Fan blade root bolt monitoring method and monitoring system

Abstract

The application discloses a kind of fan blade root bolt monitoring method and monitoring system, comprising the following steps: the blade root corresponding hub cooperation area is fan-shaped partition, monitoring and obtaining the bolt overall load pressure variation value in all the abnormal area, the fan-shaped partition of bolt load abnormality occurs is determined by the load pressure numerical value of load component;Monitoring and obtaining the independent load condition between every two bolts in the fan-shaped partition of bolt load abnormality, and determining the specific position of the bolt that fails according to the difference of the independent load condition.Through the setting of threshold range A and threshold range B, the abnormal position bolt is judged, the corresponding value of observation mark ruler and physical target can be analyzed, which bolt in adjacent bolt occurs abnormality, the blade root is fixed on the bolt fixing part of partition whole fixed, while realizing abnormal load bolt position monitoring function.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wind power generation monitoring, and particularly relates to a wind turbine blade root bolt monitoring method and a monitoring system. BACKGROUND

[0002] The "Analysis of the Causes of Bolt Fracture Failure of Wind Turbine Blades" with the classification number TH131.3 describes a wind turbine blade root bolt monitoring method, specifically installing a gasket type pressure sensor below the nut, and the load of the bolt can be reflected on the gasket type pressure sensor in real time, and through a data acquisition instrument, the stress condition of the blade bolt during the operation of the wind turbine can be known. The "Analysis of the Causes of Blade Root Bolt Fracture Failure" with the document number 1671-5292(2013)03-0077-04 describes the causes of blade root bolt fracture and monitoring suggestions. The "Research on the Lubrication Method of the Blade Root Bolts of a 850kW Wind Turbine" by Ren Hui describes the relationship between the blade root bolt pre-tightening force and the rotation of the lubrication method.

[0003] For example, the Chinese patent with the publication number CN114941610A discloses a wind turbine blade root bolt monitoring method and a monitoring system. The monitoring method includes: monitoring and obtaining the load conditions of each bolt at the blade root, and dividing the area where the bolt with a larger load is located into a key monitoring area; monitoring and obtaining the gap changes between the blade root and the hub at all the key monitoring areas; and judging the health status of the corresponding bolt according to the gap changes at each key monitoring area. The monitoring method adopts a monitoring idea of pushing from the whole to the details, first measures the load conditions of each bolt at the blade root, and then monitors the gap changes at the key monitoring areas according to the specific conditions, which can not only monitor whether the bolt is damaged, but also judge the main cause of the bolt damage according to the load monitoring result, and fundamentally find the load source of the bolt failure.

[0004] However, the above-mentioned scheme has the following disadvantages: the patent file monitors the gap changes between the key areas of the blade root and the hub and the load of the corresponding bolt, realizes continuous analysis of the monitoring data on the load distribution law and the load source of the blade root bolt, optimizes the arrangement position of the sensor, and reduces the number of sensors. However, the number of wind turbine blade root bolts is large, and although the load of each bolt can be roughly estimated according to the load distribution law of the bolt and the load sensor arranged, the position of the abnormal bolt cannot be determined. In addition, the cooperation pre-tightening force of the bolt and the nut on the blade root has a relationship with the use of the gasket and the lubricating oil. How to adjust the gasket, fix the fixed part of the bolt on the blade root in a partitioned and integral manner, and realize the abnormal load bolt position monitoring function is a problem to be solved at present. SUMMARY

[0005] The application aims to provide a fan blade root bolt monitoring method and a monitoring system to solve the problems in the background art.

[0006] To achieve the above-mentioned purpose, the application provides the following technical solutions.

[0007] A fan blade root bolt monitoring method comprises the following steps.

[0008] The blade root corresponding to the hub fitting area is divided into sectors, the overall load of the bolts in each sector is monitored, and the sector with a larger overall load is defined as an abnormal area;

[0009] The overall load pressure change value of the bolts in all abnormal areas is monitored and obtained, and the sector with bolt load abnormality is determined through the load pressure value of the load assembly;

[0010] The independent load between each two bolts in the sector with bolt load abnormality is monitored and obtained, and the specific position of the faulty bolt is determined according to the different independent load conditions.

