Abnormal detection method and system for the pitch limit mechanism of the impeller system

Abstract

This disclosure provides a method and system for detecting anomalies in the pitch limiting mechanism of an impeller system. The anomaly detection method includes: controlling the impeller system to perform a pitching action within a preset angle range including the pitch limiting position; during the pitching action, acquiring trigger angle data when the proximity switch is triggered, wherein the triggering of the proximity switch includes inductive triggering when the proximity switch senses the approach of the stop and disengagement triggering when the proximity switch senses the disengagement of the stop; and detecting whether an anomaly has occurred in the pitch limiting mechanism based on the difference between the trigger angle data and the preset angle data. This disclosure solves the problem of difficulty in accurately detecting anomalies in proximity switches and stops, and can more sensitively detect anomalies in the pitch limiting mechanism, thereby enabling timely maintenance and ensuring the safety of the unit.

Description

Technical Field

[0001] This disclosure relates to the field of wind power generation, and more specifically, to a method and system for detecting anomalies in the pitch limiting mechanism of a turbine system. Background Technology

[0002] As the capacity of wind turbine generators increases, the power generation loss caused by downtime per unit time is also increasing. Therefore, improving the availability of wind turbine generators, reducing downtime caused by false alarms, and achieving redundant operation of wind turbine generators have received increasing attention.

[0003] In wind turbine generators, the pitch system plays a crucial role in achieving maximum power point tracking and aerodynamic braking, and its reliability directly affects the safety of the wind turbine generator. For blade angle (or pitch angle) protection, an encoder can be used to measure the blade pitch angle. However, in some cases of generator malfunction or encoder failure, the encoder may rotate normally, but the actual blade angle of the wind turbine generator may not change. To address this, a proximity switch can be used to detect whether the actual blade position is correct, and the proximity switch is triggered by a stop block mounted on the moving ring of the bearing.

[0004] However, for proximity switches and stops, abnormal operation can generally only be detected when the proximity switch is damaged, power is cut off, or the actual installation of the stop is significantly deviated. This makes the detection of abnormalities in proximity switches and stops insufficiently sensitive, and it is impossible to alarm and take countermeasures in time when abnormalities occur, which poses certain safety hazards to the operation of the unit. Summary of the Invention

[0005] In view of the difficulty in accurately detecting anomalies of proximity switches and stops in related technologies, this disclosure provides an anomaly detection method and system for the pitch limiting mechanism of an impeller system.

[0006] The first aspect of this disclosure provides an anomaly detection method for a pitch limiting mechanism of an impeller system. The pitch limiting mechanism includes a proximity switch and a stop. The anomaly detection method includes: controlling the impeller system to perform a pitching action within a preset angle range including the pitch limiting position, wherein the proximity switch is disposed at the pitch limiting position; during the impeller system's pitching action, acquiring trigger angle data when the proximity switch is triggered, wherein the triggering of the proximity switch includes a sensing trigger when the proximity switch senses the approach of the stop and a disengagement trigger when the proximity switch senses the disengagement of the stop; and detecting whether an anomaly has occurred in the pitch limiting mechanism based on the difference between the trigger angle data and the preset angle data.

[0007] Optionally, the impeller system performs multiple reciprocating pitch maneuvers within the preset angle range. The preset angle data is the initial angle data when the proximity switch is first triggered during the multiple reciprocating pitch maneuvers. The step of detecting whether the pitch limiting mechanism is abnormal based on the difference between the trigger angle data and the preset angle data includes: determining a statistical value of the single-journey angle difference in the multiple reciprocating pitch maneuvers based on the single-journey angle difference between the trigger angle data and the preset angle data in each reciprocating pitch maneuver after the proximity switch is first triggered. The statistical value is the sum of the single-journey angle differences or the sum of the absolute values ​​of the single-journey angle differences. In response to the statistical value being greater than a preset threshold, it is determined that the pitch limiting mechanism is abnormal.

[0008] Optionally, the anomaly detection method is performed when the impeller system is without blades, wherein the step of controlling the impeller system to perform pitch control within a preset angle range including the pitch limit position includes: controlling the impeller system to perform pitch control within the preset angle range through a test platform.

[0009] Optionally, the step of controlling the impeller system to perform pitch control within a preset angle range including the pitch limit position includes: during the pitch control process, the test platform sends a speed switching command to the pitch controller of the impeller system, so that the pitch controller controls the impeller system to switch different pitch speeds to perform pitch control according to the speed switching command, wherein when the stop block is within a preset angle distance from the proximity switch, the test platform controls the impeller system to switch the pitch speed.

[0010] Optionally, the speed switching command includes a pitch speed to be switched, wherein the pitch speed to be switched is greater than the current pitch speed. During the execution of the pitch maneuver, the test platform sends a speed switching command to the pitch controller of the impeller system, causing the pitch controller to control the impeller system to switch to different pitch speeds according to the speed switching command. This step includes: during the execution of the pitch maneuver, in response to the pitch duration at the current pitch speed reaching a first duration, the test platform sends the speed switching command to the pitch controller, causing the pitch controller to control the impeller system to switch from the current pitch speed to the pitch speed to be switched, so that the stop generates acceleration before reaching the proximity switch.

[0011] Optionally, the preset threshold is greater than the difference threshold corresponding to a single pitching action, and less than the product of the number of round-trip pitching actions and the difference threshold.

[0012] Optionally, the anomaly detection method is performed during the operation of the wind turbine generator set, wherein the step of controlling the rotor system to perform pitch control within a preset angle range including the pitch limit position includes: controlling the rotor system to perform pitch control within the preset angle range at rated wind speed or under limited power operation state through the control system of the wind turbine generator set.

[0013] Optionally, the impeller system performs multiple reciprocating pitch maneuvers. The preset angle data is the initial angle data when the proximity switch is first triggered during the multiple reciprocating pitch maneuvers. The trigger angle data is obtained through the angle measuring device of the impeller system. The anomaly detection method further includes: in response to the proximity switch being triggered during a non-first reciprocating pitch maneuver, obtaining the sensing value of the angle measuring device of the impeller system; and performing fault detection on the angle measuring device based on the difference between the sensing value and the preset angle data.

[0014] A second aspect of this disclosure provides an anomaly detection system for a pitch limiting mechanism of an impeller system. The pitch limiting mechanism includes a proximity switch and a stop. The anomaly detection system includes a test platform and an angle measuring device. The test platform controls the impeller system to perform pitching actions within a preset angle range including the pitch limiting position. The proximity switch is located at the pitch limiting position. During the pitching action of the impeller system, the angle measuring device acquires trigger angle data when the proximity switch is triggered. The triggering of the proximity switch includes a sensing trigger when the proximity switch senses the approach of the stop and a disengagement trigger when the proximity switch senses the disengagement of the stop. The test platform detects whether an anomaly has occurred in the pitch limiting mechanism based on the difference between the trigger angle data and the preset angle data.

[0015] A third aspect of this disclosure provides a computer-readable storage medium that, when instructions in the computer-readable storage medium are executed by at least one processor, causes the at least one processor to perform an anomaly detection method for a pitch limiting mechanism of an impeller system according to this disclosure.

