Electro-vortex non-tuned mass damper for wind turbine blades, wind turbine blade

Abstract

The application discloses an eddy current non-tuned mass damper for a wind power blade, and a wind power blade, and relates to the technical field of wind power blades. The eddy current non-tuned mass damper for the wind power blade comprises an eddy current motion damping structure part and an eddy current braking damping structure part, the eddy current motion damping structure part comprises a motion mass, a non-magnetic metal conductor and a permanent magnet, the motion mass is arranged in the non-magnetic metal conductor, and the permanent magnet is arranged on the motion mass; the eddy current braking damping structure part comprises a first braking permanent magnet, a second braking permanent magnet, a first eddy current plate and a second eddy current plate, the first braking permanent magnet is arranged at two ends of the motion mass, the second braking permanent magnet is arranged at two ends of the non-magnetic metal conductor, the first eddy current plate is arranged at the two ends of the motion mass and located at the inner side of the first braking permanent magnet, and the second eddy current plate is arranged at the two ends of the non-magnetic metal conductor and located at the outer side of the second braking permanent magnet. The eddy current non-tuned mass damper has the advantages of long service life, free mechanical maintenance and high-efficiency damping, and can effectively inhibit the first-order vibration of blade oscillation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind power generation, in particular to an eddy current non-tuned mass damper for a wind power blade and the wind power blade. BACKGROUND

[0002] The manufacturing technology of wind turbine generators is changing rapidly, and the single-machine capacity of the generators has broken through the 20MW level, the length of the blades has exceeded 100m, the hub height of the wind turbine has broken through 150m, and so on. The cost value of the generators is also increasing. In the face of complex wind resource conditions, the risk of blade damage is also increasing. For the wind turbine blade, it is a slender shell structure and very flexible. In the complex and variable strong wind environment, the vibration problem is very prominent, especially the first-order mode vibration in the pendulum direction. If it cannot be well damped and inhibited, it will have a serious impact on the fatigue life of the blade, and when resonance occurs, the disaster of broken blades will also occur.

[0003] In the prior art, the damping suppression mainly has the following several ways:

[0004] 1) Tuned mass damper, which is abbreviated as TMD, including liquid tuned mass damper, eddy current tuned mass damper and different types;

[0005] 2) Using viscoelastic matrix material;

[0006] 3) Cooperating with a control system to perform aerodynamic damping;

[0007] The above several damping suppression methods have some fatal defects when applied to wind power blades, which leads to difficulty in practical application.

[0008] As for the current damping suppression scheme using the eddy current tuned mass damper, the eddy current tuned mass damper includes four core components of a moving mass, a motion constraint, a tuned spring and an eddy current electromagnetic induction structure, and the basic working principle is as follows: the damper is installed on a vibrating body, when external disturbance excitation causes the vibrating body to vibrate, the moving mass is an inertial body, the kinetic energy of the vibrating body is coupled through the tuned spring, and the kinetic energy is transmitted to the moving mass, the moving mass is provided with a permanent magnet, the permanent magnet is provided with a stationary installed eddy current plate on a movement path of the permanent magnet, there is reciprocating motion between the permanent magnet and the eddy current plate and electromagnetic induction is generated, and then eddy current loss is generated, the kinetic energy of the vibrating body is absorbed, and the damping effect is achieved. This damping suppression scheme has been successfully applied in the fields of bridges, high-rise buildings, fan towers and the like, and is more effective for the suppression of second-order vibration, but is limited by the limitations and particularity of the blade structure, and there is no efficient and practical eddy current tuned mass damping scheme to prevent the first-order vibration of the blade, especially the first-order vibration damping in the blade oscillation direction. Since the blade rotates around the horizontal axis of the center shaft of the wind turbine at a certain speed, the damper rotates with the impeller to flip up and down, and in the flipping process, the reliability of the tuned spring inside the damper which plays a mass tuning role is greatly tested. The tuned spring increases the volume of the damper and offsets the damping force. In the face of impact force, centrifugal force and other fatigue loads of up to tens of millions of reciprocating movements, the tuned spring is difficult to meet the 20-25 year service requirement. In order to facilitate later maintenance, the damper must be installed at the central position of the blade inner cavity, i.e. at the 1 / 2 blade length position, and at this position, the damping effect will be greatly reduced, the moving mass will be very large, and the number will be large, which will affect the blade strength and other side effects. SUMMARY

[0009] The first object of the present application is to overcome the shortcomings and deficiencies of the prior art, and to provide an eddy current non-tuned mass damper for a wind power blade, which cancels the tuned spring, prolongs the service life, realizes mechanical maintenance-free of the damper during the service life, realizes magnetic force buffering and high-efficiency damping by introducing a magnetic force eddy current braking mechanism and combining with a track constraint, and in the track constraint mechanism, a frictionless magnetic suspension type linear motion constraint mechanism is proposed, which integrates the magnetic suspension and eddy current damping effects, significantly improves the service life of the damper under the premise of high-efficiency damping, and can effectively suppress the first-order vibration of the blade oscillation.

[0010] The second object of the present application is to provide a wind power blade.

