Wind turbine tower tuning vibration reduction device and design and installation method

Abstract

The present application proposes a wind turbine tower tuning vibration reduction device and a design and installation method, wherein the vibration reduction device includes a mass ball block and a damper; wherein the wind turbine tower includes a tower, the mass ball block is located in the top of the tower, and its upper and lower ends are connected to the top and bottom of the tower through an upper cable and a lower cable respectively; the damper includes a plurality of dampers that are circumferentially arranged outside the mass ball block and connected to the inner wall of the tower. The present application arranges a vibration reduction device on the wind turbine tower, and transfers the vibration energy of the wind turbine tower to the vibration reduction device through passive resonance, thereby suppressing the vibration of the wind turbine tower.

Description

Technical Field

[0001] The present application relates to the field of wind power technology, and in particular to a wind turbine tower tuning and vibration reduction device and a design and installation method. Background Art

[0002] In recent years, with the increase in people's demand for energy and the enhancement of awareness of environmental protection, wind energy has begun to be widely used. As the scale of offshore wind turbine structures increases, the requirements for structural safety have become higher. With the increase in the power generation of wind turbines, the blades of wind turbines are getting longer and longer, and the towers are getting higher and higher. The flexible characteristics of wind turbine towers are becoming more and more prominent, and have gradually approached the frequency of external loads such as wind and waves, which can easily cause resonance of wind turbine towers. Excessive vibration not only reduces the fatigue life of the tower itself, but also has a great impact on the performance of the generator set, which will reduce the overall life of the wind turbine and reduce the power generation efficiency. Therefore, the development of wind turbines in the direction of large megawatts must solve the problem of excessive vibration amplitude of the tower. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the purpose of this application is to propose a wind turbine tower tuning vibration reduction device and a design and installation method, by arranging a vibration reduction device on the wind turbine tower, the vibration energy of the wind turbine tower is transferred to the vibration reduction device through passive resonance, thereby suppressing the vibration of the wind turbine tower.

[0005] In order to achieve the above-mentioned purpose, the present application proposes a wind turbine tower tuning and vibration reduction device, comprising:

[0006] A mass ball block; wherein the wind turbine tower comprises a tower, the mass ball block is located in the top of the tower, and the upper and lower ends are connected to the top and bottom of the tower through an upper cable and a lower cable respectively;

[0007] The damper comprises a plurality of dampers which are circumferentially arranged outside the mass ball block and connected to the inner wall of the tower.

[0008] In some embodiments, the number of the dampers is eight and they are symmetrically distributed relative to the mass ball block, and the eight dampers are all in the same cross-section.

[0009] In some embodiments, the wind turbine tower includes a nacelle and an impeller at the top of the tower; wherein the impeller is rotatably mounted on the nacelle.

[0010] In some embodiments, the dampers are all viscous dampers.

[0011] In some embodiments, a parameter design and installation method of a prestressed tuning vibration reduction device is proposed, comprising the following steps:

[0012] Determine the structural parameters of the wind turbine tower including the height of the wind turbine tower, the mass of the nacelle and the impeller, and establish a single degree of freedom system model of the wind turbine tower, and obtain a normalized dynamic equation expression after analysis and processing;

[0013] Install the vibration reduction device described in any of the above embodiments on a wind turbine tower; establish a dual-degree-of-freedom system model of the wind turbine tower, analyze and calculate the positional relationship between the vibration reduction device and the tower when vibrating, and derive a dual-degree-of-freedom system dynamic equation based on the D'Alembert principle;

[0014] Optimizing the parameters of the vibration reduction device based on the vibration reduction principle to find the optimal frequency ratio between the natural frequency of the vibration reduction device and the natural frequency of the wind turbine tower;

[0015] The dynamic coefficient amplitude at the optimal frequency ratio is calculated and the parameters of the wind turbine tower after the vibration reduction device is applied are obtained.