[0011] Preferably, the overall load pressure change value of the bolts in all abnormal areas is monitored and obtained, and the sector with bolt load abnormality is determined, specifically comprising:

[0012] A load assembly for transmitting the overall load of the bolts is arranged on each abnormal area, the bending moment load received by the load assembly is measured by a load sensor, a bending moment load normal threshold range A is set, and it is determined whether the bending moment load is within the threshold range A, if not, the sector position with abnormality is determined.

[0013] Preferably, the independent load between each two bolts in the sector with bolt load abnormality is monitored and obtained, and the specific position of the faulty bolt is determined according to the different independent load conditions, specifically comprising:

[0014] The independent load value between each two bolts is measured and obtained by the distance motion of the load sensor, the independent load values obtained by measurement are compared one by one, and a normal range threshold B of the independent load value between adjacent two bolts is set.

[0015] If a group of independent load values are outside the threshold B, it is determined that the two bolts corresponding to the group of independent load values have faults;

[0016] If at least two groups of the independent load values are outside the threshold value B, the at least two groups of the abnormal independent load values are judged, and the position of the larger independent load value is determined as the position of the main abnormal bolt.

[0017] Preferably, the load assembly includes a force measuring base plate integrally sleeved on the plurality of bolts in each sector, which is arranged in an arc shape and serves as a gasket for transmitting the load of the bolts, and the force measuring base plate is arranged between the hub and the nut fitting part.

[0018] When the load sensor moves to the middle position of the load bearing plate, the bending moment load value transmitted by the bolt to the load assembly is obtained.

[0019] When the load sensor moves towards both sides of the middle of the load bearing plate, the independent load value between adjacent bolts is obtained.

[0020] Preferably, the sectors at the positions of the 45°, -45°, 90° and 0° load concentration points of the blade root are divided into abnormal prone areas.

[0021] The normal threshold value range A of the abnormal prone areas in the 45°, -45°, 90° and 0° areas is adjusted according to the stress condition of the blade root.

[0022] Preferably, a monitoring data processing center is arranged on the blade root and is used to collect, store and process the threshold value range A and threshold value range B change data in sequence, finally obtain the position of the adjacent abnormal bolt according to the threshold value range B change data, and determine the position of the abnormal bolt through the position marking assembly.

[0023] A fan blade root bolt monitoring system using the fan blade root bolt monitoring method, comprising:

[0024] A load monitoring partition module, which includes sectoring the blade root corresponding to the hub fitting area, monitoring the overall load of the bolts in each sector, and dividing the sector with larger overall load as an abnormal prone area, and integrally installing the plurality of bolts in the sector through the force measuring base plate.

[0025] A monitoring module, which includes a load sensor that can slide at a certain distance and is used to detect the bending moment load of the load assembly and the independent load value between adjacent bolts, respectively.

[0026] A judgment module, which compares the bending moment load value and the independent load value obtained through the monitoring data processing center with the threshold value range A and the threshold value range B, respectively, determines the position of the abnormal sector and the position of the adjacent abnormal bolt, and finally determines the specific position of the abnormal bolt according to the position marking assembly.

[0027] Preferably, the force measurement pad is provided with mounting holes, and the bolts pass through the mounting holes, the force measurement pad is provided with a monitoring groove on the upper end surface, a load bearing plate is movably arranged in the monitoring groove, and the load sensor detection end is arranged on the lower end of the load bearing plate, a linear slide is arranged on the upper end of the monitoring groove, the load sensor is arranged on the linear slide, the linear slide control end is electrically connected with the monitoring data processing center, and the linear slide drives the load sensor to linearly reciprocate along the monitoring groove, the mounting hole is provided with a lower pressing arc groove in communication with the monitoring groove, and a lower pressing arc block is elastically inserted into the lower pressing arc groove and extends above the load bearing plate.

[0028] Preferably, the load bearing plate is provided with a push arc spring plate in contact with the lower pressing arc block on the upper end surface, and the mounting hole is further provided with an elastic pad around the mounting hole, and the bolt fixed end nut locking surface is in contact with the lower pressing arc block and the elastic pad in sequence.

