Unbalanced blade identification method
By combining the damping parameters and vibration signals of the wind turbine generator set, the initial phase angle and the peak phase difference of the unbalanced excitation are determined, which solves the problem of complex and inefficient identification of wind turbine generator set impeller imbalance in the existing technology and realizes fast and simplified blade identification.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SANY ELECTRIC CO LTD
- Filing Date
- 2024-03-01
- Publication Date
- 2026-07-24
AI Technical Summary
Existing methods for identifying wind turbine rotor imbalance are complex and have low efficiency, requiring each blade to be inspected separately.
By acquiring the damping parameters and vibration signals of the wind turbine generator set, and combining them with the azimuth waveform of the impeller, the initial phase angle and the peak phase difference of the unbalanced excitation are determined, and the unbalanced blades are identified using the actual phase angle.
It enables rapid identification of unbalanced blades in a single measurement, improving identification efficiency and simplifying the detection process.
Smart Images
Figure CN117869226B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wind turbine rotor imbalance identification technology, and in particular to a method for identifying unbalanced blades. Background Technology
[0002] Imbalance in wind turbine rotors mainly includes two aspects: mass imbalance (vibration of the nacelle in the left-right direction) and aerodynamic imbalance (vibration of the nacelle in the front-back direction). In actual operation, either type of imbalance will cause large-amplitude vibrations to the wind turbine, including nacelle vibration along the wind direction, nacelle lateral vibration, and nacelle torsional vibration, which will endanger the life and safety of the wind turbine.
[0003] Therefore, identifying the location of unbalanced blades on the impeller and replacing or adjusting them in a timely manner is of great significance to wind turbine generators. However, existing methods for identifying unbalanced blades are relatively complex, requiring each blade to be inspected separately, resulting in low identification efficiency. Summary of the Invention
[0004] The main objective of this invention is to propose a method for identifying unbalanced blades, aiming to solve the problems of existing methods for identifying unbalanced wind turbine rotors being complex and having low identification efficiency.
[0005] To achieve the above objectives, the unbalanced blade identification method proposed in this invention is based on a wind turbine generator set, and the unbalanced blade identification method includes the following steps:
[0006] Obtain the damping parameters of the wind turbine generator set, and after starting the wind turbine generator set, obtain the vibration signal of the nacelle and the azimuth waveform of the rotor.
[0007] Based on the vibration signal and the azimuth waveform, the initial phase angle when the impeller amplitude reaches its peak value is determined, and the unbalanced excitation peak phase difference is determined based on the damping parameters.
[0008] The actual phase angle is determined based on the phase difference between the unbalanced excitation peak and the initial phase angle, and the unbalanced blade is identified based on the actual phase angle.
[0009] In some embodiments, the phase difference of the unbalanced excitation peak is α1;
[0010] The initial phase angle is α2;
[0011] The actual phase angle is α3;
[0012] Where α3 = α2 - α1.
[0013] In some embodiments, determining the unbalanced excitation peak phase difference based on the damping parameter includes:
[0014] The unbalanced excitation waveform and vibration phase waveform are determined based on the damping parameters.
[0015] Determine the phase difference between the unbalanced excitation peak value and the peak value of the unbalanced excitation waveform on the vibration phase waveform.
[0016] In some embodiments, determining the initial phase angle at which the impeller amplitude reaches its peak value based on the vibration signal and the azimuth waveform includes:
[0017] Determine the unbalanced vibration waveform based on the vibration signal;
[0018] Determine the initial phase angle on the azimuth waveform that corresponds to the peak of the unbalanced vibration waveform.
[0019] In some embodiments, the unbalanced vibration waveform includes an impeller axial vibration waveform;
[0020] The initial phase angle includes the initial axial phase angle;
[0021] The actual phase angle includes the actual axial phase angle;
[0022] The step of determining the actual phase angle based on the unbalanced excitation peak phase difference and the initial phase angle, and identifying the unbalanced blade based on the actual phase angle, includes:
[0023] The actual axial phase angle is determined based on the phase difference between the unbalanced excitation peak and the initial axial phase angle, and the aerodynamic unbalanced blade is identified based on the actual axial phase angle.
[0024] In some embodiments, the unbalanced vibration waveform includes an impeller radial vibration waveform;
[0025] The initial phase angle includes the initial radial phase angle;
[0026] The actual phase angle includes the actual radial phase angle;
[0027] The step of determining the actual phase angle based on the unbalanced excitation peak phase difference and the initial phase angle, and identifying the unbalanced blade based on the actual phase angle, includes:
[0028] The actual radial phase angle is determined based on the phase difference of the unbalanced excitation peak and the initial radial phase angle, and the unbalanced blade is identified based on the actual radial phase angle.
