A wind tower flange joint surface crack monitoring and early warning method and system

Abstract

The present invention discloses a method and system for monitoring and warning cracks on the flange joint surface of a wind turbine tower, which relates to the technical field of wind turbine towers. The deployment module deploys several groups of sensors around the flange joint surface of the connecting tower section of the wind turbine tower, further realizing real-time monitoring and data collection of bolt preload, crack state and load-bearing degree; the data monitoring module can record and upload these data in real time, ensuring multi-faceted monitoring of the operating status of the wind turbine tower, and further improving the timeliness and accuracy of monitoring. Through the bolt force distribution module, the system can calculate the average difference value Yscz of the preload force based on the processed preload force distribution difference data information. If the average difference value Yscz of the preload force exceeds the set difference threshold value L, the system will issue a preliminary warning instruction to promptly remind maintenance personnel to conduct inspections and maintenance, and further avoid structural damage and safety hazards caused by uneven preload force.

Description

Technical Field

[0001] The invention relates to the technical field of wind power towers, and in particular to a method and system for monitoring and early warning cracks on a flange joint surface of a wind power tower. Background Art

[0002] With the rapid development of renewable energy, wind power generation has been widely used as a clean energy. As the supporting structure of the wind power generation system, the structural stability and safety of the wind tower are crucial to the operation of the entire wind power generation system. Among them, the flange joint surface of the wind tower is the key part of the connection between the tower sections, and it bears huge axial force, shear force and bending moment. Wind load, equipment weight and operating vibration are transmitted through the flange joint surface. If these loads cannot be effectively transmitted, it may cause local stress concentration, cause structural damage, and then affect the overall structural stability of the wind turbine.

[0003] In the field of flange joints of wind turbine towers, especially the study of the impact of joint crack prediction on the structural stability of wind turbines, it is of great significance for the safe operation and life extension of wind turbine towers. The current monitoring and maintenance of flange joints of wind turbine towers mainly rely on manual inspection and regular maintenance, which has certain limitations and shortcomings. First of all, manual inspection is difficult to achieve real-time monitoring, and it is easy to ignore potential structural problems, resulting in the failure to timely discover and deal with cracks on the flange joint surface in the early stages. In addition, the existing monitoring systems often fail to fully consider multiple parameters such as preload distribution, crack state, number of stress cycles, and wind loads, lack systematic evaluation and prediction capabilities, and are difficult to provide accurate early warning information. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method and system for monitoring and early warning cracks on the flange joint surface of a wind turbine tower, which solves the problems in the above-mentioned background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a wind tower flange joint surface crack monitoring and early warning system, including a deployment module, a data monitoring module, a data processing module, a bolt force distribution module, a joint surface state prediction module and an early warning management module;

[0006] The deployment module is used to deploy several groups of sensors around the flange joint surfaces of the wind tower connecting the tower sections in advance, collect relevant data information obtained by the several groups of sensors, and upload the relevant data information to the cloud server;

[0007] The data monitoring module is used to monitor the preload distribution difference data information applied to the bolts in the flange joint surface of the wind tower in real time, and to record the existing crack status information in the flange joint surface in real time. At the same time, during the operation of the wind turbine generator at the top of the wind tower, the relevant load-bearing degree data information of the flange joint surface connecting the tower sections is monitored and recorded;

[0008] The data processing module is used to perform data preprocessing on the preload force distribution difference data information, the existing crack state information and the related load-bearing degree data information, and summarize and generate a combination surface state set;

[0009] The bolt force distribution module is used to calculate and obtain the average difference value Yscz of the preload force based on the processed preload force distribution difference data information applied to the bolt, and if the average difference value Yscz of the preload force exceeds the difference threshold value L, a preliminary warning instruction is issued externally;

[0010] The joint surface state prediction module is used to extract features from the processed joint surface state set after receiving the preliminary warning instruction, so as to obtain the crack depth Lwsd, the crack density Lwmd, the stress cycle number Yxcs and the wind load difference Fzcz respectively, and calculate the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs of the flange joint surface through the trained joint surface crack prediction model, and fit and analyze the structural stability assessment index Jpzs of the wind turbine by correlating the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs;

[0011] The early warning management module is used to pre-set an evaluation threshold W, and compare and analyze the evaluation threshold W with the structural stability evaluation index Jpzs to comprehensively judge the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine, and take corresponding early warning protection measures.

[0012] Preferably, the deployment module includes a sensor building unit and a transmission unit;

[0013] The sensor construction unit is used to deploy several groups of sensors around the flange joint surface of the wind tower connecting the tower sections, wherein the several groups of sensors include strain sensors, load sensors, vibration sensors, temperature sensors, crack monitoring instruments, metal fatigue testing machines and wind speed sensors;

[0014] The transmission unit is used to transmit relevant data information obtained by several groups of sensors to a cloud server via a wireless network to support remote monitoring and maintenance, and temporarily store the relevant data information obtained by several groups of sensors when communication transmission is interrupted. At the same time, an edge computing function is integrated in the transmission unit to perform preliminary processing on the relevant data information obtained by several groups of sensors.