[0029] The monitoring groove is provided with a limiting rod on both sides of the inner bottom end surface, the load bearing plate is provided with a limiting hole corresponding to the limiting rod on the upper end surface, and the limiting rod slides out of the limiting hole, the lower pressing arc groove is provided with an upper pushing spring block on the inner bottom end surface, and the upper pushing spring block generates a reset pushing force in the upward direction on the lower pressing arc block.

[0030] Preferably, the lower pressing arc groove is provided with a physical marker on the end surface, and the lower pressing arc block is provided with a marker scale plate on the upper end surface, the physical marker is corresponding to the scale value on the marker scale plate and is used for recording the position state of the bolt fixed end.

[0031] Compared with the prior art, the beneficial effects of the present application are:

[0032] The force measurement pad is used as a gasket on the bolt, when the linear slide drives the load sensor to move to the middle position of the monitoring groove, the force measurement pad is provided with a plurality of bolts, the bolt is sequentially passed through the nut, the lower pressing arc block, the push arc spring plate and the load bearing plate, the bending moment load is transmitted to the load sensor in the middle position and is monitored, the value and the threshold range A are compared, if the value is not in the threshold A range, it indicates that the corresponding fan-shaped partition bolt is abnormal.

[0033] The linear sliding table drives the load sensor to reciprocate in the monitoring groove, the load sensor moves a fixed distance each time, and is located below the load bearing plate corresponding to the middle point of the adjacent bolt after each movement, at this time, the independent load value of the corresponding adjacent bolt part is obtained, and the obtained value is compared with the threshold range B, when the value is not in the range, it indicates that the adjacent bolt part is abnormal, at the same time, the pressure of the nut on the abnormal position bolt on the corresponding position is different from that of the two side bolts, so that the pressing height of the lower pressing arc block overcoming the top pushing arc spring sheet changes obviously, only by observing the corresponding value of the mark ruler plate and the physical target, the abnormal bolt in the adjacent bolt can be analyzed, and the adjacent bolt part is fixed, the abnormal load bolt position monitoring function is realized. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a blade root bolt monitoring method flowchart of the application;

[0035] Figure 2 It is a main view schematic diagram of the force measurement pad plate of the application;

[0036] Figure 3 It is a force measurement pad plate local schematic diagram of the application; Figure 2

[0037] Figure 4 It is a bolt area local sectional view schematic diagram of the application; Figure 3

[0038] Figure 5 It is a nut and force measurement pad plate cooperation area local schematic diagram of the application; Figure 4

[0039] Figure 6 It is a force measurement pad plate and load bearing plate separation structure schematic diagram of the application;

[0040] Figure 7 It is a linear sliding table and force measurement pad plate sliding cooperation area sectional view schematic diagram of the application; Figure 6

[0041] Figure 8 It is a load bearing plate and load sensor state schematic diagram under different forces and positions of the application.

[0042] In the figure: 1, bolt; 2, force measurement pad plate; 3, nut; 4, load sensor; 5, physical target; 6, mounting hole; 7, monitoring groove; 8, load bearing plate; 9, lower pressing arc groove; 10, lower pressing arc block; 11, top pushing arc spring sheet; 12, elastic pad block; 13, limiting rod; 14, limiting hole; 15, upper pushing spring block; 16, mark ruler plate; 101, blade root; 102, hub; 201, linear sliding table. ​​​​DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described in connection with the drawings in the embodiments of the present application.

[0044] Please refer to Figures 1-8 The present application provides a technical solution:

[0045] Embodiment one:

[0046] A fan blade root bolt monitoring method, comprising the following steps:

[0047] S101. The blade root 101 corresponding to the hub 102 fitting area is divided into sectors, the overall load of the bolts 1 in each sector is monitored, and the sector with larger overall load is divided as an abnormal area;

[0048] S102. The overall load pressure change value of the bolts 1 in all abnormal areas is monitored and obtained, and the sector with bolt 1 load abnormality is determined through the load pressure value of the load assembly;

[0049] S103. The independent load between each two bolts 1 in the sector with bolt 1 load abnormality is monitored and obtained, and the specific position of the bolt 1 with fault is determined according to the different independent load conditions.

