Method, apparatus and medium for handling encoder failure in a variable pitch system

Abstract

The application discloses a variable pitch system encoder fault processing method, device, equipment and medium, and the method comprises the following steps: determining the rotation number of a target variable pitch motor corresponding to a target blade in a variable pitch system within a preset time length; determining the angle mutation frequency of the target blade within the preset time length based on the output signal of a target encoder corresponding to the target blade in the variable pitch system within the preset time length; comparing the rotation number with the angle mutation frequency; and in response to the rotation number being consistent with the angle mutation frequency, determining that the target encoder has a multi-turn signal abnormality. According to the embodiment, the multi-turn signal abnormality of the variable pitch system encoder is diagnosed and analyzed according to the operation characteristics of the variable pitch system, effectively solving the problem that the traditional diagnosis method has an uncertain single-turn signal change amplitude, an uncertain single-turn signal change frequency, an uncertain pause time length and the like, and improving the detection accuracy.

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 medium for handling encoder faults in a pitch system. Background Technology

[0002] A wind turbine is a device that converts wind energy into electrical energy. Wind energy is converted into electrical energy by the impeller driving the main shaft, speed increaser, and generator set. This electrical energy is then transmitted to the power grid through grid connection control. The pitch system plays a crucial role in the maximum power tracking (MPTS) of the wind turbine and ensuring safe shutdown. Currently, the control method for the pitch system of a wind turbine is as follows: The main control system detects the actual rotational speed of the wind turbine and sets a target rotational speed based on the turbine model characteristics. By performing PID calculations on the deviation between the target and actual rotational speeds, the target blade angle is output. Upon receiving the target angle value from the main control system, the pitch system uses the absolute value signal from the encoder to collect changes in the blade angle, forming a closed-loop PID negative feedback control with the pitch motor, thereby controlling the speed and direction of the pitch motor. The pitch motor meshes with the internal gear ring of the impeller via a drive gear, thus allowing direct control of the blade angle.

[0003] The encoders in pitch systems are typically photoelectric encoders. Because the transmission ratio from the motor side to the blade side in a pitch system is relatively large, multi-turn encoders are generally used. The counting principle of a multi-turn encoder is as follows: after a single-turn revolution, the multi-turn count is incremented by 1; when the multi-turn count reaches full scale, the encoder value becomes 0, and counting restarts. In a pitch system, the blade angle value is determined based on the multi-turn signal and the single-turn signal from the multi-turn encoder.

[0004] During the operation of a wind turbine, various abnormalities may cause the encoder corresponding to the blade to experience multiple-turn signal anomalies. After the encoder experiences multiple-turn signal anomalies, as the value of each single turn changes, the value of multiple turns no longer accumulates. This results in the blade angle value determined based on the encoder output signal always being a small angle value. This will cause the wind turbine to detect different positions of the three blades, leading to a fault and shutdown of the wind turbine. Moreover, because the blade angle value is always a small angle value, the wind turbine will trigger the limit switch during the pitch retraction process. In addition, it may also cause the drive to restart multiple times. To avoid the risk of blade jamming, the protection method of wind turbines is generally to detect that one blade angle is less than a certain angle. After the other two blades have finished retracting, the pitch controller will restart the drive to try to bring the blades back to a safe position. Furthermore, due to the encoder failure, the incremental signal and the calculated pitch motor speed value will no longer be usable as a reference.

[0005] To mitigate the adverse effects of encoder multi-turn signal anomalies, encoder troubleshooting is necessary. Existing methods for troubleshooting or detecting encoder faults typically involve statistical analysis of encoder usage data to determine if multi-turn signal anomalies have occurred. However, factors such as different encoder types, propeller speeds, rotor models, propeller ratios, and data acquisition cycles all influence data waveforms, making parameter setting difficult and resulting in low detection accuracy through statistical analysis. Summary of the Invention

[0006] This application provides a method, apparatus, device, medium, and program for handling encoder faults in a pitch system, which can accurately identify multi-turn signal anomalies in the encoder of the pitch system.

[0007] In a first aspect, embodiments of this application provide a method for handling encoder faults in a pitch system, including:

[0008] Determine the number of rotations of the target pitch motor corresponding to the target blade in the pitch system within a preset time period;

[0009] Based on the output signal of the target encoder corresponding to the target blade in the pitch system within a preset time period, determine the number of angle change events of the target blade within the preset time period;

[0010] Compare the number of rotations with the number of angle abrupt changes;

[0011] The signal anomaly in the target encoder is determined to be present in multiple rotations, as the number of rotations and angle abrupt changes are consistent.

[0012] Secondly, embodiments of this application provide a pitch system encoder fault handling device, comprising:

[0013] The first determining module is used to determine the number of rotations of the target pitch motor corresponding to the target blade in the pitch system within a preset time period;

[0014] The second determining module is used to determine the number of angle changes of the target blade within a preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within a preset time period.

[0015] The comparison module is used to compare the number of rotations with the number of angle abrupt changes;

[0016] The anomaly detection module is used to determine, in response to the consistency between the number of rotation revolutions and the number of angle abrupt changes, that there is a multi-revolution signal anomaly in the target encoder corresponding to the target blade in the pitch system.

[0017] Thirdly, embodiments of this application provide an electronic device, which includes: a processor and a memory storing computer program instructions;

[0018] When the processor executes computer program instructions, it implements a pitch system encoder fault handling method as described in the first aspect.

[0019] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the pitch system encoder fault handling method of the first aspect.

[0020] Fifthly, 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 pitch system encoder fault handling method as described by the first party.

[0021] This application discloses a method, apparatus, device, and medium for handling encoder faults in a pitch system. The method includes: determining the number of rotations of a target pitch motor corresponding to a target blade in the pitch system within a preset time period; determining the number of angle abrupt changes of the target blade within the preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within the preset time period; comparing the number of rotations with the number of angle abrupt changes; and determining that the target encoder has a multi-turn signal anomaly if the number of rotations and the number of angle abrupt changes are consistent. According to this embodiment, the multi-turn signal anomaly of the pitch system encoder is diagnosed and analyzed based on the operating characteristics of the pitch system, effectively solving the problem of inaccurate diagnostic results caused by uncertain amplitude and frequency of single-turn signal changes and uncertain duration of pauses in traditional diagnostic methods, thus improving detection accuracy. Attached Figure Description

[0022] 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.

[0023] Figure 1 This is a schematic diagram of the blade angle variation curves of three blades in a wind turbine generator set provided in an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the blade angle value change curve of the faulty shaft blade provided in the embodiments of this application;

[0025] Figure 3 This is a flowchart illustrating the encoder fault handling method for a pitch system provided in an embodiment of this application.

[0026] Figure 4 This is a schematic diagram of the blade angle value change curve of the target blade provided in the embodiments of this application;

[0027] Figure 5 This is a schematic diagram of the leaf angle value change curve when the target leaf undergoes a sudden angle change, as provided in the embodiments of this application;

[0028] Figure 6 This is a flowchart illustrating a method for handling encoder faults in a pitch system under an application scenario provided in this application embodiment;

[0029] Figure 7 This is a schematic diagram of the structure of the encoder fault handling device for the pitch system provided in the embodiments of this application;

[0030] Figure 8 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] To facilitate understanding, the terminology used in the embodiments of this application will be explained first:

[0034] Feathering refers to the control process of turning the blades of a wind turbine generator to a position close to parallel to the wind direction (also known as a safe position, specifically around 89 degrees) after a malfunction occurs.