[0015] Preferably, the data monitoring module includes a preliminary monitoring unit, an existing damage monitoring unit and a bearing capacity monitoring unit;

[0016] The preliminary monitoring unit is used to monitor and record in real time the pre-tightening force distribution difference data information applied to the bolts in the flange joint surface of the wind tower, wherein the pre-tightening force distribution difference data information applied to the bolts includes the pre-tightening force values ​​Ys applied to a plurality of groups of bolts in the flange joint surface of the wind tower, and extracts the maximum value of the pre-tightening force value Ys therefrom;

[0017] The existing damage monitoring unit is used to record the existing crack state information in the flange joint surface in real time, wherein the existing crack state information includes the crack width Lsc, crack density Lwmd and crack depth Lwsd in the current flange joint surface;

[0018] The bearing capacity monitoring unit is used to monitor and record relevant bearing degree data information of the flange joint surface connecting the tower sections, wherein the relevant bearing degree data information includes the number of stress cycles Yxcs and fatigue strength Qqd of the flange joint surface under cyclic load, and the wind load borne by the wind turbine at the top of the wind tower. The wind load difference Fzcz is obtained based on the wind load monitored during the monitoring period.

[0019] Preferably, the bolt force distribution module includes a preliminary analysis unit and a preliminary warning unit;

[0020] The preliminary analysis unit is used to extract and obtain the preload force distribution difference data information applied to the bolt, and calculate and obtain the preload force average difference value Yscz.

[0021] Preferably, the preliminary warning unit is used to pre-set a difference threshold L, and compare and analyze the preload force average difference value Yscz with the difference threshold L to determine whether the tightening state in the flange joint surface of the current connection tower section is normal. The specific contents are as follows:

[0022] If the preload force mean difference value Yscz exceeds the difference threshold value L, it means that the tightening state in the flange joint surface of the current connecting tower section is not normal, and a preliminary warning instruction will be issued to the outside for further analysis;

[0023] If the preload force average difference value Yscz does not exceed the difference threshold value L, it indicates that the tightening state in the flange joint surface between the current connecting tower sections is normal.

[0024] Preferably, the bonding surface state prediction module includes an external analysis unit, an internal analysis unit and a comprehensive analysis unit;

[0025] The external analysis unit is used to perform linear normalization processing on the crack depth Lwsd and the crack density Lwmd according to the existing crack state information, and map the corresponding data values ​​within the interval [0, 1], and then obtain the crack presentation coefficient Lcxs.

[0026] Preferably, the internal analysis unit is used to obtain the joint surface load bearing coefficient Ccxs by correlating the stress cycle number Yxcs and the wind load difference Fzcz according to the relevant load-bearing degree data information and performing linear normalization processing.

[0027] Preferably, the comprehensive analysis unit is used to fit and analyze the structural stability assessment index Jpzs of the wind turbine generator by correlating the crack presentation coefficient Lcxs and the bonding surface load bearing coefficient Ccxs according to the bonding surface state set.

[0028] Preferably, the early warning management module includes an evaluation unit and a management unit;

[0029] The evaluation unit is used to compare and analyze the structural stability evaluation index Jpzs with the evaluation threshold W to comprehensively judge the influence of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine. The specific contents are as follows:

[0030] If the structural stability assessment index Jpzs> the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in an abnormal state, and a continuous red warning is issued;

[0031] If the structural stability assessment index Jpzs = the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in an abnormal state, and a continuous yellow warning is issued;

[0032] If the structural stability assessment index Jpzs is less than the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in a normal state, and three flashing green warnings are issued;

[0033] The management unit is used to take corresponding early warning protection measures according to the corresponding early warning results obtained in the evaluation unit, and the specific contents are as follows:

[0034] If a continuous red warning is issued, the wind turbine will be shut down immediately and professional technicians will be arranged to conduct further inspections, including inspections of the flange joint surface and the bolt connections inside the flange. According to the inspection results, necessary repairs and maintenance work will be carried out to repair the cracked flange joint surface, replace damaged bolts, and adjust the pre-tensioning force applied to the bolts in each bolt hole to keep it within a fixed range. After the repairs, the structural stability assessment will be carried out again;

[0035] If a continuous yellow warning is issued, while the wind turbine is in operation, a time period is limited and professional technicians are arranged on-site to monitor the joint surface of the wind tower and flange and tighten the bolts during this time period. At the same time, the wind speed changes around the wind tower are monitored in the background, the frequency of data collection and inspection is increased, and close attention is paid to structural changes;

[0036] If three flashing green warnings are issued, regular inspections and maintenance will continue according to the normal maintenance plan.

[0037] A method for monitoring and early warning cracks on a flange joint surface of a wind power tower comprises the following steps:

[0038] Step 1: First, deploy several groups of sensors around the flange joint surface of the wind tower connecting the tower sections, collect relevant data information obtained by the several groups of sensors, and upload the relevant data information to the cloud server;

[0039] Step 2: monitor the distribution difference data of the preload force applied to the bolts in the flange joint surface of the wind tower in real time, and record the existing crack status information in the flange joint surface in real time. At the same time, during the operation of the wind turbine at the top of the wind tower, monitor and record the relevant load-bearing data of the flange joint surface connecting the tower sections;

[0040] Step 3: Then pre-process the preload force distribution difference data information, the existing crack state information and the related load-bearing degree data information, and summarize and generate a combination surface state set;

[0041] Step 4: Based on the processed preload force distribution difference data information applied to the bolt, calculate and obtain the preload force average difference value Yscz. If the preload force average difference value Yscz exceeds the difference threshold value L, issue a preliminary warning instruction externally;

[0042] Step 5. After receiving the preliminary warning instruction, the processed joint surface state set is subjected to feature extraction to obtain the crack depth Lwsd, crack density Lwmd, stress cycle number Yxcs and wind load difference Fzcz respectively, and the crack presentation coefficient Lcxs and joint surface load bearing coefficient Ccxs of the flange joint surface are calculated through the trained joint surface crack prediction model. By correlating the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs, the structural stability assessment index Jpzs of the wind turbine is fitted and analyzed;

[0043] Step 6: pre-set an assessment threshold W, and compare and analyze the assessment threshold W with the structural stability assessment index Jpzs to comprehensively judge the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine, and take corresponding early warning protection measures.

