, voltage is more sensitive to changes in resistance and can reflect abnormal bearing conditions earlier and more clearly. The voltage versus time trend graph is shown below. Figure 3 As shown. Therefore, this application establishes a correlation between the average output voltage of the drive during feathering and the pitch bearing resistance by converting it to a uniform speed condition. Increased resistance caused by bearing abnormalities will lead to a significant increase in the converted voltage, thereby achieving early fault diagnosis.

[0049] It should be noted that under normal circumstances, the feathering speed should remain basically constant (e.g., maintained at a preset 2° / s) because the pitch system will stabilize the speed by adjusting the drive voltage to ensure that the blades rotate smoothly to the feathering position. In this embodiment, the pitch bearing anomaly detection is based on the principle that increased resistance and consequently increased drive voltage occur after a pitch bearing anomaly, but the feathering speed will not change significantly. However, when the brake valve malfunctions, it will also cause increased rotational resistance during feathering. In this case, the servo drive will also increase the output voltage (consistent with the voltage behavior of a pitch bearing anomaly), but the speed will decrease significantly. This is because the resistance of the brake valve malfunction is continuously increasing (e.g., brake jamming gradually worsens), and even with increased voltage, it is difficult to maintain the original speed; the speed curve will show a "smaller and smaller arc" (gradually decreasing from the initial speed until the feathering action is affected). Therefore, in this embodiment, the speed remains basically constant from the start to the end of feathering, without a significant decrease.

[0050] In this embodiment of the application, when detecting pitch bearing anomalies, based on the principle that increased resistance and consequently increased drive voltage occur after a pitch bearing anomaly, the first actual drive voltage of the first pitch bearing and the first actual rotational speed of the first blade are first acquired during feathering. Then, since rotational speed is positively correlated with drive voltage, the first actual drive voltage is further converted to a first equivalent voltage at a reference rotational speed based on the conversion relationship between equivalent voltage and drive voltage. Finally, the first equivalent voltage is used to detect whether the first pitch bearing is abnormal, yielding the detection result. On the one hand, because the drive voltage signal is acquired in real-time during feathering, timely detection is possible, enabling early detection of pitch bearing anomalies and reducing lag and the sporadic nature of fault discovery. On the other hand, the equivalent voltage allows for accurate detection of pitch bearing anomalies, improving the precision of pitch bearing anomaly detection.

[0051] In this embodiment, when the blade rotates at a small angle, it is greatly affected by wind force, resulting in a large error. To avoid using small-angle sampling and reduce the error caused by wind force, as an example, S210 may include: acquiring the first actual driving voltage of the first pitch bearing and the first actual rotation speed of the first blade when the first blade rotates within a preset rotation angle range during feathering; the lower limit of the preset rotation angle range is greater than a preset angle threshold.

[0052] The first blade is the blade in the wind turbine generator that is connected to the first pitch bearing and rotates with the first pitch bearing to achieve feathering action. The preset rotation angle range is a range of blade rotation angles pre-set to ensure the effectiveness of data acquisition. The lower limit of the preset rotation angle range is greater than the preset angle threshold. The preset angle threshold is a critical angle determined based on load characteristics and is used to divide the angle range between load stability and fluctuation.

[0053] In practical implementation, a preset angle threshold can first be determined based on the characteristics of the wind turbine's pitch system and load distribution patterns. Typically, this is achieved by combining turbine operating data and simulation analysis to select an angle value that significantly reduces aerodynamic load. A preset rotation angle range is then set based on this threshold, ensuring that the lower limit of the range is greater than the preset angle threshold. When the turbine triggers feathering, the blades begin to rotate, and the system monitors the blade angle in real time. When the blades rotate to the lower limit of the preset rotation angle range, data acquisition is initiated. The first actual drive voltage is acquired through the voltage detection function of the servo driver, while the encoder obtains the blade angle data at each moment within the range. The first actual rotation speed is calculated by the ratio of the angle change to the time interval between adjacent moments. Data acquisition continues until the blades rotate to the upper limit of the preset rotation angle range, completing the data acquisition for that range.

[0054] It should be noted that during feathering, the aerodynamic and gravitational loads on the blades vary significantly across different angle ranges. In the low-angle range (close to the operating angle), the aerodynamic load on the blades is large, which can easily mask the drag changes in the pitch bearing caused by abnormalities, leading to interference with the voltage signal. Limiting the rotation angle range to a preset value greater than a preset angle threshold avoids the low-angle range where load fluctuations are severe, focusing data collection on the relatively stable mid-to-high-angle range. This reduces external load interference, allowing the actual drive voltage and actual rotation speed to more accurately reflect the drag state of the pitch bearing, thus improving the accuracy of subsequent anomaly detection.

[0055] As an example, such as Figure 4 As shown, S220 may include: S2201. Determine the first ratio between the reference rotational speed and the first actual rotational speed.

[0056] The reference rotational speed is a pre-set rotational speed used to standardize voltage conversion. It is the standard speed during normal operation of the pitch system. For example, in this embodiment, it can be 2° / s. The first actual rotational speed V_set is the real-time rotational speed of the first blade within a preset rotational angle range during feathering. The first ratio R is the ratio of the reference rotational speed 2° / s to the first actual rotational speed V_set, R = 2.0 / V_set, used to quantify the degree of influence of speed differences on the drive voltage.

[0057] S2202. Determine the first equivalent voltage at the reference rotation speed based on the product of the first actual driving voltage and the first ratio.

