Damping type floating foundation and wind turbine generator

Abstract

The invention discloses a damping type floating foundation and a wind turbine generator. The damping type floating foundation is composed of at least three floating foundation units, and each floating foundation unit comprises a linear motor and a buoy. The linear motor comprises a motor first part and a motor second part. The piston disc is fixedly connected with a tower of the wind turbine generator directly or through a component, and meanwhile, the piston disc is fixedly connected with the first part of the motor. Piston barrels are arranged at the upper end and the lower end of the buoy, one end of each piston barrel is of an opening structure, and the piston discs can do piston motion in the piston barrels. The second motor component is fixedly connected with the inner wall of the buoy directly or through a connecting component. The beneficial effects are that the linear motor can generate power through primary and secondary relative motion, and electric energy and electromagnetic damping are generated at the same time. Through cooperation of the multiple floating foundation units, the unit structure response amplitude caused by loads generated under external conditions such as wind, waves and surges can be reduced, and the stability of the foundation and the unit is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of wind power generation, and in particular relates to a damping floating foundation and a wind turbine generator set. Background Art

[0002] Wind power is the most valuable and commercially viable power generation method in the renewable energy sector. Available wind energy is widely distributed around the world and has huge reserves. Wind turbines use blades to convert the kinetic energy of air molecules into mechanical energy and ultimately electrical energy. With the large-scale development of onshore wind power projects, modern wind turbine technology has been applied and verified in large quantities. People are shifting their focus to offshore wind power.

[0003] Compared with onshore wind power, offshore wind power has two obvious advantages: 1) wind resources are more abundant and wind speeds are more stable; 2) due to the dense population of coastal cities, the distance to the power load center can be shortened, reducing the investment in building power transmission lines. Among them, the wind resources in the deep sea / offshore are more excellent than those in the near sea. Therefore, the current global development trend of wind energy utilization can be summarized as a shift from onshore to offshore, and from near sea to offshore.

[0004] Due to factors such as the cost and difficulty of foundation construction during construction, (offshore) wind turbines with a water depth of more than 50 meters usually do not use fixed foundations. Then for the development and utilization of deep-sea / offshore wind energy, floating foundations have become the main technical route of choice for offshore wind turbines. The long-term operation test results of the Hywind project in Scotland have shown that the power generation efficiency of wind turbines using floating foundations is much higher than that of offshore fixed foundation wind turbines. Consistent with onshore wind power, minimizing the cost per kilowatt-hour is also the goal pursued by offshore wind power development. Therefore, considering the feasibility and economy and other aspects, floating foundations are the main trend of offshore wind power in the future.

[0005] After years of development, floating foundations have formed several mainstream technical routes such as semi-submersible, tension leg and SPAR. Since wind turbines lack the direct constraints of the earth on the foundation, floating foundations and the nacelles and impellers on the towers have increased the freedom of movement. In other words, no matter which technology is chosen, under the combined effects of various external operating conditions such as wind, waves and surges, wind turbines using floating foundations will produce more and more complex operating postures. These situations should be taken into account when designing wind turbines and corresponding effective measures should be taken to ensure stable operation of the units.

[0006] In current technology, the tower of a wind turbine is rigidly connected to a floating foundation. Specifically, the tower is fixedly connected (i.e., rigidly connected) to the buoy (a floating body that generates buoyancy) of the floating foundation. On the one hand, during normal operation of a wind turbine or during strong wind conditions (such as typhoons), the loads (such as thrust and additional bending moment, etc.) generated by the impeller act along the tower to the floating foundation. Due to the limited rigidity of seawater, the entire wind turbine will experience large-scale drift, floating, oscillation, swing, and deflection movements (structural response); on the other hand, when waves and other fluctuations impact the large-volume component of the floating foundation, the floating foundation drives the entire unit to also experience significant drift, floating, oscillation, swing, and deflection movements (structural response). These structural responses further complicate the posture of the impeller, affect the operation of the wind turbine, and even cause a vicious cycle (i.e., the operation of the impeller affects the structural response of the foundation in seawater, and the structural response of the foundation in seawater in turn affects the operation of the impeller), causing the system to lose stability.

