A method for remotely monitoring interlayer structural damage of wind turbine blades

Abstract

The present invention discloses a method for remotely monitoring interlayer structural damage of wind turbine blades, comprising the following steps: firstly, marking multiple collection points on the wind turbine blades, and collecting the vibration frequency and acceleration in the X-axis, Y-axis and Z-axis directions of the collection points for monitoring; then, processing and transforming the multiple groups of vibration frequency values ​​and multiple groups of acceleration values ​​collected in S1 into instantaneous parameters; secondly, establishing an ARX model, converting the multiple groups of acceleration values ​​of the collection points on the wind turbine blades into standard acceleration parameters, and defining them as damage characteristic parameters; then, comparing the instantaneous parameters with the damage characteristic parameters of the wind turbine blades, and transmitting the comparison results to an external server for storage and publication. The method of the present invention has high sensitivity, can remotely monitor whether there is interlayer structural damage in the wind turbine blades, and specifically compares the calculated instantaneous parameters with the damage characteristic parameters of the wind turbine blades, with small errors, thus improving the accuracy of monitoring and being more adaptable.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine blade monitoring, and in particular to a method for remotely monitoring interlayer structural damage of a wind turbine blade. Background Art

[0002] The rotor blades of wind turbines rely on their special aerodynamic shape to capture wind energy and convert it into mechanical energy. As a component of wind turbines to capture wind energy, wind turbine blades play an extremely important role in wind turbines. Their roots are connected to the hub through bolts and are directly subjected to force on the unit. Therefore, as a directly stressed component, the damage condition of wind turbine blades after long-term stress plays a vital role in the efficiency and safety of wind turbines.

[0003] At present, the existing monitoring methods have certain errors, and it is difficult to quickly and effectively determine whether there is interlayer structural damage in the wind turbine blades, and to accurately determine the location and extent of the current interlayer structural damage. This is not conducive to subsequent maintenance, which is very unfavorable for ensuring the efficient and safe use of wind turbines. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and to propose a method for remotely monitoring the interlayer structural damage of wind turbine blades.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for remotely monitoring interlayer structural damage of a wind turbine blade comprises the following steps:

[0007] S1. Mark multiple collection points on the wind turbine blade, monitor the vibration frequency and acceleration in the X-axis, Y-axis and Z-axis directions at the multiple collection points, and then record the vibration frequency value and acceleration value of each collection point;

[0008] S2, filtering and denoising the multiple groups of vibration frequency values ​​and the multiple groups of acceleration values ​​collected in S1, and transforming and calculating the data after decomposition filtering and denoising into instantaneous parameters;

[0009] S3, establish an ARX model, convert multiple groups of acceleration values ​​of multiple collection points on the wind turbine blade into standard acceleration parameters, and define them as damage characteristic parameters;

[0010] S4. Compare the instantaneous parameters with the damage characteristic parameters of the wind turbine blades, and transmit the comparison results to an external server through a wireless transmission module for storage and publication.

[0011] Furthermore, in S2, the data values ​​after decomposition filtering and denoising are obtained to obtain two groups of residual signals, the two groups of residual signals are subjected to Hilbert transform to obtain two corresponding groups of analytical signals, and then the instantaneous parameters of the two groups of analytical signals are calculated.

[0012] Furthermore, in step S4, the designated collection point where interlayer structural damage occurs on the wind turbine blade is locked according to the comparison result, the moment when the interlayer structural damage occurs is recorded, and the degree of interlayer structural damage is determined according to the comparison result; the instantaneous parameters and the damage characteristic parameters of the wind turbine blade are recorded online, and statistical graphs of different time periods are established.

[0013] Furthermore, the specific steps for comparing the instantaneous parameters with the damage characteristic parameters of the wind turbine blade are as follows:

[0014] When the instantaneous parameter is greater than the damage characteristic parameter, it is determined that the current wind turbine blade has interlayer structural damage, and the comparison result is transmitted to the external server through the wireless transmission module and an alarm is issued;

[0015] When the instantaneous parameter is less than the damage characteristic parameter, it is determined that there is no interlayer structural damage in the current wind turbine blade, and only the comparison result is transmitted to the external server through the wireless transmission module, and no alarm is issued;

[0016] When the instantaneous parameter and the damage characteristic parameter are equal, steps S1 to S4 are repeated, and the instantaneous parameter and the damage characteristic parameter of the wind turbine blade are compared again;

[0017] When the instantaneous parameter is much larger than the damage characteristic parameter, for multiple sets of comparison results with such large differences, steps S1 to S4 should be repeated and the comparison results should be resent to eliminate the error.