[0050] Embodiment two:

[0051] On the basis of embodiment one, it is further explained that the overall load pressure change value of the bolts 1 in all abnormal areas is monitored and obtained, and the sector with bolt 1 load abnormality is determined, which specifically includes:

[0052] A load assembly for transmitting the overall load of the bolts 1 is arranged on each abnormal area, the bending moment load received by the load assembly is measured overall by the load sensor 4, a bending moment load normal threshold range A is set, and it is determined whether the bending moment load is within the threshold range A, if it is outside the threshold range A, the sector position with abnormality is determined.

[0053] Embodiment three:

[0054] On the basis of embodiment one, it is further explained that the independent load between each two bolts 1 in the sector with bolt 1 load abnormality is monitored and obtained, and the specific position of the bolt 1 with fault is determined according to the different load conditions, which specifically includes:

[0055] The independent load value between each two bolts 1 is measured and obtained through the fixed-distance movement of the load sensor 4, the measured independent load values are compared one by one, and a normal range threshold B of the independent load value between adjacent two bolts 1 is set.

[0056] If one of the independent load values is outside the threshold value B, it is determined that the two side bolts 1 corresponding to the independent load value are faulty;

[0057] If at least two of the independent load values are outside the threshold value B, the size of the at least two abnormal independent load values is judged, and the position of the larger independent load value is determined as the position of the main abnormal bolt 1.

[0058] Embodiment four:

[0059] Further based on the embodiment one, the load assembly comprises a force measuring pad 2 which is integrally arranged on each bolt 1 in the fan-shaped partition, is arranged in an arc shape, and is used as a gasket to transmit the load of the bolt 1, and the force measuring pad 2 is arranged between the hub 102 and the nut 3 cooperation part;

[0060] When the load sensor 4 moves to the middle position of the load bearing plate 8, although the pressure values of the upper several downward pressure arc blocks 10 have deviations, the overall pressure is ultimately transmitted to the load bearing plate 8, at this time, the downward pressure of the load bearing plate 8 is relatively concentrated, the threshold range A is obtained when the load sensor 4 is located at the middle position of the load bearing plate 8, specifically, the downward pressure of the load bearing plate 8 is changed through the curve pressure change mode, the curve pressure change range conforms to the indirect bending moment load range of the corresponding fan-shaped zone bolt 1, finally, the data is summarized to obtain the threshold range A, in use, the bending moment load values transmitted by the several bolts 1 to the load assembly are obtained by moving the load sensor 4 to the middle position of the load bearing plate 8, and the corresponding bolt 1 is judged by comparing with the threshold range A whether it is abnormal or not;

[0061] When the load sensor 4 moves to the middle position of the load bearing plate 8, although the pressure values of the upper several downward pressure arc blocks 10 have deviations, the overall pressure is ultimately transmitted to the load bearing plate 8, at this time, the downward pressure of the load bearing plate 8 is relatively concentrated, the threshold range A is obtained when the load sensor 4 is located at the middle position of the load bearing plate 8, specifically, the downward pressure of the load bearing plate 8 is changed through the curve pressure change mode, the curve pressure change range conforms to the indirect bending moment load range of the corresponding fan-shaped zone bolt 1, finally, the data is summarized to obtain the threshold range A, in use, the bending moment load values transmitted by the several bolts 1 to the load assembly are obtained by moving the load sensor 4 to the middle position of the load bearing plate 8, and the corresponding bolt 1 is judged by comparing with the threshold range A whether it is abnormal or not;

[0062] Reference Figure 8 As shown, the load bearing plate 8 is at least divided into four states a, b, c and d:

[0063] a state: deflection movement (measurement value B is formed) of the load sensor 4 moving towards both sides of the load bearing plate 8;

[0064] b state: the force on both sides of the load bearing plate 8 is not evenly distributed (the downward force generated by the bolt changes, which is considered abnormal), and the normal value of the load sensor 4 in the a state will change greatly;