[0058] The first equivalent voltage V_std is the voltage value calculated by converting the first actual driving voltage V_angle to the reference rotation speed. It can eliminate the influence of speed difference and truly reflect the voltage state corresponding to the resistance of the pitch bearing.

[0059] For example, V_std = V_angle × (2.0 / V_set).

[0060] By calculating the first ratio between the reference rotational speed and the first actual rotational speed, and then multiplying the first actual driving voltage by this ratio, the first equivalent voltage at the reference rotational speed is obtained. This approach simplifies and simplifies the conversion process, effectively eliminating the influence of different actual rotational speeds on the driving voltage during feathering. This ensures that voltage data acquired under different operating conditions have a unified and comparable benchmark. Regardless of whether the actual rotational speed changes due to differences in shutdown scenarios, fluctuations in unit operating status, or other factors, this conversion logic can standardize the driving voltage to the preset reference rotational speed dimension. This ensures that the first equivalent voltage accurately reflects the true resistance state of the first pitch bearing, preventing speed differences from masking potential bearing anomalies or causing misjudgments. It provides accurate and reliable basic data support for subsequent anomaly detection, significantly improving the consistency and accuracy of pitch bearing condition monitoring.

[0061] In this embodiment, the wind turbine also includes a second pitch bearing and a second blade connected to the second pitch bearing. The second blade is any blade in the wind turbine except for the first blade, and has the same structure and operating environment as the first blade. Its corresponding pitch bearing has the same specifications and model as the first pitch bearing, and they both participate in the feathering action.

[0062] To more accurately determine whether the first pitch bearing is malfunctioning, in this embodiment, the first blade can be compared laterally with other blades in the same unit to determine whether the first pitch bearing is malfunctioning. Specifically, during feathering, the second actual driving voltage of the second pitch bearing and the second actual rotational speed of the second blade can be obtained; based on the conversion relationship between equivalent voltage and driving voltage, the second actual driving voltage is converted to the second equivalent voltage at the reference rotational speed.

[0063] For example, the second pitch bearing is another core load-bearing rotating component in the wind turbine unit with the same structure and specifications as the first pitch bearing. It is connected to the root of the second blade and bears the load transmitted by the second blade. The second blade is a blade in the same unit that operates in conjunction with the first blade, and its rotation drives the second pitch bearing. The second actual drive voltage is a real-time voltage signal output by the servo driver during feathering, used to drive the pitch motor corresponding to the second pitch bearing. The second actual rotation speed is the real-time speed of the second blade rotating around its axis during feathering. It should be noted that the acquisition methods for the second actual drive voltage and the second actual rotation speed of the second blade are the same as those for the first actual drive voltage and the first actual rotation speed of the first blade, and will not be described in detail here.

[0064] After obtaining the second actual driving voltage of the second pitch bearing and the second actual rotational speed of the second blade, the second actual driving voltage is further converted to the second equivalent voltage at the reference rotational speed using the same voltage conversion method.

[0065] As an example, the detection of whether the first pitch bearing is abnormal based on the first equivalent voltage and the detection result can include: determining whether the first pitch bearing is abnormal based on the relative magnitude of the first equivalent voltage and the second equivalent voltage, and obtaining the detection result.

[0066] The relative magnitude relationship refers to the degree of numerical difference between the first equivalent voltage and the second equivalent voltage, and is used to quantify the deviation between the two.

[0067] By synchronously acquiring the second actual driving voltage of the second pitch bearing and the second actual rotational speed of the second blade in the same wind turbine unit, and obtaining the second equivalent voltage through the same conversion logic as the first equivalent voltage, and then determining the state of the first pitch bearing based on the relative magnitude of the two, this method can leverage the common advantages of consistent specifications, similar operating environment, and load characteristics among the pitch bearings in the same unit to construct a cross-bearing lateral comparison benchmark. This effectively eliminates interference from common environmental conditions such as wind speed and temperature. Compared to monitoring methods that rely solely on their own data, this method can more accurately capture abnormal voltage deviations of the first pitch bearing, avoiding misjudgments or missed judgments caused by deviations in individual historical data or fluctuations in single operating conditions. This significantly improves the reliability and sensitivity of anomaly detection. At the same time, the unified voltage conversion standard ensures the validity of the comparison data, providing a more comprehensive and reliable basis for pitch bearing state monitoring.

[0068] As an example, such as Figure 5 As shown, when determining whether the first pitch bearing is abnormal based on the relative magnitude of the first equivalent voltage and the second equivalent voltage, and obtaining the detection result, the following may be included: S510. Determine the difference between the first equivalent voltage and the second equivalent voltage.

[0069] The first equivalent voltage accurately reflects the voltage state corresponding to the resistance of the first pitch bearing. The second equivalent voltage is the voltage value calculated by applying the same reference rotational speed to the actual drive voltage of other pitch bearings (such as the second pitch bearing) in the same wind turbine generator set that have different blades than the first pitch bearing. This second equivalent voltage serves as the comparison benchmark for the first equivalent voltage. The difference between the first and second equivalent voltages quantifies the degree of deviation between them.

[0070] S520. Determine whether the difference is greater than the preset difference. If the difference is greater than the preset difference, execute S530. If the difference is less than or equal to the preset difference, execute S540.

[0071] The preset difference is a critical value determined based on the design parameters of the wind turbine pitch system, operating experience, and the voltage fluctuation range under healthy conditions of the pitch bearing. It is used as a criterion for judging whether the pitch bearing is abnormal. Abnormality refers to problems such as wear, pitting, cracks, or poor lubrication in the pitch bearing, which leads to increased rotational resistance and causes the equivalent voltage to deviate from the normal range.

