Omni-directional coupling distributed super-high hybrid tower wind turbine cluster monitoring method and device

Abstract

The application discloses a comprehensive coupling distributed super-high hybrid tower wind turbine cluster monitoring method and device, and belongs to the technical field of wind power structure health monitoring. The application first creates a "1+N" distributed targeted monitoring model: first, based on wind field wake simulation and turbulence intensity analysis, the most seriously disturbed single unit is dynamically positioned as the core host site (1) for comprehensive monitoring; second, the remaining distributed units (N) are directionally and simply monitored in relation to four key modules of wind wheel blades, prestressed steel strands, tower body vibration and concrete cracking. The application synchronously captures the coupling failure mechanism of structural dynamic response and static deformation through a heterogeneous sensor group, solves the problems of fragmentation and lack of risk targeting of existing monitoring schemes, and at the same time, the architecture realizes the combination of deep perception of the host site and modular monitoring of the subunit, significantly reduces the hardware cost compared with the full coverage scheme, and provides a full life cycle monitoring paradigm for the hybrid tower wind farm cluster.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mixed tower wind turbine cluster health monitoring, and relates to a comprehensive coupling distributed super-high mixed tower wind turbine cluster monitoring method and device. BACKGROUND

[0002] With the development of large-scale wind turbines and clusterization of wind farms, super-high mixed tower wind turbines (concrete-steel hybrid tower) have become the mainstream choice in low wind speed areas due to their economy and high adaptability. However, the mixed tower structure has the characteristics of creep of concrete, stress sensitivity of prestressed steel strand and large deformation of long and flexible blades, which is prone to cause blade overload, tower dynamic instability, anchor cable prestress loss, concrete cracking and foundation settlement and other chain structure risks in complex wind field environment (such as wake interference, terrain turbulence). The existing wind farm cluster monitoring scheme has significant limitations:

[0003] Fragmented monitoring: the mainstream commercial system focuses on a single parameter (such as vibration or inclination), and lacks coupling correlation monitoring design for multiple modules such as blade load, anchor cable tension and concrete stress;

[0004] Economic imbalance: in order to achieve full coverage, high-density sensors are deployed on all units, resulting in a sharp increase in monitoring costs, which violates the principle of intensive management of wind farms;

[0005] Risk targeting loss: without combining the spatial and temporal distribution characteristics of wind resources to identify high-risk units in the cluster, the monitoring resource allocation is disconnected from the actual risk. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a comprehensive coupling distributed super-high hybrid tower wind turbine cluster monitoring method and device to solve the above-mentioned problems of the prior art. The present application designs a comprehensive structural health and safety monitoring scheme. The "1+N" "comprehensive coupling distributed" monitoring idea is adopted. First, the wind speed profile and turbulence intensity profile of each wind turbine are calculated through the wind resource calculation, and the wind turbine most affected by the wake and topography is determined as the "1+N" 1 master site comprehensive monitoring hybrid tower unit. For the master site comprehensive monitoring hybrid tower unit, a high-precision hybrid tower wind turbine model and mechanical property analysis are established, and GNSS, dynamic and static strain gauges, anchor gauges, accelerometers, inclinometers, joint meters and static leveling instruments are arranged at the corresponding structural dangerous points for monitoring design, which comprehensively ensures the safe operation of the hybrid tower wind turbine. Secondly, the N of "1+N" corresponds to four key structural modules of the hybrid tower wind turbine: wind turbine blades, prestressed steel strands, hybrid tower vibration and hybrid tower cracking, which correspond to blade load, prestressed anchor tension, hybrid tower cylinder dynamic parameters (displacement, inclination, vibration) and hybrid tower cylinder concrete cracking (local stress, foundation settlement). The comprehensive coupling distributed super-high hybrid tower wind turbine cluster monitoring design formed thereby realizes efficient and comprehensive monitoring scheme design and implementation of multiple angles, multiple structural modules and multiple monitoring parameters of the hybrid tower wind turbine cluster, considers the health operation of all key structures of the hybrid tower wind turbine, and considers the economic monitoring management of the wind turbine cluster. This method is suitable for ensuring the health service of the hybrid tower wind turbine cluster throughout its life.

[0007] To achieve the above technical purposes, the technical scheme adopted by the present application is:

[0008] The comprehensive coupling distributed super-high hybrid tower wind turbine cluster monitoring method and device comprises the following steps:

[0009] Step 1: Based on the wind field inflow wind resource information and wind turbine parameters, the wind speed profile and turbulence intensity profile of each hybrid tower wind turbine in the field are calculated through the wind resource distribution model, and the single unit most affected by the wake and topography is identified as the core master site;

[0010] Step 2: On the core master site, corresponding sensor groups are deployed for monitoring all structural modules,

[0011] Step 3: On the remaining distributed units other than the core master site, one or more of all structural modules are selected, and corresponding sensor groups are deployed for monitoring;

[0012] Step 4: The monitoring data of the core master site and the distributed units are fused to realize multi-parameter, multi-module coupling health state evaluation and early warning of the hybrid tower wind turbine cluster.

[0013] To optimize the above technical solutions, the specific measures taken also include:

[0014] In step 1, the wind field inflow wind resource information includes: the inflow wind speed U of the wind turbine hub height position hub And the turbulence intensity I hub , the ground roughness z0 and the exponential wind profile parameter α; the wind turbine parameters include the longitude and latitude coordinates or relative positions (x wake , y wake , z wake ) of each unit, the wind wheel diameter D, the wind turbine hub height z hub And the wind turbine thrust coefficient C t And the wind turbine power coefficient C p .

[0015] In step 1, the wind speed profile and turbulence intensity profile of each hybrid tower wind turbine in the field are calculated by the wind resource distribution model, and the specific method for identifying the single unit most affected by the wake and topography as the core main unit is:

[0016] Step 11, construct the wind shear curve:

[0017] According to the basic law of turbulent motion in the boundary layer, the logarithmic law or exponential law is used to calculate the inflow wind speed profile u0(z) and turbulence intensity profile I0(z) considering the wind shear effect:

[0018]

[0019] Or

[0020]

[0021] In the formula: z is the vertical height; z0 is the ground roughness height; z ref is the reference height, when the logarithmic law wind profile is applied to the field of wind power, the reference height z ref Take the wind turbine hub height z hub , at this time the corresponding reference wind speed u(z ref ) = U hub , the corresponding reference turbulence intensity I(z ref ) = I hub ;

[0022] Step 12, calculate the wake radius of the wind turbine downstream x flow direction position :

[0023]

[0024] In the formula, is the wind wheel radius, x is the flow direction distance between any position downstream of the wind turbine and the position of the wind wheel,

[0025] Step 13, Calculate the turbulence intensity distribution of the computer group wake region:

[0026] Step 131, Calculate the maximum additional turbulence intensity I add, max (x) of the x position of the wake region

[0027] Step 132, Calculate the additional turbulence intensity I add (x, y, z) at the wake (x, y, z)

[0028] where, is the distance between any position (x, y, z) and the center point (x, , ) of its x-section, y and z are the coordinates in the crosswind and vertical directions, respectively,

[0029] Step 133, Calculate the suppression turbulence intensity of the wind turbine wake :

[0030]

[0031] Step 134, Calculate the streamwise turbulence intensity :

[0032]

[0033] Step 135, Calculate the wind speed profile of each group and the inflow and wake characteristics:

[0034] (1) After determining the wind turbine wake region by the wake radius r x and the radial radius r with the wind wheel center line as the center, calculate the average wake velocity u * (x, z) of the wake region at the vertical direction height z position at the downstream x distance of the wind turbine, which is used as the initial predicted velocity, and its expression is:

[0035]

[0036] where: s is the dimensionless downstream position of the wind turbine wake region, k x,z is the modified wake expansion coefficient representing the influence of environmental turbulence intensity and additional turbulence intensity at the downstream x distance and height z position of the wind turbine, which is calculated by the following formula:

[0037]

[0038] where: I wake,x,zThe effective turbulence intensity at the downstream x distance and height z position of the wind turbine is calculated by the following formula:

[0039]

[0040] In the formula, I add,x The additional turbulence intensity at the x position of the wake area is expressed as:

[0041]

[0042] (2) Calculate the wake area velocity u(x, y, z) of each unit in the field area, and define the wind speed distribution function f x,r The cosine type discrete distribution of the downstream x position wake velocity is:

[0043]

[0044] Further combined with the inflow wind speed profile u0(z), the average wake velocity u * (x, z) and the wind speed distribution function f x,r The wind turbine wake area velocity u(x, y, z) is obtained:

[0045]

[0046] (3) Considering the influence of multiple wind turbines in the field area, on the basis of the single wake area velocity u(x, y, z) of each unit calculated in step (2), the velocity distribution in the field area is obtained, and the square root sum model is used to calculate the superposition wake effect of each unit:

[0047]

[0048] In the formula, u is the wind speed at any position in the field area, u0 is the inflow wind speed at the corresponding height, u i is the wake velocity of each single unit at the corresponding position, and n represents the number of wind turbines in the field area;

[0049] Step 134, through the calculation method of steps 131-133, the wind speed profile and turbulence intensity profile of each hybrid tower wind turbine are calculated, the influence of the wake of each hybrid tower wind turbine is identified, and the single unit most affected by the wake and topography is selected as the core main unit based on the topography of each hybrid tower wind turbine.

[0050] In step 2, the structural module of the hybrid tower wind turbine includes wind turbine blades, prestressed steel strands, hybrid tower drum vibration, hybrid tower drum concrete cracking and foundation settlement structural modules, wherein the wind turbine blade module corresponds to a dynamic surface strain gauge, the prestressed steel strand module corresponds to an anchor cable gauge, the hybrid tower drum vibration module corresponds to an accelerometer, GNSS and an inclinometer, and the hybrid tower drum concrete cracking and foundation settlement structural module corresponds to a joint meter and a static level gauge.

[0051] For the wind turbine blade module: a plurality of dynamic surface strain gauges are arranged at the root section of each wind turbine blade;

[0052] For the prestressed steel strand module: at least four orthogonally arranged steel strands are selected to install anchor cable gauges according to the cable force deviation of all prestressed steel strands;

[0053] For the hybrid tower drum vibration module: bidirectional accelerometers are deployed at the steel-concrete transition zone and one or more key sections along the tower height, and inclinometers are installed at the tower top platform and / or the steel-concrete transition zone;

[0054] For the hybrid tower drum concrete cracking and foundation settlement structural module: joint meters are deployed at the steel-concrete transition zone and the vertical joints of the concrete section, and static level gauges are deployed on the foundation platform.

[0055] In step 4, the monitoring data of the fusion core host and the distributed unit are fused to realize the specific method of multi-parameter and multi-module coupling health state evaluation and early warning of the hybrid tower wind turbine cluster:

[0056] Step 41: finite element analysis modeling of the hybrid tower wind turbine:

[0057] The tail vortex of the wind turbine is simplified as a closed vortex ring, the tower drum is simplified as a cylinder, the foundation is simplified as a round pier, and the nacelle is simplified as a mass block. A multi-steel structure dynamic vibration analysis model of the wind turbine blade-tower drum-foundation is established by using a coupled multi-body dynamics method. Based on the extended Hellinger-Reissner variational principle, the motion equation of the whole machine dynamic model is derived. The rigid connection or spring damping system is used between the blade-nacelle, nacelle-tower drum, tower drum connecting section and tower drum and foundation, respectively, to establish a wind turbine multi-body dynamics model considering geometric nonlinearity. The specific implementation is as follows:

[0058] (1) The mixed tower is the core of modeling. First, the cross-sectional shape of the mixed tower section is drawn in the drawing software, including the inner and outer diameters and the split lines of the ring pieces. Then, the cross section is rotated 360° around the center axis to generate the solid model of the ring pieces. For the split ring section, multiple independent entities need to be generated according to the split lines. The steel tower section, anchor, steel flange and steel gasket need to be modeled separately and ensure that the connection surface matches the mixed tower section. In the selection of unit type, the concrete tower section, steel tower section, foundation, steel flange and steel gasket adopt three-dimensional eight-node hexahedral linear reduced integration unit, and ordinary steel bars and prestressed steel strands adopt two-node linear beam unit. In the simulation process, all components are divided into structural grids. The mixed tower section adopts C65 concrete and uses the concrete damage plasticity in the Abaqus analysis software. The prestress of the mixed tower is applied by the cooling method, that is, the corresponding components are cooled first to make the components shrink, and then the components are fixed to make the concrete tower obtain prestress.

[0059] (2) According to the geometric shape, material and structural layer information of the reference wind turbine blade design, a shell element structure wind turbine blade finite element model is established,

[0060] (3) The blade is connected to form a complete wind wheel through the rigid hub based on the elevation angle and the taper angle, and then the wind wheel is assembled with the tower through the rigid chassis. The hub weight and the weight of the nacelle are placed at the respective center of gravity positions in the form of point mass. The shell element-solid element coupling wind turbine generator finite element is used to assemble the finite element model.