[0065] c state: when the load sensor 4 is located at the middle position of the load bearing plate 8, the unilateral pressure value of the load bearing plate 8 changes and the deflection movement occurs;

[0066] d state: deflection movement when the unilateral downward pressure of the load bearing plate 8 decreases;

[0067] Similarly, the four forms of the load bearing plate 8 formed by the above a, b, c and d are only examples, and there are many similar forms in actual use, which will not be described in detail. The above content shows that through the movement of the load sensor 4, the independent load condition between the adjacent bolts 1 can be indirectly monitored;

[0068] The 45°, -45°, 90° and 0° load concentration points of the blade root 101 are divided into easy abnormal area by sector division;

[0069] According to the stress condition of the blade root 101, the normal threshold range A of the easy abnormal area of the 45°, -45°, 90° and 0° area is adjusted.

[0070] Example five:

[0071] Further based on the embodiment one, a monitoring data processing center is arranged on the blade root 101 and used to collect, store and process the threshold range A and threshold range B change data in sequence, and finally the abnormal adjacent bolt 1 position is obtained according to the threshold range B change data, and the abnormal bolt 1 position is determined through the position marking component.

[0072] Example six:

[0073] A fan blade root bolt monitoring system using a fan blade root bolt monitoring method, comprising:

[0074] A load monitoring partition module, which includes sector partitioning the blade root 101 corresponding to the hub 102 matching area, monitoring the overall load condition of the bolts 1 in each sector partition, and dividing the sector partition with larger overall load into an easy abnormal area, and installing the bolts 1 in the partition through the force measuring pad 2;

[0075] The monitoring module comprises a load sensor 4 arranged to be able to slide at a distance and is used to detect the bending moment load and the independent load value between adjacent bolts 1.

[0076] The judging module compares the bending moment load value and the independent load value with threshold range A and threshold range B respectively through the monitoring data processing center, determines the abnormal sector partition position and the abnormal adjacent bolt 1 position respectively, and finally determines the specific position of the abnormal bolt 1 according to the position marking component.

[0077] Embodiment seven:

[0078] Further illustrated on the basis of embodiment six, the force measurement backing plate 2 is provided with mounting holes 6, and a plurality of bolts 1 penetrate through the corresponding mounting holes 6. The force measurement backing plate 2 is provided with a monitoring groove 7 on the left side of the upper end face. The load bearing plate 8 is movably arranged in the monitoring groove 7. The detection end of the load sensor 4 is arranged at the lower pressing end of the load bearing plate 8 and is used to detect the external pressure received by the load bearing plate 8. A linear sliding table 201 is arranged on the upper port side of the monitoring groove 7. The linear sliding table 201 can be an arc sliding table, and the center of the arc part and the center of the hub 102 coincide. The load sensor 4 is arranged on the linear sliding table 201. The control end of the linear sliding table 201 is electrically connected with the monitoring data processing center. The power end of the linear sliding table 201 is connected with the fan power supply. The monitoring data processing center is an integrated controller, and details are not described herein. The linear sliding table 201 drives the load sensor 4 to perform linear reciprocating motion along the monitoring groove 7. The mounting hole 6 is provided with a lower pressing arc groove 9 which is in communication with the monitoring groove 7. The lower pressing arc block 10 is elastically inserted into the lower pressing arc groove 9 and extends above the load bearing plate 8.

[0079] Embodiment eight:

[0080] Further illustrated on the basis of embodiment six, the load bearing plate 8 is arranged with a push arc spring piece 11 which is in contact with the lower pressing arc block 10. The push arc spring piece 11 will elastically deform under the pressure from above. The mounting hole 6 is further provided with an elastic pad 12. The locking surface of the bolt 1 fixed end nut 3 is in contact with the lower pressing arc block 10 and the elastic pad 12 in sequence. The elastic pad 12 provides elastic support for the bottom end surface of the nut 3 relative to the opposite side of the lower pressing arc block 10.

