Wind power plant evaluation device and wind power system

Abstract

The present invention provides a wind power plant evaluation device and a wind power generation system that can evaluate damage to floating wind power plants subjected to loads from natural phenomena such as wind, waves, and ocean currents. [Solution] According to one embodiment, the wind power plant evaluation device includes a signal receiving unit that receives input of acceleration at a first measurement point and tension at a second measurement point when a wave load acts on the wind power plant. Furthermore, the wind power plant evaluation device includes a displacement calculation unit that uses time-series data of acceleration to calculate the displacement at the first measurement point when a wave load acts on the wind power plant. Furthermore, the wind power plant evaluation device includes a response load estimation unit that estimates the wave load acting on the floating body of the wind power plant based on acceleration, displacement, and tension. Furthermore, the wind power plant evaluation device includes a damage evaluation unit that evaluates damage to the wind power plant.

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a wind power plant evaluation device and a wind power system. [Background technology]

[0002] Floating wind power plants located on the ocean may be subjected to loads from natural phenomena such as wind, waves, and ocean currents that exceed expectations. Therefore, it is necessary to understand the extent of damage due to fatigue and other factors to the plant structures, and to plan and implement appropriate maintenance and repairs in order to ensure the stable operation of the plant. As a general method for evaluating damage to wind power plants, a method has been proposed that evaluates damage to blades, towers, etc., caused by wind by acquiring signals from strain gauges and other devices. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 6674031 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the above method requires the installation of numerous strain gauges on floating structures, such as floating wind power plants, which are subjected to wave loads from waves and ocean currents. Therefore, particularly in large-scale wind power plants, significant costs are incurred for the installation and maintenance of these strain gauges.

[0005] Therefore, this embodiment of the present invention provides a wind power plant evaluation device and a wind power generation system that can evaluate damage to a floating wind power plant subjected to loads from natural phenomena such as wind, waves, and ocean currents. [Means for solving the problem]

[0006] According to one embodiment, the wind power plant evaluation device includes a signal receiving unit that receives input of acceleration at a first measurement point and tension at a second measurement point when a wave load acts on the wind power plant. Furthermore, the wind power plant evaluation device includes a displacement calculation unit that uses time-series data of acceleration to calculate the displacement at the first measurement point when a wave load acts on the wind power plant. Furthermore, the wind power plant evaluation device includes a response load estimation unit that estimates the wave load acting on the floating body of the wind power plant based on acceleration, displacement, and tension. Furthermore, the wind power plant evaluation device includes a damage evaluation unit that evaluates damage to the wind power plant. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of the wind power generation system in the first embodiment. [Figure 2] This is another schematic diagram of the wind power generation system in the first embodiment. [Figure 3] This is a diagram showing the detailed configuration of the wind power generation system in the first embodiment. [Figure 4] This is an example of a flowchart for a wind power generation system in the first embodiment. [Figure 5] This is a hardware configuration diagram of the wind power plant evaluation device in the first embodiment. [Figure 6] This figure shows the detailed configuration of the wind power generation system in the second embodiment. [Figure 7] This is an example of a flowchart for a wind power generation system in the second embodiment. [Figure 8] This figure shows the detailed configuration of the wind power generation system in the third embodiment. [Figure 9] This is a flowchart of the wind power generation system in the third embodiment. [Figure 10] This figure shows the detailed configuration of the wind power generation system in the fourth embodiment. [Figure 11] This is a flowchart of the wind power generation system in the fourth embodiment. [Modes for carrying out the invention]

[0008] (First Embodiment) Embodiments of this disclosure will be described below with reference to the drawings. These embodiments are not intended to limit the present invention. The drawings are schematic or conceptual, and the proportions of each part may not necessarily be the same as those of actual objects. In the specification and drawings, elements similar to those described above with respect to previously shown drawings are denoted by the same reference numerals, and detailed descriptions are omitted as appropriate.

[0009] Furthermore, the X, Y, and Z axes described below represent mutually orthogonal axes, with the Z direction being the direction of gravity, and the X and Y directions being in a horizontal plane perpendicular to the direction of gravity. Also, the +Z direction corresponds to the upward direction, and the -Z direction corresponds to the downward direction. As an example, the +X direction corresponds to the forward direction, and the -X direction corresponds to the backward direction. Also, the +Y direction corresponds to the right direction, and the -Y direction corresponds to the left direction. The forward and backward directions may be reversed, and the right and left directions may be reversed. The X direction is an example of the first direction, the Y direction is an example of the second direction, and the Z direction is an example of the third direction.

[0010] Furthermore, in the following embodiments, the terms "greater than or equal to" and "less than or equal to" can be replaced with "greater than" and "less than," respectively.

[0011] Furthermore, the first to fifth measurement points of each measuring instrument described in the following embodiments may be different measurement points, or they may overlap in some or all ways.

[0012] Figure 1 is a schematic diagram of the wind power generation system 100 in the first embodiment.

[0013] The wind power generation system 100 in this embodiment includes a wind power plant 10, a wind power plant evaluation device 6, and various measuring instruments installed in the wind power plant 10. This figure shows a portion of the wind power plant 10 to illustrate the general configuration of the wind power generation system 100; the detailed configuration will be described later.

[0014] Generally, wind power plants 10 located on the ocean are subjected to loads (wave loads) from natural phenomena such as wind, waves, and ocean currents. Therefore, wind power plants 10 can be damaged due to fatigue caused by wave loads.

[0015] In this embodiment, the wind power plant evaluation device 6 evaluates damage caused by wave loads using data from various measuring instruments installed on a floating wind power plant 10. In this figure, an example is shown where the wind power plant evaluation device 6 is located inside the nacelle 12 of the wind power plant 10, and the wind power plant evaluation device 6 uses measuring instrument data transmitted via the communication network 5a. The evaluation results can be checked inside the nacelle 12, and are also transmitted via the communication network 5b to onshore facilities 200 such as offshore substations and control centers, and can be checked by the user via the display device 50.

[0016] In this embodiment, the measurement data acquired by the measuring instrument installed in the wind power plant 10 (in this figure, an acceleration measuring instrument 41 mounted on the outside of the nacelle 12 of the wind turbine 1 is shown as an example) is received by the receiver 5c installed inside the nacelle 12. Furthermore, this data is transmitted to the wind power plant evaluation device 6 using the network device 5d.

[0017] The wind power plant evaluation device 6 evaluates damage caused by wave loads based on received instrument data. Because the load on the mooring ropes 3 changes significantly due to the swaying of the floating body 2, the wind power plant evaluation device 6 evaluates damage including the tension acting on the mooring ropes 3, i.e., the load on the mooring ropes 3. The evaluation results are displayed on a display device (not shown) installed inside the nacelle 12 and also transmitted via a communication network 5b established between the wind power plant 10 and the onshore facilities 200.

[0018] The communication network 5a used here may be a wireless network such as a 4G (4th generation) network or a 5G (5th generation) network. The communication network 5a may also use a wireless network of Wi-Fi (registered trademark) or other standards.

[0019] Furthermore, the communication network 5b may be a wired line such as an optical communication line, or it may be a wireless line such as a 4G line, a 5G line, or a satellite wireless line. These may also be combined to create a redundant network. Various network devices 5d are used, tailored to the configuration of the communication network 5b.

[0020] Figure 2 is another schematic diagram of the wind power generation system 100 in the first embodiment.

