Aerodynamic elastic analysis method of vertical axis windmill with overspeed restraining mechanism, program, and aerodynamic elastic analysis method system of vertical axis windmill with overspeed restraining mechanism

Abstract

To provide an aerodynamic elastic analysis method using a characteristic evaluation method capable of steadily analyzing a vertical axis windmill with an overspeed restraining inductor as a base, a program, and an aerodynamic elastic analysis system of the vertical axis windmill with the overspeed restraining inductor.SOLUTION: The method has a first rotation torque calculation step, a second rotation torque calculation step, and a windmill entire rotation torque calculation step. In the first rotation torque calculation step, a total rotation torque of each windmill blade 14 calculated using a variation wind speed varied according to azimuth of each windmill blade 14 and a deformed speed obtained from a deformation amount of the windmill blade 14 due to actions of an aerodynamic force, a gravity and a centrifugal force is a first rotation torque. In the second rotation torque calculation step, a total rotation torque of each overspeed restraining portion 20 calculated using a variation wind speed varied according to azimuth of each overspeed restraining portion 20 and a deformation speed obtained from a deformation amount of the overspeed restraining portion 20 due to the actions of the aerodynamic force, the gravity and the centrifugal force is a second rotation torque.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vertical axis wind turbine, and more particularly to an aeroelastic analysis method for a vertical axis wind turbine equipped with an over-speed suppression mechanism, a program for performing this aeroelastic analysis method, and an aeroelastic analysis system for a vertical axis wind turbine equipped with an over-speed suppression mechanism. [Background technology]

[0002] Horizontal axis wind turbines are generally large for commercial reasons, and installation locations are limited to coastlines and mountainous areas exposed to strong winds. On the other hand, small vertical axis wind turbines can generate electricity even in winds with an average speed of about 3.0 m / s, so they can be installed almost anywhere in Japan and are suitable for local production and consumption, where electricity is generated locally, making them a highly promising type of wind turbine. The applicants have already proposed a vertical axis wind turbine with lower wind speeds than horizontal axis wind turbines, which includes a base with a power generating unit, a rotating unit that rotates around an axis vertical to the base, and a plurality of wind turbine blades that are connected to the rotating unit via arms and rotate around the vertical axis, the arms having a movable unit for suppressing over-rotation that can rotate around the arm axis connecting the rotating unit and the wind turbine blades, the movable unit being equipped with an over-rotation suppression inductor that tilts the movable unit around the arm axis due to the action of centrifugal force, aerodynamic force, and gravity that are generated when the wind turbine rotates, and returns the movable unit to its initial state when the wind turbine stops rotating (Patent Document 1). In addition, in Patent Document 2, for vertical axis wind turbines (mainly Darrieus type wind turbines), it is possible to suppress the weight of the blades, and even if the bending moment generated in the blades changes in the blade span direction, the bending stress σ MAX The present invention proposes a vertical axis wind turbine blade, a vertical axis wind turbine, a design device and method for vertical axis wind turbine blades, and a design program for vertical axis wind turbine blades that keep the abovementioned values below a certain set value. The vertical axis wind turbine equipped with an over-rotation suppression inductor disclosed in Patent Document 1 does not require elastic bodies such as springs, is highly durable, has a simple structure, and can suppress the wind turbine rotation speed in strong wind conditions to a level sufficiently lower than the rated rotation speed (maximum rotation speed). However, it is necessary to establish a method for evaluating the characteristics of a vertical axis wind turbine equipped with such an over-rotation suppression inductor. It should be noted that Patent Document 2 focuses on the design of the blades and blade support members, and is only concerned with the design of the wind turbine body, which is one operating system, and does not propose a design method for wind turbines that have parts with different operating systems. Therefore, the present applicants have proposed a characteristic evaluation method that allows steady-state analysis as a technique for optimal design and performance prediction for vertical axis wind turbines equipped with an over-rotation suppression mechanism (Patent Document 3). According to the characteristic evaluation method of Patent Document 3, when the moment of inertia of the wind turbine main body and the moment of inertia of the over-speed suppression part are determined separately using their respective equations of motion, the torque of the wind turbine main body and the torque of the over-speed suppression part are analyzed separately, which makes it extremely easy to perform simulation analysis of the behavior of a vertical axis wind turbine equipped with an over-speed suppression mechanism.This makes it possible to efficiently design a wind turbine based on simulation results or on actual measurements of the wind turbine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-108917 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-308643 [Patent Document 3] Patent Application No. 2023-035441 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in order to guarantee the durability and performance of the wind turbine, it is important to obtain type certification from a certification body. To do this, it is necessary to conduct aeroelastic analysis that couples the aerodynamic and structural analysis of the developed wind turbine, and to perform unsteady analysis / transient response analysis of the wind turbine.

[0005] An object of the present invention is to provide an aeroelastic analysis method and program for a vertical axis wind turbine equipped with an over-speed suppression mechanism, based on a characteristic evaluation method capable of performing steady-state analysis, and an aeroelastic analysis system for a vertical axis wind turbine equipped with an over-speed suppression mechanism. [Means for solving the problem]

