Wind turbine generator anti-seismic performance in-situ evaluation method and system

Abstract

The invention provides a wind turbine generator anti-seismic performance in-situ evaluation method and system, and the method comprises the steps: S1, carrying out the logic screening of a current operation environment and an equipment state, and when a judgment result meets a preset condition, determining an evaluation physical zero point, and entering S2; s2, the stability of the foundation is judged, if the judgment result is qualified, disturbance is applied to carry out a dynamic rebound test, and whether the step S3 is executed or not is determined according to the result; s3, natural wind is used as a loading source, a variable pitch system acts to test the structural rigidity of the tower drum, physical quantity feedback of a displacement sensor is performed for rigidity logic gate judgment, and if the judgment is qualified, S4 is executed; s4, vibration is made through a generator or a variable pitch system, the free attenuation process is monitored after excitation is stopped, and the damping energy dissipation capacity of the system is judged according to the number of vibration cycles; and S5, integrating the results from S2 to S4, and outputting a final anti-seismic performance rating and a corresponding control strategy. In this way, the anti-seismic performance is deconstructed into three physical dimensions including the foundation stability, the tower drum structural rigidity and the system damping energy dissipation capacity, and then step-by-step judgment is conducted.

Description

Technical Field

[0001] This invention relates to the field of seismic performance evaluation of wind turbine generators, and in particular to an in-situ evaluation method and system for the seismic performance of wind turbine generators. Background Technology

[0002] In the current construction of wind farms, most existing methods for assessing the seismic resistance of wind turbines rely on establishing complex mathematical models in the laboratory for simulation calculations, or on using AI algorithms such as neural networks to train historical data.

[0003] However, in actual operation, the physical properties of wind turbines, such as the characteristics of the foundation soil, the tightness of the tower flange connections, and the aeroelasticity of the blades, all change over time. Mathematical models often cannot correct these physical parameters in real time, leading to discrepancies between the assessment results and the actual seismic resistance. Furthermore, existing methods are mostly passive monitoring, unable to actively test the structural stiffness and damping characteristics of the turbine during non-seismic periods, both of which are crucial for seismic performance assessment. Summary of the Invention

[0004] This invention provides an in-situ evaluation method and system for the seismic performance of wind turbine generators, which addresses the shortcomings of existing technologies by deconstructing seismic performance into three physical dimensions: foundation stability, tower structure stiffness, and system damping energy dissipation capacity, and then making a step-by-step assessment.

[0005] This invention provides an in-situ evaluation method for the seismic performance of wind turbine generators, comprising: Step S1: Perform logical screening on the current operating environment and equipment status of the wind turbine. If the judgment result is that the preset conditions are met, establish the physical zero point for evaluation and proceed to step S2. Step S2: Determine the foundation stability using data from the dual-axis tilt sensor. If the determination result is satisfactory, apply a disturbance by controlling the yaw system to conduct a dynamic rebound test. Determine whether to proceed to step S3 based on the test results. Step S3: Using natural wind as a loading source, control the pitch system to test the stiffness of the tower structure. The stiffness logic gate judges the stiffness by the physical quantity feedback of the displacement sensor. If the judgment is qualified, proceed to step S4. Step S4: Actively generate vibration by controlling the generator or pitch system, monitor the free decay process after stopping the excitation, and determine the system's damping energy dissipation capacity based on the number of vibration cycles; Step S5: Based on the judgment results of steps S2 to S4, output the final seismic performance rating and corresponding control strategy of the wind turbine according to the preset decision logic.

[0006] According to the in-situ seismic performance evaluation method for wind turbine generators provided by the present invention, the logical screening step in step S1 specifically includes: Collect real-time wind speed and unit operating status signals; Determine whether the real-time wind speed is within the preset test safety range, and at the same time determine whether the unit is in a fault-free standby or low-load operation state; If all judgment results are "yes", then lock the unit's yaw system and control the pitch system to adjust the blade angle to the full feather position to establish the physical zero point; If any judgment result is "no", an environmental condition non-compliance signal will be output and the evaluation process will be terminated.

[0007] According to the in-situ seismic performance evaluation method for wind turbine generators provided by the present invention, the step of determining foundation stability in step S2 specifically includes: Read the X-axis tilt angle and Y-axis tilt angle values ​​at the bottom of the tower; The absolute values ​​of the X-axis tilt angle and the Y-axis tilt angle are compared with preset static safety thresholds, respectively. If any absolute value is greater than the static safety threshold, the seismic resistance level is determined to be high-risk and subsequent steps are terminated. If both absolute values ​​are less than the static safety threshold, then the dynamic rebound test is performed.

[0008] According to the in-situ seismic performance evaluation method for wind turbine generators provided by the present invention, the dynamic rebound test steps specifically include: The nacelle is rotated by a preset angle to generate a torque disturbance, and then the yaw action is stopped; Monitor whether the tower base tilt angle data recovers to within the deviation range of the initial value within a preset time after the yaw action stops; If the result is "no", it is determined that there is a risk of the foundation becoming loose, and the process is terminated. If the result is "yes", the foundation condition is deemed qualified, and the process can proceed to step S3.

[0009] According to the in-situ seismic performance evaluation method for wind turbine generators provided by the present invention, step S3 specifically includes: The nacelle is aligned with the wind direction, and the blade pitch angle is simultaneously opened to the maximum thrust position. When the wind speed is stable, detect the real-time displacement of the top of the tower. If the real-time displacement is greater than the preset stiffness limit threshold, the tower stiffness is determined to be insufficient, the result is recorded and the subsequent logic of step S3 is skipped. If the real-time displacement does not exceed the stiffness limit threshold, then the unloading and springback determination step is executed.