[0035] In wind turbine generators, the pitch angle is the angle between any blade and the plane containing the three blades, taken as a reference plane. Specifically, the pitch angle on a wind turbine refers to the angle between the airfoil chord at the blade tip and the plane of rotation.

[0036] An encoder, typically referring to a photoelectric encoder, is a device that uses the principle of grating diffraction to convert mechanical geometric displacement into a digital signal, and then encodes and converts the digital signal into a signal format that can be used for communication, transmission, and storage. Since the 1950s, it has been used in machine tools and computing instruments. Due to its simple structure, high measurement accuracy, and long lifespan, it has been widely used in precision positioning, speed measurement, length measurement, and angle measurement.

[0037] A multi-turn encoder is a device used to measure rotation angles. It can measure rotation angles with high precision and high speed, and output the data to the motion control system, thereby enabling precise positioning and motion control of equipment such as robots and CNC machine tools.

[0038] Multi-turn signals are pulse signals in a multi-turn encoder that correspond to multi-turn data.

[0039] A single-turn signal is a pulse signal used in a multi-turn encoder to correspond with single-turn data.

[0040] Before describing the technical solutions provided in the embodiments of this application, in order to facilitate understanding of the embodiments of this application, this application first specifically explains the problems existing in the prior art:

[0041] In pitch control systems, multi-turn encoders can experience signal anomalies due to various issues during operation. When this occurs, the multi-turn value stops changing as the single-turn value detected by the encoder increases. This leads to inaccurate blade angle values ​​calculated from the encoder's output signal. (See also...) Figure 1 This is a schematic diagram showing the change curves of the blade angle values ​​of three blades in a wind turbine generator. The horizontal axis represents the time value, and the vertical axis represents the blade angle value. Taking the wind turbine generator retracting its propellers at time 0 as an example... Figure 1As shown, when time is less than 0, the blade angle value change curves of the three blades basically overlap, and the encoders of all three blades are operating normally. However, after time is greater than 0, the blade angle value change curves of two blades still overlap, and the blade angle values ​​continue to increase. Therefore, these two blades can retract the propeller normally. The change curve of the other blade (hereinafter referred to as the faulty shaft blade for ease of distinction) shows only slight fluctuations in the blade angle value, and the overall trend is a horizontal straight line. The reason for this phenomenon is that the multi-turn signal of the encoder corresponding to the faulty shaft blade is abnormal, causing the actual position of the faulty shaft blade to change, i.e., it is in a retracted propeller state. However, the pitch controller in the pitch system no longer changes the blade angle value of the faulty shaft blade collected by the encoder. Further, see... Figure 2 ,for Figure 1 The schematic diagram of the blade angle value change curve of the faulty shaft blade after time 0 is a curve showing the change of blade angle after the encoder corresponding to the faulty shaft blade shows multiple abnormal signals. Its change characteristics are that the blade angle value fluctuates or jumps continuously, but the total value always remains in a fixed range or range. Figure 2 The waveform shown, although seemingly regular, is actually... Figure 2 It is evident that the amplitude, frequency, and number and duration of short pauses differ during each transition. Based on the operating principle of the pitch system, the main reasons for this are as follows:

[0042] The first reason is that the different acquisition cycles of the PLC result in different data points being acquired. That is, although the pulse count of the encoder per revolution is 4196 or 8912, the value acquired by each acquisition point is random because the PLC has a scanning cycle (such as 10ms or 20ms). It is not possible to acquire the maximum or minimum value every time.

[0043] The second reason is that because the encoder rotates synchronously with the pitch motor, different pitch adjustment or retraction speeds result in different encoder speeds and thus different frequencies. This is illustrated in the frequency variation shown in the diagram. For different models and different retraction speeds, other frequencies may also appear. Therefore, frequency detection is difficult to accurately identify multi-turn signal anomalies because parameter settings are very sensitive.

[0044] The third reason: such as Figure 1 As shown, the values ​​paused briefly between 12 and 20, which can significantly affect the data statistics.

[0045] The fourth reason: different encoder types, different models, and different total transmission ratios can also lead to differences in amplitude or frequency.

[0046] The fifth reason is that methods for detecting frequency or amplitude changes can easily be confused with normal pitch control changes, leading to false detections. In some cases, angle fluctuations may also be caused by fluctuations in a given speed.

[0047] Therefore, it is difficult to accurately detect or identify the cause of encoder failure by relying solely on data statistics, that is, it is impossible to accurately identify whether multi-turn signal abnormalities have occurred.

[0048] Based on the above analysis and reasons, in order to accurately identify multi-turn signal anomalies in the encoder, this application provides a novel method, apparatus, electronic device, and storage medium for handling encoder faults in a pitch system.

[0049] The following describes the encoder fault handling method for the pitch system provided in the embodiments of this application.

[0050] See Figure 3 This is a flowchart illustrating a method for handling encoder faults in a pitch system, provided in an embodiment of this application. The execution entity of this method can be the pitch controller in the pitch system. Figure 3 As shown, the method may include the following steps S31-S34.

[0051] S31. Determine the number of rotations of the target pitch motor corresponding to the target blade in the pitch system within a preset time period.

[0052] In some embodiments of this application, the target blade refers to the blade in the wind turbine generator that requires encoder fault handling.

[0053] The pitch control system of a wind turbine mainly includes a pitch controller and three servo control systems. These three servo control systems control the blade angle value of each blade in the wind turbine. Each servo control system includes a pitch motor and a corresponding encoder. In this embodiment, after determining the target blade, the pitch motor corresponding to the target blade in the pitch control system is designated as the target pitch motor, and the encoder corresponding to the target blade is designated as the target encoder.

[0054] In this embodiment, the number of rotations of the target pitch motor refers to the number of rotations of the output shaft of the target pitch motor. In practical applications, the rotation of the output shaft of the target pitch motor drives the target blade to rotate, thereby adjusting the angle value of the target blade. Therefore, there is a corresponding relationship between the number of rotations of the target pitch motor and the angle change value of the target blade. Based on this, the number of rotations of the target pitch motor within the preset time period can be determined according to the angle change value of the target blade within the preset time period.

[0055] The preset duration can be set according to actual conditions, such as 1 second, 2 seconds, 5 seconds, etc. However, in order to improve the reliability of the wind turbine generator, the preset duration should not be too long, and in order to eliminate the case of a single jump in the target encoder, the preset duration should not be too short.

[0056] S32. Based on the output signal of the target encoder corresponding to the target blade in the pitch system within a preset time period, determine the number of angle changes of the target blade within the preset time period.

[0057] Among them, the number of angle mutations of the target leaf within the preset time period refers to the number of times the target leaf undergoes angle mutations within the preset time period.