[0006] The aeroelastic analysis method for a vertical axis wind turbine equipped with an over-rotation suppression mechanism of the present invention as set forth in claim 1 comprises a wind turbine main body 10 and an over-rotation suppression part 20, said wind turbine main body 10 comprises a base 11 having a power generating part, a rotating part 12 that rotates around a vertical axis Z relative to said base 11, and a plurality of wind turbine blades 14 that are connected to said rotating part 12 via arms 13 and rotate around said vertical axis Z, said over-rotation suppression part 20 is provided on said arms 13 and has an arm axis connecting said rotating part 12 and said wind turbine blades 14 a method for analyzing aeroelasticity of a vertical axis wind turbine equipped with an over-rotation suppression mechanism, the method comprising: a movable part (21) for suppressing over-rotation that is rotatable around an axis of the arm shaft (13a) or around an axis parallel to the arm shaft (13a); and an over-rotation suppression guide (22) provided on the movable part (21) that tilts the movable part (21) around the arm shaft (13a) by the action of centrifugal force, aerodynamic force, and gravity that are generated when the wind turbine blade (14) rotates, and returns the movable part (21) to its initial state when the rotation of the wind turbine blade (14) stops, and an entire wind turbine rotational torque calculation step of calculating a rotational torque of the entire vertical axis wind turbine from the first rotational torque and the second rotational torque, wherein in the first rotational torque calculation step, the first rotational torque is the total rotational torque for each of the wind turbine blades 14 calculated using a fluctuating wind speed that changes according to the azimuth of each of the wind turbine blades 14 and a deformation speed obtained from the amount of deformation of each of the wind turbine blades 14 due to the action of the aerodynamic force, gravity, and centrifugal force, and in the second rotational torque calculation step, the second rotational torque is the total rotational torque for each of the over-speed suppression portions 20 calculated using a fluctuating wind speed that changes according to the azimuth of each of the over-speed suppression portions 20 and a deformation speed obtained from the amount of deformation of each of the over-speed suppression portions 20 due to the action of the aerodynamic force, gravity, and centrifugal force. The present invention as set forth in claim 2 is a method for aeroelastic analysis of a vertical axis wind turbine equipped with an over-rotation suppression mechanism as set forth in claim 1, characterized in that it comprises an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body portion 10 and the over-rotation suppression portion 20, first structural data relating to the structure of the wind turbine main body portion 10, and second structural data relating to the structure of the over-rotation suppression portion 20, and if the first rotational torque calculated in the first rotational torque calculation step does not become a predetermined rotational torque, the first structural data in the input step is changed. The present invention as set forth in claim 3 is a method for aeroelastic analysis of a vertical axis wind turbine equipped with an over-rotation suppression mechanism as set forth in claim 1, characterized in that it comprises an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body portion 10 and the over-rotation suppression portion 20, first structural data relating to the structure of the wind turbine main body portion 10, and second structural data relating to the structure of the over-rotation suppression portion 20, and if the second rotation torque calculated in the second rotation torque calculation step does not become a predetermined rotation torque, the second structural data in the input step is changed. The present invention as set forth in claim 4 is a method for aeroelastic analysis of a vertical axis wind turbine equipped with an over-rotation suppression mechanism as set forth in claim 1, characterized in that it comprises an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body portion 10 and the over-rotation suppression portion 20, first structural data relating to the structure of the wind turbine main body portion 10, and second structural data relating to the structure of the over-rotation suppression portion 20, and if the entire wind turbine rotational torque calculated in the entire wind turbine rotational torque calculation step does not equal a predetermined rotational torque, at least one of the aerodynamic data, the first structural data, and the second structural data in the input step is changed. The program of the present invention as set forth in claim 5 comprises a wind turbine main body 10 and an over-rotation suppression part 20, the wind turbine main body 10 comprising a base 11 having a power generating part, a rotating part 12 that rotates around a vertical axis Z relative to the base 11, and a plurality of wind turbine blades 14 that are connected to the rotating part 12 via arms 13 and rotate around the vertical axis Z, the over-rotation suppression part 20 being provided on the arms 13 and rotating around an arm axis 13a that connects the rotating part 12 and the wind turbine blades 14 or parallel to the arm axis. a movable part (21) for suppressing over-rotation that is rotatable around a certain axis, and an over-rotation suppression inductor (22) that is provided on the movable part (21) and tilts the movable part (21) around the arm axis (13a) by the action of centrifugal force, aerodynamic force, and gravity that are generated when the wind turbine blades (14) rotate, and returns the movable part (21) to its initial state when the rotation of the wind turbine blades (14) stops, the program for performing an aeroelastic analysis method for a vertical axis wind turbine equipped with an over-rotation suppression mechanism, the program including causing a computer to generate a first rotational torque around the rotating part of the wind turbine main body (10), a first rotational torque calculation step of calculating a first rotational torque around the rotating part of the over-speed suppression portion 20, a second rotational torque calculation step of calculating a second rotational torque around the rotating part of the over-speed suppression portion 20, and an entire wind turbine rotational torque calculation step of calculating an entire wind turbine rotational torque of the vertical axis wind turbine from the first rotational torque and the second rotational torque, wherein in the first rotational torque calculation step, the first rotational torque is the total rotational torque for each of the wind turbine blades 14 calculated using the fluctuating wind speed that changes depending on the azimuth of each of the wind turbine blades 14 and the deformation speed obtained from the amount of deformation of the wind turbine blades 14 due to the action of the aerodynamic force, gravity, and centrifugal force, and in the second rotational torque calculation step, the second rotational torque is the total rotational torque for each of the over-speed suppression portions 20 calculated using the fluctuating wind speed that changes depending on the azimuth of each of the over-speed suppression portions 20 and the deformation speed obtained from the amount of deformation of the over-speed suppression portion 20 due to the action of the aerodynamic force, gravity, and centrifugal force. The present invention as set forth in claim 6 is characterized in that, in the program for the aeroelastic analysis method for a vertical axis wind turbine equipped with an over-rotation suppression mechanism as set forth in claim 5, the computer is made to execute an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body 10 and the over-rotation suppression portion 20, first structure data relating to the structure of the wind turbine main body 10, and second structure data relating to the structure of the over-rotation suppression portion 20, and is made to execute the first rotational torque calculation step and the second rotational torque calculation step using the aerodynamic data, the first structure data, and the second structure data received in the input step. The aeroelastic analysis system for a vertical axis wind turbine equipped with an over-rotation suppression mechanism of the present invention as set forth in claim 7 comprises a wind turbine main body 10 and an over-rotation suppression part 20, wherein the wind turbine main body 10 comprises a base 11 having a power generating part, a rotating part 12 that rotates around a vertical axis Z relative to the base 11, and a plurality of wind turbine blades 14 that are connected to the rotating part 12 via arms 13 and rotate around the vertical axis Z, and the over-rotation suppression part 20 is provided on the arms 13 and connects the rotating part 12 and the wind turbine blades 14. and an over-rotation suppression guide 22 provided on the movable part 21, which tilts the movable part 21 around the arm axis 13a by the action of centrifugal force, aerodynamic force, and gravity generated when the wind turbine blades 14 rotate, and returns the movable part 21 to its initial state when the wind turbine blades 14 stop rotating. the first rotation torque calculation means calculates the total rotation torque for each of the wind turbine blades 14 calculated using a fluctuating wind speed that changes according to the azimuth of each of the wind turbine blades 14 and a deformation speed obtained from the amount of deformation of each of the wind turbine blades 14 due to the action of the aerodynamic force, gravity, and centrifugal force, and the second rotation torque calculation means calculates the total rotation torque for each of the over-speed suppression portions 20 calculated using a fluctuating wind speed that changes according to the azimuth of each of the over-speed suppression portions 20 and a deformation speed obtained from the amount of deformation of each of the over-speed suppression portions 20 due to the action of the aerodynamic force, gravity, and centrifugal force, and the second rotation torque calculation means calculates the total rotation torque for each of the over-speed suppression portions 20 calculated using a fluctuating wind speed that changes according to the azimuth of each of the over-speed suppression portions 20 and a deformation speed obtained from the amount of deformation of each of the over-speed suppression portions 20 due to the action of the aerodynamic force, gravity, and centrifugal force, and the second rotation torque [Effects of the Invention]

[0007] According to the present invention, the torque of the wind turbine main body and the torque of the over-rotation suppression part are separated, and the first rotational torque and the second rotational torque are calculated using the fluctuating wind speed that changes according to the azimuth of the wind turbine blade and the deformation speed obtained from the deformation amount of the wind turbine blade, so that it is possible to perform aeroelastic analysis that couples aerodynamic forces and structural analysis. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing the overall configuration of a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to an embodiment of the present invention; [Figure 2] A perspective view of the main parts of the vertical axis wind turbine [Figure 3] A plan view of a vertical axis wind turbine showing the state in which input wind acts on the vertical axis wind turbine. [Figure 4] Flowchart showing the aeroelastic analysis method for the vertical axis wind turbine [Figure 5] Diagram of aerodynamic data preparation steps [Figure 6] Illustration of the first structural data input step [Figure 7] An explanation of the steps for setting calculation conditions for the wind turbine body [Figure 8] Formula used in the first rotational torque calculation step [Figure 9] Wind turbine rotor equations of motion [Figure 10] 1. First rotational torque calculation step [Figure 11] Explanatory diagram of overspeed suppression part [Figure 12] A diagram showing calculation of the second rotational torque DETAILED DESCRIPTION OF THE INVENTION

[0009] The aeroelastic analysis method for a vertical axis wind turbine equipped with an over-speed suppression mechanism according to the first embodiment of the present invention comprises a first rotational torque calculation step of calculating a first rotational torque around a rotating part of the wind turbine main body, a second rotational torque calculation step of calculating a second rotational torque around a rotating part of the over-speed suppression part, and an entire wind turbine rotational torque calculation step of calculating the rotational torque of the entire vertical axis wind turbine from the first rotational torque and the second rotational torque, wherein in the first rotational torque calculation step, the first rotational torque is the total rotational torque for each wind turbine blade calculated using the fluctuating wind speed which changes according to the azimuth of each wind turbine blade and the deformation speed obtained from the amount of deformation of the wind turbine blade due to the action of aerodynamic force, gravity, and centrifugal force, and in the second rotational torque calculation step, the second rotational torque is the total rotational torque for each over-speed suppression part calculated using the fluctuating wind speed which changes according to the azimuth of each over-speed suppression part and the deformation speed obtained from the amount of deformation of the over-speed suppression part due to the action of aerodynamic force, gravity, and centrifugal force. According to this embodiment, the torque of the wind turbine main body and the torque of the over-rotation suppression part are separated, and the first rotational torque and the second rotational torque are calculated using the fluctuating wind speed that changes according to the azimuth of the wind turbine blade and the deformation speed obtained from the deformation amount of the wind turbine blade, so that it is possible to perform aeroelastic analysis that couples aerodynamic forces and structural analysis.