[0011] The first object of the present application can be achieved by adopting the following technical scheme:

[0012] The application discloses an eddy current non-tuned mass damper for a wind power blade, which comprises an eddy current motion damping structure part and an eddy current braking damping structure part; the eddy current motion damping structure part comprises a motion mass, a non-magnetic metal conductor and a permanent magnet, the non-magnetic metal conductor is in a hollow structure, the motion mass is installed in the hollow interior of the non-magnetic metal conductor and can perform left-right linear reciprocating motion in the non-magnetic metal conductor, and the permanent magnet is installed on the outer wall of the motion mass and can synchronously move with the motion mass and relatively move with the non-magnetic metal conductor, so that the eddy current motion damping is generated between the permanent magnet and the non-magnetic metal conductor to dissipate the first-order vibration energy of blade oscillation; the eddy current braking damping structure part comprises a first braking permanent magnet, a second braking permanent magnet, a first eddy current plate and a second eddy current plate, the first braking permanent magnet has two pieces and is arranged at two ends of the motion mass respectively, the second braking permanent magnet has two pieces and is arranged at two ends of the non-magnetic metal conductor respectively, the magnetic pole polarity of the first braking permanent magnet and the second braking permanent magnet is opposite, the first braking permanent magnet and the second braking permanent magnet with opposite magnetic pole polarity are used to slow down and brake the motion mass, so that rigid collision of the motion mass with the two ends of the non-magnetic metal conductor is avoided, the first eddy current plate has two pieces and is arranged at the two ends of the motion mass and located at the inner side of the first braking permanent magnet, the second eddy current plate has two pieces and is arranged at the two ends of the non-magnetic metal conductor and located at the outer side of the second braking permanent magnet, the motion mass is slowed down when reciprocating to the left and right two ends, and the eddy current braking damping is generated between the first eddy current plate, the second eddy current plate and the permanent magnet to dissipate the first-order vibration energy of blade oscillation.

[0013] Further, the non-magnetic metal conductor is in a circular ring shape in cross section, the motion mass is in a plunger shape and is provided with a through hole penetrating through two ends at the center, the non-magnetic metal conductor forms a sliding friction type linear motion constraint on the motion mass, the permanent magnet comprises a plurality of magnetic rings which are connected in series and are arranged on the outer wall of the motion mass along the axial direction of the motion mass, the plurality of magnetic rings are driven by the motion mass to relatively move with the non-magnetic metal conductor, and the eddy current motion damping is generated between the magnetic rings and the non-magnetic metal conductor.

[0014] Further, the non-magnetic metal conductor is in a rectangular shape in cross section and is provided with a ball type linear guide rail, the ball type linear guide rail comprises a slide rail and a slide block, the slide rail is installed on the inner bottom surface of the non-magnetic metal conductor, the slide block is installed on the bottom surface of the motion mass, the ball type linear guide rail forms a rolling friction type linear motion constraint on the motion mass, the permanent magnet comprises a plurality of magnetic blocks or magnetic sheets which are distributed on the outer wall of the motion mass, the motion mass can move along the slide rail following the slide block, the magnetic blocks or magnetic sheets on the motion mass relatively move with the non-magnetic metal conductor, and the eddy current motion damping is generated.

[0015] Further, the left and right ends of the moving mass are respectively uniformly distributed with a plurality of rolling bearings, the inner ring of each rolling bearing is connected with the moving mass, and the outer ring is in contact with the inner wall of the non-magnetic metal conductor and rolls relative to each other, and the moving mass is constrained by the rolling bearings and the non-magnetic metal conductor to form a non-slip friction linear motion.

[0016] Further, the first braking permanent magnet and the second braking permanent magnet are both button type strong magnetic sheets.

[0017] An eddy current non-tuned mass damper for a wind turbine blade, comprising an eddy current motion damping structure part and an eddy current braking damping structure part; the eddy current motion damping structure part comprises a moving mass, a non-magnetic metal conductor and a permanent magnet, the non-magnetic metal conductor is in a hollow structure, the moving mass is made of a non-magnetic metal material, is installed in the hollow interior of the non-magnetic metal conductor, and can perform left-right linear reciprocating motion in the non-magnetic metal conductor, the permanent magnet comprises a first permanent magnet arranged on the moving mass and a second permanent magnet arranged on the non-magnetic metal conductor, and the magnetic poles of the first permanent magnet and the second permanent magnet are opposite to each other to generate repulsive magnetic force, the moving mass is constrained by the first permanent magnet and the second permanent magnet to form a magnetic levitation linear motion, and the first permanent magnet can move synchronously with the moving mass and relatively move with the non-magnetic metal conductor, thereby generating eddy current motion damping between the two to dissipate the first-order vibration energy of blade flap vibration, and the moving mass relatively moves with the second permanent magnet and generates eddy current motion damping between the two to dissipate the first-order vibration energy of blade flap vibration; the eddy current braking damping structure part comprises a first braking permanent magnet, a second braking permanent magnet, a first eddy current plate and a second eddy current plate, the first braking permanent magnet has two pieces arranged at the two ends of the moving mass, the second braking permanent magnet has two pieces arranged at the two ends of the non-magnetic metal conductor, the magnetic poles of the first braking permanent magnet and the second braking permanent magnet are opposite, the first braking permanent magnet and the second braking permanent magnet with opposite magnetic poles are used to slow down and brake the moving mass, thereby avoiding rigid collision of the moving mass with the two ends of the non-magnetic metal conductor, the first eddy current plate has two pieces arranged at the two ends of the moving mass and located on the inner side of the first braking permanent magnet, and the second eddy current plate has two pieces arranged at the two ends of the non-magnetic metal conductor and located on the outer side of the second braking permanent magnet, the moving mass slows down when reciprocating to the left and right ends, and generates eddy current braking damping between the first eddy current plate, the second eddy current plate and the permanent magnet to dissipate the first-order vibration energy of blade flap vibration.

