Fault detection method, device and equipment of variable pitch system and readable storage medium

Abstract

The application discloses a fault detection method, device and equipment of a variable pitch system, and a readable storage medium. The variable pitch system can obtain a blade angle and a reference angle when a proximity switch is triggered, compare the blade angle with the reference angle, update forward counting data and / or negative counting data corresponding to the proximity switch according to a comparison result, and determine a fault type of the variable pitch system according to the updated forward counting data and negative counting data. According to the application, the blade angle and the reference angle when the proximity switch is triggered are used for fault detection, compared with fault detection according to a switch signal of the proximity switch, the problem that fault detection is not timely due to signal delay is avoided, and the application only needs to use two counting data to complete fault detection of the variable pitch system, so that the detection method is simple and reliable, and complex model operation is not needed.

Description

Technical Field

[0001] This application belongs to the field of wind power generation technology, and in particular relates to a method, device, equipment and readable storage medium for fault detection of pitch system. Background Technology

[0002] 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. During wind turbine generator operation, the pitch system can determine whether there is a fault in the wind turbine generator by judging whether the actual position of the blades has reached the expected position, thus ensuring the safe use of the blades and the stable operation of the unit.

[0003] Currently, the common fault detection method for pitch systems using toothed belt drives involves installing two proximity switches and a stop block to trigger them within the system. One proximity switch is located at the feathering stop angle, and the other at the generator angle. Taking the proximity switch at the generator angle as an example, the fault detection method is as follows: when the pitch motor angle measured by the main encoder of the pitch system is near the generator angle position, if the proximity switch at the generator angle position is triggered, it indicates no fault; if the proximity switch at the generator angle position is not triggered, it indicates a fault.

[0004] While the aforementioned fault detection method can detect faults in the pitch system, it suffers from a delay due to the proximity switch outputting a switching signal, which is susceptible to interference from filtered signals. Therefore, if a proximity switch or stop becomes loose, the pitch system will only detect the fault if the duration of the resulting malfunction exceeds this delay. Furthermore, the fault cannot be detected in its early stages of loosening. Thus, existing fault detection methods fail to identify early-stage faults, necessitating a new fault detection method. Summary of the Invention

[0005] This application provides a fault detection method, apparatus, device, and readable storage medium for a pitch system. It can detect faults based on the blade angle when a proximity switch is triggered, which avoids the problem of untimely fault detection due to signal delay compared to fault detection based on the switching signal of the proximity switch.

[0006] In a first aspect, embodiments of this application provide a fault detection method for a pitch system, the pitch system including a toothed belt, a proximity switch, and a stop for triggering the proximity switch, the method including:

[0007] Obtain the blade angle and reference angle when the target proximity switch is triggered;

[0008] Compare the blade angle with the reference angle, and update the positive and / or negative count data corresponding to the target proximity switch based on the comparison results;

[0009] Based on the updated positive and negative count data, the type of fault that occurred in the pitch system is determined.

[0010] As one possible implementation, obtaining the reference angle when the target proximity switch is triggered includes:

[0011] If it is determined that the target proximity switch is being triggered for the first time, a preset angle is obtained as the reference angle when the target proximity switch is triggered.

[0012] If it is determined that the target proximity switch is not being triggered for the first time, the blade angle when the target proximity switch was previously triggered is obtained as the reference angle when the target proximity switch is triggered.

[0013] As one possible implementation, the positive and / or negative count data corresponding to the target proximity switch are updated based on the comparison result, including:

[0014] If the comparison result shows that the blade angle is greater than the reference angle, increment the positive count data corresponding to the target proximity switch by one;

[0015] If the comparison result shows that the blade angle is less than the reference angle, the negative count data corresponding to the target proximity switch is incremented by one.

[0016] As one possible implementation, the type of fault occurring in the pitch system is determined based on the updated positive and negative count data, including:

[0017] If both the updated positive and negative count data are greater than or equal to the first threshold, it is determined that the target proximity switch has a loosening fault and / or the stop has a loosening fault.

[0018] As one possible implementation, the type of fault occurring in the pitch system is determined based on the updated positive and negative count data, including:

[0019] If both the updated positive and negative count data are greater than 0 and less than the first threshold, it is determined that the toothed belt has a loosening fault.

[0020] As one possible approach, methods for determining before a loosening failure occurs in the toothed belt also include:

[0021] Determine the first time taken from when both the positive and negative count data are 0 to when both the positive and negative count data are less than the first threshold;

[0022] Compare the magnitude of the first time point with the time threshold;

[0023] Determining that the toothed belt is loose includes:

[0024] If the first time is greater than or equal to the time threshold, it is determined that the toothed belt has loosened.

[0025] As one possible approach, methods for determining before a loosening failure occurs in the toothed belt also include:

[0026] Determine the target difference between the blade angle and the reference angle when the target proximity switch is triggered;

[0027] Compare the target difference with the angle threshold.

[0028] Determining that the toothed belt is loose includes:

[0029] If the target difference is greater than or equal to the angle threshold, it is determined that the toothed belt has become loose.

[0030] As one possible implementation, the type of fault occurring in the pitch system is determined based on the updated positive and negative count data, including:

[0031] If the updated negative count data is 0 and the positive count data is greater than or equal to the second threshold, it is determined that the toothed belt has broken.