[0010] According to the in-situ seismic performance evaluation method for wind turbine generators provided by the present invention, the unloading rebound determination step specifically includes: Control the pitch system to perform an emergency feathering maneuver to simulate load removal; Record the actual rebound time required for the tower position to return to physical zero; Compare the actual rebound time with the preset standard rebound time; If the actual rebound time is greater than the sum of the standard rebound time and the allowable error, the structure is judged to have a softening trend. If the actual rebound time is within the allowable range, the tower stiffness is deemed qualified, and the process proceeds to step S4.

[0011] According to the in-situ seismic performance evaluation method for wind turbine generators provided by the present invention, the step of actively generating vibration in step S4 specifically includes: When the unit is shut down, control the generator to apply a short-term reverse torque pulse, or control the pitch system to perform periodic pitch changes at the first natural frequency of the tower. When the monitored vibration amplitude at the top of the tower reaches the preset test safety amplitude, the excitation action is immediately stopped, allowing the wind turbine to enter a free decay vibration state.

[0012] According to the in-situ seismic performance evaluation method for wind turbine generators provided by the present invention, the step of determining the system's damping energy dissipation capacity in step S4 specifically includes: The number of vibration cycles that occur when the vibration amplitude decays from the test safety amplitude to one-tenth of that amplitude is collected; If the number of vibration cycles is greater than the preset low damping warning value, the seismic damping performance is determined to be poor. If the number of vibration cycles is less than the preset overdamping warning value, it is determined to be abnormal damping; If the number of vibration cycles is between the overdamping warning value and the underdamping warning value, the seismic damping performance is determined to be excellent.

[0013] According to the in-situ seismic performance evaluation method for wind turbine generators provided by the present invention, step S5 specifically includes: If step S2 determines that there is a high risk or a risk of foundation loosening, output a strategy to prohibit operation and reinforce the foundation; If step S3 determines that the stiffness is insufficient, output a strategy of stopping the machine for maintenance and checking the bolt torque; If step S4 determines that the seismic damping performance is poor, a strategy of limiting power operation and maintaining the damper is output. If all the above steps are successful but there are weak points in seismic resistance, output a strategy to ensure normal operation and shorten the inspection cycle; If all criteria are met, output "Maintain the current maintenance strategy".

[0014] This invention also provides an in-situ evaluation system for the seismic performance of wind turbine generators, comprising: The environment and status preset screening module performs logical screening on the current operating environment and equipment status of the wind turbine. When the judgment result is that the preset conditions are met, the physical zero point of evaluation is established and the foundation stability logic judgment module is triggered. The foundation stability logic judgment module judges the foundation stability through data from dual-axis tilt sensors. If the judgment result is qualified, it applies a disturbance by controlling the yaw system to conduct a dynamic rebound test. Based on the test result, it decides whether to trigger the tower structure stiffness response analysis module. The tower structure stiffness response analysis module uses natural wind as a loading source to control the pitch system to test the tower structure stiffness. The stiffness logic gate judges the stiffness through the physical quantity feedback of the displacement sensor. If the judgment is qualified, the system damping active disturbance test module is triggered. The system damping active disturbance test module actively generates vibration by controlling the generator or pitch system, monitors the free decay process after the excitation stops, and determines the system damping energy dissipation capacity based on the number of vibration cycles. The seismic performance comprehensive rating output module integrates the judgment results of the above modules and outputs the final seismic performance rating and corresponding control strategy of the wind turbine according to the preset decision logic.

[0015] The in-situ seismic performance assessment method and system for wind turbines provided by this invention, compared with traditional simulation, can reflect the actual bolt tightness, foundation compaction, and material aging of wind turbines based on real physical loading (wind load, torque disturbance) and real physical feedback. This invention does not require complex mathematical modeling and algorithms, but adopts conditional judgment logic based on physical thresholds, making the assessment process traceable and interpretable, facilitating engineers' understanding and adaptation to different turbine models by adjusting physical thresholds. Furthermore, unlike passive post-earthquake assessments, this method can be proactively executed during routine maintenance, identifying potential seismic hazards such as stiffness reduction or damping failure in advance, preventing problems before they occur. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the in-situ evaluation method for the seismic performance of wind turbine generators provided by this invention.

[0018] Figure 2 This is a schematic diagram of the in-situ evaluation system for the seismic performance of wind turbine generators provided by the present invention.

[0019] Figure 3 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0021] The following is combined with Figures 1 to 3 This document describes embodiments of the in-situ assessment method and system for the seismic performance of wind turbine generators according to the present invention. It should be understood that the following descriptions are merely illustrative embodiments of the present invention and do not constitute any specific limitation on the present invention.

[0022] like Figure 1 As shown in the figure, this invention provides an in-situ evaluation method for the seismic performance of wind turbine generators, which may include the following steps: Step S1: Perform logical screening on the current operating environment and equipment status of the wind turbine. If the judgment result is that the preset conditions are met, establish the physical zero point for evaluation and proceed to step S2. Step S2: Determine the foundation stability using data from the dual-axis tilt sensor. If the determination result is satisfactory, apply a disturbance by controlling the yaw system to conduct a dynamic rebound test. Determine whether to proceed to step S3 based on the test results. Step S3: Using natural wind as a loading source, control the pitch system to test the stiffness of the tower structure. The stiffness logic gate judges the stiffness by the physical quantity feedback of the displacement sensor. If the judgment is qualified, proceed to step S4. Step S4: Actively generate vibration by controlling the generator or pitch system, monitor the free decay process after stopping the excitation, and determine the system's damping energy dissipation capacity based on the number of vibration cycles; Step S5: Based on the judgment results of steps S2 to S4, output the final seismic performance rating and corresponding control strategy of the wind turbine according to the preset decision logic.