[0044] The present invention provides a method and system for monitoring and early warning cracks on the flange joint surface of a wind turbine tower, which has the following beneficial effects:

[0045] (1) The deployment module deploys several groups of sensors around the flange joint surface of the wind tower connecting the tower sections, further realizing real-time monitoring and data collection of bolt preload, crack status and load level; the data monitoring module can record and upload these data in real time to ensure multi-faceted monitoring of the wind tower operation status, further improving the timeliness and accuracy of monitoring. Through the bolt force distribution module, the system can calculate the mean difference value Yscz of the preload force based on the processed preload force distribution difference data information. If the mean difference value Yscz of the preload force exceeds the set difference threshold L, the system will issue a preliminary warning instruction to promptly remind maintenance personnel to conduct inspections and maintenance, further avoiding structural damage and safety hazards caused by uneven preload; after receiving the preliminary warning instruction, the joint surface state prediction module further extracts features from the joint surface state set. Through the trained joint surface crack prediction model, the system can calculate the crack presentation coefficient Lcxs and joint surface load bearing coefficient Ccxs of the flange joint surface, and fit and analyze the structural stability assessment index Jpzs of the wind turbine, thereby providing a more comprehensive and accurate risk assessment. The early warning management module sets the evaluation threshold W and compares it with the structural stability evaluation index Jpzs to comprehensively judge the impact of the cracking risk of the wind tower flange joint surface on the structural stability of the wind turbine. According to the early warning results, the system takes corresponding early warning protection measures, such as continuous red warning, continuous yellow warning and three flashing yellow warnings, to further ensure timely and accurate response to situations at different risk levels and improve the safety and operational reliability of wind turbines. In short, the system can automatically collect, process and analyze data, reduce dependence on manual inspections, and further reduce the limitations and omission risks of manual inspections. Through intelligent early warning management, the efficiency and accuracy of maintenance work can be improved, the structural stability of the flange joint surface can be ensured, the service life of the wind tower can be extended, and the safe operation of wind turbines can be guaranteed.

[0046] (2) By timely identifying the uneven distribution of preload force, local stress concentration and potential structural damage caused by uneven preload force can be effectively prevented. The preliminary warning unit pre-sets the difference threshold L, and compares and analyzes the average difference value Yscz of the preload force with the difference threshold L, so as to judge the tightening state of the flange joint surface in real time, avoid structural failures caused by abnormal tightening state, and improve the reliability and safety of wind tower operation. Through the automated early warning mechanism, the system can continuously monitor and analyze the tightening state of the flange joint surface, reduce reliance on manual inspection, and improve monitoring efficiency and accuracy. Automated early warning not only saves human resources, but also can continuously provide real-time monitoring data during the operation of the wind tower, providing maintenance personnel with a reliable basis for decision-making.

[0047] (3) The comprehensive analysis unit combines the results of the external analysis unit and the internal analysis unit, comprehensively analyzes the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs, and calculates the structural stability assessment index Jpzs of the wind turbine. Through this comprehensive analysis method, the system can comprehensively evaluate the structural health status of the flange joint surface of the wind turbine tower, further predict potential cracking risks, provide accurate early warning information, and ensure the safe operation of the wind turbine tower. Through precise crack state analysis and comprehensive load-bearing capacity assessment, the system can provide more accurate early warning information. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A schematic diagram of the process of a wind tower flange joint surface crack monitoring and early warning system according to the present invention;

[0049] Figure 2 The present invention is a schematic diagram of the steps of a method for monitoring and early warning cracks on a flange joint surface of a wind power tower. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Example 1

[0052] See also Figure 1 , the present invention provides a wind tower flange joint surface crack monitoring and early warning system, including a deployment module, a data monitoring module, a data processing module, a bolt force distribution module, a joint surface state prediction module and an early warning management module;

[0053] The deployment module is used to deploy several groups of sensors around the flange joint surfaces of the wind tower connecting the tower sections in advance, collect relevant data information obtained by the several groups of sensors, and upload the relevant data information to the cloud server;

[0054] The data monitoring module is used to monitor the preload distribution difference data information applied to the bolts in the flange joint surface of the wind tower in real time, and to record the existing crack status information in the flange joint surface in real time. At the same time, during the operation of the wind turbine generator at the top of the wind tower, the relevant load-bearing degree data information of the flange joint surface connecting the tower sections is monitored and recorded;

[0055] The data processing module is used to perform data preprocessing on the preload force distribution difference data information, the existing crack state information and the related load-bearing degree data information, and summarize and generate a combination surface state set;

[0056] The bolt force distribution module is used to calculate and obtain the average difference value Yscz of the preload force based on the processed preload force distribution difference data information applied to the bolt, and if the average difference value Yscz of the preload force exceeds the difference threshold value L, a preliminary warning instruction is issued externally;

[0057] The joint surface state prediction module is used to extract features from the processed joint surface state set after receiving the preliminary warning instruction, so as to obtain the crack depth Lwsd, the crack density Lwmd, the stress cycle number Yxcs and the wind load difference Fzcz respectively, and calculate the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs of the flange joint surface through the trained joint surface crack prediction model, and fit and analyze the structural stability assessment index Jpzs of the wind turbine by correlating the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs;

[0058] The early warning management module is used to pre-set an evaluation threshold W, and compare and analyze the evaluation threshold W with the structural stability evaluation index Jpzs to comprehensively judge the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine, and take corresponding early warning protection measures.

