A vibration damping device for an offshore wind turbine tower

Abstract

The application discloses a damping device for offshore wind power tower, aiming at providing a damping device capable of damping two vibration modes and providing multidirectional damping simultaneously. The device comprises a base, a nonlinear energy sink, a restoring mechanism and a control unit. The nonlinear energy sink comprises a mass block assembly and a damping assembly; the mass block assembly comprises a mass end cover and a mass ball; the damping assembly comprises four sets of damping rod systems with the same structure; each set of damping rod system comprises a first damping rod structure, a second damping rod structure, a limiting mechanism for two vibration mode conversion and a flexible contact plate; the restoring mechanism is used for providing a restoring force for the mass ball to return to the center of the motion plane; and the control unit comprises an acceleration gauge for measuring the acceleration of the working platform and a limiting mechanism controller. The device can provide multidirectional damping function, is more suitable for offshore wind power tower with severe external environment and complex load conditions, can control structural vibration in two frequency band ranges, and effectively prolongs the service life of the wind power tower.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and more specifically, to a vibration reduction device for offshore wind turbine towers. Background Technology

[0002] With the development of my country's wind power industry, many wind farms are located in areas frequently hit by typhoons or in earthquake zones. Onshore wind turbine towers, as thin-walled steel structures, are prone to vibration or swaying under external dynamic loads such as earthquakes and wind loads, leading to fatigue failure. Offshore wind turbine towers, compared to onshore towers, are also subject to external loads such as waves and currents, making their external environmental conditions even more severe. Due to the complexity of the external environment, the vibration or swaying of offshore wind turbine towers caused by environmental loads is often not unidirectional, making them more susceptible to fatigue failure or even collapse, resulting in major safety accidents and economic losses.

[0003] Currently, the vibration reduction devices used for wind turbine towers are often tuned mass dampers. However, existing tuned mass dampers can only provide vibration reduction in a fixed direction, or require the addition of a steering device driven by an external force to adjust the vibration reduction direction.

[0004] Currently, offshore wind turbine towers are subjected to loads such as wind, waves, and currents, resulting in vibrations or swaying motions. Due to the complexity of the load conditions, the resulting vibrations or swaying motions are often multidirectional. However, existing tuned mass damping devices suitable for wind turbine towers generally cannot provide multidirectional vibration reduction simultaneously, thus failing to meet the vibration reduction requirements of offshore wind turbine towers.

[0005] Currently, tuned mass damping devices suitable for wind turbine towers can only provide vibration reduction for one mode of vibration of the wind turbine tower (generally the first mode of vibration), and have poor vibration suppression effect on other modes of vibration. Summary of the Invention

[0006] The purpose of this invention is to address the technical deficiencies in the prior art by providing a vibration damping device capable of damping two vibration modes and simultaneously providing multi-directional vibration damping.

[0007] The technical solution adopted to achieve the purpose of this invention is:

[0008] A vibration damping device for offshore wind turbine towers includes a base, a nonlinear energy sink, a recovery mechanism, and a control unit.

[0009] The base has a movable cavity formed by a space enclosed by a moving plane and a cavity wall;

[0010] The nonlinear energy trap includes a mass block assembly and a damping assembly. The mass block assembly includes a mass end cap and a mass ball, with the mass ball placed within the movable cavity. The bottom of the mass end cap has a spherical groove, and the mass ball is placed within the spherical groove, forming a ball-and-socket structure with the mass end cap. The mass ball can reciprocate within the movable cavity in different excitation directions. The damping assembly includes four sets of identical damping rod systems. Each set of damping rod systems includes a first damping rod structure, a second damping rod structure, a limiting mechanism for converting between two vibration modes, and a flexible contact plate. The two ends of the first damping rod structure are fixedly connected to the mass end cap and the flexible contact plate, respectively. One end of the second damping rod structure is hinged to the mass end cap, and the other end is hinged to a sliding motion pair slidably mounted on the first damping rod structure.

[0011] The return mechanism provides a restoring force for the mass ball to return to the center of the plane of motion. The return mechanism includes four return components. Each return component includes a first connecting and limiting end, a pair of first motion mechanism rods, a pair of second motion mechanism rods, and a second connecting and limiting end. The first connecting and limiting end is fixedly connected to the cavity wall. One end of each pair of first motion mechanism rods is spring-hung to the first connecting and limiting end in the horizontal plane, and the other end is spring-hung to one end of each pair of second motion mechanism rods in the horizontal plane. The other end of each pair of second motion mechanism rods is spring-hung to the second connecting and limiting end in the horizontal plane. The second connecting and limiting end is fixedly connected to the mass end cap.

