Methods and systems for monitoring bolt fracture in wind turbine units

Abstract

This application provides a method and system for monitoring bolt fracture in wind turbine generators. The system includes at least one proximity sensor installed on the wind turbine generator. The method includes: acquiring in real-time a status signal generated by the proximity sensor and a rotation angle signal reflecting the relative rotational movement of a monitored flange; wherein the monitored flange connects two components with relative rotational movement; the status signal indicates whether a bolt has passed near the proximity sensor; based on the rotation angle signal and a known bolt distribution pattern, determining the expected position range of the target bolt corresponding to the current rotation angle signal; and comparing the acquired status signal with the expected position range. This application can monitor bolt fracture in real-time and control the continuous operation of the wind turbine generator.

Description

Technical Field

[0001] This application relates to the technical field of wind power equipment monitoring, specifically to a method and system for monitoring bolt fracture in wind turbine units. Background Technology

[0002] In wind turbines, flange bolts are used to connect rotating components such as blades to the hub and nacelle to the tower. Over long periods of operation, fatigue damage or extreme conditions can cause bolts to break, posing a significant risk to the operational safety of the wind turbine. Regular maintenance cannot detect these problems promptly; monitoring using wind turbine operating data and sensor equipment is necessary to identify bolt breakage issues in a timely manner.

[0003] Existing technologies address the above issues by using non-contact sensor pulse signal detection to calculate the location and number of broken bolts at the blade root, or by real-time monitoring of bolt pressure to identify bolt failure. However, these methods lack real-time monitoring of bolt breakage and control over the unit's continuous operating status, leading to the unit operating with defects and further exacerbating the fault condition.

[0004] Therefore, there is an urgent need for a control scheme that can monitor bolt breakage in real time and the continuous operating status of the unit. Summary of the Invention

[0005] This application proposes a method and system for monitoring bolt fracture in wind turbine units, which addresses the deficiencies of the prior art.

[0006] According to a first aspect of the embodiments of this application, a method for monitoring bolt fracture in a wind turbine is provided, applied to a wind turbine bolt fracture monitoring system, the wind turbine bolt fracture monitoring system including at least one proximity sensor installed on the wind turbine, the method comprising: The system acquires in real time the status signal generated by the proximity sensor and the rotation angle signal reflecting the relative rotational motion of the monitored flange; wherein the monitored flange is used to connect two components with relative rotational motion, and the connecting bolts are arranged at equal intervals around the circumference; the status signal is used to indicate whether there are bolts passing around the proximity sensor. Based on the rotation angle signal and the known bolt distribution pattern, the expected position range of the target bolt corresponding to the rotation angle signal at the current moment is determined; wherein, the expected position range refers to the angle range within which the target bolt should be detectable under normal circumstances; The real-time acquired status signal is compared with the expected position range; wherein, when the current angle of the rotation angle signal is within the expected position range of the target bolt and the status signal indicates that there are no bolts around it, the target bolt is determined to be broken; otherwise, the target bolt is determined to be in normal condition.

[0007] In some embodiments, before acquiring the status signal generated by the proximity sensor and the rotation angle signal reflecting the relative rotational motion of the monitored flange in real time, the method further includes: Obtain the total number N of bolts arranged at equal intervals around the circumference of the monitored flange; The spacing angle θ between adjacent bolts is calculated based on the total number N, where θ = 360° / N; Set a reference bolt and record its reference angle to determine the theoretical angular position of all bolts.

[0008] In some implementations, determining the expected position range of the target bolt corresponding to the rotation angle signal at the current moment, based on the rotation angle signal and the known bolt distribution pattern, includes: The expected position range is determined based on the theoretical angular position of the target bolt, the physical width δ of the target bolt, and the preset allowable deviation coefficient α.

[0009] In some embodiments, the expected position interval is characterized by being an angular range with a width of (1-α)δ centered on the theoretical angular position of the target bolt.

[0010] In some embodiments, the method further includes: Obtain the maximum rotation angle β of the monitored component of the wind turbine; The minimum number M of proximity sensors required to be installed is calculated based on the maximum rotation angle β, where M is the smallest integer not less than (360° / β). M proximity sensors are evenly distributed on a circumference concentric with the distribution circle of the bolt holes of the flange being monitored.