[0058] In some embodiments of this application, multiple sampling times can be set within a preset time period. For each sampling time period, the angle value of the target blade at that sampling time is calculated based on the signal output by the target encoder. For any two adjacent sampling times, if the difference between the two angle values ​​of the target blade calculated at the two adjacent sampling times is greater than a preset difference threshold, it is determined that a sudden change has occurred in the target blade. The number of angle sudden changes determined within the preset time period is accumulated to obtain the number of angle sudden changes of the target blade within the preset time period. The difference threshold can be set according to the actual situation, for example, it can be 0.15 degrees.

[0059] Typically, if the target blade experiences a sudden angle change within a preset time period, it can be determined that the target blade is faulty, and this fault may be caused by an abnormal multi-turn signal from the target encoder. Therefore, to further determine whether the fault is indeed caused by an abnormal multi-turn signal from the target encoder, step S33 is executed. If the target blade does not experience a sudden angle change within the preset time period, it can be assumed that the target encoder does not have an abnormal multi-turn signal, because an abnormal multi-turn signal usually causes a sudden angle change in the target blade. In this case, subsequent steps S33-S34 do not need to be executed.

[0060] S33. Compare the number of rotations with the number of angle abrupt changes.

[0061] After obtaining the number of rotations and the number of angle changes, the number of rotations and the number of angle changes are compared to determine the relationship between them, and then the relationship is used to determine whether the number of rotations and the number of angle changes are consistent.

[0062] In some embodiments of this application, when comparing the number of rotations with the number of angle changes, it can be determined whether the number of rotations is less than the number of angle changes. If the number of rotations is less than the number of angle changes, it is determined that the number of rotations and the number of angle changes are inconsistent. If the number of rotations is not less than the number of angle changes, that is, the number of rotations is greater than or equal to the number of angle changes, the difference between the number of rotations and the number of angle changes can be further calculated. If the difference is less than 1, it is determined that the number of rotations and the number of angle changes are consistent. If the difference is greater than or equal to 1, it is determined that the number of rotations and the number of angle changes are inconsistent. The reason for determining that the number of rotations and the number of angle abrupt changes are the same when the difference is less than 1 is that there may be cases where the number of rotations is a floating-point number, meaning it is not an integer. Since the value of less than one rotation can be calculated, while the number of angle abrupt changes can only be detected when an abrupt change occurs, meaning the number of angle abrupt changes is an integer, even a fault caused by abnormal multi-rotation signals can result in the number of rotations and the number of angle abrupt changes being unequal. Therefore, to ensure the accuracy of the detection, the number of rotations and the number of angle abrupt changes are also determined to be the same when the number of rotations is greater than the number of angle abrupt changes and the difference between the two is less than 1.

[0063] S34. In response to the consistency between the number of rotations and the number of angle abrupt changes, it is determined that there is a multi-turn signal anomaly in the target encoder corresponding to the target blade in the pitch system.

[0064] In some embodiments of this application, the target encoder is a multi-turn photoelectric encoder, which mainly consists of a grating disk and a photoelectric detection device. The grating disk is coaxially arranged with the target pitch motor. The rotation of the target pitch motor drives the rotation of the grating disk, and the photoelectric detection device outputs several pulse signals. The rotational speed of the target pitch motor can be calculated based on the number of pulses per second of this pulse signal. The counting principle of the multi-turn photoelectric encoder is as follows: after the grating disk reaches its maximum value in a single turn, the multi-turn count is incremented by 1. For example, for a 12×12 multi-turn photoelectric encoder, this means there are 2 to the power of 12 pulses per turn, totaling 4096 pulses, i.e., the maximum value for a single turn is 4096 turns. When a single turn reaches 4096 turns, the multi-turn count is incremented by 1, and the single-turn count is reset to 0. In a pitch system, the multi-turn count of the multi-turn encoder is usually consistent with the number of rotations of the pitch motor. Based on this, after a multi-turn signal fault occurs in the target encoder, the multi-turn count value no longer increases, but the single-turn signal value continues to change according to the pattern of returning to 0 once after reaching its maximum value. This causes the angle value of the target blade, determined based on the target encoder, to abruptly change each time it returns to 0. Therefore, if no other abnormalities occur in the target blade within a preset time period, the number of angle abrupt changes within that time period is equivalent to the multi-turn count value of the target encoder under normal conditions, which is consistent with the number of rotations of the target pitch motor within the preset time period. Therefore, when it is determined that there is an angle abrupt change in the target blade within the preset time period, by comparing the number of angle abrupt changes with the number of rotations of the target pitch motor, it can be determined whether the fault in the target blade is caused by an abnormality in the multi-turn signal of the target encoder. If the number of angle abrupt changes is consistent with the number of rotations, it indicates that the fault is caused by an abnormality in the multi-turn signal, thus confirming that the target encoder has an abnormal multi-turn signal; otherwise, it is determined that there is another abnormality.

[0065] The pitch system encoder fault handling method provided in this application determines the number of rotations of the target pitch motor corresponding to the target blade within a preset time period. Based on the output signal of the target encoder corresponding to the target blade within the preset time period, it determines the number of angle abrupt changes of the target blade within the preset time period. The number of rotations is compared with the number of angle abrupt changes. If the number of rotations and the number of angle abrupt changes are consistent, it is determined that the target encoder has a multi-turn signal anomaly. According to this embodiment, the multi-turn signal anomaly of the pitch system encoder is diagnosed and analyzed based on the operating characteristics of the pitch system. This effectively solves the problem of inaccurate diagnostic results caused by uncertain amplitude and frequency of single-turn signal changes, and uncertain duration of pauses in traditional diagnostic methods, thus improving detection accuracy.

[0066] Furthermore, the pitch system encoder fault handling method provided in this application embodiment can promptly diagnose the true cause of the fault, reduce fault troubleshooting time, and indirectly reduce power generation loss due to maintenance.

[0067] Furthermore, traditional statistical analysis-based fault detection methods, due to varying pulse counts among different encoder types, correspond to different blade angle ranges, making it difficult to adapt parameter thresholds to all encoder types. Moreover, different propeller retrieval speeds also significantly impact the data waveform. In contrast, the pitch system encoder fault handling method provided in this application is not limited by encoder type and is applicable to any type of encoder, thus offering greater applicability.

[0068] Furthermore, the encoder fault handling method for the pitch system provided in this application embodiment is not limited by the PLC scanning cycle or data acquisition cycle, and therefore has wider versatility and applicability.

[0069] In some possible real-time methods of this application, determining the number of rotations of the target pitch motor corresponding to the target blade in the pitch system within a preset time period may include:

[0070] Determine the rotational speed of the target blade;

[0071] The first angle value that the target blade rotates through within a preset time period is determined based on the rotational speed;

[0072] Based on the first angle value and the target total transmission ratio, determine the second angle value through which the pitch motor rotates within a preset time period. The target total transmission ratio is the total transmission ratio between the target blade and the target pitch motor.

[0073] The number of rotations of the target pitch motor within a preset time period is determined based on the ratio of the second angle value to one full rotation angle.

[0074] Here, a full circle angle refers to the angle formed by a ray rotating around its endpoint once, that is, 360 degrees.