[0018] Furthermore, the vibration waveforms of the wind turbine blades are obtained on the X, Y and Z axes of the collection points respectively, and the vibration waveforms of the three wind turbine blades at the same time are compared in the same statistical chart. When the similarity of the vibration waveforms of the three blades is lower than the standard threshold, it is determined that the wind turbine blade is damaged, otherwise there is no damage.

[0019] Furthermore, the degree of interlayer structure damage is divided into mild, moderate and severe, where a ratio of the instantaneous parameter to the damage characteristic parameter between 1-5 is judged as mild damage, a ratio of the instantaneous parameter to the damage characteristic parameter between 5-12 is judged as moderate damage, and a ratio of the instantaneous parameter to the damage characteristic parameter between 12-18 is judged as severe damage. The structural damage index within a single monitoring time period is calculated by combining the undamaged identification parameters calculated under normal operating conditions of the wind turbine blades with the actual values ​​of the instantaneous parameters.

[0020] Furthermore, the statistical graphs of different time periods are based on the wind turbine blade operating parameter information at the same time and in the same state, and the identifiable parameters under the current statistical graph are recorded, wherein the identifiable parameters include stiffness parameters and damping parameters.

[0021] Furthermore, the vibration frequency and acceleration monitoring method in the X, Y and Z axis directions at the collection point is: the vibration sensor and the acceleration sensor are respectively installed on the front side, the outer side and the inner side of the wind turbine blade, and the distances between the acceleration sensors are equal, wherein the Z axis is installed perpendicular to the wind turbine blade.

[0022] Furthermore, the acceleration monitoring time in the X, Y and Z axis directions is 5-10 minutes, and the vibration frequency monitoring time in the X, Y and Z axis directions is 12-20 minutes.

[0023] The present invention has the following advantages:

[0024] The method of the present invention has high sensitivity and can remotely monitor whether there is interlayer structural damage in the wind turbine blade. The calculated instantaneous parameters are specifically compared with the damage characteristic parameters of the wind turbine blade, with small errors, which improves the accuracy of monitoring and is more adaptable. It can quickly and accurately find the location where the interlayer structural damage occurs, which is beneficial for subsequent maintenance. In addition, the method greatly reduces the difficulty of identifying interlayer structural damage in actual engineering, improves the efficiency of identifying interlayer structural damage, and improves safety. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0026] Example 1

[0027] A method for remotely monitoring interlayer structural damage of a wind turbine blade comprises the following steps:

[0028] S1. Mark multiple collection points on the wind turbine blade, monitor the vibration frequency and acceleration in the X-axis, Y-axis and Z-axis directions at the multiple collection points, and then record the vibration frequency value and acceleration value of each collection point;

[0029] S2, filtering and denoising the multiple groups of vibration frequency values ​​and the multiple groups of acceleration values ​​collected in S1, and transforming and calculating the data after decomposition filtering and denoising into instantaneous parameters;

[0030] S3, establish an ARX model, convert multiple groups of acceleration values ​​of multiple collection points on the wind turbine blade into standard acceleration parameters, and define them as damage characteristic parameters;

[0031] S4. Compare the instantaneous parameters with the damage characteristic parameters of the wind turbine blades, and transmit the comparison results to an external server through a wireless transmission module for storage and publication.

[0032] The method for remotely monitoring interlayer structural damage of wind turbine blades of the present invention has high monitoring sensitivity, can remotely monitor whether there is interlayer structural damage in the wind turbine blades, and specifically compares the calculated instantaneous parameters with the damage characteristic parameters of the wind turbine blades, with small error, high accuracy, and greater adaptability.