[0010] A second embodiment of the present invention is an aeroelastic analysis method for a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to the first embodiment, which includes an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body and the over-rotation suppression part, first structural data relating to the structure of the wind turbine main body, and second structural data relating to the structure of the over-rotation suppression part, and if the first rotational torque calculated in the first rotational torque calculation step does not become a predetermined rotational torque, the first structural data in the input step is changed. According to this embodiment, it is easy to carry out an optimum design of the wind turbine main body.

[0011] A third embodiment of the present invention is an aeroelastic analysis method for a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to the first embodiment, which includes an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body and the over-rotation suppression part, first structural data relating to the structure of the wind turbine main body, and second structural data relating to the structure of the over-rotation suppression part, and if the second rotational torque calculated in the second rotational torque calculation step does not become a predetermined rotational torque, the second structural data in the input step is changed. According to this embodiment, it is easy to carry out an optimum design of the over-speed suppression portion.

[0012] A fourth embodiment of the present invention is a method for aeroelastic analysis of a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to the first embodiment, which includes an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body and the over-rotation suppression part, first structural data relating to the structure of the wind turbine main body, and second structural data relating to the structure of the over-rotation suppression part, and if the entire wind turbine rotational torque calculated in the entire wind turbine rotational torque calculation step does not equal a predetermined rotational torque, at least one of the aerodynamic data, the first structural data, and the second structural data in the input step is changed. According to this embodiment, it is easy to carry out optimal design of the wind turbine main body and the over-rotation suppression part.

[0013] A program for carrying out an aeroelastic analysis method for a vertical axis wind turbine equipped with an over-speed suppression mechanism according to the fifth embodiment of the present invention causes a computer to execute a first rotational torque calculation step of calculating a first rotational torque around a rotating part of the wind turbine main body, a second rotational torque calculation step of calculating a second rotational torque around a rotating part of the over-speed suppression part, and an entire wind turbine rotational torque calculation step of calculating an entire wind turbine rotational torque of the vertical axis wind turbine from the first rotational torque and the second rotational torque, wherein in the first rotational torque calculation step, the first rotational torque is the total rotational torque for each wind turbine blade calculated using the fluctuating wind speed that changes depending on the azimuth of each wind turbine blade and the deformation speed obtained from the amount of deformation of the wind turbine blade due to the action of aerodynamic force, gravity, and centrifugal force, and in the second rotational torque calculation step, the second rotational torque is the total rotational torque for each over-speed suppression part calculated using the fluctuating wind speed that changes depending on the azimuth of each over-speed suppression part and the deformation speed obtained from the amount of deformation of the over-speed suppression part due to the action of aerodynamic force, gravity, and centrifugal force. According to this embodiment, the torque of the wind turbine main body and the torque of the over-rotation suppression part are separated, and the first rotational torque and the second rotational torque are calculated using the fluctuating wind speed that changes according to the azimuth of the wind turbine blade and the deformation speed obtained from the deformation amount of the wind turbine blade, so that it is possible to perform aeroelastic analysis that couples aerodynamic forces and structural analysis.

[0014] A sixth embodiment of the present invention is a program for carrying out the aeroelastic analysis method for a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to the fifth embodiment, which causes a computer to execute an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body and the over-rotation suppression part, first structure data relating to the structure of the wind turbine main body, and second structure data relating to the structure of the over-rotation suppression part, and causes the computer to execute a first rotational torque calculation step and a second rotational torque calculation step using the aerodynamic data, first structure data, and second structure data received in the input step. According to this embodiment, it is easy to carry out an optimum design of the wind turbine main body.

[0015] An aeroelastic analysis system for a vertical axis wind turbine equipped with an over-speed suppression mechanism according to a seventh embodiment of the present invention comprises first rotational torque calculation means for calculating a first rotational torque around a rotating part of the wind turbine main body, second rotational torque calculation means for calculating a second rotational torque around the rotating part of the over-speed suppression part, and entire wind turbine rotational torque calculation means for calculating the rotational torque of the entire vertical axis wind turbine from the first rotational torque and the second rotational torque, wherein the first rotational torque calculation means calculates the total rotational torque for each wind turbine blade using the fluctuating wind speed which changes according to the azimuth of each wind turbine blade and the deformation speed obtained from the amount of deformation of the wind turbine blade due to the action of aerodynamic force, gravity, and centrifugal force, and the second rotational torque calculation means calculates the total rotational torque for each over-speed suppression part using the fluctuating wind speed which changes according to the azimuth of each over-speed suppression part and the deformation speed obtained from the amount of deformation of the over-speed suppression part ... According to this embodiment, the torque of the wind turbine main body and the torque of the over-rotation suppression part are separated, and the first rotational torque and the second rotational torque are calculated using the fluctuating wind speed that changes according to the azimuth of the wind turbine blade and the deformation speed obtained from the deformation amount of the wind turbine blade, so that it is possible to perform aeroelastic analysis that couples aerodynamic forces and structural analysis. [Example]

[0016] A method for analyzing the aeroelasticity of a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to one embodiment of the present invention will now be described. FIG. 1 is a diagram showing the overall configuration of a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to this embodiment, and FIG. 2 is a perspective view of the main part of the same vertical axis wind turbine. The vertical axis wind turbine equipped with the over-rotation suppression mechanism according to this embodiment comprises a wind turbine main body 10 and an over-rotation suppression part 20. The wind turbine main body 10 comprises a base 11 having a power generating unit (not shown), a rotating unit 12 that rotates around a vertical axis Z relative to the base 11, and a plurality of wind turbine blades 14 that are connected to the rotating unit 12 via arms 13 and rotate around the vertical axis Z. In this embodiment, there are three wind turbine blades 14. Base 11 is the foundation of the vertical axis wind turbine. Base 11 has legs 11a formed at a predetermined height and a housing section 11b that houses the power generation section. Wind turbine blades 14 are positioned at a predetermined height above the installation surface by legs 11a. The wind turbine blade 14 has a pair of oblique blades 14b extending from the rotating part 12 so that the distance between them increases with increasing distance from the vertical axis Z, and a main blade 14a extending in a direction parallel to the vertical axis Z. In a side view, the wind turbine blade 14 is formed in a roughly triangular shape that is symmetrical with respect to the horizontal axis X. Note that the term "roughly triangular shape" as used here means that the overall shape of the wind turbine blade 14 is close to a triangle, and includes a triangle with curved corners or one of the three sides curved. The wind turbine blade 14 is formed with a streamlined blade cross section with a curved leading edge and a pointed trailing edge.

[0017] The over-rotation suppression portion 20 includes a movable part 21 for suppressing over-rotation and an over-rotation suppression inductor 22 . The movable part 21 is provided on a part of the arm 13. The movable part 21 is rotatable around an arm shaft 13a that connects the rotating part 12 and the wind turbine blade 14. The over-rotation suppression inductor 22 is provided on the movable part 21. The over-rotation suppression inductor 22 tilts the movable part 21 around the arm axis 13a by the action of centrifugal force, aerodynamic force, and gravity that are generated when the wind turbine blade 14 rotates, and returns the movable part 21 to its initial state when the wind turbine blade 14 stops rotating. In this embodiment, the movable part 21 and the over-rotation suppression guide 22 are formed with a blade cross section having the same shape as the wind turbine blade 14, but may be formed with a blade cross section having a different shape from the wind turbine blade 14.

[0018] FIG. 2(a) is a perspective view of the main part of the vertical axis wind turbine when over-speed suppression is not performed, and FIG. 2(b) is a perspective view of the main part of the vertical axis wind turbine when over-speed suppression is performed. As the wind speed increases and the wind turbine blades 14 reach a high rotation speed state, the rotational direction component F1 of the centrifugal force acting on the over-rotation suppression inductor 22 increases, and as the head-up moment due to the rotational direction component F1 of the centrifugal force acting on the over-rotation suppression inductor 22 increases, the inclination angle θ2 increases. As the tilt angle θ2 increases, the projected area of the movable part 21 as seen from the direction of rotation of the wind turbine increases, and a large aerodynamic braking force F2 acts on the movable part 21, suppressing over-rotation of the wind turbine. In strong wind conditions, a large braking force is generated even at low rotation speeds. As a result, in strong wind conditions, the rotation speed of the wind turbine blades 14 is suppressed to a low speed. In this embodiment, the movable part 21 is provided on the arm shaft 13a that connects the rotating part 12 and the wind turbine blades 14, but it may also be provided suspended from the arm shaft 13a. When the movable part 21 is suspended from the arm shaft 13a in this way, the movable part 21 can rotate around an axis parallel to the axis of the arm shaft 13a.

