A wind turbine tower load monitoring system and method

Abstract

The application discloses a wind turbine tower load monitoring system and method, which is used for measuring a concrete tower load and comprises a support assembly, a strain measuring element, a strain measuring bridge and a load output module. The support assembly is installed on the inner side of the concrete tower, and the support assembly at least comprises a measuring plate with a smooth surface. The strain measuring element is installed on the measuring plate and is used for measuring the strain of the concrete tower. The strain measuring element is included in the strain measuring bridge, and the strain measuring bridge outputs a measuring electric signal according to the strain of the concrete tower measured by the strain measuring element. The load output module is used for acquiring the measuring electric signal, and calculating the load of the concrete tower according to the measuring electric signal and linear load parameters. In the application, the strain measuring element is installed on the smooth measuring plate, so that the strain measuring element and the measuring plate are firmly connected and are suitable for long-term monitoring of the load of the concrete tower.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind power generation technology, and in particular to a wind turbine tower load monitoring system and method. BACKGROUND

[0002] In recent years, the increasing demand for single machine capacity of wind turbine has led to the increasing height of the tower. In order to improve the operation safety of the wind turbine, it is necessary to monitor the tower of the wind turbine for a long time. The tower monitoring involves the measurement of the tower load. The measurement technology of the load of the steel tower part included in the tower has been mature, while the measurement technology of the load of the concrete tower part included in the tower needs to be improved.

[0003] At present, the concrete tower load can be inferred from the measured steel tower load. However, the inferred concrete tower load is inaccurate. The tower strain can also be obtained by embedding a measuring rod device with strain gauges in the concrete tower, and then the concrete tower load can be directly obtained from the tower strain. However, once the measuring rod device embedded in the concrete tower is damaged, it cannot be repaired.

[0004] In addition, the strain of the concrete tower can be obtained by directly pasting strain gauges on the concrete tower, and then the concrete tower load can be directly obtained from the strain of the concrete tower. When the strain gauges are damaged or fail, the strain gauges can be directly replaced. However, the strain gauges directly pasted on the concrete tower are prone to serious failure in a short period of time, resulting in frequent replacement of the strain gauges. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a wind turbine tower load monitoring system and method, which can be used for long-term measurement of the concrete tower load and has the characteristics of easy repair after damage and accurate load measurement.

[0006] In order to achieve the above purpose, the technical scheme provided by the embodiments of the present application is as follows:

[0007] The present application provides a wind turbine tower load monitoring system, which is used for measuring the concrete tower load and includes a support assembly, a strain measurement element, a strain measurement bridge and a load output module.

[0008] The support assembly is installed on the inner side of the concrete tower, and the support assembly at least includes a measurement plate with a smooth surface.

[0009] The strain measurement element is installed on the measurement plate, and the strain measurement element is used for measuring the strain of the concrete tower.

[0010] The strain measurement bridge includes a strain measurement element; the strain measurement bridge outputs a measurement electric signal according to the strain of the concrete tower measured by the strain measurement element; the concrete tower load and the measurement electric signal are in a linear relationship;

[0011] The load output module is configured to acquire the measurement electric signal, and calculate the concrete tower load according to the measurement electric signal and a linear load parameter.

[0012] Optionally, the support assembly includes the measurement plate with a smooth surface, a first connecting component, and a second connecting component.

[0013] One end of the first connecting component and one end of the measurement plate are fixedly connected, and one end of the second connecting component and the other end of the measurement plate are fixedly connected; the other end of the first connecting component and the other end of the second connecting component are both embedded inside the concrete tower.

[0014] Optionally, the support assembly includes the measurement plate with a smooth surface and a preset number of bolts.

[0015] The measurement plate has a preset number of threaded holes; the threaded holes pass through the measurement plate; and the threaded holes are configured to install the bolts so that the measurement plate is installed inside the concrete tower through the bolts.

[0016] Optionally, the support assembly is two groups, and the strain measurement element is two.

[0017] The two groups of support assemblies are installed inside the concrete tower; the angle between the projection point of the installation point of the two groups of support assemblies on a target plane and the projection point of the center axis of the concrete tower on the target plane is 90 degrees; and the target plane is any plane perpendicular to the center axis of the concrete tower.