[0018] Further, the non-magnetic metal conductor has a rectangular cross section, the moving mass has a rectangular cross section and is provided with a through hole at the center, the first and second permanent magnets are both button-shaped magnetic sheets, the first permanent magnets are arranged on two opposite edges of the moving mass which are parallel to the moving direction of the moving mass, and the second permanent magnets are arranged on two opposite edges inside the non-magnetic metal conductor which are parallel to the moving direction of the moving mass and correspond to the two opposite edges of the moving mass.

[0019] Further, the first and second braking permanent magnets are both button-shaped strong magnetic sheets.

[0020] The second object of the present application can be achieved by adopting the following technical scheme:

[0021] A wind power blade, the blade has the above-mentioned eddy current non-tuned mass damper for wind power blades, the damper is installed inside the blade at a position at least 2 / 3 of the blade length away from the blade root, the moving axis of the damper is consistent with the blade oscillation direction, and the blade skin is provided with a lightning arrester at a position corresponding to the damper.

[0022] Further, the damper has at least two, one of which has a moving axis consistent with the blade oscillation direction, and the other has a moving axis consistent with the blade flapping direction.

[0023] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0024] 1. The damper of the present application has simple structure and reliable performance, cancels the tuning spring, prolongs the service life, realizes mechanical maintenance-free during the service life of the damper, introduces a magnetic eddy current braking mechanism, combines with track constraint, realizes magnetic buffering and high-efficiency damping, and in the track constraint mechanism, proposes a frictionless magnetic levitation type linear motion constraint mechanism that integrates magnetic levitation and eddy current damping effects, which significantly improves the service life of the damper under the premise of high-efficiency damping.

[0025] 2. The damper of the present application is mechanical maintenance-free, so it can be arranged inside the blade and placed as close to the blade tip as possible, which can effectively suppress the first-order vibration of the blade and realize high-efficiency damping. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structural schematic view of the eddy current non-tuned mass damper of Example 1.

[0027] Figure 2 It is a structural schematic view of the eddy current non-tuned mass damper of Example 1. Figure 1 It is a sectional view in the direction of A-A.

[0028] Figure 3A structural schematic diagram of the eddy current non-tuned mass damper of Example 1.

[0029] Figure 4 A structural schematic diagram of the eddy current non-tuned mass damper of Example 2. Figure 3 A cross-sectional view along B-B.

[0030] Figure 5 A structural schematic diagram of the eddy current non-tuned mass damper of Example 4.

[0031] Figure 6 A structural schematic diagram of the eddy current non-tuned mass damper of Example 2. Figure 5 A cross-sectional view along C-C.

[0032] Figure 7 A structural schematic diagram of the eddy current non-tuned mass damper of Example 2. Figure 5 A cross-sectional view along D-D.

[0033] Figure 8 A structural schematic diagram of the rotary eddy current non-tuned mass damper of Example 5.

[0034] Figure 9 A structural schematic diagram of the wind turbine blade of Example 6. DETAILED DESCRIPTION

[0035] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0036] Example 1:

[0037] As shown in the figure, the present embodiment provides an eddy current non-tuned mass damper for a wind turbine blade, which comprises an eddy current motion damping structure part and an eddy current braking damping structure part. Figures 1-2 The eddy current motion damping structure part comprises a motion mass 101, a non-magnetic metal conductor 102 and a permanent magnet 103. The non-magnetic metal conductor 102 has a hollow structure and functions as a damper shell. The motion mass 101 is installed in the hollow interior of the non-magnetic metal conductor 102 and can perform left-right linear reciprocating motion in the non-magnetic metal conductor 102. The permanent magnet 103 is installed on the outer wall of the motion mass 101 and can move synchronously with the motion mass and relative to the non-magnetic metal conductor, thereby generating eddy current motion damping between the permanent magnet and the non-magnetic metal conductor to dissipate the first-order vibration energy of blade oscillation.

[0038]

[0039] ​The eddy current brake damping structure part comprises a first brake permanent magnet 104, a second brake permanent magnet 105, a first eddy current plate 106 and a second eddy current plate 107, the first brake permanent magnet 104 is provided at two ends of the moving mass 101, the second brake permanent magnet 105 is provided at two ends of the non-magnetic metal conductor 102, the magnetic pole polarity of the first brake permanent magnet 104 and the second brake permanent magnet 105 is opposite, the moving mass 101 is decelerated and braked by the first brake permanent magnet 104 and the second brake permanent magnet 105 with opposite magnetic pole polarity, so as to avoid rigid collision with the two ends of the non-magnetic metal conductor 102, the first eddy current plate 106 is provided at two ends of the moving mass 101 and located at the inner side of the first brake permanent magnet 104, the second eddy current plate 107 is provided at two ends of the non-magnetic metal conductor 102 and located at the outer side of the second brake permanent magnet 105, the moving mass is decelerated when moving to the left and right ends, and the first eddy current plate and the second eddy current plate generate eddy current brake damping between the moving mass and the non-magnetic metal conductor, so as to dissipate the first-order vibration energy of the blade swing.