[0032] As one possible implementation, before obtaining the blade angle when the target proximity switch is triggered and the reference angle of the target proximity switch, the method further includes:

[0033] When the pitch system is started, the reference angle, positive count data, and negative count data corresponding to the target proximity switch are initialized.

[0034] Secondly, embodiments of this application provide a fault detection device for a pitch system. The pitch system includes a toothed belt, a proximity switch, and a stop for triggering the proximity switch. The fault detection device includes:

[0035] The acquisition unit is used to acquire the blade angle and reference angle when the target proximity switch is triggered.

[0036] The comparison unit is used to compare the size of the blade angle with the reference angle.

[0037] The update unit is used to update the positive and / or negative count data corresponding to the target proximity switch based on the comparison result between the blade angle and the reference angle.

[0038] The fault determination unit is used to determine the type of fault that has occurred in the pitch system based on the updated positive and negative count data.

[0039] Thirdly, embodiments of this application provide a wind turbine generator, including: a pitch system and a fault detection device for the pitch system in the second aspect;

[0040] The pitch system includes a proximity switch, a stop for triggering the proximity switch, and a toothed belt.

[0041] Fourthly, embodiments of this application provide a fault detection device for a pitch system, the device comprising: a processor and a memory storing computer program instructions;

[0042] The processor executes computer program instructions to implement a fault detection method for the pitch system as described in the first aspect.

[0043] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the fault detection method for the pitch system as described in the first aspect.

[0044] In a sixth aspect, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform a fault detection method for a pitch system as described in the first aspect.

[0045] The pitch system fault detection method, apparatus, device, and readable storage medium of this application embodiment can acquire the blade angle and reference angle when the proximity switch in the pitch system is triggered, compare the size of the blade angle and the reference angle, and update the positive and / or negative count data corresponding to the proximity switch according to the comparison result. Based on the updated positive and negative count data, the fault type of the pitch system is determined. According to the embodiments of this application, fault detection is performed based on the blade angle and reference angle when the proximity switch is triggered. Compared with fault detection based on the switching signal of the proximity switch, this avoids the problem of untimely fault detection due to signal delay. Moreover, this application only needs two count data to complete the detection of pitch system faults. The detection method is simple and reliable, and does not require complex model calculations. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1This application is a structural diagram of the pitch system provided by Shiliba.

[0048] Figure 2 This is a flowchart illustrating a fault detection method for a pitch system provided in one embodiment of this application;

[0049] Figure 3 This is a flowchart illustrating a fault detection method for a pitch system provided in another embodiment of this application;

[0050] Figure 4 This is a waveform diagram of a toothed belt fracture failure provided in one embodiment of this application;

[0051] Figure 5 This is a waveform diagram of a loose device fault provided in one embodiment of this application;

[0052] Figure 6 This is a comparison diagram of the triggering timing of a three-bladed target proximity switch provided in one embodiment of this application;

[0053] Figure 7 This is a schematic diagram of the structure of a fault detection device for a pitch system provided in another embodiment of this application;

[0054] Figure 8 This is a schematic diagram of the structure of a fault detection device for a pitch system provided in another embodiment of this application. Detailed Implementation

[0055] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0057] Wind power generation systems typically consist of multiple blades, each with its own independent pitch control system.

[0058] The structure of a pitch system using toothed belt drive is described below.

[0059] To facilitate understanding, before introducing the structure of the pitch system, we will first explain the technical terms that may be involved.

[0060] Toothed belts are a new type of closed transmission belt with a toothed structure on the working surface. They transmit motion and power by meshing with belt teeth and pulley teeth. Toothed belts are widely used in mechanical belt drives and have the characteristics of simple structure, smooth transmission, shock absorption, no need for lubrication, and easy maintenance.

[0061] A tension wheel is a tensioning device for belt drives. When the center distance of the belt cannot be adjusted, a tension wheel can be used to tension the belt. At the same time, to ensure that the wrap angle of the smaller pulley does not decrease excessively, the tension wheel should be installed as close as possible to the larger pulley.

[0062] Pitch angle, also known as pitch control angle, refers to the angle between the wind turbine blades and the rotor plane. Wind turbines use variable pitch control, adjusting the blade angle to regulate power output. The main purposes of adjusting the pitch angle of a wind turbine include: obtaining a larger starting torque under wind force to drive the turbine rotor and start the generator; limiting power output to stabilize power after reaching rated wind speed, protecting mechanical and electrical systems, and reducing load; and implementing pneumatic braking when retracting the blades to quickly reduce rotor speed and avoid damage caused by excessive inertial forces from mechanical braking.

[0063] 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 proximity switch and enters the operating distance of the proximity switch, the proximity switch can be activated without mechanical contact or the application of any pressure. It has the characteristics of limit switches and micro switches, and also features reliable operation, stable performance, fast frequency response, and strong anti-interference ability.