[0023] The in-situ evaluation method for the seismic performance of wind turbines provided by the present invention can, compared with traditional simulation, reflect the current true bolt fastening degree, foundation compactness, and material aging condition of wind turbines based on real physical loading (wind load, torque disturbance) and real physical feedback. The present invention does not require the use of complex mathematical modeling and algorithms, and adopts a conditional judgment logic based on physical thresholds, making the evaluation process traceable and interpretable, facilitating engineers to understand and adapt to different models by adjusting physical thresholds. In addition, different from the passive evaluation after an earthquake, this method can be actively executed during daily maintenance to detect in advance seismic hidden dangers such as stiffness decline or damping failure, and prevent problems before they occur.

[0024] The above method will be described in detail below in combination with embodiments. It should be understood that the following is only a schematic embodiment of the present invention and does not constitute any limitation to the present invention.

[0025] First, the method of the present invention starts from step S1, that is, logically screening the current operating environment and equipment status of the wind turbine. When the judgment result meets the preset conditions, the evaluation physical zero point is established and step S2 is entered.

[0026] Specifically, step S1 is the starting node of the entire seismic performance evaluation process. Its core purpose is to exclude the interference of uncontrollable environmental factors and abnormal states of the unit itself on subsequent physical tests, and ensure that the tests are carried out under safe and unified benchmarks.

[0027] After the system is started, first, the current real-time wind speed (Vnow) is read through the wind speed sensor connected to the outside of the wind turbine nacelle, and at the same time, the current operating status code is read through the main controller of the unit. In addition, a test safety interval is preset inside the system, and this interval defines the wind speed range (Vmin to Vmax) allowed for seismic physical tests.

[0028] The system compares the collected real-time wind speed Vnow with the preset Vmin and Vmax. If Vnow < Vmin (the wind speed is too small), then when using natural wind as the loading source to push the tower in subsequent step S3, it will not be able to generate enough thrust to cause measurable deformation of the tower barrel, and the data will be distorted. If Vnow > Vmax (the wind speed is too large), then active pitch or yaw at this time may cause the load of the unit to exceed the limit, posing a safety hazard. Therefore, only when Vnow is within this interval, the environmental judgment logic outputs a pass signal (Pass), otherwise it outputs a fail signal (Fail).

[0029] Simultaneously with (or immediately following) the environmental assessment, the system performs a logical check on the unit's operating status. Specifically, the system checks whether the status code corresponds to a fault-free standby or low-load operation mode. If it is a fault shutdown or full-load operation mode, it indicates that the unit may have a mechanical hazard or is in a high-stress grid-connected power generation state. Forcibly introducing active disturbances (such as the sway test in steps S2 and S4) in this situation could easily trigger an accident. Only when the unit is in a safe and controllable state will the status assessment logic output a pass signal.

[0030] If either the environmental assessment or the equipment status assessment results in a failure, the system will immediately output an alarm signal indicating that the environmental conditions are not met or the status is abnormal, and will forcibly terminate the current assessment process without performing any mechanical actions. The system will then return to the monitoring state and wait for the next instruction.

[0031] If both of the above judgment results are "Pass", the system determines that the test conditions are met and then performs the following physical actions to establish the evaluation benchmark: Action A (Yaw Lock): Control the yaw brake to fully close, lock the nacelle position, prevent the nacelle from rotating due to changes in wind direction during subsequent tests, and eliminate interference from vibration tests.

[0032] Action B (full feathering): Control the pitch system to synchronously adjust all blades to the full feathering position (usually 90 degrees, i.e., the leading edge of the blades faces the wind direction and the aerodynamic angle of attack is 0). At this time, the aerodynamic lift on the blades is minimal.

[0033] Establishing the zero point: After actions A and B are completed, the system records the current displacement sensor values ​​and tilt sensor values ​​at the top of the tower, marking them as the physical zero point for this evaluation. All subsequent deformations (such as the displacement in step S3 and the tilt change in S2) are calculated using this zero point as the reference.

[0034] Compared with existing technologies, this invention, by setting dual logic gates for wind speed and status, forcibly eliminates the possibility of active disturbance testing during typhoon days, windless days, or when the unit is operating with defects. This effectively prevents safety accidents such as tower collapse or component damage caused by test actions (e.g., tower shaking). Furthermore, by forcibly executing locked yaw and full feathering actions after logical judgment, a unique physical zero point is established. This eliminates initial aerodynamic load interference caused by random nacelle rotation or inconsistent blade angles, ensuring that the displacement measured in subsequent steps is entirely caused by specific test loads, rather than background noise. This significantly improves the signal-to-noise ratio and accuracy of seismic performance evaluation.

[0035] See also Figure 1After establishing the physical zero point in step S1, the method of the present invention proceeds to step S2. Specifically, the system immediately activates the dual-axis tilt sensor installed at the bottom of the tower (this sensor is rigidly connected to the tower base flange). The system simultaneously reads the real-time tilt angle value Ax of the X-axis (corresponding to the main wind direction or nacelle axis) and the real-time tilt angle value Ay of the Y-axis (perpendicular to the X-axis). Next, the system retrieves the static safety threshold Asafe (this threshold is set based on the unit design specifications and represents the maximum permissible permanent tilt of the tower) pre-stored in the control unit. Then, the following judgment logic is executed: Judgment Logic A (High-Risk Blocking): The system compares |Ax| with Asafe and |Ay| with Asafe. If the absolute value of either value is greater than Asafe, it indicates that the foundation may have experienced irreversible severe settlement or overturning. In this case, the system determines the seismic resistance level to be "high-risk," directly triggering an alarm and forcibly terminating all subsequent assessment steps.

[0036] Judgment Logic B (Initial Screening Passed): Only when |Ax| and |Ay| are both less than Asafe will the system determine that the unit is within the static safety range and automatically trigger the next dynamic rebound test.

