Blade surface stress monitoring system and working method

Abstract

The present invention discloses a blade surface stress monitoring system and working method, wherein the monitoring system comprises a deformation signal acquisition module, a wireless transmission module, a wind measurement module and a data analysis module, wherein the deformation signal acquisition module and the wind measurement module are respectively connected to the wireless transmission module, and the wireless transmission module is connected to the data analysis module. The present invention realizes the integration of monitoring and discrimination, and by establishing an alarm value function f1 of abnormal deformation under different wind speeds and an alarm function f2 of the difference value between different blade deformations under the same wind speed, a longitudinal comparison between the blade operation state under different wind speeds and its standard normal operation state, and a lateral comparison between different blade deformations under the same wind speed are performed, which can effectively avoid false alarms caused by changes in other external factors or failure of a temperature compensator, improve the accuracy and early warning capability of monitoring, predict the possible failure forms of blades in advance, and avoid safety accidents and economic losses.

Description

Technical Field

[0001] The present invention relates to the technical field of fan operation status monitoring, and in particular to a blade surface stress monitoring system and a working method. Background Art

[0002] In recent years, the wind power industry has developed rapidly, and the rapid increase in wind power installed capacity has also brought about more and more safety incidents caused by blade damage. How to accurately monitor the operating status of the blades, and then detect problems in advance in the early stage of blade failure to avoid greater losses has also become a hot issue in the industry. At present, relevant patents have proposed blade status monitoring technologies such as monitoring blade stress through optical glass fiber and judging blade crack status through image recognition. However, most of these technologies focus on equipment optimization and measurement point layout, and there are few improvements in the judgment technology of whether the blade operating status is normal or not. In particular, there is still a lack of a systematic blade surface stress detection system that integrates advanced detection equipment and flexible and accurate judgment methods. In addition, the existing technology is affected by external factors, such as temperature and humidity changes, or false alarms caused by failure of the temperature compensator. Therefore, there is an urgent need for a monitoring system that improves monitoring accuracy and early warning capabilities. Summary of the invention

[0003] The purpose of the present invention is to address the problems in the above-mentioned prior art and provide a blade surface stress monitoring system and working method, which improves the accuracy and advancement of wind turbine operating status monitoring, realizes advanced detection and identification integration, and can be systematically applied to operating and newly built wind turbines.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme:

[0005] A blade surface stress monitoring system comprises a deformation signal acquisition module, a wireless transmission module, a wind measurement module and a data analysis module, wherein the deformation signal acquisition module and the wind measurement module are respectively connected to the wireless transmission module, and the wireless transmission module is connected to the data analysis module;

[0006] The deformation signal acquisition module is used to acquire blade deformation signals;

[0007] The wind measurement module is used to measure and obtain wind speed signals;

[0008] The data analysis module is used to receive blade deformation signals and wind speed signal data, and compare the blade deformation signal data with the blade deformation threshold corresponding to the wind speed signal data; when the blade deformation signal data exceeds the blade deformation threshold corresponding to the wind speed signal data, a monitoring warning signal is output.

[0009] Furthermore, the blade deformation threshold corresponding to the wind speed signal data is obtained by analyzing and fitting the blade deformation signal and wind speed signal data through a data analysis module, and establishing an alarm function.

[0010] Furthermore, the monitoring system also includes a temperature compensation module, which is installed on the blade and is used to compensate for the stress changes on the blade surface caused by temperature changes.

[0011] Furthermore, the deformation signal acquisition module and the temperature compensation module are installed on the back curved surface of the blade.

[0012] Furthermore, the deformation signal acquisition module and the temperature compensation module are embedded in the back arc surface of the blade in a newly built unit.

[0013] Furthermore, the deformation signal acquisition module and the temperature compensation module are arranged in a manner that the fiberglass epoxy resin is pasted into the back arc of the blade in the operating unit.

[0014] Furthermore, the deformation signal acquisition module is a fiber grating deformation sensor.

[0015] Furthermore, the wind measurement module adopts a cabin anemometer, a wind tower or a laser radar.

[0016] As another object of the present invention, the present invention provides a working method of a blade surface stress monitoring system, comprising the following steps:

[0017] S1, collecting blade deformation signals and wind speed at different times;

[0018] S2, converting the deformation signal collected in step S1 into a blade deformation model;

[0019] S3, establishing a correspondence between the blade deformation model at different times and the wind speed at the corresponding time, and using a big data analysis algorithm to obtain the corresponding relationship between the wind speed and the deformation;

[0020] S4, establishing an alarm value function f1 of abnormal deformation under different wind speeds through the corresponding relationship obtained in step S3;

[0021] S5, establishing a horizontal comparison rule for different blade deformations, analyzing the difference relationship between different blade deformations under the same wind speed, and setting a difference value alarm function f2;

[0022] S6. Analyze whether the measured blade deformation exceeds the threshold value corresponding to the alarm value function f1 under the corresponding wind speed or whether the difference value of different blade deformations exceeds the threshold value corresponding to the difference value alarm function f2. If the blade deformation exceeds the threshold value corresponding to the alarm value function f1 under the corresponding wind speed or the difference value of different blade deformations exceeds the threshold value corresponding to the difference value alarm function f2, provide an early warning to the operation monitoring personnel and equipment fault diagnosis personnel.