[0011] In some implementations, determining that the target bolt has broken when the current angle of the rotation angle signal is within the expected position range of the target bolt and the status signal indicates that there are no bolts in the vicinity includes: The corresponding expected location interval is marked as the first interval, and the state signal within the first interval is expected to indicate the presence of a bolt. The gap between the theoretical angular positions of adjacent bolts and far from the expected position interval is marked as the second interval. Within the second interval, the state signal is expected to indicate a bolt-free state. When a signal indicating no bolt is detected within the angle range of the first interval, the determination that the target bolt has broken is triggered.

[0012] In some implementations, after determining that the target bolt has broken, the following steps are included: Generate shutdown control commands and send them to the main control system of the wind turbine to request the unit to perform a safe shutdown operation; A fault alarm signal containing information about the broken bolt is generated and sent to the remote monitoring system.

[0013] According to a second aspect of this application, a wind turbine bolt fracture monitoring system is provided for implementing the method described above, the system comprising: The sensing module includes at least one proximity sensor configured to be mounted on a component that moves relative to the flange being monitored, for generating a status signal indicating whether a bolt has passed around the perimeter of the proximity sensor; the connecting bolts of the flange being monitored are arranged at equal intervals around the circumference. The signal acquisition module is configured to acquire in real time the status signal generated by the sensing module, and to acquire the rotation angle signal reflecting the relative rotational motion of the monitored flange from the wind turbine control system. The processing and analysis module is configured to determine the expected position range of the target bolt at the current moment based on the rotation angle signal and the known bolt distribution pattern; and to compare and correlate the real-time acquired state signal with the expected position range to generate a state determination result of the target bolt. The communication control module is configured to send the status determination result of the target bolt to the associated component.

[0014] In some embodiments, the communication control module is further configured to: after receiving the status determination result of the target bolt, generate a shutdown control command and send it to the main control system of the wind turbine, and generate a fault alarm signal and send it to the remote monitoring system.

[0015] In some implementations, the monitored flange is the pitch system flange, yaw system flange, or main shaft connection flange of the wind turbine.

[0016] The beneficial effects of the wind turbine bolt fracture monitoring method and system of this application embodiment include at least the following: This application embodiment achieves non-contact, continuous monitoring of bolt status by acquiring real-time status signals generated by proximity sensors and rotation angle signals reflecting the relative rotational motion of the monitored flange. This method avoids the structural complexity and high cost associated with installing detection elements on the bolts, resulting in a simple system structure, high reliability, and ease of implementation on existing wind turbine units. Secondly, based on the rotation angle signals and the predicted bolt distribution patterns, the expected position range of the target bolt is determined, transforming the physical spatial positional relationship into a calculable angle range judgment standard. This method makes the monitoring process data-driven, improving the accuracy and intelligence of status judgment and laying a theoretical foundation for subsequent precise comparison. Finally, by correlating and comparing the real-time status signals with the expected position range and making a judgment based on specific logic (if there is an angle signal within the range but no bolt status signal, it is judged as a crack), automatic, real-time diagnosis of bolt fracture faults is achieved. This judgment logic is clear and reliable, effectively distinguishing between normal and abnormal fracture states, thus providing a core decision-making basis for timely issuance of shutdown commands and alarm information, avoiding the risk of the unit operating with defects. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the wind turbine bolt fracture monitoring method according to an embodiment of this application. Figure 2 The present application discloses a top view schematic diagram of an exemplary embodiment of the wind turbine bolt fracture monitoring method of the present application, showing the distribution of sensors and bolts. Figure 3 This is a schematic diagram illustrating the change of the proximity sensor status signal with position (or time) according to an embodiment of this application. Figure 4 This is a flowchart of a specific embodiment of the wind turbine bolt fracture monitoring method of this application. Figure 5 This is a schematic diagram of the structure of the wind turbine bolt fracture monitoring system according to an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the wind turbine bolt fracture monitoring method and system will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of this application. Obviously, the described embodiments are only some embodiments of the embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed embodiments of the present application, but merely to illustrate selected embodiments of the present application. Other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are all within the scope of protection of the embodiments of the present application.

