Monitoring Method and Device for Wind Turbine Tower, Storage Medium, Monitoring System

Abstract

A monitoring method and device, storage medium, and monitoring system for a wind turbine tower. The method includes: obtaining strain results of the wind turbine tower at multiple first preset cross-sections through strain sensors, and calculating the bending moment at each first preset cross-section according to the strain results at each first preset cross-section, where different first preset cross-sections have different heights; fitting the bending moments at multiple first preset cross-sections of the wind turbine tower and the heights of each first preset cross-section to obtain the distribution of the bending moment with height; obtaining the distribution of the stress of the wind turbine tower with height according to the distribution of the bending moment with height and the flexural section modulus of the wind turbine tower; where the flexural section modulus is determined according to the dimensions of the wind turbine tower at the cross-section. Through the solution of the present invention, the wind turbine tower can be monitored accurately and comprehensively.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power, and particularly to a monitoring method and device for a wind turbine tower, a storage medium, and a monitoring system. Background Art

[0002] A wind turbine tower (also known as a wind power tower) is a load-bearing component in a wind power generation unit, which mainly plays a supporting role in the wind power generation unit and can absorb the vibration of the wind power generation unit. During the operation of the wind power generation unit, the wind turbine tower is long-term under the action of wind with irregular, variable speed and variable load, and will also suffer from some sudden natural disasters, such as typhoons, icing, lightning strikes, etc. Therefore, the wind turbine tower will gradually be damaged. If the wind turbine tower is in an abnormal state due to overload, fatigue and other damages, it may lead to serious safety accidents and cause great losses.

[0003] However, in the prior art, there is an inaccurate problem in the stress monitoring of the wind turbine tower. Therefore, there is an urgent need for a monitoring method for the wind turbine tower, which can accurately monitor the stress of the wind turbine tower so as to timely detect the overload abnormality of the wind turbine tower. In addition, there is also a need to comprehensively monitor other aspects of the wind turbine tower. Summary of the Invention

[0004] The technical problem solved by the present invention is how to accurately monitor the stress of the wind turbine tower.

[0005] To solve the above technical problem, an embodiment of the present invention provides a monitoring method for a wind turbine tower, the method includes: obtaining strain results of the wind turbine tower at a plurality of first preset cross-sections through a strain sensor, and calculating the bending moment at each first preset cross-section according to the strain results at each first preset cross-section, where different first preset cross-sections have different heights; fitting the bending moments at the plurality of first preset cross-sections of the wind turbine tower and the heights of each first preset cross-section to obtain the distribution of the bending moment with height; obtaining the distribution of the stress of the wind turbine tower with height according to the distribution of the bending moment with height and the flexural section modulus of the wind turbine tower; where the flexural section modulus is determined according to the dimensions of the wind turbine tower at the cross-section.

[0006] Optionally, fitting the bending moments at the plurality of first preset cross-sections of the wind turbine tower and the heights of each first preset cross-section includes: constructing a polynomial model

[0007] M(H) = k1×H n + k2×H n-1 + k3×H n-2 + …… + k n ×H + k n+1 ,

[0008] Wherein, M(H) is the bending moment of the wind turbine tower at height H, and k1, k2, k3... k n , k n+1 are the parameters of the polynomial model, and n is the highest degree of the polynomial model; the parameters of the polynomial model are solved according to the bending moments of the wind turbine tower at multiple first preset cross-sections and the heights of each first preset cross-section, so as to obtain the distribution of the bending moment with height.

[0009] Optionally, before calculating and determining the bending moment at each first preset cross-section according to the strain result at each first preset cross-section, the method further includes: obtaining the temperature of the wind turbine tower at the multiple first preset cross-sections through a temperature sensor; performing temperature compensation on the strain result at each first preset cross-section according to the temperature of the wind turbine tower at each first preset cross-section.

[0010] Optionally, the method further includes: determining the number of times that the stress of the wind turbine tower at different heights changes from a first preset stress range to a second preset stress range and then changes from the second preset stress range to the first preset stress range within a first preset time range; comparing the number of times with a first preset threshold to determine the fatigue degree of the wind turbine tower at different heights.

[0011] Optionally, the method further includes: displaying a schematic diagram of the wind turbine tower on a user interface; and simultaneously displaying a distribution diagram of the stress of the wind turbine tower with height on the user interface; wherein, the abscissa of the distribution diagram is height, the ordinate is stress, the extending direction of the abscissa on the user interface is parallel to the height direction of the wind turbine tower on the user interface, and the distribution diagram is aligned with the schematic diagram.

[0012] Optionally, the method further includes: obtaining the vibration displacement of the wind turbine tower at at least one second preset cross-section within a second preset time range through a vibration sensor; determining the center position of the circle of each second preset cross-section of the wind turbine tower in the balanced state; determining the vibration trajectory of the wind turbine tower at the second preset cross-section according to the center position of each second preset cross-section and the vibration displacement of the wind turbine tower at the second preset cross-section within the second preset time range; determining the point farthest from a preset origin on the vibration trajectory at the at least one second preset cross-section, wherein the position of the preset origin is the center position of the bottom cross-section of the wind turbine tower when it is installed; determining a vibration trajectory circle, the center of the vibration trajectory circle is the preset origin, and the radius of the vibration trajectory circle is the distance between the point farthest from the preset origin and the preset origin; if the position of the wind turbine tower vibrating at any second preset cross-section exceeds the vibration trajectory circle, it is determined that the vibration state of the wind turbine tower is abnormal.

[0013] Optionally, determining the center positions of each second preset cross-section of the wind turbine tower in the balanced state includes: obtaining a first inclination angle and a second inclination angle of the wind turbine tower in the balanced state through an inclination sensor, where the first inclination angle is the angle at which the bottom cross-section of the wind turbine tower deviates from the vertical direction in the axial direction, and the second inclination angle is the angle at which the top cross-section of the wind turbine tower deviates from the vertical direction in the axial direction; determining the offset of each second preset cross-section of the wind turbine tower in the tower base plane according to the first inclination angle, the second inclination angle, and the height of the wind turbine tower; and determining the center positions of each second preset cross-section according to the position of the preset origin and the offset of each second preset cross-section in the tower base plane.

[0014] Optionally, the at least one second preset cross-section includes: a first preset cross-section with the highest height, and a first preset cross-section with a middle height, where the middle height is the middle value of the heights of the plurality of first preset cross-sections.

[0015] Optionally, the method further includes: obtaining the vibration frequencies of the wind turbine tower at different times at at least one second preset cross-section through an acceleration sensor; determining the natural frequency of the wind turbine tower at the second preset cross-section according to the frequency at each second preset cross-section; calculating the difference between the natural frequency of the wind turbine tower at each second preset cross-section and a preset natural frequency, and if the absolute value of the difference is greater than a second preset threshold, determining that the vibration state of the wind turbine tower is abnormal.

[0016] Optionally, the wind turbine tower has a plurality of flange plates, the wind turbine tower includes multiple sections of cylinders, adjacent cylinders are connected through the flange plates, the lowermost cylinder of the wind turbine tower is connected to the ground anchor through the flange plate, and the first preset cross-section is set at a preset distance from each flange plate.

[0017] Optionally, the strain sensors are installed at the plurality of first preset cross-sections.

[0018] Optionally, the preset distance is 100 millimeters to 500 millimeters.

[0019] Optionally, the method further includes: obtaining the pre-tightening force of the bolts installed on each flange plate through a bolt monitoring sensor, and determining whether each bolt is loose according to the comparison result of the pre-tightening force of each bolt and a preset pre-tightening force threshold.

[0020] To solve the above technical problems, an embodiment of the present invention further provides a monitoring device for a wind turbine tower barrel. The device includes: a first acquisition module, configured to acquire the strain results of the wind turbine tower barrel at a plurality of first preset cross-sections through a strain sensor, and calculate the bending moment at each first preset cross-section according to the strain results at each first preset cross-section, where different first preset cross-sections have different heights; a fitting module, configured to fit the bending moments of the wind turbine tower barrel at a plurality of first preset cross-sections and the heights of each first preset cross-section to obtain the distribution of the bending moment along the height; a stress calculation module, configured to obtain the distribution of the stress of the wind turbine tower barrel along the height according to the distribution of the bending moment along the height and the flexural section modulus of the wind turbine tower barrel; where the flexural section modulus is determined according to the dimensions of the wind turbine tower barrel at the cross-section.