[0033] Example 2

[0034] On the basis of Example 1: In S2, the data values ​​after filtering and denoising are decomposed to obtain two groups of residual signals, and the two groups of residual signals are subjected to Hilbert transform to obtain two corresponding groups of analytical signals, and then the instantaneous parameters under the current two groups of analytical signals are calculated; in step S4, according to the comparison result, the designated collection point where interlayer structural damage occurs on the wind turbine blade is locked, the moment when the interlayer structural damage currently occurs is recorded, and the degree of interlayer structural damage is determined according to the comparison result; the instantaneous parameters and the damage characteristic parameters of the wind turbine blade are recorded online, and statistical graphs of different time periods are established; the type of the statistical graph is any one of a fan-shaped statistical graph, a bar statistical graph and a line statistical graph. The specific comparison steps of the instantaneous parameter and the damage characteristic parameter of the wind turbine blade are as follows: when the instantaneous parameter is greater than the damage characteristic parameter, it is determined that the current wind turbine blade has interlayer structural damage, and the comparison result is transmitted to the external server through the wireless transmission module and an alarm is given; when the instantaneous parameter is less than the damage characteristic parameter, it is determined that the current wind turbine blade does not have interlayer structural damage, and only the comparison result is transmitted to the external server through the wireless transmission module, and no alarm is given; when the instantaneous parameter and the damage characteristic parameter are equal or when the instantaneous parameter is much greater than the damage characteristic parameter, the steps S1 to S4 are repeated, and the instantaneous parameter is compared with the damage characteristic parameter of the wind turbine blade again, and the error can be eliminated by repeated comparison. The method has high sensitivity, can remotely monitor whether there is interlayer structural damage in the wind turbine blade, and specifically compares the calculated instantaneous parameter with the damage characteristic parameter of the wind turbine blade, with small error, improved monitoring accuracy, and more adaptability.

[0035] Example 3

[0036] On the basis of Example 1 or Example 2: the vibration waveform of the wind turbine blade is obtained on the X, Y and Z axes of the collection point respectively, and the vibration waveforms of the three wind turbine blades at the same time are placed in the same statistical chart for comparison. When the similarity of the vibration waveforms of the three blades is lower than the standard threshold, it is determined that the wind turbine blade is damaged, otherwise there is no damage. The degree of interlayer structure damage is divided into mild, moderate and severe, wherein when the ratio of the instantaneous parameter to the damage characteristic parameter is between 1-5, it is determined as mild damage, when the ratio of the instantaneous parameter to the damage characteristic parameter is between 5-12, it is determined as moderate damage, and when the ratio of the instantaneous parameter to the damage characteristic parameter is between 12-18, it is determined as severe damage. The undamaged identification parameter calculated under the normal operation state of the wind turbine blade is combined with the actual value of the instantaneous parameter to calculate the structural damage index within a single monitoring time period. It can quickly and accurately find the location and degree of damage of the interlayer structure damage, which is conducive to subsequent maintenance. In addition, this method also greatly reduces the difficulty of interlayer structure damage identification in actual engineering and improves the efficiency of interlayer structure damage identification. Of course, the correspondence between the ratio of the instantaneous parameter to the damage characteristic parameter and the classification of the degree of interlayer structure damage can be set according to the specific situation of the wind turbine blade to solve the judgment of the degree of damage under the use status of a specific wind turbine blade, which is more conducive to the division and processing of maintenance levels. It can be adjusted according to the environment in which the wind turbine blade is used and the priority of the maintenance level, and reasonable graded maintenance can be carried out while ensuring safety to the greatest extent.

[0037] Preferably, the statistical graphs of different time periods are based on the wind turbine blade operating parameter information at the same time and in the same state, and the identifiable parameters under the current statistical graph are recorded, wherein the identifiable parameters include stiffness parameters and damping parameters. This is convenient for later data statistics and analysis to establish a more scientific and reasonable data model for technological innovation.

[0038] Preferably: the vibration frequency and acceleration monitoring method in the X, Y and Z axis directions at the collection point is: the vibration sensor and the acceleration sensor are respectively installed on the front side, the outer side and the inner side of the wind turbine blade, and the distances between the acceleration sensors are equal, wherein the Z axis is installed perpendicular to the wind turbine blade; the acceleration monitoring time in the X, Y and Z axis directions is 5-10 minutes, and the vibration frequency monitoring time in the X, Y and Z axis directions is 12-20 minutes.