[0064] See Figure 1 This is a schematic diagram of a pitch system using a toothed belt drive, as shown below. Figure 1 As shown, the pitch system includes a reducer 101, a drive wheel 102, a tension wheel 103, a tension wheel 104, a hub 105, a toothed belt 106, a blade mounting device 107 (specifically referring to the pitch bearing and the components connected and fixed to the pitch bearing), a toothed belt fixing block 108, a toothed belt fixing block 109, a tension wheel fixing device 110, a first proximity switch 112 located at the generator angle position, a second proximity switch 112 located at the feathering stop angle position, and a stop block 113. The generator angle and the feathering stop angle are usually determined according to the aircraft model. The following explanation will take a generator angle of 5° and a feathering stop angle of 87° as an example.

[0065] The reducer 101 meshes with the pitch motor (not shown in the figure); the drive wheel 102 is mechanically connected to the output shaft of the reducer 101; the reducer 101 and the tensioner fixing device 110 are both fixedly mounted on the hub 105; the tensioner fixing device 110 is used to install the tensioner 103 and tensioner 104; the tensioner 103 and tensioner 104 are used to tension the toothed belt 106 to ensure the reliability of the transmission; the first proximity switch 111 and the second proximity switch 112 are mounted on the hub 105. The first proximity switch 111 is installed at the 5-degree position of the blade, and the second proximity switch 112 is installed at the 87-degree position of the blade. The stop block 113 is installed on the blade mounting device 107 and rotates with the blade mounting device 107. During normal operation, when the stop block 113 rotates to the position of the first proximity switch 111, that is, the 5-degree position, the first proximity switch 111 is triggered. When the stop block 113 rotates to the position of the second proximity switch 112, that is, the 87-degree position, the second proximity switch 112 is triggered.

[0066] The blade mounting device 107 is a circular mechanical mechanism used to mount blades; the toothed belt 106 runs along the side of the blade mounting device 107 and is in close contact with the side of the blade mounting device 107 to provide power for transmission; the toothed belt fixing block 109 and the tension wheel fixing device 110 are used to fix the toothed belt 106 to the blade mounting device 107.

[0067] The working principle of the above-mentioned pitch system is as follows: the blade position is detected, and when it is determined that pitch adjustment is required, that is, when the blade pitch angle needs to be changed, the pitch motor (not shown in the figure) drives the reducer 101 to rotate. The reducer 101 drives the transmission wheel 102 to rotate. When the transmission wheel 102 rotates, it drives the toothed belt 106 to move. The toothed belt 106 drives the blade mounting device 107 to rotate, thereby changing the angle of the wind turbine blade and thus achieving the purpose of adjusting the pitch angle.

[0068] Because the transmission method of this pitch system uses toothed belts and gears to transmit motion and power, rather than gears, it is generally difficult to detect the actual angle of the blades. Usually, only the angle of the main encoder located at the tail of the pitch motor can be detected as the blade angle, while the blade position is generally detected using stops and proximity switches.

[0069] Currently, the main method for fault detection in the aforementioned pitch system is to determine whether a fault has occurred by judging whether the actual position of the blades has reached the expected position. This mainly includes: when the angle value measured by the main encoder is around 5 degrees, the signal of the first proximity switch at the 5-degree position is detected to determine whether the first proximity switch has been triggered. If no signal of the first proximity switch is detected, it is considered that the first proximity switch has not been triggered, thereby determining that there is a fault in the pitch system. In order to avoid the damage caused by the fault, the wind turbine is controlled to feather and shut down.

[0070] While the above method can detect faults in pitch control systems, it primarily relies on detecting proximity switch signals. These signals are switching signals, which are typically affected by interference from filtered signals, resulting in a detection delay (usually 180ms to 300ms). Therefore, faults can only be detected if their duration exceeds this delay. This leads to the following shortcomings in the current method:

[0071] First, early loosening faults in devices such as proximity switches or stops cannot be detected. This is because device loosening usually doesn't happen suddenly but rather through a process. For example, if each fault condition lasts only 100ms, and the fault trigger duration (i.e., the delay time) is not reached, it will not be detected. However, after a device becomes loose, the loosening will worsen over long-term operation, eventually leading to a fault. If a proximity switch is loose, it may eventually trigger a shutdown of the wind turbine. If a stop is loose, it may prevent the pitch system from stopping when the pitch is retracted, as the second proximity switch at 87 degrees cannot be triggered, causing the pitch motor to continue rotating. This could lead to the toothed belt breaking and damaging the fixing mechanical parts of the toothed belt, resulting in significant damage.

[0072] Secondly, the detection accuracy is low. The reason is that the proximity switch's signal is interrupted for a short time, which may be due to foreign objects blocking the signal or vibration, or it may be due to the encoder's occasional jump. It is not necessarily caused by the proximity switch or the stop block being loose.

[0073] Thirdly, since the main encoder actually detects the angle of the pitch motor, the above method cannot detect toothed belt breakage faults. Generally, manual inspection is required to find them. However, toothed belt breakage is a relatively serious fault, so detection or alarm for toothed belt breakage is also very necessary.

[0074] To address the aforementioned issues, this application provides a fault detection method, apparatus, device, and readable storage medium for pitch systems, applicable to scenarios involving fault detection in the pitch systems of wind turbine generators. This application utilizes the operational characteristics of the pitch system during startup, shutdown, and pitch adjustment to continuously assess the blade angle when a proximity switch is triggered, thereby detecting whether the proximity switch or stop has become loose. Compared to detection methods using proximity switch signals, this application can promptly detect situations such as loose proximity switches or stops, preventing further aggravation of the loosening. This avoids wind turbine generator-triggered faults and prevents the toothed belt from breaking or mechanical components from being damaged due to loose stops.