[0029] In some embodiments, the impeller radial vibration waveform includes a vibration waveform in the radial direction perpendicular to the wind turbine tower.
[0030] In some embodiments, determining the unbalanced vibration waveform based on the vibration signal includes:
[0031] The impeller rotational speed is obtained, and the vibration signal is frequency filtered according to the rotational speed to obtain an unbalanced vibration waveform.
[0032] In some embodiments, the frequency of the unbalanced vibration waveform is one-sixtieth of the rotational speed.
[0033] In some embodiments, the steps prior to acquiring the damping parameters of the wind turbine generator set and, after starting the wind turbine generator set, acquiring the vibration signal of the nacelle and the azimuth waveform of the rotor include:
[0034] An acceleration sensor is installed in the nacelle, and an azimuth measuring device is installed in the impeller.
[0035] The acquisition of the vibration signal of the nacelle and the azimuth waveform of the impeller includes:
[0036] Vibration signals from the nacelle are acquired using an accelerometer, and the azimuth waveform of the impeller is obtained using an azimuth measurement device.
[0037] In the technical solution provided by this invention, by acquiring the vibration signal and the azimuth waveform, the rotational position of the impeller and the vibration of the nacelle can be correlated in time, thereby determining the initial phase angle of the impeller at the peak vibration moment. Simultaneously, considering the influence of the damping of the wind turbine on the impeller position, the phase difference of the unbalanced excitation peak is determined by acquiring the damping parameters. The actual phase angle of the unbalanced blade can be determined by the initial phase angle and the phase difference of the unbalanced excitation peak, thus determining the position of the unbalanced blade. In this solution, the identification of the unbalanced blade can be completed with a single measurement, making the method relatively simple and significantly improving the identification efficiency of the unbalanced blade. Attached Figure Description
[0038] To more clearly illustrate the technical solutions in the embodiments of the present 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0039] Figure 1 A flowchart of a first embodiment of the unbalanced blade identification method provided by the present invention;
[0040] Figure 2 This is a flowchart of a second embodiment of the unbalanced blade identification method provided by the present invention.
[0041] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0042] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0043] It should be noted that if the embodiments of the present invention involve directional indication, the directional indication is only used to explain the relative positional relationship and movement of the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.
[0044] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.
[0045] Imbalance in wind turbine rotors mainly includes two aspects: mass imbalance (vibration of the nacelle in the left-right direction) and aerodynamic imbalance (vibration of the nacelle in the front-back direction). In actual operation, either type of imbalance will cause large-amplitude vibrations to the wind turbine, including nacelle vibration along the wind direction, nacelle lateral vibration, and nacelle torsional vibration, which will endanger the life and safety of the wind turbine.
[0046] Therefore, identifying the location of unbalanced blades on the impeller and replacing or adjusting them in a timely manner is of great significance to wind turbine generators. However, existing methods for identifying unbalanced blades are relatively complex, requiring each blade to be inspected separately, resulting in low identification efficiency.
[0047] Analysis of the above problems shows that the reason for the low recognition efficiency is that each blade needs to be detected separately. However, by combining the vibration signal of the nacelle and the impeller azimuth angle signal, the position of the unbalanced blade can be analyzed after a single measurement.
[0048] In view of this, the present invention proposes an unbalanced blade identification method, aiming to solve the problems of the complexity and low efficiency of existing methods for identifying unbalanced wind turbine rotors. Figure 1 This is a schematic diagram of an embodiment of the unbalanced blade identification method provided by the present invention.
[0049] Please participate Figure 1 and Figure 2 The unbalanced blade identification method proposed in this invention is based on wind turbine generator sets, and includes the following steps:
[0050] S10. Obtain the damping parameters of the wind turbine generator set, and after starting the wind turbine generator set, obtain the vibration signal of the nacelle and the azimuth waveform of the rotor.
[0051] There are many ways to obtain the damping parameters of a wind turbine generator set, such as through actual testing or simulation. There are also many ways to obtain the vibration signal of the nacelle and the azimuth waveform of the rotor, such as through various sensors or detection devices. This embodiment does not limit the specific operation method for obtaining the damping parameters, vibration signal and azimuth waveform.
[0052] S20. Based on the vibration signal and azimuth waveform, determine the initial phase angle when the impeller amplitude reaches its peak value, and determine the unbalanced excitation peak phase difference based on the damping parameters.