[0019] FIG. 3 is a plan view of a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to this embodiment, showing a state in which an input wind acts on the vertical axis wind turbine. R shown in FIG. 3 is the distance from the rotor rotation axis (vertical axis Z) to the main wing 14a. In aeroelastic analysis, the input wind speed V(t,X,Y,Z) is fluctuating wind data that includes turbulence and varies in both time t and space (X,Y,Z). In the steady-state analysis, the average value of the first rotational torque Q1 generated by one wind turbine blade 14 is calculated, and this is multiplied by the number of blades M (3 in this embodiment) to obtain the first rotational torque Q 10 Calculate. In contrast, in unsteady analysis, it is assumed that each wind turbine blade 14 receives a different input wind speed V(t,X,Y,Z) at the same timing, and calculations must be performed separately for each wind turbine blade 14. Similarly, for the over-speed suppression portion 20, in the unsteady analysis, it is assumed that each over-speed suppression portion 20 receives a different input wind speed V(t, X, Y, Z) at the same timing, and calculations must be performed separately for each over-speed suppression portion 20.

[0020] FIG. 4 is a flowchart showing the aeroelastic analysis method for a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to this embodiment. The aeroelastic analysis method for a vertical axis wind turbine equipped with an over-speed suppression mechanism according to this embodiment comprises a first rotational torque calculation step 30 for calculating a first rotational torque around the rotating part of the wind turbine main body 10, a second rotational torque calculation step 40 for calculating a second rotational torque around the rotating part of the over-speed suppression part 20, and an entire wind turbine rotational torque calculation step 50 for calculating the entire wind turbine rotational torque of the vertical axis wind turbine from the first rotational torque and the second rotational torque. The first rotational torque calculation step 30 prepares aerodynamic data relating to the blade shape of the wind turbine main body portion 10 (S31), inputs first structural data relating to the structure of the wind turbine main body portion 10 (S32), and sets calculation conditions for the wind turbine main body portion 10 (S33), thereby calculating the first rotational torque around the rotating part of the wind turbine main body portion 10.

[0021] Here, in the unsteady analysis, it is necessary to calculate the rotational torque for each wind turbine blade 14. For a unit length (blade element length) dl of one wind turbine blade 14, this blade element length dl is at a certain minute azimuth Ψ (azimuth angle). For example, let three wind turbine blades 14 be wind turbine blades B1, B2, and B3, and wind turbine blade B1 is at the azimuth Ψ. B1 , the wind turbine blade B2 has an azimuth Ψ B2 , the wind turbine blade B3 has an azimuth Ψ B3 If it is in , the azimuth Ψ B1 , azimuth Ψ B2 , azimuth Ψ B3 The relationship between these is shown in Figure 4(b). In the first rotational torque calculation step 30, for each wind turbine blade 14 (B1, B2, B3), the input wind speed V(t, X, Y, Z) of each wind turbine blade 14 is used to calculate the first rotational torque around the rotating part of the wind turbine main body 10. The input wind speed V(t, X, Y, Z) of each wind turbine blade 14 is a fluctuating wind speed that changes depending on the azimuth Ψ of each wind turbine blade 14. First rotation torque Q 10 is the total rotational torque for the wind turbine blades 14 (B1, B2, B3).

[0022] In second rotational torque calculation step 40, second structure data relating to the structure of over-speed suppression portion 20 is input (S41), and second rotational torque around the rotating portion of over-speed suppression portion 20 is calculated. In this embodiment, since movable portion 21 and over-speed suppression guide 22 are formed with a blade cross section having the same shape as wind turbine blade 14, the aerodynamic data in aerodynamic data preparation step 31 can be used in second rotational torque calculation step 40.

[0023] The over-rotation suppression portions 20 corresponding to the wind turbine blades 14 (B1, B2, B3) are referred to as over-rotation suppression portions B1, B2, B3. In the unsteady analysis, the input wind speed V(t, X, Y, Z), which is a fluctuating wind speed, is also used for each of the over-rotation suppression parts 20 (B1, B2, B3). Second rotation torque Q 20 is the total rotational torque for the overspeed suppression portion 20 (B1, B2, B3).

[0024] Azimuth Ψ B1 , azimuth Ψ B2 , azimuth Ψ B3 The fluctuating wind speeds corresponding to the above are prepared in advance in the input wind database 50 as input wind data. The structural analysis system 60 calculates the amount of deformation of the structure due to the aerodynamic forces, gravity, and centrifugal forces acting on the wind turbine blades 14 (B1, B2, B3) and the over-rotation suppression portion 20 (B1, B2, B3). More specifically, the structural analysis system 60 inputs the aerodynamic forces acting on each blade element (unit length) of the wind turbine blades 14 and the over-rotation suppression portion 20 at the same timing, and outputs the amount of deformation of each blade element caused by these aerodynamic forces, gravity, and centrifugal forces. In the first rotational torque calculation step 30, the azimuth Ψ of each wind turbine blade 14 (B1, B2, B3) is calculated. B1 , Ψ B2 , Ψ B3 The total rotational torque for each wind turbine blade 14 (B1, B2, B3) calculated using the fluctuating wind speed that changes depending on the wind speed and the deformation speed obtained from the deformation amount of the wind turbine blade 14 (B1, B2, B3) from the structural analysis system 60 is defined as the first rotational torque. In the second rotation torque calculation step 40, the azimuth Ψ of each of the overspeed suppression portions 20 (B1, B2, B3) is calculated. B1 , Ψ B2 , Ψ B3 The total rotational torque for each of the over-rotation suppression portions 20 (B1, B2, B3) calculated using the fluctuating wind speed that changes depending on the wind speed and the deformation speed obtained from the deformation amount of the over-rotation suppression portion 20 (B1, B2, B3) from the structural analysis system 60 is defined as the second rotational torque.

[0025] If the first rotational torque calculated in the first rotational torque calculation step 30 does not become the predetermined rotational torque, the structure data in the first structure data input step 32 is changed. If the second rotational torque calculated in the second rotational torque calculation step 40 does not become the predetermined rotational torque, the structure data in the second structure data input step 41 is changed.

[0026] The computer executes a first rotational torque calculation step 30, a second rotational torque calculation step 40, and an entire wind turbine rotational torque calculation step 50. The computer also receives input of aerodynamic data relating to the blade shapes of the wind turbine main body portion 10 and the over-rotation suppression portion 20, first structural data relating to the structure of the wind turbine main body portion 10, and second structural data relating to the structure of the over-rotation suppression portion 20, and executes a first rotational torque calculation step 30 and a second rotational torque calculation step 40 using the received aerodynamic data, first structural data, and second structural data. The program according to this embodiment causes the computer to execute a first rotational torque calculation step 30 for calculating a first rotational torque around the rotating part of the wind turbine main body 10, a second rotational torque calculation step 40 for calculating a second rotational torque around the rotating part of the over-speed suppression part 20, and an entire wind turbine rotational torque calculation step 50 for calculating the entire wind turbine rotational torque of the vertical axis wind turbine from the first rotational torque and the second rotational torque. Furthermore, the program according to this embodiment causes the computer to execute an input step of receiving input of aerodynamic data relating to the blade shapes of the wind turbine main body portion 10 and the over-rotation suppression portion 20, first structural data relating to the structure of the wind turbine main body portion 10, and second structural data relating to the structure of the over-rotation suppression portion 20, and causes the computer to execute a first rotational torque calculation step 30 and a second rotational torque calculation step 40 using the aerodynamic data, first structural data, and second structural data received in the input step.