[0012] The control unit includes an accelerometer for measuring the acceleration of the work platform and a limit mechanism controller. The limit mechanism controller controls the action of the limit mechanism according to the acceleration measured by the accelerometer. When the limit mechanism is in the closed state, the first damping rod structure provides damping and stiffness corresponding to the first mode shape. When the limit mechanism is in the activated state, the first damping rod structure and the second damping rod structure together provide damping and stiffness corresponding to the second mode shape.

[0013] The limiting mechanism is disposed on the first damping rod structure between the sliding kinematic pair and the flexible contact plate; the limiting mechanism realizes the conversion between the two vibration modes by restricting the sliding kinematic pair.

[0014] The limiting mechanism includes an electric push rod, a thickened tube, and two limiting blocks. The electric push rod is connected to a motor, and two extended sliders are fixed to the top of the electric push rod. The thickened tube has a limiting block moving channel, and the limiting blocks are placed in the limiting block moving channel. Each limiting block has a groove at its bottom, and the extended sliders are placed in the grooves and slide along the grooves. The limiting mechanism controller is connected to the motor of the electric push rod and controls the extension and retraction of the electric push rod. When the electric push rod retracts, the limiting blocks are placed in the limiting block moving channel, and the sliding of the sliding joint is unrestricted. When the electric push rod extends, the extended sliders push the limiting blocks along the grooves and move them outward along the limiting block moving channel, thereby limiting the sliding of the sliding joint through the two limiting blocks.

[0015] The first damping rod structure includes a first damping inner rod, a first damping outer rod, and a first damper connecting the first damping inner rod and the first damping outer rod; the first damping inner rod is fixedly connected to the mass end cap, and the first damping outer rod is connected to the flexible contact plate; the sliding motion pair is slidably mounted on the first damping outer rod.

[0016] The second damping rod structure includes a second inner damping rod, a second outer damping rod, and a second damper connecting the first inner damping rod and the second outer damping rod; one end of the second inner damping rod is vertically hinged to the mass end cap, and the other end is connected to the second damper; one end of the second outer damping rod is connected to the second damper, and the other end is vertically hinged to the sliding kinematic pair.

[0017] The first damper includes a first top plate, a first damping bottom plate, four first internal springs, a first viscous damper located on the outer ring, a first fixing plate, and a first tensile device; the second damper includes a second top plate, a second damping bottom plate, four second internal springs, a second viscous damper located on the outer ring, a second fixing plate, and a second tensile device; the first internal springs and the second internal springs have different stiffnesses, and the first viscous damper and the second viscous damper have different damping coefficients; the first inner damping rod is fixedly connected to the first damping bottom plate of the first damper, and the first outer damping rod is fixedly connected to the first top plate of the first damper; the second inner damping rod is fixedly connected to the second damping bottom plate of the second damper, and the second outer damping rod is fixedly connected to the second top plate of the second damper.

[0018] The flexible contact plate includes a rigid surface, a flexible surface, and a flexible medium filling the space between the rigid surface and the flexible surface; the rigid surface is fixedly connected to the first damping outer rod; the flexible surface is in close contact with the wind turbine tower wall.

[0019] The four recovery components are arranged in a cross shape around the planar geometric center of the motion plane.

[0020] The total mass of the mass block assembly is 0.5%-2% of the generalized mode mass of wind power; the spherical groove encloses two-thirds of the volume of the mass sphere.

[0021] The first damping rod structure in the four identical damping rod systems is arranged in a cross shape around the geometric center of the plane of motion. The first damping rod structure is welded to the mass end cap and offset from the second connection limiting end by 45°.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. The vibration reduction device of the present invention can provide multi-directional vibration reduction function for wind turbine towers, and is more suitable for offshore wind turbine towers with harsh external environment and complex load conditions.

[0024] 2. The vibration reduction device of the present invention can effectively control structural vibration in two relatively wide frequency bands. At the same time, the combination of two damping methods can be designed in the design stage to reduce the amplitude of the structural dynamic response of offshore wind turbine towers and effectively extend the service life of wind turbine towers.