[0061] Step 42: Analysis of the mechanical properties of the super-high mixed tower wind turbine generator:

[0062] For the foundation, mixed tower structure and tower prestressed steel strand parts of the mixed tower wind turbine generator, harmonic response analysis and transient response analysis are performed to obtain the static and dynamic characteristics of the mixed tower under wind load and the displacement response caused by the rotation of the wind wheel. The dynamic response of each main part of the mixed tower under different frequencies is obtained, as well as the structural deformation and stress corresponding to the peak frequency. Considering the influence of variable pitch angle under different wind speeds, the displacement, velocity and acceleration of each main part of the mixed tower at each time are calculated. The stress of the dangerous points of the tower bottom, tower joint and tower connection section is obtained, as well as the relationship between the displacement and related parameters of the tower top and steel-mixed connection. Then, the health status evaluation of each mixed tower wind turbine generator is realized. According to the health status evaluation result, the state of the mixed tower wind turbine generator is warned.

[0063] The omnibearing coupling distributed super-high hybrid tower wind turbine cluster monitoring system is used for realizing the omnibearing coupling distributed super-high hybrid tower wind turbine cluster monitoring method, and comprises a wind resource analysis module, a sensor network, a data acquisition and transmission module and a data fusion and health evaluation module.

[0064] The wind resource analysis module is used for executing the wind resource analysis and core host site identification step.

[0065] The sensor network comprises omnibearing sensor groups arranged at the core host sites and targeted sensor groups arranged at the distributed units.

[0066] The data acquisition and transmission module is used for acquiring and transmitting the data of the sensor network.

[0067] The data fusion and health evaluation module is used for executing the data fusion and health evaluation step.

[0068] A computer readable storage medium, which stores a computer program, when the program is executed by a processor, realizes the method.

[0069] Compared with the prior art, the beneficial effects of the present application are as follows:

[0070] (1) The present application creates a "1+N" distributed targeted monitoring model: based on wind field wake simulation and turbulence intensity analysis, the most seriously disturbed core host site (1) is dynamically positioned, realizing the risk focusing of "point to area"; at the same time, the hybrid tower is decomposed into four core modules (N) of blades, anchor cables, tower vibration and concrete cracking, and the coupling failure mechanism (such as the transmission chain of blade aerodynamic load→tower vibration→concrete crack propagation) of structure dynamic response and static deformation is synchronously captured through a heterogeneous sensor group of GNSS, strain gauge, anchor cable meter and static level gauge;

[0071] (2) Economic optimization: the combination of full-parameter monitoring of the host site and modular monitoring of the subunit reduces the hardware cost by more than 60% compared with the full coverage scheme, and realizes the "precise monitoring-global evaluation" closed loop through the extrapolation of high-risk unit data to the cluster state.

[0072] (3) The present application integrates wind resource driving, structure coupling and life cycle management into a unified framework, and provides a paradigm-level solution for the hybrid tower wind farm cluster, which has safety robustness and operation economy. BRIEF DESCRIPTION OF DRAWINGS

[0073] Figure 1 It is a structural schematic view of the super-high hybrid tower wind turbine.

[0074] Figure 2Layout of 7 hybrid tower wind turbines in a wind farm

[0075] Figure 3 Flow chart for wind resource calculation

[0076] Figure 4 Diagram of wind resource distribution at the location of #1 unit

[0077] Figure 5 Diagram of wind resource distribution at the location of #2 unit

[0078] Figure 6 Diagram of wind resource distribution at the location of #3 unit

[0079] Figure 7 Diagram of wind resource distribution at the location of #4 unit

[0080] Figure 8 Diagram of wind resource distribution at the location of #5 unit

[0081] Figure 9 Diagram of wind resource distribution at the location of #6 unit

[0082] Figure 10 Diagram of wind resource distribution at the location of #7 unit

[0083] Figure 11 Diagram of finite element analysis model of hybrid tower wind turbine

[0084] Figure 12 Diagram of stress distribution of tower

[0085] Figure 13 Diagram of displacement, velocity and acceleration at the top of tower

[0086] Figure 14 Diagram of horizontal strain distribution at the transition between hybrid tower, concrete section and steel-concrete

[0087] Figure 15 Diagram of prestress distribution of prestressed tendon of hybrid tower

[0088] Figure 16 Diagram of 1+N comprehensive coupling distributed monitoring design of 5 hybrid tower wind turbine clusters

[0089] Figure 17 Diagram of monitoring scheme design for comprehensive monitoring of #4 unit

[0090] Figure 18 Diagram of monitoring scheme design for #7 unit wind wheel blade

[0091] Figure 19 Diagram of monitoring scheme design for #3 unit prestressed steel strand

[0092] Figure 20 The scheme design drawing for monitoring the vibration of the tower drum of the No. 5 unit mixed tower;

[0093] Figure 21 The scheme design drawing for monitoring the concrete cracking of the tower drum of the No. 1 unit mixed tower. DETAILED DESCRIPTION

[0094] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is described and explained below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. Based on the examples provided in the present application, all other examples obtained by those of ordinary skill in the art without making creative efforts fall within the scope of the present application.

[0095] Obviously, the drawings in the following description are only some examples or embodiments of the present application, and for those of ordinary skill in the art, the present application can also be applied to other similar scenarios without making creative efforts based on these drawings. In addition, it can also be understood that although the efforts made in this development process can be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present application, some design, manufacturing or production changes based on the technical content disclosed in the present application are only routine technical means and should not be understood as insufficient disclosure of the present application.

[0096] The present application proposes a kind of based on all-around coupling distributed super high mixed tower wind turbine cluster monitoring design, it is intended to face super high mixed tower wind turbine cluster and provide a kind of multi-parameter, multi-angle, high economy and high security monitoring thought, for the health service of super high mixed tower wind turbine provides efficient application scheme.

[0097] REFERENCE Figure 1 The center distance of the tower drum of super high mixed tower wind turbine from the ground is more than 160m, and the transition zone of the steel tower section and the concrete section of the mixed tower wind turbine is about 3 / 4 of the tower height from the ground. The steel-concrete transition to the ground is the concrete section tower structure, and the steel-concrete transition to the top of the tower is the steel tower structure.

[0098] REFERENCE Figure 2 In a mixed tower wind turbine wind farm in a certain area in China, there are 7 units, and the 7 wind turbines are marked as 1#, 2#, 3#, 4#, 5#, 6# and 7#, which are distributed in a strip shape, wherein #4 is located at the geometric center of the cluster and is adjacent to the wind field anemometer tower; #3 and #5 are adjacent to the central area, #1 and #2 are adjacent to the main road of the wind field, and #6 and #7 are close to farmland.

[0099] According to the wind resource information of the wind farm, the wake effect of the wind turbine can cause the downstream wind speed to decrease, the turbulence intensity to increase, and the wind shear to intensify. The decrease in wind speed reduces the output power of the downstream turbine, and strong turbulence and additional wind shear also affect the fatigue load, structural performance, and service life of the downstream turbine. For a wind farm with limited scale, the wind turbines within the wind farm inevitably operate in the wake of surrounding turbines, and the wake effect becomes an important factor to be considered when arranging and optimizing the wind turbines of the wind farm.

