A vibration reduction device for wind turbine blades

Abstract

The invention discloses a vibration reduction device for a blade of a wind turbine generator, comprising a first packaging box, the first packaging box is arranged on the blade, and third magnets are arranged at both ends of the first packaging box; a vibration reduction mechanism is arranged in the middle of the first packaging box; the vibration reduction mechanism comprises a mass block and a second packaging box; the second packaging box and the mass block are slidably connected; magnet assemblies are connected at both sides of the mass block; the magnet assembly and the third magnet are connected by a spring, and the magnet assembly and the third magnet repel each other; during the vibration of the blade, according to Lenz's law, the mass block absorbs the kinetic energy of the blade and moves left and right along the second packaging box, resulting in continuous changes in the magnetic flux in the second packaging box, generating an Ampere force opposite to the movement direction of the mass block, preventing the mass block from being displaced and generating current, and accelerating the energy dissipation of the blade, thereby further improving the vibration reduction effect of the blade and reducing the damage and breakage of the blade.

Description

Technical Field

[0001] The invention belongs to the technical field of wind power generation blade vibration reduction, and in particular relates to a vibration reduction device for wind power generator blades. Background Art

[0002] Ensuring the safe operation of wind turbines is the top priority in the wind power industry. With the shortage of resources and the increasingly urgent demand for new energy, wind turbines have been put into use on a large scale in many places across the country. Wind loads in different environments have also led to various vibration problems, among which blade vibration is the most obvious. The alternating stress of blade vibration can cause fatigue cracks in the blades, thus causing damage to the blades. According to statistics from the World Wind Energy Association, since the 1970s, the total number of wind turbine accidents in the world is 1,093, of which 220 were caused by blade damage, accounting for 20.1%. It can be seen that the anti-flutter technology of wind turbine blades is one of the problems that need to be solved in the design of large wind turbines.

[0003] Large wind turbines are complex fluid-solid coupling systems. The thin and long blades have infinite bending and torsional vibration modes. The randomly flowing air acts on the blades, which not only generates aerodynamic force to drive the wind rotor to rotate, but also causes aeroelastic problems in the wind turbine, including static divergence, flutter, and the coupling stability of the wind rotor and the tower. Among them, the flutter of wind turbine blades is an unstable self-excited vibration. When the blades deform or move under the action of the flow field, the deformation or movement of the blades in turn affects the flow field, thereby changing the load size and distribution of the fluid on the blade surface. The blades "flap" under the action of aerodynamic force, gravity and centrifugal force, that is, the bending vibration of the blades in the direction perpendicular to the rotation plane, which can easily cause the wind turbine to shut down and even collapse the tower. Examples of blade breakage are common. The "flashing" of wind turbine blades greatly damages the service life of wind turbines, destroys the safe operation of wind turbines, and seriously hinders the development of new energy.

[0004] At present, the mainstream vibration reduction method for wind turbine blades is still the built-in TMD module based on passive tuning vibration reduction. The principle of TMD control is to add a mass block to the system, and maintain the balance of the wind turbine through the reverse inertial force generated when the mass block slides forward. At the same time, the mass block can absorb the kinetic energy of the wind turbine structure and slow down the vibration amplitude of the blade. In theory, when the structural frequency of the mass block is consistent with the frequency of the external wind load, the blade can be made non-vibrating and all the vibrations are absorbed by the mass block. However, the problem is that in order to achieve a better vibration absorption effect, the mass block must be large, which is costly on the one hand, and the blade bearing capacity has an upper limit on the other hand. Moreover, the vibration absorber is only effective when the structural frequency is consistent with the load frequency. Once the environmental load changes or the frequency difference is large, the effect of the vibration absorber will be very limited. In addition, the effect of the vibration absorber depends entirely on the natural frequency. When the natural frequency is consistent with the wind load frequency, the vibration transmitted to the blade by the load will be completely absorbed by the mass block, which is called the anti-resonance effect. At this time, the blade is non-vibrating and the mass block vibrates violently, but the problem that follows is that the passive vibration absorber is also easily damaged at this time. Summary of the invention

[0005] The purpose of the present invention is to provide a vibration reduction device for wind turbine blades, so that the kinetic energy of wind turbine blade vibration can be converted into other energy forms for dissipation, thereby solving the problem of wind turbine blade vibration causing blade damage mentioned in the above background technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a vibration reduction device for a blade of a wind turbine generator, comprising a first packaging box, the first packaging box being arranged on the blade of the wind turbine generator, and third magnets being arranged at both ends of the first packaging box; a vibration reduction mechanism being arranged in the middle of the first packaging box; and springs being connected to both sides of the vibration reduction mechanism;

[0008] The vibration reduction mechanism includes a mass block and a second packaging box; the mass block is arranged in the second packaging box, and the second packaging box and the mass block are slidably connected; magnet assemblies are connected to both sides of the mass block; the magnet assembly is connected to the third magnet through a spring, and the magnet assembly and the third magnet repel each other.