[0021] An embodiment of the present invention further provides a storage medium, on which a computer program is stored. When the computer program is run by a processor, the steps of the above-mentioned monitoring method for the wind turbine tower barrel are executed.

[0022] An embodiment of the present invention further provides a monitoring system for a wind turbine tower barrel. The system includes: a strain sensor, configured to acquire the strain results of the wind turbine tower barrel at a plurality of first preset cross-sections, where different first preset cross-sections have different heights; a controller, configured to calculate the bending moment at each first preset cross-section according to the strain results at each first preset cross-section, fit the bending moments of the wind turbine tower barrel at a plurality of first preset cross-sections and the heights of each first preset cross-section to obtain the distribution of the bending moment along the height, and obtain the distribution of the stress of the wind turbine tower barrel along the height according to the distribution of the bending moment along the height and the flexural section modulus of the wind turbine tower barrel; where the flexural section modulus is determined according to the dimensions of the wind turbine tower barrel at the cross-section.

[0023] Optionally, the system further includes: a temperature sensor, configured to acquire the temperature of the wind turbine tower barrel at a plurality of first preset cross-sections; and the controller is further configured to perform temperature compensation on the strain results at each first preset cross-section according to the temperature of the wind turbine tower barrel at each first preset cross-section.

[0024] Optionally, the system further includes: a vibration sensor, configured to acquire vibration displacements of the wind turbine tower barrel at at least one second preset cross-section within a second preset time range; the controller is further configured to determine the center positions of the respective second preset cross-sections of the wind turbine tower barrel in a balanced state; according to the center positions of each second preset cross-section and the vibration displacements of the wind turbine tower barrel at this second preset cross-section within the second preset time range, determine the vibration trajectories of the wind turbine tower barrel at this second preset cross-section, and determine the point farthest from a preset origin on the vibration trajectories at the at least one second preset cross-section, where the position of the preset origin is the center position of the bottom cross-section of the wind turbine tower barrel during installation, determine a vibration trajectory circle, the center of the vibration trajectory circle is the preset origin, and the radius of the vibration trajectory circle is the distance between the point farthest from the preset origin and the preset origin; if the position of the vibration of the wind turbine tower barrel at any second preset cross-section exceeds the vibration trajectory circle, it is determined that the vibration state of the wind turbine tower barrel is abnormal.

[0025] Optionally, the system further includes: an inclination sensor, configured to acquire a first inclination angle and a second inclination angle of the wind turbine tower barrel in a balanced state, where the first inclination angle is the angle by which the bottom cross-section of the wind turbine tower barrel deviates from the vertical direction in the axial direction, and the second inclination angle is the angle by which the top cross-section of the wind turbine tower barrel deviates from the vertical direction in the axial direction; the controller is further configured to determine the offsets of the respective second preset cross-sections of the wind turbine tower barrel in the tower base plane according to the first inclination angle, the second inclination angle, and the height of the wind turbine tower barrel, and determine the center positions of the respective second preset cross-sections according to the position of the preset origin and the offsets of the respective second preset cross-sections in the tower base plane.

[0026] Optionally, the wind turbine tower barrel has a plurality of flange plates, the wind turbine tower barrel includes multiple sections of cylinders, adjacent cylinders are connected through the flange plates, and the lowermost cylinder of the wind turbine tower barrel is connected to the ground anchor through the flange plate; the system further includes: a bolt monitoring sensor, configured to acquire the pre-tightening forces of the bolts installed on each flange plate; the controller is further configured to determine whether each bolt is loose according to the comparison result between the pre-tightening force of the bolt and a preset pre-tightening force threshold.

[0027] Optionally, the strain sensor is an optical fiber sensor, and the controller is an optical fiber sensing analyzer.

[0028] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0029] In the solution of the embodiment of the present invention, strain results at a first preset cross-section of the wind turbine tower at multiple different heights are obtained through a strain sensor. Then, according to the strain results, the bending moments of the wind turbine tower at multiple first preset cross-sections are determined. By fitting the bending moments and heights, the distribution of the bending moment of the wind turbine tower with respect to height can be obtained. Since the section modulus resisting bending at different heights of the wind turbine tower can be determined according to the dimensions of the cross-sections of the wind turbine tower at different heights, the distribution of the stress of the wind turbine tower with respect to height can be obtained based on the distribution of the bending moment with respect to height and the section modulus resisting bending. Thus, the solution of the embodiment of the present invention obtains the distribution of the bending moment with respect to height by monitoring the strain results of multiple first cross-sections and then fitting, and then converts it into the distribution of the stress with respect to height. By such a method, the stress at any height of the wind turbine tower can be obtained, improving the accuracy of monitoring the stress of the wind turbine tower.

[0030] Furthermore, in the solution of the embodiment of the present invention, based on the distribution of the stress with respect to height, the number of times that the stress at different heights of the wind turbine tower changes from a first preset stress range to a second preset stress range and then changes from the second preset stress range to the first preset stress range within a first preset time range can be determined. By comparing the number with a preset threshold, the fatigue degree of the wind turbine tower at any height can be accurately and efficiently determined, so that the state of the wind turbine tower can be monitored more comprehensively.

[0031] Furthermore, in the solution of the embodiment of the present invention, while displaying a schematic diagram of the wind turbine tower on the user interface, a distribution diagram of the stress of the wind turbine tower with respect to height is also displayed. Since the abscissa of the distribution diagram is height and the ordinate is stress, the extending direction of the abscissa on the user interface is parallel to the height direction of the wind turbine tower on the user interface, and the distribution diagram is aligned with the schematic diagram. Therefore, the user can intuitively view the stress of the wind turbine tower at different heights on the user interface.

[0032] Furthermore, in the solution of the embodiment of the present invention, the vibration displacements at a second preset cross-section at different heights obtained through a vibration sensor are used to determine the vibration trajectories of the wind turbine tower at each second preset cross-section according to the vibration displacements and the center positions of each second preset cross-section. Then, the vibration trajectory circle of the wind turbine tower is determined based on multiple vibration trajectories. If the position where the wind turbine tower vibrates at any second preset cross-section exceeds the vibration trajectory circle, it is determined that the vibration state of the wind turbine tower is abnormal. Through this solution, whether there is an abnormality in the vibration state of the wind turbine tower can be accurately and intuitively monitored, further improving the comprehensiveness of the monitoring.

[0033] Furthermore, in the scheme of the embodiment of the present invention, the first inclination angle at the bottom section and the second inclination angle at the top section of the wind turbine tower are obtained by an inclination sensor, and then the offset of each second preset section in the tower base plane is determined according to the first inclination angle, the second inclination angle and the height of the wind turbine tower, and the center position of each second preset section is determined according to the offset, thereby determining the inclination posture of the wind turbine tower in a balanced state, thereby making the vibration trajectory of the wind turbine tower obtained by monitoring more accurate, thereby improving the accuracy of monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flow chart of a method for monitoring a wind turbine tower according to an embodiment of the present invention.

[0035] Figure 2 It is a partial schematic diagram of a wind turbine tower in an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of a user interface display in an embodiment of the present invention.

[0037] Figure 4 It is a flow chart of another method for monitoring a wind turbine tower according to an embodiment of the present invention.

[0038] Figure 5 It is an overall schematic diagram of a wind turbine tower in a balanced state according to an embodiment of the present invention.

[0039] Figure 6 It is a display schematic diagram of another user interface in an embodiment of the present invention.

[0040] Figure 7 It is a structural schematic diagram of a monitoring device for a wind turbine tower according to an embodiment of the present invention.

[0041] Figure 8 It is a structural schematic diagram of a wind turbine tower monitoring system according to an embodiment of the present invention.