[0100] Referring to Figure 3 , based on the measured data of the wind farm (hub height wind speed, turbulence intensity, and surface roughness) and the parameters of the wind turbine (wind wheel diameter, thrust coefficient), an inflow wind shear curve and turbulence intensity distribution model is constructed. Through the position information of the wake wind turbine and the initial wake expansion coefficient, an iterative calculation process is started: the wake expansion diameter is dynamically corrected according to the axial flow factor-thrust coefficient coupling equation, and the wake speed distribution function is used to layer by layer superimpose the influence of the upstream turbine wake, and finally the corrected wake field distribution of each site of the seven hybrid tower wind turbines in the wind farm is calculated. The specific implementation steps are as follows:

[0101] Step 1: Obtain the wind resource parameters of the inflow of the wind farm and the information of each turbine in the field

[0102] (1) The wind resource information of the inflow of the wind farm mainly includes: the inflow wind speed U hub and the turbulence intensity I hub of the hub height position of the wind turbine, and the vertical distribution of the inflow turbulence wind flow direction velocity (obtained by a multi-point wind measurement device, or the surface roughness z0 required for the logarithmic wind profile or the parameter a of the exponential wind profile).

[0103] (2) The information of each turbine in the field includes: the position information of each turbine (the longitude and latitude coordinates of each turbine or the relative position (x wake , y wake , z wake )) and the corresponding turbine type information (wind wheel diameter D, wind turbine hub height z hub , wind turbine thrust coefficient C t , and wind turbine power coefficient C p , etc.).

[0104] Step 2: Construct the wind shear curve

[0105] According to the basic law of turbulent motion in the boundary layer, the logarithmic law or the exponential law is used to calculate the inflow wind speed profile u0(z) and the turbulence intensity profile I0(z) considering the wind shear effect:

[0106]

[0107] or

[0108]

[0109] where z is the vertical height, z0 is the roughness height of the ground, z ref is the reference height, when the logarithmic wind profile is applied to the wind power field, the reference height z ref is usually taken as the hub height of the wind turbine z hub , and the corresponding reference wind speed u(z ref ) = U hub , the corresponding reference turbulence intensity I(z ref ) = I hub .

[0110] Step 3: Calculate the wake radius at the x-direction position downstream of the wind turbine :

[0111]

[0112] where x is the x-direction distance between any position downstream of the wind turbine and the position of the wind turbine.

[0113] Step 4: Distribution of turbulence intensity in the wake area of the wind turbine

[0114] (1) First step, calculate the maximum additional turbulence intensity I add, max (x) at the x position in the wake area:

[0115]

[0116] (2) Second step, calculate the additional turbulence intensity I add (x, y, z) at the position (x, y, z) in the wake:

[0117]

[0118] where R is the radius of the wind turbine, is the wake radius, is the distance between any position (x, y, z) and the center point (x , , ) of its x-section, and y, z are the x-direction and vertical direction coordinates respectively.

[0119] (3) Third step, calculate the suppression turbulence intensity of the wind turbine wake :

[0120]

[0121] (4) Fourth step, calculate the x-direction turbulence intensity :

[0122]

[0123] Step 5: Calculate the wind speed profile of each unit and the inflow and wake characteristics

[0124] (1) First step, determine the wind turbine wake area through the wake radius r x and the radial radius r with the wind wheel center line as the center, then calculate the average wake velocity u * (x, z) of the wake area at the vertical direction height z position of the wind turbine downstream x distance, which is used as the initial prediction speed, and its expression is similar to the downstream wake velocity of the classic Jensen model high hat distribution, which is:

[0125]

[0126] In the formula: s - the dimensionless downstream position of the wind turbine wake area, where D is the diameter of the wind wheel; k x,z - the modified wake expansion coefficient considering the environmental turbulence intensity and additional turbulence intensity at the downstream x distance and height z position of the wind turbine, which is calculated by the following formula:

[0127]

[0128] In the formula: I wake,x,z - the effective turbulence intensity at the downstream x distance and height z position of the wind turbine, which is calculated by the following formula:

[0129]

[0130] In the formula: I add,x - the additional turbulence intensity at the x position of the wake area, which is expressed as:

[0131]

[0132] (2) Second step, calculate the wake velocity u(x, y, z) of each unit in the field area. Define the wind speed distribution function f x,r , and the cosine type discrete distribution of the downstream x position wake velocity is:

[0133]

[0134] Further combined with the inflow wind speed profile u0(z), the average wake velocity u * (x, z) and the wind speed distribution function f x,r , the wind turbine wake velocity u(x, y, z) is obtained:

[0135]

[0136] (3) The third step is to consider the influence of multiple wind turbines in the field area (the layout position information and the hub center height difference of each turbine), and to calculate the mixed wake of each turbine in the wind farm based on the single wake of each turbine calculated in the second step above, combined with the wake superposition model to obtain the velocity distribution in the field area. The root sum of squares (RSS) model is used to calculate the superposition wake effect of each turbine:

[0137]

[0138] In the formula, u is the wind speed at any position in the field area, u0 is the inflow wind speed at the corresponding height, u i is the wake speed of each single turbine at the corresponding position (calculated in the second step above, the wind speed at the position not in the wake area of the turbine is consistent with the inflow wind speed), and n represents the number of wind turbines in the field area.

[0139] Referring to Figures 4-10 , the wind speed profile along the tower height and the inflow and wake edge turbulence intensity profile of each hybrid tower wind turbine are calculated by the above calculation method, and the distribution is shown in Figures 4-10 , where the horizontal coordinate u is the wind speed, and T1 is the turbulence intensity. From the ground to about 300 meters in the air, it completely covers the space range where the tower is located. Figures 4-10 The horizontal line in represents the height of the hub center, and the space below the position is the tower. In addition, in order to reflect the influence of the wake on the surrounding turbines, the incoming flow wind resources and the wind resource distribution after being disturbed are also given. Through calculation, the wind resource characteristics of the 7 hybrid towers in the wind farm are as follows:

[0140] (1) #1, #3, #4, and #5 turbines are greatly affected by the wake and local topography, and the wind environment is slightly poor, the load non-uniformity and strength are slightly large, and attention should be paid.

[0141] (2) #6 and #7 turbines basically experience free flow, and the wind environment is mild, and one of them can be selected as a comparative sample.

[0142] (3) Under the condition of the dominant wind direction, #4, #5, and #7 turbines are surrounded by sparse forests, and the incoming flow turbulence intensity may be higher than the results given by the anemometer tower and the weather station.