[0072] S530, The first pitch bearing is found to be faulty.

[0073] In practice, a pre-set difference value can be retrieved. This value is determined through extensive unit measurement data, simulation analysis, and engineering practice verification to ensure accurate differentiation between normal fluctuations and abnormal deviations. The difference value is then compared with the preset difference value. If the difference value is greater than the preset difference value, it indicates that the equivalent voltage of the first pitch bearing deviates too much from the second equivalent voltage used as a reference, indirectly reflecting that the rotational resistance of the first pitch bearing is significantly greater than normal. Therefore, the first pitch bearing is determined to be abnormal.

[0074] S540, Confirm that the first pitch bearing is normal.

[0075] For example, "normal" means that the pitch bearing has no obvious wear, pitting, cracks or other faults, is in good lubrication condition, has rotational resistance within the normal range allowed by design, and its corresponding equivalent voltage deviates from the reference equivalent voltage within a reasonable range.

[0076] In practice, the difference is compared with a preset difference. If the difference is less than or equal to the preset difference, it indicates that the deviation between the first and second equivalent voltages is within the normal fluctuation range. This means that the rotational resistance of the first pitch bearing has not increased abnormally, and its operating condition meets the design requirements. Therefore, the first pitch bearing is determined to be normal. Simultaneously, the current first equivalent voltage data can be updated to the historical benchmark database to provide a more accurate comparison basis for subsequent monitoring.

[0077] By calculating the difference between the first and second equivalent voltages and using a preset difference as the judgment threshold, the standard for classifying the first pitch bearing as normal or abnormal is clearly defined. This transforms cross-bearing voltage comparisons into intuitive and quantitative numerical judgments, simplifying the logical process of anomaly detection. The preset difference is determined based on the voltage fluctuation patterns of pitch bearings operating normally within the same unit, accurately distinguishing between normal fluctuations and abnormal deviations. This avoids misjudging faults due to minor voltage differences and prevents significant anomalies from being missed. This quantitative judgment method improves the objectivity and consistency of detection results, allowing for rapid conclusions without complex trend analysis. Furthermore, relying on horizontal comparisons within the same unit effectively eliminates common interferences, further enhancing the accuracy and reliability of anomaly detection. This provides simple yet powerful technical support for timely early warning and efficient operation and maintenance of pitch bearings.

[0078] In this embodiment of the application, there are multiple second blades, and correspondingly, there are also multiple second equivalent voltages. Based on the relative magnitude relationship between the first equivalent voltage and the second equivalent voltage, it is determined whether the first pitch bearing is abnormal and a detection result is obtained. The method may also include: determining the average voltage of multiple second equivalent voltages; and based on the relative magnitude relationship between the first equivalent voltage and the average voltage, determining whether the first pitch bearing is abnormal and a detection result is obtained.

[0079] For example, the average voltage is the value obtained by arithmetically averaging multiple second equivalent voltages, which can comprehensively reflect the normal voltage level of multiple second pitch bearings and reduce the impact of accidental fluctuations of a single second equivalent voltage on the test results.

[0080] When determining whether the first pitch bearing is abnormal based on the relative magnitude of the first equivalent voltage and the average voltage, the detection results can be obtained by first acquiring the difference between the first equivalent voltage and the average voltage, and then comparing this difference with a preset deviation threshold. If the difference is greater than the deviation threshold, it indicates that the equivalent voltage of the first pitch bearing deviates significantly from the average voltage level of multiple second pitch bearings, indirectly reflecting an abnormal increase in the rotational resistance of the first pitch bearing, thus determining that the first pitch bearing is abnormal. If the difference is less than or equal to the deviation threshold, it indicates that the first equivalent voltage is within the normal fluctuation range, and the rotational resistance of the first pitch bearing is not abnormal, thus determining that the first pitch bearing is normal. At the same time, the first equivalent voltage and the average voltage are updated to the historical benchmark database to provide a more accurate comparison basis for subsequent monitoring.

[0081] By calculating the average voltage of multiple second equivalent voltages and using this average as a unified comparison benchmark, the normal operating voltage characteristics of multiple second pitch bearings in the same unit can be comprehensively utilized. This effectively offsets the interference caused by occasional fluctuations or minor individual differences in a single second equivalent voltage, making the comparison benchmark more closely match the normal voltage level of the unit. Compared to the comparison method using a single second equivalent voltage, the average voltage is more representative and stable, significantly reducing the risk of misjudgment caused by temporary fluctuations in the operating conditions of a single component. At the same time, through the comprehensive quantification of multiple data samples, the abnormal voltage deviation characteristics of the first pitch bearing are further amplified, improving the sensitivity to identify minor anomalies. This ensures the objectivity and reliability of the detection results and enhances the adaptability of the method to complex operating scenarios, providing a more accurate and robust judgment basis for pitch bearing anomaly detection.

[0082] To further improve the accuracy of anomaly detection in the first pitch bearing, this embodiment of the application can also perform a longitudinal comparison between the characteristics of the first pitch bearing and historical time periods. Specifically, the reference equivalent voltage sequence of the first pitch bearing within the target historical time period can be obtained first.