[0021] In this embodiment, the wind power plant evaluation device 6 is installed on the onshore facility 200, rather than inside the nacelle 12. Measurement data installed on the wind power plant 10 is received by the receiver 5c, then transmitted to the network device 5d, and then transmitted to the wind power plant evaluation device 6 on the onshore facility 200 via the communication network 5b.

[0022] After the instrument data is transmitted to the wind power plant evaluation device 6, the damage status of the wind power plant is evaluated in the same manner as in the configuration shown in Figure 1. Figure 2 shows an example where the wind power plant evaluation device 6 is installed in a location such as an offshore substation or control center, but the wind power plant evaluation device 6 may also be installed in a data center (not shown) and operate as a cloud server. In the following example, the wind power plant evaluation device 6 will be described using the configuration shown in Figure 1.

[0023] Figure 3 shows a detailed configuration of the wind power generation system 100 in the first embodiment.

[0024] This diagram shows the wind power generation system 100, mainly illustrating the detailed configuration of the wind power plant 10 and the block diagram of the wind power plant evaluation device 6.

[0025] The wind power plant 10 comprises a wind turbine 1, a floating structure 2, and mooring ropes 3.

[0026] Wind turbine 1 is a device that generates electricity using wind power. As shown in Figure 3, wind turbine 1 comprises a nacelle 12, a tower 14, a rotor 15, and a generator (not shown). The nacelle 12 and rotor 15 together are also called RNA (rotor-nacelle assembly).

[0027] The tower 14 supports the nacelle 12 from below. The tower 14 is formed as a slender column extending vertically. The nacelle 12 functions as a housing. The nacelle 12 houses the rotor 15's rotation shaft, the gearbox, and the generator (not shown). The nacelle 12 is configured to rotate in the yaw direction relative to the tower 14. The nacelle 12 also rotatably supports the rotor 15. The rotor 15 includes a plurality of blades 11, a hub 13, and a rotation shaft (not shown). The plurality of blades 11 and the hub 13 are located in front of the nacelle 12. The hub 13 supports the plurality of blades 11. The plurality of blades 11 are arranged radially around the hub 13. One end of the rotation shaft is connected to the hub 13, and the other end is connected to the gearbox. The rotation shaft is connected to the generator via the gearbox.

[0028] The blades 11 rotate due to wind power, generating rotational energy. More specifically, the blades 11 rotate together with the hub 13 and the rotating shaft, converting the fluid energy obtained from the wind power into rotational energy. The rotating shaft transmits the rotational energy generated by the blades 11 to the generator. More specifically, the rotational energy is transmitted to the generator by the rotating shaft via a speed control mechanism. The speed control mechanism increases the rotational speed and transmits the rotation to the generator. Alternatively, the rotation may be transmitted directly to the generator without going through a speed control mechanism, as in a direct drive system. The generator uses the transmitted rotational energy to generate electricity. In this way, the wind turbine 1 generates electricity using wind power.

[0029] The floating body 2 is a structure that supports the wind turbine 1 on the ocean surface by buoyancy. As shown in Figure 3, the floating body 2 has multiple columns 21 and connecting parts 22.

[0030] Column 21 is formed in an elongated column shape extending vertically. Column 21 has a cavity inside. At least a portion of Column 21 is submerged in the sea, and this cavity generates buoyancy. Connecting section 22 connects multiple columns 21 to each other. Tower 14 is connected to one of the multiple columns 21. As a result, the multiple columns 21 generate buoyancy and support the wind turbine 1 on the ocean. Connecting section 22 includes braces or pontoons. Note that the connecting section 22 may also have a cavity inside, which generates buoyancy. Footing 23 may be provided at the bottom of Column 21. Mooring lines 3 may also be connected to the footing 23. The floating body 2 is moored to the seabed via the mooring lines 3. As a result, the wind power plant 10 remains in a predetermined area of ​​the sea. In this diagram, two types of mooring ropes 3 are shown: catenary mooring 31 and tension mooring 32. However, in a wind power plant 10, typically only one of these mooring ropes 3 is used.

[0031] Furthermore, measuring instruments are installed at each measurement point in the wind power plant 10. In this example, we will consider an example in which an accelerometer 41 and a tension meter 42 are installed as measuring instruments.

[0032] The accelerometer 41 is installed at one or more measurement points in the wind power plant 10. The accelerometer 41 is configured to measure acceleration a. The accelerometer 41 is, for example, an acceleration sensor. The accelerometer 41 measures the acceleration at the measurement points when wave loads act on the wind power plant 10, mainly the wind turbine 1 and the floating body 2. The accelerometer 41 is installed at the measurement points of the wind turbine 1 and the floating body 2, respectively. The accelerometer 41 is installed at multiple measurement points, such as the tower 14 and nacelle 12 of the wind turbine 1 and the column 21 of the floating body 2, so that surge, sway, heave, roll, pitch, and yaw motions caused by the oscillation of the wind power plant 10 can be measured. The accelerometer 41 measures the vibrations when wave loads act on the wind power plant 10 as time-series data of acceleration a. The accelerometer 41 may be a three-dimensional accelerometer that measures acceleration in a total of three directions: two horizontal directions and one vertical direction. In this case, the acceleration a due to roll, pitch, and yaw motions is calculated from the measurement data of multiple accelerometers 41. The measurement points of the accelerometer 41 (for example, the wind turbine 1 and the floating body 2) are also called the first measurement points.

[0033] Furthermore, it is desirable that the acceleration measuring instruments 41 be installed, for example, in the front, back, left, right, and top and bottom of the wind turbine 1 and the floating body 2, so that rotation in the front-to-back direction, rotation in the left-to-right direction, and rotation around the vertical axis can be measured.

[0034] The tension measuring device 42 is installed at one or more measurement points on the mooring rope 3. The load on the mooring rope 3 changes significantly due to the oscillation of the floating body 2 when a wave load is applied. The tension measuring device 42 is configured to measure the tension acting on the mooring rope 3, that is, the load acting on the mooring rope 3. The tension measuring device 42 is, for example, a tension sensor or a load sensor. The tension measuring device 42 measures the tension acting on the mooring rope 3 when a wave load is applied to the floating body 2. The tension measuring device 42 is configured to measure the change in tension due to the oscillation of the mooring rope 3. In this embodiment, the tension measuring device 42 is installed on the catenary mooring 31 and tension mooring 32. The tension measuring device 42 measures the value of the tension acting on the mooring rope 3 due to the wave load as time-series data. The measurement point (mooring rope 3, etc.) by the tension measuring device 42 is also called the second measurement point.

[0035] The wind power plant evaluation device 6 includes a signal receiving unit 61, a displacement calculation unit 62, a response load estimation unit 63, a wave height estimation unit 64, a time history response calculation unit 65, a damage evaluation unit 66, a database 67, and a display unit 68.

[0036] The wind power plant evaluation device 6 can be realized, for example, by installing a program for the wind power plant evaluation device 6 on a PC (Personal Computer). The CPU (Central Processing Unit) within the wind power plant evaluation device 6 executes the program for the wind power plant evaluation device 6, thereby realizing the functions of the signal receiving unit 61, displacement calculation unit 62, response load estimation unit 63, wave height estimation unit 64, time history response calculation unit 65, damage evaluation unit 66, database 67, and display unit 68. The database 67 has an area for storing various data such as instrument data, damage evaluation results, and a Kalman filter described later, and is built, for example, on an auxiliary storage device on an HDD (Hard Disk Drive).