[0042] Figure 9 This is a schematic diagram of the installation position of a sensor on a wind turbine tower according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] As described in the background art, there is an urgent need for a wind turbine tower monitoring method that can more accurately monitor the stress of the wind turbine tower.

[0044] Through research, the inventors of the present invention found that when monitoring the stress of a wind turbine tower in the prior art, only the stress at the position where the strain sensor is installed on the wind turbine tower can be monitored, and the stress at other heights of the wind turbine tower cannot be obtained. It can be understood that when the stress at the position where the strain sensor is installed on the wind turbine tower is normal, it does not mean that there are no problems such as overload anomalies at other positions of the wind turbine tower. Therefore, the accuracy of stress monitoring of the wind turbine tower in the prior art is poor.

[0045] To solve the above technical problems, an embodiment of the present invention provides a monitoring method for a wind turbine tower. In the solution of the embodiment of the present invention, strain results at a plurality of first preset cross-sections at different heights of the wind turbine tower are obtained through strain sensors, and then the bending moments at the plurality of first preset cross-sections of the wind turbine tower are determined according to the strain results. By fitting the bending moments and heights, the distribution of the bending moment of the wind turbine tower with respect to height can be obtained. Since the section modulus resisting bending at different heights of the wind turbine tower can be determined according to the dimensions of the cross-sections at different heights of the wind turbine tower, the distribution of the stress of the wind turbine tower with respect to height can be obtained according to the distribution of the bending moment with respect to height and the section modulus resisting bending. Thus, the solution of the embodiment of the present invention obtains the distribution of the bending moment with respect to height by monitoring the strain results of a plurality of first cross-sections and then fitting, and then converts it into the distribution of the stress with respect to height. By such a method, the stress at any height of the wind turbine tower can be obtained, improving the accuracy of stress monitoring of the wind turbine tower.

[0046] To make the above objects, features, and beneficial effects of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given with reference to the accompanying drawings.

[0047] Refer to Figure 1 , Figure 1 which is a schematic flowchart of a monitoring method for a wind turbine tower in an embodiment of the present invention. The method can be executed by a controller. The controller can be any appropriate terminal with data receiving and processing capabilities, such as a computer, a sensing analyzer, etc., but is not limited thereto. The controller can be disposed inside the wind turbine tower, and the controller can be coupled to each sensor disposed on the wind turbine tower; or, the controller is disposed outside the wind turbine tower and remotely coupled to the sensors disposed on the wind turbine tower, but is not limited thereto. The controller can be used to monitor one or more wind turbine towers. Specifically, the controller and the monitored wind turbine tower can be in a one-to-one correspondence, or the controller and the monitored wind turbine tower can be in a one-to-many relationship. Each controller is used to monitor the corresponding wind turbine tower, that is, the controller can be coupled to the sensors of the corresponding wind turbine tower. The wind turbine tower can be a part that plays a supporting role in a wind turbine generator set. In addition to the wind turbine tower, the wind turbine generator set can also include a plurality of blades disposed on the wind turbine tower, etc.

[0048] Figure 1 The shown monitoring method of the wind turbine tower can include the following steps:

[0049] Step S101: Obtain the strain results of the wind turbine tower at multiple first preset cross-sections through strain sensors, and calculate the bending moment at each first preset cross-section according to the strain results at each first preset cross-section. Different first preset cross-sections have different heights;

[0050] Step S102: Fit the bending moments of the wind turbine tower at multiple first preset cross-sections and the heights of each first preset cross-section to obtain the distribution of the bending moment with height;

[0051] Step S103: Obtain the distribution of the stress of the wind turbine tower with height according to the distribution of the bending moment with height and the flexural section modulus of the wind turbine tower; wherein, the flexural section modulus is determined according to the dimensions of the wind turbine tower at the cross-section.

[0052] In the specific implementation of step S101, the strain sensor can be a sensor for measuring the strain generated by the force deformation of an object. The strain sensor can be an optical fiber sensor, but is not limited thereto. The embodiments of the present invention do not impose any restrictions on the type of the strain sensor.

[0053] Further, the strain sensors can be arranged at multiple first preset cross-sections. Different first preset cross-sections have different heights. Thus, the strain results of the wind turbine tower at different heights can be obtained through the strain sensors. The first preset cross-section is a cross-section of the wind turbine tower. In order to facilitate the installation of components such as strain sensors and other types of sensors, appropriate installation components can be arranged at the wind turbine tower at the first preset cross-section for fixing various components.

[0054] See Figure 2 , Figure 2 shows a partial schematic diagram of a wind turbine tower in an embodiment of the present invention. The wind turbine tower can have multiple sections of cylinders 22. Adjacent two sections of cylinders 22 can be connected through a flange 21. The lowermost cylinder 22 of the wind turbine tower can be connected to the ground rivet through a flange 21 or other appropriate components. The uppermost cylinder 22 of the wind turbine tower can be connected to the wind turbine device above the wind turbine tower through a flange 21 or other appropriate components.

[0055] Further, the first preset cross-section can be arranged at a preset distance from the flange 21. Specifically, the first preset cross-section can be at a preset distance above the flange 21 or at a preset distance below the flange 21.

[0056] Preferably, the preset distance can be taken within the range of 100 mm to 500 mm. Specifically, since the cylinder 22 and the flange 21 are usually welded, stress anomalies are more likely to occur at the connection between the cylinder 22 and the flange 21. Also considering that there is usually a weld 24 between the cylinder 22 and the flange 21, strain sensors are arranged near the connection between the cylinder 22 and the flange 21 to monitor the stress at the position where overload anomalies are likely to occur.

[0057] In other words, the first preset section can be any section within the preset distance range 23 above the flange 21, and the preset distance range is 100 mm to 500 mm. Further, a layout section can be set at the position of the first preset section, and this layout section is used to install strain sensors and other components.

[0058] Continue to refer to Figure 1 , after obtaining the strain results of the wind turbine tower at each first preset section, the bending moment of the wind turbine tower at each first preset section can be calculated.

[0059] Specifically, according to the strain results of the wind turbine tower at each first preset section, the stress of the wind turbine tower at this first preset section can be calculated and determined. Specifically, the stress at the corresponding position can be calculated by using the strain results at each first preset section and the material properties of the wind turbine tower. Further, according to the dimensions of the cross-sections of the wind turbine tower at each first preset section, the flexural section modulus of the wind turbine tower at each first preset section can be calculated. Multiplying the stress of the wind turbine tower at each first preset section by the flexural section modulus of this first preset section, the bending moment of the wind turbine tower at this first preset section can be obtained.

[0060] In a non-limiting embodiment of the present invention, the sensing element of the strain sensor is a resistance strain gauge. Before the controller calculates the bending moment according to the strain results, temperature compensation can also be performed on the strain results at the first preset section.

[0061] Specifically, for the strain results at each first preset section, the temperature of the wind turbine tower at this first preset section can be obtained by a temperature sensor installed at this first preset section, and the strain results at this first preset section are temperature-compensated according to the temperature of the wind turbine tower at this first preset section. That is, the temperature measured by the temperature sensor located at the same first preset section as the strain sensor is used to perform temperature compensation on the strain results measured by the strain sensor.

[0062] More specifically, for a strain sensor using a resistance strain gauge as a sensing element, the measured strain result is obtained based on the resistance of the resistance strain gauge. Ideally, the change in resistance only depends on the force-induced deformation of the wind turbine tower. However, since the resistance of the resistance strain gauge is also significantly affected by temperature, it will cause the measured strain result of the strain sensor to be inaccurate, and temperature compensation needs to be performed on the strain result to obtain the strain result for calculating the bending moment. The method of temperature compensation can be various existing appropriate methods, such as the self-compensation method of the strain gauge, the line compensation method, etc., but is not limited thereto.

[0063] In the specific implementation of step S102, a model of bending moment and height can be constructed, and the parameters of the model can be solved based on the heights of multiple first preset cross-sections and the bending moments of the wind turbine tower at each first preset cross-section to obtain the distribution of the bending moment with height. The model can be any appropriate mathematical model describing the relationship between the bending moment and height.