[0143] In addition, #4 turbine is located in the wake convergence core area, and its structural damage probability is much larger than that of other turbines. Therefore, in this monitoring design, #4 turbine is selected as the core main machine position of the "1+N" monitoring system, and full-module sensors are deployed; #1, #3, #5, and #7 turbines are distributed monitoring turbines, and corresponding sensors are distributed for wind wheel blades, anchor cables, tower body vibration, and concrete cracking.

[0144] Further, in order to formulate a strict monitoring scheme, provide a benchmark for high-precision and comprehensive health protection of the hybrid tower wind power cluster. A high-precision numerical analysis model of the hybrid tower wind turbine is established, and a comprehensive structural mechanics response analysis is carried out. At this time, corresponding to the strain of the wind wheel blade, the prestressed steel strand, the hybrid tower structure, the anchor cable meter, the vibration, the tower top displacement, the inclination, the crack, the foundation settlement monitoring positioning and distribution, the following calculation methods need to be combined:

[0145] Step 1: High-precision modeling of the finite element analysis model of the hybrid tower wind turbine

[0146] Reference Figure 11 The tail vortex of the wind turbine is simplified as a closed vortex ring, the tower cylinder is simplified as a cylinder, the foundation is simplified as a round pier, and the cabin is simplified as a mass block. A multi-body dynamics vibration analysis model of the wind turbine blade (three blades)-tower cylinder-foundation multi-steel structure is established by using the coupling multi-body dynamics method. Based on the extended Hellinger-Reissner variational principle, the motion equation of the whole machine dynamics model is derived, and the rigid connection or spring damping system is used between the blade-cabin, cabin-tower, tower connection section and tower and foundation, respectively. A multi-body dynamics model of the wind turbine considering geometric nonlinearity is established. Specific implementation is as follows:

[0147] (1) The hybrid tower is the core of modeling. First, draw the cross-sectional shape of the hybrid tower section in the drawing software (such as CAD), including the inner and outer diameters and the division lines of the ring pieces, then rotate the cross section around the center axis by 360° to generate the solid model of the ring piece. For the segmented ring section, multiple independent entities need to be generated according to the division lines. Steel tower section, anchor, steel flange and steel gasket need to be modeled separately, and the connection surface with the hybrid tower section needs to be matched. In the selection of unit type, the concrete tower section, steel tower section, foundation, steel flange and steel gasket adopt three-dimensional eight-node hexahedral linear reduced integration (C3D8R) unit, and ordinary steel bar and prestressed steel strand adopt two-node linear beam (B31) unit. In the simulation process, all components are divided into structural mesh to ensure calculation accuracy and efficiency. The hybrid tower section adopts C65 concrete, and in order to accurately simulate the nonlinear mechanical behavior of concrete, the concrete damaged plasticity (CDP) in the Abaqus analysis software is used.

[0148] Further, the prestress of the hybrid tower is applied by using the cooling method, that is, the corresponding part is cooled first to make the part shrink, and then the part is fixed to make the concrete tower obtain prestress. The theoretical cooling value calculation formula in the cooling method is:

[0149]

[0150] In the formula, — prestressed target value, - the modulus of elasticity of the respective component, - the coefficient of linear expansion of the respective component.

[0151] (2) Wind turbine blade. According to the basic information of the reference wind turbine blade design, such as the geometry, material, and structural layup, a finite element model of the wind turbine blade is established by shell element structure.

[0152] (3) Complete machine model. Three blades are connected by a rigid hub based on the pitch angle and cone angle to form a complete wind wheel, and then the wind wheel is assembled with the tower through a rigid chassis. The weight of the hub and the nacelle is placed at the center of gravity in the form of point mass, and the finite element model is assembled by shell element-solid element coupling wind turbine generator.

[0153] Step 2: Analysis of the mechanical properties of the ultra-high hybrid tower wind turbine

[0154] Reference Figures 12-15 For the main parts of the hybrid tower wind turbine, such as the foundation, hybrid tower structure, and prestressed steel strand of the tower, harmonic response analysis and transient response analysis are performed. The static and dynamic characteristics of the hybrid tower under wind load and the displacement response caused by the rotation of the wind wheel are studied, and the dynamic response of each main part of the hybrid tower under different frequencies is obtained, as well as the structural deformation and stress corresponding to the peak frequency. Considering the influence of variable pitch angle under different wind speeds, the displacement, velocity, and acceleration of each main part of the hybrid tower at each time are calculated, and the stress of the dangerous points of the tower bottom, tower joint, and tower connecting section is studied, as well as the relationship between the displacement of the tower top and the related parameters. Through analysis, it is found that:

[0155] (1) Figure 12 The stress distribution of the tower, the stress discontinuity phenomenon at the steel-concrete transition, and the maximum stress at the top of the tower, so the displacement sensors should be deployed at the top of the tower and the steel-concrete transition to monitor the stress and displacement of the mechanical properties.

[0156] (2) Figure 13 The displacement, acceleration, and velocity distribution of the tower top, the dynamic characteristics of the tower top present obvious fluctuations with the action time of dynamic load, and there is a certain fluctuation in the pitch angle of the tower top, so the acceleration sensor should be deployed on the tower body to closely monitor the vibration characteristics of the tower body and the inclination characteristics of the tower top and the steel-concrete transition.

[0157] (3) Figure 14 The strain distribution of the hybrid tower, the concrete section, and the steel-concrete transition, there are areas with large deformation near the door frame, different tower sections, and the steel-concrete transition in the concrete section, so crack meters should be deployed in the concrete section to monitor the deformation.

[0158] (4) Figure 15The prestress distribution of the prestressed tendon of the hybrid tower, the stability of the prestress and whether there is loss are crucial to the safety of the high-rise structure, so the anchor cable is arranged to monitor the tension of the prestressed anchor cable.

[0159] (5) Further, the blade root load of the wind rotor blade is a load convergence zone, and the strict control of whether the blade load is over-limit can be realized through the strain sensor, so the strain gauge is arranged at the root of the wind rotor blade to realize the accurate capture of the operating load of the blade.

[0160] (6) For high-rise structures, the settlement monitoring of the tower body and the foundation can reflect the operation safety of the whole machine.