[0027] In addition, if the computer determines that the first rotational torque calculated in the first rotational torque calculation step 30 does not become the preset rotational torque, it can also prompt the user to change the first structural data in the input step. In addition, if the computer determines that the second rotational torque calculated in the second rotational torque calculation step 40 does not become the preset rotational torque, it can also prompt the user to change the second structure data in the input step. Furthermore, if the computer determines that the overall wind turbine rotational torque calculated in the overall wind turbine rotational torque calculation step 50 does not match the preset rotational torque, it can also prompt the user to change at least one of the aerodynamic data, the first structural data, and the second structural data in the input step.

[0028] Furthermore, the program according to this embodiment causes the computer to determine whether the first rotational torque calculated in the first rotational torque calculation step 30 satisfies a preset set rotational torque, and if the computer determines that the calculated first rotational torque does not match the preset set rotational torque, causes the computer to prompt the computer to change the first structural data in the input step. Furthermore, the program according to this embodiment causes the computer to determine whether the second rotational torque calculated in the second rotational torque calculation step 40 satisfies a preset set rotational torque, and if the computer determines that the calculated second rotational torque does not match the preset set rotational torque, causes the computer to prompt the computer to change the second structure data in the input step. The program according to this embodiment also causes the computer to determine whether the entire wind turbine rotational torque calculated in the entire wind turbine rotational torque calculation step 50 satisfies a preset set rotational torque, and if the computer determines that the calculated entire wind turbine rotational torque does not match the preset set rotational torque, causes the computer to prompt the computer to change at least one of the aerodynamic data, the first structural data and the second structural data in the input step. Such a program can be used by being recorded on a computer-readable recording medium, or by being recorded on a computer or downloaded from a cloud server.

[0029] The aeroelastic analysis system for a vertical axis wind turbine equipped with an over-speed suppression mechanism according to this embodiment comprises first rotational torque calculation means for calculating a first rotational torque around the rotating part of the wind turbine main body 10, second rotational torque calculation means for calculating a second rotational torque around the rotating part of the over-speed suppression part 20, and entire wind turbine rotational torque calculation means for calculating the entire wind turbine rotational torque of the vertical axis wind turbine from the first rotational torque and the second rotational torque.

[0030] FIG. 5 is an explanatory diagram of the aerodynamic data preparation step. In the aerodynamic data preparation step 31, the lift coefficient C for each Reynolds number Re at an arbitrary angle of attack α (−180 degrees to +180 degrees) of the wind turbine blade 14 is calculated. L , drag coefficient C D , moment coefficient C M Prepare the following. As for the aerodynamic data of the wind turbine blade 14, publicly available data such as NACA0018 or data obtained by calculation can be used.

[0031] 6A and 6B are explanatory diagrams of the first structural data input step for the wind turbine main body, where Fig. 6A shows the cross-sectional shape of the wind turbine main body 10, and Fig. 6B shows the entire wind turbine main body. In step 32 of inputting structural data for the wind turbine main body, the chord length c of the wind turbine blade 14, the diameter φd of the wind turbine blade 14 rotating around the vertical axis Z, and the height h which is the span of the wind turbine blade 14 are input as design data.

[0032] 7 is an explanatory diagram of the calculation condition setting step for the wind turbine main body, where Fig. 7(a) shows the state in which the wind turbine blades 14 of the wind turbine main body 10 are divided into unit lengths (blade element lengths) dl in the longitudinal direction (blade element analysis), and Fig. 7(b) is a diagram schematically showing the relationship between the input wind speed V0 and the wind turbine blades 14 at each blade element dl. In the example of step 33 for setting calculation conditions for the wind turbine main body, there are three wind turbine blades 14. For a unit length (blade element length) dl of one wind turbine blade 14 (B1), the drag D and lift L are calculated when this blade element length dl is within a certain small range of azimuth Ψ (azimuth angle) (set as ΔΨ = 1 degree), and these are then summed (integrated) over the height direction (span direction) of the wind turbine blade 14 to determine the first rotational torque Q1 generated by one wind turbine blade 14. At the same time, the first rotational torques generated by each wind turbine blade are also calculated for wind turbine blade B2 and wind turbine blade B3, and these are integrated to determine the first rotational torque Q 10 The relationship between azimuth Ψ (azimuth angle), drag D and lift L will be explained in Figure 10 and the corresponding section. In step 33 of setting calculation conditions, if the wind speed is V0, the rotation speed is N, and the tip speed ratio is λ, then λ=Rω1 / V0 N=30ω1 / π where R is the distance from the vertical axis Z to the blade element of the wind turbine blade 14 (radius of rotation), and ω1 is the angular velocity of the blade element of the wind turbine blade 14.

[0033] FIG. 8 shows the formula used in the first rotational torque calculation step 30. In the first rotational torque calculation step 30, the rotational torque is calculated for each wind turbine blade 14 (B1, B2, B3), and the total rotational torque calculated for the wind turbine blades 14 (B1, B2, B3) is defined as the first rotational torque, but in the following explanation, the rotational torque calculated for one wind turbine blade 14 will be described as the first rotational torque.

[0034] The torque around the vertical axis Z due to the main wing 14a is Q 1a (Ψ), the torque around the vertical axis Z due to the inclined blade 14b is Q 1b (Ψ), the torque around the vertical axis Z due to the arm is Q 1c (Ψ), the first rotational torque Q1(Ψ) for one wind turbine blade 14 is expressed by the following equation: Q1(Ψ)=Q 1a (Ψ)+Q 1b (Ψ)+Q 1c (Ψ)

[0035] Torque around the vertical axis Z due to the main wing 14a: Q 1a (Ψ) Within the blade cross section of the j-th blade element of the main wing 14a, the force acting in the chord direction is defined as dF_cd(j), the force perpendicular to that is defined as dF_nd(j), and the lift acting on this blade element cross section is defined as dL, the drag as dD, and the angle of attack as α. Then, the forces dF_cd(j) and dF_nd(j) within the blade element cross section are expressed by equations (1) and (2), respectively. Note that the force acting in the chord direction dF_cd(j), the force perpendicular to that direction dF_nd(j), the lift force dL and drag dD acting on this blade element cross section, the angle of attack α, and the azimuth Ψ are parameters that change over time.

[0036] If the component of the aerodynamic force acting within the blade cross section of the j-th blade element of the main wing 14a in the main flow direction is defined as dF1(j) and the horizontal component perpendicular to the main flow is defined as dF2(j), then when the blade setting angle (pitch angle) is set to 0°, dF1(j) and dF2(j) are expressed as functions of azimuth Ψ by equations (3) and (4), respectively. If the force acting on the j-th blade element of the main wing 14a in the tangential direction of the orbital circle is defined as dFY(j), it can be expressed by equation (5), where the rotation direction is positive. Substituting equations (3) and (4) into equation (5) and rearranging it, we can see that the tangential force dFY(j) is the same as the chordwise force dF_cd(j) (equation (6)). (The blade setting angle is set to 0°.)

[0037] If the distance from the vertical axis Z to the j-th blade element of the main wing 14a is R1(t, j), the rotational torque dQ generated by the j-th blade element of the main wing 14a around the vertical axis Z is 1a (j) is expressed by equation (7). Note that in aeroelastic analysis, the distance R1(t,j) is not constant but changes with time. Alternatively, using equation (1) yields equation (8).

[0038] By adding up the rotational torques given by equation (8) for all blade elements in the longitudinal direction of the main wing 14a, the torque Q1(Ψ) around the vertical axis Z of the main wing 14a at the azimuth Ψ is calculated as shown in equation (9).

[0039] Torque around the vertical axis Z of the oblique wing 14b: Q 1b (Ψ) Within the blade cross section of the jth blade element of the oblique wing 14b, the force acting in the chord direction is defined as dF_cd(j) and the force perpendicular to this is defined as dF_nd(j). If the lift acting on this blade cross section is defined as dL, the drag as dD, and the angle of attack as α, the forces dF_cd(j) and dF_nd(j) within the blade cross section are expressed by equations (10) and (11), respectively.

