Yaw self-checking system and self-checking method for wind generating set

Abstract

The invention discloses a yaw self-checking system and self-checking method for a wind generating set, and relates to the technical field of wind driven generators. The yaw self-checking system comprises a sensing system, a data collector and a data analysis module; the sensing system comprises displacement sensors and current sensors, the current sensors are installed on power supply lines of yaw driving motors, and each driving motor is provided with at least one current sensor; the displacement sensor is installed on a front rack of the wind generating set, the tooth top of a yaw bearing gear ring serves as an induction reflection face, and the displacement sensor is an eddy current sensor. The data acquisition unit is used for acquiring real-time current signals of each displacement sensor and each current sensor; the data analysis module is used for analyzing the real-time current signals of the displacement sensor and the current sensors collected by the data collector, obtaining a fault analysis result and sending the fault analysis result to the master control system. Through active driving detection in a shutdown state and in combination with synchronous analysis of current and displacement, accurate identification of yaw driving motor system faults and gear ring jumping can be realized, and early diagnosis and early warning of the faults of the yaw system are realized.

Description

Technical Field

[0001] This invention relates to the field of wind turbine technology, and more specifically to the field of a wind turbine yaw self-testing system and self-testing method. Background Technology

[0002] The yaw system of a wind turbine generator set is a core component that ensures the wind turbine is always aligned with the wind, thereby improving power generation efficiency. Its core function is to drive the wind turbine nacelle and the wind turbine to rotate around the tower axis, ensuring that the wind turbine is always aligned with the wind direction and maximizing wind energy capture. The yaw system mainly consists of a yaw drive motor, a reduction gearbox, a yaw ring gear, a braking device, and a control system. Among these, the power output stability of the yaw drive motor and the meshing accuracy of the yaw ring gear directly determine the operational reliability of the yaw system. During long-term service of wind turbine generator sets, the yaw system is prone to failure due to complex operating conditions such as gusts and wind shear. For example, wear on the drive motor bearings can cause jamming, and poor contact in the drive circuit can lead to abnormal current. Initially, these faults manifest as fluctuations in the drive motor's operating current. If not detected in time, they can cause the drive motor to overload and burn out, and even trigger a chain reaction of failures such as gearbox gear jamming and brake failure. Furthermore, the yaw gear ring is subjected to alternating forces from the nacelle's weight and wind load over a long period, making it susceptible to tooth surface wear and gear ring deformation. This can result in excessive radial runout (radial deviation of the outer circle or tip circle of the gear ring) or end face runout. Excessive runout causes inconsistent gear meshing clearance during yaw operation, leading to load impacts on the drive motor, accelerating wear on the drive motor and gears, and simultaneously reducing yaw positioning accuracy, increasing rotor deviation from the wind, and decreasing power generation efficiency.

[0003] Currently, fault detection in the yaw system of wind turbine generators mainly relies on two methods: one is to detect anomalies through vibration sensors of the CMS system; the other is offline manual inspection, where the wind turbine generator is periodically shut down, and maintenance personnel climb to the top of the nacelle to conduct inspections.

[0004] Existing offline manual inspection methods suffer from inefficiency and low accuracy. They require maintenance personnel to periodically shut down the unit and climb into the nacelle for inspection, which has several drawbacks: First, they are inefficient, taking 2-3 hours to inspect a single unit and disrupting power generation. Second, they are inaccurate, relying on personnel experience; misalignment of the dial indicator installation can lead to measurement errors exceeding 0.3mm. Third, they have blind spots, failing to accurately identify hidden faults such as internal short circuits in the drive motor windings, making it difficult to meet the requirements for accurate yaw system fault identification. Fourth, they can only detect problems after they occur, unable to provide early warnings. Furthermore, using vibration sensors from the CMS cannot directly reflect the yaw system status, resulting in a very high false alarm rate. Summary of the Invention

[0005] The purpose of this invention is to solve the aforementioned technical problems by providing a yaw self-checking system and method for wind turbine generator sets. This system enables wind turbine generator sets to perform self-checks under no-wind or low-wind-speed conditions where they are not generating electricity, and achieves early prediction and warning of faults.