[0023] Furthermore, in step S1, the deformation signal of the blade is collected inside or on the surface of the blade.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention discloses a blade surface stress monitoring system, which realizes advanced detection and discrimination integration by connecting the deformation signal acquisition module and the wind measurement module to the wireless transmission module respectively, and connecting the wireless transmission module to the data analysis module, and can be systematically applied to the wind turbines in operation and newly built. The system has a simple structure, low cost and is easy to implement.

[0026] Furthermore, a temperature compensation module is provided to compensate for stress changes caused by temperature changes, thereby preventing the monitoring results from being affected by temperature and causing large errors.

[0027] Furthermore, the deformation signal acquisition module and the temperature compensation module are embedded in the back arc surface of the blade in the newly built unit, which can improve the sensitivity of monitoring potential defects in the blade.

[0028] Furthermore, the deformation signal acquisition module and the temperature compensation module are set up in the operating unit by using fiberglass epoxy resin to stick into the back arc of the blade, which can reduce the pressure effect of the incoming wind and improve the accuracy of monitoring.

[0029] The present invention discloses a working method of a blade surface stress monitoring system. The method establishes an alarm value function f1 of abnormal deformation at different wind speeds and a difference value alarm function f2 between different blade deformations at the same wind speed, and performs a longitudinal comparison between the blade operating state at different wind speeds and its standard normal operating state, as well as a lateral comparison between different blade deformations at the same wind speed. The method can effectively avoid false alarms caused by changes in other external factors (temperature, humidity, etc.) or failure of a temperature compensator, improve the monitoring accuracy and early warning capability, predict possible failure forms of the blade in advance, and avoid safety accidents and economic losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a monitoring flow chart of the blade surface stress monitoring system of the present invention;

[0031] Figure 2The schematic block diagram of the blade surface stress monitoring system for the operating unit is shown in FIG.

[0032] Figure 3 This is a schematic block diagram of the blade surface stress monitoring system for a newly built unit. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, the contents of which are intended to explain the present invention rather than to limit it:

[0034] like Figure 1 , a blade surface stress monitoring system of the present invention comprises a deformation signal acquisition module, a wireless transmission module, a wind measurement module and a data analysis module, wherein the deformation signal acquisition module and the wind measurement module are respectively connected to the wireless transmission module, and the wireless transmission module is connected to the data analysis module;

[0035] The deformation signal acquisition module is used to acquire blade deformation signals;

[0036] The wind measurement module is used to measure and obtain wind speed signals, and the wind measurement module adopts a cabin anemometer, a wind tower or a laser radar.

[0037] The data analysis module is used to receive blade deformation signals and wind speed signal data, and compare the blade deformation signal data with the blade deformation threshold corresponding to the wind speed signal data; when the blade deformation signal data exceeds the blade deformation threshold corresponding to the wind speed signal data, a monitoring warning signal is output. The system realizes the integration of detection and discrimination, and can be systematically applied to in-service and newly built wind turbines. The system has a simple structure, low cost, and is easy to implement.

[0038] In one embodiment of the present invention, the blade deformation threshold corresponding to the wind speed signal data is obtained by analyzing and fitting the blade deformation signal and wind speed signal data through a data analysis module to establish an alarm function.

[0039] In one embodiment of the present invention, the blade surface stress monitoring system further includes a temperature compensation module, which is installed on the blade and is used to compensate for blade surface stress changes caused by temperature changes, thereby preventing the monitoring results from being affected by temperature and causing large errors.

[0040] In one embodiment of the present invention, the deformation signal acquisition module and the temperature compensation module are installed on the back curved surface of the blade.

[0041] In one embodiment of the present invention, in a newly built unit, such as Figure 3 As shown, the deformation signal acquisition module and the temperature compensation module are embedded in the back arc surface of the blade, which can improve the sensitivity of monitoring potential defects in the blade; preferably, the deformation signal acquisition module adopts a fiber grating deformation sensor.

[0042] In one embodiment of the present invention, in an operating unit, such as Figure 2 As shown, the deformation signal acquisition module and the temperature compensation module are set up by glass fiber reinforced plastic epoxy resin pasted into the back arc of the blade, which can reduce the pressure impact of the incoming wind and improve the accuracy of monitoring. Preferably, the deformation signal acquisition module uses a fiber grating deformation sensor.

[0043] A working method of a blade surface stress monitoring system comprises the following steps:

[0044] S1, collecting blade deformation signals and wind speed at different times;

[0045] S2, converting the deformation signal collected in step S1 into a blade deformation model;

[0046] S3, establishing a correspondence between the blade deformation model at different times and the wind speed at the corresponding time, and using a big data analysis algorithm to obtain the corresponding relationship between the wind speed and the deformation;

[0047] S4, establishing an alarm value function f1 of abnormal deformation under different wind speeds through the corresponding relationship obtained in step S3;

[0048] S5, establishing a horizontal comparison rule for different blade deformations, analyzing the difference relationship between different blade deformations under the same wind speed, and setting a difference value alarm function f2;

[0049] S6. Analyze whether the measured blade deformation exceeds the threshold value corresponding to the alarm value function f1 under the corresponding wind speed or whether the difference value of different blade deformations exceeds the threshold value corresponding to the difference value alarm function f2. If the blade deformation exceeds the threshold value corresponding to the alarm value function f1 under the corresponding wind speed or the difference value of different blade deformations exceeds the threshold value corresponding to the difference value alarm function f2, provide an early warning to the operation monitoring personnel and equipment fault diagnosis personnel.