[0064] In a non-limiting embodiment of the present invention, the model can be a polynomial model: M(H) = k1×H n +k2×H n-1 +k3×H n-2 +……+k n ×H + k n+1 , where M(H) is the bending moment of the wind turbine tower at height H, k_1, k_2, k_3... k n , k n+1 are the parameters of the polynomial model, and n is the highest degree of the polynomial model. Among them, n can be pre-configured, and n can be any positive integer. Preferably, the value of n is the same as the number of first preset cross-sections.

[0065] Furthermore, based on the heights and bending moments of the wind turbine tower at each first preset cross-section, the parameters in the above polynomial model can be solved. Substituting the solved parameters into the polynomial model can obtain the distribution of the bending moment of the wind turbine tower with height. The method for solving the parameters of the polynomial model can be any existing appropriate algorithm, such as the least squares method or the gradient descent method, etc., but is not limited thereto.

[0066] In the specific implementation of step S103, according to the dimensions of the cross-sections of the wind turbine tower at different heights, the flexural section modulus of the wind turbine tower at different heights can be calculated. That is, the height of the wind turbine tower is different, the dimensions of the cross-section where the wind turbine tower is located are different, and the flexural section modulus of the wind turbine tower is also different.

[0067] Preferably, the dimension may refer to the inner and outer diameters of the wind turbine tower at cross-sections at different heights. Specifically, for the inner and outer diameters of the wind turbine tower at cross-sections at different heights, the relationship between the inner and outer diameters and the height can be determined during the design process of the wind turbine tower. Since the moment of inertia can be calculated based on the inner and outer diameters of the wind turbine tower at cross-sections at different heights, the distribution of the moment of inertia of the wind turbine tower with height W(H) can be obtained, where W(H) is the moment of inertia of the wind turbine tower at height H.

[0068] Furthermore, based on the distribution of the bending moment of the wind turbine tower with height and the distribution of the moment of inertia with height, the distribution of the stress of the wind turbine tower with height can be obtained. Specifically, the stress of the wind turbine tower at any height is the result of dividing the bending moment of the wind turbine tower at that height by the moment of inertia at that height.

[0069] As described above, by obtaining the strain results at the first preset cross-sections of the wind turbine tower at multiple different heights through strain sensors, and then determining the bending moments of the wind turbine tower at the multiple first preset cross-sections based on the strain results, and fitting the bending moments and heights, the distribution of the bending moment of the wind turbine tower with height can be obtained. Since the moment of inertia at different heights of the wind turbine tower can be calculated based on the dimensions of the cross-sections at different heights of the wind turbine tower, the distribution of the stress of the wind turbine tower with height can be obtained based on the distribution of the bending moment with height and the moment of inertia. Therefore, in the solution of the embodiment of the present invention, the stress of the wind turbine tower at any height can be monitored, improving the accuracy of monitoring the wind turbine tower.

[0070] Furthermore, the number of times that the stress of the wind turbine tower at each height changes from the first preset stress range to the second preset stress range and then changes from the second preset stress range to the first preset stress range within the first preset time range can also be determined.

[0071] Among them, the first preset stress range and the second preset stress range can be pre-configured, for example, stored in the controller. The first preset stress range may include a first preset stress value, and the second preset stress range may include a second preset stress value. The first preset stress value and the second preset stress value may be opposite to each other, that is, the numerical values of the two stress values are equal but the directions are opposite. Further, the first preset stress value may be the stress threshold of the wind turbine tower in a certain direction, and the stress threshold can be determined according to the material properties of the wind turbine tower. The second preset stress value may be the stress threshold of the wind turbine tower in the opposite direction of the direction corresponding to the first preset stress value. Thus, the number of times can be used to describe the number of load cycles on the wind turbine tower.

[0072] Further, the first preset time range can be preconfigured, for example, stored in the controller. In a non-limiting embodiment of the present invention, the start time of the first preset time range can be the moment when the wind turbine tower is installed, or the moment when the strain sensor is installed on the wind turbine tower, but is not limited thereto.

[0073] Further, the number of times can be compared with a first preset threshold, and according to the comparison result, the fatigue degree of the wind turbine tower at different heights can be determined. When the number of times is greater than the first preset threshold, a first alarm message can be generated. The first alarm message can include: the height at which the number of times exceeds the first preset threshold, to indicate that the wind turbine tower is in an abnormal state of being relatively fatigued at this height position. The first preset threshold can be determined according to the fatigue limit of the wind turbine tower. Thus, the solution of the embodiment of the present invention can intuitively monitor the fatigue degree of any height of the wind turbine tower.

[0074] Further, in the solution of the embodiment of the present invention, a schematic diagram of the wind turbine tower and a distribution diagram of the stress of the wind turbine tower with height can also be displayed together on the user interface. The distribution diagram can be any diagram that can describe the distribution of stress with height. For example, it can be a bar chart, a curve chart, but is not limited thereto.

[0075] Reference Figure 3 , Figure 3 shows a schematic diagram of a user interface in an embodiment of the present invention.

[0076] Figure 3 The shown user interface displays a schematic diagram 31 of the wind turbine tower and a distribution diagram 32 of the stress of the wind turbine tower with height. Among them, the schematic diagram 31 of the wind turbine tower can be a view reflecting the height of the wind turbine tower. For example, it can be a side view of the wind turbine tower, but is not limited thereto. The abscissa of the distribution diagram 32 is height, and the ordinate is stress. The extending direction of the abscissa on the user interface is parallel to the height direction of the wind turbine tower on the user interface, that is, the abscissa direction is parallel to the height direction of the wind turbine tower.

[0077] Further, the distribution diagram 32 and the schematic diagram 31 are aligned. Specifically, the minimum value of the abscissa of the distribution diagram 32 can correspond to the bottom end of the wind turbine tower in the schematic diagram 31, and the maximum value of the abscissa can correspond to the top end of the wind turbine tower in the schematic diagram 31. Or, the minimum value of the abscissa of the distribution diagram 32 can correspond to the top end of the wind turbine tower in the schematic diagram 31, and the maximum value of the abscissa can correspond to the bottom end of the wind turbine tower in the schematic diagram 31.

[0078] Further, the allowable stress of the wind turbine tower can also be displayed on the user interface, where the allowable stress refers to the maximum stress value that the wind turbine tower is allowed to withstand. The user interface can also display the yield strength and / or the fracture stress. The yield strength refers to the stress value when the wind turbine tower exhibits a yield phenomenon, and the fracture stress refers to the stress value when the wind turbine tower exhibits a fracture phenomenon. The allowable stress, the yield strength, and the fracture stress can be pre-determined according to the material properties of the wind turbine tower and stored in the controller. It should be noted that the allowable stress is less than the yield strength, and the yield strength is less than the fracture stress.

[0079] Specifically, a line segment 33 for indicating the allowable stress, a line segment 34 for indicating the yield strength, and a line segment 35 for indicating the fracture stress can be displayed together in the distribution diagram 32. When the stress corresponding to any height in the schematic diagram 31 exceeds the allowable stress, a second alarm message can be issued, and the second alarm message can include: the height at which the stress exceeds the allowable stress.

[0080] Thus, in the solution of the embodiment of the present invention, the user can intuitively view the stress of the wind turbine tower at different heights on the user interface, and can also view whether the stress of the wind turbine tower at different heights is in a normal state.

[0081] Reference Figure 4 , Figure 4 is a schematic flowchart of another monitoring method for a wind turbine tower in an embodiment of the present invention. Figure 4 The monitoring method of the wind turbine tower shown can include the following steps:

[0082] Step S401: Obtain the vibration displacement of the wind turbine tower at at least one second preset cross-section within a second preset time range through a vibration sensor;

[0083] Step S402: Determine the center position of each second preset cross-section of the wind turbine tower in the balanced state;

[0084] Step S403: Determine the vibration trajectory of the wind turbine tower vibrating at the second preset cross-section according to the center position of each second preset cross-section and the vibration displacement of the wind turbine tower at the second preset cross-section within the second preset time range;

[0085] Step S404: Determine a vibration trajectory circle, where the center of the vibration trajectory circle is the preset origin, and the radius of the vibration trajectory circle is the distance between the point farthest from the preset origin and the preset origin;

[0086] Step S405: If the vibration position of the wind turbine tower at any second preset cross-section exceeds the vibration trajectory circle, determine that the vibration state of the wind turbine tower is abnormal.