[0075] The fault detection method for the pitch system provided in the embodiments of this application will be described below.

[0076] See Figure 2 This is a flowchart illustrating a fault detection method for a pitch system provided in an embodiment of this application. Figure 2 As shown, the fault detection method for a pitch system provided in this application embodiment may include the following steps:

[0077] S21. Obtain the blade angle and reference angle when the target proximity switch is triggered.

[0078] In this embodiment, the target proximity switch can be a proximity switch at the power generation angle in the pitch system.

[0079] S22. Compare the blade angle with the reference angle, and update the positive and / or negative count data corresponding to the proximity switch based on the comparison result.

[0080] S23. Based on the updated positive and negative count data, determine the type of fault that occurred in the pitch system.

[0081] The fault detection method for a pitch system according to this application embodiment obtains the blade angle and reference angle when a proximity switch in the pitch system is triggered, compares the blade angle with the reference angle, and updates the positive and / or negative count data corresponding to the proximity switch based on the comparison result. Based on the updated positive and negative count data, the fault type of the pitch system is determined. According to this application embodiment, fault detection is performed based on the blade angle and reference angle when the proximity switch is triggered. Compared to fault detection based on the proximity switch signal, this avoids the problem of untimely fault detection due to signal delay. Moreover, this application only needs two count data points to complete the detection of pitch system faults, making the detection method simple, reliable, and requiring no complex model calculations.

[0082] Furthermore, the embodiments of this application also avoid fault misjudgment caused by signal interruption of the proximity switch due to foreign objects or vibration when performing fault detection based on the proximity switch signal, thereby improving the accuracy of fault detection.

[0083] The specific implementation methods for each of the above steps are described below.

[0084] First, let's introduce S21. In this embodiment of the application, after the pitch system is started, the blade angle and reference angle at the time the target proximity switch is triggered can be obtained every time the target proximity switch is detected to be triggered.

[0085] The blade angle refers to the angle of the blades installed on the pitch system. When obtaining the blade angle when the target proximity switch is triggered, the angle measured by the main encoder located at the tail of the pitch motor can be obtained and used as the blade angle.

[0086] In this embodiment, when obtaining the reference angle when the target proximity switch is triggered, it can first be determined whether the triggering of the target proximity switch is the first triggering of the target proximity switch after the pitch motor starts. If it is determined to be the first triggering, a preset angle can be obtained as the reference angle of the target proximity switch. If it is determined not to be the first triggering, the blade angle when the target proximity switch was previously triggered can be obtained as the reference angle of the target proximity switch. The preset angle can be set before the pitch motor starts.

[0087] In this way, the reference angle of the target proximity switch can be dynamically updated.

[0088] In one example, the preset angle can be set according to the initial triggering range of the target proximity switch. For example, the upper limit of the initial triggering range of the target proximity switch can be used as the preset angle. The initial triggering range of the target proximity switch is typically a set value based on the model of the wind turbine and the installation location of the target proximity switch. In this embodiment, the target proximity switch is located at the power generation angle position; if the power generation angle is 5°, then the initial angle can be 5°.

[0089] The above describes the implementation of S21. The following describes the implementation of S22.

[0090] In S22, positive count data is used to record cases where the blade angle is greater than the reference angle, and negative count data is used to record cases where the blade angle is less than the reference angle.

[0091] In one example, a positive counter and a negative counter can be pre-set. The positive counter records positive count data, and the negative counter records negative count data. Based on this, when updating the positive and / or negative count data corresponding to the target proximity switch according to the comparison result of the blade angle and the reference angle, the positive count data corresponding to the target proximity switch can be incremented by 1 if the comparison result is that the blade angle is greater than the reference angle, and the negative count data corresponding to the target proximity switch can be incremented by 1 if the comparison result is that the blade angle is less than the reference angle.

[0092] As can be seen from the implementation of S21 above, the reference angle of the target proximity switch is dynamically updated. When the target proximity switch is not being triggered for the first time, the obtained reference angle is actually the blade angle at the time of the previous trigger. Therefore, in this embodiment, apart from the initial trigger of the target proximity switch, each subsequent trigger compares the blade angle at the time of triggering with the blade angle at the time of the previous trigger, and then updates the positive or negative count data based on the comparison result. Thus, the positive and negative count data can reflect the changing trend of the blade angle at the time the target proximity switch is triggered.

[0093] The above describes the implementation of S22. The following describes the implementation of S23.

[0094] In this embodiment, S23 can be executed once after each update of positive or negative count data is completed, or S23 can be executed once at a preset time interval after the pitch system is started. The preset time interval can be set according to the actual situation, such as 1 hour or 2 hours.

[0095] When determining the fault type of the pitch system based on the updated positive and negative count data, it can be determined whether the updated positive and negative count data meet any of the following three conditions, and the fault type of the pitch system can be determined based on the determination result:

[0096] The first scenario: Both the updated positive and negative count data are relatively large.

[0097] The second scenario: Both the updated positive and negative count data are greater than 0, but both are relatively small.

[0098] The third scenario: The updated negative or positive count data is not 0 and is relatively large, and the blade angle increases.