[0083] For example, the reference equivalent voltage sequence includes the drive voltage of the first pitch bearing at different historical moments when the first pitch bearing is in normal condition. This drive voltage is a set of voltage data formed after being converted by reference rotation speed and angle, and is a voltage reference dataset reflecting the normal operating state of the bearing. The target historical period is a historical period within a preset time length corresponding to the current moment of the feathering process. This time length is determined based on the unit's operating rules and the bearing failure development cycle to ensure that the data can reflect the recent normal state.

[0084] In practical implementation, a preset duration for the target historical period can be set first. Combining the operating frequency of the wind turbine generator and the failure evolution cycle of the pitch bearing, a period within the recent few months is typically selected to ensure the timeliness and reference value of the data. For example, all feathering process data corresponding to the first pitch bearing within the target historical period can be filtered from the system's historical database, and it must be confirmed that the bearing operating status corresponding to these data is normal (no fault records, and maintenance records confirm normal operation). For the drive voltage of each filtered historical feathering process, velocity conversion is performed sequentially using the same conversion method as the current feathering process to obtain the reference equivalent voltage corresponding to each historical moment. All reference equivalent voltages are arranged in chronological order to form a reference equivalent voltage sequence.

[0085] After obtaining the reference equivalent voltage sequence, the reference equivalent voltage variation characteristics of the first pitch bearing are further determined based on each reference equivalent voltage in the reference equivalent voltage sequence.

[0086] For example, the reference equivalent voltage variation characteristics refer to the variation law and fluctuation characteristics of voltage data over time in the reference equivalent voltage sequence, including core characteristics such as the average voltage level, fluctuation amplitude, and variation trend, which are used to define the range and law of voltage variation under normal conditions.

[0087] In practice, the acquired benchmark equivalent voltage sequence can be retrieved, and statistical analysis can be performed on all benchmark equivalent voltages in the sequence. The arithmetic mean of the sequence is calculated to determine the average voltage level under normal conditions; the standard deviation of the voltage data is calculated to quantify the normal fluctuation range; and linear fitting or trend analysis algorithms are used to determine whether the voltage change trend over time is stable, slowly increasing, or slowly decreasing. By combining the average level, fluctuation range, and trend, the benchmark equivalent voltage change characteristics are formed, clarifying the voltage change pattern of the first pitch bearing under normal conditions.

[0088] For example, when detecting whether the first pitch bearing is abnormal based on the first equivalent voltage and obtaining the detection result, specifically, the variation characteristics of the first equivalent voltage can be determined based on the first equivalent voltage and the reference equivalent voltage in the target historical period; based on the variation characteristics of the reference equivalent voltage and the variation characteristics of the first equivalent voltage, the first pitch bearing is detected to be abnormal and the detection result is obtained.

[0089] The variation characteristics of the first equivalent voltage refer to the deviation and trend of the first equivalent voltage obtained during the current feathering process relative to the reference equivalent voltage sequence, including the deviation value from the average level of the reference and the degree of deviation from the reference fluctuation range.

[0090] In practice, the current first equivalent voltage and reference equivalent voltage sequences can be retrieved, and the difference between the arithmetic mean of the first equivalent voltage and the reference equivalent voltage sequences can be calculated to determine the magnitude of the absolute deviation. The fluctuation ranges of the first equivalent voltage and the reference equivalent voltage sequences can be compared to determine whether they are within the normal fluctuation range. Combining the time-varying trend of the reference equivalent voltage, the direction and magnitude of the change in the first equivalent voltage relative to the recent reference voltage can be analyzed, and this information can be used to determine the variation characteristics of the first equivalent voltage.

[0091] Then, the current voltage change characteristics are compared with the reference voltage change characteristics under normal conditions to determine whether the deviation between the two exceeds a reasonable range, thereby determining whether the bearing has a fault.

[0092] In practice, the variation characteristics of the first equivalent voltage can be comprehensively compared with those of the reference equivalent voltage. If the deviation of the first equivalent voltage from the average level of the reference exceeds a reasonable multiple of the reference fluctuation amplitude, or if its variation trend is opposite to the reference trend and the amplitude is significant, it indicates that the current voltage change deviates from the normal pattern, indirectly reflecting an abnormal increase in bearing rotation resistance, and the first pitch bearing is determined to be abnormal. If the variation characteristics of the first equivalent voltage are within the reasonable range defined by the reference equivalent voltage variation characteristics, it indicates that the bearing resistance is not abnormal, and the first pitch bearing is determined to be normal. After the test is completed, the first equivalent voltage is updated to the historical database for subsequent dynamic updates of the reference equivalent voltage sequence.

[0093] As an example, such as Figure 6 As shown, the variation characteristics of the first equivalent voltage are determined based on the first equivalent voltage and the reference equivalent voltage at the target historical time, which may include: S610: Obtain the historical average temperature for the target historical period and the current temperature during the feathering process.

[0094] Exemplarily, the historical average temperature in the target historical period refers to the average temperature of the operating environment of the pitch bearing within the target historical period, which is used to reflect the temperature background during historical monitoring. The current temperature is the real-time temperature of the operating environment of the pitch bearing when the feathering process occurs.

[0095] During specific implementation, all temperature record data within the target historical period can be retrieved from the system environment monitoring database, and these data are subjected to arithmetic average operation to obtain the historical average temperature. The ambient temperature when the feathering process occurs is collected in real time through the temperature sensor supporting the pitch system, which is the current temperature. Ensure that the collection locations of the historical temperature data and the current temperature data are the same, both being the ambient temperature near the pitch bearing, to ensure the comparability of the data.

[0096] S620. Calculate the temperature difference between the historical average temperature and the current temperature.