[0075] In some embodiments of this application, if the ratio of the second angle value to the full circle is an integer, the ratio can be determined as the number of rotations of the target pitch motor within a preset time period. If the ratio of the second angle value to the full circle is a floating-point number, that is, a value with a decimal, the value obtained by rounding down the ratio can be determined as the number of rotations of the target pitch motor within a preset time period. For example, if the ratio is 12.8, the integer value 12 is taken as the number of rotations of the target pitch motor within a preset time period. The purpose of this is to ensure that if the failure of the target blade is caused by the abnormality of the multi-turn signal of the target encoder, the number of rotations of the target pitch motor within a preset time period can be equal to the number of angle changes of the target blade.

[0076] In some embodiments of this application, if the ratio of the second angle value to the full circle angle is a floating-point number, the ratio can be directly determined as the number of rotations of the target pitch motor within a preset time period. However, in S33, if the number of rotations is greater than the number of angle abrupt changes and the difference between the two is less than 1, the number of rotations is also determined to be consistent with the number of angle abrupt changes.

[0077] In some embodiments of this application, the number of rotations of the target pitch motor within a preset time period can be calculated using the following formula:

[0078]

[0079] Where b represents the number of revolutions of the target pitch motor within the preset time period, v represents the rotational speed of the target blade, T represents the preset time period, n represents the total transmission ratio between the target blade and the target pitch motor, and 360° represents one revolution. This indicates rounding down to the nearest integer.

[0080] In some embodiments of this application, taking a target blade rotation speed of 2 degrees / second, a target total transmission ratio of 2200, and a preset duration of 1 second as an example, the target pitch motor rotates 2*2200 = 4400 degrees within 1 second, corresponding to 4400 / 360 = 12.2 revolutions, rounded down to 12 revolutions. See also Figure 4 This is a schematic diagram of the change curve of the target leaf's angle value. Taking the sampling of the target leaf's angle value between 1 second and 2 seconds as an example to determine the number of angle abrupt changes within 1 second, such as... Figure 4 As shown, the angle value changed abruptly 12 times between 1 second and 2 seconds. That is, the number of rotations of the target pitch motor within the preset time is the same as the number of angle changes of the target blade within the preset time. Therefore, it can be determined that the target encoder has a multi-turn signal abnormality.

[0081] Using the above method, the number of rotations of the target pitch motor within a preset time period can be quickly calculated.

[0082] In some possible embodiments of this application, the rotational speed of the target blade can be determined in at least one of the following ways:

[0083] The first method is to obtain the blade angle value of the target blade, determine the actual propeller speed of the target blade based on the blade angle value, and use the actual propeller speed as the rotational speed of the target blade.

[0084] The blade angle values ​​of the target blade can be collected multiple times within a certain period of time. The blade angle change curve is determined based on the collected blade angle values, and then the actual blade retraction speed of the target blade is determined based on the blade angle change curve.

[0085] The second method is to obtain the given speed of all blades in the target wind turbine generator set, and take the average value of the given speed of all blades as the rotational speed of the target blade. The target wind turbine generator set is the wind turbine generator set to which the target blade belongs.

[0086] The control method for the pitch system of a wind turbine generator includes the pitch system receiving a speed command (i.e., a given speed) from the main controller of the wind turbine generator and performing pitch adjustment operations to achieve the pitch control function. Here, the value of the speed command issued by the main controller is calculated based on the actual position and the target position of the blades. This application embodiment does not impose any restrictions on this, therefore its detailed description is omitted.

[0087] The reason for choosing the average of the given speeds of the three blades as the rotational speed of the target blade is that when a certain shaft experiences a multi-turn signal anomaly, the main controller will adjust the given speed because the collected angle value is always at a small value.

[0088] The third method is to obtain the feathering speed output by the pitch controller in the pitch system and use the feathering speed as the rotational speed of the target blade.

[0089] The feathering speed is a constant value.

[0090] In practical applications, the rotational speed of the target blades can be determined by selecting one of the three methods mentioned above, based on the operating status of the target wind turbine generator.

[0091] For example, when the target wind turbine is in pitch control mode, the first or second method can be used to determine the target blade speed. When the target wind turbine is in a fault state, a third method can be used to determine the target blade speed.

[0092] Regarding the third approach, since the pitch system will generate a constant feathering speed after triggering a fault in the angle of the three blades, the feathering speed can be used as the rotational speed of the target blade after the fault is triggered. This ensures that the pitch system encoder fault handling in this embodiment is based on a fixed value and will not be affected by changes in the given value.

[0093] In some possible implementations of this application, determining the number of angle changes of the target blade within a preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within a preset time period may include:

[0094] Within a preset duration, the blade angle value of the target blade is sampled once every sampling period based on the output signal of the target encoder;

[0095] For each sampling, if the difference between the leaf angle value obtained in this sampling and the leaf angle value obtained in the previous sampling is greater than the difference threshold, it is determined that the target leaf has experienced a sudden angle change.

[0096] The total number of angular mutations that occur within a preset time period is determined as the number of angular mutations of the target leaf within the preset time period.

[0097] The length of the sampling period can be set according to the actual situation, such as 0.5 seconds, 1 second, etc.

[0098] In some embodiments of this application, before determining the number of angle abrupt changes of the target blade within a preset time period, the user can clear the calculated abrupt change count value c in the pitch control system and set a sampling start time, a preset time period, and a sampling period in the pitch controller according to the actual situation. Thus, when determining the number of angle abrupt changes of the target blade within the preset time period, the pitch controller can calculate the blade angle value of the target blade based on the output signal of the target encoder every sampling period starting from the sampling start time. For each calculated blade angle value, the difference between the calculated blade angle value and the previously calculated blade angle value is calculated. This difference is compared with a difference threshold. If the difference is greater than the difference threshold, the calculated abrupt change count value c is incremented by 1 until the total sampling time reaches the preset time period. The obtained calculated abrupt change count value c is then determined as the number of angle abrupt changes of the target blade within the preset time period. The sampling period can be the PLC scanning period set in the pitch control system.

[0099] In some embodiments of this application, see Figure 5 This is a schematic diagram of the leaf angle change curve when the target leaf undergoes a sudden angle change, such as... Figure 5 As shown, when the blade angle value undergoes a sudden change in the cycle, the time interval between time T1 and time T2 is 3.33 - 3.42 = 0.02 seconds, or 20 ms, which is exactly the PLC's scan cycle. This proves the feasibility and correctness of the method used to determine the number of sudden changes in the target blade angle in the embodiments of this application.

[0100] Using the above method, users only need to set a sampling start time, sampling period, and preset duration to automatically determine the number of angle abrupt changes of the target blade within the preset duration. The operation is simple and efficient. It is not limited by the intermediate angle change process, the magnitude of angle value change, or the given speed.

[0101] In some possible implementations of this application, in response to the consistency between the number of rotation revolutions and the number of angle abrupt changes, determining that there is a multi-turn signal anomaly in the target encoder corresponding to the target blade in the pitch system may further include:

[0102] In response to the consistency between the number of rotations and the number of angle abrupt changes, the amplitude of the angle change of the target blade within a preset time period is determined;

[0103] Compare the angle change amplitude with the preset angle change threshold;

[0104] In response to the angle change amplitude being less than the angle change threshold, it is determined that there is a multi-turn signal anomaly in the target encoder corresponding to the target blade in the pitch system.