[0018] Optionally, the support assembly is four groups, and the strain measurement element is four.

[0019] The four groups of support assemblies are installed inside the concrete tower; the figure formed by connecting the projection points of the installation points of the four groups of support assemblies on a target plane is a square; and the target plane is any plane perpendicular to the center axis of the concrete tower.

[0020] Optionally, the linear load parameter includes a load proportionality coefficient and a load bias; the load proportionality coefficient and the load bias are calculated through the maximum measurement electric signal in the experimental measurement electric signal, the minimum measurement electric signal in the experimental measurement electric signal, and the concrete tower load under the self-weight of the machine head of the wind turbine generator.

[0021] The experimental measurement electric signal is obtained by outputting the strain measurement bridge when the head of the wind turbine generator is uniformly yawed for one circle under the wind condition.

[0022] Optionally, the measurement plate is installed horizontally or vertically to the axial direction of the concrete tower inside the concrete tower.

[0023] Optionally, the material of the support assembly is metal.

[0024] The embodiment of the application further provides a load monitoring method, which is applied to the wind turbine generator tower load monitoring system described above, and the wind turbine generator tower load monitoring system comprises a support assembly, a strain measurement element, a strain measurement bridge and a load output module; the support assembly is installed inside the concrete tower; the support assembly at least comprises a measurement plate with a smooth surface; the strain measurement element is installed on the measurement plate; the strain measurement element is used for measuring the strain of the concrete tower; the strain measurement element is included in the strain measurement bridge;

[0025] The method comprises the following steps:

[0026] Obtaining a measurement electric signal output by the strain measurement bridge according to the strain of the concrete tower measured by the strain measurement element;

[0027] Obtaining a linear load parameter; the concrete tower load and the measurement electric signal are in a linear relationship;

[0028] According to the measurement electric signal and the linear load parameter, the concrete tower load is calculated.

[0029] Optionally, the step of obtaining the linear load parameter comprises:

[0030] When the wind condition is met, the head of the wind turbine generator is uniformly yawed for one circle, and an experimental measurement electric signal output by the strain measurement element is obtained;

[0031] A load proportionality coefficient and a load bias are calculated through the maximum measurement electric signal in the experimental measurement electric signal, the minimum measurement electric signal in the experimental measurement electric signal and the concrete tower load under the self weight of the head of the wind turbine; the linear load parameter comprises the load proportionality coefficient and the load bias.

[0032] According to the above technical solution, the application has the following beneficial effects:

[0033] The embodiment of the present application provides a wind turbine tower load monitoring system and method, which is used for measuring a concrete tower load and comprises a support assembly, a strain measurement element, a strain measurement bridge and a load output module. The support assembly is installed on the inner side of the concrete tower, and the support assembly at least comprises a measurement plate with a smooth surface. The strain measurement element is installed on the measurement plate, and the strain measurement element is used for measuring the strain of the concrete tower. The strain measurement element is included in the strain measurement bridge, and the strain measurement bridge outputs a measurement electric signal according to the strain of the concrete tower measured by the strain measurement element. Wherein, the concrete tower load and the measurement electric signal are in a linear relationship. The load output module is used for acquiring the measurement electric signal, and calculating the concrete tower load according to the measurement electric signal and a linear load parameter. The strain measurement element provided by the embodiment of the present application is installed on the smooth measurement plate, so that the connection between the strain measurement element and the measurement plate is firm, the service time is long, the replacement frequency of the strain measurement element is reduced, and the long-term monitoring of the concrete tower load is suitable. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0035] Figure 1 A structural schematic diagram of a wind turbine tower load monitoring system provided by the embodiment of the present application is shown in the figure.

[0036] Figure 2a A top view and a side view of a support assembly provided by the embodiment of the present application are shown in the figure.

[0037] Figure 2b A three-dimensional space schematic diagram of a support assembly provided by the embodiment of the present application is shown in the figure.

[0038] Figure 3a An installation position schematic diagram of a measurement assembly provided by the embodiment of the present application is shown in the figure.

[0039] Figure 3b An installation position top view of a measurement assembly provided by the embodiment of the present application is shown in the figure.