[0097] The temperature difference is the numerical difference between the historical average temperature and the current temperature, which is used to quantify the degree of temperature change.

[0098] S630. Determine whether the temperature difference is greater than the preset temperature difference. If the temperature difference is greater than the preset temperature difference, execute S640; if the temperature difference is not greater than the preset temperature difference, execute S660.

[0099] Exemplarily, the magnitude of the preset temperature difference is determined according to the relationship between the lubricating oil viscosity and temperature in the first pitch bearing; the lubricating oil viscosity is the viscosity of the lubricating oil itself, and its magnitude changes with temperature, thereby affecting the rotational resistance and drive voltage of the pitch bearing. The change range of the lubricating oil viscosity within the preset temperature difference is less than the preset range.

[0100] It should be noted that temperature affects the viscosity of the lubricating oil, and different viscosities result in different drive pressures. Therefore, when the temperature difference is large, the viscosity change is also relatively large. To ensure accuracy, temperature compensation is required to convert it to the reference temperature for comparison, thereby reducing the influence of viscosity change caused by temperature change on the drive voltage change.

[0101] S640. Based on the relationship between temperature, the lubricating oil viscosity in the pitch bearing, and the drive voltage, convert the first equivalent voltage and the reference equivalent voltage within the target historical period to the first equivalent voltage and the reference equivalent voltage at the reference temperature respectively.

[0102] In practice, firstly, based on the type and characteristics of the lubricating oil in the pitch bearing, the relationship curve between the lubricating oil viscosity and temperature is determined. A preset range is then set based on this curve to ensure that the change in lubricating oil viscosity within the preset temperature difference does not exceed this range, thus determining the specific value of the preset temperature difference. The calculated temperature difference is compared with the preset temperature difference. If the temperature difference is greater than the preset temperature difference, it indicates that the temperature change has a significant impact on the lubricating oil viscosity, requiring temperature correction. Based on a pre-established correlation model between temperature, lubricating oil viscosity, and driving voltage, the first equivalent voltage and the reference equivalent voltage within the target historical period are substituted into the model to complete the voltage conversion to the reference temperature, eliminating the influence of temperature differences.

[0103] S650. Determine the variation characteristics of the first equivalent voltage based on the first equivalent voltage at the reference temperature and the reference equivalent voltage.

[0104] In practice, the first equivalent voltage and the reference equivalent voltage at the reference temperature can be retrieved, and the difference between them can be calculated and analyzed. Combining this with the historical variation patterns of the reference equivalent voltage, the direction and extent of deviation of the first equivalent voltage from the reference voltage at the reference temperature can be determined. By comprehensively considering the magnitude of the difference and the direction of deviation, the variation characteristics of the first equivalent voltage can be clarified, providing an accurate basis for subsequent abnormal detection of the pitch bearing.

[0105] S660 eliminates the need for temperature conversion between the first equivalent voltage and the reference equivalent voltage within the target historical period.

[0106] When the temperature difference is not greater than the preset temperature difference, the change in lubricating oil viscosity is within the preset range. This change has a negligible impact on the drive voltage and will not interfere with the voltage data's reflection of the true resistance state of the pitch bearing. Therefore, no additional temperature correction is required to ensure the accuracy of subsequent anomaly detection.

[0107] By acquiring the average historical temperature of the target period and the current temperature and calculating the temperature difference, when the temperature difference exceeds a preset value, the first equivalent voltage and the reference equivalent voltage are uniformly converted to the reference temperature based on the correlation between temperature, lubricating oil viscosity, and drive voltage. The change characteristics of the first equivalent voltage are then determined accordingly, effectively eliminating the influence of temperature changes on lubricating oil viscosity and thus eliminating drive voltage interference caused by viscosity fluctuations. The preset temperature difference is determined based on the relationship between lubricating oil viscosity and temperature, ensuring the targeted and reasonable nature of temperature correction. Voltage standardization at the reference temperature makes the benchmark for longitudinal comparison more consistent, avoiding misjudgments of bearing condition due to temperature differences. This significantly improves the accuracy and reliability of longitudinal monitoring based on historical data, making the identification of progressive bearing degradation trends more accurate and providing more rigorous data support for early fault warning and predictive maintenance.

[0108] In order to promptly notify maintenance personnel when the first pitch bearing malfunctions, in this embodiment of the application, a warning signal is sent to the main controller of the pitch system when the detection result indicates that the first pitch bearing is malfunctioning.

[0109] The warning signal is used to inform the main controller of the pitch system that there is an abnormality in the first pitch bearing. It includes key information such as the type of abnormality, detection data, and the time of occurrence, providing a basis for subsequent handling. The main controller is the core control unit of the pitch system, responsible for receiving signals from various modules, coordinating system operation, responding to abnormal warnings, and triggering corresponding handling procedures. The detection result is a conclusion drawn from the equivalent voltage analysis and comparison described above, determining whether the first pitch bearing is normal or abnormal.

[0110] In practice, the system first continuously monitors the final detection results of the aforementioned anomaly detection process. When the detection result indicates an anomaly in the first pitch bearing, the early warning signal generation program is immediately initiated. Based on the relevant data collected and processed during the detection process, an early warning signal containing specific information is generated. This requires clearly defining the criteria for determining the anomaly of the first pitch bearing, including the first equivalent voltage value, its deviation from the reference equivalent voltage or other blade equivalent voltages, relevant temperature and speed parameters, etc., to ensure the central controller has a comprehensive understanding of the anomaly.