[0040] Specifically, the cross section of the non-magnetic metal conductor 102 is circular ring, preferably 304 stainless steel pipe, which has the functions of the eddy current plate and the sealed shell, the moving mass 101 is in the shape of a plunger, and a through hole 1011 is arranged at the center of the moving mass 101 and penetrates two ends, so that the air pressure of the space at two ends of the moving mass 101 is balanced, and there is a moderate gap between the moving mass 101 and the non-magnetic metal conductor 102, so that the moving mass 101 is constrained to slide and move linearly by the non-magnetic metal conductor 102, the permanent magnet 103 comprises a plurality of magnetic rings connected in series, and the plurality of magnetic rings connected in series are arranged on the outer wall of the moving mass 101 in the axial direction of the moving mass 101, so that the plurality of magnetic rings are driven by the moving mass 101 to move relative to the non-magnetic metal conductor 102, and then the eddy current motion damping is generated between the magnetic rings and the non-magnetic metal conductor 102.

[0041] Specifically, the first brake permanent magnet 104 and the second brake permanent magnet 105 are both in the shape of a button type strong magnetic sheet.

[0042] The damper of the embodiment relies on the circular pipe geometry of the non-magnetic metal conductor to constrain the moving mass to move linearly in the axial direction, the non-magnetic metal conductor has the attribute of the eddy current plate, the permanent magnet is arranged on the moving mass, so that the eddy current damping is generated while the moving mass moves, and there is sliding friction between the non-magnetic metal conductor and the moving mass, the friction is also a damping mode, which can work in a superimposed manner with the eddy current damping, the structure is simple and practical, and the reliability is high, and the wear life can be improved by lubrication.

[0043] The vibration natural frequency of the blade is basically below 1 Hz. Since the blade has a length of hundreds of meters, the amplitude of the blade tip reaches several meters when the blade vibrates, which belongs to the low-frequency and large-amplitude type. The internal space of the blade is very narrow, and the chord length of the internal chord space (from the middle of the blade to the tip section) is only meters, and the thickness size is less than half a meter. The embodiment is aimed at such narrow actual space constraints. By removing the tuning spring, the service life of the damper is prolonged, the volume is greatly reduced, the space is saved, and the narrow installation space can be adapted. At the same time, the tuning spring in the prior art has a side effect on the damping mechanism while playing a tuning role. The damper of the embodiment works in a non-tuned state, and the damper will respond to a movement return to absorb vibration energy for each swing vibration of the blade. That is, when the external wind excitation is not at the resonance frequency, the damper of the embodiment can play a vibration suppression role. At the blade resonance frequency, the damping effect will not be weakened.

[0044] The specific working principle of the damper of the embodiment is as follows: the damper is installed on the vibrating body (i.e., the blade). When external disturbance excitation causes the vibrating body to vibrate (the disturbance excitation is equivalent to the wind excitation of the blade), the moving mass is an inertial body, and the permanent magnet thereon moves relative to the non-magnetic metal conductor to generate electromagnetic induction and electromagnetic force. The electromagnetic force is the damping force and the driving force for driving the moving mass to move left and right in the non-magnetic metal conductor. The eddy current loss will absorb the kinetic energy of the vibrating body to play a damping role. At the same time, during the swing vibration of the moving mass, the electromagnetic force f in the forward stroke drives the moving mass to displace s from a position, and does work fs. In the return stroke, the electromagnetic force f in the return stroke drives the moving mass to displace s from the end position in the opposite direction, and does work fs. Through the reciprocating motion of the moving mass, the kinetic energy is converted into electromagnetic energy and is lost. Compared with the existing tuned damper, the electromagnetic force design of the damper of the embodiment can be greatly improved, the work efficiency is greatly improved, and the damping effect is greatly improved.

[0045] The damper absorbs a portion of the kinetic energy in each movement return. Under the condition of the magnetic flux of the magnetic field and the resistivity of the eddy current plate, the size of the absorbed energy is related to the movement speed of the moving mass. Through the high-speed movement of the moving mass in the non-magnetic metal conductor for more than 90% of the stroke (the remaining stroke is the braking distance), the faster the speed, the higher the induced voltage, the greater the eddy current, the greater the electromagnetic force, and the greater the electric power. Compared with the damping performance of the damper with a tuning spring, the damping performance is significantly improved.

[0046] In addition, the non-magnetic metal conductor can also be optimized into a composite tube. The composite tube can be made of high-conductivity materials such as copper and aluminum as the material for inducing eddy current, and the sliding friction surface is preferably made of high-wear-resistant materials such as ceramic high-hardness materials or polytetrafluoroethylene self-lubricating wear-resistant materials.