[0016] According to the abnormal detection scheme of the pitch limiting mechanism of the impeller system disclosed herein, the impeller system can be controlled to perform pitch control within a preset angle range including the pitch limiting position. During the pitch control process, the trigger angle data when the proximity switch is triggered can be acquired. Based on the difference between the trigger angle data and the preset angle data, it is possible to detect whether the pitch limiting mechanism has malfunctioned. In this way, the operation of the proximity switch and the stop during the pitch control process can be correlated with the pitch angle data. By comparing the blade angle when the proximity switch is triggered with the preset angle, even in the event of some inconspicuous abnormalities such as loose installation, the abnormality of the pitch limiting mechanism can be detected more sensitively, thereby enabling timely maintenance and ensuring the safety of the unit. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the structure of an impeller system according to an exemplary embodiment of the present disclosure.

[0018] Figure 2 This is a schematic diagram illustrating the installation of a proximity switch in an impeller system according to an exemplary embodiment of the present disclosure.

[0019] Figure 3 This is a flowchart illustrating an anomaly detection method for a pitch limiting mechanism of an impeller system according to an exemplary embodiment of the present disclosure.

[0020] Figure 4 This is a flowchart illustrating the steps of detecting whether the pitch limiting mechanism is abnormal in an abnormality detection method for a pitch limiting mechanism of an impeller system according to an exemplary embodiment of the present disclosure.

[0021] Figure 5 This is a schematic diagram illustrating the topology of an anomaly detection method for a pitch limiting mechanism of an impeller system according to an exemplary embodiment of the present disclosure.

[0022] Figure 6 This is a schematic diagram showing the torque variation curve of the pitch motor during the start-up and shutdown process of the impeller system under no-load operation according to an exemplary embodiment of the present disclosure.

[0023] Figure 7 This is a schematic diagram illustrating the control timing of the pitch speed in an abnormality detection method for a pitch limiting mechanism of an impeller system according to an exemplary embodiment of the present disclosure.

[0024] Figure 8 This is a schematic diagram illustrating the relationship between pitch speed and pitch angle in an anomaly detection method for a pitch limiting mechanism of an impeller system according to an exemplary embodiment of the present disclosure.

[0025] Figure 9This is a flowchart illustrating an example of the application of an anomaly detection method for the pitch limiting mechanism of an impeller system according to an exemplary embodiment of the present disclosure in the factory inspection of the unit.

[0026] Figure 10 This is a flowchart illustrating an example of the application of an anomaly detection method for a pitch limiting mechanism of a turbine system according to an exemplary embodiment of the present disclosure in wind farm operation.

[0027] Figure 11 This is a schematic block diagram illustrating an anomaly detection system for a pitch limiting mechanism of an impeller system according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0028] The following detailed embodiments are provided to aid the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein, but may be changed as will become clear upon understanding this disclosure, except for operations that must occur in a specific order. Furthermore, for clarity and conciseness, descriptions of features known in the art may be omitted.

[0029] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein, which will become clear upon understanding the disclosure of this application.

[0030] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more.

[0031] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts should not be limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Thus, without departing from the teaching of the examples described herein, the first component, first assembly, first region, first layer, or first part referred to as the first component, first assembly, first region, first layer, or first part may also be referred to as the second component, second assembly, second region, second layer, or second part.

[0032] In the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to," or "bonded to" another element, the element may be directly "on" another element, directly "connected to," or "bonded to" the other element, or one or more other elements may be present in between. Conversely, when an element is described as being "directly on" another element, "directly connected to," or "directly bonded to" another element, no other elements may be present in between.

[0033] The terminology used herein is for the purpose of describing various examples only and is not intended to limit disclosure. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. The terms “comprising,” “including,” and “having” indicate the presence of the described features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0034] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains upon understanding this disclosure. Unless expressly defined herein, terms (such as those defined in a general dictionary) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field and in this disclosure, and shall not be interpreted in an idealized or overly formalistic manner.

[0035] Furthermore, in the description of the examples, detailed descriptions of well-known related structures or functions will be omitted when it is believed that such detailed descriptions would lead to a vague interpretation of this disclosure.

[0036] As mentioned earlier, there is a problem with accurately detecting anomalies in proximity switches and stops in related technologies.

[0037] Specifically, in the pitch system of a wind turbine generator, two encoders are typically used to detect the angle simultaneously. One encoder is located at the tail of the pitch motor and acts as the main rotary encoder to calculate the blade angle, while the other encoder is located on the internal teeth of the pitch bearing and acts as the auxiliary rotary encoder to detect the blade angle. When the angle difference detected by the two encoders is too large, the pitch system triggers a fault and retracts the pitch to shut down the turbine, thus protecting the safety of the unit.

[0038] Generally, absolute encoders can be used to measure the pitch angle of a pitch system with pitch bearings. However, when using encoders, a Synchronous Serial Interface (SSI) signal measurement module is required, which is costly. Furthermore, since the transmission ratio parameter of the encoder on the internal teeth of the pitch bearing does not include the reduction ratio of the gearbox, the calculated angle value is not very accurate compared to the angle value calculated by the main rotary encoder, resulting in a high cost and low efficiency.

[0039] However, since the main encoder is installed at the tail of the motor, that is, on the drive unit, when there is a problem with the transmission mechanism, such as a mechanical failure in the reducer, an abnormality in the toothed belt, wear of the pitch bearing clearance, or a failure of the main encoder, the main encoder may rotate normally, but the actual blade angle of the wind turbine may not change, that is, the driven device may not actually move. This situation cannot be detected by using only the main encoder.

[0040] In related technologies, the actual position of the blade can be detected by a proximity switch, and the proximity switch can be triggered by a stop installed on the moving ring of the bearing.

[0041] For example, during factory inspection, proximity switch fault detection conditions may include: the proximity switch still triggers when the angle is greater than 6.5 degrees; and / or, the proximity switch does not trigger when the angle is less than 3 degrees, i.e., the angle range is 3 to 6.5 degrees. In this detection method, anomalies are generally only detected when the proximity switch is damaged, power is cut off, or the actual installation of the stop is significantly off-center. It cannot detect subtle anomalies such as loosening of the stop or proximity switch. However, if there is a loose installation, during continuous operation after delivery to the site, it may loosen further or even detach. Besides causing the wind turbine generator to shut down, this could also lead to the stop failing and rotating beyond the limit switch position, posing a safety hazard to the unit's operation.

[0042] In one example, the looseness of a proximity switch or stop can be detected manually by shaking it to check for any obvious looseness. However, this method only detects the situation at that moment and cannot be used to detect looseness during the operation of the pitch system, especially after the wind turbine has been running for a long time. Furthermore, the sensitivity of human touch varies from person to person, making it difficult to detect even slight looseness. In addition, real-time monitoring of wind turbines in operation at a wind farm is also impossible.

[0043] In another example, the loosening of a proximity switch or stop can be detected by detecting whether a fault is triggered. However, this method can only detect more serious situations and cannot detect early loosening of the proximity switch, especially for wind turbines operating at wind power sites, thus failing to provide early warning.