[0111] Simultaneously, in accordance with the preset signal transmission protocol and interface specifications of the pitch system, the generated warning signal is sent to the main controller of the pitch system. After receiving the warning signal, the main controller can perform corresponding operations according to preset strategies, such as issuing maintenance notifications, adjusting the unit's operating status, or activating emergency safety measures, to respond promptly to abnormal situations and prevent the fault from escalating. At the same time, the system records the warning event and related data to a historical database, including the time of the anomaly, detection data, and warning signal content, providing data support for subsequent fault investigation, maintenance analysis, and system optimization.

[0112] Upon detecting an anomaly in the first pitch bearing, a timely warning signal is sent to the pitch system's main controller, establishing a complete closed loop of "detection-early warning-response." The warning signal quickly triggers the main controller's subsequent handling procedures, enabling maintenance personnel or the system to be aware of the bearing's abnormal condition immediately. This prevents the anomaly from escalating and causing catastrophic accidents such as blade runaway or collisions, significantly improving the operational safety of the wind turbine. Simultaneously, timely warnings allow sufficient time for fault diagnosis and repair, reducing unplanned downtime, lowering maintenance costs and economic losses, and transforming reactive maintenance into proactive intervention. This provides crucial support for efficient pitch bearing maintenance and stable turbine operation.

[0113] In this embodiment of the application, when detecting pitch bearing anomalies, based on the principle that increased resistance and consequently increased drive voltage occur after a pitch bearing anomaly, the first actual drive voltage of the first pitch bearing and the first actual rotational speed of the first blade are first acquired during feathering. Then, since rotational speed is positively correlated with drive voltage, the first actual drive voltage is further converted to a first equivalent voltage at a reference rotational speed based on the conversion relationship between equivalent voltage and drive voltage. Finally, the first equivalent voltage is used to detect whether the first pitch bearing is abnormal, yielding the detection result. On the one hand, because the drive voltage signal is acquired in real-time during feathering, timely detection is possible, enabling early detection of pitch bearing anomalies and reducing lag and the sporadic nature of fault discovery. On the other hand, the equivalent voltage allows for accurate detection of pitch bearing anomalies, improving the precision of pitch bearing anomaly detection.

[0114] In addition, pitch bearing anomaly detection is achieved using the drive voltage signal of the pitch bearing, which can be provided by the servo drive in the wind turbine, thus avoiding the possibility that conventional unit monitoring systems cannot directly perceive the gradual degradation of its performance.

[0115] Based on the same inventive concept, this application also provides a pitch bearing testing device for wind turbine units, which will be described below. Figure 7 The pitch bearing testing device for wind turbine units provided in the embodiments of this application will be described in detail.

[0116] Figure 7 This is a schematic diagram of the structure of a pitch bearing testing device for a wind turbine provided in an embodiment of this application.

[0117] like Figure 7 As shown, the pitch bearing testing device 700 of the wind turbine may include: The acquisition module 701 is used to acquire the first actual driving voltage of the first pitch bearing and the first actual rotational speed of the first blade during the feathering process. The conversion module 702 is used to convert the first actual driving voltage to the first equivalent voltage at the reference rotation speed according to the conversion relationship between the equivalent voltage and the driving voltage. The detection module 703 is used to detect whether the first pitch bearing is abnormal based on the first equivalent voltage and obtain the detection result.

[0118] In this embodiment of the application, when detecting pitch bearing anomalies, based on the principle that increased resistance and consequently increased drive voltage occur after a pitch bearing anomaly, the first actual drive voltage of the first pitch bearing and the first actual rotational speed of the first blade are first acquired during feathering. Then, since rotational speed is positively correlated with drive voltage, the first actual drive voltage is further converted to a first equivalent voltage at a reference rotational speed based on the conversion relationship between equivalent voltage and drive voltage. Finally, the first equivalent voltage is used to detect whether the first pitch bearing is abnormal, yielding the detection result. On the one hand, because the drive voltage signal is acquired in real-time during feathering, timely detection is possible, enabling early detection of pitch bearing anomalies and reducing lag and the sporadic nature of fault discovery. On the other hand, the equivalent voltage allows for accurate detection of pitch bearing anomalies, improving the precision of pitch bearing anomaly detection.

[0119] In some possible implementations of the embodiments of this application, the acquisition module 701 is specifically used for: During the feathering process, when the first blade rotates within a preset rotation angle range, the first actual driving voltage of the first pitch bearing and the first actual rotation speed of the first blade are obtained. The lower limit of the preset rotation angle range is greater than the preset angle threshold.

[0120] In some possible implementations of the embodiments of this application, the conversion module 702 is specifically used for: Determine a first ratio between the reference rotational speed and the first actual rotational speed; The first equivalent voltage at the reference rotational speed is determined by multiplying the first actual driving voltage by the first ratio.

[0121] In some possible implementations of the embodiments of this application, the wind turbine also includes a second pitch bearing and a second blade connected to the second pitch bearing; The acquisition module 701 is also used for: During the feathering process, the second actual driving voltage of the second pitch bearing and the second actual rotational speed of the second blade are obtained. Based on the conversion relationship between equivalent voltage and driving voltage, the second actual driving voltage is converted to the second equivalent voltage at the reference rotation speed; The detection module 703 is specifically used for: Based on the relative magnitudes of the first and second equivalent voltages, the detection results are obtained to determine whether the first pitch bearing is abnormal.