[0047] Embodiment 2:

[0048] As shown in Figures 3-4 The embodiment provides an eddy current non-tuned mass damper for a wind power blade, and the damper of the embodiment is different from that of Embodiment 1 in that rolling friction is used instead of sliding friction for the moving mass, and the specific structure is that a non-magnetic metal conductor 202 with a rectangular cross section is used, and a ball linear guide is further arranged in the non-magnetic metal conductor 202, the ball linear guide includes a slide rail 208 and a slide block 209, the slide rail 208 is mounted on the inner bottom surface of the non-magnetic metal conductor 202, the slide block 209 is mounted on the bottom surface of the moving mass, the ball linear guide forms rolling friction type linear motion constraint for the moving mass, the permanent magnet includes a plurality of magnetic blocks or magnetic sheets, the plurality of magnetic blocks or magnetic sheets are distributed on the outer wall of the moving mass, the moving mass can move along the slide block 209 along the slide rail 208, thereby driving the magnetic blocks or magnetic sheets on the moving mass to move relative to the non-magnetic metal conductor 202, and generating eddy current motion damping.

[0049] The damper of the embodiment uses the constraint structure of the ball linear guide, so that the moving mass can bear a larger lateral load, greatly improving the reliability of the damper and prolonging the service life.

[0050] Embodiment 3:

[0051] The embodiment provides an eddy current non-tuned mass damper for a wind power blade, and the damper of the embodiment is different from that of Embodiment 1 in that a plurality of rolling bearings are uniformly distributed on the left and right ends of the moving mass along the circumferential direction, such as 4 or 3 rolling bearings are uniformly distributed on each end along the circumferential direction, so that the centering stabilizing frame of the moving mass is stably suspended on the center line of the non-magnetic metal conductor, the inner ring of each rolling bearing is connected with the moving mass, and the outer ring is in contact with the inner wall of the non-magnetic metal conductor and relatively rolls, the rolling bearing forms a non-sliding friction type linear motion constraint for the moving mass, greatly reduces the motion friction, and improves the service life of the damper.

[0052] Embodiment 4:

[0053] As shown in Figures 5-7 The embodiment provides an eddy current non-tuned mass damper for a wind power blade, and the damper of the embodiment is different from that of Embodiment 1 in that rolling friction is used instead of sliding friction for the moving mass, and the specific structure is that a non-magnetic metal conductor 202 with a rectangular cross section is used, and a ball linear guide is further arranged in the non-magnetic metal conductor 202, the ball linear guide includes a slide rail 208 and a slide block 209, the slide rail 208 is mounted on the inner bottom surface of the non-magnetic metal conductor 202, the slide block 209 is mounted on the bottom surface of the moving mass, the ball linear guide forms rolling friction type linear motion constraint for the moving mass, the permanent magnet includes a plurality of magnetic blocks or magnetic sheets, the plurality of magnetic blocks or magnetic sheets are distributed on the outer wall of the moving mass, the moving mass can move along the slide block 209 along the slide rail 208, thereby driving the magnetic blocks or magnetic sheets on the moving mass to move relative to the non-magnetic metal conductor 202, and generating eddy current motion damping.

[0054] The eddy current motion damping structure part comprises a motion mass 401, a non-magnetic metal conductor 402 and a permanent magnet, the non-magnetic metal conductor 402 is in a hollow structure, the motion mass 401 is made of a non-magnetic metal material, is installed in the hollow interior of the non-magnetic metal conductor 402 and can perform left-right linear reciprocating motion in the non-magnetic metal conductor 402, the permanent magnet comprises a first permanent magnet 4031 arranged on the motion mass 401 and a second permanent magnet 4032 arranged on the non-magnetic metal conductor 402, and the magnetic poles of the first permanent magnet 4031 and the second permanent magnet 4032 are opposite to generate mutual repulsion magnetic force, the first permanent magnet and the second permanent magnet form a magnetic suspension type linear motion constraint for the motion mass, and the first permanent magnet can move synchronously with the motion mass and relatively move with the non-magnetic metal conductor, so as to generate eddy current motion damping between the two to dissipate the first-order vibration energy of the blade oscillation, and the motion mass relatively moves with the second permanent magnet and generates eddy current motion damping between the two to dissipate the first-order vibration energy of the blade oscillation.

[0055] The eddy current brake damping structure part comprises a first brake permanent magnet 104, a second brake permanent magnet 105, a first eddy current plate 106 and a second eddy current plate 107, the first brake permanent magnet 104 has two pieces arranged at two ends of the motion mass 401, the second brake permanent magnet 105 has two pieces arranged at two ends of the non-magnetic metal conductor 402, the magnetic poles of the first brake permanent magnet 104 and the second brake permanent magnet 105 are opposite, the first brake permanent magnet 104 and the second brake permanent magnet 105 with opposite magnetic poles are used to slow down and brake the motion mass 401, thereby avoiding rigid collision of the motion mass 401 with the two ends of the non-magnetic metal conductor 402, the first eddy current plate 106 has two pieces arranged at the two ends of the motion mass 401 and located on the inner side of the first brake permanent magnet 104, the second eddy current plate 107 has two pieces arranged at the two ends of the non-magnetic metal conductor 402 and located on the outer side of the second brake permanent magnet 105, the motion mass slows down when reciprocating to the left and right two ends, and the first eddy current plate and the second eddy current plate generate eddy current brake damping with the permanent magnet to dissipate the first-order vibration energy of the blade oscillation.