[0040] The tilt angle of the oblique blades 14b from the vertical direction is defined as γ(t). In the case of a butterfly wind turbine, the tilt angle of the oblique blades 14b in the upper half is constant regardless of the blade element, and if this is defined as a positive value, the tilt angle of the lower half is -γ(t) because the rotor is symmetrical up and down. However, the cosine of the tilt angle, cosγ(t), is a constant positive constant regardless of whether the tilt angle is positive or negative. In this case, if the component of the aerodynamic force acting within the blade cross section of the j-th blade element of the oblique wing 14b in the main flow direction is defined as dF1(j) and the horizontal component perpendicular to the main flow is defined as dF2(j), when the blade setting angle (pitch angle) is set to 0°, dF1(j) and dF2(j) are expressed as functions of azimuth Ψ by equations (12) and (13), respectively. If the force acting on the j-th blade element of the oblique blade 14b in the tangential direction of the orbital circle is defined as dFY(j), it can be expressed by equation (14), where the rotation direction is positive.

[0041] Substituting equations (12) and (13) into equation (14) and rearranging it, we can see that the tangential force dFY(j) is the same as the chordwise force dF_cd(j), as in equation (15). (This is because the blade setting angle is set to 0°.)

[0042] If the distance from the vertical axis Z to the j-th blade element of the oblique blade 14b is R2(t,j), the rotational torque dQ generated by the j-th blade element of the oblique blade 14b around the vertical axis Z is 1b (j) is expressed by equation (16). Note that in aeroelastic analysis, the distance R2(t,j) is not constant but changes with time. Alternatively, using equation (10) yields equation (17).

[0043] Adding up the rotational torques given by equation (16) for all blade elements in the longitudinal direction of the oblique wing 14b, the torque Q about the vertical axis Z of the oblique wing 14b at the azimuth Ψ is 1b (Ψ) is calculated as shown in equation (18).

[0044] Torque around the windmill rotation axis of arm 13: Q 1c (Ψ) If the drag acting on the j-th blade element of arm 13 (positive in the horizontal direction opposite to the rotor rotation) is dD3(j) and the distance from the wind turbine rotation axis to the j-th blade element of arm 13 is R3(t,j), the rotational torque dQ generated by the j-th blade element of arm 13 around the wind turbine rotation axis is 1c (j) is expressed by equation (19). Note that in aeroelastic analysis, the distance R3(t,j) is not constant but changes with time. The drag force dD3(j) of the arm 13 does not depend on the tilt angle θ2 of the movable part 21 and its angular velocity ω2, but depends on the rotational angular velocity ω1 of the wind turbine. However, the same is true for the drag forces of the movable part 21 and the over-rotation suppression inducer 22, and for clarity and to avoid complicating the expression, the dependency on ω1 is not explicitly stated. Adding up the rotational torques given by equation (19) for all blade elements in the longitudinal direction of the arm 13, the torque Q around the wind turbine rotation axis of the arm 13 at azimuth Ψ is 1c (Ψ) is calculated as shown in equation (20).

[0045] Fig. 9 shows the equation of motion of the wind turbine rotor, and Fig. 10 is an explanatory diagram of the first rotational torque calculation step. Note that here, the torque Q around the vertical axis Z due to the main wing 14a is 1a The calculation of is explained below. In the first rotational torque calculation step 30, the wind speed u of the rotor is calculated using the blade element momentum combined theory (BEM), and the rotational torque Q of the rotor is calculated from the calculated wind speed u and aerodynamic data. 1a Ask for. Blade Element Momentum Combined Theory (BEM) is used to calculate the unknown wind speed u by assuming an appropriate induced velocity coefficient a and using the thrust coefficient C calculated by momentum theory. Tm and the thrust coefficient C calculated by blade element theory Tb Repeat the calculation by gradually changing the induced velocity coefficient a until the difference between the thrust coefficient C and the induced velocity coefficient a becomes almost zero. Tm and thrust coefficient C Tb This is a method for determining the value of the induced velocity coefficient a when the values of u and u are the same, i.e., the value of u=(1-a)V∞. Blade element theory calculates aerodynamic forces from aerodynamic coefficients. When a single value of wind speed u flowing into a blade element is given, the force acting on that blade element (thrust coefficient C Tb and the output coefficient C Pb ) is obtained.

[0046] If the characteristic prediction is for a steady state (constant rotation speed), the acceleration term on the left side of the equation of motion (21) of the wind turbine rotor shown in Figure 9 is 0. Note that I1 in equation (21) is the moment of inertia around the rotation axis of the wind turbine rotor, Q total is the total wind turbine rotation torque, Q L is the load torque (generator torque), and ω1 is the rotational angular velocity of the wind turbine rotor. Note that the total wind turbine rotational torque Q total , load torque (generator torque) Q L , the relative wind speed V seen by the blade element rel , lift coefficient C L (α,Re), drag coefficient C D (α, Re) are parameters that change over time.

[0047] Fig. 10(b) shows the parameters in steady-state analysis, and Fig. 10(c) shows the parameters in unsteady-state analysis. In the steady-state analysis shown in Figure 10(b), if the wind speed u passing through a blade element in any azimuth direction in each flow tube is determined as a result of the blade element momentum coupled theory (BEM), the relative wind speed V seen by the blade element is calculated by the vector combination of the relative wind speed R1ω1, which is opposite to the moving speed given by the product of the angular velocity ω1 corresponding to the assumed constant rotation speed and the rotor radius R1, and the wind speed u. rel is decided. In addition, the relative wind speed V rel From the above, the Reynolds number Re=V based on the chord length c rel ×u / (μ / ρ) is determined (where μ is the viscosity coefficient of the fluid [air]).

[0048] In steady-state analysis, the distance (radius R1) from the rotational axis of any blade element is constant, but in unsteady analysis (i.e., aeroelastic analysis) shown in Figure 10(c), the distance (radius R1(t)) from the rotational axis of the blade element is not constant but changes because it is coupled with structural analysis. The amount of change in the position of this blade element is calculated from the deformation speed V of the object (blade element) in structural analysis. B You can get information as: Therefore, in aeroelastic analysis, as shown in Figure 10(c), the deformation velocity V B Inverse vector of (-V B) is added to the relative wind speed u seen by the blade element, and the integrated relative wind speed V seen by the blade element is rel will be a different value from that in the steady-state analysis (rigid body model). Note that Figure 10(c) is a diagram that considers only the translational speed of the change in radius R1 over time and the deformation of the blade element, but a more accurate analysis can be achieved by considering the change in pitch angle α of the blade element due to the torsional deformation of the wind turbine blade 14 and the inclination angle of the blade element (bending angle, chord angle).

[0049] Therefore, the aerodynamic coefficient data of the airfoil prepared in the aerodynamic data preparation step 31 is converted into the lift coefficient C L (α,Re) and drag coefficient C D By using (α, Re), it can be calculated by interpolation (for simplicity, the moment coefficients are omitted).

[0050] If the wind turbine blade 14 is divided into N parts in the height direction and the span length of each blade element is dl, the lift L and drag D acting on the blade element can be found from equations (22) and (23) shown in FIG. As shown in Figure 10(c), the diagonal of a rectangle with two sides consisting of the lift force L and the drag force D forms the combined aerodynamic force. Furthermore, the tangential component of this combined aerodynamic force forms the rotational force Ft that drives the blade elements in the rotor rotation direction. Therefore, when this rotational force Ft is multiplied by the rotor radius R1(t,i), it becomes the rotational torque dQ acting on one blade element. 1ai (Ψ) is given by equation (24). The rotational torque acting on a blade element in the azimuth range Ψ~Ψ+dΨ is a function of the azimuth Ψ, and the probability (temporal residence rate) that one blade element is in the azimuth range Ψ~Ψ+dΨ is dΨ / 2π.

[0051] When the wind turbine blade 14 is divided into N parts in the height direction, the rotational torque of the i-th blade element is expressed by adding a subscript i, and the rotational torque of one blade obtained by adding up the N blade elements in the height direction is expressed as Q 1a (Ψ), the torque acting on one blade in the azimuth range Ψ~Ψ+dΨ is expressed by equation (25).