[0044] In another example, a proximity switch or stop can be detected for looseness by detecting an angle change threshold. This method checks if the angle difference between two proximity switch triggers is greater than a set threshold; if it is, looseness is determined. The drawback of this method is that it is limited by the threshold and the operating conditions of the wind turbine. Specifically, if the threshold is set too high, and considering the combined effects of motor drive force, wind force, and wind direction on the pitch system bearings during operation, it may lead to inaccurate detection of anomalies. Conversely, if the threshold is set too low, slight vibrations of the blades and bearings may cause false detections.

[0045] In view of the above problems, this disclosure provides an anomaly detection method, an anomaly detection device, and a computer-readable storage medium for the pitch limiting mechanism of a wind turbine rotor system, in order to solve or at least alleviate the above problems.

[0046] According to a first aspect of an exemplary embodiment of the present disclosure, a method for detecting anomalies in the pitch limiting mechanism of a wind turbine rotor system is provided. This method can be performed during the factory inspection of the wind turbine, for example, by a test bench used for factory inspection; or it can be performed during the operation of the wind turbine, for example, by the main control system of the wind turbine or the control system of the wind farm.

[0047] In an example application scenario, during factory inspection, the test platform can control the impeller system to perform pitch control within a preset angle range, including the pitch limit position. A proximity switch is positioned at the pitch limit position. During the pitch control process, the platform acquires the trigger angle data when the proximity switch is activated. The triggering of the proximity switch includes both induction triggering when the proximity switch senses the approach of the stop and disengagement triggering when the proximity switch senses the stop disengagement. Based on the difference between the trigger angle data and the preset angle data, the platform detects whether any abnormalities have occurred in the proximity switch or the stop.

[0048] The abnormal detection method of the pitch limiting mechanism of the impeller system according to the embodiments of the present disclosure can correlate the operation of the proximity switch and the stop during the pitch change with the pitch angle data. By comparing the blade angle when the proximity switch is triggered with the preset angle, even in the event of some inconspicuous abnormalities such as loose installation, the abnormality of the pitch limiting mechanism can be detected more sensitively, thereby enabling timely maintenance and ensuring the safety of the unit.

[0049] Before describing the anomaly detection method of the pitch limiting mechanism of the embodiments of this disclosure, the structure of the rotor system of the wind turbine generator set and the start-up and shutdown process of the rotor system under no-load operation are first described as an example.

[0050] like Figure 1 As shown, the impeller system includes a hub 101, a pitch bearing 102, a pitch control cabinet 103, a pitch motor 104, a drive gear 105, a proximity switch bracket 106, and a stop block 107.

[0051] The hub 101 is the mechanical support structure of the impeller system. The pitch bearing 102 is mounted on the hub 101, connecting the blades and driving their rotation (pitch adjustment). The pitch control cabinet 103 is installed inside the hub 101, controlling the pitch system and driving the pitch motor 104. The pitch motor 104 is connected to the drive gear 105 via a reducer (not shown). The drive gear 105 meshes with the inner ring gear of the pitch bearing 102, thereby driving the pitch bearing 102 to rotate. The proximity switch bracket 106 is mounted and fixed on the hub 101, used to detect the actual position information of the pitch bearing. The stop block 107 is mounted on the pitch bearing 102 and rotates synchronously with it. (Reference) Figure 1 The cross section shown indicates that, during operation, the pitch bearing rotates clockwise or counterclockwise in a direction parallel to the plane of the paper.

[0052] A proximity switch is a position switch that can be operated without direct mechanical contact with moving parts. When an object approaches the sensing surface of the switch to the operating distance, the switch can be activated without mechanical contact or the application of any pressure. It has the characteristics of a limit switch and a micro switch. In a pitch limit mechanism, when the stop enters the sensing range of the proximity switch, it can sense and trigger the proximity switch, causing a change in the level of the proximity switch; when the stop leaves the sensing range of the proximity switch, it can disengage from triggering the proximity switch, which will also cause a change in the level of the proximity switch.

[0053] In the above system, a 3° (or 5°) proximity switch is installed on the proximity switch bracket 106. The physical meaning of the 3° (or 5°) proximity switch is that when the stop 107 is rotated to this position, the angle measured by the encoder inside the pitch motor 104 is 3° (or 5°), which indicates that the actual position of the blade is 3° (or 5°). Since the encoder is located inside the pitch motor, and the pitch motor 104 is the driving mechanism, the encoder's measurement value cannot strictly represent the position of the driven mechanism. It is necessary to detect the actual position of the blade through a proximity switch (or other sensor) to ensure the normal operation of the wind turbine.

[0054] The following will combine Figure 2 The fault detection principle according to embodiments of this disclosure is described.

[0055] Specifically, when stop 107 moves to the position of the proximity switch, the proximity switch is triggered and outputs a high level; when stop 107 disengages from the proximity switch, the high level of the proximity switch changes to a low level. Each level change of the proximity switch can be considered a trigger. However, during factory installation or inspection, and during the operation of the wind turbine generator set, the proximity switch and stop 107 may become loose. In the existing fault detection logic, it detects whether the proximity switch triggers abnormally within a certain angle range (e.g., no trigger, or triggering even after the stop disengages), but it cannot detect the loosening of the proximity switch. As the operating time increases, the loosening gradually worsens, eventually leading to the risk of proximity switch failure or stop disengagement, causing serious damage to mechanical components, such as rotation or collision after the stop disengages, and causing other problems due to the inability to trigger the limit switch.

[0056] like Figure 2 As shown, the stop block can be installed through the elongated mounting hole 201, and its installation position 202 can be close to the edge. Therefore, it is prone to loosening due to vibration after the hub has been running for a long time (especially after the load of the blades). During the final assembly of the unit, there may be situations such as insufficient tightening, personnel forgetting to tighten during installation, and the trigger distance between the proximity switch and the stop block being unqualified (i.e., the vertical distance between the proximity switch and the stop block is too far). These situations can also lead to the failure to identify the fault, which will have a certain impact on subsequent process testing, factory quality, and even the on-site operation of the unit.

[0057] Based on the above reasons, embodiments of this disclosure provide an abnormality detection method for the pitch limiting mechanism of an impeller system. This method and its additional details enable more accurate and sensitive detection of abnormalities in the pitch limiting mechanism of the impeller system, such as detecting loosening of proximity switches and stops.

[0058] The following will refer to Figure 3This invention describes an anomaly detection method for a pitch limiting mechanism of an impeller system according to embodiments of the present disclosure, wherein the pitch limiting mechanism includes a proximity switch and a stop, and the method may include the following steps:

[0059] like Figure 3 As shown, in step S310, the impeller system can be controlled to perform pitching action within a preset angle range including the pitch limit position.

[0060] Here, the proximity switch can be set at the pitch limit position, and the proximity switch can be triggered when the stop approaches or disengages from the proximity switch. The pitch limit position can be, for example, a preset blade angle position, and the preset angle range can be, for example, a 90-degree angle range including the pitch limit position, such as 0 degrees to 90 degrees, so that the stop can sense contact or disengagement with the proximity switch during pitch adjustment. The pitch limit position can be located at, for example, at the end angle position of the preset angle range, or it can be located near the end angle position of the preset angle range.

[0061] Furthermore, it should be noted that the pitch control action mentioned in this article can be performed with blades installed in the impeller system or without blades installed in the impeller system. The angle data refers to the pitch angle data, which can be obtained regardless of whether blades are installed.