[0016] In some embodiments, when establishing a single degree of freedom system model of the wind turbine tower, based on the principle of structural dynamics, the nacelle and the impeller are simplified to the concentrated mass M at the top of the wind turbine tower, and the tower is simplified to a vertical cantilever column, and the vertical cantilever column has a distributed mass m(z) and a stiffness EI(z) along the height direction of the tower; and the normalized dynamic equation is expressed as follows:

[0017]

[0018] where x s (t) is the horizontal x-direction displacement of the top of the wind turbine tower at any time; The first-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the second-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; m s is the generalized quality; c s is the generalized damping; k s is the generalized stiffness; F(t) is the equivalent generalized load.

[0019] In some embodiments, when establishing a dual-degree-of-freedom system model of the wind turbine tower, the wind turbine tower and the vibration reduction device are simplified to one degree of freedom respectively. According to the geometric relationship between the angle θ1 between the central axis of the tower and the vertical direction, the angle θ2 between the upper cable and the vertical direction, and the angle θ3 between the lower cable and the vertical direction, the relative displacement q(t) between the vibration reduction device and the inner wall of the tower is expressed as:

[0020]

[0021] Wherein, h is the vertical distance from the top of the wind turbine tower to the suspension point of the mass ball block, and H is the height of the wind turbine tower; xs (t) is the horizontal x-direction displacement of the top of the wind turbine tower at any time; x d (t) is the horizontal x-direction displacement of the mass ball at any moment.

[0022] In some embodiments, the horizontal vibration amplitude of the wind turbine tower top and the vibration reduction device is small relative to the wind turbine tower height H and the suspension height (Hh); the geometric relationship between the angle θ1 between the tower centerline and the vertical direction, the angle θ2 between the upper cable and the vertical direction, and the angle θ3 between the lower cable and the vertical direction is as follows:

[0023]

[0024] Wherein: h is the vertical distance from the top of the wind turbine tower to the suspension point of the mass ball block, H is the height of the wind turbine tower; x s (t) is the horizontal x-direction displacement of the top of the wind turbine tower at any time; x d (t) is the horizontal x-direction displacement of the mass ball at any moment.

[0025] In some embodiments, the dynamic equation of the dual-degree-of-freedom system is as follows:

[0026]

[0027] where x s is the horizontal x-direction displacement of the top of the wind turbine tower at any time; The first-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the second-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; m s is the generalized quality; c s is the generalized damping; k s is the generalized stiffness; F(t) is the equivalent generalized load; θ1 is the angle between the central axis of the tower and the vertical direction, θ2 is the angle between the upper cable and the vertical direction, and θ3 is the angle between the lower cable and the vertical direction; m d is the mass of the vibration reduction device, k d is the stiffness of the vibration reduction device, c d is the damping coefficient of the vibration reduction device, f is the prestress of the cable; q is the relative displacement between the vibration reduction device and the inner wall of the tower; is the first-order derivative of the relative displacement between the vibration reduction device and the inner wall of the tower; g is the gravitational acceleration.

[0028] In some embodiments, when the ratio of the natural frequency of the vibration reduction device to the natural frequency of the wind turbine tower is an optimal frequency ratio, the amplitude of the dynamic coefficient of the wind turbine tower is minimum.

[0029] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0031] Figure 1 is a top view schematic diagram of a wind turbine tower tuning and vibration reduction device proposed in one embodiment of the present application;

[0032] Figure 2 yes Figure 1 Installation diagram of the fan tower;

[0033] Figure 3 is a schematic diagram of the positional relationship between the vibration reduction device and the wind turbine tower when vibrating, as proposed in one embodiment of the present application;

[0034] Figure 4 It is a flow chart of a parameter design and installation method of a prestressed tuning vibration reduction device proposed in one embodiment of the present application;

[0035] In the figure, 1. mass ball block; 2. damper; 3. tower; 4. impeller; 5. cabin; 6. upper rope; 7. lower rope; 8. foundation. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0037] See also Figure 1-Figure 2 The present application proposes a wind turbine tower tuning vibration reduction device, comprising a mass ball block 1, a damper 2, an upper cable 6 and a lower cable 7; wherein the wind turbine tower is arranged above a foundation 8, and the wind turbine tower comprises a tower 3, a nacelle 5 and an impeller 4; wherein the nacelle 5 is arranged at the top of the tower 3, and the impeller 4 is rotatably mounted on the nacelle 5.