[0087] In the specific implementation of step S401, the vibration sensor may be a sensor for measuring the vibration state of an object. The vibration sensor may be an optical fiber sensor, but is not limited thereto. The vibration sensor may be disposed at at least one second preset cross-section, and the second preset cross-section is a cross-section of the wind turbine tower barrel. Different second preset cross-sections have different heights. The second preset cross-section may be selected according to the vibration characteristics of the wind turbine tower barrel. Usually, the height where the vibration link of the wind turbine tower barrel is relatively weak or where fatigue is likely to occur in the wind turbine tower barrel may be selected. For example, the top cross-section of the wind turbine tower barrel and / or the cross-section at the middle value of the height of the wind turbine tower barrel, where the middle value is one-half of the height of the wind turbine tower barrel. In a non-limiting embodiment of the present invention, the second preset cross-section may be selected from the first preset cross-section. In other words, the vibration sensor may be installed at the first preset cross-section where the strain sensor is located, which can reduce the construction amount. More descriptions about the second preset cross-section may refer to the relevant descriptions of the first preset cross-section, and will not be elaborated here.

[0088] Thus, the vibration displacement of the wind turbine tower barrel at different heights within the second preset time range can be obtained through the vibration sensor. The vibration displacement refers to the displacement of the wind turbine tower barrel relative to its position in the equilibrium state during vibration. It should be noted that the vibration displacement may also refer to the displacement of any point on the wind turbine tower barrel relative to the position of this point on the wind turbine tower barrel in the equilibrium state during vibration. More specifically, the vibration displacement may also be the displacement of the center of the circle of any second preset cross-section of the wind turbine tower barrel relative to the position of the center of the circle of this cross-section on the wind turbine tower barrel in the equilibrium state.

[0089] Among them, the second preset time range may be set on-site, such as received by the controller from the outside; or, the second preset time range may also be pre-configured, such as pre-stored in the controller. The setting of the second preset time range may be determined according to actual requirements. For example, considering that the differences in wind direction and wind force in different seasons are relatively obvious, the second preset time range may be set according to the season, and thus the vibration trajectory of the wind turbine tower barrel under the action of wind loads in different seasons can be further obtained, but is not limited thereto.

[0090] In the specific implementation of step S402, the center position of each second preset cross-section of the wind turbine tower barrel in the equilibrium state can be determined. Among them, the center position of the second preset cross-section refers to the position where the center of the second preset cross-section is projected onto the tower base plane, and the tower base plane may be the plane where the bottom cross-section is located when the wind turbine tower barrel is installed.

[0091] Specifically, the center positions of each second preset cross-section of the wind turbine tower can be the same as the center position of the bottom cross-section of the wind turbine tower in the balanced state. The bottom cross-section can coincide with the tower foundation plane. That is, when the center position of the second preset cross-section is projected downward onto the bottom cross-section, it coincides with the center position of the bottom cross-section of the preset origin in the tower foundation plane, but it is not limited to this. Wherein, the preset origin refers to the center of the bottom cross-section when the bottom cross-section coincides with the tower foundation plane.

[0092] In a non-limiting embodiment of the present invention, considering that after a period of use of the wind turbine tower, it may be inclined and bent due to reasons such as overload, material deformation, and foundation settlement. The bottom cross-section of the wind turbine tower in the balanced state may not coincide with the tower foundation plane, and each second preset cross-section may no longer be parallel to the bottom cross-section of the wind turbine tower. At this time, the center positions of each second preset cross-section can be determined by the inclination angle measured by an inclination sensor (also known as an inclinometer) and the height of the wind turbine tower.

[0093] Reference Figure 5 , Figure 5 shows an overall schematic diagram of a wind turbine tower. Figure 5 The shown wind turbine tower has a certain inclination and bending.

[0094] Furthermore, the first inclination angle 53 can be obtained by the inclination sensor installed at the first preset cross-section with the lowest height. The first inclination angle 53 refers to the angle at which the bottom cross-section 52 of the wind turbine tower deviates from the vertical direction in the axial direction. The second inclination angle 54 can also be obtained by the inclination sensor installed at the first preset cross-section with the highest height. The second inclination angle 54 can refer to the angle at which the top cross-section 51 of the wind turbine tower deviates from the vertical direction in the axial direction. Wherein, the vertical direction refers to the direction perpendicular to the tower foundation plane.

[0095] Furthermore, according to the first inclination angle 53, the second inclination angle 54, and the height of the wind turbine tower, the angle at which each second preset cross-section deviates from the vertical direction in the axial direction can be determined. It should be noted that the height of the wind turbine tower can refer to the height of the top cross-section 51 relative to the tower foundation plane when the wind turbine tower is installed.

[0096] Furthermore, the offset of each second preset cross-section in the tower foundation plane can be determined according to the height of each second preset cross-section and the angle at which the second preset cross-section deviates from the vertical direction in the axial direction. The offset of each second preset cross-section in the tower foundation plane can also be regarded as the offset of the center of the second preset cross-section in the tower foundation plane. The height of the second preset cross-section can refer to the height of each second preset cross-section relative to the above-mentioned tower foundation plane when the wind turbine tower is installed.

[0097] Further, based on the position of the preset center in the tower base plane and the offsets of each second preset section in the tower base plane, the positions of the centers of each second preset section of the tilted and bent wind turbine tower in the tower base plane in the balanced state can be determined. Among them, the position of the preset center is the position of the center of the bottom section when the wind turbine tower is installed.

[0098] Continue to refer to Figure 4 , in the specific implementation of step S403, the vibration sensor can obtain the displacements of each second preset section when the wind turbine tower vibrates. Therefore, according to the center position of each second preset section and the displacement of this second preset section, the position of the center of this second preset section of the wind turbine tower in the tower base plane when the wind turbine tower vibrates can be determined.

[0099] Further, for each second preset section, by obtaining the vibration displacements of the wind turbine tower at the second preset section at multiple moments within the second preset time range, multiple center positions of the second preset section of the wind turbine tower when it vibrates can be determined. Further, according to the multiple center positions of the second preset section at different moments, the vibration trajectory of the center of the second preset section in the tower base plane within the second preset time range can be fitted. This vibration trajectory can be regarded as the vibration trajectory of the wind turbine tower at the second preset section within the second preset time range.

[0100] Thus, in the solution of the embodiment of the present invention, the first inclination angle at the bottom section of the wind turbine tower and the second inclination angle at the top section are obtained through the inclination sensor, and then the offsets of each second preset section in the tower base plane are determined according to the first inclination angle, the second inclination angle and the height of the wind turbine tower, and the center positions of each second preset section are determined according to the offsets. Thus, the inclined posture of the wind turbine tower in the balanced state can be determined, so that the vibration trajectory of the monitored wind turbine tower is more accurate, improving the accuracy of the monitoring.

[0101] In the specific implementation of step S404, a vibration trajectory circle can be determined according to the vibration trajectories at at least one second preset section obtained in step S403. The vibration trajectory circle refers to the circle with the smallest radius that can contain the vibration trajectories at at least one second preset section.

[0102] Specifically, determine the point farthest from the preset origin on the vibration trajectory at at least one second preset section, and use the distance between the point farthest from the preset origin and the preset origin as the radius, with the preset origin as the center, to obtain the vibration trajectory circle. The vibration trajectory circle can be used to indicate the positions of the centers of each second preset section in the tower base plane when the vibration state of the wind turbine tower is normal.