[0062] In step S320, the trigger angle data when the proximity switch is triggered can be obtained during the process of the impeller system performing pitch control.

[0063] Here, the triggering of the proximity switch can include induction triggering when the proximity switch senses the approach of the stop and disengagement triggering when the proximity switch senses the disengagement of the stop.

[0064] As an example, when performing a pitching action, the stop can move closer to or away from the proximity switch as the bearing moves. For instance, when the stop approaches the proximity switch, the proximity switch is triggered and outputs a high level; when the stop moves away from the proximity switch, the proximity switch is triggered and outputs a low level.

[0065] In step S330, the pitch limit mechanism can be checked for abnormality based on the difference between the trigger angle data and the preset angle data.

[0066] In one example, the impeller system can perform a single-stroke pitch control action within a preset angle range. A single-stroke pitch control action can refer to the stop passing through the preset angle range once and approaching or disengaging from the proximity switch once. Here, an abnormality in the pitch limit mechanism can include, for example, the proximity switch or the stop becoming loose.

[0067] In this example, the angle data is the blade pitch angle (also known as the pitch angle). In wind turbine generators, variable pitch control can be used to adjust the power output by adjusting the blade's angle of attack. The pitch angle refers to the angle between the blade and the rotor plane.

[0068] The preset angle data may include a single-stroke difference threshold. If the triggered angle data exceeds this threshold, it can be used to determine that an abnormality has occurred in the pitch limit mechanism, such as a loose proximity switch or stop. The single-stroke difference threshold can be set according to actual needs, for example, it can be determined empirically.

[0069] In another example, the impeller system can perform multiple reciprocating pitch movements within a preset angle range. The preset angle data can be the initial angle data when the proximity switch is first triggered during the multiple reciprocating pitch movements.

[0070] Here, the reciprocating pitch action can refer to the pitch system shifting from one boundary angle to the other within a preset angle range, and then shifting back from the other angle to the first boundary angle. For example, it can first shift the pitch clockwise (or counterclockwise) from the first boundary angle to the second boundary angle, and then shift the pitch counterclockwise (or clockwise) from the second boundary angle to the first boundary angle.

[0071] In this example, such as Figure 4 As shown, the following methods can be used to detect whether the pitch limit mechanism is malfunctioning:

[0072] In step S410, the statistical value of the single-trip angle difference in multiple reciprocating pitch actions can be determined based on the single-trip angle difference between the trigger angle data and the preset angle data in each reciprocating pitch action after the proximity switch is first triggered. The statistical value is the sum of the single-trip angle differences or the sum of the absolute values ​​of the single-trip angle differences.

[0073] Specifically, the angle data at the first trigger can be used as the preset angle data. In cases of non-first triggers, such as starting from the second trigger of the proximity switch, the one-way angle difference between the trigger angle data and the preset angle data at each non-first trigger can be recorded, and these one-way angle differences can be accumulated to obtain the total angle difference.

[0074] In this step, the accumulation of the single-trip angle differences can be achieved by directly adding these single-trip angle differences together, or by adding the absolute values ​​of each single-trip angle difference together.

[0075] Specifically, with Figure 1 and Figure 2Taking the structure shown as an example, since the stop block rotates with the pitch bearing, and the stop block is generally installed near the pitch position, such as a rectangular mounting hole (e.g., on one side / end of the rectangular mounting hole), when the bearing rotates from top to bottom, the stop block may move due to loosening, causing a change in the trigger angle, for example, a smaller trigger angle; while when rotating in the other direction, the stop block will be moved again by the mounting hole (e.g., Figure 2 The installation position 202 shown is blocked by the edge of the hole, that is, the trigger angle becomes the normal position or the initial position, so the probability of its accumulation and positive and negative cancellation is low. Therefore, in this example, positive and negative difference values ​​will not appear frequently. Even without the method of absolute value accumulation, the anomaly can be effectively identified, ensuring the accuracy of the detection algorithm.

[0076] As an example, in the unloaded state of the impeller system without blades, the statistical value can be the sum of the differences in angles over one stroke, or the sum of their absolute values. Furthermore, in the state where the impeller system has blades installed, the statistical value can be the sum of the absolute values ​​of the differences in angles over one stroke. Here, when the impeller system has blades installed, the blades often oscillate alternately in two directions. For the stop on the installed pitch bearing, the result may be that the angle is once less than the initial angle and once greater than the initial angle. In this case, using the sum of absolute values ​​is more conducive to identifying anomalies and avoids the probability of the sum being canceled out or reduced due to the addition of positive and negative values.

[0077] Here, the initial angle recorded during the first trigger in the detection process is used as a reference value for subsequent detections. This eliminates the need to preset other specific parameters or thresholds, thus enabling adaptive detection.

[0078] In step S420, if the statistical value is greater than a preset threshold, it can be determined that the proximity switch and the stop are abnormal.

[0079] Here, a preset threshold can be set for the statistical value of the single-trip angle difference that is not triggered for the first time. If the statistical value is greater than the preset threshold, it can be considered that the pitch limit mechanism is abnormal; if the statistical value is not greater than the preset threshold, it can be considered that the pitch limit mechanism is not abnormal.

[0080] By employing the above method, subtle angular differences caused by minor anomalies can be accumulated during multiple pitch-up maneuvers, allowing for more sensitive detection of malfunctions in the proximity switches or stops of the pitch-up limiting mechanism. Furthermore, the preset threshold for statistical values ​​can be set relatively low, enabling more accurate early loosening detection. Compared to methods that directly detect single-change thresholds, setting a threshold for statistical values ​​representing the accumulation of multiple differences effectively avoids missed or false detections.

[0081] As an example, the preset threshold can be set according to actual needs or experience. For example, the preset threshold can be greater than the difference threshold corresponding to a single round-trip pitching action (such as the single-trip difference threshold mentioned above) and less than the product of the number of round-trip pitching actions and the difference threshold.

[0082] Specifically, in actual pitch control, if the proximity switch or stop exhibits subtle abnormalities during multiple triggering events, these abnormalities may only be observed in a portion of the triggering processes, while not in other triggering processes. Therefore, the preset threshold can be larger than the threshold for single-trigger determination. However, embodiments of this disclosure also consider that the difference threshold for multiple triggering events is not simply the sum of the single-trip difference thresholds, but rather that there may be triggering processes that do not exhibit abnormalities. Therefore, the preset difference threshold for multiple triggering events can be smaller than the sum of the single-trip difference thresholds. By setting the preset threshold in this way, abnormalities in the proximity switch or stop can be detected more accurately.

[0083] In the embodiments of this disclosure, the anomaly detection method can be applied to factory inspection and / or wind farm operation sites to detect loose proximity switches or stops and issue early warning information in advance, ensuring the quality or stable operation of the unit. Here, early warning refers to the timely detection of abnormal information based on past patterns or observed potential precursors before a fault occurs, in order to prevent faults or hazards from occurring unknowingly or without adequate preparation, thereby minimizing the failure rate and the resulting losses.

[0084] The following sections will describe application examples of this method in both factory inspection and wind farm operation scenarios.