[0006] To achieve the above objectives, the present invention specifically adopts the following technical solution: One aspect of the present invention provides a yaw self-test system for a wind turbine generator set, including a sensing system, a data acquisition unit, and a data analysis module; The sensing system includes a displacement sensor and a current sensor. The current sensor is installed on the power supply line of the yaw drive motor, and at least one current sensor is installed on each drive motor. The displacement sensor is installed on the front frame of the wind turbine generator set, and the tooth tip of the yaw bearing gear ring is used as the sensing and reflecting surface. The displacement sensor is an eddy current sensor. The data acquisition unit is used to acquire the real-time current signals of each displacement sensor and each current sensor; The data analysis module is used to analyze the real-time current signals of the displacement sensor and various current sensors collected by the data acquisition unit, obtain fault analysis results, and send them to the main control system.

[0007] A second aspect of the present invention provides a self-testing method for a wind turbine generator yaw self-testing system, comprising the following steps: S1. Self-inspection preparation stage; S2, Current data analysis and fault diagnosis stage; S21. Divide the N drive motors of the yaw system into K groups according to the principle of symmetrical distribution. The number of drive motors in each group is determined according to the driving capacity of the drive motors to ensure that a single group of drive motors can safely drive the unit to yaw. At the same time, the drive motors should be analyzed according to the principle of symmetry. When the total number cannot be divided by the number of groups, the remaining drive motors are matched with the tested drive motors. For example, 8 drive motors are divided into 4 groups, and each group of drive motors is arranged symmetrically at 180° along the circumference of the nacelle (such as the first drive motor and the fifth drive motor in one group, and the second drive motor and the sixth drive motor in one group), to ensure that the load characteristics of each group are theoretically consistent.

[0008] S22, Yaw Drive Control: The data analysis module sends a low-speed drive command to the yaw drive motor through the main control system, driving the nacelle to yaw in turn, while other drive motors are turned off, and the yaw rotates 360 degrees. S23. Data Acquisition: The current sensor collects the operating current signal of each yaw drive motor in real time and records the current change curve over time in groups; S3, Current Data Analysis and Fault Diagnosis Stage: S4. Actual tooth backlash calculation (combining tooth profile and reference tooth backlash) S5. Self-inspection result feedback and processing stage.

[0009] In one implementation, the self-test preparation stage in step S1 includes the following specific details: S11. Triggering condition judgment: The system receives the main control system instruction and confirms that the wind turbine generator is in a shutdown state, the wind turbine speed is 0, the nacelle is unlocked, the yaw brake device is in a released state, and the external conditions such as the power grid and weather meet the self-test safety requirements. S12. Equipment initialization: The data analysis module sends a start command to the data acquisition unit, performs self-tests on the displacement sensor and current sensor, confirms that the sensor power supply is normal and the signal output is stable, and completes zero-point calibration.

[0010] In one implementation, in step S23, the current sensor collects the operating current signal of each yaw drive motor in real time and records the current change curve over time in groups; the specific steps are as follows: S231. During the driving process of each group of drive motors, the current sensor synchronously collects the real-time current of two drive motors (sampling frequency 1kHz), and after processing by the data acquisition unit, it is stored as an "angle-current" dataset: The dataset for the i-th group of drive motors is: ; In the formula, i is the group number. ; Angle number (1° interval); , The two drive motors in the i-th group are respectively The current value at the angle; S232. Data preprocessing: Filter each set of current data (using a 5th-order Butterworth low-pass filter with a cutoff frequency of 50Hz) to remove power grid interference and mechanical vibration noise, and obtain a smooth current curve.

[0011] In one implementation, the inter-group current comparison analysis in step S31 is as follows: S311. Calculate the average current value of each group of drive motors: Take the average current of the i-th group within a 360° range to obtain the average operating current of the group. The formula for calculating the average operating current is as follows: ; S312. Calculate the inter-group current consistency index: The formula for calculating the mean current of all groups is as follows: The formula for calculating the standard deviation of current between groups is as follows: The formula for calculating the current deviation of the i-th group is as follows: ; S313, Fault Judgment Threshold: If a certain group (Can be calibrated according to the model), and The system determines that there is an abnormality in the drive motor, such as a short circuit in the winding, a stuck bearing causing a high load, or a loose connection causing a low load.