[0099] The above three situations can be judged in parallel. Parallel judgment can improve judgment efficiency, thereby improving fault detection efficiency.

[0100] The three scenarios described above can also be evaluated according to a preset order, which can be set based on the actual situation. For example, the evaluation order could be: first, check if the first scenario is met; if not, then check if the third scenario is met; and if not, then check if the second scenario is met. By evaluating according to this order, once one scenario is determined to be met, there is no need to evaluate the others, thus reducing the computational load required for evaluation.

[0101] In one example, when determining whether the updated positive and negative count data meet the first condition, both the positive and negative count data can be compared with a first threshold. If both the positive and negative count data are greater than or equal to the first threshold, then the updated positive and negative count data meet the first condition; otherwise, the updated positive and negative count data do not meet the first condition. The first threshold can be set according to the actual situation, for example, it can be 4 or 5.

[0102] If the updated positive and negative count data match the first scenario, it can be determined that the target proximity switch and / or stop in the pitch system has a loosening fault. This is because if both the positive and negative count data are greater than or equal to the first threshold, it indicates that during operation, the position of the target proximity switch and / or stop changes repeatedly as the impeller rotates. This phenomenon is usually caused by a loose target proximity switch or stop; therefore, it can be determined that the target proximity switch and / or stop has become loose.

[0103] Furthermore, after determining that both the positive and negative count data are greater than or equal to the first threshold, to improve the accuracy of the detection results, it can be further determined whether the positive and negative count data are equivalent. If the positive and negative count data are determined to be equivalent, then it can be determined that the target proximity switch and / or stop is loose. For example, the difference between the positive and negative count data can be calculated. If the difference is less than a difference threshold, it is determined that they are equivalent; otherwise, they are determined to be inequitable. The difference threshold can be set according to actual needs.

[0104] In one example, when determining whether the updated positive and negative count data meet the second condition, both the positive and negative count data can be compared with 0 and the first threshold. If both the positive and negative count data are greater than 0 and less than the first threshold, then the updated positive and negative count data meet the second condition; otherwise, the updated positive and negative count data do not meet the second condition.

[0105] If the updated positive and negative count data are determined to match the second scenario, then it can be determined that a loose toothed belt fault has occurred in the pitch system.

[0106] Because during the process of both positive and negative count data becoming greater than or equal to the first threshold, there may be instances where both positive and negative count data are less than the first threshold. Therefore, to improve the detection accuracy of toothed belt loosening faults, after comparing the positive and negative count data to find that both are less than the first threshold, the first time taken from when both positive and negative count data are 0 to when both are found to be less than the first threshold is further determined. Then, the first time is compared with a time threshold. If the first time is greater than or equal to the time threshold, a toothed belt loosening fault is determined. The time threshold can be set according to actual conditions, for example, it can be 1 hour or 2 hours. This is because if the target proximity switch and / or stop is loose, the positive and negative count data will change within a short period of time. If the toothed belt is loose, it may take a long time to trigger a change in the counting data. For example, it may take 2 hours for the counting data to increase to 2. Therefore, this method can distinguish the loose toothed belt from the loose target proximity switch and / or stop, thereby improving the detection accuracy of the loose toothed belt fault.

[0107] To further improve the detection accuracy of toothed belt loosening faults, when both the positive count data and the negative calculation data are less than a first threshold, the target difference between the blade angle when the target proximity switch is triggered and the reference angle can be determined. Then, the target difference is compared with the angle threshold. If the target difference is greater than or equal to the angle threshold, a toothed belt loosening fault is determined in the pitch system. The angle threshold can be set according to actual conditions, for example, it can be 0.1°.

[0108] When determining the target difference between the blade angle and the reference angle when the target proximity switch is triggered, one can determine the difference between the blade angle and the reference angle each time the target proximity switch is triggered within the first time period, and then calculate the average of the differences, using the average as the target difference; alternatively, one can only calculate the difference between the blade angle and the reference angle when the target proximity switch is triggered for the last time within the first time period, and then use that difference as the target difference.

[0109] In one example, when determining whether the updated positive and negative count data meet the third condition, both can be compared to 0 and a second threshold. If the negative count data is 0 and the positive count data is not 0 and is greater than or equal to the second threshold, then the updated positive and negative count data meet the third condition. Otherwise, the updated positive and negative count data do not meet the third condition, because an increase in blade angle can only occur when the positive count data is not 0. The second threshold can be set according to actual needs and can be equal to the first threshold.

[0110] If the updated positive and negative count data match the third scenario, then a toothed belt breakage fault in the pitch system can be confirmed. This is because a negative count of 0 and a large positive count indicate that the target proximity switch was repeatedly triggered in one direction during pitch system operation. The large positive count also suggests that the blade angle was increasing when the proximity switch was triggered. This phenomenon is usually due to a broken toothed belt. After the toothed belt breaks, the motor continues to rotate normally, but the blades are no longer constrained by the motor and are in a free-swinging state. During this swinging process, the stop may trigger the target proximity switch, and the motor's rotation continuously increases the angle.

[0111] This method enables automatic detection of toothed belt fractures without the need for manual onboard inspection, facilitating timely fault detection and effectively reducing the adverse effects of such failures.