[0059] During the operation of this system, the deployment module deploys several groups of sensors around the flange joint surface of the connecting tower section of the wind turbine tower to collect relevant data information in real time, including preload distribution difference, crack state and load degree data, and upload these data to the cloud server. Through real-time monitoring, the system can timely capture the dynamic changes of the flange joint surface, further avoiding the lag and limitations of traditional manual inspection. The data processing module pre-processes the collected preload distribution difference data information, crack state information and related load degree data information to generate a joint surface state set. This module further ensures the accuracy and integrity of the data and provides a reliable basis for subsequent analysis and prediction. The bolt force distribution module calculates the preload mean difference value Yscz based on the processed preload distribution difference data information. If the preload mean difference value Yscz exceeds the set difference threshold L, the system will issue a preliminary warning instruction to prompt the maintenance personnel to check and adjust the bolt preload in time to prevent stress concentration and structural damage caused by uneven preload; after receiving the preliminary warning instruction, the joint surface state prediction module extracts features from the joint surface state set to obtain a variety of key parameters. Through the trained joint surface crack prediction model, the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs are calculated, and the structural stability evaluation index Jpzs is fitted and analyzed. This prediction method further improves the prediction accuracy and reliability of the flange joint surface crack risk. The early warning management module comprehensively judges the impact of the flange joint surface crack risk on the structural stability of the wind turbine generator based on the comparative analysis of the evaluation threshold W and the structural stability evaluation index Jpzs, and takes corresponding early warning protection measures. Through the collaborative work of the above modules, this system can monitor the state of the flange joint surface in real time, warn of potential risks in advance, and provide scientific maintenance suggestions, which significantly improves the operational reliability and safety of the wind tower, extends its service life, and reduces maintenance costs and failure rates. In summary, the wind tower flange joint surface crack monitoring and early warning system of the present invention realizes comprehensive monitoring and early warning of the flange joint surface through advanced sensing technology, data processing and intelligent analysis, solves the limitations of traditional methods, and provides a more reliable and efficient wind tower structural stability guarantee solution.

[0060] Example 2

[0061] Please refer to Figure 1 ,Specifically: the deployment module includes a sensor building unit and a transmission unit;

[0062] The sensor construction unit is used to deploy several groups of sensors around the flange joint surface of the wind tower connecting the tower sections, wherein the several groups of sensors include strain sensors, load sensors, vibration sensors, temperature sensors, crack monitoring instruments, metal fatigue testing machines and wind speed sensors;

[0063] The transmission unit is used to transmit relevant data information obtained by several groups of sensors to a cloud server via a wireless network to support remote monitoring and maintenance, facilitate the management of wind towers in remote areas, protect the security of data transmission and storage, prevent data leakage and malicious attacks, and temporarily store relevant data information obtained by several groups of sensors when communication transmission is interrupted to ensure that data is not lost. At the same time, edge computing functions are integrated in the transmission unit to perform preliminary processing and analysis on the relevant data information obtained by several groups of sensors, thereby reducing data transmission volume and delay.

[0064] In this embodiment, by deploying several groups of sensors around the flange joint surface of the connecting tower section of the wind tower, it is possible to further accurately monitor the key parameters such as stress, load, vibration and temperature of the flange joint surface, ensure that the working status of the flange joint surface is captured in multiple aspects, and improve the accuracy and reliability of monitoring. The transmission unit transmits the relevant data information obtained by the sensor to the cloud server through a wireless network, supports remote monitoring and maintenance, and is particularly suitable for wind tower management in remote areas. Through remote monitoring, maintenance personnel can understand the operating status of the wind tower in a timely manner, reduce the frequency and cost of on-site inspections, and improve maintenance efficiency. When the communication transmission is interrupted, the transmission unit can temporarily store the relevant data information obtained by the sensor to ensure that the data is not lost. At the same time, the system uses encryption technology in the process of data transmission and storage to protect data security, prevent data leakage and malicious attacks, and enhance the reliability and security of the system.

[0065] Example 3

[0066] Please refer to Figure 1 ,Specifically: the data monitoring module includes a preliminary monitoring unit, an existing damage monitoring unit and a bearing capacity monitoring unit;

[0067] The preliminary monitoring unit is used to monitor and record in real time the pre-tightening force distribution difference data information applied to the bolts in the flange joint surface of the wind tower, wherein the pre-tightening force distribution difference data information applied to the bolts includes the pre-tightening force values ​​Ys applied to a plurality of groups of bolts in the flange joint surface of the wind tower, and extracts the maximum value of the pre-tightening force value Ys therefrom;

[0068] The existing damage monitoring unit is used to record the existing crack state information in the flange joint surface in real time, wherein the existing crack state information includes the crack width Lsc, crack density Lwmd and crack depth Lwsd in the current flange joint surface;

[0069] The bearing capacity monitoring unit is used to monitor and record relevant bearing degree data information of the flange joint surface connecting the tower sections, wherein the relevant bearing degree data information includes the number of stress cycles Yxcs and fatigue strength Qqd of the flange joint surface under cyclic load, and the wind load borne by the wind turbine at the top of the wind tower. The wind load difference Fzcz is obtained based on the wind load monitored during the monitoring period.