[0007] In order to solve the above problems, the latest technical solutions choose to add passive or actively controlled damping devices inside the conventional floating foundation (such as buoys) to increase the damping of the entire floating foundation or even the unit system, in order to reduce the structural response amplitude of the unit under external influences and improve the stability of the system (at least the stability of structural dynamics). However, these latest technical solutions still have the following problems: 1) The actual scale of the floating foundation of large offshore units is ignored, and the required adjustable damping devices are large in size and complex in structure, resulting in high device costs; 2) The working process of these floating foundation (or even the entire system) damping devices is actually an energy dissipation process, which does not bring direct benefits to the unit, and the effect of increasing damping has yet to be verified. Therefore, the actual cost-effectiveness of this damping device is low; 3) It can only alleviate the stability problem of the entire unit caused by the impact of wave fluctuations to a certain extent, and still cannot solve the problem of unit stability caused by the load brought by the impeller. Summary of the invention

[0008] In order to solve at least one of the above technical problems, a damping floating foundation is provided in a first aspect, which is composed of at least three floating foundation units; the floating foundation unit includes a linear motor and a pontoon; the linear motor includes a first motor component and a second motor component, the first motor component and the second motor component are coaxial, and part of the first motor component is arranged inside the second motor component; at the same time, the first motor component and the second motor component can generate electric energy through relative linear motion; The floating foundation unit also includes two piston disks, one of which is directly fixedly connected to the wind turbine tower or fixedly connected to the wind turbine tower through a component, and both of the piston disks are fixedly connected to the first component of the motor; piston cylinders are provided at both ends of the buoy close to and away from the wind turbine tower, one end of the piston cylinder is an open structure, the piston disk is provided inside the piston cylinder, and the piston disk can perform piston motion along the inner wall of the piston cylinder; the second component of the motor is fixedly connected to the inner wall of the buoy directly or through a connecting component.

[0009] In a further technical solution, the second motor component includes a motor outer cylinder and a motor end cover, and the motor end covers are arranged at both ends of the motor outer cylinder along the axial direction; the inner wall of the buoy is connected to the motor outer cylinder or the motor end cover directly or through a frame; The number of the linear motor arranged in the floating base unit is one, or a plurality of the linear motors are arranged to form a linear motor array.

[0010] The axial length of the first part of the motor is greater than the axial length of the second part of the motor.

[0011] The piston disc is a structure having an outer convex curved surface, and the outer convex curved surface of the piston disc faces the outside of the floating base unit.

[0012] A dynamic sealing device is arranged between the piston disc and the piston cylinder.

[0013] The axial length of the piston cylinder is greater than the maximum distance of relative linear motion between the first motor component and the second motor component.

[0014] The floating basic units are connected by cables.

[0015] In a second aspect, a wind turbine generator set is provided, which includes the aforementioned damped floating foundation; the wind turbine generator set is provided with an AC generator, and the electric energy generated by the AC generator and the linear motor in the damped floating foundation are collected and integrated into the power grid.

[0016] In a further technical solution, the wind turbine generator set comprises a mooring system, and the mooring system is connected to at least one of the floating foundation units.