[0161] Reference Figure 16 The #4 unit is the core host of the omnidirectional sensor deployment, and 7 types of sensors are deployed in the key bearing structure of the hybrid tower. This includes wind rotor blade-mounted strain gauges that capture real-time aerodynamic loads, prestressed steel strand anchor cable gauges that monitor tension force decay, tower top GNSS and dynamic inclinometer synchronous tracking displacement-inclination coupling deformation, tower cylinder concrete crack evolution quantified by joint metering, foundation settlement sensed by static leveling instrument, and vibration state monitored by tower cylinder accelerometer in full frequency band. This host site integrates heterogeneous sensor clusters to form a closed-loop monitoring of the interaction between the wind rotor blade, tower structure, foundation, and prestressed steel strand, providing a benchmark for high-precision, comprehensive health protection for the cluster. At this time, corresponding to the strain of the wind rotor blade, the prestressed steel strand, the hybrid tower structure, the anchor cable gauge, the vibration, the tower top displacement, the inclination, the crack, the foundation settlement monitoring positioning and distribution, the following calculation methods need to be combined:

[0162] Secondly, directional and simplified monitoring is implemented on the subunit: the #7 unit focuses on wind rotor blade strain, the #3 unit specializes in anchor cable tension, the #5 unit monitors hybrid tower vibration, and the #1 unit locks concrete crack expansion. At this time, the monitoring strategy of each distributed unit forms a "deep monitoring + edge modular simplification" mode with the #4 wind turbine, achieving a precise balance between risk targeting and economy for the hybrid tower wind power cluster of the wind farm.

[0163] Reference Figure 17 The omnidirectional monitoring design of the #4 unit is as follows:

[0164] First, for the wind rotor blade, 4 dynamic surface strain gauges (2 in the horizontal direction and 2 in the vertical direction) are installed at 1.5 meters apart on each wind rotor blade root section, a total of 12 dynamic surface strain gauges, for local dynamic strain monitoring. The strain gauge is pasted on the inside surface of the blade root. When the blade deforms under stress, the strain gauge stretches or compresses, and its resistance value changes. By measuring the resistance change through the measurement circuit and converting it into strain value output, the dynamic strain on the blade surface can be monitored in real time to evaluate the blade stress state and safety.

[0165] Secondly, in view of the cable force, the anchor cable state of all prestressed steel strands of the No. 4 unit is detected by a handheld cable force gauge, and four orthogonal prestressed steel strands are selected according to the cable force deviation of all anchor cable states. The installation direction of the anchor cable gauge is the axis of the main wind direction of the wind power hybrid tower, the installation platform is the tower section, one anchor cable is selected at each end of the intersection of the axis and the tower, and the other anchor cable is selected at each end of the intersection of the vertical line perpendicular to the main wind direction axis and the tower. The specific installation needs to be determined in combination with the actual situation on site. Two anchor cable gauges are installed at each end of the intersection of the axis and the tower, and the other two are installed at each end of the intersection of the vertical line perpendicular to the main wind direction axis and the tower.

[0166] Then, in view of the hybrid tower vibration, accelerometers, GNSS and inclinometers are distributed and deployed. The specific implementation steps are:

[0167] (1) Accelerometer. Along the main wind direction and perpendicular to the main wind direction, 2 two-way acceleration sensors are deployed at the tower top, the tower section 80 m and 50 m away from the tower bottom, respectively, a total of 6; 4 two-way acceleration sensors are deployed at the steel-mix transition area, the tower section 20 m away from the tower bottom, respectively, a total of 8; a total of 14 accelerometers. Thus, efficient vibration monitoring of the hybrid tower cylinder acceleration and mode shape can be realized.

[0168] (2) GNSS. GNSS is installed outside the tower top nacelle, and is positioned by using the Beidou satellite system. The terminal obtains the three-dimensional coordinates of the tower top in real time, which are transmitted to the cloud server through wireless communication. The cloud server compares the coordinates at different times, calculates the spatial displacement of the tower top, and thus realizes real-time monitoring of the displacement of the wind power tower, providing a basis for safety assessment.

[0169] (3) Inclinometer. One dynamic two-axis inclinometer is installed at the tower top platform and the steel-mix transition area, respectively, and the installation position is at the main wind direction of each section, a total of 2, realizing real-time monitoring of the inclination state of the hybrid tower body.

[0170] Finally, in view of the hybrid tower cracking, joint meters and static leveling instruments are deployed respectively. The specific implementation steps are:

[0171] (1) Joint meter. When monitoring the concrete cracks of the wind power hybrid tower cylinder, the first installation focuses on the basic layout of the key parts, two joint meters are installed at the steel-mix joint to monitor the opening degree, and two joint meters are installed at the vertical joint of the first concrete tile below the steel-mix joint to monitor the hybrid tower cracking, a total of 4, to build a preliminary monitoring framework and capture subtle changes in real time. In the second installation stage, in view of the new situation that the hybrid segment has cracks, the original equipment installed in the hybrid segment is removed and accurately reinstalled at the crack to enhance the pertinence and effectiveness of the monitoring, so as to timely grasp the crack development trend and ensure the safe and stable operation of the wind power hybrid tower cylinder.

[0172] (2) Static level gauge. On the foundation platform, install 3 static level gauges in an equilateral triangle with the main wind direction as the vertex, and use the liquid level characteristics of the communicating vessel to measure the structural height difference changes. If the tower foundation settles or the tower body tilts, the liquid level height of each measuring point changes, and the relative settlement or tilt of the hybrid tower unit is calculated by measuring the liquid level difference with high-precision sensors, thereby realizing long-term automatic monitoring of the uneven settlement of the hybrid tower.

[0173] Referring to Figure 18 , the distributed monitoring of the #7 unit focuses on the wind wheel blades. At 1.5 meters from the root section of each wind wheel blade, install 4 dynamic surface strain gauges (2 in the horizontal direction and 2 in the vertical direction), for a total of 12 dynamic surface strain gauges, for local dynamic strain monitoring.

[0174] Referring to Figure 19 , the distributed monitoring of the #3 unit focuses on the cable force of the hybrid tower. Detect the anchor cable state of all prestressed steel strands of the #3 unit using a handheld cable force gauge, and select 4 orthogonal prestressed steel strands for installation of the anchor cable gauge based on the cable force deviation of all anchor cables. The installation direction of the anchor cable gauge is determined based on the main wind direction of the wind power hybrid tower as the axis, and the installation platform is the tower cylinder cross section. At the intersection of the axis and the tower cylinder, select one anchor cable from each end, and from the center of the cross section, draw a vertical line perpendicular to the main wind direction axis, and select one anchor cable from each end of the intersection with the tower cylinder. The specific installation needs to be determined in combination with the actual site conditions. At the intersection of the axis and the tower cylinder, install two anchor cable gauges, and from the center of the cross section, draw a vertical line perpendicular to the main wind direction axis, and install two more at the intersection with the tower cylinder.

[0175] Referring to Figure 20 , the distributed monitoring of the #5 unit focuses on the vibration of the hybrid tower. The specific implementation steps are as follows:

[0176] (1) Accelerometer. Along the main wind direction and perpendicular to the main wind direction, deploy 2 two-way acceleration sensors at the steel-concrete transition zone and at the tower body cross section 20 meters from the tower bottom, for a total of 4.

[0177] (2) Inclinometer. Install 1 dynamic two-axis inclinometer at the tower top platform and the steel-concrete transition zone, respectively, at the main wind direction of each cross section, for a total of 2.