[0020] It can be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it will not be further defined and explained in subsequent figures according to the embodiments of this application.

[0021] This application discloses a method for monitoring bolt fracture in wind turbine generators. This method is applied to a wind turbine generator bolt fracture monitoring system, which includes at least one proximity sensor installed on the wind turbine generator. The purpose is to monitor the fracture of bolts arranged circumferentially at equal intervals using flanges, which are subject to rotational motion in the wind turbine generator. It also aims to detect fractures in real time and control the turbine generator to shut down, preventing the generator from operating with defects and further deterioration of the fault condition. The method includes steps 110-150.

[0022] Step 110: Real-time acquisition of the status signal generated by the proximity sensor and the rotation angle signal reflecting the relative rotational motion of the monitored flange.

[0023] The monitored flange is used to connect two components that have relative rotational motion, and the connecting bolts are arranged at equal intervals around the circumference; the status signal is used to indicate whether there are bolts passing around the proximity sensor.

[0024] In addition, the location of the flange to be monitored is determined based on the bolt breakage condition, and the following conditions must be met: there is rotational movement between the two components, the bolts are installed in an equally spaced circumferential arrangement when using flange connection, and the rotation angle is measurable in real time.

[0025] In some embodiments, before acquiring the status signal generated by the proximity sensor and the rotation angle signal reflecting the relative rotational motion of the monitored flange in real time, the method further includes: acquiring the total number N of bolts arranged at equal intervals around the circumference of the monitored flange; calculating the interval angle θ between adjacent bolts based on the total number N, where θ = 360° / N; setting a reference bolt and recording the reference angle of the reference bolt to determine the theoretical angular position of all bolts.

[0026] In some embodiments, the method further includes: obtaining the maximum rotation angle β of the monitored component of the wind turbine; calculating the minimum number M of proximity sensors required to be installed based on the maximum rotation angle β, where M is a minimum integer not less than (360° / β); and evenly distributing the M proximity sensors on a circumference concentric with the bolt hole distribution circle of the monitored flange.

[0027] See attached document Figure 2 The diagram shown is a top view of an exemplary embodiment of the sensor and bolt distribution in the wind turbine bolt fracture monitoring method of this application. Figure 2 As shown, N bolts (represented by a nut graphic) are evenly distributed on the circumference of the monitored flange (or similar rotating component). At least two proximity sensors (rectangular blocks) are evenly installed along a circumference concentric with the bolt distribution circle. Figure 2 The key angle parameters are indicated in the diagram: the spacing angle θ between adjacent bolts, and the angle of the i-th bolt relative to the reference point. and the angle between the j-th sensor and the reference direction. The arrows indicate the relative rotation direction of the components, clearly demonstrating the spatial and geometric relationships of each bolt detected sequentially by the sensor during rotation. Figure 2 In this system, the bolts are distributed at equal intervals around the circumference and are subject to rotational motion.

[0028] See attached document Figure 3 The diagram illustrates how the status signal of a proximity sensor changes with position (or time). Figure 3 Plotting position / time on the horizontal axis and sensor state value η on the vertical axis, the signal is high when the sensor detects a bolt (η=1), corresponding to the shaded area in the figure; when the sensor is in the gap between bolts (η=0), the signal is low, corresponding to the blank area in the figure. This figure visually illustrates the ideal waveform of the sensor output signal, providing a clear basis for determining whether a bolt exists (i.e., whether the signal is high within the expected position range).

[0029] For example, if a bolt (i.e., a reference bolt) is marked with serial number 1 and its corresponding angle is 0, and the serial numbers are increased clockwise, then the 1st bolt... The angle corresponding to each bolt is: A proximity sensor is installed on a component that has relative motion with the bolt to detect the maximum rotation angle of the rotational motion. When the angle is less than 360 degrees, this embodiment of the application uses multiple proximity sensors, where the number of sensors M is 360 divided by the maximum rotation angle. Round down and add 1, then distribute the values ​​evenly around the circumference. Mark a proximity sensor as 1. When it is directly in front of bolt number 1, the rotation angle is... The value is 0, and the sequence number increases clockwise, indicating the rotation angle of the j-th proximity sensor. The proximity sensor state η is either 0 or 1, and it is determined when there is a bolt in front of the j-th proximity sensor. On the contrary .