[0085] As an example, in a factory inspection scenario, anomaly detection methods can be performed when the impeller system is in a state without blades installed (also known as "no-load state").

[0086] In this example, in step S310 above, the impeller system can be controlled by the test platform to perform pitching action within a preset angle range.

[0087] The following reference Figure 5 An example is described of a topology for implementing an anomaly detection method according to an exemplary embodiment of the present disclosure in a factory inspection scenario.

[0088] like Figure 5As shown, in this topology, the test platform interacts with the pitch controller via Decentralized Periphery (DP) communication and also exchanges safety chain signals with the pitch controller. The pitch controller controls the driver's operation via Controller Area Network (CAN) communication. The pitch driver drives the pitch motor and controls the pitch motor's brake cable. An encoder is installed inside the pitch motor; the absolute value signal from the encoder is fed back to the pitch controller, and the incremental signal from the encoder is fed back to the pitch driver. In addition, the pitch driver can acquire signals from the proximity switch. The pitch controller can send the angle signal (absolute value signal) acquired by the encoder and the proximity switch signal to the test platform via DP communication.

[0089] When the pitch system is fault-free, the test platform controls its operation through preset reciprocating running ranges and speed variations. Upon receiving control commands from the test platform, the pitch system operates via the pitch driver, enabling continuous reciprocating operation at a preset speed. During this process, the test platform acquires the high and low voltage levels of the proximity switch and performs algorithmic analysis on the angle values ​​measured by the encoder, thereby detecting any loose proximity switches.

[0090] In this application scenario, during the factory testing of the impeller system, the test platform will control the operation of the pitch system. For example, this could involve controlling the three pitch bearings on each side to continuously and alternately rotate clockwise and counterclockwise within an angle range of 0 to 90 degrees for an extended period. During no-load operation testing, the three pitch bearings typically rotate simultaneously. No-load testing is a stage in the factory testing of the impeller system, which refers to the continuous, alternating clockwise and counterclockwise rotation of the pitch bearings within an angle range such as 0 to 90 degrees.

[0091] Because the operation is a back-and-forth motion with acceleration and deceleration during no-load operation, the proximity switch is triggered more frequently, which improves the reliability of the detection results. For example, if the no-load operation lasts for 10 minutes with an average speed of 2 degrees / second, then the number of back-and-forth motions (the number of times the stop rotates to or disengages from the proximity switch) is: 10 minutes * 60 seconds * 2 times / [(90 degrees - 0 degrees) / 2 degrees / second] = 26 times. The multiplication by 2 is because the moment the stop just triggers the proximity switch (from low level to high level) and the moment the stop just disengages from the proximity switch (from high level to low level) can both be counted as one instance.

[0092] Furthermore, during the no-load operation test, the starting and stopping of the pitch motor will generate a certain force, i.e., force F = Ma, where M represents mass and a represents acceleration. Since the hub is a single-piece structure, the force F of acceleration will act on the hub, causing vibration of the proximity switch bracket 106. If the proximity switch is loose, its position will change by a certain amount, causing the angle measured by the encoder to shift when the stop is triggered again.

[0093] Specifically, during no-load operation, the torque changes of the pitch motor during start-up and shutdown are shown in [the relevant documentation]. Figure 6 As shown, the green curve represents the blade angle value (i.e., the rotation during one no-load operation), and the purple curve represents the pitch motor torque. Figure 6 It can be seen that the pitch motor torque exhibits significant spikes when starting and stopping. The conversion relationship between torque and force is as follows:

[0094] F = T / r(1)

[0095] Where T is torque, F is force, and r is radius. Figure 3 Taking the data as an example, the torque peak moment reaches 300 Nm, while the radius of the rotating shaft of the pitch motor is generally 4 cm, or 0.04 m. Therefore, the force on the motor side can be calculated as 300 / 0.04 = 7500 N.

[0096] Furthermore, since the transmission relationship of torque is as follows:

[0097]

[0098] N1 represents the torque on the driving side, and N2 represents the torque on the driven side. n1 is the number of teeth on the driving side, and n2 is the number of teeth on the driven side. That is, for the transmission mechanism, the torque is directly proportional to the mechanical gears. Therefore, the torque acting on the pitch bearing will be greater, resulting in a larger diameter pitch bearing. For example, the radius of the pitch bearing may be 2 meters, but from... Figure 1 As can be seen in the example, the number of teeth of the pitch bearing 102 is much greater than the number of teeth of the drive gear 105, which will eventually lead to vibration of the pitch bearing and the hub. This vibration will also be transmitted to the proximity switch bracket 106, causing the proximity switch to vibrate.

[0099] Therefore, in the above example, the characteristics of the impeller system's reciprocating motion during the no-load operation process during factory testing are utilized. Acceleration is generated by changing the pitch direction, which causes a certain vibration. The existing no-load operation process during factory testing can be used to detect the looseness of the proximity switch and the stop on the basis of the existing test procedure.

[0100] In addition to generating acceleration by changing the pitch direction during round trip operation, according to embodiments of this disclosure, different operating speeds can also be switched through a test platform to generate a certain acceleration.

[0101] Specifically, in step S310 above, during the execution of the pitch change action, the test platform can send a speed switching command to the pitch controller of the impeller system, so that the pitch controller controls the impeller system to switch different pitch speeds to execute the pitch change action according to the speed switching command. Among them, when the distance between the stop block and the proximity switch is within a preset angle distance, the test platform controls the impeller system to switch the pitch speed.

[0102] Here, the preset angle distance can be the leaf angle range of the block that is about to sense and trigger the proximity switch, for example, it can be within the angle range of 3° or 5° from the proximity switch.

[0103] By switching the pitch speed when the proximity switch is nearby, the stop can have a certain acceleration when it reaches the proximity switch, thereby amplifying the vibration of both, making the detection conditions more stringent, and thus improving the accuracy of the detection results.

[0104] As an example, the speed switching command may include the pitch speed to be switched, which may be greater than the current pitch speed. In this example, during the execution of the pitch action, the test platform sends a speed switching command to the pitch controller of the impeller system, so that the pitch controller controls the impeller system to switch to different pitch speeds according to the speed switching command. The steps of executing the pitch action may include: during the execution of the pitch action, in response to the pitch duration at the current pitch speed reaching a first duration, the test platform sends a speed switching command to the pitch controller, so that the pitch controller controls the impeller system to switch from the current pitch speed to the pitch speed to be switched, so that the stop generates acceleration before reaching the proximity switch.

[0105] Specifically, in this method, a predetermined duration (e.g., the first duration mentioned above) can be run at each pitch speed. When the duration is reached, the detection at the corresponding pitch speed can be considered to be over, and the detection can be switched to the next pitch speed. The switch can be from the current pitch speed to a larger pitch speed, so that the stop can generate acceleration before reaching the proximity switch, making the detection results more reliable.

[0106] Figure 7 A control timing diagram for controlling the running speed in an anomaly detection method according to an embodiment of the present disclosure is shown. Figure 7 In this system, a positive velocity value indicates a 90-degree pitch, while a negative velocity value indicates a 0-degree pitch. Switching between numerical values ​​indicates a change in the absolute value of the velocity.