[0037] The dynamic rebound test is used to detect whether the foundation exhibits false stability or loosening, meaning it appears normal when stationary but undergoes plastic deformation under stress. Specifically, the system sends a command to the yaw drive motor, controlling the nacelle to rotate rapidly at a preset maximum yaw speed, with the rotation angle set to 90 degrees. This action utilizes the nacelle's large mass inertia to generate a significant torque pulse on the tower base at the moment of start-up and stop. Then, within a preset observation time T1 after the yaw action stops (e.g., within 30 seconds after stopping), the system continuously records the change trajectory of the tower base tilt angle data at a high-frequency sampling rate. The system monitors whether the tilt angle value can fall back to a small deviation range from the initial reading (i.e., physical zero point ± allowable error) and performs the following judgment process: Judgment Logic C (Medium Risk Interception): If, after time T1, the dip angle data fails to return to the specified range or exhibits a stepped non-zeroing phenomenon, this indicates that the foundation soil layer or foundation ring has undergone plastic deformation or significant hysteresis, i.e., foundation loosening. In this case, the system determines it as "medium risk" and terminates the assessment process.

[0038] Judgment Logic D (Test Passed): If the tilt angle data smoothly falls back to the initial deviation range within time T1, exhibiting good elastic recovery characteristics, it indicates that the foundation and subgrade are tightly connected and meet the conditions for conducting higher-level seismic tests. At this time, the system outputs a "pass" signal, allowing the logic controller to jump to step S3.

[0039] In the above process, the prior determination of static tilt acts as a circuit breaker. Existing technologies often perform whole-machine modeling and analysis without distinguishing the foundation condition. However, in this invention, once the static tilt angle of the foundation is found to exceed the standard, subsequent test steps such as large-amplitude pitch changes or active vibrations, which may bring stronger loads, are immediately terminated. This effectively prevents the risk of tower collapse caused by forcibly applying test loads to units with existing foundation settlement risks. In addition, this invention generates torque pulses by actively controlling yaw, forcing the foundation to bear force. This dynamic rebound logic can accurately identify those falsely healthy units that are level when stationary but undergo plastic displacement when subjected to force, significantly improving the authenticity and accuracy of seismic assessment. By strictly determining the tower base (step S2), then the tower (step S3), and finally the damping (step S4), this invention achieves physical-level fault decoupling. If the assessment has already terminated in step S2, maintenance personnel can directly determine that the problem lies in the foundation or foundation ring without checking the tower bolts or dampers, greatly narrowing the scope of fault diagnosis and improving operation and maintenance efficiency.

[0040] In an embodiment of the present invention, after step S2 is executed, the method of the present invention executes step S3. Specifically, step S3 is used to evaluate the resistance to deformation (stiffness) of the wind turbine tower and connecting components (such as flanges and bolts) under horizontal loads, as well as the resilience of the materials. This step utilizes natural wind as the loading source and the wind turbine's own pitch mechanism as the loading controller.

[0041] First, the control system issues a command to lock the generator rotor of the wind turbine, putting it into a non-rotating power generation state. Then, the control yaw system activates, precisely aligning the nacelle with the current prevailing wind direction based on the wind vane signal on the top of the nacelle, to ensure that the wind load can act perpendicularly to the normal direction of the wind turbine plane, thereby generating maximum horizontal thrust on the tower.

[0042] After yaw alignment, the control system sends a command to the pitch system, driving the three blades to synchronously adjust from the full feathering position (0 angle of attack) to the preset maximum thrust position (usually a plane position close to 0 degrees pitch angle; the specific angle depends on the aerodynamic characteristics of the turbine blades, with the aim of maximizing the drag coefficient). At this time, natural wind blows across the stationary rotor, generating continuous physical thrust on the tower, simulating the horizontal shear force in an earthquake. While maintaining the maximum thrust position, the system enters a monitoring and judgment cycle.

[0043] Specifically, the system continuously monitors real-time wind speed. A data recording command is triggered only when the wind speed remains within the fluctuation range of the test wind speed Vtest (e.g., Vtest ± 1 m / s) for a preset time period Tstab (e.g., 30 seconds). This ensures the constancy of the loading force and avoids interference from gusts. After triggering the recording command, the system reads the horizontal displacement Dtop relative to the tower base reference point from the displacement sensor installed at the top of the tower (or obtained via dual-differential GPS). The system directly compares the measured displacement Dtop with the preset stiffness limit threshold Dlimit. If Dtop > Dlimit, this means that the tower has experienced bending deformation exceeding the design allowable under standard wind load. This indicates a significant degradation in the overall stiffness of the tower structure (e.g., large-area loosening of tower flange bolts, weld cracking leading to structural stiffness reduction). In this case, the system immediately determines the result as "insufficient stiffness" and forcibly outputs an alarm signal, ceasing subsequent unloading and rebound tests to prevent further structural damage. If Dtop≤Dlimit, it indicates that the stiffness of the tower under static stress is within a safe range. The system outputs a "static qualified" signal and automatically triggers the next step of the unloading test.

[0044] After passing the static stiffness test, the system immediately performs a step unloading operation to test the tower's elastic recovery capability. Specifically, the control system sends a high-priority emergency feathering command to the pitch actuator. The blades rapidly rotate from the maximum thrust position to the 90-degree full feathering position at the maximum pitch rate (e.g., 5 degrees / second or higher). This action is physically equivalent to instantly removing the enormous horizontal thrust acting on the top of the tower. The system's internal timer starts (Tstart) the instant the pitching action begins. Simultaneously, the system acquires high-frequency tower top displacement data, monitoring the process of the tower swinging back from a bent state to physical zero point (i.e., the no-load position established in step S1).

[0045] When the displacement data first returns to the dead zone near the physical zero point, the timer stops and records the time difference at this time as the actual rebound time Treturn. The system compares this time with the preset standard rebound time Tstd (based on the theoretical inherent period setting of an intact tower) and the allowable error ΔT.