[0037] The signal receiving unit 61 receives time-series data of acceleration a from acceleration meters 41 installed at each measurement point and time-series data of tension from tension meters 42 via network equipment 5d. The signal receiving unit 61 transmits the time-series data of acceleration a, along with identification information of the acceleration meter 41 including its position information, to the displacement calculation unit 62, the response load estimation unit 63, and the database 67. The signal receiving unit 61 also transmits the time-series data of tension, along with identification information of the tension meter 42 including its position information, to the response load estimation unit 63 and the database 67.

[0038] The displacement calculation unit 62 calculates the displacement x at the measurement point of the acceleration measuring instrument 41. The displacement x is calculated by numerical integration using the central difference method, for example, as shown in equation (1). The displacement x is calculated for each measurement point and is expressed in the form of, for example, the displacement x of the nacelle 12 or the displacement x of the floating body 2.

[0039]

number

[0040] Here, Δt represents the sampling period of the acceleration waveform, and i (=1,2,···) represents the time step. Since the displacement x obtained by equation (1) above is subject to drift due to noise and numerical integration errors, a low-pass filter or high-pass filter may be applied to the displacement x to remove these outliers. Also, since the displacement x is a pseudo-value calculated by the displacement calculation unit 62, the displacement x will be referred to as pseudo-displacement x below.

[0041] The response load estimation unit 63 calculates the acceleration x'', velocity x', and displacement x in the surge, sway, heave, roll, pitch, and yaw directions, which are the motion response amounts of the wind power plant 10 occurring at representative points such as the center of gravity of the nacelle 12 and the floating body 2, based on the measured acceleration a, tension, and displacement x calculated by the displacement calculation unit 62, and further calculates the wave force load f acting on the floating body 2. w We estimate this wave force load f. wThis is calculated from the acceleration a and tension input moment by moment at each time step i.

[0042] For example, the response load estimation unit 63 uses acceleration a and displacement x to calculate the acceleration x'' and displacement x of surge, sway, heave, roll, pitch, and yaw motions at representative points of the wind power plant 10, such as the center of gravity of the nacelle 12 and the floating body 2. Furthermore, the response load estimation unit 63 uses these acceleration x'' and displacement x as observed values ​​y(t) and reduces the measurement error included in the observed values ​​y(t) by using a Kalman filter such as a nonlinear Kalman filter, thereby calculating the wave force load f w The Kalman filter estimates the wave force load f, which cannot be directly measured, based on instrument data and equations of motion. w We will make an estimate.

[0043] The response load estimation unit 63 calculates a Kalman gain G(k) obtained from the difference between the pre-estimated state variables calculated based on the equations of motion that model the behavior of the wind power plant 10 and the observed value y(t), as shown below, and calculates a post-estimate using a Kalman filter. In the Kalman filter, the state variables to be estimated include, for example, at least one of the following: displacement, velocity, acceleration, overacceleration, wave force load, time derivative of the wave force load, time derivative of the tidal force load, and a parameter representing the speed of motion at a representative point of the wind power plant 10. In addition, in the Kalman filter, the observed values ​​include, for example, the displacement and acceleration at a representative point of the wind power plant 10.

[0044] In this embodiment, the response load estimation unit 63 calculates a prior estimate using the state equation represented by equation (2) and the observation equation represented by equation (3).

[0045]

number

[0046]

number

[0047] Here, \(x(t)\) represents state variables for state quantities to be estimated such as displacement \(x\), velocity \(x'\), acceleration \(x''\), and wave force load \(f\). \(\theta(t)\) represents information regarding wave force load, etc. to be estimated. \(z\) represents a variable obtained by arranging state variables to be estimated and unknown inputs. \(u(t)\) represents input values of known values such as control inputs. \(f\) and \(h\) represent non - linear functions of \(x(t)\). \(\gamma(t)\) represents system noise generated from various devices constituting the wind power generation system 100, and \(\eta(t)\) represents observation noise. Also, the state equation is formulated by the response quantity load estimation unit 63 using the equation of motion of a spring - mass system that simply models the behavior of the wind power generation plant 10 represented by Equation (4). Further, the prior estimated value is obtained, for example, by substituting each state variable into Equation (3) after the state equation is formulated by the equation of motion.

[0048]

Number

[0049] The right - hand side represents the external force acting on the wind power generation plant 10, and the left - hand side represents the internal force generated in the wind power generation plant 10. \(M\) is the mass (here, the sum of the mass of the floating windmill and the added mass of the fluid is used). \(C\) is the damping (here, in addition to structural damping, the damping due to viscous resistance and the damping of the vibration energy generated by the swaying of the floating body 2, etc., the damping caused by the interaction between the floating body 2 and the fluid is represented as a constant). \(K\) represents the matrix of the restoring force rigidity due to hydrostatic pressure and gravity. \(f\) w (t) is the wave force, \(f\) m (t) is the mooring force, \(f\) c (t) is the resistance due to ocean current (hereinafter, also referred to as the current force load), \(f\) a (t) is the aerodynamic force of the windmill, \(f\) s (t) represents the vector of seismic forces respectively. The seismic force vector \(f\) s ​​(t) is a value that indicates the external force transmitted to the wind power plant 10 via the anchors of the mooring cable 3, and when tension mooring 32 is used, the load acting due to the seismic force vector is larger than when catenary mooring 31 is used. Therefore, depending on the type of mooring cable 3 used for the wind power plant 10, the seismic force vector f s The value of (t) may be adjusted. The values ​​used in equation (4), such as the mass M, damping C, and the matrix K representing the restoring force stiffness due to hydrostatic pressure and gravity, may be stored in the database 67 in advance by the user.

[0050] The response load estimation unit 63 calculates the pre-estimated value z from the physical model of the state variable, as shown in equation (5). ^- (k), the observed value y(k), and the prior estimate of the observed value y ^- By adding a correction term obtained by multiplying the difference in (k) by the Kalman gain G(k), state estimation using a Kalman filter at time step k is performed.

[0051]

number

[0052] Prior estimate z ^- (k) is an estimate of the state variable z at time step k-1, which is one step prior to time step k. ^ (k-1) is calculated using a physical model, and equation (5) is a recurrence relation determined by the relationship between k and k-1. The response load estimation unit 63 uses equation (5) to sequentially estimate the state variables for each state variable at each time step. The time step k may be the same value as the time step i.

[0053] In this embodiment, the Kalman filter used by the response load estimation unit 63 assumes that the estimated values ​​of the state variables follow a normal distribution at each time step. However, equation (5) becomes a nonlinear equation depending on the physical model and state variables used, so even if the initial values ​​of the state variables follow a normal distribution, the state variables may cease to follow a normal distribution as time progresses. Therefore, the response load estimation unit 63 may use an unscented Kalman filter (UKF) that approximates the probability distribution of the state variables as a normal distribution on a collectively averaged basis using a small number of sample points. For example, the response load estimation unit 63 may use the equation of motion for heave motion of a floating wind turbine with one mass and one degree of freedom in the equation of motion shown in equation (4), and use equations (6) and (7), respectively, as more concrete equations for the state equation and observation equation shown in equations (2) and (3).