[0107] like Figure 7 As shown, during no-load operation, changes in pitch direction and speed will cause certain vibrations due to the generation of acceleration. This embodiment of the method utilizes this process to detect the loosening of proximity switches or stops.

[0108] Furthermore, such as Figure 8 As shown, the testing platform can detect angle data in real time. When the angle data is close to 3° or 5°, the testing platform switches to the no-load running speed at this moment. In this way, vibration values ​​can be generated near the proximity switch, which increases the number of vibrations and the immediacy of the vibration, thereby achieving more accurate and timely loosening detection and diagnosis.

[0109] Figure 9 This paper presents an application example of detecting anomalies in the pitch limit mechanism during factory testing using an unloaded running process.

[0110] like Figure 9 As shown, in step S901, the impeller system can be started under no-load operation. In step S902, it is determined whether the proximity switch is triggered (e.g., stop sensing trigger or stop disengagement trigger). If the proximity switch is not triggered, step S902 can continue to be executed to monitor the triggering of the proximity switch.

[0111] In response to the proximity switch being triggered, in step S903, the initial angle data of the current blade can be recorded, and the count value is incremented by 1. In step S904, it can be determined whether the proximity switch has been triggered again. If the proximity switch has not been triggered again, step S904 can continue to be executed to monitor the triggering of the proximity switch.

[0112] In response to the proximity switch being triggered again, in step S905, the angle data at the time of triggering can be recorded, and the difference between this angle and the initial angle data can be calculated to obtain the single-trip angle difference. The currently obtained single-trip angle differences are then summed to obtain a statistical value of the difference for each trigger, such as the sum of the differences or the absolute values ​​of the differences. In step S906, it can be determined whether the first duration of the current no-load running speed has been reached. If the first duration has not been reached, the process can return to step S904 to continue determining whether the proximity switch has been triggered again.

[0113] In response to reaching the first duration, in step S907, the idle operating speed can be switched, and steps S902 to S906 above can be executed again at the switched idle operating speed.

[0114] In step S907, multiple speed switching may be included. Specifically, during no-load operation, the pitch speed can be continuously switched, such as 1 degree / second, 2 degrees / second, 3 degrees / second, etc., so as to generate a certain vibration value by using the speed switching to detect whether the proximity switch and the stop have become loose.

[0115] After each speed switch and completion of steps S902 to S906 at that speed, in step S908, it can be determined whether the second duration of no-load operation has been reached. The second duration can be arbitrarily set according to actual needs, such as 5 minutes or 10 minutes. In response to the failure to reach the second duration, the process can return to step S907, switch the pitch speed, and perform detection at the switched speed.

[0116] In response to the arrival of the second duration, in step S909, it can be determined whether the current statistical value is greater than a preset threshold. If the statistical value is not greater than the preset threshold, it can be considered that no loosening abnormality has occurred, and the detection ends; if the statistical value is greater than the preset threshold, it can be considered that a loosening abnormality has occurred, and in step S9010, a loosening alarm message can be output.

[0117] In the above-mentioned anomaly detection method, variable-speed no-load operation can be used when the impeller system is running under no-load conditions. That is, during the reciprocating test, the pitch motor is controlled to run at different speeds. This verifies the pitch adjustment function and stability of the pitch system, and increases mechanical vibration by switching speeds, indirectly aiding in the detection of loose proximity switches or stops. Specifically, according to the mechanical expression F=ma mentioned above, the acceleration a can be expressed as a=(vt-v0) / t, where vt represents the speed after switching, v0 represents the current speed, and t represents the switching time. When the pitch speed changes suddenly, such acceleration is generated. This acceleration acts as a force on the pitch bearing and hub, thus affecting the force on the stop, resulting in better detection conditions and improving the reliability of the detection results.

[0118] Furthermore, in the above-mentioned anomaly detection method, during no-load operation, the total detection duration (e.g., the second duration mentioned above) can be divided into several time periods (e.g., the first duration corresponding to each speed mentioned above). After each time period is reached, the pitch speed is directly switched, which may include speed-up control or speed-down no-load control. Here, the operating speed can also be controlled at the maximum speed allowed by the pitch motor. The working condition that generates hub vibration is simulated by the speed switching and the acceleration generated by starting and stopping during round trip operation.

[0119] As another example, anomaly detection methods can also be implemented during the operation of wind turbine generators.

[0120] Specifically, in step S310 above, the step of controlling the rotor system to perform pitch control within a preset angle range including the pitch limit position may include: controlling the rotor system to perform pitch control within a preset angle range under rated wind speed or under limited power operation conditions through the control system of the wind turbine generator set.

[0121] When the wind turbine is running on site, the pitch system will continuously adjust the pitch during operation, including starting, stopping, accelerating and decelerating the pitch motor. Therefore, by utilizing the reciprocating pitch adjustment operation characteristics of the pitch system, the above-mentioned detection conditions during no-load operation can also be achieved to realize accurate detection.

[0122] Furthermore, as an example, when the impeller system performs multiple reciprocating pitch maneuvers, the preset angle data can be the initial angle data when the proximity switch is first triggered during the multiple reciprocating pitch maneuvers. The trigger angle data can be obtained through the impeller system's angle measuring device. Here, the angle measuring device can be, for example, an encoder.

[0123] In this example, the anomaly detection method may further include: in response to the proximity switch being triggered during a non-first reciprocating pitching action, acquiring the sensing value of the angle measuring device of the impeller system; and performing fault detection on the angle measuring device based on the difference between the sensing value and preset angle data.

[0124] Specifically, when the wind turbine is running on-site, considering the interference and influencing factors at the scene, the angle measuring device may experience data jumps. Therefore, in this application scenario, it is possible to verify whether the sensing value of the angle measuring device is normal, perform jump detection, eliminate interference caused by the jump of the angle measuring device, and improve the accuracy of the detection.

[0125] Here, the first sensing value collected by the angle measuring device when the proximity switch is triggered for the first time can be compared with the second sensing value collected when the proximity switch is not triggered for the first time. When the difference between the two is large, it can be considered that the angle measuring device has malfunctioned.

[0126] For example, in response to the difference between the first sensing value and the second sensing value being greater than a preset sensing value difference threshold, it can be determined that the angle measuring device has malfunctioned. The sensing value difference threshold can be greater than the aforementioned single-trip difference threshold. Thus, when the single-trip angle difference exceeds the single-trip difference threshold but is less than the sensing value difference threshold, it can be considered that an abnormality has occurred in the pitch limit mechanism; and when the single-trip angle difference exceeds the sensing value difference threshold, it can be considered that the angle measuring device has malfunctioned.

[0127] Figure 10 This paper presents an application example of detecting abnormalities in the pitch limiting mechanism by utilizing the pitch adjustment characteristics of the wind turbine during operation in a field scenario.

[0128] like Figure 10 As shown, in step S1001, it can be determined whether the rated wind speed or power limit operation has been reached. If the rated wind speed or power limit operation has not been reached, the detection can be terminated.

[0129] In response to reaching the rated wind speed or operating at limited power, in step S1002, it can be determined whether the proximity switch is triggered (e.g., stop sensing trigger or stop disengagement trigger). If the proximity switch is not triggered, step S1002 can continue to be executed to monitor the triggering of the proximity switch.