[0081] Limiting rods 13 are provided on both sides of the bottom surface inside the monitoring groove 7. The upper surface of the load bearing plate 8 is provided with a corresponding limiting hole 14, and the limiting rod 13 slides through the limiting hole 14. The matching arrangement of the limiting rod 13 and the limiting hole 14 prevents the load bearing plate 8 from misaligning and slipping with a large stroke. Similarly, the cross-sectional diameter of the limiting hole 14 is 2mm larger than the cross-sectional diameter of the limiting rod 13, so the load bearing plate 8 is allowed to undergo slight skew deformation when subjected to downward pressure from different positions above. When the load bearing plate 8 is subjected to uneven force on both sides above, the two sides will lift up, which can be detected by the load sensor 4. The bottom surface inside the downward pressure arc groove 9 is provided with an upward push block 15. The upward push block 15 generates an upward reset thrust on the downward pressure arc block 10, providing elastic support.

[0082] A physical mark 5 is provided on the end face of the downward pressing arc groove 9, and a marking ruler 16 is provided on the upper end face of the downward pressing arc block 10. The indicator end of the physical mark 5 and the scale value on the marking ruler 16 correspond to each other and are used to record the position status of the fixing end of the bolt 1.

[0083] The working principle is as follows: By using the force measuring pad 2 as a shim on the bolt 1, when the linear slide 201 drives the load sensor 4 to move to the middle position of the monitoring slot 7, several bolts 1 on the force measuring pad 2 sequentially transmit the bending moment load to the load sensor 4 at the middle position through the nut 3, the pressing arc block 10, the pushing arc spring 11, and the load bearing plate 8, and monitor it. The obtained value is compared with the threshold range A. If the value is not within the threshold range A, it indicates that the bolt 1 in the corresponding sector is abnormal. Then, the linear slide 201 drives the load sensor 4 to reciprocate to both sides inside the monitoring slot 7. The load sensor 4 moves at a fixed distance each time, and after each movement, it is located in the middle of the adjacent bolt 1. Below the load-bearing plate 8 corresponding to the inter-point, the independent load value of the corresponding adjacent bolt 1 is obtained at this time. The obtained value is compared with the threshold range B. When the value is not within the range, it indicates that the location of the adjacent bolt 1 is abnormal. At the same time, the pressure of the nut 3 on the abnormal bolt 1 on the corresponding position of the downward pressing arc block 10 is different from that of the bolts on both sides. Therefore, the downward pressing height of the downward pressing arc block 10 overcoming the pushing arc spring 11 will change significantly. By observing the corresponding values ​​of the marking ruler 16 and the physical mark 5, it is possible to analyze which of the adjacent bolts 1 is abnormal. While fixing the bolt 1 fixing part on the blade root 101 in sections, the abnormal load bolt 1 position monitoring function is realized.

[0084] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that the technical solutions described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalent features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for monitoring bolts at the root of wind turbine blades, characterized in that, The method comprises the following steps: The blade root corresponding to the hub fitting area is sectorally partitioned, the overall load of each sector is monitored, and the sector with a larger overall load is defined as an abnormal area; The overall load pressure change value of the bolt in all abnormal areas is monitored and obtained, and the sector where the bolt load abnormality occurs is determined by the load pressure value of the load component; The independent load between each two bolts in the sector where the bolt load abnormality occurs is monitored and obtained, and the specific position of the faulty bolt is determined according to the different independent load conditions; The overall load pressure change value of the bolt in all abnormal areas is monitored and obtained, and the sector where the bolt load abnormality occurs is determined, specifically comprising: A load component for transmitting the overall load of the bolt is arranged on each abnormal area, the bending moment load of the load component is measured by a load sensor, a bending moment load normal threshold range A is set, and it is determined whether the bending moment load is within the threshold range A, if not, the sector where the abnormality occurs is determined; The independent load between each two bolts in the sector where the bolt load abnormality occurs is monitored and obtained, and the specific position of the faulty bolt is determined according to the different independent load conditions, specifically comprising: The independent load value between each two bolts is measured and obtained by the distance motion of the load sensor, the independent load values obtained by measurement are compared one by one, and a normal range threshold B of the independent load value between adjacent two bolts is set; If a group of independent load values are outside the threshold B, it is determined that the two bolts corresponding to the group of independent load values have faults; If at least two groups of independent load values are outside the threshold B, the sizes of the at least two groups of abnormal independent load values are judged, and the position of the larger independent load value is determined as the main abnormal bolt position.