[0017] The beneficial effects of the present invention are as follows: compared with the latest technical solutions, the present invention changes the connection structure between the ocean, the floating foundation and the wind turbine tower and its upper components. The traditional simple rigid connection between the floating foundation and the tower is abandoned. The linear motor (linear motor) can generate electricity under the condition of relative motion between the primary (or stator) and the secondary (or mover), which can generate electric energy and also bring electromagnetic damping in the process of generating electric energy. Through the coordinated use of multiple floating foundation units, the amplitude of the unit structure response caused by the load generated by the wind on the impeller can be reduced, and the stability of the foundation and the entire unit can be improved; the amplitude of the unit structure response caused by the wave and surge on the floating foundation can also be reduced, and the stability of the unit can be improved. In other words, the unit can have better system stability under the external conditions such as wind, waves and surge (including tide). In addition, while providing electromagnetic damping, the linear motor also generates electric energy, which improves the economy of the floating foundation and the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a rendering of a damping floating foundation according to an embodiment of the present invention; Figure 2 A schematic diagram of the basic composition of a floating foundation unit of a damping floating foundation according to an embodiment of the present invention; Figure 3 A schematic diagram of the connection between a damping floating foundation and a wind turbine tower according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the connection between a damped floating base linear motor and a buoy in an embodiment of the present invention; Figure 5 This is a schematic diagram of the load response effect of a unit according to an embodiment of the present invention; Figure 6 A comparison diagram of the overall structure of a damping floating foundation according to an embodiment of the present invention and a current technical solution; Figure 7 It is an overall schematic diagram of a floating foundation unit of a damping floating foundation according to an embodiment of the present invention; Figure 8 A schematic diagram of the topology of power collection of a unit according to an embodiment of the present invention; Fig. 9 The figure is a schematic diagram of a unit with a damping floating foundation according to an embodiment of the present invention.

[0019] Description of Figure Numbers: 1. Floating base unit, 1.1. Linear motor, 1.11. First part of motor, 1.12. Second part of motor, 1.121. Motor outer cylinder, 1.122. Motor end cover, 1.2. Float, 1.21. Piston cylinder, 1.211. Limiting device, 1.3. Piston disc, 1.31. Dynamic sealing device, 1.4. Linear motor output cable, 2. Tower, 2.1. Component, 3. Wind turbine output cable, 4. Transformer, 5. Submarine cable, 6. Mooring rope.

[0020] It is worth noting that the above drawings are used to illustrate the features of the present invention, and are not intended to show any actual structure or reflect the size, relative proportions and other detailed information of various components. In order to more clearly demonstrate the principles of the present invention and to avoid unnecessary details that make the principles of the present invention unclear, the examples in the figures have been simplified. These illustrations will not cause inconvenience to technicians in the relevant fields in understanding this patent, and the actual embodiment may include more modules or components. DETAILED DESCRIPTION

[0021] In order to make the purpose and technical solution of the embodiment of the present invention clearer, the embodiment of the present invention is fully described below in conjunction with the relevant drawings of the embodiment of the present invention. This patent describes only a part of the embodiments, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] 1. Stability issues faced by wind turbines using floating foundations The main functions of the floating foundation are to provide sufficient buoyancy for the wind turbine installed on it, and to provide sufficient system stiffness to ensure that the unit can reduce the amplitude of movement (such as heave and sway, etc.) in various degrees of freedom (i.e., reduce the amplitude of structural response) under the influence of external conditions such as wind, waves and surge, shorten the time of forced swaying movement, and have better system stability. Due to the lack of direct rigid connection with the seabed, the support stiffness provided by the floating foundation is far inferior to that of the fixed foundation (single pile or jacket foundation). The effects of external conditions such as wind, waves and surge can be mainly divided into two situations: the operating load from the impeller and the load from the ocean: 1) When the impeller is running, the load is transmitted along the tower to the floating foundation. Due to the low stiffness of seawater, the entire unit will sway; 2) Waves and surges act directly on the floating foundation, and the floating foundation drives the entire unit to sway and other movements. Although the final result of these two situations is that the entire unit will sway, the causes of the swaying movement are obviously different. In order to reduce the amplitude of the unit's swaying motion, shorten the time of forced swaying motion, and improve the system's motion stability, it is necessary to propose corresponding solutions based on different inducements. If one technical solution can be used to solve the problems of the above two situations at the same time (the technical effect of the present invention), it would naturally be the best. However, the latest technical solution can only solve the problem described in one of the above situations.