[0056] The cross section of the non-magnetic metal conductor 402 is rectangular, the cross section of the moving mass 401 is rectangular, and a through hole 4011 is arranged at the center of the moving mass 401 and penetrates two ends; the non-magnetic metal conductor 402 and the moving mass 401 are in clearance fit; the first permanent magnet 4031 and the second permanent magnet 4032 are both button-shaped magnetic sheets; a group of opposite edges of the moving mass 401 and the non-magnetic metal conductor 402 are selected respectively, the two groups of opposite edges correspond to each other respectively and are parallel to the moving direction of the moving mass 401; the first permanent magnet 4031 is arranged on two opposite edges of the moving mass 401, and the second permanent magnet 4032 is arranged on two opposite edges inside the non-magnetic metal conductor 402; the magnetic pole polarity of the first permanent magnet 4031 and the second permanent magnet 4032 is opposite, so that the magnets on the edges of the non-magnetic metal conductor 402 and the magnets on the edges of the moving mass 401 generate magnetic repulsion, and the first permanent magnet 4031 and the second permanent magnet 4032 form a magnetic suspension type linear motion constraint for the moving mass 401.

[0057] Specifically, the first brake permanent magnet 104 and the second brake permanent magnet 105 are both button-shaped strong magnetic sheets.

[0058] The damper of the embodiment adopts a four-surface magnetic suspension constraint mechanism in orthogonal directions, a Cartesian coordinate system OXYZ is introduced, the X direction is the moving degree of freedom direction, and the YZ direction is the displacement constraint direction, that is, the permanent magnet magnetic suspension technology is applied in the Y direction and the Z direction, the non-contact between the moving mass and the moving track is obtained, the force balance of the moving mass in the magnetic suspension state along the Y direction and the Z direction and the torque balance around the X axis are realized, the friction is eliminated by using the magnetic suspension, the reliability of the damper is greatly improved, the service life is prolonged, and the damper is truly permanently maintenance-free.

[0059] The magnetic suspension linear motion constraint formed by the first permanent magnet and the second permanent magnet on the moving mass in the embodiment is a one-dimensional constraint, and can also be extended to a two-dimensional constraint according to actual conditions. For example, a Cartesian coordinate system OUW is introduced, the U direction is the motion displacement constraint direction, and the VW direction is the motion degree of freedom direction, that is, the permanent magnet magnetic suspension technology is applied in the U direction to obtain the non-contact between the moving mass and the motion plane. This motion trajectory constraint structure satisfies the motion damping of the damper in the plane, for example, the three vibration dampings of the blade, i.e., the pendulum vibration, the waving vibration and the torsion vibration. The specific implementation structure is as follows: a pie-shaped metal box is selected to serve as an eddy current plate, there is a chess-like cylindrical moving mass in the metal box, the end plane of the cylindrical moving mass is parallel to the pie plane of the pie-shaped metal box, a small motion gap is left, the inner surface of the pie-shaped metal box and the outer surface of the cylindrical moving mass are densely covered with permanent magnets, the opposite setting of the magnets with opposite polarities is ensured, and the magnets on the pie-shaped metal box and the magnets on the moving mass generate magnetic repulsion, so that the moving mass in the magnetic suspension state can realize the motion degree of freedom along the VW plane.

[0060] The remanence of the permanent magnet in the damper, the distance between the permanent magnet and the eddy current plate, the material of the eddy current plate and the relative motion speed all affect the size of the electromagnetic induction force. Generally, copper material is selected for the eddy current plate serving as the moving mass, aluminum material is selected for the static eddy current plate (i.e., the non-magnetic metal conductor), and the composite structure can also be designed according to the needs. In the embodiment, the moving mass and the non-magnetic metal conductor have opposite permanent magnets and eddy current plates, which can double electromagnetic induction power generation, and the structural efficiency is very high. Similarly, at the braking end of the reciprocating motion, two braking permanent magnets are arranged on two components in relative motion, i.e., the end of the moving mass and the end of the non-magnetic metal conductor. When the two components approach each other, the repulsive magnetic force slows down and brakes the moving mass. At the same time, the non-magnetic metal conductor is provided with eddy current plates at both ends, at this time, the magnetic flux passing through the eddy current plates changes, electromagnetic induction eddy current is generated, and then the kinetic energy is absorbed. This process is also double electromagnetic induction power generation.

[0061] Embodiment 5:

[0062] For example, Figure 8As shown, this embodiment provides a rotary eddy current untuned mass damper for wind turbine blades, including an eddy current ring 501, a rotor 502, and a lever arm 503. The eddy current ring 501 acts as an inertial body and has a large diameter. The rotor 502 is fitted inside the eddy current ring 501, and a ring of permanent magnet teeth 504 with a small tooth pitch is formed on its outer circumference. The lever arm 503 is connected to the end of the rotor 502. External torsional vibration is transmitted to the rotor 502 through the lever arm 503. The rotor 502 and the eddy current ring 501 rotate relative to each other, thereby driving the permanent magnet teeth 504 and the eddy current ring 501 to rotate relative to each other. When the two move, cutting magnetic lines of force or changing magnetic flux will generate eddy current loss work. The damper absorbs a portion of kinetic energy in each forward and reverse rotation return stroke.