[0178] Referring to Figure 21 , the distributed monitoring of the #5 unit focuses on the cracking of the hybrid tower. The specific implementation steps are as follows:

[0179] (1) Joint meter. In the steel-concrete transition zone, arrange 1 joint meter in the main wind direction and perpendicular to the main wind direction; install 2 joint meters at the vertical joint of the first concrete tile below the steel-concrete joint. A total of 4.

[0180] (2) Static level gauge. On the foundation platform, install 3 static level gauges in an equilateral triangle with the main wind direction as the vertex.

[0181] The application creatively constructs a full-coupling distributed health monitoring paradigm of the mixed-tower wind power cluster, and realizes three breakthroughs in engineering practice: first, through the "full-coupling distributed" architecture, the wind field wind resource analysis is deeply integrated with the mixed-tower structure monitoring safety, a full-chain collaborative diagnosis network is constructed with the main machine site as the perception center, the multi-physical field coupling effects of the blade aerodynamic load, the tower cylinder dynamic response (vibration and deformation), the tower body inclination, the anchor cable prestress, the concrete crack expansion and the foundation settlement are captured in real time on the engineering scale for the first time, which completely changes the fragmented dilemma of "seeing vibration but not crack, measuring force but not foundation" in traditional monitoring, and provides closed-loop early warning capability for the major engineering problem of multi-structure coupling failure of the mixed-tower wind turbine; second, the distributed resource allocation logic of "main machine site deep perception + sub-machine group targeted focus" is created, the abnormal state of the key structure area of the wind wheel blade, the mixed-tower tower cylinder and the foundation is perceived in all directions by the main machine site, the key bearing structure is targeted by the distributed monitoring machine group, and the 1+N monitoring strategy is linked, so that the monitoring cost of the mixed-tower wind power cluster is transferred from extensive coverage to precise supply, the hardware redundancy is greatly reduced on the premise of ensuring global safety, and the wind power cluster monitoring is transformed from "aristocratization" to "popularization"; third, the whole life cycle management is implanted into the monitoring architecture kernel, the multi-source heterogeneous data fusion of the main machine site and the distributed nodes is formed, the intelligent closed loop of "monitoring-evaluation-decision-optimization" is formed, and the methodological level support is provided for the whole life service of the mixed-tower machine group. The three innovations are closely linked, from the innovation of technical principle to the reconstruction of engineering cost and then to the upgrade of operation and maintenance paradigm, and the safety and economic balance of the wind power industry is systematically remodeled.

[0182] The above embodiments are the preferred embodiments of the application, but the embodiments of the application are not limited by the above embodiments, and any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the application shall be equivalent replacement methods and shall be included in the protection scope of the application.

Claims

1. A method for monitoring a cluster of wind turbines of the omnidirectional coupling distributed super-high hybrid tower type, characterized in that, Comprising the following steps: Step 1, based on the wind field inflow wind resource information and wind turbine parameters, the wind speed profile and turbulence intensity profile of each hybrid tower wind turbine in the field are calculated through the wind resource distribution model, and the single unit most affected by the wake and topography is identified as the core host site; Step 2, on the core host site, all structural modules are deployed with corresponding sensor groups for monitoring, and the structural modules of the hybrid tower wind turbine include wind turbine blades, prestressed steel strands, hybrid tower cylinder vibration, hybrid tower cylinder concrete cracking and foundation settlement structural modules; Step 3, on the remaining distributed units except the core host site, one or more of all structural modules are selected and corresponding sensor groups are deployed for monitoring; Step 4, the monitoring data of the core host site and the distributed units are fused to realize the multi-parameter, multi-module coupling health status evaluation and early warning of the hybrid tower wind turbine cluster.

2. The omni-coupled distributed super-high-rise tower wind turbine cluster monitoring method according to claim 1, characterized in that, In step 1, the wind farm inflow wind resource information includes: the inflow wind speed U at the hub height position of the wind turbine hub and the turbulence intensity I hub , the ground roughness z0 and the exponential wind profile parameter a; the wind turbine parameters include the longitude and latitude coordinates or relative positions (x wake , y wake , z wake ) of each unit, the wind wheel diameter D, the hub height z hub of the wind turbine and the thrust coefficient C t and the power coefficient C p of the wind turbine.

3. The omni-coupled distributed super-high-rise tower wind turbine cluster monitoring method according to claim 2, characterized in that, In step 1, the specific method for identifying the single unit most affected by the wake and topography as the core host site by calculating the wind speed profile and turbulence intensity profile of each hybrid tower wind turbine in the field through the wind resource distribution model is as follows: Step 11, construct the wind shear curve: According to the basic law of turbulent motion in the boundary layer, the logarithmic law or exponential law is used to calculate the inflow wind speed profile u0(z) and turbulence intensity profile I0(z) considering the wind shear effect: ； Or ； wherein: z is the vertical height; z0 is the surface roughness height; z ref is the reference height, when the logarithmic wind profile is applied to the field of wind power, the reference height z ref is taken as the height of the hub of the wind turbine z hub , at this time the corresponding reference wind speed u(z ref ) = U hub , the corresponding reference turbulence intensity I(z ref ) = I hub ; Step 12, calculating the wake radius at the x-streamwise position downstream of the wind turbine : ； wherein R is the rotor radius, x is the streamwise distance from any position downstream of the wind turbine to the position of the rotor. Step 13, calculate the turbulence intensity distribution in the wake area of the unit: Step 131, calculate the maximum additional turbulence intensity I at the x position of the wake region add, max (x): ； Step 132, calculate the additional turbulence intensity I at the wake (x, y, z) add (x, y, z): ； wherein the distance of any position (x, y, z) in space to the center point (x, , ) of its x-section, y, z are the coordinates in crosswind and vertical direction, respectively, Step 133, calculating a turbulence suppression intensity of the wind turbine wake : ； Step 134, calculate flow to turbulence intensity : ； Step 135, calculate the wind speed profile and inflow and wake characteristics of each unit: (1) The wake region of the wind turbine is determined by the wake radius r x and the radial radius r with the center line of the wind wheel as the center. The average wake velocity u * (x, z) of the position wake region at the vertical direction height z of the downstream x distance of the wind turbine is calculated, which is the initial prediction speed, and its expression is: ； where s is the non-dimensionalized downstream position of the wind turbine wake region, ; k x,z is the modified wake expansion coefficient accounting for the influence of the ambient turbulence intensity and the additional turbulence intensity at a downstream x distance and height z position of the wind turbine and is calculated by the following equation: ； where: I wake,x,z is the effective turbulence intensity at a downstream x distance, height z position of the wind turbine, calculated by the following equation: ； where: I add,x The additional turbulence intensity for the wake region x position is expressed as: ； (2) Calculate the velocity u(x, y, z) of the wake zone of each unit in the field area, and define the wind speed distribution function f x,r Discrete cosine distribution of the wake velocity at the downstream x position: ； and combined with the inflow wind velocity profile u0(z), the mean wake velocity u * (x, z) and the wind speed distribution function f x,r The wind turbine wake zone velocity u(x, y, z) is obtained: ； (3) Considering the influence of multiple wind turbines in the field, based on the single wake area velocity u(x, y, z) calculated in step (2), the velocity distribution in the field is obtained, and the square root sum model is used to calculate the superposition wake effect of each unit: ； where u is the wind speed at any location in the field, u0 is the inflow wind speed at the corresponding height, u i is the wake velocity of each individual unit at the corresponding location, and n represents the number of wind turbines in the field. Step 136, through the calculation method of steps 131-135, the wind speed profile and turbulence intensity profile of each hybrid tower wind turbine are calculated, the influence of the wake of each hybrid tower wind turbine is identified, and the single unit most affected by the wake and topography is selected as the core host site in combination with the topography of each hybrid tower wind turbine.