[0053] Among them, the azimuth waveform can reflect the position of the impeller at different times, and the vibration signal can reflect the vibration amplitude of the nacelle at different times. By correlating the azimuth waveform with the vibration signal in time, we can know the data on the azimuth waveform corresponding to the moment when the amplitude of the nacelle reaches its peak, which is the initial phase angle of the impeller. In an ideal situation, the initial phase angle can reflect the position of the unbalanced blades of the impeller. However, in actual situations, we also need to consider the influence of the damping of the wind turbine on the vibration of the nacelle. Therefore, it is necessary to obtain the peak phase difference of the unbalanced excitation. It should be noted that the peak phase difference of the unbalanced excitation refers to the vibration phase difference of the impeller when the unbalanced excitation force reaches its peak.
[0054] S30. Determine the actual phase angle based on the unbalanced excitation peak phase difference and the initial phase angle, and identify the unbalanced blades based on the actual phase angle.
[0055] Because of the damping in the wind turbine generator, the initial phase angle cannot accurately reflect the position of the unbalanced blade. The peak phase difference of the unbalanced excitation, determined by the damping parameters, must also be taken into account to obtain the actual position of the unbalanced blade, i.e., the actual phase angle. It should be noted that...
[0056] In the technical solution provided by this invention, by acquiring vibration signals and azimuth waveforms, the rotational position of the impeller and the vibration of the nacelle can be correlated in time, thereby determining the initial phase angle of the impeller at the peak vibration moment. Simultaneously, considering the influence of the damping of the wind turbine on the impeller position, the phase difference of the unbalanced excitation peak is determined by acquiring damping parameters. The actual phase angle of the unbalanced blade can be determined by the initial phase angle and the phase difference of the unbalanced excitation peak, thus determining the position of the unbalanced blade. In this solution, the unbalanced blade can be identified with a single measurement, making the method relatively simple and significantly improving the identification efficiency of the unbalanced blade.
[0057] In some embodiments, the unbalanced excitation peak phase difference is α1, the initial phase angle is α2, and the actual phase angle is α3, where α3 = α2 - α1. According to the above scheme, since the unbalanced excitation peak phase difference and the initial phase angle are in opposite directions, the actual phase angle can be obtained directly by subtracting the unbalanced excitation peak phase difference from the initial phase angle.
[0058] Please see Figure 2 In some embodiments, determining the peak phase difference of the unbalanced excitation based on damping parameters includes:
[0059] S22a. Determine the unbalanced excitation waveform and vibration phase waveform based on the damping parameters;
[0060] The phase difference between the unbalanced excitation force and the impeller vibration can be directly calculated from the damping parameters, and the unbalanced excitation waveform and vibration phase waveform can be directly obtained. This will not be elaborated further in the embodiments of this application.
[0061] S22b. Determine the phase difference between the peak value of the unbalanced excitation and the peak value of the unbalanced excitation waveform on the vibration phase waveform.
[0062] It should be noted that the magnitude of the unbalanced excitation force is directly related to the real-time position of the unbalanced blade. Although the real-time position of the unbalanced blade cannot be directly determined by the unbalanced excitation force, the unbalanced excitation force will hinder the movement of the impeller. Since the vibration phase difference changes periodically with the unbalanced excitation force, the phase difference of the unbalanced excitation peak corresponding to the peak of the unbalanced excitation waveform on the vibration phase waveform is the vibration phase difference at the peak moment of the unbalanced blade vibration.
[0063] Please see Figure 2 In some embodiments, the initial phase angle at which the impeller amplitude reaches its peak is determined based on the vibration signal and the azimuth waveform, including:
[0064] S21a. Determine the unbalanced vibration waveform based on the vibration signal;
[0065] Generally speaking, vibration signals are relatively chaotic signals. By filtering, the unbalanced vibration waveform in the corresponding direction can be obtained, and the unbalanced vibration waveform can reflect the vibration pattern in that direction.
[0066] S21b Determine the initial phase angle on the azimuth waveform that corresponds to the peak of the unbalanced vibration waveform.
[0067] Among them, the peak of the unbalanced vibration waveform reflects the peak vibration of the nacelle at that moment. The initial phase angle on the azimuth waveform determined at this moment can reflect the position of the impeller rotation at that moment, which is directly related to the identification of unbalanced blades.
[0068] Since wind turbine rotor imbalance includes aerodynamic imbalance, it is necessary to identify the aerodynamic imbalance of the rotor. The main factor affecting aerodynamic imbalance is vibration along the axial direction of the rotor. Therefore, in some embodiments, the unbalanced vibration waveform includes the rotor axial vibration waveform.