[0103] In the specific implementation of step S405, since the vibration displacement of the wind turbine tower can be monitored by the vibration sensor, and according to the center positions of each second preset cross-section of the wind turbine tower in the balanced state, the controller can monitor the position of the center of the second preset cross-section of the wind turbine tower in the tower base plane during vibration. More specifically, the position of the center of the second preset cross-section in the tower base plane can be used to indicate the vibration position of the wind turbine tower at this second preset cross-section.

[0104] Further, when the center position of any second preset cross-section exceeds the vibration trajectory circle during the vibration of the wind turbine tower, it can be determined that the vibration state of the wind turbine tower is abnormal.

[0105] Further, in the solution of the embodiment of the present invention, the vibration trajectories and the vibration trajectory circle of each second preset cross-section during the vibration of the wind turbine tower can also be displayed on the user interface.

[0106] Reference Figure 6 , Figure 6 shows a schematic diagram of another user interface in the embodiment of the present invention.

[0107] Figure 6 The shown user interface displays the first vibration trajectory 65 and the second vibration trajectory 66. The first vibration trajectory 65 refers to the vibration trajectory of the wind turbine tower at the second preset cross-section corresponding to the center position 62 in the balanced state. Among them, the second preset cross-section corresponding to the center position 62 in the balanced state can be the top cross-section of the wind turbine tower.

[0108] Further, the second vibration trajectory 66 refers to the vibration trajectory of the wind turbine tower at the second preset cross-section corresponding to the center position 63 in the balanced state. The second preset cross-section corresponding to the center position 63 in the balanced state can be the cross-section with the intermediate value of the height, where the intermediate value is one-half of the height of the wind turbine tower. It should be noted that the embodiment of the present invention does not impose any restrictions on the heights of the second preset cross-sections corresponding to the first vibration trajectory 65 and the second vibration trajectory 66 respectively.

[0109] Further, the center 64 of the vibration trajectory circle 61 is the position of the center of the bottom cross-section of the wind turbine tower in the tower base plane during installation, and the vibration trajectory circle can be determined by the method shown in Figure 5 shown.

[0110] Further, the vibration displacement of the wind turbine tower at the second preset cross-section during vibration can be obtained regularly. Whenever new vibration displacement is obtained, the vibration trajectory can be updated. Thus, the user can intuitively judge whether the vibration state of the wind turbine tower is abnormal according to the relative positions of the vibration trajectory and the vibration trajectory circle displayed on the user interface, making the monitoring process more intuitive.

[0111] In a non-limiting embodiment of the present invention, the vibration sensor may be an acceleration sensor. The controller may also obtain the vibration frequencies of the wind turbine tower at each second preset cross-section through the acceleration sensor, and determine the natural frequency of the wind turbine tower at the second preset cross-section according to the vibration frequency at each second preset cross-section. The controller may pre-store the preset natural frequency of the wind turbine tower.

[0112] Further, calculate the difference between the natural frequency of the wind turbine tower at each second preset cross-section and the preset natural frequency at the second preset cross-section. If the absolute value of the difference exceeds the second preset threshold, the controller may determine that there is damage to the wind turbine tower at the second preset cross-section.

[0113] Further, the pre-tightening force of the bolts installed on each flange may also be obtained through a bolt monitoring sensor.

[0114] Specifically, the bolt monitoring sensor may be fixed to the bolt by a thread and can achieve synchronous deformation with the bolt. The bolt monitoring sensor may include a Micro-Electro-Mechanical System (MEMS) fiber optic pressure sensor, and the MEMS fiber optic pressure sensor may measure pressure, and thus the pre-tightening force of the bolt may be obtained.

[0115] Therefore, the solution of the embodiment of the present invention can monitor the pre-tightening force of each bolt. During the assembly process of the bolts, by monitoring the pre-tightening force of each bolt, it can be ensured that the multiple bolts are evenly stressed during assembly, thereby realizing the digital technology of bolt assembly.

[0116] Further, during the operation of the wind turbine tower, the comparison result of the pre-tightening force of each bolt with the preset pre-tightening force threshold may be used to determine whether each bolt is loose. If the pre-tightening force of any bolt is less than the preset pre-tightening force threshold, it may be determined that the bolt is loose.

[0117] As described above, the solution of the embodiment of the present invention can comprehensively monitor the wind turbine tower through various sensors such as strain sensors, temperature sensors, vibration sensors, tilt sensors, and bolt detection sensors, so as to obtain the status information of the tower in real time and in all directions.

[0118] Reference Figure 7 , Figure 7 is a schematic structural diagram of a monitoring device for a wind turbine tower in an embodiment of the present invention. The monitoring device for the wind turbine tower may include:

[0119] The first acquisition module 71 is configured to acquire the strain results of the wind turbine tower at multiple first preset cross-sections through strain sensors, and calculate the bending moment at each first preset cross-section according to the strain results at each first preset cross-section. Different first preset cross-sections have different heights;

[0120] The fitting module 72 is configured to fit the bending moments of the wind turbine tower at multiple first preset cross-sections and the heights of each first preset cross-section to obtain the distribution of the bending moment with height;

[0121] The stress calculation module 73 is configured to obtain the distribution of the stress of the wind turbine tower with height according to the distribution of the bending moment with height and the anti-bending section modulus of the wind turbine tower at different heights; wherein, the anti-bending section modulus is determined according to the dimensions of the wind turbine tower at the cross-section.

[0122] For the principle, working mode and beneficial effects of the monitoring device of the wind turbine tower in the embodiments of the present invention, please refer to the relevant descriptions of the monitoring method of the wind turbine tower above, and will not be repeated here.

[0123] Reference Figure 8 [[ID=…]] Figure 8 FIG. is a schematic structural diagram of a monitoring system of a wind turbine tower in an embodiment of the present invention. The monitoring system of the wind turbine tower may include:

[0124] The strain sensor 81 is configured to acquire the strain results of the wind turbine tower at multiple first preset cross-sections, and different first preset cross-sections have different heights;

[0125] The controller 80 is configured to calculate the bending moment at each first preset cross-section according to the strain results at each first preset cross-section, fit the bending moments of the wind turbine tower at multiple first preset cross-sections and the heights of each first preset cross-section to obtain the distribution of the bending moment with height, and obtain the distribution of the stress of the wind turbine tower with height according to the distribution of the bending moment with height and the anti-bending section modulus of the wind turbine tower; wherein, the anti-bending section modulus is determined according to the dimensions of the wind turbine tower at the cross-section.

[0126] Wherein, the controller may be coupled to a memory storing a computer program. The controller may read the computer program in the memory and execute the steps of the above-mentioned monitoring method of the wind turbine tower by running the computer program. It should be noted that the controller may be a processor independent of the memory, or a terminal integrated with a memory and a processor, but is not limited thereto.

[0127] ​Further, the monitoring system of the wind turbine tower can further include: a temperature sensor 82 for obtaining the temperature of the wind turbine tower at a plurality of first preset cross-sections; the controller 80 is further configured to perform temperature compensation on the strain result at each first preset cross-section according to the temperature of the wind turbine tower at the first preset cross-section.

[0128] Further, the monitoring system of the wind turbine tower can further include: a vibration sensor 83 for obtaining the vibration displacement of the wind turbine tower at at least one second preset cross-section within a second preset time range; the controller 80 is further configured to determine the center position of each second preset cross-section of the wind turbine tower in a balanced state; according to the center position of each second preset cross-section and the vibration displacement of the wind turbine tower at the second preset cross-section within the second preset time range, determine the vibration trajectory of the wind turbine tower at the second preset cross-section, and determine the point farthest from a preset origin on the vibration trajectory at the at least one second preset cross-section, the position of the preset origin is the center position of the bottom cross-section when the wind turbine tower is installed, determine the vibration trajectory circle, the center of the vibration trajectory circle is the preset origin, and the radius of the vibration trajectory circle is the distance between the point farthest from the preset origin and the preset origin; if the vibration position of the wind turbine tower at any second preset cross-section exceeds the vibration trajectory circle, it is determined that the vibration state of the wind turbine tower is abnormal.