[0130] In response to the proximity switch being triggered, in step S1003, the initial angle data of the current blade can be recorded, and the count value is incremented by 1. Similarly, the initial angle data at the first trigger can be recorded as a reference angle, without the need to preset specific parameters or thresholds, thus enabling adaptive detection.

[0131] In step S1004, it can be determined whether the proximity switch has been triggered again. If the proximity switch has not been triggered again, step S1004 can continue to be executed to monitor the triggering of the proximity switch.

[0132] In response to the proximity switch being triggered again, in step S1005, it can be determined whether the angle has changed abruptly. For example, it can be determined whether the difference between the currently detected angle data and the initial angle data is greater than a preset sensing value difference threshold. If it is greater than the sensing value difference threshold, the angle is considered to have changed abruptly; if it is less than or equal to the sensing value difference threshold, the angle is considered not to have changed abruptly. In response to the angle changing abruptly, it can be considered that the angle measuring device has malfunctioned, and the detection ends.

[0133] In response to no angle jump, in step S1006, the angle data at the time of triggering can be recorded, and the difference between this and the initial angle data can be calculated to obtain the single-trip angle difference. The currently obtained single-trip angle differences are then summed to obtain the difference statistics for each trigger, such as the cumulative sum of differences or the cumulative sum of absolute differences. In step S1007, it can be determined whether the current detection duration has reached the preset third duration. If the third duration has not been reached, the process can return to step S1004 to continue monitoring whether the proximity switch is triggered again. Upon triggering, the single-trip angle difference and the current difference statistics are obtained. Here, the third duration can be greater than the second duration, for example, it can be 1 hour. During unit operation, detection can be performed every 1 hour.

[0134] In response to reaching the third time interval, in step S1008, it can be determined whether the current statistical value is greater than a preset threshold. If the statistical value is not greater than the preset threshold, it can be considered that no loosening abnormality has occurred, and the detection ends; if the statistical value is greater than the preset threshold, it can be considered that a loosening abnormality has occurred, and in step S1009, a loosening alarm message can be output.

[0135] Table 1 below shows examples of angle data, angle differences, and sums of differences obtained using the anomaly detection method according to embodiments of the present disclosure.

[0136] Table 1

[0137]

[0138]

[0139] As shown in Table 1 above, the initial angle data at the initial trigger is 6.52 degrees. Each time the proximity switch triggers or disengages, the difference between this initial angle data and the actual angle data of 6.52 degrees is calculated. All the differences are then summed. If the sum of the differences is greater than a preset threshold, such as 0.1 degrees, it is determined that the proximity switch and the stop have become loose. According to this method, the preset threshold can be set relatively small, thus achieving more accurate early loosening detection. Compared with methods that directly detect threshold changes in a single instance, this effectively avoids missed detections and false detections.

[0140] The abnormal detection method for the pitch limiting mechanism of the impeller system according to the embodiments of this disclosure can utilize the reciprocating characteristics of the impeller system during no-load operation under factory testing to detect the loosening of proximity switches and stops. Furthermore, this method is not limited by fault triggering conditions or judgment thresholds, and can achieve accurate loosening detection and fault early warning under any operating condition. It is particularly suitable for wind turbine generators operating in wind farms with continuous pitch adjustment, and can naturally eliminate the influence of wind conditions.

[0141] Specifically, in one example, the mechanical vibration of the pitch bearing during start-up, shutdown, and rotation under no-load conditions is used to simulate hub vibration, thereby detecting the stop trigger angle. This achieves automatic detection, avoiding manual inspection, and simulates and tests vibration conditions under no-load conditions. Thus, stop loosening can be detected promptly during pitch system operation, ensuring the unit's factory quality. Since wind conditions are not involved in the factory test, this method can accurately identify significant angle changes and promptly notify personnel for inspection. Furthermore, this method does not trigger the fault triggering conditions of existing proximity switches; specifically, no fault is triggered during no-load operation, ensuring the smooth progress of the no-load process.

[0142] In another example, real-time monitoring during unit operation can also be achieved, with fault early warning function, to avoid serious failures in the pitch system, which is of great significance and effect on the safe operation of wind turbines.

[0143] Furthermore, the anomaly detection method according to the embodiments of this disclosure can automatically eliminate interference caused by bearing vibration. The reason is that the oscillation of the wind turbine blades is often an alternating oscillation in two directions. For the stop on the installed pitch bearing, the result is that the angle is once smaller than the initial angle and once larger than the initial angle. When the positive and negative values ​​are added together, the sum will approach 0.

[0144] According to a second aspect of an exemplary embodiment of the present disclosure, an abnormality detection system for a pitch limiting mechanism of an impeller system is provided, such as... Figure 11 As shown, the pitch limiting mechanism includes a proximity switch 1111 and a stop 1112, and the anomaly detection system includes a test platform 1121 and an angle measuring device 1122.

[0145] The test platform 1121 can control the impeller system to perform pitch control within a preset angle range including the pitch limit position, wherein the proximity switch 1111 can be set at the pitch limit position.

[0146] During the pitch control process of the impeller system, the angle measuring device 1122 can acquire the trigger angle data when the proximity switch 1111 is triggered. For example, the angle measuring device 1122 can be an encoder in the impeller system.

[0147] The test platform 1121 can detect whether the proximity switch and the stop are malfunctioning based on the difference between the trigger angle data and the preset angle data.

[0148] As an example, the anomaly detection system could have the features shown above. Figure 5 The topology shown can perform corresponding operations or functions, and the specific ways in which each device performs the operation have been described in detail in the embodiments of the method, and will not be elaborated here.

[0149] According to a third aspect of the embodiments of this disclosure, a computer-readable storage medium is provided. Specifically, an anomaly detection method for a pitch limiting mechanism of an impeller system according to embodiments of this disclosure can be programmed into a computer program and stored on a computer-readable storage medium. When the instructions in the computer-readable storage medium are executed by at least one processor, the at least one processor is caused to perform the anomaly detection method for the pitch limiting mechanism of an impeller system according to exemplary embodiments of this disclosure. Examples of computer-readable storage media include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disc storage, hard disk drive (HDD), solid-state drive (SSD), card storage (such as multimedia cards, secure digital (SD) cards, or ultra-fast digital (XD) cards), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, and any other device configured to store a computer program and any associated data, data files, and data structures in a non-transitory manner and to provide the computer program and any associated data, data files, and data structures to a processor or computer so that the processor or computer can execute the computer program. In one example, the computer program and any associated data, data files, and data structures are distributed across a networked computer system, such that the computer program and any associated data, data files, and data structures are stored, accessed, and executed in a distributed manner through one or more processors or computers.

[0150] Furthermore, the abnormal detection method for the pitch limiting mechanism of the impeller system according to the embodiments of this disclosure can be implemented on an electronic device. Specifically, the electronic device includes: at least one processor; at least one memory storing processor-executable instructions, wherein the processor-executable instructions, when executed by the at least one processor, cause the at least one processor to execute the abnormal detection method for the pitch limiting mechanism of the impeller system according to the embodiments of this disclosure.