[0040] Figure 4 A measurement electric signal curve diagram of a strain measurement full bridge provided by the embodiment of the present application is shown in the figure.

[0041] Figure 5 A flow chart of a load monitoring method provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0042] In order to make the above objectives, characteristics and advantages of the present application more apparent, further specific embodiments of the present application will be described in detail with reference to the accompanying drawings and specific embodiments.

[0043] In order to facilitate understanding and explanation of the technical solutions provided by the embodiments of the present application, the background art of the embodiments of the present application will be described first.

[0044] In recent years, the increasing demand for single machine capacity of wind turbine generators has led to the increasing of impeller diameter and tower height. The increase of tower height not only increases the cost of the tower, but also may cause a series of tower coupling vibration problems. Based on this, more and more towers are constructed not only with steel towers, but also with concrete towers, that is, the overall part of the tower is composed of steel towers and concrete towers. In order to improve the operation safety of the wind turbine generator, it is necessary to monitor the tower of the wind turbine generator for a long time to evaluate its technical characteristics.

[0045] The wind turbine generator needs to obtain type certification before bidding. After the same model tower is changed (especially after the tower natural frequency is changed), it is considered as a new model, and type certification must be made. One of the projects in type certification is type certification test. The mechanical load test in wind turbine generator type certification test is carried out in accordance with IEC61400-13-2017. The tower load must be included in the load measurement, that is, the tower bending moment, therefore, the measurement of the bending moment of the concrete tower is necessary.

[0046] Among them, the load measurement technology of the steel tower part included in the tower has been mature. However, compared with the traditional steel tower, the concrete tower is a new technology in wind power, which has no application history, and the load measurement technology of the concrete tower part needs to be improved.

[0047] At present, the load of the concrete tower can be inferred from the measured load of the steel tower. However, the inferred load of the concrete tower has the problem of inaccuracy. In order to solve this problem, the strain of the tower can be obtained by embedding the measuring rod device with strain gauges in the concrete tower, and then the load of the concrete tower can be directly obtained through the strain of the tower. This method solves the problem of inaccurate load acquisition of the concrete tower. However, the measuring rod device embedded in the concrete tower cannot be repaired once it is damaged and cannot be used for long-term monitoring. Moreover, the effect of the concrete tower on the strain gauge during embedding is complex, therefore, it is difficult to calibrate the signal of the strain gauge, and it is also difficult to obtain effective signals from the signal.

[0048] In addition, the strain gauge can be directly attached to the concrete tower to obtain the strain of the concrete tower through the strain gauge, and then the load of the concrete tower can be directly obtained through the strain of the concrete tower. When the strain gauge is damaged or fails, the strain gauge can be directly replaced. However, due to the particularity of concrete, there is no effective adhesive to ensure that the strain gauge is firmly attached to the concrete. The strain signal measured by the strain gauge directly attached to the concrete tower will continuously produce a creep characteristic, and a serious failure will occur within half a month or even a shorter time, so that the measurement result is unavailable, and the strain gauge needs to be replaced frequently.

[0049] Therefore, the embodiment of the present application provides a wind turbine tower load monitoring system and method for measuring the load of a concrete tower. The wind turbine tower load monitoring system comprises a support assembly, a strain measuring element, a strain measuring bridge circuit and a load output module. The support assembly is installed on the inner side of the concrete tower, and the support assembly at least comprises a measuring plate with a smooth surface. The strain measuring element is installed on the measuring plate, and the strain measuring element is used to measure the strain of the concrete tower. The strain measuring element is included in the strain measuring bridge circuit, and the strain measuring bridge circuit outputs a measurement electric signal according to the strain of the concrete tower measured by the strain measuring element. The load of the concrete tower and the measurement electric signal are in a linear relationship. The load output module is used to obtain the measurement electric signal, and calculate the load of the concrete tower according to the measurement electric signal and the linear load parameter. The strain measuring element provided by the embodiment of the present application is installed on the smooth measuring plate, so that the connection between the strain measuring element and the measuring plate is firm, the service time is long, the replacement frequency of the strain measuring element is reduced, and the long-term monitoring of the load of the concrete tower is suitable.