[0069] The initial phase angle includes the initial axial phase angle;
[0070] The actual phase angle includes the actual axial phase angle;
[0071] The actual phase angle is determined based on the peak phase difference of the unbalanced excitation and the initial phase angle, and the unbalanced blades are identified based on the actual phase angle, including:
[0072] The actual axial phase angle is determined by the phase difference between the peak and the initial axial phase angle of the unbalanced excitation, and the aerodynamic unbalanced blade is identified based on the actual axial phase angle.
[0073] According to the above technical solution, a bandpass filter can be used to filter out the measurement noise, thereby obtaining the unbalanced vibration waveform corresponding to the 1P frequency, including the targeted rotor axial vibration waveform. Here, the 1P frequency is the rotational frequency of the wind turbine, and the initial phase angle obtained from the rotor axial vibration waveform is the initial axial phase angle. The final actual phase angle is also the actual axial phase angle, thereby completing the identification of aerodynamically unbalanced blades.
[0074] Since wind turbine rotor imbalance includes mass imbalance, it is necessary to identify the rotor mass imbalance. The main factor affecting mass imbalance is vibration along the radial direction of the rotor. Therefore, in some embodiments, the unbalanced vibration waveform includes the rotor radial vibration waveform.
[0075] The initial phase angle includes the initial radial phase angle;
[0076] The actual phase angle includes the actual radial phase angle;
[0077] The actual phase angle is determined based on the peak phase difference of the unbalanced excitation and the initial phase angle, and the unbalanced blades are identified based on the actual phase angle, including:
[0078] The actual radial phase angle is determined based on the phase difference of the unbalanced excitation peak and the initial radial phase angle, and the unbalanced blades are identified based on the actual radial phase angle.
[0079] According to the above technical solution, a bandpass filter can be used to filter out the measurement noise, thereby obtaining the unbalanced vibration waveform corresponding to the 1P frequency, including the targeted rotor radial vibration waveform. Here, the 1P frequency is the rotational frequency of the wind turbine, and the initial phase angle obtained from the rotor radial vibration waveform is the initial radial phase angle. The final actual phase angle is also the actual radial phase angle, thereby completing the identification of the mass-unbalanced blade.
[0080] In the two sets of embodiments described above, the radial vibration waveform and the axial vibration waveform of the impeller can be determined by the same set of vibration signals. Since the phase difference of the peak value of the unbalanced excitation has the same effect on the axial and radial vibrations, the identification of the unbalanced blades and the unbalanced blades can be completed in one measurement, which further improves the identification efficiency.
[0081] More specifically, in some embodiments, the impeller radial vibration waveform includes a vibration waveform in the radial direction perpendicular to the wind turbine tower. It should be noted that the impeller radial vibration waveform determined from the vibration signal is directional; that is, the vibration waveform in the tested impeller radial direction must be retained. Generally, the axial direction refers to the impeller's rotational axis, i.e., the impeller's windward direction, while the radial direction refers to the direction perpendicular to the axial direction. There are several possibilities; in some schemes, the radial direction is horizontal (perpendicular to the wind turbine tower), while in others, it is vertical (same as the wind turbine tower's axial direction). Regardless of which radial direction of the impeller radial vibration waveform is retained, the final calculated initial phase difference represents the position of the impeller's vibration peak in that radial direction, and the actual phase angle of the impeller can be obtained.
[0082] In some embodiments, determining the unbalanced vibration waveform based on the vibration signal includes:
[0083] The impeller rotational speed is obtained, and the vibration signal is frequency filtered according to the rotational speed to obtain the unbalanced vibration waveform.
[0084] By measuring the impeller speed, it is beneficial to perform frequency filtering on the vibration signal. The resulting unbalanced vibration waveform and azimuth waveform can be integrated within one cycle, which makes it easier to determine the corresponding initial phase angle based on the peak value of the unbalanced vibration waveform.
[0085] Furthermore, in some embodiments, the frequency of the unbalanced vibration waveform is one-sixtieth of the rotational speed.
[0086] In some embodiments, prior to the steps of acquiring the damping parameters of the wind turbine generator set and acquiring the vibration signal of the nacelle and the azimuth waveform of the rotor after starting the wind turbine generator set, the following steps are included:
[0087] An acceleration sensor is installed in the nacelle, and an azimuth measuring device is installed in the impeller.