[0012] In one implementation, step S32 involves analyzing angle changes within a group, specifically determining abnormal correlations in the angles of the drive motors within the same group. The specific steps are as follows: S321. Calculate the current fluctuation value of a single drive motor at different angles: For the first drive motor in the i-th group, calculate the current range within 360°, that is, the difference between the maximum and minimum values, as follows: ; Similarly, calculate the current range of the second drive motor in this group. ; S322. Calculate the variance of the current angle within the group: Take the average of the current values ​​of the two drive motors in the i-th group ( Then calculate the angular variance within 360°, using the following formula: S323, Fault Judgment Threshold: S3231, If or That is, the current fluctuation of a single drive motor exceeds the average value by 1.5 times, or the multiple of the current fluctuation of a single drive motor exceeding the average value can be customized according to the actual situation of the unit; S3232, then it is determined that there is an angle-related abnormality in the group of drive motors, such as excessive tooth ring runout, which leads to sudden load changes and unstable output torque of drive motor.

[0013] In one implementation, step S3231 is replaced by the following: or That is, the square of the angular variance exceeding the mean by 20% corresponds to the standard deviation exceeding the mean by 20%, or the percentage of the angular variance exceeding the mean can be customized according to the actual situation of the unit. In one implementation, the specific method for calculating the actual tooth backlash in step S4 is as follows: S41. Calculation of single tooth tip runout: (The following is a partial calculation of the tooth tip runout) The actual tip circle radius of each tooth tip From measured displacement With fixed installation height The derivation and calculation formula are as follows: Among them, subtract the radius of the tooth tip arc. Since the sensor detects the highest point of the tooth tip arc, it needs to be restored to the radius corresponding to the theoretical center of the tooth tip circle; The runout deviation of the tooth tip (The deviation relative to the theoretical tip circle radius) is: ;in, This indicates that the tooth tip is too high. This indicates that the tooth tip is too low; S42. Calculation of actual tooth clearance for a single tooth: The actual tooth clearance is calculated from the "reference tooth clearance". "and tooth tip runout deviation" "Reverse association:" When the tooth tip is too high At this time, the meshing clearance between the drive gear and the gear ring will decrease, and the actual tooth clearance will... for: ; When the tooth tip is too low At this time, the meshing clearance will increase, and the actual tooth clearance will increase. for: .

[0014] In one implementation, the specific process of the self-test result feedback and processing stage in step S5 is as follows: S51. If a group simultaneously meets the conditions of inter-group anomaly, intra-group angle change anomaly, and backlash fault, it is judged as a "serious fault", triggering the main control system alarm and locking the yaw. S52. If only one of the conditions is met, it is determined to be a "minor fault". Record the fault group number, abnormal current value and associated angle range, and prompt the maintenance personnel to carry out targeted repairs. S53. When all groups are free of abnormalities, the unit self-check is complete.

[0015] The beneficial effects of this invention are as follows: 1. The self-testing system of this invention consists of a sensing system, a data acquisition unit, and a data analysis module. Through active drive detection in a stopped state, combined with synchronous analysis of current and displacement, the system can accurately identify faults in the yaw drive motor system and gear runout, achieving early diagnosis and warning of yaw system faults.

[0016] 2. This invention achieves accurate identification of yaw drive motor system faults and gear runout by actively driving detection in a stopped state, combined with synchronous analysis of current and displacement, without the need for long-term online monitoring, thus balancing detection efficiency and cost control. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of a yaw self-testing system and self-testing method for wind turbine generator sets according to the present invention.

[0019] Figure 2 This is a schematic diagram of the principle of a yaw self-testing system and self-testing method for wind turbine generator sets according to the present invention. Detailed Implementation

[0020] To make the technical problems, technical solutions, and technical effects of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] In the description of the embodiments of the present invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0024] Example 1 like Figure 1 As shown, this embodiment provides a yaw self-test system for wind turbine generator sets, including a sensing system, a data acquisition unit, and a data analysis module; The sensing system includes a displacement sensor and a current sensor. The current sensor is installed on the power supply line of the yaw drive motor, and at least one current sensor is installed on each drive motor. The displacement sensor is installed on the front frame of the wind turbine generator set, and the tooth tip of the yaw bearing gear ring is used as the sensing and reflecting surface. The displacement sensor is an eddy current sensor. The data acquisition unit is used to acquire the real-time current signals of each displacement sensor and each current sensor; The data analysis module is used to analyze the real-time current signals of the displacement sensor and various current sensors collected by the data acquisition unit, obtain fault analysis results, and send them to the main control system.