[0112] If, after judging the above three scenarios, the updated positive and negative count data do not conform to any of the three scenarios, then the pitch system is determined to be fault-free. For example, if the negative count data is 0 and the positive count data is not 0 but is less than the second threshold, then the pitch system is determined to be fault-free. This is because the preset initial angle is the upper limit trigger angle of the designed target proximity switch, and there will be some deviation during actual installation. Therefore, either the positive or negative count data will inevitably be counted once. Thus, if the positive count data is less than the second threshold, the pitch system is determined to be fault-free.

[0113] The above describes the implementation method of S23.

[0114] As another implementation of this application, in order to ensure the accuracy of fault detection, the following steps may be included before S21:

[0115] When the pitch system is started, the reference angle value, positive count data and negative count data corresponding to the target proximity switch are initialized.

[0116] Initializing the reference angle value can be done by setting the reference angle value to the initial angle, and initializing the positive and negative count data can be done by setting both the positive and negative count data to 0.

[0117] In one example, after the reference angle value, positive count data, and negative count data are initialized when the pitch system starts up, they are not initialized again during the operation of the pitch system until the next startup.

[0118] In another example, the reference angle value, positive count data, and negative count data can be initialized at preset intervals. The preset intervals can be set according to actual needs.

[0119] By initializing and resetting the reference angle of the target proximity switch and clearing the positive and negative count data to zero, the accuracy of fault detection results can be guaranteed.

[0120] See Figure 3 The above is a flowchart illustrating a fault detection method for a pitch system based on the implementation of the above steps. Figure 3 As shown, the fault detection method for the pitch system provided in this application mainly includes the following steps:

[0121] S301. Set the reference angle, positive count data, and negative count data of the target proximity switch.

[0122] S302. Check if the wind turbine generator set is started. If it is started, proceed to S303. If it is not started, end the process.

[0123] S303. Clear the positive and negative count data, initialize the reference angle, and prepare to detect the operating status of the pitch system.

[0124] S304. Determine whether the target proximity switch has been triggered. If it has been triggered, proceed to S305. If it has not been triggered, end the process.

[0125] S305. Determine whether the blade angle is greater than or less than the reference angle. If it is greater, proceed to S306; if it is less, proceed to S307.

[0126] S306. Increment the positive count data by 1, and then execute S308.

[0127] S307. Increment the negative count data by 1, and execute S308.

[0128] S308. Update reference angle.

[0129] S309. Determine whether the bidirectional counting data are both large and equivalent. If yes, proceed to S310; otherwise, proceed to S311. Here, bidirectional counting data refers to both positive and negative counting data.

[0130] S310. Determine that the target proximity switch and / or stop is loose.

[0131] S311. Determine whether the unidirectional count data is not 0 and the blade angle increases. If yes, execute S312; otherwise, execute S313.

[0132] S312. It is determined that the toothed belt has broken.

[0133] S313. Determine whether the bidirectional counting data are all greater than 0 and smaller. If yes, execute S314; otherwise, end.

[0134] S314. Determine if the toothed belt is loose.

[0135] The following describes the fault detection method for the pitch system provided in the embodiments of this application with specific examples.

[0136] Referring to Table 1, these are the positive and negative count data recorded when performing fault detection on the pitch systems of shafts 1, 2, and 3 of a wind turbine using the fault detection method provided in this application embodiment. Each shaft corresponds to one blade. In the table, L represents the negative count data corresponding to the target proximity switch, and R represents the positive count data corresponding to the target proximity switch.

[0137] Table 1

[0138]

[0139] Referring to row 1 of Table 1, L is 0 and R is 4 for shaft 2. This indicates that the toothed belt of the pitch system corresponding to shaft 2 has broken. The waveform diagram for this fault can be found in [reference needed]. Figure 3 .

[0140] Figure 4 In the diagram, the first curve represents the blade angle value, and the second curve represents the signal from the target proximity switch. From... Figure 4 As can be seen, the target proximity switch was triggered multiple times in succession, and the blade angle value was relatively large, which indicates that the toothed belt broke, causing the stop block to rotate freely with the blade, resulting in abnormal triggering of the target proximity switch.

[0141] Referring to row 3 of Table 1, the values ​​of L and R for all three axes are relatively small, which indicates that the pitch systems corresponding to each of the three axes are functioning normally.

[0142] Referring to row 4 of Table 1, the L and R values ​​for shaft 3 are both relatively large. This indicates that the target proximity switch or stop in the pitch system corresponding to shaft 3 has become somewhat loose. The waveform diagram for this fault is shown below. Figure 4 As shown.

[0143] Figure 5 In the diagram, the first curve represents the blade angle value, the second curve represents the signal from the target proximity switch, and the black line represents the coordinate markers. From Figure 5 As can be seen, the blade angle value is inconsistent each time the proximity switch is triggered, which indicates that the target proximity switch or the stop has become loose, causing the blade angle value to change to different degrees each time the target proximity switch reaches the position of the stop.

[0144] See Figure 6 ,for Figure 5 The diagram shows a comparison of the triggering timing of the target proximity switches on the three blades under the corresponding fault conditions. The first curve represents the signal of the target proximity switch on the faulty axis. As can be seen from the diagram, the triggering timing of the target proximity switch on the first curve is different from that of the target proximity switches on the other two blades in both triggering events. The triggering timing on the left is earlier, and the triggering timing on the right is to the right.