[0050] Preferably, in step S1, the deformation signal of the blade is collected inside or on the surface of the blade.

[0051] When the working method of the monitoring system of the present invention is applied to multiple wind turbines in a wind farm, wind turbines of the same model can share the corresponding relationship obtained in step S3 and the alarm value function f1 and difference value alarm function f2 obtained in steps S4 and S5.

[0052] The working method of the monitoring system of the present invention establishes an alarm value function f1 for abnormal deformation at different wind speeds and an alarm function f2 for the difference value between different blade deformations at the same wind speed, and performs a longitudinal comparison between the blade operating status at different wind speeds and its standard normal operating status, as well as a lateral comparison of different blade deformations at the same wind speed. This can effectively avoid false alarms caused by changes in other external factors (temperature, humidity, etc.) or failure of the temperature compensator, improve the accuracy and early warning capabilities of monitoring, predict possible failure modes of blades in advance, and avoid safety accidents and economic losses.

[0053] However, the example embodiments can be implemented in various forms and should not be construed as being limited to the embodiments described herein; a person of ordinary skill in the art, inspired by the present invention, can make many forms without departing from the spirit of the present invention and the scope of protection of the claims, all of which fall within the scope of protection of the present invention.

Claims

1. A working method of a blade surface stress monitoring system, the blade surface stress monitoring system comprising a deformation signal acquisition module, a wireless transmission module, a wind measurement module and a data analysis module, the deformation signal acquisition module and the wind measurement module are respectively connected to the wireless transmission module, and the wireless transmission module is connected to the data analysis module; the deformation signal acquisition module is used to collect blade deformation signals; the wind measurement module is used to measure and obtain wind speed signals; the data analysis module is used to receive blade deformation signal data and wind speed signal data, and compare the blade deformation signal data with the blade deformation threshold value corresponding to the wind speed signal data; When the blade deformation signal data exceeds the blade deformation threshold corresponding to the wind speed signal data, a monitoring warning signal is output; The blade deformation threshold corresponding to the wind speed signal data is obtained by analyzing and fitting the blade deformation signal and wind speed signal data through a data analysis module, and establishing an alarm function; the blade surface stress monitoring system also includes a temperature compensation module, which is installed on the blade to compensate for the blade surface stress changes caused by temperature changes; it is characterized in that it includes the following steps: S1, collecting blade deformation signals and wind speed at different times; S2, converting the deformation signal collected in step S1 into a blade deformation model; S3, establishing a correspondence between the blade deformation model at different times and the wind speed at the corresponding time, and using a big data analysis algorithm to obtain the corresponding relationship between the wind speed and the deformation; S4, establishing an alarm value function f1 of abnormal deformation under different wind speeds through the corresponding relationship obtained in step S3; S5, establishing a horizontal comparison rule for different blade deformations, analyzing the difference relationship between different blade deformations under the same wind speed, and setting a difference value alarm function f2; S6. Analyze whether the measured blade deformation exceeds the threshold value corresponding to the alarm value function f1 under the corresponding wind speed or whether the difference value of different blade deformations exceeds the threshold value corresponding to the difference value alarm function f2. If the blade deformation exceeds the threshold value corresponding to the alarm value function f1 under the corresponding wind speed or the difference value of different blade deformations exceeds the threshold value corresponding to the difference value alarm function f2, provide an early warning to the operation monitoring personnel and equipment fault diagnosis personnel.

2. The working method of the blade surface stress monitoring system according to claim 1, characterized in that: In step S1, the deformation signal of the blade is collected inside or on the surface of the blade.

3. The working method of the blade surface stress monitoring system according to claim 1, characterized in that: The deformation signal acquisition module and the temperature compensation module of the blade surface stress monitoring system are installed on the back curved surface of the blade.

4. The working method of the blade surface stress monitoring system according to claim 1, characterized in that: The deformation signal acquisition module and the temperature compensation module of the blade surface stress monitoring system are embedded in the back arc surface of the blade in a newly built unit.

5. The working method of the blade surface stress monitoring system according to claim 1, characterized in that: The deformation signal acquisition module and the temperature compensation module of the blade surface stress monitoring system are arranged in a manner that the fiberglass epoxy resin is pasted into the back arc of the blade in the operating unit.

6. The working method of the blade surface stress monitoring system according to claim 1, characterized in that: The deformation signal acquisition module of the blade surface stress monitoring system is a fiber grating deformation sensor.

7. The working method of the blade surface stress monitoring system according to claim 1, characterized in that: The wind measurement module of the blade surface stress monitoring system adopts a wind measurement tower or a laser radar.

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