[0063] Example 6:

[0064] like Figure 9 As shown, this embodiment provides a wind turbine blade, on which at least one damper 1 is installed. The damper 1 can be any one of the following: the damper with sliding friction linear motion constraint described in Embodiment 1, the damper with rolling friction linear motion constraint described in Embodiment 2, the damper with non-sliding friction linear motion constraint described in Embodiment 3, or the damper with magnetic levitation linear motion constraint described in Embodiment 4. The motion axis of the damper 1 is consistent with the blade oscillation direction, and a lightning arrester flashover point 2 is provided on the outer skin of the blade at a position corresponding to the damper.

[0065] Furthermore, in this embodiment, a damper 1 can be arranged in the blade flapping direction. Similarly, the damper 1 can be any one of the dampers in Embodiments 1 to 4. The damper is installed inside the blade at a position at least 2 / 3 of the blade length away from the blade root, and the movement axis of the damper 1 is aligned with the blade flapping direction.

[0066] For each blade's oscillating vibration, the damper can achieve vibration attenuation through eddy current loss without needing resonance. Each damper experiences two eddy current motion damping energy losses and two eddy current braking damping energy losses during one motion return stroke.

[0067] The blade is in a cantilevered state on the impeller, the mass and stiffness are concentrated in the direction of the blade root, the blade tip becomes light and flexible, the distribution of the transverse vibration amplitude on the length of the blade is not linear, and the vibration amplitude is enlarged in the form of a parabola, the amplitude is larger at the blade tip, the large amplitude means large kinetic energy, therefore, the damper is placed as close to the blade tip as possible, and is located at a position at a distance of at least 2 / 3 of the length of the blade from the blade root, so that efficient damping of the blade vibration can be achieved. Meanwhile, the damper is installed at the blade tip section, the vibration energy of the middle section of the blade is transmitted to the blade tip section through the blade body, which is equivalent to that the small-amplitude kinetic energy in the middle of the blade is transferred to the large-amplitude blade tip section, the kinetic energy is absorbed by the eddy current non-tuned mass damper, and the blade vibration is suppressed.

[0068] Further, the damper 3 arranged in the torsion direction of the blade can also be arranged in the embodiment, the damper 3 is a rotary eddy current non-tuned mass damper as described in the embodiment 5, the damper 3 and the damper 1 can be installed at staggered positions in the spanwise length direction of the blade, and the overall vibration reduction effect of the blade is improved by the dampers installed in three different directions.

[0069] The damper of the application cancels the tuned spring, greatly reduces the volume, prolongs the service life, realizes mechanical maintenance-free of the damper during the service life, realizes magnetic buffering and efficient damping by introducing the braking mechanism and combining the track constraint, and has important significance for solving the vibration failure of the blade and improving the fatigue life of the blade, and can produce significant economic benefits.

[0070] The above is only the preferred embodiment of the application, but the protection scope of the application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the application within the scope disclosed by the application, and the application still belongs to the protection scope of the application.

Claims

1. An eddy current non-tuned mass damper for a wind turbine blade, characterized by: The application relates to a kind of damping structures of electric eddy current motion and electric eddy current brake, which comprises an electric eddy current motion damping structure part and an electric eddy current brake damping structure part.The electric eddy current motion damping structure part comprises a moving mass, a non-magnetic metal conductor and a permanent magnet, the non-magnetic metal conductor is in a hollow structure, the moving mass is installed in the hollow interior of the non-magnetic metal conductor and can move linearly left and right within the non-magnetic metal conductor, and the permanent magnet is installed on the outer wall of the moving mass and can move synchronously with the moving mass and relative to the non-magnetic metal conductor, thereby generating electric eddy current motion damping between the permanent magnet and the non-magnetic metal conductor to dissipate the first-order vibration energy of blade oscillation.The electric eddy current brake damping structure part comprises a first brake permanent magnet, a second brake permanent magnet, a first electric eddy current plate and a second electric eddy current plate, the first brake permanent magnet has two pieces and is arranged at the two ends of the moving mass, the second brake permanent magnet has two pieces and is arranged at the two ends of the non-magnetic metal conductor, the magnetic poles of the first brake permanent magnet and the second brake permanent magnet are opposite, the first brake permanent magnet and the second brake permanent magnet with opposite magnetic poles are used to slow down and brake the moving mass, thereby avoiding rigid collision between the moving mass and the two ends of the non-magnetic metal conductor, the first electric eddy current plate has two pieces and is arranged at the two ends of the moving mass and on the inner side of the first brake permanent magnet, and the second electric eddy current plate has two pieces and is arranged at the two ends of the non-magnetic metal conductor and on the outer side of the second brake permanent magnet, the moving mass slows down when moving to the left and right ends, and generates electric eddy current brake damping between the first electric eddy current plate, the second electric eddy current plate and the permanent magnet to dissipate the first-order vibration energy of blade oscillation.

2. An eddy current non-tuned mass damper for a wind turbine blade according to claim 1, characterised in that: The cross section of the non-magnetic metal conductor is in a circular ring shape, the moving mass is in a plunger shape and has a through hole at the center for ventilation, the non-magnetic metal conductor forms a sliding friction type linear motion constraint on the moving mass, the permanent magnet comprises a plurality of magnetic rings connected in series, the plurality of magnetic rings connected in series are arranged on the outer wall of the moving mass in the axial direction and are driven by the moving mass to move relative to the non-magnetic metal conductor, thereby generating electric eddy current motion damping between the magnetic rings and the non-magnetic metal conductor.