4. The omni-coupled distributed super-high-rise tower wind turbine cluster monitoring method according to claim 3, characterized in that, In step 2, the sensors corresponding to the wind turbine blade module are dynamic surface strain gauges, the sensors corresponding to the prestressed steel strand module are anchor cable gauges, the sensors corresponding to the hybrid tower cylinder vibration module are accelerometers, GNSS and inclinometers, and the sensors corresponding to the hybrid tower cylinder concrete cracking and foundation settlement structural module are joint meters and static leveling instruments.

5. The omnidirectional coupling distributed super-high hybrid tower wind turbine cluster monitoring method according to claim 4, characterized in that, For the wind turbine blade module: multiple dynamic surface strain gauges are arranged at the root section of each wind turbine blade; For the prestressed steel strand module: at least four orthogonal steel strands are selected and anchor cable gauges are installed according to the cable force deviation of all prestressed steel strands; For the hybrid tower cylinder vibration module: two-way accelerometers are deployed at the steel-concrete transition area and one or more key sections along the tower height, and inclinometers are installed at the tower top platform and / or steel-concrete transition area; For the structure module of concrete cracking and foundation settlement of the mixed tower, joint meters are arranged at the vertical joints of the steel-concrete transition zone and the concrete section, and static leveling instruments are arranged on the foundation platform.

6. The omni-coupled distributed super-high-rise tower wind turbine cluster monitoring method according to claim 1, wherein, In step 4, the monitoring data of the fusion core host and the distributed unit are fused to realize the specific method of multi-parameter and multi-module coupling health state evaluation and early warning of the mixed tower wind turbine cluster: Step 41: finite element analysis modeling of the mixed tower wind turbine: The tail vortex of the wind turbine is simplified as a closed vortex ring, the tower drum is simplified as a cylinder, the foundation is simplified as a round pier, and the nacelle is simplified as a mass block. A coupled multi-body dynamics method is used to establish a multi-steel structure dynamic vibration analysis model of the wind turbine blade-tower drum-foundation. Based on the extended Hellinger-Reissner variational principle, the motion equation of the whole machine dynamic model is derived. The rigid connection or spring damping system is used between the blade-nacelle, nacelle-tower drum, tower drum connecting section, and tower drum and foundation, respectively. A wind turbine multi-body dynamics model considering geometric nonlinearity is established. The specific implementation is: (1) The mixed tower is the core of modeling. First, draw the cross-sectional shape of the mixed tower section in the drawing software, including the inner and outer diameters and the division lines of the ring pieces. Then rotate the cross section around the center axis by 360° to generate the solid model of the ring pieces. For the segmented ring section, multiple independent entities need to be generated according to the division lines. The steel tower section, anchor, steel flange and steel gasket need to be modeled separately and ensure that the connection surfaces match the mixed tower section. In the selection of unit type, the concrete tower section, steel tower section, foundation, steel flange and steel gasket adopt three-dimensional eight-node hexahedral linear reduced integration element, and ordinary steel bar and prestressed steel strand adopt two-node linear beam element. In the simulation process, all components are divided into structural grids. The mixed tower section uses C65 concrete and the Abaqus analysis software uses concrete damage plasticity. The prestress of the mixed tower is applied by the cooling method, i.e. first cool the corresponding part to make it shrink, then fix the part to make the concrete tower obtain prestress, (2) According to the geometric shape, material and structural layer information of the reference wind turbine blade design, a shell element structure wind turbine blade finite element model is established, (3) The blade is connected by a rigid hub based on the elevation angle and taper angle to form a complete wind wheel, and then the wind wheel is assembled with the tower drum through a rigid chassis. The hub weight and nacelle weight are placed at the respective center of gravity positions in the form of point mass. Shell element-solid element coupling wind turbine finite element is used to assemble the finite element model; Step 42: analysis of the mechanical properties of the ultra-high mixed tower wind turbine: The harmonic response analysis and the transient response analysis are performed on the foundation, the hybrid tower structure and the prestressed steel strand part of the tower drum of the hybrid tower wind turbine, the static and dynamic characteristics of the hybrid tower under the wind load and the displacement response caused by the rotation of the wind wheel are obtained, the dynamic response of each main part of the hybrid tower under different frequencies is obtained, and the structural deformation and stress corresponding to the peak frequency are obtained; considering the influence of the variable pitch angle under different wind speeds, the displacement, velocity and acceleration of each main part of the hybrid tower at each time are calculated, the stress of the dangerous points of the bottom of the tower drum, the tower drum joint seam and the tower drum connecting section, and the relationship between the displacement and related parameters of the top of the tower drum and the steel-mixing connection are obtained, and then the health state evaluation of each hybrid tower wind turbine is realized, and according to the health state evaluation result, the state of the hybrid tower wind turbine is warned.

7. A full-coupling distributed super-high hybrid tower wind turbine cluster monitoring system for implementing the full-coupling distributed super-high hybrid tower wind turbine cluster monitoring method according to any one of claims 1-6, characterized in that, It comprises a wind resource analysis module, a sensor network, a data acquisition and transmission module, and a data fusion and health evaluation module, wherein the wind resource analysis module, the sensor network, and the data acquisition and transmission module are respectively connected with the data fusion and health evaluation module. The wind resource analysis module is used to perform the wind resource analysis and core host site identification steps. The sensor network comprises an all-around sensor group deployed at the core host site and a targeted sensor group deployed at the distributed generator. The data acquisition and transmission module is used to acquire and transmit the data of the sensor network. The data fusion and health evaluation module is used to perform the data fusion and health evaluation steps.

8. A computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method of any one of claims 1-6. ​

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