[0039] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for remotely monitoring interlayer structural damage of wind turbine blades, characterized in that: The following steps are involved: S1. Mark multiple collection points on the wind turbine blade, monitor the vibration frequency and acceleration in the X-axis, Y-axis and Z-axis directions at the multiple collection points, and then record the vibration frequency value and acceleration value of each collection point; the vibration frequency and acceleration monitoring method in the X-axis, Y-axis and Z-axis directions at the collection points is: install the vibration sensor and the acceleration sensor on the front side, the outer side and the inner side of the wind turbine blade respectively, and the distance between the acceleration sensors is equal, wherein the Z axis is installed perpendicular to the wind turbine blade; S2, filtering and denoising the multiple groups of vibration frequency values ​​and the multiple groups of acceleration values ​​collected in S1, and transforming and calculating the data after decomposition filtering and denoising into instantaneous parameters; in the step S2, the data values ​​after decomposition filtering and denoising are obtained to obtain two groups of residual signals, and the two groups of residual signals are subjected to Hilbert transformation to obtain two corresponding groups of analytical signals, and then the instantaneous parameters under the current two groups of analytical signals are calculated; S3, establish an ARX model, convert multiple groups of acceleration values ​​of multiple collection points on the wind turbine blade into standard acceleration parameters, and define them as damage characteristic parameters; S4. Compare the instantaneous parameters with the damage characteristic parameters of the wind turbine blades, and transmit the comparison results to an external server through a wireless transmission module for storage and publication.

2. The method for remotely monitoring interlayer structural damage of a wind turbine blade according to claim 1, characterized in that: In step S4, according to the comparison result, the designated collection point where the interlayer structure damage occurs on the wind turbine blade is locked, the moment when the interlayer structure damage currently occurs is recorded, and the degree of the interlayer structure damage is determined according to the comparison result; The instantaneous parameters and damage characteristic parameters of the wind turbine blades are recorded online, and statistical graphs of different time periods are established.

3. The method for remotely monitoring interlayer structural damage of a wind turbine blade according to claim 1, characterized in that: The specific comparison and judgment method between the instantaneous parameters and the damage characteristic parameters of the wind turbine blades is as follows: When the instantaneous parameter is greater than the damage characteristic parameter, it is determined that the current wind turbine blade has interlayer structural damage, and the comparison result is transmitted to the external server through the wireless transmission module and an alarm is issued; When the instantaneous parameter is less than the damage characteristic parameter, it is determined that there is no interlayer structural damage in the current wind turbine blade, and only the comparison result is transmitted to the external server through the wireless transmission module, and no alarm is issued; When the instantaneous parameter and the damage characteristic parameter are equal, steps S1 to S4 are repeated, and the instantaneous parameter and the damage characteristic parameter of the wind turbine blade are compared again, and the error is eliminated by repeated comparison; When the instantaneous parameter is much larger than the damage characteristic parameter, for multiple sets of comparison results with such large differences, steps S1 to S4 should be repeated and the comparison results should be resent to eliminate the error.

4. The method for remotely monitoring interlayer structural damage of a wind turbine blade according to claim 1, characterized in that: The vibration waveforms of the wind turbine blades are obtained on the X, Y and Z axes of the collection points respectively, and the vibration waveforms of the three wind turbine blades at the same time are compared in the same statistical chart. When the similarity of the vibration waveforms of the three blades is lower than the standard threshold, it is determined that the wind turbine blade is damaged, otherwise there is no damage.

5. The method for remotely monitoring interlayer structural damage of a wind turbine blade according to claim 2, characterized in that: The type of the statistical chart is any one of a pie chart, a bar chart and a line chart.

6. The method for remotely monitoring interlayer structural damage of a wind turbine blade according to claim 2, characterized in that: The degree of interlayer structure damage is divided into mild, moderate and severe. When the ratio of the instantaneous parameter to the damage characteristic parameter is between 1-5, it is judged as mild damage, when the ratio of the instantaneous parameter to the damage characteristic parameter is between 5-12, it is judged as moderate damage, and when the ratio of the instantaneous parameter to the damage characteristic parameter is between 12-18, it is judged as severe damage. The structural damage index within a single monitoring time period is calculated by combining the undamaged identification parameters calculated under normal operating conditions of the wind turbine blades with the actual values ​​of the instantaneous parameters.

7. The method for remotely monitoring interlayer structural damage of a wind turbine blade according to claim 2, characterized in that: The statistical graphs of different time periods are based on the wind turbine blade operating parameter information at the same time and in the same state, and record the identifiable parameters under the current statistical graph, wherein the identifiable parameters include stiffness parameters and damping parameters.

8. The method for remotely monitoring interlayer structural damage of a wind turbine blade according to claim 1, characterized in that: The acceleration monitoring time in the X, Y and Z axis directions is 5-10 minutes, and the vibration frequency monitoring time in the X, Y and Z axis directions is 12-20 minutes.