[0129] Further, the monitoring system of the wind turbine tower can further include: an inclination sensor 84 for obtaining a first inclination angle and a second inclination angle of the wind turbine tower in a balanced state, the first inclination angle is the angle at which the bottom cross-section of the wind turbine tower deviates from the vertical direction in the axial direction, and the second inclination angle is the angle at which the top cross-section of the wind turbine tower deviates from the vertical direction in the axial direction; the controller 80 can further be configured to determine the offset of each second preset cross-section in the tower base plane according to the first inclination angle, the second inclination angle and the height of the wind turbine tower, and determine the center position of each second preset cross-section according to the position of the preset origin and the offset of each second preset cross-section in the tower base plane.

[0130] Further, the monitoring system of the wind turbine tower can further include: a bolt monitoring sensor 85 for obtaining the pre-tightening force of the bolts installed on each flange; the controller 80 can further be configured to determine whether each bolt is loose according to the comparison result between the pre-tightening force of the bolt and a preset pre-tightening force threshold.

[0131] Regarding the principle, structure, working mode and beneficial effects of the monitoring system of the wind turbine tower in the embodiments of the present invention, please refer to the relevant descriptions of the monitoring method of the wind turbine tower above, and will not be elaborated here.

[0132] Reference Figure 9 , Figure 9It is a schematic diagram of the installation position of a sensor on a wind turbine tower in an embodiment of the present invention.

[0133] Figure 9 The shown wind turbine tower includes a plurality of first preset cross-sections 91, each first preset cross-section is located above or below an adjacent flange 92, and one or more sensors 93 can be provided at each first preset cross-section 91. The sensors can be strain sensors, temperature sensors, vibration sensors, inclination sensors, bolt monitoring sensors, etc., but are not limited thereto. Further, a layout section 94 can be provided at the position of the first preset cross-section 93, and the layout section 94 is used to install one or more sensors 93.

[0134] Specifically, a strain sensor, a temperature sensor, and a bolt monitoring sensor can be installed at each first preset cross-section 91, an inclination sensor can be installed at the first preset cross-section 93 with the minimum height and the first preset cross-section 93 with the maximum height, a vibration sensor can also be installed at the first preset cross-section 93 with the maximum height, and a vibration sensor can also be installed at the first preset cross-section 93 with the intermediate value of the height, where the intermediate value is the intermediate value of the height of the first preset cross-section. The vibration sensor can be an acceleration sensor.

[0135] Further, the above-mentioned sensor 93 can be an optical fiber sensor, which can avoid disadvantages such as lightning induction that electrical sensors may cause. Or, the above-mentioned sensor 93 can also be other appropriate types of sensors.

[0136] The embodiment of the present invention also discloses a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and the computer program can execute the steps of the above method when running. The storage medium can include ROM, RAM, a magnetic disk, or an optical disc, etc. The storage medium can also include non-volatile memory or non-transitory memory, etc.

[0137] Among them, the processor can be a central processing unit (CPU for short), and this processor can also be other general-purpose processors, a digital signal processor (DSP for short), an application specific integrated circuit (ASIC for short), a field programmable gate array (FPGA for short), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or this processor can also be any conventional processor, etc.

[0138] It should be noted that the controller may further include a memory, which may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of random access memory (RAM) are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM).

[0139] The above embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired or wireless manner. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more collections of available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media. The semiconductor media can be a solid-state drive.

[0140] It should be understood that in various embodiments of the present application, the sequence numbers of the above processes do not indicate the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0141] In several embodiments provided in the present application, it should be understood that the disclosed methods, devices, and systems can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for example, the division of the units is only a logical function division, and there can be other division methods in actual implementation; for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings, direct couplings, or communication connections between each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0142] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0143] In addition, in each embodiment of the present invention, each functional unit can be integrated into a processing unit, or each unit can be physically separate, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware, or in the form of a hardware plus software functional unit.

[0144] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit stored in a storage medium includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute some steps of the methods described in the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM for short), random access memories (RAM for short), magnetic disks, or optical discs that can store program codes.

[0145] It should be understood that the term "and / or" in this article is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article indicates that the associated objects before and after are in an "or" relationship.

[0146] The term "a plurality of" appearing in the embodiments of the present application refers to two or more.

[0147] The descriptions such as first and second appearing in the embodiments of the present application are only for the purpose of illustration and distinguishing the described objects, without any order, nor do they represent special limitations on the number of devices in the embodiments of the present application, and cannot constitute any limitation to the embodiments of the present application.

[0148] The term "connection" appearing in the embodiments of the present application refers to various connection methods such as direct connection or indirect connection to achieve communication between devices, and the embodiments of the present application do not make any limitations on this.

[0149] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A monitoring method for a wind turbine tower, characterized in that, The method includes: Obtaining strain results of the wind turbine tower barrel at multiple first preset cross-sections through a strain sensor, and calculating the bending moment at each first preset cross-section according to the strain results at each first preset cross-section, where different first preset cross-sections have different heights; Fitting the bending moments at multiple first preset cross-sections of the wind turbine tower barrel and the heights of each first preset cross-section to obtain the distribution of the bending moment with height; Obtaining the distribution of the stress of the wind turbine tower barrel with height according to the distribution of the bending moment with height and the flexural section modulus of the wind turbine tower barrel; Wherein, the flexural section modulus is determined according to the dimensions of the wind turbine tower barrel at the cross-section; Obtaining the vibration displacement of the wind turbine tower barrel at at least one second preset cross-section within a second preset time range through a vibration sensor; Determining the center position of each second preset cross-section of the wind turbine tower barrel in the balanced state; Determining the vibration trajectory of the wind turbine tower barrel vibrating at the second preset cross-section according to the center position of each second preset cross-section and the vibration displacement of the wind turbine tower barrel at the second preset cross-section within the second preset time range; Determining the point farthest from a preset origin on the vibration trajectory at the at least one second preset cross-section, where the position of the preset origin is the center position of the bottom cross-section of the wind turbine tower barrel during installation; Determining a vibration trajectory circle, where the center of the vibration trajectory circle is the preset origin, and the radius of the vibration trajectory circle is the distance between the point farthest from the preset origin and the preset origin; If the position of the wind turbine tower barrel vibrating at any second preset cross-section exceeds the vibration trajectory circle, determining that the vibration state of the wind turbine tower barrel is abnormal.

2. The monitoring method of the wind turbine tower according to claim 1, characterized in that, Fitting the bending moment of the wind turbine tower at multiple first preset cross-sections and the height of each first preset cross-section includes: constructing a polynomial model M(H) = k1×H n + k2×H n-1 + k3×H n-2 + …… + k n ×H + k n+1 , where M(H) is the bending moment of the wind turbine tower at height H, k1, k2, k3 …… k n , k n+1 are the parameters of the polynomial model, and n is the highest degree of the polynomial model; Solving the parameters of the polynomial model according to the bending moments at multiple first preset cross-sections of the wind turbine tower barrel and the heights of each first preset cross-section to obtain the distribution of the bending moment with height.

3. The monitoring method of the wind turbine tower according to claim 1, characterized in that, Before calculating and determining the bending moment at each first preset cross-section according to the strain results at each first preset cross-section, the method further includes: Obtaining the temperature of the wind turbine tower barrel at the multiple first preset cross-sections through a temperature sensor; Performing temperature compensation on the strain results at each first preset cross-section according to the temperature of the wind turbine tower barrel at each first preset cross-section.

4. The monitoring method of the wind turbine tower according to claim 1, wherein The method further includes: Determining the number of times the stress of the wind turbine tower barrel at different heights changes from a first preset stress range to a second preset stress range and from the second preset stress range to the first preset stress range within a first preset time range; Comparing the number of times with a first preset threshold to determine the fatigue degree of the wind turbine tower barrel at different heights.

5. The monitoring method of the wind turbine tower according to claim 1, characterized in that, The method further includes: Displaying a schematic diagram of the wind turbine tower barrel on a user interface; Displaying the distribution diagram of the stress of the wind turbine tower barrel with height on the user interface together; Wherein, the abscissa of the distribution diagram is height, the ordinate is stress, the extending direction of the abscissa on the user interface is parallel to the height direction of the wind turbine tower barrel on the user interface, and the distribution diagram is aligned with the schematic diagram.