[0025] Example 2 This embodiment provides a self-testing method for a wind turbine generator yaw self-testing system. Using the aforementioned wind turbine generator yaw self-testing system, the method includes the following steps: S1. Self-inspection preparation stage: S11. Triggering condition judgment: The system receives the main control system instruction and confirms that the wind turbine generator is in a shutdown state, the wind turbine speed is 0, the nacelle is unlocked, the yaw brake device is in a released state, and the external conditions such as the power grid and weather meet the self-test safety requirements. S12. Equipment initialization: The data analysis module sends a start command to the data acquisition unit, performs self-tests on the displacement sensor and current sensor, confirms that the sensor power supply is normal and the signal output is stable, and completes zero-point calibration. S2, Current data analysis and fault diagnosis stage; S21. Divide the N drive motors of the yaw system into K groups according to the principle of symmetrical distribution. The number of drive motors in each group is determined according to the driving capacity of the drive motors to ensure that a single group of drive motors can safely drive the unit to yaw. At the same time, the drive motors should be analyzed according to the principle of symmetry. When the total number cannot be divided by the number of groups, the remaining drive motors are matched with the tested drive motors. For example, 8 drive motors are divided into 4 groups, and each group of drive motors is arranged symmetrically at 180° along the circumference of the nacelle (such as the first drive motor and the fifth drive motor in one group, and the second drive motor and the sixth drive motor in one group), to ensure that the load characteristics of each group are theoretically consistent.

[0026] S22, Yaw Drive Control: The data analysis module sends a low-speed drive command to the yaw drive motor through the main control system, driving the nacelle to yaw in turn, while other drive motors are turned off, and the yaw rotates 360 degrees. S23. Data Acquisition: The current sensor collects the operating current signal of each yaw drive motor in real time and records the current change curve over time in groups; S3, Current Data Analysis and Fault Diagnosis Stage: S231. During the driving process of each group of drive motors, the current sensor synchronously collects the real-time current of two drive motors (sampling frequency 1kHz), and after processing by the data acquisition unit, it is stored as an "angle-current" dataset: The dataset for the i-th group of drive motors is: ; In the formula, i is the group number; Angle number (1° interval); , The two drive motors in the i-th group are respectively The current value at the angle; S232. Data preprocessing: Filter each set of current data (using a 5th-order Butterworth low-pass filter with a cutoff frequency of 50Hz) to remove power grid interference and mechanical vibration noise, and obtain a smooth current curve.

[0027] In one implementation, the inter-group current comparison analysis in step S31 is as follows: S311. Calculate the average current value of each group of drive motors: Take the average current of the i-th group within a 360° range to obtain the average operating current of the group. The formula for calculating the average operating current is as follows: ; S312. Calculate the inter-group current consistency index: The formula for calculating the mean current of all groups is as follows: The formula for calculating the standard deviation of current between groups is as follows: The formula for calculating the current deviation of the i-th group is as follows: ; S313, Fault Judgment Threshold: If a certain group (Can be calibrated according to the model), and The system determines that there is an abnormality in the drive motor, such as a short circuit in the winding, a stuck bearing causing a high load, or a loose connection causing a low load.

[0028] In one implementation, step S32 involves analyzing angle changes within a group, specifically determining abnormal correlations in the angles of the drive motors within the same group. The specific steps are as follows: S321. Calculate the current fluctuation value of a single drive motor at different angles: For the first drive motor in the i-th group, calculate the current range within 360°, that is, the difference between the maximum and minimum values, as follows: ; Similarly, calculate the current range of the second drive motor in this group. ; S322. Calculate the variance of the current angle within the group: Take the average of the current values ​​of the two drive motors in the i-th group ( Then calculate the angular variance within 360°, using the following formula: S323, Fault Judgment Threshold: S3231, If or This means the current fluctuation of a single drive motor exceeds the average value by 1.5 times, or a custom multiple of the current fluctuation exceeding the average value of a single drive motor can be defined based on the actual situation of the unit; or That is, the square of the angular variance exceeding the mean by 20% corresponds to the standard deviation exceeding the mean by 20%, or the percentage of the angular variance exceeding the mean can be customized according to the actual situation of the unit. S3232 indicates that the drive motor group has an angle-related abnormality, such as excessive tooth ring runout, which leads to sudden load changes and unstable output torque of the drive motor.