[0046] If Treturn > (Tstd + ΔT), it means the rebound time is too long. This indicates a hysteresis effect in the structure. This is usually not caused by stiffness (elastic modulus), but by structural softening, cumulative material damage, or microslippage at joints (increased frictional energy loss). Based on this, the system determines that the structure has a "structural softening / aging" trend.

[0047] If the Treturn is within the allowable range, it means that the tower not only has sufficient stiffness but also maintains good linear elastic characteristics, and this step is judged to be "qualified" overall.

[0048] As can be seen, in the above process, this invention utilizes the cooperation of natural wind and the pitch system to generate a horizontal thrust of up to tens of tons (simulating seismic force) in situ on the wind turbine, thereby achieving a real-load test of the overall stiffness of the tower under actual working conditions. Furthermore, by setting static stiffness logic gates and dynamic rebound logic gates, and establishing a strict dependency relationship (dynamic rebound is only allowed if the static displacement does not exceed the limit), this design avoids forcibly conducting violent dynamic unloading tests when the structure is already severely loose (insufficient stiffness), preventing safety accidents such as tower collapse caused by the testing process itself, demonstrating extremely high engineering safety. Moreover, this scheme accurately characterizes stiffness through the displacement Dtop and characterizes the hysteresis of the structure's dynamic response (structural aging / softening) through the rebound time Treturn. This decoupling of physical quantities allows maintenance personnel to accurately determine whether to tighten bolts (addressing stiffness issues) or assess tower life (addressing aging issues). Furthermore, the entire process does not rely on complex finite element model inversion or neural network prediction; all judgments are based on intuitive physical quantities, making the evaluation report easily understandable to maintenance personnel.

[0049] Next, step S4 is triggered only if the result of step S3 (tower structure stiffness assessment) is "qualified". Its core lies in abandoning the complex damping ratio calculation formula and instead, by actively creating controlled physical disturbances, directly counting the number of physical oscillations during the unit's return to calm, using this as a quantitative evaluation basis for damping performance. Specifically, this step can be divided into the following sub-stages: 1. Active Excitation and Safety Threshold Monitoring Phase: In this phase, the system switches from passive monitoring mode to active excitation mode, artificially inputting energy into the wind turbine through control logic to induce vibration. Specifically, the system first detects the current turbine status. If the turbine is shut down and the grid connection is normal, the system controls the generator converter to apply a reverse torque pulse (i.e., braking action) to the generator rotor for a preset duration (e.g., 0.5 seconds). This pulse utilizes the tower's flexibility to generate an instantaneous inertial force at the tower top, inducing the tower to sway back and forth. If the turbine is in standby idling state, the system controls the pitch actuator to drive the blades to perform periodic micro-pitch adjustments (e.g., reciprocating between +1 degree and -1 degree) at the tower's first natural frequency (this frequency is a factory preset value, not a real-time calculated value). The periodic changes in aerodynamic thrust will cause resonance in the tower.

[0050] While performing the above excitation actions, the system monitors the data of the acceleration sensor or displacement sensor installed on the tower top in real time at a high frequency (e.g., 100 Hz), and calculates its real-time vibration amplitude Areal. The system compares Areal with the preset test safety amplitude Atest in real time. Once Areal≥Atest (indicating that the vibration amplitude has reached the signal-to-noise ratio requirement for evaluation and has not endangered the structural safety), the control system immediately forcibly cuts off the above excitation source (stops the torque pulse or stops the pitch swing), and locks the blade and yaw system, making the wind turbine enter a complete free decay vibration state.

[0051] 2. Period counting stage of the free decay process: In this stage, the vibration of the unit gradually weakens under its own damping. The system no longer performs control actions but instead conducts counting statistics. The system locks the data acquisition interval, with the starting point being the moment when the vibration amplitude first starts to decline from the peak, and the ending point being the moment when the vibration amplitude decays to Afinal (where Afinal is preset to be one-tenth of Atest, i.e., 10%). Within the above interval, the system detects the number of times the vibration waveform crosses the zero point (or the equilibrium position) and returns to the same-direction peak each time. The system records the complete number of vibration cycles in this process through a counter, denoted as Ncycle.

[0052] 3. Multilevel logic determination stage of damping performance: The system reads the counter value Ncycle and places it in the preset damping evaluation interval for logical comparison: Low damping (seismic hazard) determination: If Ncycle>Nmax (where Nmax is the low damping warning value, e.g., set to 50 cycles), this means that the unit still cannot stop shaking for a long time. During an earthquake, this characteristic will cause the energy to not dissipate,极易引发破坏性共振. At this time, the seismic damping performance is determined to be "poor", and an alarm is triggered.

[0053] Abnormal damping (mechanical failure) determination: If Ncycle<Nmin (where Nmin is the over-damping warning value, e.g., set to 3 cycles), this means that the unit almost immediately stops moving after the excitation stops. This is usually not because of good seismic performance but means that there are abnormal mechanical frictions, bearing jams, or hydraulic damper failures (excessive damping) in the system, resulting in a rigid structure. At this time, it is determined as "abnormal damping", and a mechanical inspection is prompted.

[0054] Good damping (qualified) determination: If Nmin≤Ncycle≤Nmax, it means that the unit can dissipate the vibration energy within a reasonable number of cycles, without resonance risk or mechanical jamming. At this time, the seismic damping performance is determined to be "excellent".