3. An eddy current non-tuned mass damper for a wind turbine blade according to claim 1, characterised in that: The cross section of the non-magnetic metal conductor is in a rectangular shape and has a ball linear guide rail inside, the ball linear guide rail comprises a slide rail and a slide block, the slide rail is installed on the inner bottom surface of the non-magnetic metal conductor, the slide block is installed on the bottom surface of the moving mass, the ball linear guide rail forms a rolling friction type linear motion constraint on the moving mass, the permanent magnet comprises a plurality of magnetic blocks or magnetic sheets, the plurality of magnetic blocks or magnetic sheets are distributed on the outer wall of the moving mass, the moving mass can move along the slide rail with the slide block, thereby making the magnetic blocks or magnetic sheets on the moving mass move relative to the non-magnetic metal conductor and generating electric eddy current motion damping.

4. The eddy current non-tuned mass damper for a wind turbine blade of claim 1, wherein: The left and right ends of the moving mass are respectively provided with a plurality of rolling bearings in the circumferential direction, the inner ring of each rolling bearing is connected with the moving mass, and the outer ring is in contact with the inner wall of the non-magnetic metal conductor and relatively rolls, so that the moving mass is constrained to move linearly without sliding friction by the rolling bearing and the non-magnetic metal conductor.

5. The eddy current non-tuned mass damper for wind power blades according to claim 1, characterized in that: The first braking permanent magnet and the second braking permanent magnet are both in the form of a button type strong magnetic sheet.

6. An eddy current non-tuned mass damper for a wind turbine blade, characterized in that: The electric eddy current damping structure part comprises a moving mass, a non-magnetic metal conductor and a permanent magnet, the non-magnetic metal conductor is in a hollow structure, the moving mass is made of a non-magnetic metal material, is installed in the hollow interior of the non-magnetic metal conductor and can move linearly to and fro left and right in the non-magnetic metal conductor, the permanent magnet comprises a first permanent magnet arranged on the moving mass and a second permanent magnet arranged on the non-magnetic metal conductor, and the magnetic poles of the first permanent magnet and the second permanent magnet are opposite to each other to generate repulsive magnetic force, so that the moving mass is constrained to move linearly in a magnetic suspension mode by the first permanent magnet and the second permanent magnet, and the first permanent magnet can move synchronously with the moving mass and relatively with the non-magnetic metal conductor to generate electric eddy current motion damping therebetween to dissipate the first-order vibration energy of the blade oscillation, and the moving mass relatively moves with the second permanent magnet to generate electric eddy current motion damping therebetween to dissipate the first-order vibration energy of the blade oscillation; the electric eddy current braking damping structure part comprises a first braking permanent magnet, a second braking permanent magnet, a first electric eddy current plate and a second electric eddy current plate, the first braking permanent magnet has two pieces arranged at the two ends of the moving mass, the second braking permanent magnet has two pieces arranged at the two ends of the non-magnetic metal conductor, the magnetic poles of the first braking permanent magnet and the second braking permanent magnet are opposite to each other, the first braking permanent magnet and the second braking permanent magnet with opposite magnetic poles are used to slow down and brake the moving mass, thereby avoiding rigid collision of the moving mass with the two ends of the non-magnetic metal conductor, the first electric eddy current plate has two pieces arranged at the two ends of the moving mass and located on the inner side of the first braking permanent magnet, the second electric eddy current plate has two pieces arranged at the two ends of the non-magnetic metal conductor and located on the outer side of the second braking permanent magnet, the moving mass slows down when moving to and fro to the left and right ends, and electric eddy current braking damping is generated between the first electric eddy current plate, the second electric eddy current plate and the permanent magnet to dissipate the first-order vibration energy of the blade oscillation.

7. An eddy current non-tuned mass damper for a wind turbine blade according to claim 6, characterised in that: The cross section of the non-magnetic metal conductor is in the form of a rectangle, the cross section of the moving mass is in the form of a rectangle, a through hole is arranged at the center of the moving mass, the first permanent magnet and the second permanent magnet are both in the form of a button type magnetic sheet, the first permanent magnet is arranged on two opposite edges of the moving mass, the two opposite edges are parallel to the moving direction of the moving mass, and the second permanent magnet is arranged on two opposite edges inside the non-magnetic metal conductor, the two opposite edges are parallel to the moving direction of the moving mass and correspond to the two opposite edges of the moving mass.

8. An eddy current non-tuned mass damper for a wind turbine blade according to claim 6, characterised in that: The first and second braking permanent magnets are both in the form of a button type strong magnetic sheet.

9. A wind turbine blade, characterised in that The blade is provided with the eddy current non-tuned mass damper for wind power blades according to any one of claims 1 to 8, the damper is installed at a position at least 2 / 3 of the length of the blade from the blade root, the movement axis of the damper is consistent with the oscillation direction of the blade, and a lightning arrester contact point is arranged at a position corresponding to the damper on the outside of the skin of the blade.

10. A wind turbine blade according to claim 9, characterised in that: The damper has at least two, one of which has a movement axis consistent with the oscillation direction of the blade, and the other has a movement axis consistent with the flapping direction of the blade.

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