[0122] In some possible implementations of the embodiments of this application, the detection module 703 is specifically used for: Determine the difference between the first equivalent voltage and the second equivalent voltage; If the difference is greater than the preset difference, the first pitch bearing is determined to be abnormal; If the difference is less than or equal to the preset difference, the first pitch bearing is determined to be normal.

[0123] In some possible implementations of the embodiments of this application, there are multiple second blades, and correspondingly, there are also multiple second equivalent voltages. The detection module 703 is specifically used for: Determine the average voltage of multiple second equivalent voltages; Based on the relative magnitudes of the first equivalent voltage and the average voltage, the detection results are obtained to determine whether the first pitch bearing is abnormal.

[0124] In some possible implementations of the embodiments of this application, the acquisition module 701 is further configured to: Obtain the reference equivalent voltage sequence of the first pitch bearing within the target historical period; the reference equivalent voltage sequence includes the driving voltage of the first pitch bearing at different historical moments when the first pitch bearing is in a normal state; the target historical period is the historical period within a preset time length from the current moment corresponding to the feathering process; Based on each reference equivalent voltage in the reference equivalent voltage sequence, the reference equivalent voltage variation characteristics of the first pitch bearing are determined. The detection module 703 is specifically used for: The variation characteristics of the first equivalent voltage are determined based on the first equivalent voltage and the reference equivalent voltage during the target historical period. Based on the variation characteristics of the reference equivalent voltage and the variation characteristics of the first equivalent voltage, the abnormality of the first pitch bearing is detected, and the detection results are obtained.

[0125] In some possible implementations of the embodiments of this application, the detection module 703 is specifically used for: Obtain the historical average temperature for the target historical period and the current temperature during the feathering process; Calculate the temperature difference between the historical average temperature and the current temperature; When the temperature difference is greater than the preset temperature difference, based on the relationship between temperature, lubricating oil viscosity in the pitch bearing and driving voltage, the first equivalent voltage and the reference equivalent voltage in the target historical period are converted to the first equivalent voltage and the reference equivalent voltage at the reference temperature, respectively; the magnitude of the preset temperature difference is determined according to the relationship between the lubricating oil viscosity in the first pitch bearing and temperature; the change range of lubricating oil viscosity at the preset temperature difference is less than the preset range. The variation characteristics of the first equivalent voltage are determined based on the first equivalent voltage at the reference temperature and the reference equivalent voltage.

[0126] In some possible implementations of the embodiments of this application, the pitch bearing detection device 700 for wind turbine units further includes: a transmitting module; The sending module is used to: send a warning signal to the main controller of the pitch system in response to the detection result that the first pitch bearing is abnormal.

[0127] The pitch bearing testing device for wind turbines provided in this application embodiment can achieve… Figures 2 to 6 The various processes in the embodiment of the method for detecting the pitch bearing of a wind turbine are the same and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0128] Based on the same inventive concept, this application also provides a wind turbine generator, such as... Figure 8 As shown, the wind turbine 800 may include a processor 801 and a memory 802 for storing computer program instructions.

[0129] Processor 801 may include a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or one or more integrated circuits that may be configured to implement the embodiments of this application.

[0130] Memory 802 may include mass storage for data or instructions. For example, and not limitingly, memory 802 may include a hard disk drive (HDD), a floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. In one instance, memory 802 may include removable or non-removable (or fixed) media, or memory 802 may be non-volatile solid-state memory. In one instance, memory 802 may be read-only memory (ROM). In one instance, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these.

[0131] The processor 801 reads and executes computer program instructions stored in the memory 802 to achieve... Figures 2-6 The method in the illustrated embodiment achieves... Figures 2-6 The corresponding technical effects achieved by the methods in the illustrated embodiments are described briefly and will not be elaborated further here.

[0132] In one example, the wind turbine 800 may also include a communication interface 803 and a bus 804. For example, Figure 8As shown, the processor 801, memory 802, and communication interface 803 are connected through bus 804 and complete communication with each other.

[0133] The communication interface 803 is mainly used to realize communication between various modules, devices and / or equipment in the embodiments of this application.

[0134] Bus 804 includes hardware, software, or both, that couples the components of wind turbine 800 together. For example, and not as a limitation, bus 804 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 804 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0135] Furthermore, in conjunction with the wind turbine pitch bearing detection method in the above embodiments, this application embodiment can provide a computer storage medium for implementation. This computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the wind turbine pitch bearing detection methods in the above embodiments.

[0136] Furthermore, in conjunction with the wind turbine pitch bearing detection method in the above embodiments, this application embodiment can provide a computer program product to implement it. This computer program product includes a computer program that, when executed by a processor, implements any of the wind turbine pitch bearing detection methods in the above embodiments.

[0137] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for testing the pitch bearing of a wind turbine generator set, characterized in that, The wind turbine includes a first pitch bearing and a first blade connected to the first pitch bearing; the method includes: During the feathering process, the first actual driving voltage of the first pitch bearing and the first actual rotational speed of the first blade are obtained. Based on the conversion relationship between equivalent voltage and driving voltage, the first actual driving voltage is converted to the first equivalent voltage at the reference rotation speed; The first pitch bearing is checked for abnormality based on the first equivalent voltage, and the detection result is obtained.

2. The method according to claim 1, characterized in that, The process of obtaining the feathering data includes the first actual driving voltage of the first pitch bearing and the first actual rotational speed of the first blade. During the feathering process, when the first blade rotates within a preset rotation angle range, the first actual driving voltage of the first pitch bearing and the first actual rotation speed of the first blade are obtained. The lower limit of the preset rotation angle range is greater than the preset angle threshold.