[0145] Based on the fault detection method for the pitch system provided in the above embodiments, this application also provides a specific implementation of a fault detection device for the pitch system. Please refer to the following embodiments.

[0146] See Figure 7 This is a schematic diagram of the structure of a fault detection device for a pitch system provided in an embodiment of this application, as shown below. Figure 7As shown, the fault detection device for the pitch system provided in this application embodiment may include the following units:

[0147] The acquisition unit 701 is used to acquire the blade angle and reference angle when the target proximity switch is triggered.

[0148] Comparison unit 702 is used to compare the size of the blade angle and the reference angle.

[0149] The update unit 703 is used to update the positive and / or negative count data corresponding to the target proximity switch based on the comparison result between the blade angle and the reference angle.

[0150] The fault determination unit 704 is used to determine the type of fault that has occurred in the pitch system based on the updated positive and negative count data.

[0151] The fault detection device for the pitch system in this application embodiment can acquire the blade angle and reference angle when the proximity switch in the pitch system is triggered, compare the size of the blade angle and the reference angle, and update the positive and / or negative count data corresponding to the proximity switch based on the comparison result. Based on the updated positive and negative count data, the fault type of the pitch system is determined. According to this application embodiment, fault detection is performed based on the blade angle and reference angle when the proximity switch is triggered. Compared with fault detection based on the switching signal of the proximity switch, this avoids the problem of untimely fault detection due to signal delay. Moreover, this application only needs two count data to complete the detection of pitch system faults, making the detection method simple, reliable, and requiring no complex model calculations.

[0152] As one possible implementation, the acquisition unit 701 is used for:

[0153] If it is determined that the target proximity switch is being triggered for the first time, a preset angle is obtained as the reference angle when the target proximity switch is triggered.

[0154] If it is determined that the target proximity switch is not being triggered for the first time, the blade angle when the target proximity switch was previously triggered is obtained as the reference angle when the target proximity switch is triggered.

[0155] As one possible implementation, update unit 703 is used for:

[0156] If the comparison result shows that the blade angle is greater than the reference angle, increment the positive count data corresponding to the target proximity switch by one;

[0157] If the comparison result shows that the blade angle is less than the reference angle, the negative count data corresponding to the target proximity switch is incremented by one.

[0158] As one possible implementation, the fault determination unit 704 is used for:

[0159] If both the updated positive and negative count data are greater than or equal to the first threshold, it is determined that the target proximity switch has a loosening fault and / or the stop has a loosening fault.

[0160] As one possible implementation, the fault determination unit 704 is used for:

[0161] If both the updated positive and negative count data are less than the first threshold, it is determined that the toothed belt has a loosening fault.

[0162] As one possible implementation, the fault determination unit 704 is also used for:

[0163] Before determining that the toothed belt has loosened, determine the first time taken from when both the positive and negative count data are 0 to when both the positive and negative count data are less than the first threshold.

[0164] Compare the magnitude of the first time point with the time threshold;

[0165] If the first time is greater than or equal to the time threshold, it is determined that the toothed belt has loosened.

[0166] As one possible implementation, the fault determination unit 704 is also used for:

[0167] Before determining that the toothed belt has become loose, determine the target difference between the blade angle and the reference angle when the target proximity switch is triggered;

[0168] Compare the target difference with the angle threshold.

[0169] If the target difference is greater than or equal to the angle threshold, it is determined that the toothed belt in the pitch system has a loosening fault.

[0170] As one possible implementation, the fault determination unit 704 is used for:

[0171] If the updated negative count data is 0 and the positive count data is greater than or equal to the second threshold, it is determined that the toothed belt in the pitch system has broken.

[0172] As one possible implementation, the device may also include an initialization unit ( Figure 7 (not shown in the image);

[0173] The initialization unit is used to initialize the reference angle, positive count data, and negative count data corresponding to the target proximity switch before acquiring the blade angle when the target proximity switch is triggered and the reference angle of the target proximity switch when the pitch system is started.

[0174] This application also provides a specific implementation of a wind turbine generator. The wind turbine generator provided in this application includes a pitch control system and a fault detection device for the pitch control system provided in the above embodiments, wherein the structure of the pitch control system can be referred to above. Figure 1 The description of the pitch system shown is provided below. The structure of the pitch system fault detection device can be found in the description of the pitch system fault detection device in the above embodiments, and will not be repeated here.

[0175] Figure 8 A schematic diagram of the hardware structure of the fault detection device for the pitch system provided in an embodiment of this application is shown.

[0176] The fault detection device for the pitch system may include a processor 801 and a memory 802 storing computer program instructions.

[0177] Specifically, the processor 801 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0178] Memory 802 may include mass storage for data or instructions. For example, and not limitingly, memory 802 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 802 may include removable or non-removable (or fixed) media. Where appropriate, memory 802 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 802 is non-volatile solid-state memory.

[0179] Memory 802 may include read-only memory (ROM), random access memory (RAM), disk storage media device, optical storage media device, flash memory device, electrical, optical, or other physical / tangible memory storage device. Therefore, typically, memory 802 includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of this disclosure.