[0052] Rotational torque Q of the main wing 14a 1a Similarly, the torque Q around the vertical axis Z due to the oblique blade 14b 1b and the torque Q around the vertical axis Z due to the arm 1c Therefore, the first rotational torque Q 10 is calculated using equation (26).

[0053] FIG. 11 is an explanatory diagram of the overspeed suppression portion. In the second structure data input step 41, the length L of the movable part 21 is input as design data. 21 , and the over-rotation suppression inductor length L of the over-rotation suppression inductor 22 22 Enter. The torque around the windmill rotation axis of the moving part 21 is Q 21 (Ψ), the torque around the wind turbine rotation axis of the over-rotation suppression derivative 22 is Q 22 (Ψ), the second rotational torque Q for one overspeed suppression derivative 22 20 (Ψ) is expressed by the following equation. Q 20 (Ψ)=Q 21 (Ψ)+Q 22 (Ψ)

[0054] FIG. 12 is a diagram showing the calculation of the second rotational torque. As shown in Fig. 12(a), a wind speed Ve is applied to the over-rotation suppression portion 20. Fig. 12(a) shows a quadruple multi-flow tube model in which the single-flow tube model is applied four times. In the unsteady analysis, the wind speed Ve for the over-speed suppression section 20 is Ve(t,X,Y,Z) = V∞(1-a), where V∞ is the upstream input wind speed V(y,X,Y,Z), and a represents the speed reduction rate. Also, because each over-speed suppression section 20 (B1, B2, B3) experiences a different wind speed Ve(t,X,Y,Z) at the same time, separate calculations are performed for each over-speed suppression section 20 (B1, B2, B3). In addition, the distance from the rotation center axis of any blade element of the over-rotation suppression portion 20 (radius R 21 , R 22) is constant in steady-state analysis, but in unsteady analysis, the distance from the rotation center axis of the blade element (radius R 21 (t), R 22 (t)) is not constant but changes over time. The amount of change in the position of this blade element is calculated from the structural analysis as the deformation speed V B You can get information as: In the second rotational torque calculation step 40, the rotational torque is calculated for each over-speed suppression portion 20 (B1, B2, B3), and the total rotational torque calculated for the over-speed suppression portion 20 (B1, B2, B3) is defined as the second rotational torque. However, in the following explanation, the rotational torque calculated for one over-speed suppression portion 20 will be described as the second rotational torque. Torque around the vertical axis Z by the moving part 21: Q 21 (Ψ) The drag force acting on the j-th blade element of the moving part 21 (positive in the horizontal direction opposite to the rotor rotation) is dD 21 (j, θ2, ω2), the distance from the wind turbine rotation axis to the j-th blade element of the movable part 21 is R 21 (t, j), the j-th blade element of the movable part 21 generates a rotational torque dQ around the wind turbine rotation axis. 21 (j) is expressed by equation (28). drag dD 21 (j, θ2, ω2) depends on the tilt angle θ2 of the movable part 21 and its angular velocity ω2. If we add up the rotational torques given by equation (28) for all the blade elements in the longitudinal direction of the movable part 21, we get the torque Q around the wind turbine rotation axis of the movable part 21 at the azimuth Ψ. 21 (Ψ) is calculated as in equation (29). In unsteady analysis, the drag force dD 21 (j,θ2,ω2)=T 21 (V(t)) and the drag force dD 21 (j, θ2, ω2) changes depending on the input wind speed V. Here, T 21 is a function (based on blade element theory) that converts the upstream wind speed V(t,X,Y,Z) into the drag acting on any blade element j of the movable part 21. In addition, the tilt angle θ2 of the movable part 21 and its angular velocity ω2 change over time depending on the deformation amount of the structure calculated by the structural analysis system 60.

[0055] Torque around the wind turbine rotation axis of the over-rotation suppression derivative 22: Q 22 (Ψ) The drag acting on the jth blade element of the over-rotation suppression derivative 22 (positive in the horizontal direction opposite to the rotor rotation) is dD 22 (j, θ2, ω2), the distance from the wind turbine rotation axis to the over-rotation suppression inductor 22 is R 22 (t, j), the j-th blade element of the over-rotation suppression inductor 22 generates a rotational torque dQ around the wind turbine rotation axis. 22 (j) is expressed by equation (30). In addition, in equation (30), the effect dM of the moment caused by the aerodynamic force around the aerodynamic center of the j-th blade element of the over-rotation suppression inducer 22 (the position 1 / 4 of the chord length of the over-rotation suppression inducer 22 from the leading edge of the over-rotation suppression inducer 22) 22 (j,θ2,ω2) is added. drag dD 22 (j, θ2, ω2) depends on the inclination angle θ2 of the over-rotation suppression inductor 22 and its angular velocity ω2. Note that the effect of the moment dM 22 (j, θ2, ω2) also depends on the inclination angle θ2 and the angular velocity ω2 of the over-rotation suppression inductor 22. As with the drag, this is because the inclination angle θ2 and the angular velocity ω2 are related to the calculation of the relative wind speed used to calculate the moment, and details are omitted here. For all blade elements in the longitudinal direction of the over-rotation suppression inducer 22, the torque Q around the wind turbine rotation axis of the over-rotation suppression inducer 22 at the azimuth Ψ is calculated by adding up the rotation torques given by equation (30). 22 (Ψ) is calculated as shown in equation (31). In the unsteady analysis, the drag force dD 22 (j,θ2,ω2)=T 22 (V(t)) and the drag force dD 22 (j, θ2, ω2) changes depending on the input wind speed V. Here, T 22 is a function (based on blade element theory) that converts the upstream wind speed V(t,X,Y,Z) into the drag acting on any blade element j of the over-rotation suppression inducer 22. In addition, the tilt angle θ2 of the over-rotation suppression inducer 22 and its angular velocity ω2 change over time depending on the deformation amount of the structure calculated by the structural analysis system 60. Therefore, the second rotation torque Q by the overspeed suppression portion 20 20 is calculated using equation (32).

[0056] In the step 50 for calculating the entire wind turbine rotational torque, as shown in equation (33), the first rotational torque Q of the wind turbine blade 14 shown in equation (26) is calculated. 10 and the second rotational torque Q of the overspeed suppression portion 20 shown in equation (32). 20 The total rotation torque Q of a vertical axis wind turbine is calculated from total Calculate. [Industrial Applicability]

[0057] The aeroelastic analysis method and program for a vertical axis wind turbine equipped with an over-speed suppression mechanism, and the aeroelastic analysis system for a vertical axis wind turbine equipped with an over-speed suppression mechanism of the present invention can evaluate the performance of a vertical axis wind turbine equipped with an over-speed suppression mechanism, and can be used for optimal design of a vertical axis wind turbine equipped with an over-speed suppression mechanism. [Explanation of symbols]

[0058] 10 Windmill main body part 11 Base 11a Legs 11b Storage section 12 Rotating part 13 Arm 13a Arm axis 14 Windmill blade 14a Main wing 14b oblique wing 14c Curved section 20 Overspeed suppression part 21 Moving parts 22 Hyperrotation suppression derivatives 50 Input Style Database 60 Structural Analysis System X horizontal axis Z vertical axis Q 10 First rotational torque due to wind turbine blade 14 with blade number M Q1 First rotation torque for 11 wind turbine blades 14 Q 1a(Ψ) Torque around the vertical axis Z due to the main wing 14a when it is within a small range of azimuth Ψ (azimuth angle) (set as ΔΨ = 1 degree) Q 1b (Ψ) Torque around the vertical axis Z due to the tilted blade 14b when it is within a small range of azimuth Ψ (set as ΔΨ = 1 degree) Q 1c (Ψ) Torque around the vertical axis Z due to the arm when it is within a small azimuth Ψ (azimuth angle) range (set ΔΨ = 1 degree) Q 20 The second rotation torque by the overspeed suppression portion 20 where the number of the overspeed suppression portions 20 is M Q21 overspeed suppression part 20 second rotation torque Q 21 (Ψ) Torque around the wind turbine rotation axis of the movable part 21 when it is within a certain small range of azimuth Ψ (azimuth angle) (set as ΔΨ = 1 degree) Q 22 (Ψ) Torque around the wind turbine rotation axis of the over-rotation suppression inducer 22 when it is within a certain small azimuth Ψ (azimuth angle) range (set as ΔΨ = 1 degree) Q total Overall wind turbine rotation torque