[0025] 3. After the vibration damping device of the present invention is installed, it only needs to replace the battery of the motor that drives the electric push rod periodically. No additional external power is required, and maintenance is simple. Attached image description:

[0026] Figure 1 The figure shown is a general schematic diagram of the vibration reduction device for offshore wind turbine towers of the present invention;

[0027] Figure 2 The diagram shown is a schematic of a damping rod system;

[0028] Figure 3 The diagram shown is a schematic of the internal structure of the damper.

[0029] Figure 4 The diagram shown is a cross-sectional view of the internal structure of the limit device in the closed state.

[0030] Figure 5 The diagram shown is a cross-sectional view of the internal structure of the limit device in the activated state.

[0031] In the diagram: 1-1 is the cavity wall; 1-2 is the motion plane; 2-1 is the first connecting and limiting end; 2-2 is the first motion mechanism rod; 2-3 is the second motion mechanism rod; 2-4 is the spring hinge; 2-5 is the second connecting and limiting end; 3-1 is the mass end cap; 3-2 is the mass ball; 4-1 is the first damping inner rod; 4-2 is the first damping outer rod; 4-3 is the first damper; 4-4 is the flexible contact plate; 4-5 is the second damping inner rod; 4-6 is the second damper. ; 4-7 is the second damping outer rod; 4-8 is the Hooke hinge; 4-9 is the sliding motion pair; 4-10 is the limiting mechanism; 5-1 is the spring; 5-2 is the top plate; 5-3 is the viscous damping; 5-4 is the damping bottom plate; 5-5 is the fixing plate; 5-6 is the tensile device; 4-9-1 is the electric jack; 4-9-2 is the limiting block; 4-9-3 is the thickened tube; 4-9-4 is the slide groove; 4-9-5 is the extended slider; 6 is the working platform; 7 is the tower wall. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0033] A schematic diagram of the vibration reduction device for offshore wind turbine towers of the present invention is shown below. Figure 1 As shown, it includes a base, a nonlinear energy trap, a recovery mechanism, and a control unit.

[0034] The base has an active cavity formed by the space enclosed by the moving plane 1-2 and the cavity wall 1-1; the base is fixedly installed on the working platform 6 on the top of the wind turbine tower, and both the moving plane 1-2 and the cavity wall 1-1 have certain strength and rigidity.

[0035] The nonlinear energy trap includes a mass block component and a damping component.

[0036] The mass block assembly includes a mass end cap 3-1 and a mass ball 3-2. The mass ball 3-2 is placed within the movable cavity, has a certain mass, and has a smooth surface coated with lubricant. The bottom of the mass end cap 3-1 has a spherical groove that encloses two-thirds of the volume of the mass ball 3-2. The mass ball 3-2, positioned within the spherical groove, forms a ball-and-socket structure with the mass end cap 3-1, allowing the mass end cap 3-1 to push the mass ball 3-2 to reciprocate within the movable cavity in different excitation directions. The total mass of the mass block assembly is 0.5%-2% of the generalized mode mass of wind power. The mass ball 3-2 accounts for 90% of the total mass of the mass block assembly.

[0037] The damping assembly comprises four sets of identical damping rod systems. A schematic diagram of the damping rod systems is shown below. Figure 2As shown, each damping rod system includes a first damping rod structure, a second damping rod structure, a limiting mechanism 4-10 for switching between two vibration modes, and a flexible contact plate 4-4. The two ends of the first damping rod structure are fixedly connected to the mass end cap 3-1 and the flexible contact plate 4-4, respectively. One end of the second damping rod structure is hinged to the mass end cap 3-1, and the other end is hinged to a sliding kinematic pair 4-9 slidably mounted on the first damping rod structure. In this embodiment, the limiting mechanism 4-10 is disposed on the first damping rod structure, located between the sliding kinematic pair 4-9 and the flexible contact plate 4-4; the limiting mechanism 4-10 achieves the switching between the two vibration modes by restricting the sliding kinematic pair 4-9.