[0054]

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[0055]

number

[0056] In equation (6), x represents displacement, x' represents velocity, x'' represents acceleration, x''' represents jerk, M represents mass (here again, the sum of the mass of the floating wind turbine and the fluid-added mass is used), C represents the damping coefficient of the floating body, and K represents the restoring force coefficient due to hydrostatic pressure and gravity. - w In equation (4), after dividing both sides by the mass M, f - w The wave forcing obtained by rearranging the terms to the form = represents f - m and f - c In equation (4), after dividing both sides by the mass M, f - m = and f - c The mooring force f is obtained by rearranging the equation to the form =. -m and drag f due to ocean currents - c represents the drag force f due to ocean currents. θ1 and θ2 represent parameters that model the speed of motion of a floating wind turbine, and θ3 and θ4 represent the drag force f due to ocean currents. - c The mooring force f - m This represents a parameter that is modeled as being proportional to the low-frequency components, with γ and η representing the virtual system noise and observed noise, respectively.

[0057] Mooring force f - m Here, the load is considered a quasi-static load that depends only on the displacement x of the floating body. The response load estimation unit 63 estimates the mooring force f - m Using the correspondence data between and displacement x, the mooring force f - m This is calculated. This correspondence data could potentially be stored in database 67 by the user in advance for damage assessment.

[0058] Also, in equation (7), f ^ m (x) is the axial load on the mooring rope 3, and the mooring force f - m Similarly, it is treated as a quasi-static load that depends only on the displacement x of the floating body. The response load estimation unit 63 calculates the axial load f of the mooring rope 3. ^ m Using the data of the correspondence between (x) and displacement x, f ^ m (x) is calculated. This correspondence data can be stored in database 67 in advance by the user when assessing damage.

[0059] f ^ m,obs This shows the axial load of the mooring rope 3 as measured by the tension measuring instrument 42. Therefore, f ^ m (x) ≈ f ^ m,obs To achieve this, we must set the third term on the left-hand side of the observation equation (equation (7)) to y3=0.

[0060] Furthermore, the equation of motion shown in equation (4), the equation of state shown in equation (6), and the observation equation shown in equation (7) may be extended to a spring-mass model that describes the surge, sway, heave, roll, pitch, and yaw motion of the wind power plant 10, as well as the motion of the tower 14 and nacelle 12.

[0061] The wave height estimation unit 64 calculates the wave force load f w Based on (k), the wave height ζ incident on the floating body 2 is calculated. The wave height estimation unit 64 calculates the wave force load f w The transfer function H identified by machine learning regarding the relationship between (k) and wave height ζ may be stored in the database 67 beforehand. Wave force load f acting on floating body 2 w (k) Then the wave height estimation unit 64 calculates the wave force load f as shown in equation (8). w The wave height ζ is calculated by multiplying (k) by the transfer function H. The wave height estimation unit 64 calculates the wave force load f obtained by the response load estimation unit 63. w Based on (k), the wave height ζ at time step k is calculated. The wave height estimation unit 64 may use data fitting methods such as autoregressive-moving average models for machine learning, or it may use AI (Artificial Intelligence) methods such as neural networks. For machine learning, the wave height estimation unit 64 may determine the parameters of the autoregressive-moving average model or the neural network model and identify the transfer function H using the results of numerical simulations using time history data of wave height incident on the floating body 2 of the wind turbine 1 under evaluation, or time history data of wave force loads calculated by tank experiments.

[0062]

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[0063] The time history response calculation unit 65 receives the acceleration x, velocity x'', and displacement x''' of the floating body 2 obtained by the response load estimation unit 63, and the wave height ζ obtained by the wave height estimation unit 64 as input, and analyzes the wave pressure acting on the surface of the floating body 2 and the inertial force due to the oscillation of the floating body 2, and evaluates the stress and strain generated in the floating structure, such as the floating body 2 and the mooring ropes 3. In evaluating the stress and strain generated in the floating structure, the time history response calculation unit 65 uses, for example, FEM (Finite Element Method) analysis to evaluate the stress and strain generated in the floating body 2.

[0064] The damage evaluation unit 66 evaluates the damage to the floating body 2 using the stress or strain generated in the floating body 2, which has been evaluated by the time history response calculation unit 65. The damage evaluation unit 66 may also evaluate the damage to the floating body 2 using both stress and strain. When evaluating the damage, the user may, for example, store in the database 67 data in advance the correspondence between the cumulative damage coefficient calculated from a fatigue diagram representing the relationship between the stress or strain and the degree of damage of the floating body 2 of the wind power plant 10, and the allowable value of the degree of damage. The damage evaluation unit 66 may evaluate the damage by comparing the cumulative damage coefficient corresponding to the stress or strain of the floating body 2, which has been evaluated by the time history response calculation unit 65, with the allowable value. For example, if the cumulative damage coefficient exceeds the allowable value, the damage evaluation unit 66 evaluates that the floating body 2 is damaged, and even if it does not exceed the allowable value, if the value is close to it, it evaluates that the floating body is in a state close to damage and should be monitored. The damage evaluation unit 66 transmits the results of the damage evaluation of the floating body 2 to the database 67 and the display unit 68. The evaluation criteria are just examples; other indicators may be used.

[0065] Furthermore, the damage evaluation unit 66 calculates a cumulative fatigue damage coefficient corresponding to the stress or strain of the tower 14 from fatigue diagrams stored in the database 67 in advance. The damage evaluation unit 66 evaluates the damage to the tower 14 by comparing this cumulative fatigue damage coefficient with an allowable value stored in the database 67 in advance.

[0066] For example, the damage evaluation unit 66 calculates a relative displacement from the displacement x of the nacelle 12 and the displacement x of the floating body 2 calculated by the response load estimation unit 63, and uses this relative displacement to calculate the stress or strain generated in the tower 14. The damage evaluation unit 66 uses the calculated stress or strain to evaluate the damage to the tower 14. The relative displacement can be calculated by subtracting the displacement x of the floating body 2 from the displacement x of the nacelle 12. When evaluating damage, the user may, for example, store in the database 67 data in advance on the correspondence between the cumulative damage coefficient calculated from a fatigue diagram representing the relationship between the stress or strain and the degree of damage of the tower 14 of the wind power plant 10, and the allowable value of the degree of damage. The damage evaluation unit 66 may evaluate the damage by comparing the cumulative damage coefficient corresponding to the stress or strain generated in the tower 14 with the allowable value. The damage evaluation unit 66 transmits the results of the damage evaluation of the tower 14 to the database 67 and the display unit 68.

[0067] The display unit 68 generates a display signal to display the evaluation results on the display device 50. The evaluation results may be displayed in various ways, such as by showing the extent of damage using text data, or they may be displayed visually in an easy-to-understand manner via a user interface, such as showing where the damage occurred in the wind power plant 10. In addition, if damage occurs, the display unit 68 may generate signals other than display signals, such as an audio signal to sound a warning.

[0068] Figure 4 is an example of a flowchart of the wind power generation system 100 in the first embodiment.

[0069] The flowchart in this embodiment describes the flow of how the wind power plant evaluation device 6 evaluates damage to the floating body 2 and tower 14 in the wind power plant 10. Although acceleration a and tension are constantly measured by acceleration measuring instruments 41 and tension measuring instruments 42 set at each measurement point, respectively, for the sake of simplicity, the damage evaluation will be explained using the data at time step i from the time-series data received by the signal receiving unit 61.

[0070] In step S11, the acceleration measuring instrument 41 measures the acceleration at time step i in the wind turbine 1 and the floating body 2. In this step, the acceleration at time step i is measured at each measurement point in the wind turbine 1 and the floating body 2. In step S12, the tension measuring instrument 42 measures the tension in the mooring rope 3 at time step i. In this step, the tension at time step i, for example, the axial load of the mooring rope 3, is measured at each measurement point in the mooring rope 3.