[0105] The angle change threshold can be set to a relatively large value, such as 2 degrees or 5 degrees, as long as it is greater than the angle change of the target encoder's single-turn signal. This setting is because if the angle change amplitude is too large, it may be a fault caused by other abnormalities.

[0106] The above methods can further ensure the accuracy of the detection results for multi-turn signal anomalies.

[0107] In some possible implementations of this application, before determining the number of angle changes of the target blade within a preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within a preset time period, the following steps may be performed first:

[0108] Determine whether the capacitance, voltage, and temperature rise of the target pitch motor are all within their respective preset normal ranges;

[0109] Based on the output signal of the target encoder corresponding to the target blade in the pitch system within a preset time period, the number of angle changes of the target blade within the preset time period is determined, including:

[0110] In response to the fact that the capacitance, voltage and temperature rise of the target pitch motor are all within their respective preset normal ranges, the number of angle abrupt changes of the target blade within a preset time period is determined.

[0111] The normal ranges for the target pitch motor's capacitance, voltage, and temperature rise can be set according to actual conditions, such as based on the capacitance, voltage, and temperature rise of the pitch system during normal operation.

[0112] Typically, an abnormal multi-turn signal from the target encoder will not cause abnormalities in the capacitance, voltage, and temperature rise of the target pitch motor, i.e., exceeding the corresponding normal range. However, blade jamming, abnormal incremental signals, and other reasons may cause abnormalities in the capacitance, voltage, and temperature rise of the target pitch motor. Therefore, if the capacitance, voltage, and / or temperature rise of the target pitch motor are abnormal, it can be largely ruled out that the pitch system fault is caused by an abnormal multi-turn signal. In this case, to reduce the computational load, steps S32 and subsequent steps can be skipped.

[0113] The above methods can reduce the amount of computation.

[0114] In some possible implementations of this application, after determining that there is a multi-turn signal anomaly in the target encoder corresponding to the target blade in the pitch system, the following steps can also be performed:

[0115] Output abnormal alarm information, which is used to indicate that there is a multi-turn signal abnormality in the target encoder.

[0116] By outputting alarm information, maintenance personnel can promptly detect anomalies and carry out repairs, thereby effectively reducing the greater adverse effects caused by multiple signal anomalies.

[0117] In some possible implementations of this application, the pitch system can continue to operate after the alarm information is output. Based on this, before outputting the alarm information, it can be further determined whether there is a pitch jamming fault in the pitch system, such as a drive fault. If it is determined that there is no pitch jamming fault, then the alarm information is output.

[0118] When the target encoder exhibits multiple signal anomalies, the position signal of the target blade detected by the driver in the pitch system will be incorrect. This can lead to abnormal operation of the target pitch motor, increased motor current, and even internal driver failure, resulting in a shutdown. Following a driver failure in the pitch system, a jamming phenomenon may occur. In this case, the target pitch motor can no longer drive the target blade to a safe position, posing a significant safety hazard to the wind turbine generator. Therefore, when a jamming fault occurs in the pitch system, instead of issuing an alarm, a jamming fault warning can be output, or the system can be shut down directly to improve the safety of the wind turbine generator.

[0119] In some embodiments of this application, it can be determined whether there is still a propeller jamming fault in the pitch system by detecting the fault word of the pitch system. For example, if the fault word is 0, it is determined that there is no propeller jamming fault, and an alarm message is output.

[0120] In some possible implementations of this application, if only the target blade in the target wind turbine experiences multi-turn signal anomalies while other blades operate normally, it may lead to inconsistent angle values ​​among the three blades, triggering an "angle inconsistency" fault. This fault can cause significant deviations in the wind energy forces acting on the three blades, resulting in uneven rotor force. This will greatly impact the load on the target wind turbine and reduce its service life. Therefore, to improve the safety of the target wind turbine, after confirming the presence of multi-turn signal anomalies in the target encoder corresponding to the target blade in the pitch system, the following steps can also be performed:

[0121] The first moment when the target wind turbine unit is determined to have a blade angle inconsistency fault is the wind turbine unit to which the target blade belongs;

[0122] Obtain the first blade angle value of the target blade at the first moment;

[0123] Determine the cumulative number of angle abrupt changes of the target leaf from the first time point to the second time point, where the number of angle abrupt changes at the second time point is greater than that at the first time point;

[0124] The product of the cumulative number of angle changes and one revolution is determined as the third angle value that the target pitch motor rotates from the first moment to the second moment;

[0125] The ratio of the third angle value to the target total transmission ratio is determined as the fourth angle value through which the target blade rotates from the first moment to the second moment. The target total transmission ratio is the total transmission ratio between the target blade and the target pitch motor.

[0126] The sum of the first and fourth blade angle values ​​is determined as the predicted blade angle value of the target blade at the second moment.

[0127] In some embodiments of this application, the angle inconsistency fault of the target wind turbine can be detected based on the angle difference of the three blades in the target wind turbine. For example, when the angle difference of the three blades in the target wind turbine is greater than a preset angle, it can be determined that the target wind turbine has triggered an angle inconsistency fault. The preset angle can be set in advance according to the actual situation, for example, it can be 2.5 degrees.

[0128] When a fault of inconsistent trigger angle is identified in the target wind turbine generator set, the angle value of the target blade at the first moment of the fault is recorded as the first blade angle value. The number of times the target blade angle changes suddenly, d, is accumulated from the first moment until the second moment is reached. The second moment can be obtained by adding the fault tolerance time to the first moment. The fault tolerance time can be set according to the actual situation, but it should not be too long. For example, the value range of the fault tolerance time can be 30 seconds to 2 minutes.

[0129] Based on the cumulative number of angle abrupt changes d, the angle s that the target pitch motor rotates from the first moment to the second moment can be calculated using the following formula:

[0130] s = d * 360° / n

[0131] Where n represents the total transmission ratio between the target blade and the target pitch motor.

[0132] For example, if the cumulative number of angle abrupt changes of the target blade from the first moment to the second moment is d = 200, then the target pitch motor has rotated 200 revolutions. If the target total transmission ratio is 2200, then the angle value of the target blade from the first moment to the second moment is 200*360 / 2200 = 32.72 degrees. If the angle value of the target blade when the angle inconsistency fault occurs is 9 degrees, then the actual angle value of the target blade at the second moment is also the predicted blade angle value of 9 + 32.72 = 41.72 degrees.

[0133] By using the above method, after the target encoder experiences a multi-turn signal anomaly, the pitch system can continue to operate based on the predicted blade angle value of the target blade within the fault tolerance period, thus achieving short-term fault-tolerant operation of the pitch system during normal pitch adjustment.

[0134] In some possible implementations of this application, after determining the sum of the first blade angle value and the fourth blade angle value as the predicted blade angle value of the target blade at the second moment, the following steps can also be performed:

[0135] Determine whether the target blade has completed its paddle retraction based on the predicted blade angle value;

[0136] In response to the target blade completing its retraction, determine whether other blades have completed their retraction;

[0137] In response to the completion of the retraction of all other blades, the driver of the target pitch motor stops outputting.