[0180] The processor 801 reads and executes computer program instructions stored in the memory 802 to implement any of the fault detection methods for the pitch system in the above embodiments.

[0181] In one example, the fault detection device for the pitch system may further include a communication interface 803 and a bus 810. For example, Figure 8 As shown, the processor 801, memory 802, and communication interface 803 are connected through bus 810 and complete communication with each other.

[0182] The communication interface 803 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0183] Bus 810 includes hardware, software, or both, that couples components of an online data traffic metering device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 710 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0184] Furthermore, in conjunction with the fault detection method for the pitch system in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the fault detection methods for the pitch system in the above embodiments.

[0185] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0186] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0187] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0188] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0189] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A fault detection method for a pitch system, characterized in that, The pitch system includes a toothed belt, a proximity switch, and a stop for triggering the proximity switch; the method includes: The blade angle and reference angle are obtained when the target proximity switch is triggered; the blade angle is the angle measured by the main encoder located on the pitch motor when the target proximity switch is triggered. Compare the blade angle with the reference angle, and update the positive and / or negative count data corresponding to the target proximity switch based on the comparison result; Based on the updated positive and negative count data, the type of fault that occurred in the pitch system is determined; The step of obtaining the reference angle when the target proximity switch is triggered includes: If it is determined that the target proximity switch is being triggered for the first time, a preset angle is obtained as the reference angle when the target proximity switch is triggered. If it is determined that the target proximity switch is not being triggered for the first time, the blade angle when the target proximity switch was previously triggered is obtained as the reference angle when the target proximity switch is triggered.

2. The method according to claim 1, characterized in that, The step of updating the positive and / or negative count data corresponding to the target proximity switch based on the comparison result includes: If the comparison result shows that the blade angle is greater than the reference angle, the positive count data corresponding to the target proximity switch is incremented by one; If the comparison result shows that the blade angle is less than the reference angle, the negative count data corresponding to the target proximity switch is incremented by one.

3. The method according to claim 2, characterized in that, The step of determining the fault type of the pitch system based on the updated positive and negative count data includes: If both the updated positive count data and the negative count data are greater than or equal to the first threshold, it is determined that the target proximity switch has a loosening fault and / or the stop has a loosening fault.

4. The method according to claim 2, characterized in that, The step of determining the fault type of the pitch system based on the updated positive and negative count data includes: If both the updated positive count data and the negative count data are greater than 0 and less than the first threshold, it is determined that the toothed belt has a loosening fault.

5. The method according to claim 4, characterized in that, Before determining that the toothed belt has become loose, the method further includes: The first time taken from when both the positive count data and the negative count data are 0 to when both the positive count data and the negative count data are less than the first threshold is determined; Compare the first time with the time threshold; The determination that the toothed belt has become loose includes: If the first time is greater than or equal to the time threshold, it is determined that the toothed belt has a loosening fault.

6. The method according to claim 4, characterized in that, Before determining that the toothed belt has become loose, the method further includes: Determine the target difference between the blade angle and the reference angle when the target proximity switch is triggered; Compare the target difference with the angle threshold. The determination that the toothed belt has become loose includes: If the target difference is found to be greater than or equal to the angle threshold, it is determined that the toothed belt has a loosening fault.

7. The method according to claim 2, characterized in that, The step of determining the fault type of the pitch system based on the updated positive and negative count data includes: If the updated negative count data is 0 and the positive count data is greater than or equal to the second threshold, it is determined that the toothed belt has broken.

8. The method according to claim 1, characterized in that, Before obtaining the blade angle when the target proximity switch is triggered and the reference angle of the target proximity switch, the method further includes: When the pitch system is started, the reference angle, positive count data, and negative count data corresponding to the target proximity switch are initialized.

9. A fault detection device for a pitch system, characterized in that, The pitch system includes a toothed belt, a proximity switch, and a stop for triggering the proximity switch; the fault detection device includes: The acquisition unit is used to acquire the blade angle and reference angle when the target proximity switch is triggered; the blade angle is the angle measured by the main encoder located on the pitch motor when the target proximity switch is triggered. A comparison unit is used to compare the size of the blade angle and the reference angle; An update unit is used to update the positive count data and / or negative count data corresponding to the target proximity switch based on the comparison result between the blade angle and the reference angle. The fault determination unit is used to determine the type of fault that has occurred in the pitch system based on the updated positive count data and the negative count data; The acquisition unit is used for: If it is determined that the target proximity switch is being triggered for the first time, a preset angle is obtained as the reference angle when the target proximity switch is triggered. If it is determined that the target proximity switch is not being triggered for the first time, the blade angle when the target proximity switch was previously triggered is obtained as the reference angle when the target proximity switch is triggered.

10. A wind turbine generator set, characterized in that, include: A pitch system and a fault detection device for the pitch system as described in claim 9; The pitch system includes a proximity switch, a stop for triggering the proximity switch, and a toothed belt.

11. A fault detection device for a pitch system, characterized in that, The device includes: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, it implements the fault detection method for the pitch system as described in any one of claims 1-8.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the fault detection method for the pitch system as described in any one of claims 1-8.

13. A computer program product, characterized in that, When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device performs the fault detection method for the pitch system as described in any one of claims 1-8.

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