6. The monitoring method of the wind turbine tower according to claim 1, characterized in that, [[ID= Obtain a first inclination angle and a second inclination angle of the wind turbine tower barrel in a balanced state through an inclination sensor, where the first inclination angle is the angle at which the bottom cross-section of the wind turbine tower barrel deviates from the vertical direction axially, and the second inclination angle is the angle at which the top cross-section of the wind turbine tower barrel deviates from the vertical direction axially; Determine the offset of each second preset cross-section of the wind turbine tower barrel in the tower base plane in the balanced state according to the first inclination angle, the second inclination angle, and the height of the wind turbine tower barrel; Determine the center position of each second preset cross-section according to the position of the preset origin and the offset of each second preset cross-section in the tower base plane.

7. The monitoring method of the wind turbine tower according to claim 1, characterized in that The at least one second preset cross-section includes: a first preset cross-section with the maximum height, and a first preset cross-section with a middle value of the height, where the middle value is the middle value of the heights of the multiple first preset cross-sections.

8. The monitoring method of the wind turbine tower according to claim 1, characterized in that, The method further includes: Obtain the vibration frequencies of the wind turbine tower barrel at at least one second preset cross-section at different times through an acceleration sensor; Determine the natural frequency of the wind turbine tower barrel at the second preset cross-section according to the frequency at each second preset cross-section; Calculate the difference between the natural frequency of the wind turbine tower barrel at each second preset cross-section and the preset natural frequency. If the absolute value of the difference is greater than a second preset threshold, it is determined that the vibration state of the wind turbine tower barrel is abnormal.

9. The monitoring method of the fan tower according to claim 1, characterized in that The wind turbine tower barrel has multiple flange plates. The wind turbine tower barrel includes multiple sections of cylinders, and adjacent cylinders are connected through the flange plates. The lowermost cylinder of the wind turbine tower barrel is connected to the ground rivet through the flange plate, and the first preset cross-section is set at a preset distance from each flange plate.

10. The monitoring method of the wind turbine tower according to claim 9, characterized in that, The strain sensors are installed at the multiple first preset cross-sections.

11. The monitoring method of the wind turbine tower according to claim 9, wherein, The preset distance is 100 millimeters to 500 millimeters.

12. The monitoring method of the wind turbine tower according to claim 9, characterized in that, The method further includes: Obtain the pre-tightening force of the bolts installed on each flange plate through a bolt monitoring sensor, and judge whether each bolt is loose according to the comparison result of the pre-tightening force of each bolt and the preset pre-tightening force threshold.

13. A monitoring device for a wind turbine tower, characterized in that, The device includes: A first acquisition module, configured to obtain the strain results of the wind turbine tower barrel at multiple first preset cross-sections through strain sensors, and calculate the bending moment at the first preset cross-section according to the strain results at each first preset cross-section. Different first preset cross-sections have different heights; A fitting module, configured to fit the bending moments of the wind turbine tower barrel at multiple first preset cross-sections and the heights of the respective first preset cross-sections to obtain the distribution of the bending moment with height; A stress calculation module, configured to obtain the distribution of the stress of the wind turbine tower barrel with height according to the distribution of the bending moment with height and the anti-bending section modulus of the wind turbine tower barrel; Wherein, the anti-bending section modulus is determined according to the dimensions of the wind turbine tower barrel at the cross-section; Obtain the vibration displacement of the wind turbine tower barrel at at least one second preset cross-section within a second preset time range through a vibration sensor; Determine the center position of each second preset cross-section of the wind turbine tower barrel in the balanced state; Determine the vibration trajectory of the wind turbine tower barrel vibrating at the second preset cross-section according to the center position of each second preset cross-section and the vibration displacement of the wind turbine tower barrel at the second preset cross-section within the second preset time range; Determine the point on the vibration trajectory at the at least one second preset cross-section that is farthest from the preset origin, where the position of the preset origin is the center position of the bottom cross-section when the wind turbine tower is installed; Determine the vibration trajectory circle, where the center of the vibration trajectory circle is the preset origin, and the radius of the vibration trajectory circle is the distance between the point farthest from the preset origin and the preset origin; If the vibration position of the wind turbine tower at any second preset cross-section exceeds the vibration trajectory circle, determine that the vibration state of the wind turbine tower is abnormal.

14. A storage medium having a computer program stored thereon, characterized in that, When the computer program is run by a processor, execute the steps of the monitoring method of the wind turbine tower according to any one of claims 1 to 12.

15. A monitoring system for a wind turbine tower, characterized in that, The system includes: A strain sensor for obtaining strain results of the wind turbine tower at a plurality of first preset cross-sections, where different first preset cross-sections have different heights; A controller for calculating the bending moment at each first preset cross-section according to the strain result at each first preset cross-section, fitting the bending moments at the plurality of first preset cross-sections of the wind turbine tower and the heights of the respective first preset cross-sections to obtain the distribution of the bending moment with height, and obtaining the distribution of the stress of the wind turbine tower with height according to the distribution of the bending moment with height and the section modulus of the wind turbine tower in bending; Wherein, the section modulus in bending is determined according to the dimensions of the wind turbine tower at the cross-section; A vibration sensor for obtaining the vibration displacement of the wind turbine tower at at least one second preset cross-section within a second preset time range; The controller is further configured to determine the center position of each second preset cross-section of the wind turbine tower in the balanced state; determine the vibration trajectory of the wind turbine tower at the second preset cross-section according to the center position of each second preset cross-section and the vibration displacement of the wind turbine tower at the second preset cross-section within the second preset time range, determine the point on the vibration trajectory at the at least one second preset cross-section that is farthest from the preset origin, where the position of the preset origin is the center position of the bottom cross-section when the wind turbine tower is installed, determine the vibration trajectory circle, where the center of the vibration trajectory circle is the preset origin, and the radius of the vibration trajectory circle is the distance between the point farthest from the preset origin and the preset origin; If the vibration position of the wind turbine tower at any second preset cross-section exceeds the vibration trajectory circle, determine that the vibration state of the wind turbine tower is abnormal.

16. The monitoring system of the wind turbine tower according to claim 15, characterized in that, The system further includes: A temperature sensor for obtaining the temperature of the wind turbine tower at a plurality of first preset cross-sections; The controller is further configured to perform temperature compensation on the strain result at each first preset cross-section according to the temperature of the wind turbine tower at each first preset cross-section.

17. The monitoring system of the fan tower according to claim 15, characterized in that, The system further includes: An inclination sensor for obtaining a first inclination angle and a second inclination angle of the wind turbine tower in the balanced state, where the first inclination angle is the angle by which the bottom cross-section of the wind turbine tower deviates from the vertical direction in the axial direction, and the second inclination angle is the angle by which the top cross-section of the wind turbine tower deviates from the vertical direction in the axial direction; The controller is further configured to determine the offsets of each second preset cross-section of the wind turbine tower in the tower base plane in a balanced state according to the first inclination angle, the second inclination angle, and the height of the wind turbine tower, and determine the center positions of each second preset cross-section according to the position of the preset origin and the offsets of each second preset cross-section in the tower base plane.

18. The monitoring system of the wind turbine tower according to claim 15, characterized in that, The wind turbine tower has a plurality of flange plates. The wind turbine tower includes multiple sections of cylinders, and adjacent cylinders are connected by the flange plates. The lowermost cylinder of the wind turbine tower is connected to the ground anchor by the flange plate. The system further includes: A bolt monitoring sensor for obtaining the pre-tightening force of the bolts installed on each flange plate; The controller is further configured to determine whether each bolt is loose based on the comparison result between the pre-tightening force of the bolt and a preset pre-tightening force threshold.

19. The monitoring system for a wind turbine tower according to claim 15, characterized in that, The strain sensor is an optical fiber sensor, and the controller is an optical fiber sensing analyzer.

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