3. The method according to claim 1, characterized in that, The step of converting the first actual driving voltage to the first equivalent voltage at the reference rotation speed based on the conversion relationship between the equivalent voltage and the driving voltage includes: Determine a first ratio between the reference rotational speed and the first actual rotational speed; The first equivalent voltage at the reference rotational speed is determined based on the product of the first actual driving voltage and the first ratio.

4. The method according to any one of claims 1-3, characterized in that, The wind turbine also includes a second pitch bearing and a second blade connected to the second pitch bearing. The method further includes: During the feathering process, the second actual driving voltage of the second pitch bearing and the second actual rotational speed of the second blade are obtained; Based on the conversion relationship between equivalent voltage and driving voltage, the second actual driving voltage is converted to the second equivalent voltage at the reference rotation speed; The step of detecting whether the first pitch bearing is abnormal based on the first equivalent voltage and obtaining the detection result includes: Based on the relative magnitudes of the first equivalent voltage and the second equivalent voltage, it is determined whether the first pitch bearing is abnormal, and the detection results are obtained.

5. The method according to claim 4, characterized in that, The step of determining whether the first pitch bearing is abnormal based on the relative magnitudes of the first equivalent voltage and the second equivalent voltage, and obtaining the detection result, includes: Determine the difference between the first equivalent voltage and the second equivalent voltage; If the difference is greater than a preset difference, the first pitch bearing is determined to be abnormal. If the difference is less than or equal to a preset difference, the first pitch bearing is determined to be normal.

6. The method according to claim 4 or 5, characterized in that, There are multiple second blades, and correspondingly, there are also multiple second equivalent voltages. The step of determining whether the first pitch bearing is abnormal based on the relative magnitudes of the first and second equivalent voltages, and obtaining the detection results, includes: Determine the average voltage of multiple second equivalent voltages; Based on the relative magnitudes of the first equivalent voltage and the average voltage, the detection result is obtained to determine whether the first pitch bearing is abnormal.

7. The method according to any one of claims 1-3, characterized in that, The method further includes: Obtain the reference equivalent voltage sequence of the first pitch bearing within a target historical period; the reference equivalent voltage sequence includes the drive voltage of the first pitch bearing at different historical moments when the first pitch bearing is in a normal state; the target historical period is a historical period within a preset time interval from the current moment corresponding to the feathering process; Based on each reference equivalent voltage in the reference equivalent voltage sequence, the reference equivalent voltage variation characteristics of the first pitch bearing are determined. The step of detecting whether the first pitch bearing is abnormal based on the first equivalent voltage and obtaining the detection result includes: Based on the first equivalent voltage and the reference equivalent voltage within the target historical period, the variation characteristics of the first equivalent voltage are determined; Based on the variation characteristics of the reference equivalent voltage and the variation characteristics of the first equivalent voltage, the abnormality of the first pitch bearing is detected, and the detection result is obtained.

8. The method according to claim 7, characterized in that, The step of determining the variation characteristics of the first equivalent voltage based on the first equivalent voltage and the reference equivalent voltage at the target historical time includes: Obtain the historical average temperature for the target historical period and the current temperature during the feathering process; Calculate the temperature difference between the historical average temperature and the current temperature; When the temperature difference is greater than the preset temperature difference, based on the relationship between temperature, lubricating oil viscosity in the pitch bearing and driving voltage, the first equivalent voltage and the reference equivalent voltage in the target historical period are respectively converted to the first equivalent voltage and the reference equivalent voltage at the reference temperature; the magnitude of the preset temperature difference is determined according to the relationship between the lubricating oil viscosity in the first pitch bearing and temperature; the change range of the lubricating oil viscosity at the preset temperature difference is less than the preset range. The variation characteristics of the first equivalent voltage are determined based on the first equivalent voltage at the reference temperature and the reference equivalent voltage.

9. The method according to any one of claims 1-3, characterized in that, The method further includes: In response to the detection result indicating an abnormality in the first pitch bearing, a warning signal is sent to the main controller of the pitch system.

10. A testing device for the pitch bearing of a wind turbine, characterized in that, The wind turbine includes a first pitch bearing and a first blade connected to the first pitch bearing; the device includes: The acquisition module is used to acquire the first actual driving voltage of the first pitch bearing and the first actual rotational speed of the first blade during the feathering process. The conversion module is used to convert the first actual driving voltage to the first equivalent voltage at the reference rotation speed according to the conversion relationship between the equivalent voltage and the driving voltage. The detection module is used to detect whether the first pitch bearing is abnormal based on the first equivalent voltage and obtain the detection result.

11. A pitch control system for a wind turbine generator, characterized in that, include: The main controller is used to output feathering commands; A pitch controller is used to generate a feathering control signal according to the feathering command; Servo driver; The device is used to convert the feathering control signal into an electric drive signal to drive the pitch motor to rotate the pitch bearing; and to detect the drive voltage signal of the pitch bearing during rotation. A pitch bearing testing device for wind turbine units, used to perform the method according to any one of claims 1-9.

12. A wind turbine generator set, characterized in that, include: processor; Memory is used to store computer program instructions; When the computer program instructions are executed by the processor, the method as described in any one of claims 1-9 is implemented.

13. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the computer program instructions are executed by the processor, the method as described in any one of claims 1-9 is implemented.

14. A computer program product, characterized in that, It includes a computer program, which, when executed by a processor, implements the method as described in any one of claims 1-9.

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