[0030] Step 120: Based on the rotation angle signal and the known bolt distribution pattern, determine the expected position range of the target bolt corresponding to the rotation angle signal at the current moment.

[0031] The expected position range refers to the angular range within which the target bolt should be detectable under normal circumstances.

[0032] It is understandable that bolts have a certain width. Assuming that a single bolt occupies an angle of δ, and considering that bolt sizes may vary and measurement errors are taken into account, an allowable deviation coefficient α less than 1 needs to be set.

[0033] In some implementations, determining the expected position range of the target bolt corresponding to the rotation angle signal at the current moment based on the rotation angle signal and the known bolt distribution pattern includes: determining the expected position range based on the theoretical angular position of the target bolt, the physical width δ of the target bolt, and a preset allowable deviation coefficient α.

[0034] For example, the expected position range is an angular range with a width of (1-α)δ centered on the theoretical angular position of the target bolt.

[0035] Step 130: The real-time acquired status signal is correlated and compared with the expected location range.

[0036] Specifically, if the current angle of the rotation angle signal is within the expected position range of the target bolt, and the status signal indicates that there are no bolts around it, then the target bolt is determined to be broken; otherwise, the target bolt is determined to be in normal condition.

[0037] In some implementations, determining that the target bolt has broken when the current angle of the rotation angle signal is within the expected position range of the target bolt and the status signal indicates that there are no bolts around it includes: marking a first interval corresponding to the expected position range, in which the status signal is expected to indicate that there are bolts; marking a second interval corresponding to the gap between the theoretical angle positions of adjacent bolts and far from the expected position range, in which the status signal is expected to indicate that there are no bolts; and triggering the determination that the target bolt has broken when a status signal indicating that there are no bolts is detected within the angle range belonging to the first interval.

[0038] In some implementations, after determining that the target bolt has broken, the process includes: generating a shutdown control command and sending it to the main control system of the wind turbine to request the turbine to perform a safe shutdown operation; generating a fault alarm signal containing information identifying the broken bolt and sending it to a remote monitoring system.

[0039] Figure 4 A flowchart of a specific embodiment of the wind turbine bolt fracture monitoring method according to this application is disclosed. For example... Figure 4 As shown, this method begins with the initialization and setting of system parameters, followed by a cyclic monitoring process: real-time acquisition of proximity sensor status and rotation angle signals; first, it determines whether the angle is within interval I where a bolt should be detected; if so, it further verifies whether the sensor status is "1" (i.e., a bolt is present); if the verification fails, it determines that the bolt is broken and triggers a shutdown and alarm; if the angle is not within interval I, it continues to determine whether it is within interval II corresponding to the bolt gap, and verifies whether the sensor status is "0" (i.e., no bolt). Through this multi-interval, state-based progressive judgment logic, continuous and accurate monitoring and fault handling of the bolt status are achieved.

[0040] For example, regarding the first There are n bolts. When the j-th proximity sensor rotates relative to bolt number 1 by an angle of 1... Time: in interval I (i.e., the first interval), that is , It is in interval II (i.e., the second interval), that is , ; in other intervals III, state It can be 0 or 1. The above is the rotation angle under normal circumstances. Proximity sensor status The relationship, when the first One bolt broke, and the rotation angle met the requirements. hour, Therefore, it can be determined based on the rotation angle. Proximity sensor status Determine the bolt breakage status. When the system detects the bolt breakage... When a bolt breaks, a shutdown request is sent to the unit control system, and a unit bolt breakage fault warning is sent to the wind farm centralized control data acquisition and monitoring control system (SCADA), requiring the wind farm to carry out maintenance.