[0138] In some embodiments of this application, when determining whether a target blade has completed propeller retraction based on a predicted blade angle value, the predicted blade angle value can be compared with a preset propeller retraction stopping angle. If the predicted blade angle value is greater than the propeller retraction stopping angle, it can be determined that the target blade has completed propeller retraction; if the blade angle value is not greater than the propeller retraction stopping angle, it can be determined that the target blade has not completed propeller retraction. The propeller retraction stopping angle can be preset according to actual conditions, usually a value close to 90 degrees, for example, 88 degrees.

[0139] In some embodiments of this application, taking a pitch stop angle of 88 degrees as an example, after the pitch controller obtains the predicted blade angle of the target blade at the second moment, it determines whether the predicted blade angle is greater than 88 degrees. If the predicted blade angle is greater than 88 degrees, it is determined that the target blade has completed pitch stop; if the predicted blade angle is not greater than 88 degrees, it is determined that the target blade has not completed pitch stop.

[0140] In some other embodiments of this application, to improve control accuracy, when determining whether the target blade has completed propeller retraction based on the predicted blade angle value, the predicted blade angle value can first be compared with a preset propeller retraction stopping angle. If the blade angle value is not greater than the propeller retraction stopping angle, it can be determined that the target blade has not completed propeller retraction. If the predicted blade angle value is greater than the propeller retraction stopping angle, it is further determined whether the proximity switch corresponding to the target blade has been triggered. If the proximity switch is triggered, it can be determined that the target blade has completed propeller retraction; if the proximity switch is not triggered, it can be determined that the target blade has not completed propeller retraction. Compared to determining whether the target blade has completed propeller retraction based on the predicted blade angle value, the determination result based on the triggering state of the proximity switch is more accurate, thus ensuring control accuracy.

[0141] For each of the other blades, when determining whether the blade has completed propeller retraction, the blade angle value of the blade can be obtained. Similar to the method of determining whether the target blade has completed propeller retraction, for each blade, the blade angle value of the blade can be compared with the propeller retraction stopping angle to determine whether the blade has completed propeller retraction. Alternatively, the blade angle value of the blade and the corresponding proximity switch of the blade can be used to jointly determine whether the blade has completed propeller retraction. For the specific determination process, please refer to the determination process corresponding to the target blade mentioned above. To avoid repetition, it will not be repeated here.

[0142] When all three blades of the target wind turbine have completed their retraction, the pitch controller can control the driver of the target pitch motor to output a given speed of 0, causing the driver to stop running and the target pitch motor to stop rotating. This prevents the limit switch from being triggered and avoids damage to the toothed belt or mechanical parts caused by exceeding the limit switch.

[0143] In some possible implementations of this application, the aforementioned driver for controlling the target pitch motor based on predicted blade angle values ​​is mainly applicable to scenarios where a single shaft fault occurs in the target wind turbine generator set, i.e., scenarios where only the target encoder experiences multi-turn signal anomalies. Therefore, before determining whether other blades have completed pitch retraction, it is possible to first determine whether the encoders corresponding to other blades have multi-turn signal anomalies. If none of the encoders corresponding to other blades have multi-turn signal anomalies, then it can be determined whether the other blades have completed pitch retraction. The method for detecting whether the encoders corresponding to other blades have multi-turn signal anomalies is the same as the method for detecting whether the target encoder has multi-turn signal anomalies; to avoid repetition, it will not be described again here.

[0144] The above methods can further ensure the accuracy of control.

[0145] The following example illustrates the method for handling encoder faults in a pitch system by applying the pitch system encoder fault handling method provided in this application to a wind turbine generator set for fault handling of the target blade.

[0146] See Figure 6 The troubleshooting method for encoder faults in a pitch control system may include the following steps:

[0147] S61. The angle mutation count value c is cleared to zero, and the pitch controller collects the angle values ​​of the three blades and sets the speed value.

[0148] S62. Determine whether the capacitance, voltage, and motor temperature rise of the target pitch motor corresponding to the target blade are normal. If yes, proceed to S63; otherwise, end.

[0149] This step is to determine whether there is any jamming or abnormal incremental signal in the pitch system, ensuring the accuracy of the detection.

[0150] S63. Determine if there is a sudden change in angle in the target leaf. If yes, proceed to S64; otherwise, proceed to S65.

[0151] This step is to determine the change in angle value. If the difference in the angle value of the target blade collected by the two adjacent collection points in the previous and subsequent cycles is greater than the difference threshold, then it is considered that a sudden change in angle has occurred.

[0152] S64. Increment the angle mutation count value c by 1.

[0153] If an angle change greater than 0.15 degrees is detected, the count value is incremented by 1; the total number of jumps within a fixed time period is detected.

[0154] S65. Determine whether the preset duration T has been reached. If yes, execute S66; otherwise, return to execute S63.

[0155] The time T can be freely set, such as to 1 second, 2 seconds, 5 seconds, etc. However, in order to implement the subsequent feathering safety protection control method, the T setting should not be too long. In order to eliminate the case of single jump, the T setting should not be too short either.

[0156] S66. Determine if the angle mutation count value c is greater than 0. If yes, proceed to S67; otherwise, end the process.

[0157] S67. Based on the given speed value and total transmission ratio n, calculate the number of revolutions b of the target pitch motor corresponding to the target blade within time T.

[0158] The specific calculation formula for this step is as follows:

[0159]

[0160] Where b represents the number of revolutions of the target pitch motor within a preset time period, v represents the given speed, T represents the preset time period, n represents the total transmission ratio between the target blade and the target pitch motor, and 360° represents one revolution. This indicates rounding down to the nearest integer.

[0161] S68. Determine whether the condition c = b and the angle change within T seconds is less than the threshold is met. If yes, proceed to S69; otherwise, end.

[0162] This step mainly includes two checks:

[0163] Check if the values ​​of c and b are the same.

[0164] The step of detecting whether the change in the detection angle exceeds a certain value, such as 2 degrees or 5 degrees, and whether the change in the detection angle is less than a threshold, is to further ensure the accuracy of the detection. The threshold can be set to a relatively large value, such as 2 degrees or 5 degrees, as long as it is greater than the change in angle of a single revolution of the encoder signal.

[0165] S69. Output alarm message indicating that the target encoder has multiple turns of abnormal signal.

[0166] If the detected value c equals the value b within time T, and there are no other abnormalities in the pitch system, then an alarm message indicating an abnormal multi-turn signal from the encoder will be output.

[0167] S610. Based on the alarm information, the angle value of the target blade when the pitch system triggers an angle inconsistency fault, and the cumulative number of angle mutations of the target blade within the fault tolerance period, determine the predicted blade angle value of the target blade.

[0168] This step refers to the process where, if a multi-turn signal anomaly is detected in the target encoder, the pitch controller determines the predicted blade angle value of the target blade based on the angle value of the target blade when the "angle inconsistency" fault is triggered, and the cumulative number of angle mutations of the target blade within the fault tolerance period.

[0169] For example, when the difference in the angle values ​​of the three blades in a wind turbine unit is greater than 2.5 degrees, an angle inconsistency fault is determined to be triggered, and the angle value of the target blade is recorded at this time.