[0070] In this embodiment, the preliminary monitoring unit monitors and records the difference data information of the preload force distribution applied to the bolts in the flange joint surface of the wind turbine tower in real time to ensure that the preload force applied to the bolts is evenly distributed; by extracting the maximum value of the preload force value Ys, the problem of uneven preload force distribution can be discovered and corrected in time, stress concentration and potential damage to the flange joint surface caused by uneven preload force can be prevented, and the connection reliability of the flange joint surface can be improved. The existing damage monitoring unit records the existing crack state information in the flange joint surface in real time. Through accurate monitoring of the crack state, it can timely discover and evaluate the degree of damage to the flange joint surface, which is helpful to identify potential structural problems at an early stage, take corresponding maintenance measures, and extend the service life of the wind turbine tower. The bearing capacity monitoring unit monitors and records the relevant bearing degree data information of the flange joint surface. By monitoring the stress and fatigue of the flange under cyclic load, the bearing capacity of the flange joint surface can be comprehensively evaluated to ensure its structural stability in long-term operation. The bearing capacity monitoring unit obtains the wind load difference Fzcz based on the wind load data within the monitoring period. Through accurate monitoring of the wind load, it can understand the stress conditions of the wind tower under different working conditions, predict the impact of the wind load on the flange joint surface, provide a scientific basis for structural health assessment, and ensure the safe operation of the wind tower under severe climatic conditions. Through the coordinated work of the preliminary monitoring unit, the existing damage monitoring unit and the bearing capacity monitoring unit, the system realizes multi-dimensional monitoring and comprehensive analysis of the flange joint surface. Accurate monitoring data and timely early warning information help maintenance personnel take scientific maintenance measures, significantly improve the operational reliability and safety of wind towers, extend their service life, and reduce maintenance costs and failure rates.

[0071] Example 4

[0072] Please refer to Figure 1 ,Specifically: the bolt force distribution module includes a preliminary analysis unit and a preliminary warning unit;

[0073] The preliminary analysis unit is used to extract and obtain the preload force distribution difference data information applied to the bolt, and calculate the preload force mean difference value Yscz. The preload force mean difference value Yscz is obtained by the following formula:

[0074]

[0075] In the formula, Ys min It is expressed as the minimum value of the preload force applied to the bolt in the bolt hole, Ys max It is expressed as the maximum value of the preload force applied to the bolt in the bolt hole, Ys avg It is expressed as the average value of the preload applied to all bolts in the bolt hole.

[0076] The pre-tightening force value Ys applied to the bolt can be monitored by a strain sensor or a pressure sensor to monitor the stress condition of the bolt.

[0077] The preliminary warning unit is used to pre-set a difference threshold L, and compare and analyze the preload force average difference value Yscz with the difference threshold L to determine whether the tightening state of the flange joint surface between the current connecting tower sections is normal. The specific contents are as follows:

[0078] If the preload force mean difference value Yscz exceeds the difference threshold value L, it means that the tightening state in the flange joint surface of the current connecting tower section is not normal, and a preliminary warning instruction will be issued to the outside for further analysis;

[0079] If the preload force average difference value Yscz does not exceed the difference threshold value L, it indicates that the tightening state in the flange joint surface between the current connecting tower sections is normal.

[0080] In this embodiment, the preliminary warning unit pre-sets the difference threshold L, and compares and analyzes the average difference value Yscz of the preload force with the difference threshold L to determine the tightening state of the flange joint surface. When the average difference value Yscz of the preload force exceeds the difference threshold L, the system will immediately issue a preliminary warning instruction, indicating that the tightening state in the flange joint surface is abnormal and needs further analysis and processing. This warning mechanism can timely identify potential problems, prevent structural damage caused by uneven preload force, and further improve the safety and reliability of the system. By monitoring and warning the average difference value Yscz of the preload force, the system can effectively prevent stress concentration and potential damage to the flange joint surface caused by uneven preload force. Timely detection and processing of abnormal tightening state can avoid the occurrence of cracks and other structural damage, extend the service life of the wind tower, and reduce the cost of maintenance and replacement. The precise analysis and real-time warning function of the bolt force distribution module helps maintenance personnel to timely understand the tightening state of the flange joint surface, take corresponding maintenance measures, and ensure the safe operation of the wind tower under various working conditions. This mechanism greatly improves the operational reliability of wind towers, reduces the number and duration of failures and downtime caused by tightening problems, and realizes automatic monitoring and early warning of the flange joint surface of wind towers, reduces reliance on manual inspections, and improves the efficiency and accuracy of monitoring. Through automated tightening status assessment and early warning, maintenance personnel can respond more quickly and accurately, improving the overall intelligent level of maintenance management. In summary, the system realizes accurate monitoring and intelligent early warning of the tightening status through the preliminary analysis unit and preliminary early warning unit of the bolt force distribution module, solves the limitations of traditional methods, and provides a more reliable and efficient wind tower structural stability assurance solution.

[0081] Example 5

[0082] Please refer to Figure 1 ,Specifically: the bonding surface state prediction module includes an external analysis unit, an internal analysis unit and a comprehensive analysis unit;

[0083] The external analysis unit is used to perform linear normalization processing on the crack depth Lwsd and the crack density Lwmd according to the existing crack state information, and map the corresponding data values ​​in the interval [0,1], and then obtain the crack presentation coefficient Lcxs according to the following formula:

[0084]

[0085] Wherein, Lsc represents the crack width, a1 represents the weight coefficient of the sum of the crack depth Lwsd and the crack width Lsc, a2 represents the weight coefficient of the crack density Lwmd, and V represents the first correction constant, wherein 0<a1≤1, 0<a2≤1, and a1+a2=1.

[0086] The above-mentioned crack depth Lwsd and crack width Lsc can be monitored by a crack monitoring instrument, an ultrasonic testing instrument or a laser measuring instrument;

[0087] The crack density Lwmd can be obtained by counting the number of cracks or by image analysis.