[0050] Referring to Figure 1 , Figure 1 FIG. 1 is a structural schematic diagram of a wind turbine tower load monitoring system provided by an embodiment of the present application. The wind turbine tower load monitoring system is used to measure the load of a concrete tower of a wind turbine. As shown in FIG. 1, the wind turbine tower load monitoring system comprises: Figure 1

[0051] a support assembly 1, a strain measuring element 2, a strain measuring bridge circuit 3 and a load output module 4.

[0052] The support assembly 1 is installed on the inner side of the concrete tower. The support assembly 1 at least comprises a measuring plate 5 with a smooth surface. Preferably, the measuring plate 5 is installed on the inner side of the concrete tower horizontally or vertically to the axial direction of the concrete tower.

[0053] ​The strain measurement element 2 is installed on the measurement plate 5. The number of the strain measurement element 2 is the same as that of the support assembly 1. The strain measurement element 2 measures the strain of the measurement plate 5, and the strain of the measurement plate 5 can directly reflect the strain of the concrete tower, so the strain measurement element 2 is used to measure the strain of the concrete tower. Since the measurement plate 5 has a smooth surface, instead of directly installing the strain measurement element 2 on the concrete tower, the strain measurement element 2 in the embodiment of the application is installed on the smooth surface of the measurement plate 5, and the strain measurement element 2 can be used for long-term measurement of the strain of the concrete tower and obtain the load of the concrete tower by means of the measurement plate 5. As an example, the strain measurement element 2 is a strain gauge. The strain gauge is pasted on the smooth surface of the measurement plate 5, so that the connection between the strain gauge and the measurement plate 5 is tight, and the strain gauge is not easy to fall off or fail.

[0054] Preferably, the material of the measurement plate 5 is a metal material, for example, an alloy steel material. Optionally, the strain measurement element 2 is installed on the smooth surface of the measurement plate 5 by means of pasting or welding.

[0055] The support assembly 1 is installed in different ways inside the concrete tower, and different installation ways make the structure of the support assembly 1 different, as follows:

[0056] As an example, the support assembly 1 includes the measurement plate 5 with a smooth surface, the first connecting component 6 and the second connecting component 7. As shown in Figure 2a and 2b , it is a top view and a side view of a support assembly provided by the embodiment of the application, Figure 2a Figure 2b it is a three-dimensional space schematic view of a support assembly provided by the embodiment of the application.

[0057] As shown in Figure 2a , 2b , one end of the first connecting component 6 is fixedly connected with one end of the measurement plate 5, and one end of the second connecting component 7 is fixedly connected with the other end of the measurement plate 5. In addition, the other end of the first connecting component 6 and the other end of the second connecting component 7 are both embedded inside the concrete tower.

[0058] Optionally, the material of the support assembly 1 is a metal material, for example, an alloy steel material. Optionally, when the material of each component of the support assembly 1 is a metal material, the first connecting component 6 and the second connecting component 7 are fixedly connected by means of welding, and stress concentration treatment is performed.

[0059] As another example, the support assembly 1 includes the measurement plate 5 with a smooth surface and a preset number of bolts. Correspondingly, the measurement plate 5 has a preset number of threaded holes, and the threaded holes penetrate the measurement plate 5. Each threaded hole is used to install a corresponding bolt to install the measurement plate 5 inside the concrete tower by means of the bolts. ​

[0060] It should be noted that the shapes of the measurement plate 5, the first connecting component 6 and the second connecting component 7 are not limited to the shapes in Figure 2a 、 2b , and can be determined according to actual requirements. In addition, the size of the support assembly 1 needs to be adjusted for different sizes of the concrete tower. Alternatively, the size of the support assembly 1 can be determined through simulation. Specifically, a modeling software is used to model the concrete tower and add models of the support assembly 1 and the strain measurement element 2. After modeling, the overall structure of the concrete tower is simulated by applying a bending moment. Since the strain force of the concrete tower can be transferred to the support assembly 1, if the strain size of the concrete tower measured by the strain measurement element 2 obtained through simulation is consistent with the strain size of the concrete tower, the strain force on the surface of the support assembly 1 can directly and truly reflect the strain force of the concrete tower. At this time, the size of the support assembly 1 is available. Essentially, the load on the surface of the support assembly 1 is calibrated, and the change in the load on the surface of the support assembly 1 is used to reflect the change in the load on the concrete tower.