[0071] In step S2, the signal receiving unit 61 receives acceleration data a and tension data via the network device 5d. The signal receiving unit 61 transmits the acceleration data a, along with identification information of the acceleration measuring instrument 41 including its position information, to the displacement calculation unit 62, the response load estimation unit 63, and the database 67. The signal receiving unit 61 also transmits the tension data, along with tension measuring instrument identification information including the position information of the tension measuring instrument 42, to the response load estimation unit 63 and the database 67. In this step, the displacement calculation unit 62 calculates the displacement x (pseudo-displacement x) based on the acceleration a. The displacement calculation unit 62 calculates the displacement x using, for example, equation (1).

[0072] In step S3, the response load estimation unit 63 uses a Kalman filter to calculate the wave force load f from the acceleration a and displacement x obtained in the above step. w The response load estimation unit 63 estimates the wave force load f using, for example, equations (2) to (7). w We estimate this.

[0073] In step S4, the wave height estimation unit 64 calculates the wave force load f acting on the floating body 2. w The wave height ζ incident on the floating body 2 is calculated by multiplying this by the transfer function H. The wave height estimation unit 64 calculates the wave height ζ using, for example, equation (8).

[0074] In step S5, the time history response calculation unit 65 evaluates the stress and strain generated in the floating structure. The time history response calculation unit 65 evaluates the stress and strain at time step i, for example, using FEM analysis.

[0075] In step S6, the damage evaluation unit 66 evaluates the damage to the floating body 2 using the stress or strain generated in the floating structure, which has been evaluated by the time history response calculation unit 65. The damage evaluation unit 66 evaluates the damage by comparing, for example, a cumulative damage coefficient corresponding to the stress or strain of the floating body 2 with an allowable value. The damage evaluation unit 66 also transmits the results of the damage evaluation of the floating body 2 to the database 67 and the display unit 68.

[0076] In step S7, the damage evaluation unit 66 evaluates the damage to the tower 14 based on the relative displacement between the nacelle 12 and the floating body 2. For example, the damage evaluation unit 66 uses the relative displacement between the nacelle 12 and the floating body 2 to calculate the stress or strain generated in the tower 14, and evaluates the damage by comparing the cumulative damage coefficient corresponding to the stress or strain with an allowable value. The damage evaluation unit 66 also transmits the results of the damage evaluation of the tower 14 to the database 67 and the display unit 68.

[0077] In step S8, the display unit 68 generates a display signal from the evaluation results of the floating body 2 and the tower 14, and displays the evaluation results on the display device 50. The user can check whether or not there is any damage to the wind power plant 10 from the evaluation results displayed on the display device 50.

[0078] Figure 5 is a hardware configuration diagram of the wind power plant evaluation device 6 in the first embodiment.

[0079] The wind power plant evaluation device 6 in Figure 5 includes a processor 52 such as a CPU, a main memory 53 such as RAM, an auxiliary storage device 54 such as an HDD, a network interface 55 such as a LAN (Local Area Network) board, a device interface 56 such as memory slots and memory ports, and a bus 57 that connects these devices to each other. The wind power plant evaluation device 6 is, for example, a computer such as a PC, and is equipped with external input devices such as a keyboard and mouse, and a display device such as an LCD monitor.

[0080] In this embodiment, a program for causing a computer to perform information processing on the wind power plant evaluation device 6 is installed in the auxiliary storage device 54. The wind power plant evaluation device 6 loads this program into the main storage device 53 and executes it using the processor 52. This enables the functions of the signal receiving unit 61, displacement calculation unit 62, response load estimation unit 63, wave height estimation unit 64, time history response calculation unit 65, damage evaluation unit 66, database 67, and display unit 68 shown in Figure 3 to be realized within the wind power plant evaluation device 6, making it possible to evaluate the damage to the wind power plant 10 as described in the first embodiment. The data generated by this information processing is temporarily held in the main storage device 53 or stored in the auxiliary storage device 54.

[0081] Furthermore, the database 67 is built on auxiliary storage device 54. The threshold values ​​mentioned above are stored in auxiliary storage device 54. The threshold values ​​are loaded into main memory device 53 when this program is executed.

[0082] Furthermore, the wind power plant evaluation device 6 is connected to network equipment 5d via a network interface 55. The wind power plant evaluation device 6 also controls the network interface 55 via a signal receiving unit 61 to acquire measurement data. The cell evaluation results may also be output to a display device 50 such as an LCD monitor.

[0083] The wind power plant evaluation program for the wind power plant evaluation device 6 can be installed, for example, by attaching an external device 58 containing the program to the device interface 56 and storing the program from the external device 58 to the auxiliary storage device 54. An example of the external device 58 is a computer-readable recording medium or a recording device that incorporates such a recording medium. Examples of recording media include CD-ROM (Compact Disk Read Only Memory), CD-R (Compact Disk Recordable), flexible disk, DVD-ROM (Digital Versatile Disk Read Only Memory), and DVD-R (Digital Versatile Disk Recordable), while an example of a recording device is an HDD. The program can also be installed, for example, by downloading it via the network interface 55.

[0084] According to this embodiment, the wind power plant evaluation device 6 can evaluate damage to the floating body 2 and tower 14 based on the acceleration a and tension measured by the acceleration meter 41 and tension meter 42, taking into account the load on the mooring ropes 3 which changes significantly due to the swaying of the floating body 2. By performing a damage evaluation of the wind power plant 10, the lifespan and damage status of the wind power plant 10 can be estimated.

[0085] Furthermore, according to this embodiment, it is unnecessary to install strain gauges on the tower 14 and floating body 2 of the wind power plant 10 for damage assessment of the wind power plant 10. As a result, the costs of installing and maintaining strain gauges in the wind power generation system 100 can be reduced. Therefore, the maintenance costs of the wind power generation system 100 can be reduced.

[0086] Furthermore, according to this embodiment, the displacement calculation unit 62 calculates the displacement x at the measurement point based on the acceleration a measured by the acceleration measuring instrument 41. This reduces the costs of installing and maintaining displacement measuring instruments in the wind power generation system 100. As a result, the maintenance costs of the wind power generation system 100 can be further reduced.

[0087] (Second Embodiment) Figure 6 shows a detailed configuration of the wind power generation system 100 in the second embodiment.

[0088] In this embodiment, for example, the general configuration of the wind power generation system 100, the hardware configuration of the wind power plant evaluation device 6, some of the functional blocks, and some of the flowcharts, etc., which are mainly the same as in the embodiments described above, will be omitted from the explanation.

[0089] In this embodiment, in addition to the acceleration meter 41 and tension meter 42, a position information meter 43 is installed in the wind power plant 10. The position information meter 43 is installed at one or more measurement points of the wind power plant 10 and is configured to measure the position information of the measurement points. In this embodiment, the position information meter 43 is installed on the rotor 15 and tower 14 of the wind turbine 1, but it may be installed at any location on the wind turbine 1 or floating body 2.