[0088] The internal analysis unit is used to obtain the joint surface load bearing coefficient Ccxs by associating the stress cycle number Yxcs and the wind load difference Fzcz according to the relevant load degree data information and performing linear normalization processing. The joint surface load bearing coefficient Ccxs is obtained by the following formula:

[0089]

[0090] Wherein, Qqd represents fatigue strength, α and β are weight coefficients, wherein 0<α≤1, 0<β≤1, and α+β=1.

[0091] The above fatigue strength Qqd can be obtained by experimental testing using a metal fatigue testing machine;

[0092] The number of stress cycles Yxcs can be monitored by strain sensors or stress sensors, or calculated through historical data records and simulations;

[0093] The wind load difference Fzcz can be calculated by monitoring the changes in wind speed and wind direction through wind speed sensors and wind direction sensors, and then combining with the wind mechanics model.

[0094] In this embodiment, by calculating the crack presentation coefficient Lcxs, an accurate assessment of the crack state is achieved, which can accurately reflect the crack distribution and development of the flange joint surface, and provide reliable data support for further risk assessment. The internal analysis unit calculates the joint surface load bearing coefficient Ccxs based on the relevant load-bearing degree data information, and comprehensively evaluates the load bearing capacity of the flange joint surface, which can accurately identify the bearing capacity of the flange joint surface under cyclic load and wind load, and provide a scientific basis for judging the structural stability of the flange joint surface.

[0095] By comprehensively considering multiple parameters, the system can provide timely warnings at the early stage of a problem, further preventing small problems from evolving into major failures, and improving the safety of wind tower operation. Through accurate prediction and real-time warning of the risk of cracking on the flange joint surface, the system can effectively avoid structural damage caused by crack expansion, extend the service life of the wind tower, and reduce maintenance costs and failure rates.

[0096] Example 6

[0097] Please refer to Figure 1Specifically: the comprehensive analysis unit is used to fit and analyze the structural stability evaluation index Jpzs of the wind turbine generator by associating the crack presentation coefficient Lcxs and the bonding surface load bearing coefficient Ccxs according to the bonding surface state set. The structural stability evaluation index Jpzs is obtained by the following formula:

[0098]

[0099] Wherein, F1, F2 and F3 are weight coefficients of the joint surface load bearing coefficient Ccxs, the crack presentation coefficient Lcxs and the preload mean difference Yscz, respectively, wherein, 0<F1≤1, 0<F2≤1, 0<F3≤1, and F1+F2+F3=1, and R is represented as the second correction constant.

[0100] The early warning management module includes an evaluation unit and a management unit;

[0101] The evaluation unit is used to compare and analyze the structural stability evaluation index Jpzs with the evaluation threshold W to comprehensively judge the influence of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine. The specific contents are as follows:

[0102] If the structural stability assessment index Jpzs> the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in an abnormal state, and a continuous red warning is issued;

[0103] If the structural stability assessment index Jpzs = the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in an abnormal state, and a continuous yellow warning is issued;

[0104] If the structural stability assessment index Jpzs is less than the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in a normal state, and three flashing green warnings are issued;

[0105] The management unit is used to take corresponding early warning protection measures according to the corresponding early warning results obtained in the evaluation unit, and the specific contents are as follows:

[0106] If a persistent red warning is issued, the wind turbine will be shut down immediately to prevent further damage and safety accidents, and professional technicians will be arranged to conduct further inspections, including inspections of the flange joint surface and the bolt connection inside the flange. According to the inspection results, necessary repairs and maintenance work will be carried out to repair cracked flange joint surfaces, replace damaged bolts or other damaged parts, and adjust the pre-tensioning force applied to the bolts in each bolt hole to keep it within a fixed range. After the repair, the structural stability assessment will be carried out again to ensure that the wind tower and flange joint surface are restored to normal operating conditions. The detailed data and processing process of this warning event will be recorded, the cause will be analyzed, and preventive measures will be formulated to avoid the recurrence of similar problems.

[0107] If a continuous yellow warning is issued, while the wind turbine is in operation, a time period is limited and professional technicians are arranged on-site to monitor the joint surface of the wind tower and flange and tighten the bolts during this time period. At the same time, the wind speed changes around the wind tower are monitored in the background, the frequency of data collection and inspection is increased, and close attention is paid to structural changes;

[0108] If three flashing green warnings are issued, regular inspections and maintenance will continue according to the normal maintenance plan to ensure the continued stability of the flange joint surface. This standardized maintenance process can ensure the long-term stable operation of the wind tower structure, extend the service life of the equipment, and reduce maintenance costs and failure rates.

[0109] In this embodiment, through the early warning management module, the system can intelligently judge the impact of the risk of cracking of the flange joint surface of the wind turbine tower on the structural stability of the wind turbine generator, and take corresponding early warning protection measures according to the evaluation results. This intelligent management method can improve the timeliness and accuracy of the early warning, effectively avoid safety accidents and losses caused by structural problems, and take preventive measures in advance. According to the judgment results of the evaluation unit, the early warning management module establishes a multi-level early warning system, including a continuous red warning, a continuous yellow warning, and a three-flash green warning. This multi-level early warning system can accurately warn according to the severity of the risk of cracking of the flange joint surface of the wind turbine tower, and take corresponding countermeasures in time to ensure the safe and stable operation of the wind power generation system. Through timely maintenance and monitoring measures, the damage and failure of the wind turbine tower structure can be effectively reduced, and the reliability and stability of the system can be improved. In summary, the wind turbine tower flange joint surface cracking monitoring and early warning system provided by the system realizes comprehensive protection of the safe and stable operation of the wind power generation system through the multi-level early warning system and intelligent management method of the early warning management module, and has significant practicality and promotion value.