[0061] Alternatively, a size scale can be made on each component of the support assembly 1 to facilitate obtaining the size of each component of the support assembly. Moreover, the materials selected for the strain measurement element 2 and the support assembly 1 require that the mechanical parameters of each material are known.

[0062] The wind turbine generator tower load monitoring system provided by the embodiment of the application further includes a strain measurement bridge circuit 3. The strain measurement element 2 is included in the strain measurement bridge circuit 3. The strain measurement bridge circuit 3 outputs a measurement electrical signal according to the strain of the concrete tower measured by the strain measurement element 2. The concrete tower load and the measurement electrical signal are in a linear relationship.

[0063] The strain measurement element 2 is included in the strain measurement bridge circuit 3. The strain of the concrete tower measured by the strain measurement element 2 is converted into a measurement electrical signal by the strain measurement bridge circuit 3. Through experiments, it is found that the concrete tower load and the measurement electrical signal are in a linear relationship. Therefore, after obtaining the measurement electrical signal, the concrete tower load can be directly obtained according to the linear relationship between the concrete tower load and the measurement electrical signal.

[0064] As an example, the measurement electrical signal is an output voltage of the strain measurement bridge circuit 3. As another example, the measurement electrical signal is a ratio of an output voltage to an input voltage of the strain measurement bridge circuit 3.

[0065] It should be noted that the strain measurement bridge circuit 3 can be designed as a single-bridge circuit, a half-bridge circuit and a full-bridge circuit. Specifically as follows:

[0066] As an alternative, the strain measurement bridge circuit 3 is designed as a single bridge circuit. The support assembly 1 is one set, and the strain measurement element 2 is one. The support assembly 1 is installed inside the concrete tower. The specific installation position of the support assembly 1 is not limited.

[0067] As another alternative, the strain measurement bridge circuit 3 is designed as a half bridge circuit. The support assembly 1 is two sets, and the strain measurement element 2 is two. In this case, the two sets of support assemblies 1 are installed inside the concrete tower, and the installation points of the two sets of support assemblies 1 form an angle of 90 degrees with the projection points of the target plane and the projection points of the central axis of the concrete tower in the target plane, wherein the target plane is any plane perpendicular to the central axis of the concrete tower.

[0068] One support assembly 1 and the corresponding strain measurement element 2 are regarded as one measurement assembly. That is, the projection of the concrete tower on the target plane is a circle, and the two sets of measurement assemblies are evenly distributed in two directions inside the concrete tower. The two directions are marked as 0 degrees and 90 degrees on the circle. In addition, preferably, in order to facilitate the strain measurement bridge circuit 3 to obtain the measurement electrical signal, when there are multiple measurement assemblies, the multiple measurement assemblies are on the same horizontal line.

[0069] In order to improve the sensitivity of the strain measurement element 2, reduce the heating of the strain measurement element 2 itself, and offset the influence of temperature changes on the measurement electrical signal, the strain measurement bridge circuit 3 can be preferably designed as a full bridge circuit. Referring to Figure 3a 、 3b , Figure 3a For Figure 3a For the installation position of the measurement assembly provided in the embodiment of the application, Figure 3b is a top view of the installation position of the measurement assembly provided in the embodiment of the application.

[0070] As Figure 3a 、 3b shown, the support assembly 1 is four sets, and the strain measurement element 2 is four. As an example, Figure 3a 、 3b The support assembly 1 in Figure 3a 、 3b is not limited to the structure in Figure 3a 、 3bAs shown, the projection of the concrete tower on the target plane is a circle, or the top view of the concrete tower is a circle, and the four groups of measurement components are evenly distributed in the inside of the concrete tower in four directions. The four directions are marked as 0 degrees, 90 degrees, 180 degrees, and 270 degrees on the circle. The measurement component in the 0-degree direction and the measurement component in the 180-degree direction form one group in the strain measurement full bridge, and the measurement component in the 90-degree direction and the measurement component in the 270-degree direction form one group in the strain measurement full bridge, together forming a strain measurement full bridge.