[0009] Furthermore, the magnet assembly includes a first magnet and a second magnet; the first magnet is connected to the mass block; the first magnet is connected to the second magnet through a connecting rod, the magnetic poles of the first magnet and the second magnet repel each other and can generate magnetic lines of force perpendicular to the connecting rod; the second magnet is connected to the third magnet through a spring, and the second magnet and the third magnet repel each other.

[0010] Furthermore, a locking cap is provided at the end of the second magnet to prevent the second magnet from sliding off.

[0011] Furthermore, one end of the spring is connected to the lock cap, and the other end is connected to the third magnet.

[0012] Furthermore, the connecting rod, the locking cap and the mass block are all made of high-density alloy.

[0013] Furthermore, the second packaging box is made of copper.

[0014] Furthermore, a temperature sensor is installed on the outer wall of the second packaging box.

[0015] Furthermore, heating devices are connected to both ends of the spring, the temperature sensor is connected to the input end of the controller, and the heating device is connected to the output end of the controller.

[0016] On the other hand, the present invention further provides a wind turbine, comprising blades and the vibration reduction device, wherein the vibration reduction device is mounted on the blades and is perpendicular to the rotation plane of the blades.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: in the present invention, a first packaging box is arranged on the blade of the wind turbine, and third magnets are arranged at both ends of the first packaging box; a vibration reduction mechanism is arranged in the middle of the first packaging box; springs are connected to both sides of the vibration reduction mechanism; the vibration reduction mechanism comprises a mass block and a second packaging box, the mass block is arranged in the second packaging box, and the second packaging box and the mass block are slidably connected; magnet assemblies are connected to both sides of the mass block; the magnet assembly is connected to the third magnet through a spring, and the magnet assembly and the third magnet repel each other, when the blade vibrates, the mass block drives the magnet assembly to reciprocate along the second packaging box and generates current for blade vibration reduction; during the vibration of the blade, according to Lenz's law, it can be known that the mass block absorbs the kinetic energy of the blade and moves left and right along the second packaging box, resulting in a continuous change of the magnetic flux in the second packaging box, generating an Ampere force that is always opposite to the movement direction of the mass block, preventing the displacement of the mass block and generating current, accelerating the energy dissipation of the blade, and playing a role of a damping force, thereby further improving the vibration reduction efficiency of the blade and reducing the damage and breakage of the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a diagram showing the connection relationship between the vibration reduction mechanism and the blades provided in an embodiment of the present invention;

[0019] Figure 2 1 is a schematic structural diagram of a vibration reduction device for a wind turbine blade provided by an embodiment of the present invention;

[0020] Figure 31 is a schematic structural diagram of a vibration reduction device for a wind turbine blade provided by an embodiment of the present invention;

[0021] Figure 4 is a schematic diagram of the structure of a vibration reduction mechanism provided by an embodiment of the present invention;

[0022] Figure 5 It is a schematic diagram of the magnetic field of the vibration reduction mechanism provided by the present invention;

[0023] In the figure: 1-blade; 2-first packaging box; 3-vibration reduction mechanism; 31-second packaging box; 32-mass block; 33-first magnet; 34-connecting rod; 35-second magnet; 36-locking cap; 4-third magnet; 5-spring; 6-temperature sensor. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0028] Example 1

[0029] In a first aspect, an embodiment of the present invention provides a vibration reduction device for a blade of a wind turbine generator, such as Figures 1 to 3As shown, a vibration reduction device for a wind turbine blade comprises a first packaging box 2, wherein the first packaging box 2 is arranged on a blade 1 of the wind turbine, third magnets 4 are arranged at both ends of the first packaging box 2, the first packaging box 2 is cylindrical, a vibration reduction mechanism 3 is arranged in the middle of the first packaging box 2, springs 5 ​​are connected to both sides of the vibration reduction mechanism 3, and the vibration reduction mechanism 3 is connected to the third magnet 4 through the spring 5.