[0170] Let d be the cumulative number of angle mutations within the tolerance period. The angle value rotated by the target pitch motor within the tolerance period can be calculated using the following formula:

[0171] s = d * 360° / n

[0172] Where n represents the total transmission ratio between the target blade and the target pitch motor.

[0173] When the angle value rotated by the target pitch motor is inconsistent with the trigger angle, the angle value of the target blade is recorded and added together to obtain the predicted blade angle of the target blade.

[0174] This calculation method can also be used for fault-tolerant operation during normal pitch adjustment for a short period of time, but the fault tolerance time should not be too long. Furthermore, the starting condition uses a sudden angle change as the criterion; the initial angle is the angle before the angle change, not the angle at the time of the fault.

[0175] S611. Determine whether the condition that the predicted blade angle value is greater than 88 and the proximity switch corresponding to the target blade is triggered is met. If yes, execute S612; otherwise, end.

[0176] S612. Determine whether the remaining blades, excluding the target blade, meet the following conditions: the blade angle value of each blade is greater than 88 degrees, the proximity switch corresponding to each blade is triggered, and the encoder corresponding to each blade does not have an alarm message indicating multiple turns of abnormal signal. If yes, execute S613; otherwise, end.

[0177] S613. Stop the output of the driver corresponding to the target pitch motor and stop the pitching of the target blade.

[0178] This step is the feathering safety protection involved in the embodiments of this application. When it is detected that the actual position of the blade has reached the safe position, the pitch controller controls the output of the drive, that is, sets the given speed to 0, so that the drive stops running and the pitch motor stops rotating, preventing the limit switch from being triggered and preventing the toothed belt from being torn off or the mechanical parts from being damaged due to exceeding the limit switch.

[0179] Based on the pitch system encoder fault handling method provided in the above embodiments, this application also provides a specific implementation of the pitch system encoder fault handling device. Please refer to the following embodiments.

[0180] See Figure 7 The pitch system encoder fault handling device provided in this application embodiment includes the following modules:

[0181] The first determining module 701 is used to determine the number of rotations of the target pitch motor corresponding to the target blade in the pitch system within a preset time period.

[0182] The second determining module 702 is used to determine the number of angle changes of the target blade within a preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within a preset time period.

[0183] Comparison module 703 is used to compare the number of rotations with the number of angle abrupt changes;

[0184] The anomaly determination module 704 is used to determine, in response to the fact that the number of rotations and the number of angle abrupt changes are consistent, that there is a multi-turn signal anomaly in the target encoder corresponding to the target blade in the pitch system.

[0185] This application discloses a fault handling device for a pitch system encoder. It determines the number of rotations of the target pitch motor corresponding to the target blade within a preset time period. Based on the output signal of the target encoder corresponding to the target blade within the preset time period, it determines the number of angle abrupt changes of the target blade within the preset time period. The number of rotations is compared with the number of angle abrupt changes. If the number of rotations and the number of angle abrupt changes are consistent, it is determined that the target encoder has a multi-turn signal anomaly. According to this embodiment, the multi-turn signal anomaly of the pitch system encoder is diagnosed and analyzed based on the operating characteristics of the pitch system. This effectively solves the problems of inaccurate diagnostic results caused by uncertain amplitude and frequency of single-turn signal changes, and uncertain duration of pauses in traditional diagnostic methods, thus improving detection accuracy.

[0186] In some possible implementations of this application, the first determining module 701 includes:

[0187] The rotational speed determination submodule is used to determine the rotational speed of the target blade;

[0188] The first angle determination submodule is used to determine the first angle value that the target blade has rotated through within a preset time period based on the rotation speed.

[0189] The second angle determination submodule is used to determine the second angle value that the pitch motor rotates within a preset time period based on the first angle value and the target total transmission ratio. The target total transmission ratio is the total transmission ratio between the target blade and the target pitch motor.

[0190] The revolutions determination submodule is used to determine the number of revolutions of the target pitch motor within a preset time period based on the ratio of the second angle value to one revolution.

[0191] In some possible implementations of this application, the rotational speed determination submodule is specifically used for:

[0192] Obtain the blade angle value of the target blade, determine the actual propeller retraction speed of the target blade based on the blade angle value, and use the actual propeller retraction speed as the rotational speed of the target blade; or,

[0193] Obtain the given speed of all blades in the target wind turbine generator set, and take the average of the given speeds of all blades as the rotational speed of the target blade. The target wind turbine generator set is the wind turbine generator set to which the target blade belongs; or,

[0194] Obtain the feathering speed output by the pitch controller in the pitch system, and use the feathering speed as the rotational speed of the target blade.

[0195] In some possible implementations of this application, the second determining module 702 is specifically used for:

[0196] Within a preset duration, the blade angle value of the target blade is sampled once every sampling period based on the output signal of the target encoder;

[0197] For each sampling, if the difference between the leaf angle value obtained in this sampling and the leaf angle value obtained in the previous sampling is greater than the difference threshold, it is determined that the target leaf has experienced a sudden angle change.

[0198] The total number of angular mutations that occur within a preset time period is determined as the number of angular mutations of the target leaf within the preset time period.

[0199] In some possible implementations of this application, the exception determination module 704 is specifically used for:

[0200] In response to the consistency between the number of rotations and the number of angle abrupt changes, the amplitude of the angle change of the target blade within a preset time period is determined;

[0201] Compare the angle change amplitude with the preset angle change threshold;

[0202] In response to the angle change amplitude being less than the angle change threshold, it is determined that there is a multi-turn signal anomaly in the target encoder corresponding to the target blade in the pitch system.

[0203] In some possible implementations of this application, the apparatus may further include:

[0204] The anomaly module is used to determine whether the capacitance, voltage and temperature rise of the target pitch motor are within their respective preset normal ranges before determining the number of angle abrupt changes of the target blade within a preset time period.

[0205] The second determining module 702 is specifically used for:

[0206] In response to the fact that the capacitance, voltage and temperature rise of the target pitch motor are all within their respective preset normal ranges, the number of angle changes of the target blade within the preset time period is determined based on the output signal of the target encoder corresponding to the target blade in the pitch system within the preset time period.

[0207] In some possible implementations of this application, the apparatus further includes:

[0208] The blade angle prediction module is used to determine the first moment when the target wind turbine generator set experiences a blade angle inconsistency fault after determining that there are multiple turns of abnormal signals in the target encoder corresponding to the target blade in the pitch system. The target wind turbine generator set is the wind turbine generator set to which the target blade belongs.

[0209] Obtain the first blade angle value of the target blade at the first moment;

[0210] Determine the cumulative number of angle abrupt changes of the target leaf from the first time point to the second time point, where the number of angle abrupt changes at the second time point is greater than that at the first time point;

[0211] The product of the cumulative number of angle changes and one revolution is determined as the third angle value that the target pitch motor rotates from the first moment to the second moment;

[0212] The ratio of the third angle value to the target total transmission ratio is determined as the fourth angle value through which the target blade rotates from the first moment to the second moment. The target total transmission ratio is the total transmission ratio between the target blade and the target pitch motor.