[0038] In this embodiment, the first damping rod structure includes a first inner damping rod 4-1, a first outer damping rod 4-2, and a first damper 4-3 connecting the first inner damping rod and the first outer damping rod. The first inner damping rod 4-1 is fixedly connected to the mass end cap 3-1, and the first outer damping rod 4-2 is fixedly connected to the flexible contact plate 4-4; the sliding kinematic pair 4-9 is slidably mounted on the first outer damping rod 4-2. The second damping rod structure includes a second inner damping rod 4-5, a second outer damping rod 4-7, and a second damper 4-6 connecting the first inner damping rod and the second outer damping rod. One end of the second inner damping rod 4-5 is vertically hinged to the mass end cap 3-1 via a Hooke hinge 4-8, and the other end is fixedly connected to the second damper 4-6; one end of the second outer damping rod 4-7 is fixedly connected to the second damper 4-6, and the other end is vertically hinged to the sliding kinematic pair 4-9 via a Hooke hinge 4-8.

[0039] In this embodiment, a schematic diagram of the first damper is shown below. Figure 3As shown, the damper includes a first top plate 5-2, a first damping bottom plate 5-4, four first internal springs 5-1, a first viscous damper 5-3 located on the outer ring and filled with a damping medium (generally silicone oil, linseed oil, machine oil, etc.), a first fixing plate 5-5, and a first tensile device 5-6. The second damper has the same structure as the first damper, including a second top plate, a second damping bottom plate, four second internal springs, a second viscous damper located on the outer ring and filled with a damping medium (generally silicone oil, linseed oil, machine oil, etc.), a second fixing plate, and a second tensile device. The first and second internal springs have different stiffnesses, and the first and second viscous dampers have different damping coefficients. The first tensile device 5-6 is installed on the first fixing plate 5-5 near the bottom of the first damping bottom plate 5-4. The function of the tensile device is to prevent the damper from detaching due to excessive tensile force. The first damping inner rod 4-1 is fixedly connected to the first damping base plate 5-4 inside the first damper 4-3. The first damping outer rod 4-2 is fixedly connected to the first top plate 5-2 of the first damper. The second damping inner rod 4-5 is fixedly connected to the second damping base plate of the second damper 4-6. The second damping outer rod 4-7 is fixedly connected to the second top plate of the second damper.

[0040] The return mechanism provides a restoring force for the mass ball to return to the center of the motion plane. The return mechanism includes four return components, each comprising a first connecting and limiting end 2-1, a pair of first motion mechanism rods 2-2, a pair of second motion mechanism rods 2-3, and a second connecting and limiting end 2-5. The first connecting and limiting end 2-1 is fixedly connected to the cavity wall 1-2. One end of each pair of first motion mechanism rods 2-2 is hinged to the first connecting and limiting end 2-1 in the horizontal plane using spring hinges 2-4, and the other end is hinged to one end of each pair of second motion mechanism rods 2-5 in the horizontal plane using spring hinges. The other end of each pair of second motion mechanism rods 2-3 is hinged to the second connecting and limiting end 2-5 in the horizontal plane using spring hinges. The second connecting and limiting end 2-5 is fixedly connected to the mass end cap 3-1. The four return components are arranged in a cross shape around the geometric center of the motion plane 1-1. When the mass ball 3-2 is located at the geometric center of the motion plane 1-2, the spring hinge 2-4 angles of each component of the return mechanism are set to the initial angles, so that the return mechanism can provide the mass ball 3-2 with a restoring force to return to the center of the motion plane 1-2.

[0041] The control unit includes an accelerometer for measuring the acceleration of the work platform 6 and a limit mechanism controller. The limit mechanism controller controls the movement of the limit mechanisms 4-10 based on the acceleration measured by the accelerometer. When the limit mechanisms are in the closed state, the first damping rod structure provides damping and stiffness corresponding to the first mode shape, while the second damping rod does not provide damping and stiffness. When the limit mechanisms are in the activated state, the first and second damping rod structures jointly provide damping and stiffness corresponding to the second mode shape.

[0042] In this embodiment, the limiting mechanism 4-10 is disposed on the first damping outer rod 4-2 of the first damping rod structure, located between the sliding kinematic pair 4-9 and the flexible contact plate 4-4, as shown in the schematic diagram. Figure 4 As shown, the limiting mechanism 4-10 includes an electric push rod 4-9-1, a thickened tube 4-9-3, and two limiting blocks 4-9-2. Both ends of the thickened tube 4-9-3 are welded to the first damping outer rod 4-2. The electric push rod 4-9-1 is connected to a motor, which is battery-powered. Two extended sliders 4-9-5 are fixed to the top of the electric push rod 4-9-1. The thickened tube 4-9-1 is located inside the first damping outer rod 4-2, increasing the wall thickness of the entire limiting mechanism area. It has a moving channel for the limiting blocks and provides a certain strength for the extended limiting blocks 4-9-2, which are placed within the moving channel. Each limiting block 4-9-2 has a groove 4-9-4 at its bottom, and the extended sliders 4-9-5 are placed within and slide along the grooves. The limiting mechanism controller is connected to the motor of the electric push rod to control its extension and retraction.