[0038] In this embodiment, the mass ball block 1 can be understood as a spherical mass block with a certain mass, which is located inside the tower 3 and set at a suitable position on the top of the tower 3; the upper end of the mass ball block 1 is connected to the top of the tower 3 through the upper cable 6, and the lower end of the mass ball block 1 is connected to the bottom of the tower 3 through the lower cable 7. By adjusting the tension of the upper cable 6 and the lower cable 7, a certain prestress is generated in the upper cable 6 and the lower cable 7. It can be known that the upper cable 6 and the lower cable 7 are an integrated rope, which is a rope such as Figure 1 Therefore, when the mass ball block 1 is connected to the upper rope 6 and the lower rope 7, the upper rope 6 and the lower rope 7 are in a tensioned state and have a certain prestress; when the mass ball block 1 deviates from the center position due to vibration, the mass ball block 1 and the integrated rope will form an angle, and the horizontal component of the integrated rope tension will provide reverse tension to the mass ball block 1, thereby suppressing vibration.

[0039] The damper 2 in this embodiment includes a plurality of dampers 2 which are circumferentially arranged outside the mass ball block 1 and connected to the inner wall of the tower 3. Figure 1 As shown, the damper 2 may be a viscous damper, and the number may be eight, and the two ends of the eight dampers 2 are respectively connected to the outer side of the mass ball block 1 and the inner wall of the tower 3, and the dampers 2 are symmetrically distributed relative to the mass ball block 1 and are located on the outer side of the mass ball block 1. Preferably, the eight dampers 2 are all in the same cross section. When the wind turbine tower vibrates, the mass ball block 1 vibrates in the opposite direction relative to the wind turbine tower due to inertia, thereby reducing the vibration of the wind turbine tower, playing a buffering and tuning role, and preventing the mass ball block 1 from hitting the inner wall of the tower 3.

[0040] In some embodiments, Figure 4 A parameter design and installation method of a prestressed tuned vibration reduction device is proposed, comprising the following steps:

[0041] S1: Determine the structural parameters of the wind turbine tower including the height of the wind turbine tower, the mass of the nacelle 5 and the impeller 4, and establish a single degree of freedom system model of the wind turbine tower, and obtain a normalized dynamic equation expression after analysis and processing;

[0042] S2: installing the vibration reduction device in any of the above embodiments on the wind turbine tower; and establishing a dual-degree-of-freedom system model of the wind turbine tower, analyzing and calculating the positional relationship between the vibration reduction device and the tower during vibration, and deriving a dual-degree-of-freedom system dynamics equation based on the D'Alembert principle;

[0043] S3: Optimizing the parameters of the vibration reduction device based on the vibration reduction principle to obtain the optimal frequency ratio of the natural frequency of the vibration reduction device to the natural frequency of the wind turbine tower;

[0044] S4: Calculate the dynamic coefficient amplitude at the optimal frequency ratio and obtain the parameters of the wind turbine tower after the vibration reduction device is applied.

[0045] Specifically, when the single degree of freedom system model of the wind turbine tower is established in S1, the nacelle 5 and the impeller 4 are simplified to the concentrated mass M at the top of the wind turbine tower based on the principle of structural dynamics, and the tower 3 is simplified to a vertical cantilever column. The vertical cantilever column has a distributed mass m(z) and a stiffness EI(z) along the height direction of the tower 3; and the normalized dynamic equation is expressed as follows:

[0046]

[0047] where x s (t) is the horizontal x-direction displacement of the top of the wind turbine tower at any time; The first-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the second-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; m s is the generalized quality; c s is the generalized damping; k s is the generalized stiffness; F(t) is the equivalent generalized load.