[0213] The sum of the first and fourth blade angle values ​​is determined as the predicted blade angle value of the target blade at the second moment.

[0214] In some possible implementations of this application, the apparatus further includes: a control module, used for:

[0215] After determining the sum of the first blade angle value and the fourth blade angle value as the predicted blade angle value of the target blade at the second moment, the predicted blade angle value is used to determine whether the target blade has completed propeller retraction and whether it is greater than the preset propeller retraction stopping angle.

[0216] In response to the target blade completing its retraction, determine whether other blades have completed their retraction;

[0217] In response to the completion of the retraction of all other blades, the driver of the target pitch motor stops outputting.

[0218] The pitch system encoder fault handling device provided in this application embodiment can achieve... Figures 3 to 6 The various processes implemented in the method implementation examples will not be described again here to avoid repetition.

[0219] Figure 8 A schematic diagram of the hardware structure of the electronic device provided in an embodiment of this application is shown.

[0220] Electronic devices may include a processor 801 and a memory 802 storing computer program instructions.

[0221] 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.

[0222] Memory 802 may include a large-capacity memory for data or instructions. For example, and not limitingly, memory 802 may include a hard disk drive (HDD), a floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. 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. Memory 802 may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Thus, 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 performs the operations described in any of the pitch system encoder fault handling methods in the above embodiments.

[0223] The processor 801 reads and executes computer program instructions stored in the memory 802 to implement any of the pitch system encoder fault handling methods in the above embodiments.

[0224] In one example, the electronic device may also 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.

[0225] The communication interface 803 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0226] 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 810 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.

[0227] Furthermore, in conjunction with the pitch system encoder fault handling method 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 pitch system encoder fault handling methods in the above embodiments.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] 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 method for handling encoder faults in a pitch control system, characterized in that, include: Determine the number of rotations of the target pitch motor corresponding to the target blade in the pitch system within a preset time period; Based on the output signal of the target encoder corresponding to the target blade in the pitch system within the preset time period, the number of angle abrupt changes of the target blade within the preset time period is determined; Compare the number of rotations with the number of angle abrupt changes; In response to the fact that the number of rotations is consistent with the number of angle abrupt changes, it is determined that the target encoder has a multi-turn signal anomaly.

2. The method according to claim 1, characterized in that, Determining the number of rotations of the target pitch motor corresponding to the target blade in the pitch system within a preset time period includes: Determine the rotational speed of the target blade; Based on the rotational speed, determine the first angle value through which the target blade rotates within the preset time period; Based on the first angle value and the target total transmission ratio, the second angle value through which the pitch motor rotates within the preset time period is determined, and the target total transmission ratio is the total transmission ratio between the target blade and the target pitch motor; The number of rotations of the target pitch motor within a preset time period is determined based on the ratio of the second angle value to one full rotation.

3. The method according to claim 2, characterized in that, The rotational speed of the target blade is determined using at least one of the following methods: Obtain the blade angle value of the target blade, determine the actual blade retraction speed of the target blade based on the blade angle value, and use the actual blade retraction speed as the rotational speed of the target blade; The given speed of all blades in the target wind turbine generator set is obtained, and the average value of the given speed of all blades is taken as the rotational speed of the target blade. The target wind turbine generator set is the wind turbine generator set to which the target blade belongs. Obtain the feathering speed output by the pitch controller in the pitch system, and use the feathering speed as the rotational speed of the target blade.

4. The method according to claim 1, characterized in that, The step of determining the number of angle abrupt changes of the target blade within the preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within the preset time period includes: Within the preset duration, the blade angle value of the target blade is sampled once every sampling period based on the output signal of the target encoder; For each sampling, if the difference between the leaf angle value obtained in this sampling and the leaf angle value obtained in the previous sampling is greater than the difference threshold, it is determined that the target leaf has undergone a sudden angle change. The total number of angle mutations that occur within the preset time period is determined as the number of angle mutations of the target blade within the preset time period.

5. The method according to claim 1, characterized in that, The response that the number of rotations matches the number of angle abrupt changes determines that the target encoder corresponding to the target blade in the pitch system has a multi-turn signal anomaly, including: In response to the fact that the number of rotations is consistent with the number of angle abrupt changes, the amplitude of the angle change of the target blade within the preset time period is determined; The angle change amplitude is compared with a preset angle change threshold. In response to the angle change amplitude being less than the angle change threshold, it is determined that there is a multi-turn signal anomaly in the target encoder corresponding to the target blade in the pitch system.

6. The method according to any one of claims 1-5, characterized in that, Before determining the number of angle abrupt changes of the target blade within the preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within the preset time period, the method further includes: Determine whether the capacitance, voltage, and temperature rise of the target pitch motor are all within their respective preset normal ranges; The step of determining the number of angle abrupt changes of the target blade within the preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within the preset time period includes: In response to the fact that the capacitance, voltage and temperature rise of the target pitch motor are all within their respective preset normal ranges, the number of angle abrupt changes of the target blade within the preset time period is determined based on the output signal of the target encoder corresponding to the target blade in the pitch system within the preset time period.

7. The method according to any one of claims 1-5, characterized in that, After determining that the target encoder corresponding to the target blade in the pitch system has a multi-turn signal anomaly, the method further includes: The first moment when the target wind turbine generator set is determined to have a blade angle inconsistency fault, the target wind turbine generator set is the wind turbine generator set to which the target blade belongs; Obtain the first blade angle value of the target blade at the first moment; The cumulative number of angle abrupt changes of the target blade from the first time point to the second time point is determined, wherein the second time point is greater than the first time point; The product of the cumulative number of angle changes and one revolution is determined as the third angle value that the target pitch motor rotates from the first moment to the second moment; The ratio of the third angle value to the target total transmission ratio is determined as the fourth angle value through which the target blade rotates from the first moment to the second moment, and the target total transmission ratio is the total transmission ratio between the target blade and the target pitch motor; The sum of the first blade angle value and the fourth angle value is determined as the predicted blade angle value of the target blade at the second moment.

8. The method according to claim 7, characterized in that, After determining the sum of the first blade angle value and the fourth angle value as the predicted blade angle value of the target blade at the second moment, the method further includes: Determine whether the target blade has completed its paddle retraction based on the predicted blade angle value; In response to the target blade completing propeller retraction, determine whether other blades have completed propeller retraction; In response to the completion of the retraction of all other blades, the driver controlling the target pitch motor stops outputting.

9. A fault handling device for a pitch system encoder, characterized in that, include: The first determining module is used to determine the number of rotations of the target pitch motor corresponding to the target blade in the pitch system within a preset time period; The second determining module is used to determine the number of angle abrupt changes of the target blade within the preset time period based on the output signal of the target encoder corresponding to the target blade in the pitch system within the preset time period; The comparison module is used to compare the number of rotations with the number of angle abrupt changes; An anomaly determination module is used to determine, in response to the fact that the number of rotations is consistent with the number of angle abrupt changes, that there is a multi-turn signal anomaly in the target encoder corresponding to the target blade in the pitch system.

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

11. 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 pitch system encoder fault handling method as described in any one of claims 1-8.

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