[0088] Acquire vibration signals from the nacelle and azimuth waveforms of the impeller, including:
[0089] Vibration signals from the nacelle are acquired using an accelerometer, and the azimuth waveform of the impeller is obtained using an azimuth measurement device.
[0090] It should be noted that the method of obtaining the azimuth waveform of the impeller is not limited to using an azimuth measuring device. The speed measuring disk hole of the wind turbine can also be blocked as a zero phase to replace the impeller azimuth parameter. The method of obtaining the vibration signal of the nacelle is not limited to using an acceleration sensor. The main shaft bending moment load and impeller displacement deformation data can also be used as substitutes.
[0091] It is worth mentioning that the damping parameters, impeller speed and other data required in this embodiment are all easily obtainable data, and the acceleration sensor or azimuth measuring device required are all devices that come with the wind turbine generator set. Therefore, there is no need to purchase additional measuring devices, which saves operating costs.
[0092] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.
Claims
1. A method for identifying unbalanced blades, based on wind turbine generator sets, characterized in that, The unbalanced blade identification method includes the following steps: Obtain the damping parameters of the wind turbine generator set, and after starting the wind turbine generator set, obtain the vibration signal of the nacelle and the azimuth waveform of the rotor. Based on the vibration signal and the azimuth waveform, the initial phase angle when the impeller amplitude reaches its peak value is determined, and the unbalanced excitation peak phase difference is determined based on the damping parameters. The actual phase angle is determined based on the unbalanced excitation peak phase difference and the initial phase angle, and the unbalanced blade is identified based on the actual phase angle; The phase difference of the unbalanced excitation peak is α1; The initial phase angle is α2; The actual phase angle is α3; Where α3 = α2 - α1; Determining the initial phase angle at which the impeller amplitude reaches its peak based on the vibration signal and the azimuth waveform includes: Determine the unbalanced vibration waveform based on the vibration signal; Determine the initial phase angle on the azimuth waveform that corresponds to the peak of the unbalanced vibration waveform; The unbalanced vibration waveform includes the impeller axial vibration waveform; The initial phase angle includes the initial axial phase angle; The actual phase angle includes the actual axial phase angle; The step of determining the actual phase angle based on the unbalanced excitation peak phase difference and the initial phase angle, and identifying the unbalanced blade based on the actual phase angle, includes: The actual axial phase angle is determined based on the phase difference between the unbalanced excitation peak and the initial axial phase angle, and the aerodynamic unbalanced blade is identified based on the actual axial phase angle.
2. The method for identifying unbalanced blades as described in claim 1, characterized in that, The step of determining the unbalanced excitation peak phase difference based on the damping parameters includes: The unbalanced excitation waveform and vibration phase waveform are determined based on the damping parameters. Determine the phase difference between the unbalanced excitation peak value and the peak value of the unbalanced excitation waveform on the vibration phase waveform.
3. The method for identifying unbalanced blades as described in claim 1, characterized in that, The unbalanced vibration waveform includes the impeller radial vibration waveform; The initial phase angle includes the initial radial phase angle; The actual phase angle includes the actual radial phase angle; The step of determining the actual phase angle based on the unbalanced excitation peak phase difference and the initial phase angle, and identifying the unbalanced blade based on the actual phase angle, includes: The actual radial phase angle is determined based on the phase difference of the unbalanced excitation peak and the initial radial phase angle, and the unbalanced blade is identified based on the actual radial phase angle.
4. The method for identifying unbalanced blades as described in claim 3, characterized in that, The impeller radial vibration waveform includes vibration waveforms in the radial direction perpendicular to the wind turbine tower.
5. The method for identifying unbalanced blades as described in claim 1, characterized in that, Determining the unbalanced vibration waveform based on the vibration signal includes: The impeller rotational speed is obtained, and the vibration signal is frequency filtered according to the rotational speed to obtain an unbalanced vibration waveform.
6. The method for identifying unbalanced blades as described in claim 5, characterized in that, The frequency of the unbalanced vibration waveform is one-sixtieth of the rotational speed.
7. The method for identifying unbalanced blades as described in claim 1, characterized in that, Before the steps of acquiring the damping parameters of the wind turbine generator set and acquiring the vibration signal of the nacelle and the azimuth waveform of the rotor after starting the wind turbine generator set, the following steps are included: An acceleration sensor is installed in the nacelle, and an azimuth measuring device is installed in the impeller. The acquisition of the vibration signal of the nacelle and the azimuth waveform of the impeller includes: Vibration signals from the nacelle are acquired using an accelerometer, and the azimuth waveform of the impeller is obtained using an azimuth measurement device.