[0090] The position information measuring instrument 43 is, for example, a GPS (Global Positioning System) signal receiving device, and the wind power plant evaluation device 6 calculates displacement x using the change in position information at the measurement point when a wave load acts on the wind power plant 10, in addition to the change in acceleration measured by the accelerometer 41. For example, it is conceivable to measure displacement x based on position information calculated from the difference in time steps at two different times. Alternatively, a GNSS (Global Navigation Satellite System) gyroscope capable of measuring the attitude of the wind power plant 10 may be used as the position information measuring instrument 43. The measurement point by the position information measuring instrument 43 (for example, the rotor 15 or the tower 14) is also called the third measurement point.

[0091] The position information measuring instrument 43 is installed, for example, on the nacelle 12 and the floating body 2. In this embodiment, an example is shown in which the position information measuring instrument 43 is installed on the nacelle 12 and the floating body 2. By using the instrument data measured by the position information measuring instrument 43, the response load estimation unit 631 can capture slow changes in the position of the wind power plant 10 and calculate the displacement x with greater accuracy than if it were using the instrument data measured by the acceleration measuring instrument 41. For example, when using catenary mooring 31, the position of the wind power plant 10 may change slowly due to the influence of wind, waves, or currents. In such cases, calculating the displacement x using the position information measuring instrument 43 is more accurate.

[0092] In this embodiment, the operation of the displacement calculation unit 621 and the response load estimation unit 631 in the wind power plant evaluation device 6 differs, so this will be explained using a flowchart.

[0093] Figure 7 is an example of a flowchart of the wind power generation system 100 in the second embodiment.

[0094] This flowchart describes a flow that differs from the first embodiment. In step S13, the position information measuring instrument 43 measures the position information of the nacelle 12 and the floating body 2 at time step i.

[0095] In step S2, the signal receiving unit 61 receives acceleration data a, tension data, and position information data via the network device 5d. The signal receiving unit 61 transmits the position information data, along with the identification information of the position information measuring instrument 43, to the displacement calculation unit 621 and the database 67. In this step, the displacement calculation unit 621 calculates the displacement x (pseudo-displacement x) based on the position information. The displacement x at time step i is calculated, for example, by taking the difference between the position information at time step i and the position information at time step i-1.

[0096] In step S3, the response load estimation unit 631 calculates the acceleration x'' and displacement x of surge, sway, heave, roll, pitch, and yaw motion at representative points such as the center of gravity of the nacelle 12 and the floating body 2, using the acceleration a and tension, as well as the displacement x calculated in step S2. Furthermore, the response load estimation unit 631 uses the observed values ​​y(t) of acceleration x'' and displacement x to calculate the wave force load f using a Kalman filter. w We estimate this.

[0097] In a floating wind power plant 10, the natural periods of surge, sway, pitch, and roll motion of the wind turbine 1 are longer compared to other types, and steady-state changes occur due to waves and wind. According to this embodiment, the wind power plant evaluation device 6 calculates the displacement x using the position information measuring instrument 43. As a result, the wind power plant evaluation device 6 can capture slow changes in position, unlike the motion captured by the acceleration measuring instrument 41, and the wave force load f acting on the wind turbine 1. w This can improve the accuracy of the estimation.

[0098] (Third embodiment) Figure 8 shows a detailed configuration of the wind power generation system 100 in the third embodiment.

[0099] In this embodiment, for example, the general configuration of the wind power generation system 100, the hardware configuration of the wind power plant evaluation device 6, some of the functional blocks, and some of the flowcharts, etc., which are mainly the same as in the embodiments described above, will be omitted from the explanation.

[0100] In this embodiment, in addition to the acceleration meter 41 and tension meter 42, a wind speed meter 44 is installed in the wind power plant 10. The wind speed meter 44 is installed at one or more measurement points in the wind power plant 10. The wind speed meter 44 is installed, for example, on the rotor 15 of the wind turbine 1 and is configured to measure wind speed. Although not described in this embodiment, as in the embodiment described above, a position information meter 43 may be installed in the wind power plant 10, and the wind power plant evaluation device 6 may calculate displacement x from the position information acquired from the position information meter 43.

[0101] The wind speed measuring instrument 44 is, for example, an anemometer that measures wind speed v. Instead of measuring wind speed v with the wind speed measuring instrument 44, the wind power plant evaluation device 6 may estimate wind speed v using a known extended Kalman filter. The wind power plant evaluation device 6 calculates the thrust force affecting the motion of the floating body 2 from the wind speed v, improving the accuracy of estimating the drag force associated with wave forces and tidal currents during wind turbine operation. The measurement point by the wind speed measuring instrument 44 (e.g., rotor 15) is also called the fourth measurement point.

[0102] The wind speed v is measured, for example, at each time step i. The signal receiving unit 61 receives acceleration data a, tension data, and wind speed v data as time-series data via the network device 5d.

[0103] In this embodiment, the wind power plant evaluation device 6 includes a thrust force calculation unit 623 that calculates the thrust force acting on the rotor of the wind power plant 10, for example, the wind turbine 1. The thrust force calculation unit 623 calculates the thrust force f using, for example, equation (9). a Perform the calculation in (v). In the calculation of thrust force using equation (9), the density of air is ρ and the rotor area is A. r Lotus thrust coefficient C t (λ,β), peripheral speed ratio λ=(ω r R) / v, rotor rotational angular velocity ω r The rotor radius R and blade pitch angle β are used. The thrust force calculation unit 623 uses the air density ρ and rotor area A. r And for the rotor radius R, the values ​​stored in database 671 beforehand will be used. Also, C t Since the value of is determined from the correspondence between wind speed v and blade pitch angle β, the thrust force calculation unit 623 calculates C from the correspondence between wind speed v and blade pitch angle β that has been stored in the database 671 in advance. t This is what we are seeking.

[0104]

number

[0105] As described above, the values ​​other than the wind speed v in equation (9) are those stored in database 671, as stated above. Air density ρ, rotor area A r Furthermore, it is conceivable that the user may pre-store data on the correspondence between rotor radius R, wind speed v, and blade pitch angle β in the database 67 for damage assessment.

[0106] When estimating wind speed v using an extended Kalman filter, for example, the thrust force calculation unit 623 estimates wind speed v using an extended Kalman filter, based on the balance between the rotor torque and generator torque of the wind turbine 1 and a fluctuating wind speed model. The thrust force calculation unit 623 then uses the estimated wind speed v and the values ​​stored in the database 671 to substitute them into equation (9) to obtain the thrust force f a Perform the operation on (v).

[0107] Figure 9 is a flowchart of the wind power generation system 100 in the third embodiment.

[0108] In this embodiment, the operation of the response load estimation unit 632 is mainly different. Due to the thrust force, for example, wind load is applied to the RNA (mainly the nacelle 12) of the wind power plant 10, causing the entire wind power plant 10 to tilt. In this embodiment, in order to take into account the rotational motion of the RNA and the floating body 2 caused by the thrust force, the response load estimation unit 632 uses equation (10), which has an increased number of degrees of freedom, instead of the one-degree-of-freedom equation of motion used in equation (4), as will be described later, to estimate the wave force load f w The following may be estimated. The response load estimation unit 632 estimates the wave force load f based on acceleration a, tension and thrust force. w Calculate.

[0109] In step S14, the wind speed measuring instrument 44 measures the wind speed v at time step i in the rotor 15. When estimating the wind speed v using an extended Kalman filter, for example, the thrust force calculation unit 623 estimates the wind speed v from the balance between the wind turbine rotor torque and the wind turbine generator torque of the wind turbine 1 and from a fluctuating wind speed model.

[0110] In step S15, the thrust force calculation unit 623 calculates the thrust force f acting on the rotor 15 using the measured or estimated wind speed v. a (v) according to Equation (9).