[0041] This application embodiment achieves non-contact, continuous monitoring of bolt status by acquiring real-time status signals generated by proximity sensors and rotation angle signals reflecting the relative rotational motion of the monitored flange. This method avoids the structural complexity and high cost associated with installing detection elements on the bolts, resulting in a simple system structure, high reliability, and ease of implementation on existing wind turbine units. Secondly, based on the rotation angle signals and the predicted bolt distribution patterns, the expected position range of the target bolt is determined, transforming the physical spatial positional relationship into a calculable angle range judgment standard. This method makes the monitoring process data-driven, improving the accuracy and intelligence of status judgment and laying a theoretical foundation for subsequent precise comparison. Finally, by correlating and comparing the real-time status signals with the expected position range and making a judgment based on specific logic (if there is an angle signal within the range but no bolt status signal, it is judged as a crack), automatic, real-time diagnosis of bolt fracture faults is achieved. This judgment logic is clear and reliable, effectively distinguishing between normal and abnormal fracture states, thus providing a core decision-making basis for timely issuance of shutdown commands and alarm information, avoiding the risk of the unit operating with defects.

[0042] This embodiment of the application installs proximity sensors on the flanges requiring monitoring to collect the unit's motion status and sensor pulse signals. The pulse signals are analyzed to determine if any abnormalities exist, thus identifying whether bolt breakage has occurred. Based on the contactless nature of the proximity sensors, the system is low-cost, simple, and reliable. This solution is versatile and can be applied to bolt monitoring of rotating components in wind turbines, such as pitch flange bolts, yaw flange bolts, and main shaft flange bolts. By connecting to the wind turbine control system, bolt breakage can be monitored in real time, and shutdown commands can be issued promptly to prevent further deterioration due to malfunctions.

[0043] This application also discloses a wind turbine bolt fracture monitoring system for implementing the above method. The system includes: a sensing module signal 510, an acquisition module 520, a processing and analysis module 530, and a communication control module 540.

[0044] The sensing module 510 includes at least one proximity sensor configured to be mounted on a component that has relative motion with respect to the flange being monitored, for generating a status signal indicating whether bolts have passed around the proximity sensor; the connecting bolts of the flange being monitored are arranged at equal intervals around the circumference.

[0045] The signal acquisition module 520 is configured to acquire in real time the status signal generated by the sensing module, and to acquire the rotation angle signal reflecting the relative rotational motion of the monitored flange from the wind turbine control system.

[0046] The processing and analysis module 530 is configured to determine the expected position range of the target bolt at the current moment based on the rotation angle signal and the known bolt distribution pattern; and to compare and correlate the real-time acquired state signal with the expected position range to generate the state judgment result of the target bolt.

[0047] The communication control module 540 is configured to send the status determination result of the target bolt to the associated component.

[0048] In some implementations, the communication control module 540 is further configured to: after receiving the status determination result of the target bolt, generate a shutdown control command and send it to the main control system of the wind turbine, and generate a fault alarm signal and send it to the remote monitoring system.

[0049] In some implementations, the monitored flange is the pitch system flange, yaw system flange, or main shaft connection flange of the wind turbine.

[0050] The wind turbine bolt fracture monitoring system disclosed in this application achieves non-contact signal acquisition through a sensing module, laying the hardware foundation for the system's low cost and high reliability. With the collaborative work of the signal acquisition and processing analysis modules, physical signals are transformed into intelligently judgeable state results, realizing the automation and intelligence of the monitoring process. Finally, the communication control module ensures that the judgment results can be reported in real time, thus forming a complete monitoring solution with modular construction, clear functions, and reliable operation.

[0051] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of this application, and this application is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this application, and these modifications and improvements are also considered to be within the scope of protection of this application.