[0071] Preferably, in order to facilitate the strain measurement bridge 3 to obtain the measurement electrical signal, when there are multiple measurement components, the multiple measurement components are on the same horizontal line.

[0072] The load output module 4 in the wind turbine tower load monitoring system is used to obtain the measurement electrical signal output by the strain measurement bridge 3, and calculate the concrete tower load according to the measurement electrical signal and the linear load parameter.

[0073] The linear load parameter includes a load proportionality coefficient and a load bias. It should be noted that the linear load parameter needs to be obtained first, and then based on the linear load parameter, the concrete tower load can be calculated after obtaining the measurement electrical signal.

[0074] As an example, the linear load parameter is obtained by calibration. In the last stage of the calibration process, the linear load parameter can be calculated by experimentally measuring the maximum measurement electrical signal in the measurement electrical signal, the minimum measurement electrical signal in the measurement electrical signal, and the concrete tower load under the self-weight of the nacelle of the wind turbine. The experimental measurement electrical signal is obtained by outputting the strain measurement bridge 3 when the wind turbine meets the wind conditions and makes the nacelle yaw at a uniform speed for one revolution.

[0075] In order to facilitate understanding, the principle of calibration is as follows:

[0076] A known bending moment is applied to the concrete tower, and then the relationship between the measurement electrical signal and the actual bending moment (i.e. load) of the concrete tower is obtained according to the known bending moment applied and the measurement electrical signal of the strain measurement bridge 3:

[0077] M = K * S + of

[0078] Where M is the actual bending moment of the concrete tower, K is the load proportionality coefficient, S is the measurement electrical signal output by the strain measurement bridge 3, and of is the load bias. It can be seen that M and S are in a linear relationship.

[0079] In specific implementation, the actual calibration process is as follows:

[0080] When the wind speed is below 5m / s or there is no wind, the thrust of the wind on the wind turbine rotor is approximately zero, and the bending moment on the concrete tower is caused by the weight of the nacelle, which is known as M0. In this case, the nacelle is made to yaw at a constant speed for one revolution. As an example, the nacelle is made to yaw clockwise at a constant speed for one revolution, as shown in FIG. 2. Figure 3b The output electrical signal of the strain measurement bridge 3 is shown in FIG. 3. Figure 4 Figure 4 The measurement electrical signal curve of the strain measurement full bridge provided by the embodiment of the present application is shown in FIG. 4. During the yawing of the nacelle for one revolution, when the nacelle turns to the position where the strain measurement element 2 is installed, the measurement electrical signal output by the strain measurement bridge 3 is the maximum, and the bending moment is the maximum. As shown in FIG. 4, Figure 4 the maximum measurement electrical signal is the measurement electrical signal corresponding to point A, which is denoted as S A , and the known bending moment is M0, which is the maximum bending moment. The minimum measurement electrical signal is the measurement electrical signal corresponding to point C, which is denoted as S C , and the known bending moment is -M0, which is the minimum bending moment. The positive and negative signs only represent pressure or tension, for example, the positive sign represents pressure, and the negative sign represents tension. Figure 4 The vertical coordinate (measurement electrical signal) in FIG. 4 is specifically a voltage ratio signal, i.e., the voltage ratio of the output voltage and the input voltage of the strain measurement bridge 3. The horizontal coordinate is time.

[0081] The calculation formula of the load proportionality coefficient K and the load offset of is as follows:

[0082] M0 = K * S A + of

[0083] -M0 = K * S C + of

[0084] Based on the formula, the load proportionality coefficient K and the load offset of can be obtained according to the measurement electrical signals S A , S C output by the strain measurement circuit 3 and the bending moment M0 caused by the weight of the nacelle.

[0085] Thus, the calibration process of the measurement electrical signal and the concrete tower load is completed. When the measurement electrical signal is known, the actual bending moment of the concrete tower can be directly output by using the obtained load proportionality coefficient K and the load offset of.

[0086] It should be noted that the calibration method of the measurement electrical signal and the concrete tower load is not limited to the above calibration method, and the above calibration process is only used as an example to describe the calibration process of the measurement electrical signal and the concrete tower load.