[0055] It should be noted that there is an unclear expression "极易引发破坏性共振" in the original text, and I have tried my best to translate it according to the context. You may need to check and adjust it according to the actual situation.This method directly uses the intuitive physical quantity of vibration cycles (Ncycle) as the basis for judgment, avoiding complex floating-point calculations and model assumptions. It boasts strong anti-interference capabilities, and the evaluation results are logically clear and readily understandable for frontline maintenance personnel. Furthermore, the active excitation logic (pitch control or generator torque) means that even in calm weather conditions with no wind or light breezes, the key seismic performance of the unit, namely the damper performance, can be checked at any time, greatly improving the timeliness and proactivity of the assessment. Further, by setting bidirectional thresholds (Nmax and Nmin), this invention can not only identify seismic risks caused by insufficient damping (excessive Ncycle) but also identify abnormally excessive damping caused by mechanical jamming (excessive Ncycle). This is a blind spot often overlooked by traditional seismic assessment methods, avoiding the misjudgment of mechanical faults as excellent seismic performance. Moreover, due to the specially set safety cutoff logic (Areal ≥ Atest, immediate stop), it ensures that during active disturbance testing, artificially generated vibrations are controlled within the safe range of the design strength, preventing fatigue damage or destruction of the wind turbine unit due to the testing operation itself.

[0056] Furthermore, in embodiments of the present invention, a step of verifying the differences of key nodes is also included. Specifically, upper and lower monitoring points at the tower section flange are selected, and their displacement data during the test is read. Then, the absolute value of the difference between the displacement data of the upper monitoring point and the displacement data of the lower monitoring point is calculated. If the absolute value is greater than a preset flange misalignment threshold, the flange location is marked as having a weak point in seismic resistance.

[0057] Specifically, during the wind turbine installation or evaluation preparation phase, micro-displacement sensors need to be installed at key connection points on the tower, namely at segment flanges (e.g., bottom flange, intermediate flange). The upper monitoring point has the sensor fixed to the tower wall above the flange connection surface, and the lower monitoring point has the sensor fixed to the tower wall below the flange connection surface. When the system is in the maximum thrust holding phase (step S3) or the free decay vibration phase (step S4), the system control data acquisition unit is synchronously triggered. This ensures that the displacement values ​​Sup(t) of the upper monitoring point and Sdown(t) of the lower monitoring point are read at the same time t. Both values ​​must be physical quantities at the same timestamp to eliminate errors caused by time delays.

[0058] After receiving two displacement signals, the system does not perform any frequency domain transformation or complex filtering algorithm processing, but directly performs physical difference calculation.

[0059] The calculation formula is: Sdiff = |Sup(t) - Sdown(t)|.

[0060] Here, Sdiff represents the relative displacement of the upper and lower parts of the tower at the instant of force application on the flange connection surface. Under ideal physical connection conditions (i.e., the bolt tightening torque is fully compliant), the tower should behave as a continuous rigid body, and this difference should theoretically approach zero or contain only a small amount of elastic deformation of the metallic material.

[0061] The system performs a logical comparison between the calculated Sdiff and the flange misalignment threshold Sgap preset in the controller's storage unit. Sgap is the maximum allowable elastic slip based on flange design specifications.

[0062] Logical Branch 1 (Qualified): If Sdiff ≤ Sgap, it indicates that under the current active disturbance load, the upper and lower tower sections of the flange maintain consistent motion, the connection is tight, and no relative slippage occurs. At this point, the system marks this node as "structurally intact" and continues the subsequent process.

[0063] Logic Branch Two (Hidden Danger Assessment): If Sdiff > Sgap, it indicates that a relative displacement exceeding the design allowable range has occurred at the flange connection. Physically, this means a decrease in the preload of the connecting bolts, resulting in insufficient friction to resist shear force, leading to gapping or misalignment. At this point, the system immediately generates a "seismic weak point" marker and records the specific flange number (e.g., "Flange Section 2 Abnormal").

[0064] Regardless of the overall stiffness assessment (step S3) results, this marker will be passed to the final report as the highest priority maintenance instruction.

[0065] In this way, this step can directly locate the specific flange level by using the physical difference logic between the upper and lower monitoring points. This eliminates the need for maintenance personnel to blindly inspect hundreds or thousands of bolts; they only need to perform torque checks on the specific marked flange, greatly improving the efficiency of seismic reinforcement. In addition, this step is independent of the overall assessment and specifically checks the continuity of connections, effectively capturing local conditions that are easily masked by the overall assessment.

[0066] Finally, in step S5, the system will integrate the judgment results of steps S2 to S4 and output the final seismic performance rating and corresponding control strategy of the wind turbine according to the preset decision logic.

[0067] Specifically, the system first reads the following status flags from memory: Foundation status marker (derived from step S2): possible values ​​are "qualified", "high risk (static tilt exceeds standard)" and "medium risk (dynamic rebound fails)".

[0068] Stiffness status label (derived from step S3): possible values ​​are "qualified", "insufficient stiffness (displacement exceeds limit)" and "structural softening (springback hysteresis)".

[0069] Damping status label (derived from step S4): possible values ​​are “Excellent”, “Poor (too slow decay)”, and “Abnormal (too fast decay)”.

[0070] Node integrity flag (derived from the difference verification step): possible values ​​are "qualified" and "weak point exists (flange misalignment)".

[0071] Next, following the principles of safety first and tiered response, the system executes the following logical checks sequentially. Once a high-priority fault condition is met, the output is immediately locked, and subsequent low-priority checks are not executed: Level 1 Assessment (Foundation and Tower Collapse Risk Assessment): The system first checks the foundation status marker. If the marker is "High Risk" or "Medium Risk," it indicates that the wind turbine's foundation is unstable, posing a real risk of tower collapse. The system immediately sends a highest-priority "Emergency Shutdown" command to the wind turbine's main control system and locks the yaw and pitch systems to prevent any disturbance. Simultaneously, it sends a "Red Alert: Foundation Failure" to the remote monitoring center and outputs a maintenance strategy of "Prohibit Operation, Immediately Reinforce the Foundation."