Claims

1. A method for monitoring bolt fracture in wind turbine units, characterized in that, A method for monitoring bolt fracture in a wind turbine generator set includes at least one proximity sensor mounted on the wind turbine generator set. The system acquires in real time the status signal generated by the proximity sensor and the rotation angle signal reflecting the relative rotational motion of the monitored flange; wherein the monitored flange is used to connect two components with relative rotational motion, and the connecting bolts are arranged at equal intervals around the circumference; the status signal is used to indicate whether there are bolts passing around the proximity sensor. Based on the rotation angle signal and the known bolt distribution pattern, the expected position range of the target bolt corresponding to the rotation angle signal at the current moment is determined; wherein, the expected position range refers to the angle range within which the target bolt should be detectable under normal circumstances; The real-time acquired status signal is compared with the expected position range; wherein, when the current angle of the rotation angle signal is within the expected position range of the target bolt and the status signal indicates that there are no bolts around it, the target bolt is determined to be broken; otherwise, the target bolt is determined to be in normal condition.

2. The method according to claim 1, characterized in that, Before acquiring the status signal generated by the proximity sensor and the rotation angle signal reflecting the relative rotational motion of the monitored flange in real time, the method further includes: Obtain the total number N of bolts arranged at equal intervals around the circumference of the monitored flange; The spacing angle θ between adjacent bolts is calculated based on the total number N, where θ = 360° / N; Set a reference bolt and record its reference angle to determine the theoretical angular position of all bolts.

3. The method according to claim 1, characterized in that, The step of determining the expected position range of the target bolt corresponding to the rotation angle signal at the current moment, based on the rotation angle signal and the known bolt distribution pattern, includes: The expected position range is determined based on the theoretical angular position of the target bolt, the physical width δ of the target bolt, and the preset allowable deviation coefficient α.

4. The method according to claim 3, characterized in that, The expected position range is an angular range with a width of (1-α)δ, centered on the theoretical angular position of the target bolt.

5. The method according to claim 1, characterized in that, The method further includes: Obtain the maximum rotation angle β of the monitored component of the wind turbine; The minimum number M of proximity sensors required to be installed is calculated based on the maximum rotation angle β, where M is the smallest integer not less than (360° / β). M proximity sensors are evenly distributed on a circumference concentric with the distribution circle of the bolt holes of the flange being monitored.

6. The method according to claim 3 or 4, characterized in that, The step of determining that the target bolt has broken when the current angle of the rotation angle signal is within the expected position range of the target bolt and the status signal indicates that there are no bolts around it includes: The corresponding expected location interval is marked as the first interval, and the state signal within the first interval is expected to indicate the presence of a bolt. The gap between the theoretical angular positions of adjacent bolts and far from the expected position interval is marked as the second interval. Within the second interval, the state signal is expected to indicate a bolt-free state. When a signal indicating no bolt is detected within the angle range of the first interval, the determination that the target bolt has broken is triggered.

7. The method according to claim 1, characterized in that, After determining that the target bolt has broken, the following steps are included: Generate shutdown control commands and send them to the main control system of the wind turbine to request the unit to perform a safe shutdown operation; A fault alarm signal containing information about the broken bolt is generated and sent to the remote monitoring system.

8. A wind turbine bolt fracture monitoring system, characterized in that, include: The sensing module includes at least one proximity sensor configured to be mounted on a component that moves relative to the flange being monitored, for generating a status signal indicating whether a bolt has passed around the perimeter of the proximity sensor; the connecting bolts of the flange being monitored are arranged at equal intervals around the circumference. The signal acquisition module is configured to acquire in real time the status signal generated by the sensing module, and to acquire the rotation angle signal reflecting the relative rotational motion of the monitored flange from the wind turbine control system. The processing and analysis module is configured to determine the expected position range of the target bolt at the current moment based on the rotation angle signal and the known bolt distribution pattern; and to compare and correlate the real-time acquired state signal with the expected position range to generate a state determination result of the target bolt. The communication control module is configured to send the status determination result of the target bolt to the associated component.

9. A wind turbine bolt fracture monitoring system according to claim 8, characterized in that, The communication control module is further configured to: after receiving the status determination result of the target bolt, generate a shutdown control command and send it to the main control system of the wind turbine, and generate a fault alarm signal and send it to the remote monitoring system.

10. A wind turbine bolt fracture monitoring system according to claim 8, characterized in that, The monitored flange is the pitch system flange, yaw system flange, or main shaft connection flange of the wind turbine.

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