[0087] ​If the measured value changes obviously during the monitoring of the concrete tower load, it is necessary to check whether the strain measurement element 2 is damaged, and when the strain measurement element 2 is damaged or fails, the strain measurement element 2 can be reinstalled and calibrated according to the wind turbine tower load monitoring system and method provided in the embodiment of the application. As long as the parameters of the strain measurement element 2 are consistent, the load proportional coefficient K and the load bias of obtained by each calibration will be small, and once the load proportional coefficient K and the load bias of obtained by calibration are large, the concrete structure needs to be checked or inspected.

[0088] For long-term monitoring, the bending moment load values of the wind turbine unit under the same operating condition should be consistent within the uncertainty. The tower health can be monitored by the change of the bending moment load value. In addition, the tower health can also be monitored by measuring the frequency domain characteristics of the electrical signal. Specifically, the tower health is monitored by analyzing the frequency components of the measured electrical signal. Once the frequency components of the measured electrical signal change under the same operating condition, the concrete structure needs to be checked or inspected.

[0089] The wind turbine tower load monitoring system provided in the embodiment of the application directly measures the load of the concrete tower through the support assembly, the strain measurement element, the strain measurement bridge and the load output module, improves the accuracy of the obtained concrete tower load, and can be used for type certification test of the wind turbine unit. Moreover, when the components in the wind turbine tower load monitoring system fail, the wind turbine tower load monitoring system provided in the embodiment of the application can be easily repaired, and can be used for long-term monitoring of the concrete tower load.

[0090] Referring to Figure 5 , Figure 5 A flowchart of a load monitoring method provided in the embodiment of the application is provided, and the method is applied to the wind turbine tower load monitoring system in the above embodiment. The wind turbine tower load monitoring system comprises a support assembly, a strain measurement element, a strain measurement bridge and a load output module. The support assembly is installed on the inside of the concrete tower. The support assembly at least comprises a measurement plate with a smooth surface. The strain measurement element is installed on the measurement plate. The strain measurement element is used to measure the strain of the concrete tower. The strain measurement element is included in the strain measurement bridge.

[0091] As Figure 5 shown, the method comprises S501-S503:

[0092] S501: Obtain the measurement electrical signal output by the strain measurement bridge according to the strain of the concrete tower measured by the strain measurement element.

[0093] S502: Obtain the linear load parameter; the concrete tower load and the measurement electrical signal are in a linear relationship.

[0094] S503: calculating the concrete tower load according to the measured electrical signal and the linear load parameter.

[0095] In practice, the linear load parameter includes:

[0096] When the wind condition is met, the head of the wind turbine generator set is uniformly yawed for one circle, and the experimental measured electrical signal output by the strain measurement element is obtained;

[0097] The load proportionality coefficient and the load bias are calculated through the maximum measured electrical signal in the experimental measured electrical signal, the minimum measured electrical signal in the experimental measured electrical signal, and the concrete tower load under the self weight of the fan head; the linear load parameter includes the load proportionality coefficient and the load bias.

[0098] It should be noted that the load monitoring method provided by the embodiments of the present application is applied to the wind turbine generator set tower load monitoring system of the foregoing embodiments, and the related functions and principles of the wind turbine generator set tower load monitoring system can be referred to the foregoing embodiments, which will not be described here.

[0099] The embodiments of the present application provide a load monitoring method, which is applied to a wind turbine generator set tower load monitoring system and used for measuring a concrete tower load. The method includes: obtaining a measured electrical signal output by a strain measurement bridge according to a strain measured by a strain measurement element of the concrete tower; obtaining a linear load parameter, wherein the concrete tower load and the measured electrical signal are in a linear relationship; and calculating the concrete tower load according to the measured electrical signal and the linear load parameter. The strain measurement element in the method is installed on a smooth measurement plate, so that the connection between the strain measurement element and the measurement plate is firm, the service time is long, and the replacement frequency of the strain measurement element is reduced, which is suitable for long-term monitoring of the concrete tower load.

[0100] It should be noted that the embodiments in the present specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts of each embodiment can be referred to each other. For the method disclosed in the embodiments, since it corresponds to the system disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the system part.

[0101] It is also to be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component" can include a combination of two or more components, and the term "an element" can include comparable reference to a plurality of elements.