[0072] Second-level judgment (structural integrity judgment): If the first-level judgment passes (i.e., the foundation is qualified), the system then checks the stiffness status marker. If the marker is "insufficient stiffness" or "structural softening," it indicates that the tower body may have serious bolt loosening, weld cracking, or material fatigue, making it unable to withstand rated wind loads or seismic shear forces. The system sends a "normal shutdown" command (smooth feathering shutdown to avoid secondary damage from emergency braking). An "orange alert: abnormal structural stiffness" is sent to the monitoring center, and a maintenance strategy of "shutdown and maintenance, comprehensive inspection of tower bolt torque and welds" is output.

[0073] Level 3 Judgment (Energy Dissipation and Seismic Resistance Judgment): If the first two levels pass, the system checks the damping status marker. If the marker is "Poor," it indicates that the unit's damper has failed or its aerodynamic damping characteristics have deteriorated. Although the static structure is safe, it is highly susceptible to large-amplitude resonance under earthquake or strong wind conditions, and it is difficult to stop. The system does not require shutdown, but sends a "Power Limit (Derating Operation)" command to limit the turbine speed to avoid the resonance frequency region. At the same time, it sends a "Yellow Alert: Damping Performance Deteriorates" and outputs a strategy of "Limited Power Operation, Damper or TMD System Maintenance Required."

[0074] Level 4 Judgment (Local Hazard Judgment): If the first three levels pass, the system checks the node integrity marker. If the marker is "Weak Point Exists," it indicates that the overall performance is acceptable, but there is a risk of microscopic misalignment on a specific flange surface. The system maintains the wind turbine in "normal power generation" status, but automatically generates a work order in the operation and maintenance management system, outputting the strategy of "normal operation, but the inspection cycle of flange number XX needs to be shortened by 50%."

[0075] Level 5 Judgment (Excellent Judgment): If all the above judgment conditions are "No" (i.e. all marks are qualified / excellent), the system outputs a rating of "excellent seismic performance" and suggests "maintaining the current maintenance strategy", without manual intervention.

[0076] Therefore, this step, through hierarchical logic, clearly distinguishes between situations requiring immediate shutdown (e.g., foundation problems) and those that can be operated with reduced capacity (e.g., damping problems). This prevents both power generation losses due to a complete shutdown caused by minor issues (over-maintenance) and tower collapse accidents caused by forced operation under critical hidden dangers (e.g., loose foundations) (safety negligence). This step directly translates the physical assessment results into specific operating condition control commands (emergency shutdown, reduced capacity, normal operation). This means that the assessment system can be directly connected to the wind farm's main control system (SCADA) to achieve closed-loop control. It eliminates the need for secondary analysis of complex data maps by experts, significantly reducing reliance on seismic assessment professionals. Compared to predictions given by AI algorithms (e.g., AI indicates an 80% probability of failure but doesn't know the cause), each output of this step is supported by a clear chain of physical evidence (e.g., because the rebound time T>Tstd, it is judged as structural softening, therefore a shutdown is executed). This clear causal relationship makes the goals of maintenance personnel extremely clear when performing maintenance, improving maintenance efficiency.

[0077] On the other hand, such as Figure 2 As shown, the present invention also provides an in-situ evaluation system for the seismic performance of wind turbine generators, which can be referred to in conjunction with the method described above. The system includes: The environment and status preset screening module performs logical screening on the current operating environment and equipment status of the wind turbine. When the judgment result is that the preset conditions are met, the physical zero point of evaluation is established and the foundation stability logic judgment module is triggered. The foundation stability logic judgment module judges the foundation stability through data from dual-axis tilt sensors. If the judgment result is qualified, it applies a disturbance by controlling the yaw system to conduct a dynamic rebound test. Based on the test result, it decides whether to trigger the tower structure stiffness response analysis module. The tower structure stiffness response analysis module uses natural wind as a loading source to control the pitch system to test the tower structure stiffness. The stiffness logic gate judges the stiffness through the physical quantity feedback of the displacement sensor. If the judgment is qualified, the system damping active disturbance test module is triggered. The system damping active disturbance test module actively generates vibration by controlling the generator or pitch system, monitors the free decay process after the excitation stops, and determines the system damping energy dissipation capacity based on the number of vibration cycles. The seismic performance comprehensive rating output module integrates the judgment results of the above modules and outputs the final seismic performance rating and corresponding control strategy of the wind turbine according to the preset decision logic.

[0078] Figure 3 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 3 As shown, the electronic device may include a processor 810, a communications interface 820, a memory 830, and a communication bus 840. The processor 810, communications interface 820, and memory 830 communicate with each other via the communication bus 840. The processor 810 can call logical instructions from the memory 830 to execute an in-situ assessment method for the seismic performance of wind turbine generators.

[0079] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0080] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the in-situ evaluation method for the seismic performance of wind turbine units provided by the above methods.

[0081] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the in-situ evaluation method for the seismic performance of wind turbine units provided by the methods described above.

[0082] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0083] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for in-situ evaluation of the seismic performance of wind turbine generators, characterized in that, include: Step S1: Perform logical screening on the current operating environment and equipment status of the wind turbine. If the judgment result is that the preset conditions are met, establish the physical zero point for evaluation and proceed to step S2. Step S2: Determine the foundation stability using data from the dual-axis tilt sensor. If the determination result is satisfactory, apply a disturbance by controlling the yaw system to conduct a dynamic rebound test. Determine whether to proceed to step S3 based on the test results. Step S3: Using natural wind as a loading source, control the pitch system to test the stiffness of the tower structure. The stiffness logic gate judges the stiffness by the physical quantity feedback of the displacement sensor. If the judgment is qualified, proceed to step S4. Step S4: Actively generate vibration by controlling the generator or pitch system, monitor the free decay process after stopping the excitation, and determine the system's damping energy dissipation capacity based on the number of vibration cycles; Step S5: Based on the judgment results of steps S2 to S4, output the final seismic performance rating and corresponding control strategy of the wind turbine according to the preset decision logic.