Claims

1. It consists of a wind turbine main body and an over-rotation suppression part. The wind turbine body portion is a base having a power generating unit; a rotating part that rotates about a vertical axis relative to the base part; a plurality of wind turbine blades connected to the rotating part via arms and rotating around the vertical axis; Equipped with The over-rotation suppression portion is a movable part for suppressing excessive rotation, the movable part being provided on the arm and rotatable around an arm axis connecting the rotating part and the wind turbine blade or around an axis parallel to the arm axis; an over-rotation suppression inductor that is provided on the movable part, tilts the movable part around the arm axis by the action of centrifugal force, aerodynamic force, and gravity that are generated when the wind turbine blade rotates, and returns the movable part to its initial state when the wind turbine blade stops rotating; Equipped with A method for analyzing aeroelasticity of a vertical axis wind turbine equipped with an over-rotation suppression mechanism, comprising the steps of: a first rotational torque calculation step of calculating a first rotational torque around the rotating part of the wind turbine main body; a second rotational torque calculation step of calculating a second rotational torque around the rotating portion of the over-rotation suppression portion; an entire wind turbine rotation torque calculation step of calculating an entire wind turbine rotation torque of the vertical axis wind turbine from the first rotation torque and the second rotation torque; and in the first rotational torque calculation step, a total rotational torque for each of the wind turbine blades calculated using a fluctuating wind speed that changes depending on the azimuth of each of the wind turbine blades and a deformation speed obtained from the deformation amount of the wind turbine blade due to the action of the aerodynamic force, gravity, and centrifugal force is set as the first rotational torque; In the second rotation torque calculation step, the total rotation torque for each of the over-speed suppression portions calculated using a fluctuating wind speed that changes depending on the azimuth of each of the over-speed suppression portions and a deformation speed obtained from the deformation amount of each of the over-speed suppression portions due to the action of the aerodynamic force, gravity, and centrifugal force is set as the second rotation torque. A method for analyzing aeroelasticity of a vertical axis wind turbine equipped with an over-rotation suppression mechanism, characterized by the above.

2. an input step of receiving input of aerodynamic data related to blade shapes of the wind turbine main body portion and the over-rotation suppression portion, first structural data related to a structure of the wind turbine main body portion, and second structural data related to a structure of the over-rotation suppression portion, If the first rotational torque calculated in the first rotational torque calculation step does not become a predetermined rotational torque, the first structure data in the input step is changed.

2. The method for analyzing aeroelasticity of a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to claim 1.

3. an input step of receiving input of aerodynamic data related to blade shapes of the wind turbine main body portion and the over-rotation suppression portion, first structural data related to a structure of the wind turbine main body portion, and second structural data related to a structure of the over-rotation suppression portion, If the second rotational torque calculated in the second rotational torque calculation step does not become a predetermined rotational torque, the second structure data in the input step is changed.

2. The method for analyzing aeroelasticity of a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to claim 1.

4. an input step of receiving input of aerodynamic data related to blade shapes of the wind turbine main body portion and the over-rotation suppression portion, first structural data related to a structure of the wind turbine main body portion, and second structural data related to a structure of the over-rotation suppression portion, If the entire wind turbine rotational torque calculated in the entire wind turbine rotational torque calculation step does not become a predetermined rotational torque, at least one of the aerodynamic data, the first structural data, and the second structural data in the input step is changed.

2. The method for analyzing aeroelasticity of a vertical axis wind turbine equipped with an over-rotation suppression mechanism according to claim 1.

5. It consists of a wind turbine main body and an over-rotation suppression part. The wind turbine body portion is a base having a power generating unit; a rotating part that rotates about a vertical axis relative to the base part; a plurality of wind turbine blades connected to the rotating part via arms and rotating around the vertical axis; Equipped with The over-rotation suppression portion is a movable part for suppressing excessive rotation, the movable part being provided on the arm and rotatable around an arm axis connecting the rotating part and the wind turbine blade or around an axis parallel to the arm axis; an over-rotation suppression inductor that is provided on the movable part, tilts the movable part around the arm axis by the action of centrifugal force, aerodynamic force, and gravity that are generated when the wind turbine blade rotates, and returns the movable part to its initial state when the wind turbine blade stops rotating; Equipped with A program for performing an aeroelastic analysis method for a vertical axis wind turbine equipped with an over-rotation suppression mechanism, On the computer, a first rotational torque calculation step of calculating a first rotational torque around the rotating part of the wind turbine main body; a second rotational torque calculation step of calculating a second rotational torque around the rotating portion of the over-rotation suppression portion; an entire wind turbine rotation torque calculation step of calculating an entire wind turbine rotation torque of the vertical axis wind turbine from the first rotation torque and the second rotation torque; Execute in the first rotational torque calculation step, a total rotational torque for each of the wind turbine blades calculated using a fluctuating wind speed that changes depending on the azimuth of each of the wind turbine blades and a deformation speed obtained from the deformation amount of the wind turbine blade due to the action of the aerodynamic force, gravity, and centrifugal force is set as the first rotational torque; In the second rotation torque calculation step, the total rotation torque for each of the over-speed suppression portions calculated using a fluctuating wind speed that changes depending on the azimuth of each of the over-speed suppression portions and a deformation speed obtained from the deformation amount of each of the over-speed suppression portions due to the action of the aerodynamic force, gravity, and centrifugal force is set as the second rotation torque. A program characterized by:

6. The computer, an input step of receiving input of aerodynamic data relating to blade shapes of the wind turbine main body portion and the over-rotation suppression portion, first structural data relating to the structure of the wind turbine main body portion, and second structural data relating to the structure of the over-rotation suppression portion; Execute 6. The program according to claim 5, for executing the first rotational torque calculation step and the second rotational torque calculation step using the aerodynamic data, the first structural data, and the second structural data received in the input step.

7. It consists of a wind turbine main body and an over-rotation suppression part. The wind turbine body portion is a base having a power generating unit; a rotating part that rotates about a vertical axis relative to the base part; a plurality of wind turbine blades connected to the rotating part via arms and rotating around the vertical axis; Equipped with The over-rotation suppression portion is a movable part for suppressing excessive rotation, the movable part being provided on the arm and rotatable around an arm axis connecting the rotating part and the wind turbine blade or around an axis parallel to the arm axis; an over-rotation suppression inductor that is provided on the movable part, tilts the movable part around the arm axis by the action of centrifugal force, aerodynamic force, and gravity that are generated when the wind turbine blade rotates, and returns the movable part to its initial state when the wind turbine blade stops rotating; Equipped with An aeroelastic analysis system for a vertical axis wind turbine equipped with an over-rotation suppression mechanism, a first rotational torque calculation means for calculating a first rotational torque around the rotating part of the wind turbine main body; a second rotational torque calculation means for calculating a second rotational torque around the rotating portion of the over-rotation suppression portion; an overall wind turbine rotation torque calculation means for calculating an overall wind turbine rotation torque of the vertical axis wind turbine from the first rotation torque and the second rotation torque; and the first rotational torque calculation means calculates a total rotational torque for each of the wind turbine blades using a fluctuating wind speed that changes depending on the azimuth of each of the wind turbine blades and a deformation speed obtained from the deformation amount of the wind turbine blade caused by the action of the aerodynamic force, gravity, and centrifugal force, and defines the total rotational torque for each of the wind turbine blades as the first rotational torque; The second rotational torque calculation means calculates a total rotational torque for each of the over-rotation suppression portions using a fluctuating wind speed that changes depending on the azimuth of each of the over-rotation suppression portions and a deformation speed obtained from the deformation amount of each of the over-rotation suppression portions due to the action of the aerodynamic force, gravity, and centrifugal force, and defines the total rotational torque for each of the over-rotation suppression portions as the second rotational torque. This is an aeroelastic analysis system for a vertical axis wind turbine equipped with an over-rotation suppression mechanism.

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