[0048] The known wind turbine tower structure includes a tower 3 and a nacelle 5 and an impeller 4 at the top of the tower 3. The mass of a horizontal axis wind turbine is mainly concentrated in the nacelle 5 and the impeller 4 at the top of the tower. When performing structural dynamics calculations, the nacelle 5 and the impeller 4 can be simplified to the concentrated mass M at the top of the tower, and the tower 3 can be simplified to a vertical cantilever column. The cantilever column has a distributed mass m(z) along the z direction of the tower 3 height, and the stiffness is EI(z). According to the principle of structural dynamics, the overall structure of the wind turbine can be simplified to a single degree of freedom system.

[0049] Specifically, in S2, after the vibration reduction device is connected to the tower 3, the wind turbine tower and the vibration reduction device can be simplified to one degree of freedom respectively, that is, a two-degree-of-freedom system. The positional relationship between the vibration reduction device and the tower during vibration is as follows: Figure 3 As shown in the figure, the angle θ1 between the central axis of the tower 3 and the vertical direction, the angle θ2 between the upper cable 6 and the vertical direction, the angle θ3 between the lower cable 7 and the vertical direction, h is the vertical distance from the top of the wind turbine tower to the hanging point of the mass ball block, and H is the height of the wind turbine tower; x s (t) is the horizontal x-direction displacement of the top of the wind turbine tower at any time; d (t) is the horizontal x-direction displacement of the mass ball at any time. Since the horizontal vibration amplitude of the tower top and the vibration reduction device is small relative to the tower height H and the suspension height (Hh), the geometric relationship between θ1, θ2, and θ3 can be obtained as follows:

[0050]

[0051] The relative displacement q(t) between the vibration reduction device and the inner wall of the tower 3 can be expressed as follows:

[0052]

[0053] According to the D'Alembert principle, the fan dynamics equation of the double-degree-of-freedom system with an additional vibration reduction device can be expressed as

[0054]

[0055] where x s is the horizontal x-direction displacement of the top of the wind turbine tower at any time; The first-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the second-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; m s is the generalized quality; c s is the generalized damping; k s is the generalized stiffness; F(t) is the equivalent generalized load; θ1 is the angle between the central axis of the tower 3 and the vertical direction, θ2 is the angle between the upper cable 6 and the vertical direction, and θ3 is the angle between the lower cable 7 and the vertical direction; m d is the mass of the vibration reduction device, k d is the stiffness of the vibration reduction device, c d is the damping coefficient of the vibration reduction device, f is the prestress of the cable; q is the relative displacement between the vibration reduction device and the inner wall of the tower 3; is the first-order derivative of the relative displacement between the vibration reduction device and the inner wall of the tower 3; g is the gravitational acceleration.

[0056] In S3, according to the vibration reduction principle, there is an optimal frequency ratio between the natural frequency of the vibration reduction device and the natural frequency of the wind turbine tower. When the optimal frequency ratio is reached, the amplitude of the wind turbine tower is minimized. The optimal frequency ratio is sought by optimizing the parameters of the vibration reduction device. The relevant parameters of the vibration reduction device include the tower height, the generalized stiffness of the wind turbine tower, the suspension height of the vibration reduction device, the mass, stiffness and damping of the vibration reduction device, and the prestress of the integrated rope.

[0057] In S4, the dynamic coefficient amplitude when the frequency ratio reaches the optimal value is finally calculated. The smaller the dynamic coefficient amplitude at this time, the smaller the tower amplitude is, and the smaller the tower amplitude is.

[0058] The present application can accurately adjust the vibration frequency of the wind turbine tower and the vibration reduction device, and transfer as much vibration energy as possible to the tuning vibration reduction device, thereby effectively reducing the vibration of the wind turbine tower and solving the problem of excessive vibration amplitude of the tower when the wind turbine develops in the direction of large megawatts.