2. The method of fan blade root bolt monitoring of claim 1, wherein: The load component comprises a force measurement backing plate which is integrally arranged on the bolts in each sector, is arranged in an arc shape, and is used as a gasket to transmit the load of the bolt, and the force measurement backing plate is arranged between the hub and the nut fitting part; When the load sensor moves to the middle position of the load pressure plate, the bending moment load value of the bolt transmitted to the load component is obtained; When the load sensor moves to both sides of the middle part of the load pressure plate, the independent load value between adjacent bolts is obtained.

3. The method of fan blade root bolt monitoring of claim 2, wherein: The sectors where the 45°, -45°, 90° and 0° load concentration points of the blade root are located are divided into abnormal areas; The normal threshold range A of the abnormal areas of the 45°, -45°, 90° and 0° regions is adjusted according to the stress condition of the blade root.

4. The method of fan blade root bolt monitoring of claim 1, wherein: The blade root is provided with a monitoring data processing center and is used for collecting, storing and processing threshold range A and threshold range B change data in sequence, and finally obtaining the abnormal adjacent bolt position according to the threshold range B change data, and determining the abnormal bolt position through the position marking assembly.

5. A wind turbine blade root bolt monitoring system for use in the wind turbine blade root bolt monitoring method of any of claims 1-4, characterized by, Comprise: The load monitoring partition module comprises a fan-shaped partition of the blade root corresponding to the hub fitting area, monitoring the overall load of the bolts in each fan-shaped partition, and dividing the fan-shaped partition with larger overall load into an abnormal area, and installing a plurality of bolts in the partition through the force measuring base plate; The monitoring module comprises a load sensor that can slide at a certain distance and is used for detecting the bending moment load of the load assembly and the independent load value between adjacent bolts; The judgment module compares the bending moment load value and the independent load value obtained by the monitoring data processing center with threshold range A and threshold range B respectively, determines the abnormal fan-shaped partition position and the abnormal adjacent bolt position respectively, and finally determines the specific position of the abnormal bolt according to the position marking assembly.

6. The wind turbine blade root bolt monitoring system according to claim 5, wherein: The force measuring base plate is provided with a mounting hole, and a plurality of bolts penetrate through the mounting hole. The upper end surface of the force measuring base plate is provided with a monitoring groove, and a load bearing plate is movably arranged in the monitoring groove. The detection end of the load sensor is arranged at the lower pressing end of the load bearing plate. A linear sliding table is arranged on the upper end of the monitoring groove. The load sensor is arranged on the linear sliding table. The control end of the linear sliding table is electrically connected with the monitoring data processing center. The linear sliding table drives the load sensor to perform linear reciprocating motion along the monitoring groove. The mounting hole is provided with a lower pressing arc groove which is connected with the monitoring groove. An elastic lower pressing arc block is elastically inserted into the lower pressing arc groove and extends above the load bearing plate.

7. A fan blade root bolt monitoring system according to claim 6, characterised in that: The upper end surface of the load bearing plate is arranged with a push arc elastic piece which is in contact with the lower pressing arc block. The periphery of the mounting hole is also provided with an elastic pad. The locking surface of the bolt fixed end nut is in contact with the lower pressing arc block and the elastic pad in sequence. Limit rods are arranged on both sides of the bottom end surface of the monitoring groove. Limiting holes are arranged on the upper end surface of the load bearing plate, and the limit rods slide through the limiting holes. An upper pushing elastic block is arranged on the bottom end surface of the lower pressing arc groove. The upper pushing elastic block generates a reset thrust in the upward direction to the lower pressing arc block.

8. The wind turbine blade root bolt monitoring system according to claim 6, wherein: A physical mark is arranged on the end surface side of the lower pressing arc groove, and a marking ruler plate is arranged on the upper end surface of the lower pressing arc block. The physical mark is corresponding to the scale value on the marking ruler plate and is used for recording the position state of the bolt fixed end.

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