[0110] Example 7

[0111] Please refer to Figure 1 and Figure 2Specifically: A wind tower flange joint surface cracking monitoring and early warning method comprises the following steps:

[0112] Step 1: First, deploy several groups of sensors around the flange joint surface of the wind tower connecting the tower sections, collect relevant data information obtained by the several groups of sensors, and upload the relevant data information to the cloud server;

[0113] Step 2: monitor the distribution difference data of the preload force applied to the bolts in the flange joint surface of the wind tower in real time, and record the existing crack status information in the flange joint surface in real time. At the same time, during the operation of the wind turbine at the top of the wind tower, monitor and record the relevant load-bearing data of the flange joint surface connecting the tower sections;

[0114] Step 3: Then pre-process the preload force distribution difference data information, the existing crack state information and the related load-bearing degree data information, and summarize and generate a combination surface state set;

[0115] Step 4: Based on the processed preload force distribution difference data information applied to the bolt, calculate and obtain the preload force average difference value Yscz. If the preload force average difference value Yscz exceeds the difference threshold value L, issue a preliminary warning instruction externally;

[0116] Step 5. After receiving the preliminary warning instruction, the processed joint surface state set is subjected to feature extraction to obtain the crack depth Lwsd, crack density Lwmd, stress cycle number Yxcs and wind load difference Fzcz respectively, and the crack presentation coefficient Lcxs and joint surface load bearing coefficient Ccxs of the flange joint surface are calculated through the trained joint surface crack prediction model. By correlating the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs, the structural stability assessment index Jpzs of the wind turbine is fitted and analyzed;

[0117] Step 6: pre-set an assessment threshold W, and compare and analyze the assessment threshold W with the structural stability assessment index Jpzs to comprehensively judge the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine, and take corresponding early warning protection measures.

[0118] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wind tower flange joint surface crack monitoring and early warning system, characterized in that: It includes deployment module, data monitoring module, data processing module, bolt force distribution module, joint surface state prediction module and early warning management module; The deployment module is used to deploy several groups of sensors around the flange joint surfaces of the wind tower connecting the tower sections in advance, collect relevant data information obtained by the several groups of sensors, and upload the relevant data information to the cloud server; The data monitoring module is used to monitor the preload distribution difference data information applied to the bolts in the flange joint surface of the wind tower in real time, and to record the existing crack status information in the flange joint surface in real time. At the same time, during the operation of the wind turbine generator at the top of the wind tower, the relevant load-bearing degree data information of the flange joint surface connecting the tower sections is monitored and recorded; The data processing module is used to perform data preprocessing on the preload force distribution difference data information, the existing crack state information and the related load-bearing degree data information, and summarize and generate a combination surface state set; The bolt force distribution module is used to calculate and obtain the average difference value Yscz of the preload force based on the processed preload force distribution difference data information applied to the bolt, and if the average difference value Yscz of the preload force exceeds the difference threshold value L, a preliminary warning instruction is issued externally; The joint surface state prediction module is used to extract features from the processed joint surface state set after receiving the preliminary warning instruction, so as to obtain the crack depth Lwsd, the crack density Lwmd, the stress cycle number Yxcs and the wind load difference Fzcz respectively, and calculate the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs of the flange joint surface through the trained joint surface crack prediction model, and fit and analyze the structural stability assessment index Jpzs of the wind turbine by correlating the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs; The early warning management module is used to pre-set an evaluation threshold W, and compare and analyze the evaluation threshold W with the structural stability evaluation index Jpzs to comprehensively judge the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine, and take corresponding early warning protection measures.

2. A wind tower flange joint surface crack monitoring and early warning system according to claim 1, characterized in that: The deployment module includes a sensor building unit and a transmission unit; The sensor construction unit is used to deploy several groups of sensors around the flange joint surface of the wind tower connecting the tower sections, wherein the several groups of sensors include strain sensors, load sensors, vibration sensors, temperature sensors, crack monitoring instruments, metal fatigue testing machines and wind speed sensors; The transmission unit is used to transmit relevant data information obtained by several groups of sensors to a cloud server via a wireless network to support remote monitoring and maintenance, and temporarily store the relevant data information obtained by several groups of sensors when communication transmission is interrupted. At the same time, an edge computing function is integrated in the transmission unit to perform preliminary processing on the relevant data information obtained by several groups of sensors.

3. A wind tower flange joint surface crack monitoring and early warning system according to claim 2, characterized in that: The data monitoring module includes a preliminary monitoring unit, an existing damage monitoring unit and a bearing capacity monitoring unit; The preliminary monitoring unit is used to monitor and record in real time the pre-tightening force distribution difference data information applied to the bolts in the flange joint surface of the wind tower, wherein the pre-tightening force distribution difference data information applied to the bolts includes the pre-tightening force values ​​Ys applied to a plurality of groups of bolts in the flange joint surface of the wind tower, and extracts the maximum value of the pre-tightening force value Ys therefrom; The existing damage monitoring unit is used to record the existing crack status information in the flange joint surface in real time, wherein the existing crack status information includes the current crack width in the flange joint surface , crack density Lwmd and crack depth Lwsd; The bearing capacity monitoring unit is used to monitor and record relevant bearing degree data information of the flange joint surface connecting the tower sections, wherein the relevant bearing degree data information includes the number of stress cycles Yxcs and fatigue strength Qqd of the flange joint surface under cyclic load, and the wind load borne by the wind turbine at the top of the wind tower. The wind load difference Fzcz is obtained based on the wind load monitored during the monitoring period.