[0111] In step S3, the response quantity load estimation unit 632 calculates the wave force load f using the equation of motion of Equation (10). Equation (10) is a two-particle three-degree-of-freedom equation of motion with the RNA and the floating body 2 regarded as particles and having a total of three degrees of freedom in the horizontal (front-back, left-right) and vertical (up-down) directions. Also, the response quantity load estimation unit 632 estimates the wave force load f using the state equation and the observation equation shown in Equations (6) and (7), etc. w etc. w etc.

[0112]

Equation

[0113] Although Equation (10) is a simplified equation of motion with respect to the degrees of freedom, it may be extended to a two-particle nine-degree-of-freedom model representing the three degrees of freedom of the horizontal and vertical motions of the RNA and the six degrees of freedom (surge, sway, heave, roll, pitch, yaw motions) of the floating body 2.

[0114] x r is the horizontal displacement of the RNA, x f is the surge displacement of the floating body, θ f is the pitch rotation angle of the floating body, m r is the mass of the RNA, m f is the mass of the floating body, I f is the moment of inertia of the RNA, I f is the moment of inertia of the floating body, c r is the damping coefficient of the tower, c f , c θf is the damping coefficient of the floating body, k r is the stiffness of the tower, k f is the restoring force stiffness of the floating body 2, and h represents the height between the centers of gravity of the RNA and the floating body. Also, respectively, f a is the rotor thrust force, f w,x is the wave force in the surge direction, f <C w,θThis represents the load associated with the wave moment in the pitch direction.

[0115] According to this embodiment, the wind power plant evaluation device 6 measures the wave force load f w In estimating this, the accuracy of estimating the drag due to wave forces and tidal currents during wind turbine operation can be improved by considering the thrust force of the rotor 15 that affects the motion of the floating body 2.

[0116] Figure 10 shows a detailed configuration of the wind power generation system 100 in the fourth embodiment.

[0117] In this embodiment, for example, the general configuration of the wind power generation system 100, the hardware configuration of the wind power plant evaluation device 6, some of the functional blocks, and some of the flowcharts, etc., which are mainly the same as in the embodiments described above, will be omitted from the explanation.

[0118] In this embodiment, the wind power plant 10 comprises a wind turbine 1, a floating body 2, and a catenary mooring 31. The floating body 2 is also equipped with a column 21, a weight 25, and a lower hull 24.

[0119] Column 21 is equipped with the wind turbine 1 and generates a vertical restoring force. The lower hull 24 is a semi-submersible floating structure equipped with column 21 and the wind turbine 1. The counterweight 25 generates a restoring force by gravity when the wind turbine 1 and the floating structure 2 tilt due to waves or other factors.

[0120] Furthermore, the weight 25 is suspended by a wire-like support structure 26, which is supported by the lower hull 24. A tension measuring instrument 42 is also installed on the support structure 26. Additionally, a wire-like support structure 16 that stiffens the tower 14 is supported by the lower hull 24, and a tension measuring instrument 42 is also installed on the support structure 16.

[0121] In addition, in the present embodiment, the tension measuring device 42 is configured to be able to measure the load acting on the catenary mooring 31, and is also configured to be able to measure the tension acting on the support structures 16 and 26 when the wave force load acts on the wind power plant 10. The measurement points (for example, the support structures 16 and 26) by the tension measuring device 42 are also referred to as the fifth measurement points. These time-series data are received by the signal receiving unit 61.

[0122] In the wind power plant evaluation device 6 according to the present embodiment, the tension measuring device 42 measures the tension of the support structures 16 and 26, and further estimates the loads of the support structures 26 and 16 by using an unscented Kalman filter with a motion equation that models the rigidity of the wire-like support structures 26 and 16.

[0123] The response quantity load estimation unit 633 calculates the accelerations x'', velocities x', and displacements x in the surge, sway, heave, roll, pitch, and yaw directions, which are the shaking response quantities of the wind power plant 10, and performs the above estimation by using an unscented Kalman filter with a motion equation that models the rigidity of the support structures 26 and 16. Similar to the above-described embodiment, using equations (4), (6), and (7), in addition to the wave force load f w the loads of the support structures 26 and 16 are estimated.

[0124] The time history response calculation unit 651 uses the loads of the support structures 26 and 16 estimated by the response quantity load estimation unit 633 to analyze, for example, the wave pressure and inertial force acting on the column 21 and the lower hull 24 by using a FEM model, and evaluates the stresses of the support structures 26 and 16.

[0125] The damage evaluation unit 661 evaluates the damage of the support structures 26 and 16 by using the estimated loads of the support structures 26 and 16 and the stresses of the support structures 26 and 16 evaluated by the time history response calculation unit 651.

[0126] The damage evaluation unit 661 calculates a cumulative fatigue damage coefficient corresponding to the stresses in the support structures 26 and 16 from fatigue diagrams previously stored in the database 671. The damage evaluation unit 661 evaluates the damage to the support structures 26 and 16 by comparing this cumulative fatigue damage coefficient with an allowable value previously stored in the database 671. The damage evaluation unit 661 transmits the evaluation results of the damage to each structure to the database 67 and the display unit 681.

[0127] Furthermore, the parameters of the equation of motion used by the response load estimation unit 633, the FEM model used by the time history response calculation unit 651, and the fatigue damage evaluation parameters and cumulative fatigue damage count used by the damage evaluation unit 661 are stored in the database 671.

[0128] The display unit 681 generates a display signal to display the evaluation result on the display device 50. The evaluation result may, for example, display the extent of damage using character data, as in the embodiment described above, or it may be displayed visually in an easy-to-understand manner via a user interface, such as where the damage occurred in the wind power plant 10. In addition, if damage occurs, the display unit 68 may generate signals other than the display signal, such as an audio signal to sound a warning.

[0129] In this embodiment, the wind power plant 10 is described as having a configuration that includes both support structures 26 and 16, but it may also have a configuration that includes only one of them, and the tension measuring instrument 42 may be installed on only one of the support structures 26 and 16. Furthermore, if the wind power plant 10 includes multiple support structures 26 and 16, the tension measuring instrument 42 may be installed on all of the support structures 26 and 16, or on some of these support structures.

[0130] Figure 11 is a flowchart of the wind power generation system 100 in the fourth embodiment.

[0131] This flowchart describes a flow that differs from the first embodiment. In this embodiment, the operation of the response load estimation unit 633, the time history response calculation unit 651, and the damage evaluation unit 661 is mainly different. In this embodiment, in order to consider the tension generated in the support structures 26 and 16, in step S12, the tension measuring instrument 42 measures the tension in the support structures 26 and 16 at time step i.

[0132] In step S3, the response load estimation unit 63 uses an unscented Kalman filter to determine the wave force load f from the acceleration a and displacement x obtained in the same steps as in step 2 of Embodiment 1. w The response load estimation unit 63 estimates the wave force load f using, for example, equations (4), (6), and (7). w And estimate the loads on the supporting structures 26 and 16.

[0133] In step S71, the time history response calculation unit 651 analyzes the wave pressure and inertial force acting on the column 21 and lower hull 24 using an FEM model and evaluates the stresses on the support structures 26 and 16. The damage evaluation unit 661 then evaluates the damage to the support structures 26 and 16 by comparing the cumulative fatigue damage coefficient corresponding to these stresses with the allowable value. The damage evaluation unit 66 then transmits the results of the damage evaluation of the tower 14 to the database 67 and the display unit 68.