[0030] like Figure 4 As shown, the vibration reduction mechanism 3 includes a mass block 32 and a second packaging box 31, the second packaging box 31 is arranged in the first packaging box 2, and magnet assemblies are connected to both sides of the mass block 32; the magnet assembly is connected to the third magnet 4 through a spring 5, and the magnet assembly and the third magnet 4 repel each other, one end of the spring 5 is connected to the lock cap 36, and the other end is connected to the third magnet 4; the magnet assembly includes a first magnet 33 and a second magnet 35; the first magnet 33 is connected to the mass block 32; the first magnet 33 is connected to the second magnet 35 through a connecting rod 34, the magnetic poles of the first magnet 33 and the second magnet 35 repel each other and can generate magnetic flux lines perpendicular to the connecting rod 34; the second magnet 35 is connected to the third magnet 4 through the spring 5, and the second magnet 35 and the third magnet 4 repel each other.

[0031] In this embodiment, the second packaging box 31 is set as a copper tube, because the copper tube has excellent electrical and thermal conductivity. The energy dissipated by the mass block 32 during the movement along the second packaging box 31 is converted into eddy currents generated along the inner wall of the second packaging box 31. The eddy currents operate in the loop and dissipate heat. When the blade 1 operates in severe cold weather, the heat generated by the second packaging box 31 is used to remove melted snow on the blade 1. A temperature sensor 6 is installed on the outer wall of the second packaging box 31, and the temperature sensor 6 is used to monitor the temperature of the second packaging box 31.

[0032] The spring 5 is an SMA spring, and its material is shape memory alloy. The natural frequency of the vibration damping device is proportional to the square root of the stiffness of the spring 5. Heating devices are connected to both ends of the spring 5; the temperature sensor is connected to the input end of the controller; the heating device is connected to the output end of the controller; therefore, when the blade 1 is in a situation of severe vibration, the controller can receive the data transmitted by the temperature sensor 6, and calculate the stiffness of the spring 5 corresponding to the best vibration absorption effect according to the real-time load conditions, and then adjust the ambient temperature of the shape memory alloy spring 5 through the heating devices at both ends of the spring 5, and then adjust the stiffness of the spring 5, so that the vibration absorption effect is optimized.

[0033] The mass block 32 is a high-density alloy, which can carry greater kinetic energy and provide a larger transfer platform, and can absorb more energy for the blade 1. When the blade 1 vibrates, the mass block 32 drives the first magnet 33 to reciprocate along the second packaging box 31, and can achieve a change in magnetic flux to generate an Ampere force. The Ampere force prevents the mass block 32 from displacing and generates current, which can accelerate the energy dissipation of the blade 1 and play a role of a damping force. Due to the effect of the Ampere force, the vibration absorption device can also achieve excellent vibration control effect when the frequency is inconsistent with the load frequency, thereby further improving the vibration reduction efficiency of the blade 1 and reducing the damage and breakage of the blade 1.

[0034] When the blade 1 vibrates, the mass block 32 drives the first magnet 33 to reciprocate along the second packaging box 31, and converts the kinetic energy generated by the movement of the blade 1 into electrical energy for vibration reduction of the blade 1; further, the magnet assembly includes a first magnet 33 and a second magnet 35; one side of the first magnet 33 is an N pole, and the other side is an S pole. In this embodiment, the left side of the first magnet 33 is an N pole, and the right side is an S pole. The first magnet 33 and the second magnet 35 attract each other by opposite poles to strengthen the connection with the mass block 32.

[0035] The first magnet 33 is connected to the mass block 32; the first magnet 33 is connected to the second magnet 35 through a connecting rod 34, the connecting rod 34 is made of high-density alloy, the magnetic poles of the first magnet 33 and the second magnet 35 repel each other to generate magnetic lines of force, and the magnetic lines of force are perpendicular to the connecting rod 34; the second magnet 35 is connected to the third magnet 4 through a spring 5, and the second magnet 35 and the third magnet 4 repel each other; a locking cap 36 is provided at the end of the second magnet 35, the locking cap 36 is made of high-density alloy, and the locking cap 36 is used to prevent the second magnet 35 from slipping, thereby fixing the magnetic pole distance to ensure the magnetic field strength.

[0036] like Figure 5 As shown, in the embodiment of the present invention, the vibration energy of the blade 1 is absorbed by the mass block 32, and then the vibration energy is converted into electrical energy and heat energy through the Ampere force generated by the magnetic field and dissipated. The mass block 31 continuously absorbs the converted energy to maintain dynamic balance; when the mass block 32 moves along the second packaging box 31, the movement direction is just perpendicular to the magnetic flux lines, and the mass block 32 repeatedly cuts the magnetic flux lines to generate the Ampere force in the opposite direction of the movement of the mass block 32. The Ampere force is used to prevent the displacement of the mass block 32 and generate current to reduce the vibration of the blade 1, which can greatly reduce the vibration amplitude of the blade 1 and reduce the vibration damage of the blade 1; the kinetic energy absorbed by the mass block 32 from the blade 1 will be converted into electrical energy in the second packaging box 31, and the electrical energy will eventually be converted into heat energy and dissipated. In this process, the mass block 32 will continuously absorb kinetic energy from the blade 1, and the cycle will be repeated to maintain the vibration amplitude of the blade 11 within a safe range.