[0102] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Numerous modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wind turbine tower load monitoring system, characterized in that, Used for measuring loads on concrete towers, including: support components, strain measurement elements, strain measurement bridge circuit, and load output module; The support assembly is installed inside the concrete tower; the support assembly includes at least a measuring plate with a smooth surface; The strain measuring element is mounted on the measuring plate; the strain measuring element is used to measure the strain of the concrete tower. The strain measurement bridge circuit includes a strain measurement element; the strain measurement bridge circuit outputs a measurement electrical signal based on the strain of the concrete tower measured by the strain measurement element. The load output module is used to acquire the measured electrical signal and calculate the load on the concrete tower based on the measured electrical signal and the linear load parameters. The linear load parameters include a load proportionality coefficient and a load offset. The load proportionality coefficient and the load offset are calculated by the maximum measured electrical signal, the minimum measured electrical signal, and the load on the concrete tower under the self-weight of the wind turbine generator head. The experimental measured electrical signal is obtained by outputting the strain measurement bridge circuit when the wind turbine generator head is yawed at a constant speed for one revolution to meet the wind conditions. The concrete tower load and the measured electrical signal are linearly related. The concrete tower load is equal to the sum of the product of the measured electrical signal and the load proportionality coefficient, and the load offset.

2. The system according to claim 1, characterized in that, The support assembly includes the measuring plate with a smooth surface, a first connecting component, and a second connecting component; One end of the first connecting component is fixedly connected to one end of the measuring plate, and one end of the second connecting component is fixedly connected to the other end of the measuring plate; the other ends of the first connecting component and the other ends of the second connecting component are both embedded inside the concrete tower.

3. The system according to claim 1, characterized in that, The support assembly includes the measuring plate with a smooth surface and a predetermined number of bolts; The measuring plate has a preset number of threaded holes; the threaded holes penetrate the measuring plate; the threaded holes are used to install the bolts so that the measuring plate is installed on the inside of the concrete tower through the bolts.

4. The system according to any one of claims 1-3, characterized in that, The support components consist of two sets, and the strain measurement elements consist of two components; The two sets of support components are installed on the inner side of the concrete tower; the angle formed by the projection of the installation points of the two sets of support components onto the target plane and the projection of the central axis of the concrete tower onto the target plane includes 90 degrees; the target plane is any plane perpendicular to the central axis of the concrete tower.

5. The system according to any one of claims 1-3, characterized in that, The support components consist of four sets, and the strain measurement elements consist of four. The four sets of support components are installed on the inner side of the concrete tower; the figure formed by connecting the projection points of the four sets of support components on the target plane is a square; the target plane is any plane perpendicular to the central axis of the concrete tower.

6. The system according to claim 1, characterized in that, The measuring plate is installed horizontally or perpendicularly to the axial direction of the concrete tower on the inner side of the concrete tower.

7. The system according to claim 1, characterized in that, The support component is made of metal.

8. A load monitoring method, characterized in that, The wind turbine tower load monitoring system according to any one of claims 1-7 includes: a support assembly, a strain measuring element, a strain measuring bridge, and a load output module; the support assembly is installed inside the concrete tower; the support assembly includes at least a measuring plate with a smooth surface; the strain measuring element is installed on the measuring plate; the strain measuring element is used to measure the strain of the concrete tower; and the strain measuring bridge includes the strain measuring element. The method includes: The strain measurement bridge circuit outputs a measurement electrical signal based on the strain of the concrete tower measured by the strain measurement element; Obtain linear load parameters; The load on the concrete tower is calculated based on the measured electrical signal and the linear load parameters; The linear load parameters include a load proportionality coefficient and a load offset. The load proportionality coefficient and the load offset are calculated by the maximum measured electrical signal, the minimum measured electrical signal, and the load on the concrete tower under the self-weight of the wind turbine generator head. The experimental measured electrical signal is obtained by outputting the strain measurement bridge circuit when the wind turbine generator head is yawed at a constant speed for one revolution to meet the wind conditions. The concrete tower load and the measured electrical signal are linearly related. The concrete tower load is equal to the sum of the product of the measured electrical signal and the load proportionality coefficient, and the load offset.

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