[0043] Under normal circumstances, the limiting mechanism is in the closed state, the electric push rod 4-9-1 is in the retracted state, and the two limiting blocks 4-9-2 are in the closed state. The limiting blocks are placed in the limiting block moving channel, and the sliding motion pair 4-9 is unrestricted. At this time, only the first damper 4-3 provides damping and stiffness. At this time, the damping coefficient and spring stiffness of the entire device are the damping coefficient and spring stiffness of the first damper. The designed damping coefficient and designed spring stiffness of the first damper make the natural frequency of the entire vibration reduction device close to the first-order frequency of the tower, thus achieving the vibration reduction effect of the first-order vibration mode.

[0044] When the second-order frequency is more pronounced than the first-order frequency in the signal transmitted by the accelerometer of the working platform within a certain time range, the limit mechanism controller sends a control signal to drive the electric push rod 4-9-1 to extend via a motor. The limit mechanism is then in the activated state. The electric push rod drives the extended slider 4-9-5 to push the limit block 4-9-2 outward along the limit block moving channel along the slide groove 4-9-4, lifting the two limit blocks 4-9-2. When the first damping inner rod and the first damping outer rod move relative to each other, the two limit blocks 4-9-5 restrict the sliding motion pair 4-9 from sliding, thereby allowing the second damping rod structure to provide damping and stiffness. At this time, the spring stiffness and damping coefficient of the entire device are numerically equal to the first damper plus the second damper. The design damping coefficient and design spring stiffness of the first damper plus the design damping coefficient and design spring stiffness of the second damper make the natural frequency of the entire vibration reduction device close to the second-order frequency of the tower, achieving a vibration reduction effect on the second-order vibration mode.

[0045] In this embodiment, the first damping rod structure in the four sets of damping rod systems with identical structures is arranged in a cross shape around the geometric center of the motion plane 1-2. The first damping rod structure is welded to the mass end cap 3-1 and is offset by 45° from the second connection limiting end 2-5.

[0046] In this embodiment, the flexible contact plate 4-4 includes a rigid surface, a flexible surface, and a flexible medium filling the space between the rigid and flexible surfaces. The rigid surface is fixedly connected to the first damping outer rod; the flexible surface is in close contact with the wind turbine tower wall 7 to avoid damage to the tower wall of the entire device.

[0047] The vibration reduction device of this invention can provide multi-directional vibration reduction for wind turbine towers, and is more suitable for offshore wind turbine towers with harsh external environments and complex load conditions. It can effectively control structural vibration in two relatively wide frequency bands, reduce the amplitude of the structural dynamic response of offshore wind turbine towers, and effectively extend the service life of wind turbine towers.