[0059] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0060] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0062] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A parameter design and installation method for a prestressed tuning vibration reduction device, characterized in that: The following steps are involved: Determine the structural parameters of the wind turbine tower including the height of the wind turbine tower, the mass of the nacelle and the impeller, and establish a single degree of freedom system model of the wind turbine tower, and obtain a normalized dynamic equation expression after analysis and processing; When establishing the single degree of freedom system model of the wind turbine tower, based on the principle of structural dynamics, the nacelle and the impeller are simplified to the concentrated mass M at the top of the wind turbine tower, and the tower of the vibration reduction device is simplified to a vertical cantilever column. The vertical cantilever column has a distributed mass m(z) and a stiffness EI(z) along the height direction of the tower; and the normalized dynamic equation is expressed as follows: ； in is the horizontal x-direction displacement of the top of the wind turbine tower at any time; The first-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the second-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the generalized quality; is generalized damping; is the generalized stiffness; is the equivalent generalized load; A vibration reduction device is installed on a wind turbine tower, wherein the vibration reduction device comprises a mass ball block and a damper; wherein the wind turbine tower comprises the tower; the mass ball block is located inside the top of the tower, and its upper and lower ends are connected to the top and bottom of the tower through an upper cable and a lower cable respectively; the damper comprises a plurality of circumferentially arranged outside the mass ball block and connected to the inner wall of the tower; A dual-degree-of-freedom system model of the wind turbine tower is established, and a dynamic equation of the dual-degree-of-freedom system is derived based on the D'Alembert principle after analyzing and calculating the positional relationship between the vibration reduction device and the tower during vibration. When establishing the double-degree-of-freedom system model of the wind turbine tower, the wind turbine tower and the vibration reduction device are simplified to one degree of freedom respectively, and the angle between the central axis of the tower and the vertical direction is , the angle between the upper rope and the vertical direction , the angle between the lower rope and the vertical direction The geometric relationship between the vibration reduction device and the inner wall of the tower tube is It is expressed as: in, is the vertical distance from the top of the wind turbine tower to the suspension point of the mass ball block, is the wind turbine tower height; is the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the horizontal x-direction displacement of the mass ball at any time; The horizontal vibration amplitude of the top of the wind turbine tower and the vibration reduction device is relative to the height of the wind turbine tower. and suspension height The angle between the central axis of the tower and the vertical direction is , the angle between the upper rope and the vertical direction , the angle between the lower rope and the vertical direction The geometric relationship is as follows: in; is the vertical distance from the top of the wind turbine tower to the suspension point of the mass ball block, is the wind turbine tower height; is the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the horizontal x-direction displacement of the mass ball at any time; The dynamic equation of the dual-freedom system is as follows: in is the horizontal x-direction displacement of the top of the wind turbine tower at any time; The first-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the second-order derivative of the horizontal x-direction displacement of the top of the wind turbine tower at any time; is the generalized quality; is generalized damping; is the generalized stiffness; is the equivalent generalized load; is the angle between the central axis of the tower and the vertical direction, is the angle between the upper rope and the vertical direction, is the angle between the lower rope and the vertical direction; is the mass of the vibration damping device, is the stiffness of the vibration reduction device, is the damping coefficient of the vibration reduction device, is the prestress of the cable; q is the relative displacement between the vibration reduction device and the inner wall of the tower; is the first-order derivative of the relative displacement between the vibration reduction device and the inner wall of the tower; g is the gravitational acceleration; Based on the vibration reduction principle, the parameters of the vibration reduction device are optimized to seek the optimal frequency ratio of the natural frequency of the vibration reduction device to the natural frequency of the wind turbine tower; when the ratio of the natural frequency of the vibration reduction device to the natural frequency of the wind turbine tower is the optimal frequency ratio, the amplitude of the dynamic coefficient of the wind turbine tower is the smallest; The dynamic coefficient amplitude at the optimal frequency ratio is calculated and the parameters of the wind turbine tower after the vibration reduction device is applied are obtained.

2. The parameter design and installation method according to claim 1, characterized in that: There are eight dampers, which are symmetrically distributed relative to the mass ball block, and the eight dampers are all in the same cross section.

3. The parameter design and installation method according to claim 1 or 2, characterized in that: The wind turbine tower comprises a nacelle and an impeller at the top of the tower; wherein the impeller is rotatably mounted on the nacelle.

4. The parameter design and installation method according to claim 3, characterized in that: The dampers are all viscous dampers.

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