[0037] A vibration reduction device for wind turbine blades: In the embodiment of the present invention, a mass block 32 is arranged in a second packaging box 31. When the blade 1 vibrates, the mass block 32 can carry a large amount of kinetic energy and reciprocate along the second packaging box 31. The two sides of the mass block 32 are connected with a first magnet 33. The two sides of the first magnet 33 are connected to the second magnet 35 through a connecting rod 34. The magnetic poles of the first magnet 33 and the second magnet 35 repel each other and generate axial magnetic flux lines. The mass block 32 drives the magnet assembly to reciprocate along the second packaging box 31 and generates current for vibration reduction of the blade 1. During the vibration of the blade 1, according to Lenz's law, it can be known that the mass block absorbs the kinetic energy of the blade 1 and moves left and right along the second packaging box, resulting in a continuous change of the magnetic flux in the second packaging box 31, generating an Ampere force that is always opposite to the movement direction of the mass block 32, preventing the mass block 32 from being displaced and generating current, accelerating the energy dissipation of the blade 1, and playing a role of a damping force. Due to the effect of the Ampere force, even when the frequency of the vibration absorbing device is inconsistent with the load frequency, an excellent vibration control effect can be achieved.

[0038] Example 2

[0039] In a second aspect, an embodiment of the present invention provides a wind turbine, comprising blades and the vibration reduction device described in Example 1; the vibration reduction device is installed on the blade 1; the vibration reduction device is perpendicular to the rotation plane of the blade 1.

[0040] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A vibration reduction device for a wind turbine blade, It is characterized in that The invention comprises a first packaging box (2), the first packaging box (2) being arranged on a blade (1) of a wind turbine, and third magnets (4) being arranged at both ends of the first packaging box (2); a vibration reduction mechanism (3) being arranged in the middle of the first packaging box (2); and springs (5) being connected to both sides of the vibration reduction mechanism (3); The vibration reduction mechanism (3) comprises a mass block (32) and a second packaging box (31); the mass block (32) is arranged in the second packaging box (31), and the second packaging box (31) and the mass block (32) are slidably connected; magnet assemblies are connected to both sides of the mass block (32); the magnet assembly and the third magnet (4) are connected via a spring (5), and the magnet assembly and the third magnet (4) repel each other; The magnet assembly comprises a first magnet (33) and a second magnet (35); the first magnet (33) is connected to the mass block (32); the first magnet (33) is connected to the second magnet (35) via a connecting rod (34); the magnetic poles of the first magnet (33) and the second magnet (35) repel each other and can generate magnetic flux lines perpendicular to the connecting rod (34); the second magnet (35) and the third magnet (4) are connected via a spring (5); the second magnet (35) and the third magnet (4) repel each other; The energy dissipated by the mass block (32) during movement along the second packaging box (31) is converted into eddy currents generated along the inner wall of the second packaging box (31); the eddy currents are converted into heat in a loop; and the heat generated by the second packaging box (31) is used to remove melted snow on the blades (1); The spring (5) is an SMA spring, and both ends of the spring (5) are connected to heating devices; a temperature sensor (6) is installed on the outer wall of the second packaging box (31); the temperature sensor (6) is connected to the input end of the controller, and the heating device is connected to the output end of the controller; The controller adjusts the ambient temperature of the spring (5) through the heating devices at both ends of the spring (5), thereby changing the stiffness of the spring (5) to adjust the vibration absorption effect.

2. A vibration reduction device for a wind turbine blade according to claim 1, It is characterized in that A locking cap (36) is provided at the end of the second magnet (35) for preventing the second magnet (35) from sliding off.

3. A vibration reduction device for a wind turbine blade according to claim 2, It is characterized in that One end of the spring (5) is connected to the lock cap (36), and the other end is connected to the third magnet (4).

4. A vibration reduction device for a wind turbine blade according to claim 2, It is characterized in that The connecting rod (34), the locking cap (36) and the mass block (32) are all made of high-density alloy.

5. A vibration reduction device for a wind turbine blade according to claim 1, It is characterized in that The second packaging box (31) is made of copper.

6. A wind turbine, comprising a blade and the vibration reduction device according to any one of claims 1 to 5, wherein the vibration reduction device is mounted on the blade (1), and the vibration reduction device is perpendicular to the rotation plane of the blade (1).

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