[0048] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A vibration damping device for offshore wind turbine towers, characterized in that, Includes a base, a nonlinear energy trap, a recovery mechanism, and a control unit; The base has a movable cavity formed by a space enclosed by a moving plane and a cavity wall; The nonlinear energy trap includes a mass block assembly and a damping assembly. The mass block assembly includes a mass end cap and a mass ball, with the mass ball placed within the movable cavity. The bottom of the mass end cap has a spherical groove, and the mass ball is placed within the spherical groove, forming a ball-and-socket structure with the mass end cap. The mass ball can reciprocate within the movable cavity in different excitation directions. The damping assembly includes four sets of identical damping rod systems. Each set of damping rod systems includes a first damping rod structure, a second damping rod structure, a limiting mechanism for converting between two vibration modes, and a flexible contact plate. The two ends of the first damping rod structure are fixedly connected to the mass end cap and the flexible contact plate, respectively. One end of the second damping rod structure is hinged to the mass end cap, and the other end is hinged to a sliding motion pair slidably mounted on the first damping rod structure. The return mechanism provides a restoring force for the mass ball to return to the center of the plane of motion. The return mechanism includes four return components. Each return component includes a first connecting and limiting end, a pair of first motion mechanism rods, a pair of second motion mechanism rods, and a second connecting and limiting end. The first connecting and limiting end is fixedly connected to the cavity wall. One end of each pair of first motion mechanism rods is spring-hung to the first connecting and limiting end in the horizontal plane, and the other end is spring-hung to one end of each pair of second motion mechanism rods in the horizontal plane. The other end of each pair of second motion mechanism rods is spring-hung to the second connecting and limiting end in the horizontal plane. The second connecting and limiting end is fixedly connected to the mass end cap. The control unit includes an accelerometer for measuring the acceleration of the work platform and a limit mechanism controller. The limit mechanism controller controls the movement of the limit mechanism according to the acceleration measured by the accelerometer. When the limit mechanism is in the closed state, the first damping rod structure provides damping and stiffness corresponding to the first mode shape. When the limit mechanism is in the activated state, the first damping rod structure and the second damping rod structure together provide damping and stiffness corresponding to the second mode shape. The limiting mechanism is disposed on the first damping rod structure between the sliding motion pair and the flexible contact plate; the limiting mechanism realizes the conversion between the two vibration modes by restricting the sliding motion pair; The limiting mechanism includes an electric push rod, a thickened tube, and two limiting blocks. The electric push rod is connected to a motor, and two extended sliders are fixed to the top of the electric push rod. The thickened tube has a limiting block moving channel, and the limiting blocks are placed in the limiting block moving channel. Each limiting block has a groove at its bottom, and the extended sliders are placed in the grooves and slide along the grooves. The limiting mechanism controller is connected to the motor of the electric push rod and controls the extension and retraction of the electric push rod. When the electric push rod retracts, the limiting blocks are placed in the limiting block moving channel, and the sliding of the sliding joint is unrestricted. When the electric push rod extends, the extended sliders push the limiting blocks along the grooves and move them outward along the limiting block moving channel, thereby limiting the sliding of the sliding joint through the two limiting blocks.

2. The vibration damping device for offshore wind turbine towers according to claim 1, characterized in that, The first damping rod structure includes a first damping inner rod, a first damping outer rod, and a first damper connecting the first damping inner rod and the first damping outer rod; the first damping inner rod is fixedly connected to the mass end cap, and the first damping outer rod is connected to the flexible contact plate; the sliding motion pair is slidably mounted on the first damping outer rod.

3. The vibration damping device for offshore wind turbine towers according to claim 2, characterized in that, The second damping rod structure includes a second inner damping rod, a second outer damping rod, and a second damper connecting the second inner damping rod and the second outer damping rod; one end of the second inner damping rod is vertically hinged to the mass end cap, and the other end is connected to the second damper; one end of the second outer damping rod is connected to the second damper, and the other end is vertically hinged to the sliding kinematic pair.

4. The vibration damping device for offshore wind turbine towers according to claim 3, characterized in that, The first damper includes a first top plate, a first damping bottom plate, four first internal springs, a first viscous damper located on the outer ring, a first fixing plate, and a first tensile device; the second damper includes a second top plate, a second damping bottom plate, four second internal springs, a second viscous damper located on the outer ring, a second fixing plate, and a second tensile device; the first internal springs and the second internal springs have different stiffnesses, and the first viscous damper and the second viscous damper have different damping coefficients; the first inner damping rod is fixedly connected to the first damping bottom plate of the first damper, and the first outer damping rod is fixedly connected to the first top plate of the first damper; the second inner damping rod is fixedly connected to the second damping bottom plate of the second damper, and the second outer damping rod is fixedly connected to the second top plate of the second damper.

5. The vibration damping device for offshore wind turbine towers according to claim 2, characterized in that, The flexible contact plate includes a rigid surface, a flexible surface, and a flexible medium filling the space between the rigid surface and the flexible surface; the rigid surface is fixedly connected to the first damping outer rod; the flexible surface is in close contact with the wind turbine tower wall.

6. The vibration damping device for offshore wind turbine towers according to claim 1, characterized in that, The four recovery components are arranged in a cross shape around the planar geometric center of the motion plane.

7. The vibration damping device for offshore wind turbine towers according to claim 1, characterized in that, The total mass of the mass block assembly is 0.5%-2% of the generalized mode mass of wind power; the spherical groove encloses two-thirds of the volume of the mass sphere.

8. The vibration damping device for offshore wind turbine towers according to claim 1, characterized in that, The first damping rod structure in the four identical damping rod systems is arranged in a cross shape around the geometric center of the plane of motion. The first damping rod structure is welded to the mass end cap and offset from the second connection limiting end by 45°.

Images