[0029] S4. Actual tooth backlash calculation (combining tooth profile and reference tooth backlash), the specific process is as follows: S41. Calculation of single tooth tip runout: (The following is a partial calculation of the tooth tip runout) The actual tip circle radius of each tooth tip From measured displacement With fixed installation height The derivation and calculation formula are as follows: Among them, subtract the radius of the tooth tip arc. Since the sensor detects the highest point of the tooth tip arc, it needs to be restored to the radius corresponding to the theoretical center of the tooth tip circle; The runout deviation of the tooth tip (The deviation relative to the theoretical tip circle radius) is: ;in, This indicates that the tooth tip is too high. This indicates that the tooth tip is too low; S42. Calculation of actual tooth clearance for a single tooth: The actual tooth clearance is calculated from the "reference tooth clearance". "and tooth tip runout deviation" "Reverse association:" When the tooth tip is too high At this time, the meshing clearance between the drive gear and the gear ring will decrease, and the actual tooth clearance will... for: ; When the tooth tip is too low At this time, the meshing clearance will increase, and the actual tooth clearance will increase. for: .

[0030] S5. Self-inspection result feedback and processing stage, the specific process is as follows: S51. If a group simultaneously meets the conditions of inter-group anomaly, intra-group angle change anomaly, and backlash fault, it is judged as a "serious fault", triggering the main control system alarm and locking the yaw. S52. If only one of the conditions is met, it is determined to be a "minor fault". Record the fault group number, abnormal current value and associated angle range, and prompt the maintenance personnel to carry out targeted repairs. S53. When all groups are free of abnormalities, the unit self-check is complete.

Claims

1. A yaw self-test system for a wind turbine generator set, characterized in that, Includes a sensing system, a data acquisition unit, and a data analysis module; The sensing system includes a displacement sensor and a current sensor. The current sensor is installed on the power supply line of the yaw drive motor, and at least one current sensor is installed on each drive motor. The displacement sensor is installed on the front frame of the wind turbine generator set, and the tooth tip of the yaw bearing gear ring is used as the sensing and reflecting surface. The displacement sensor is an eddy current sensor. The data acquisition device is used to acquire the real-time current signals of each of the displacement sensors and each of the current sensors. The data analysis module is used to analyze the real-time current signals of the displacement sensor and each current sensor collected by the data acquisition device, obtain fault analysis results, and send them to the main control system.

2. A self-testing method for a wind turbine generator yaw self-testing system, characterized in that, The yaw self-test system for a wind turbine generator set according to claim 1 includes the following steps: S1. Self-inspection preparation stage S2, Current Data Analysis and Fault Diagnosis Stage: S21. Divide the N drive motors of the yaw system into K groups according to the principle of symmetrical distribution. The number of drive motors in each group is determined according to the driving capacity of the drive motors to ensure that a single group of drive motors can safely drive the unit to yaw. At the same time, the drive motors should be analyzed according to the principle of symmetry. When the total number cannot be divided by the number of groups, the remaining drive motors are grouped with the tested drive motors. For example, the 8 drive motors are divided into 4 groups, with each group of drive motors arranged symmetrically at 180° around the circumference of the engine compartment to ensure that the load characteristics of each group are theoretically consistent. S22, Yaw Drive Control: The data analysis module sends a low-speed drive command to the yaw drive motor through the main control system, driving the nacelle to yaw in turn, while other drive motors are turned off, and the yaw rotates 360 degrees. S23. Data Acquisition: The current sensor collects the operating current signal of each yaw drive motor in real time and records the current change curve over time in groups; S3, Current Data Analysis and Fault Diagnosis Stage: S4. Calculation of actual tooth clearance; S5. Self-inspection result feedback and processing stage.

3. The self-testing method for a wind turbine generator yaw self-testing system according to claim 2, characterized in that, In step S1, the self-check preparation stage includes the following details: S11. Triggering condition judgment: The system receives the main control system instruction and confirms that the wind turbine generator is in a shutdown state, the wind turbine speed is 0, the nacelle is unlocked, the yaw brake device is in a released state, and the external conditions such as the power grid and weather meet the self-check safety requirements. S12. Equipment initialization: The data analysis module sends a start command to the data acquisition unit, performs self-tests on the displacement sensor and current sensor, confirms that the sensor power supply is normal and the signal output is stable, and completes zero-point calibration.