2. The in-situ evaluation method for the seismic performance of wind turbine generators according to claim 1, characterized in that, The logical screening step in step S1 specifically includes: Collect real-time wind speed and unit operating status signals; Determine whether the real-time wind speed is within the preset test safety range, and at the same time determine whether the unit is in a fault-free standby or low-load operation state; If all judgment results are "yes", then lock the unit's yaw system and control the pitch system to adjust the blade angle to the full feather position to establish the physical zero point; If any judgment result is "no", an environmental condition non-compliance signal will be output and the evaluation process will be terminated.

3. The in-situ evaluation method for the seismic performance of wind turbine generators according to claim 2, characterized in that, The step of determining foundation stability in step S2 specifically includes: Read the X-axis tilt angle and Y-axis tilt angle values ​​at the bottom of the tower; The absolute values ​​of the X-axis tilt angle and the Y-axis tilt angle are compared with preset static safety thresholds, respectively. If any absolute value is greater than the static safety threshold, the seismic resistance level is determined to be high-risk and subsequent steps are terminated. If both absolute values ​​are less than the static safety threshold, then the dynamic rebound test is performed.

4. The in-situ evaluation method for the seismic performance of wind turbine generators according to claim 3, characterized in that, The steps of the dynamic rebound test specifically include: The nacelle is rotated by a preset angle to generate a torque disturbance, and then the yaw action is stopped; Monitor whether the tower base tilt angle data recovers to within the deviation range of the initial value within a preset time after the yaw action stops; If the result is "no", it is determined that there is a risk of the foundation becoming loose, and the process is terminated; If the result is "yes", the foundation condition is deemed qualified, and the process can proceed to step S3.

5. The in-situ evaluation method for the seismic performance of wind turbine generators according to claim 4, characterized in that, Step S3 specifically includes: The nacelle is aligned with the wind direction, and the blade pitch angle is simultaneously opened to the maximum thrust position. When the wind speed is stable, detect the real-time displacement of the top of the tower. If the real-time displacement is greater than the preset stiffness limit threshold, the tower stiffness is determined to be insufficient, the result is recorded and the subsequent logic of step S3 is skipped. If the real-time displacement does not exceed the stiffness limit threshold, then the unloading and springback determination step is executed.

6. The in-situ evaluation method for the seismic performance of wind turbine generators according to claim 5, characterized in that, The unloading and rebound determination step specifically includes: Control the pitch system to perform an emergency feathering maneuver to simulate load removal; Record the actual rebound time required for the tower position to return to physical zero; Compare the actual rebound time with the preset standard rebound time; If the actual rebound time is greater than the sum of the standard rebound time and the allowable error, the structure is judged to have a softening trend. If the actual rebound time is within the allowable range, the tower stiffness is deemed qualified, and the process proceeds to step S4.

7. The in-situ evaluation method for the seismic performance of wind turbine generators according to claim 6, characterized in that, The step of actively generating vibration in step S4 specifically includes: When the unit is shut down, control the generator to apply a short-term reverse torque pulse, or control the pitch system to perform periodic pitch changes at the first natural frequency of the tower. When the monitored vibration amplitude at the top of the tower reaches the preset test safety amplitude, the excitation action is immediately stopped, allowing the wind turbine to enter a free decay vibration state.

8. The in-situ evaluation method for the seismic performance of wind turbine generators according to claim 7, characterized in that, The step of determining the system's damping energy dissipation capacity in step S4 specifically includes: The number of vibration cycles that occur when the vibration amplitude decays from the test safety amplitude to one-tenth of that amplitude is collected; If the number of vibration cycles is greater than the preset low damping warning value, the seismic damping performance is determined to be poor. If the number of vibration cycles is less than the preset overdamping warning value, it is determined to be abnormal damping; If the number of vibration cycles is between the overdamping warning value and the underdamping warning value, the seismic damping performance is determined to be excellent.

9. The in-situ evaluation method for the seismic performance of wind turbine generators according to claim 8, characterized in that, Step S5 specifically includes: If step S2 determines that there is a high risk or a risk of foundation loosening, output a strategy to prohibit operation and reinforce the foundation; If step S3 determines that the stiffness is insufficient, output a strategy of stopping the machine for maintenance and checking the bolt torque; If step S4 determines that the seismic damping performance is poor, a strategy of limiting power operation and maintaining the damper is output. If all the above steps are successful but there are weak points in seismic resistance, output a strategy to ensure normal operation and shorten the inspection cycle; If all criteria are met, output "Maintain the current maintenance strategy".

10. An in-situ evaluation system for the seismic performance of wind turbine generators, characterized in that, include: The environment and status preset screening module performs logical screening on the current operating environment and equipment status of the wind turbine. When the judgment result is that the preset conditions are met, the physical zero point of evaluation is established and the foundation stability logic judgment module is triggered. The foundation stability logic judgment module judges the foundation stability through data from dual-axis tilt sensors. If the judgment result is qualified, it applies a disturbance by controlling the yaw system to conduct a dynamic rebound test. Based on the test result, it decides whether to trigger the tower structure stiffness response analysis module. The tower structure stiffness response analysis module uses natural wind as a loading source to control the pitch system to test the tower structure stiffness. The stiffness logic gate judges the stiffness through the physical quantity feedback of the displacement sensor. If the judgment is qualified, the system damping active disturbance test module is triggered. The system damping active disturbance test module actively generates vibration by controlling the generator or pitch system, monitors the free decay process after the excitation stops, and determines the system damping energy dissipation capacity based on the number of vibration cycles. The seismic performance comprehensive rating output module integrates the judgment results of the above modules and outputs the final seismic performance rating and corresponding control strategy of the wind turbine according to the preset decision logic.

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