[0151] As an example, an electronic device can be a PC, tablet, personal digital assistant, smartphone, or other device capable of executing the aforementioned set of instructions. Here, the electronic device is not necessarily a single device; it can be any collection of devices or circuits capable of executing the aforementioned instructions (or instruction sets) individually or in combination. The electronic device can also be part of an integrated control system or system manager, or can be configured to interconnect locally or remotely (e.g., via wireless transmission) through an interface.

[0152] In electronic devices, a processor may include a central processing unit (CPU), a graphics processing unit (GPU), a programmable logic device, a dedicated processor system, a microcontroller, or a microprocessor. By way of example and not limitation, a processor may also include analog processors, digital processors, microprocessors, multi-core processors, processor arrays, network processors, etc.

[0153] The processor can execute instructions or code stored in memory, which can also store data. Instructions and data can also be sent and received over a network via a network interface device, which can employ any known transport protocol.

[0154] Memory can be integrated with the processor; for example, RAM or flash memory can be housed within an integrated circuit microprocessor. Alternatively, memory can comprise a separate device, such as an external disk drive, storage array, or other storage device that can be used by any database system. Memory and processor can be operatively coupled, or can communicate with each other, for example, via I / O ports, network connections, etc., enabling the processor to read files stored in the memory.

[0155] In addition, electronic devices may include video displays (such as liquid crystal displays) and user interaction interfaces (such as keyboards, mice, touch input devices, etc.). All components of the electronic device may be interconnected via buses and / or networks.

[0156] According to embodiments of the present disclosure, a computer program product is also provided, which includes computer instructions that, when executed by a processor, can implement an anomaly detection method for the pitch limiting mechanism of an impeller system according to embodiments of the present disclosure.

[0157] The specific embodiments of this disclosure have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that modifications and variations can be made to these embodiments without departing from the principles and spirit of this disclosure, which are defined by the claims and their equivalents. Such modifications and variations should also be within the protection scope of the claims of this disclosure.

Claims

1. A method for detecting anomalies in a pitch limiting mechanism of an impeller system, wherein the pitch limiting mechanism includes a proximity switch and a stop, characterized in that, The anomaly detection method includes: The impeller system is controlled to perform pitch control within a preset angle range including the pitch limit position, wherein the proximity switch is located at the pitch limit position; During the process of the impeller system performing pitching action, the trigger angle data when the proximity switch is triggered is acquired. The triggering of the proximity switch includes the proximity switch sensing the approach of the stop and the proximity switch sensing the disengagement of the stop. Based on the difference between the trigger angle data and the preset angle data, the system detects whether the pitch limiting mechanism has malfunctioned. The impeller system performs multiple reciprocating pitch maneuvers within the preset angle range. The preset angle data is the initial angle data when the proximity switch is first triggered during the multiple reciprocating pitch maneuvers. The abnormality of the pitch limiting mechanism is detected by accumulating the single-trip angle difference in the multiple round-trip pitch movements. The single-trip angle difference is the angle difference between the trigger angle data and the preset angle data in each round-trip pitch movement after the proximity switch is first triggered.

2. The anomaly detection method according to claim 1, characterized in that, The step of detecting whether the pitch limiting mechanism is malfunctioning based on the difference between the trigger angle data and the preset angle data includes: Based on the single-trip angle difference, a statistical value of the single-trip angle difference is determined in the multiple round-trip pitching actions, wherein the statistical value is the sum of the single-trip angle differences or the sum of the absolute values ​​of the single-trip angle differences. In response to the statistical value being greater than a preset threshold, it is determined that the pitch limiting mechanism has malfunctioned.

3. The anomaly detection method according to claim 1, characterized in that, The anomaly detection method is performed when the impeller system is without blades installed. The step of controlling the impeller system to perform pitch control within a preset angle range including the pitch limit position includes: controlling the impeller system to perform pitch control within the preset angle range through a test platform.

4. The anomaly detection method according to claim 3, characterized in that, The step of controlling the impeller system to perform pitching action within a preset angle range including the pitch limit position includes: During the pitch control maneuver, the test platform sends a speed switching command to the pitch controller of the impeller system, causing the pitch controller to control the impeller system to switch between different pitch speeds to perform the pitch control maneuver according to the speed switching command. When the stop block is within a preset angular distance from the proximity switch, the test platform controls the impeller system to switch the pitch speed.

5. The anomaly detection method according to claim 4, characterized in that, The speed switching command includes the pitch speed to be switched to, wherein the pitch speed to be switched to is greater than the current pitch speed. The step of the test platform sending a speed switching command to the pitch controller of the impeller system during the pitch control operation, so that the pitch controller controls the impeller system to switch to different pitch speeds to perform the pitch control operation according to the speed switching command, includes: During the pitch control operation, in response to the pitch duration at the current pitch speed reaching a first duration, the test platform sends the speed switching command to the pitch controller, causing the pitch controller to control the impeller system to switch from the current pitch speed to the pitch speed to be switched, so that the stop block generates acceleration before reaching the proximity switch.

6. The anomaly detection method according to claim 2, characterized in that, The preset threshold is greater than the difference threshold corresponding to a single pitching action, and less than the product of the number of round-trip pitching actions and the difference threshold.

7. The anomaly detection method according to claim 1 or 2, characterized in that, The anomaly detection method is performed during the operation of the wind turbine generator set. The step of controlling the rotor system to perform pitch control within a preset angle range, including the pitch limit position, includes: At rated wind speed or under limited power operation, the control system of the wind turbine generator set controls the rotor system to perform pitch control within the preset angle range.

8. The anomaly detection method according to claim 7, characterized in that, The trigger angle data is acquired through the angle measuring device of the impeller system, wherein the anomaly detection method further includes: In response to the proximity switch being triggered during a non-first reciprocating pitch maneuver, the sensing value of the angle measuring device of the impeller system is acquired; Based on the difference between the sensed value and the preset angle data, the angle measuring device is used for fault detection.

9. An anomaly detection system for a pitch limiting mechanism of an impeller system, the pitch limiting mechanism comprising a proximity switch and a stop, characterized in that, The anomaly detection system includes a test platform and an angle measuring device. The test platform controls the impeller system to perform pitch control within a preset angle range including the pitch limit position, wherein the proximity switch is located at the pitch limit position; During the process of the impeller system performing pitch control, the angle measuring device acquires the trigger angle data when the proximity switch is triggered. The triggering of the proximity switch includes induction triggering when the proximity switch senses the approach of the stop and disengagement triggering when the proximity switch senses the disengagement of the stop. The testing platform detects whether the pitch limiting mechanism is malfunctioning based on the difference between the trigger angle data and the preset angle data. The impeller system performs multiple reciprocating pitch maneuvers within the preset angle range. The preset angle data is the initial angle data when the proximity switch is first triggered during the multiple reciprocating pitch maneuvers. The abnormality of the pitch limiting mechanism is detected by accumulating the single-trip angle difference in the multiple round-trip pitch movements. The single-trip angle difference is the angle difference between the trigger angle data and the preset angle data in each round-trip pitch movement after the proximity switch is first triggered.

10. A computer-readable storage medium, characterized in that, When the instructions in the computer-readable storage medium are executed by at least one processor, the at least one processor causes the processor to perform the abnormal detection method of the pitch limit mechanism of the impeller system as described in any one of claims 1-8.

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