4. The self-testing method for a wind turbine generator yaw self-testing system according to claim 2, characterized in that, In step S23, the current sensor collects the operating current signal of each yaw drive motor in real time and records the current change curve over time in groups; the specific steps are as follows: S231. During the driving process of each group of drive motors, the current sensor synchronously collects the real-time current of two drive motors, and after processing by the data acquisition unit, it is stored as an "angle-current" dataset: The dataset for the i-th group of drive motors is: ; In the formula, i is the group number. ; Angle number (1° interval); , The two drive motors in the i-th group are respectively The current value at the angle; S232. Data preprocessing: Filter each set of current data to remove power grid interference and mechanical vibration noise, and obtain a smooth current curve.

5. The self-testing method for a wind turbine generator yaw self-testing system according to claim 2, characterized in that, In step S31, the inter-group current comparison analysis is as follows: S311. Calculate the average current value of each group of drive motors: Take the average current of the i-th group within a 360° range to obtain the average operating current of the group. The formula for calculating the average operating current is as follows: ； S312. Calculate the inter-group current consistency index: The formula for calculating the mean current of all groups is as follows: The formula for calculating the standard deviation of current between groups is as follows: The formula for calculating the current deviation of the i-th group is as follows: ； S313, Fault Judgment Threshold: If a certain group ,and The system determines that there is an abnormality in the drive motor, such as a short circuit in the winding, a stuck bearing causing a high load, or a loose connection causing a low load.

6. The self-testing method for a wind turbine generator yaw self-testing system according to claim 5, characterized in that, In step S32, the angle change analysis within the group is performed, which determines whether the angle correlation of the drive motors in the same group is abnormal. The specific steps are as follows: S321. Calculate the current fluctuation value of a single drive motor at different angles: For the first drive motor in the i-th group, calculate the current range within 360°, that is, the difference between the maximum and minimum values, as follows: ; Similarly, calculate the current range of the second drive motor in this group. ; S322. Calculate the variance of the current angle within the group: Take the average of the current values ​​of the two drive motors in the i-th group ( Then calculate the angular variance within 360°, using the following formula: S323, Fault Judgment Threshold: S3231, If or That is, the current fluctuation of a single drive motor exceeds the average value by 1.5 times, or the multiple of the current fluctuation of a single drive motor exceeding the average value can be customized according to the actual situation of the unit; S3232, then it is determined that there is an angle-related abnormality in the group of drive motors, such as excessive tooth ring runout, which leads to sudden load changes and unstable output torque of drive motor.

7. The self-testing method for a wind turbine generator yaw self-testing system according to claim 6, characterized in that, Step S3231 should be replaced with the following: or That is, the square of the angular variance exceeding the mean by 20% corresponds to the standard deviation exceeding the mean by 20%, or the percentage of the angular variance exceeding the mean can be customized according to the actual situation of the unit.

8. A self-testing method for a wind turbine generator yaw self-testing system according to claim 6 or 7, characterized in that, In step S4, the specific method for calculating the actual tooth backlash is as follows: S41. Calculation of single tooth tip runout: No. The actual tip circle radius of each tooth tip From measured displacement With fixed installation height The derivation and calculation formula are as follows: Among them, subtract the radius of the tooth tip arc. Since the sensor detects the highest point of the tooth tip arc, it needs to be restored to the radius corresponding to the theoretical center of the tooth tip circle; The runout deviation of the tooth tip (The deviation relative to the theoretical tip circle radius) is: ;in, This indicates that the tooth tip is too high. This indicates that the tooth tip is too low; S42. Calculation of actual tooth clearance for a single tooth: The actual tooth clearance is calculated from the "reference tooth clearance". "Tooth tip runout deviation" "Reverse association:" When the tooth tip is too high At this time, the meshing clearance between the drive gear and the gear ring will decrease, and the actual tooth clearance will... for: ； When the tooth tip is too low At this time, the meshing clearance will increase, and the actual tooth clearance will increase. for: 。 9. The self-testing method for a wind turbine generator yaw self-testing system according to claim 8, characterized in that, In step S5, the specific process of the self-test result feedback and processing stage is as follows: S51. If a group simultaneously meets the conditions of inter-group anomaly, intra-group angle change anomaly, and backlash fault, it is judged as a "serious fault", triggering the main control system alarm and locking the yaw. S52. If only one of the conditions is met, it is determined to be a "minor fault". Record the fault group number, abnormal current value and associated angle range, and prompt the maintenance personnel to carry out targeted repairs. S53. When all groups are free of abnormalities, the unit self-check is complete.

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