4. A wind tower flange joint surface crack monitoring and early warning system according to claim 3, characterized in that: The bolt force distribution module includes a preliminary analysis unit and a preliminary warning unit; The preliminary analysis unit is used to extract and obtain the preload force distribution difference data information applied to the bolt, and calculate and obtain the preload force average difference value Yscz.

5. A wind tower flange joint surface crack monitoring and early warning system according to claim 4, characterized in that: The preliminary warning unit is used to pre-set a difference threshold L, and compare and analyze the preload average difference value Yscz with the difference threshold L to determine whether the tightening state of the flange joint surface between the current connecting tower sections is normal. The specific contents are as follows: If the preload force mean difference value Yscz exceeds the difference threshold value L, it means that the tightening state in the flange joint surface of the current connecting tower section is not normal, and a preliminary warning instruction will be issued to the outside for further analysis; If the preload force average difference value Yscz does not exceed the difference threshold value L, it indicates that the tightening state in the flange joint surface between the current connecting tower sections is normal.

6. A wind tower flange joint surface crack monitoring and early warning system according to claim 5, characterized in that: The joint surface state prediction module includes an external analysis unit, an internal analysis unit and a comprehensive analysis unit; The external analysis unit is used to perform linear normalization processing on the crack depth Lwsd and the crack density Lwmd according to the existing crack state information, and map the corresponding data values ​​in the interval [0,1] to obtain the crack presentation coefficient Lcxs.

7. A wind tower flange joint surface crack monitoring and early warning system according to claim 6, characterized in that: The internal analysis unit is used to obtain the joint surface load bearing coefficient Ccxs by correlating the stress cycle number Yxcs and the wind load difference Fzcz according to the relevant load-bearing degree data information and performing linear normalization processing.

8. A wind tower flange joint surface crack monitoring and early warning system according to claim 6, characterized in that: The comprehensive analysis unit is used to fit and analyze the structural stability evaluation index Jpzs of the wind turbine generator by correlating the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs according to the joint surface state set.

9. A wind tower flange joint surface crack monitoring and early warning system according to claim 1, characterized in that: The early warning management module includes an evaluation unit and a management unit; The evaluation unit is used to compare and analyze the structural stability evaluation index Jpzs with the evaluation threshold W to comprehensively judge the influence of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine. The specific contents are as follows: If the structural stability assessment index Jpzs> the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in an abnormal state, and a continuous red warning is issued; If the structural stability assessment index Jpzs = the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in an abnormal state, and a continuous yellow warning is issued; If the structural stability assessment index Jpzs is less than the assessment threshold W, it means that the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine is in a normal state, and three flashing green warnings are issued; The management unit is used to take corresponding early warning protection measures according to the corresponding early warning results obtained in the evaluation unit, and the specific contents are as follows: If a continuous red warning is issued, the wind turbine will be shut down immediately and professional technicians will be arranged to conduct further inspections, including inspections of the flange joint surface and the bolt connections inside the flange. According to the inspection results, necessary repairs and maintenance work will be carried out to repair the cracked flange joint surface, replace damaged bolts, and adjust the pre-tensioning force applied to the bolts in each bolt hole to keep it within a fixed range. After the repairs, the structural stability assessment will be carried out again; If a continuous yellow warning is issued, while the wind turbine is in operation, a time period is limited and professional technicians are arranged on-site to monitor the joint surface of the wind tower and flange and tighten the bolts during this time period. At the same time, the wind speed changes around the wind tower are monitored in the background, the frequency of data collection and inspection is increased, and close attention is paid to structural changes; If three flashing green warnings are issued, regular inspections and maintenance will continue according to the normal maintenance plan.

10. A method for monitoring and warning cracks on the joint surface of a wind turbine tower flange, comprising a monitoring and warning system for monitoring and warning cracks on the joint surface of a wind turbine tower flange according to any one of claims 1 to 9, characterized in that: The following steps are included: Step 1: First, deploy several groups of sensors around the flange joint surface of the wind tower connecting the tower sections, collect relevant data information obtained by the several groups of sensors, and upload the relevant data information to the cloud server; Step 2: monitor the distribution difference data of the preload force applied to the bolts in the flange joint surface of the wind tower in real time, and record the existing crack status information in the flange joint surface in real time. At the same time, during the operation of the wind turbine at the top of the wind tower, monitor and record the relevant load-bearing data of the flange joint surface connecting the tower sections; Step 3: Then pre-process the preload force distribution difference data information, the existing crack state information and the related load-bearing degree data information, and summarize and generate a combination surface state set; Step 4: Based on the processed preload force distribution difference data information applied to the bolt, calculate and obtain the preload force average difference value Yscz. If the preload force average difference value Yscz exceeds the difference threshold value L, issue a preliminary warning instruction externally; Step 5. After receiving the preliminary warning instruction, the processed joint surface state set is subjected to feature extraction to obtain the crack depth Lwsd, crack density Lwmd, stress cycle number Yxcs and wind load difference Fzcz respectively, and the crack presentation coefficient Lcxs and joint surface load bearing coefficient Ccxs of the flange joint surface are calculated through the trained joint surface crack prediction model. By correlating the crack presentation coefficient Lcxs and the joint surface load bearing coefficient Ccxs, the structural stability assessment index Jpzs of the wind turbine is fitted and analyzed; Step 6: pre-set an assessment threshold W, and compare and analyze the assessment threshold W with the structural stability assessment index Jpzs to comprehensively judge the impact of the current wind tower flange joint surface cracking risk on the structural stability of the wind turbine, and take corresponding early warning protection measures.

Images