[0134] According to this embodiment, the wind power plant evaluation device 6 can evaluate damage by considering the loads of the wire-shaped support structures 26 and 16 that affect the loads acting on the floating body 2 and the wind turbine 1. Furthermore, because the wind power plant evaluation device 6 evaluates the damage to each structure by considering the loads of the support structures 26 and 16, the estimation accuracy and evaluation accuracy of each load can be improved.

[0135] Although several embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel wind power plant evaluation device 6 described herein can be implemented in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made to the forms of the wind power plant evaluation device 6 described herein, without departing from the spirit of the invention. The appended claims and equivalents are intended to include such forms and modifications included in the scope and spirit of the invention. [Explanation of symbols]

[0136] 1: Wind turbine, 2: Floating structure, 3: Mooring rope, 5a: Communication network, 5b: Communication network, 5c: Receiver 5d: Network equipment, 6: Wind power plant evaluation equipment, 10: Wind power plant, 11: Blade, 12: Nacelle, 13: Hub, 14: Tower, 15: Rotor, 16: Support structure, 21: Column, 22: Connecting part, 23: Footing, 26: Support structure, 31: Catenary mooring, 32: Tension mooring, 41: Accelerometer, 42: Tension measuring instrument, 43: Position information measuring instrument, 44: Wind speed measuring instrument, 50: Display device, 52: Processor, 53: Main memory, 54: Secondary memory, 55: Network interface, 56: Device interface, 57: Bus, 58: External device, 61: Signal receiving unit, 62: Displacement calculation unit, 63: Response load estimation unit, 64: Wave height estimation unit, 65: Time history response calculation unit, 66: Damage assessment unit, 67: Database, 68: Display unit, 100: Wind power generation system, 200: Land facilities, 622: Displacement calculation unit, 623: Thrust force calculation unit, 632: Response load estimation unit, 633: Response load estimation unit, 651: Time history response calculation unit, 661: Damage assessment unit, 671: Database, 681: Display unit

Claims

1. A wind power plant evaluation device for evaluating damage to a floating wind power plant subjected to wave loads, A signal receiving unit that receives input of acceleration at a first measurement point when the wave load acts on the wind power plant and tension at a second measurement point when the wave load acts on the mooring rope, A displacement calculation unit that uses time-series data of acceleration at the first measurement point to calculate the displacement at the first measurement point when the wave load acts on the wind power plant, A response load estimation unit that estimates the wave force load acting on the floating body of the wind power plant based on the acceleration at the first measurement point, the displacement at the first measurement point, and the tension at the second measurement point, The system includes a damage evaluation unit that evaluates damage to the wind power plant based on at least one of the stresses and strains generated in the wind power plant calculated from the estimation results of the response load estimation unit, Wind power plant evaluation device.

2. The wind power plant evaluation device according to claim 1, wherein the response load estimation unit takes the acceleration at the first measurement point, the tension at the second measurement point, and the displacement at the first measurement point as inputs and estimates the wave force load based on a Kalman filter using equations of motion that model the behavior of the wind power plant.

3. In the aforementioned Kalman filter, The state variables to be estimated include at least one of the following parameters: displacement, velocity, acceleration, jerk, wave force load, time derivative of wave force load, time derivative of tidal force load, and a parameter representing the speed of motion at a representative point including the floating body. The observed values ​​include at least one of the displacement and acceleration at the representative point of the wind power plant. The wind power plant evaluation device according to claim 2.

4. The wind power plant evaluation apparatus according to claim 3, further comprising a wave height estimation unit that estimates the wave height incident on the floating body using the wave load and transfer function.

5. The wind power plant evaluation apparatus according to claim 4, wherein the wave height estimation unit determines the parameters of an autoregressive moving average model or a neural network and identifies the transfer function using the results of a numerical simulation using time history data of wave height acting on the floating body, or time history data of wave force load calculated by a tank experiment.

6. The wind power plant evaluation device according to claim 4, further comprising a time history response calculation unit that takes the acceleration of the floating body, the velocity of the floating body, and the displacement of the floating body, and the wave height incident on the floating body as inputs, and analyzes the stress and strain generated in the wind power plant, specifically the stress and strain caused by at least one of the floating body and the mooring ropes.

7. A wind power plant evaluation device for evaluating damage to a floating wind power plant subjected to wave loads, A signal receiving unit that receives input of acceleration at a first measurement point when the wave load acts on the wind power plant, tension at a second measurement point when the wave load acts on the mooring rope, and position information at a third measurement point when the wave load acts on the wind power plant. A displacement calculation unit calculates the displacement at the third measurement point when the wave load acts on the wind power plant, based on the time-series data of the position information at the third measurement point. A response load estimation unit that estimates the wave force load acting on the floating body of the wind power plant based on the acceleration at the first measurement point, the displacement at the third measurement point, and the tension at the second measurement point, A wind power plant evaluation device comprising: a damage evaluation unit that evaluates damage to the wind power plant based on the stress or strain generated in the wind power plant calculated from the estimation results of the response load estimation unit;

8. The system further includes a thrust force calculation unit for calculating the thrust force acting on the wind power plant, The signal receiving unit further receives input of the wind speed at the fourth measurement point when the wave load acts on the wind power plant. The thrust force calculation unit estimates the thrust force acting on the wind turbine rotor using the wind speed at the fourth measurement point and the values ​​stored in the database. The response load estimation unit estimates the wave force load acting on the floating body based on the acceleration at the first measurement point, the displacement at the first measurement point, the tension at the second measurement point, and the thrust force. The wind power plant evaluation device according to claim 1.

9. The system further includes a thrust force calculation unit for calculating the thrust force acting on the wind power plant, The thrust force calculation unit is, The wind speed is estimated using an extended Kalman filter with the balance between the rotor torque and generator torque of a wind turbine, and a fluctuating wind speed model. Using the wind speed and the values ​​stored in the database, the thrust force acting on the wind turbine rotor is estimated. The response load estimation unit estimates the wave force load acting on the floating body based on the acceleration at the first measurement point, the displacement at the first measurement point, the tension at the second measurement point, and the thrust force. The wind power plant evaluation device according to claim 1.

10. The signal receiving unit further receives input of tension at a fifth measurement point when the wave load acts on the wind power plant, on a wire-shaped support structure installed in the wind power plant. The response load estimation unit estimates the load acting on the wire-like support structure based on the tension at the fifth measurement point. The damage evaluation unit evaluates the damage to the wire-shaped support structure based on the load acting on the wire-shaped support structure. The wind power plant evaluation device according to claim 1.

11. A wind power generation system comprising a floating wind power plant subjected to wave loads, and a wind power plant evaluation device for evaluating damage to the wind power plant, The wind power plant evaluation device is, A signal receiving unit that receives input of acceleration at a first measurement point and tension at a second measurement point when the wave load acts on the wind power plant, A displacement calculation unit calculates the displacement at the first measurement point when the wave load acts on the wind power plant, based on the time-series data of acceleration at the first measurement point. A response load estimation unit that estimates the wave force load acting on the floating body of the wind power plant based on the acceleration at the first measurement point, the displacement at the first measurement point, and the tension at the second measurement point, A damage evaluation unit that evaluates damage to the wind power plant based on at least one of the stresses and strains generated in the wind power plant calculated from the estimation results of the response load estimation unit, is included. Wind power generation system.

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