[0023] Among the mainstream floating foundation technologies such as semi-submersible, tension leg and SPAR, the semi-submersible and SPAR floating foundations have a larger amplitude of swaying motion in the water. Although the tension leg floating foundation has a slightly smaller amplitude of swaying motion with the support of the tension mooring system, its mooring system structure is more complex and the cost is higher, so it has not been widely used. In addition, the tension of its mooring system is seriously affected by the ocean current. Once the tension changes, the amplitude of the swaying motion will also change. Therefore, problems such as large amplitude of swaying motion, obvious structural response, and system stability are common in various types of floating foundation technologies.

[0024] 2. The latest structural form of floating foundation The structural form adopted by the latest floating foundation technical solutions can be summarized as follows: the wind turbine tower is rigidly connected to the floating foundation, a damper (such as a liquid damper and a mass damper) is added inside the floating foundation, or an adjustable device (such as a retractable mechanical structure) is rigidly added to the outside of the floating foundation to be in direct contact with the ocean, which can passively or actively provide system damping, and some can even use wave energy to generate electricity. A common problem with these technical solutions is that although a damping device is added to the floating foundation, even if the system damping can be increased, the floating foundation is directly rigidly connected to the tower on the one hand, and the connection relationship between the components of the floating foundation as a whole is also rigid on the other hand. Therefore, in terms of suppressing the amplitude of swaying motion and reducing structural response, only problems with a single degree of freedom (such as perpendicular to the sea surface or parallel to the sea surface) can be solved. However, the structural response or swaying motion caused by the load of the wind turbine is more complex and involves multiple degrees of freedom. Therefore, it can be concluded that the latest floating foundation technology solutions are relatively simple in effect in suppressing swaying motion and can only solve part of the problem. In addition, most of the latest floating foundation technology solutions can only target the unit structural response or swaying motion caused by the direct action of waves on the floating foundation, and have no obvious inhibitory effect on the unit structural response caused by the impeller load.

[0025] 3. Basic Concept of the Invention The basic concept and core technical features of the embodiments of the present invention can be summarized as follows: 1) The floating foundation adopts a plurality of floating foundation units arranged in a dispersed manner, and there is no rigid connection between each floating foundation unit; 2) Each floating foundation unit is not simply directly rigidly connected to the tower of the wind turbine generator set, and a linear motor (linear motor) is arranged inside the floating foundation unit; 3) The first motor component of the linear motor is fixedly connected to the tower and the piston disk, and the second motor component of the linear motor is fixedly connected to the buoy of the floating foundation, and the piston disk can perform piston motion in the piston cylinder arranged on the buoy.

[0026] The first motor component and the second motor component of the linear motor can generate electrical energy when relative linear motion occurs. The linear motor can also provide electromagnetic damping while generating electrical energy during relative linear motion. This allows the linear motor to provide damping for each floating base unit when performing heaving motion, thereby reducing the structural response of the floating base unit. And whether the heaving motion is caused by the impeller load or the seawater load, it can play a role in suppressing the heaving motion amplitude and reducing the time of forced heaving motion.

[0027] Furthermore, when multiple such floating foundation units are used in combination, since the floating foundation units are not rigidly connected together, that is, the structural response or heaving motion of each floating foundation unit is independent, there is no "one hair moves the whole body" effect, so this floating foundation can suppress the forced motion amplitude of the unit in multiple degrees of freedom (such as pitching forward and backward, swaying left and right, etc.), thereby improving the stability of the system.

[0028] 4. An embodiment of a wind turbine generator system using a damping floating foundation A damping floating foundation is composed of at least three floating foundation units (1). The number of floating foundation units (1) is determined by comprehensively considering the structural stability of the unit, the tower structure form and other factors. For example, in some embodiments, the tower of the unit adopts a truss structure, and the truss structure is generally a four-tube lattice column. Then each main chord can be connected to a floating foundation unit (1), so the number of floating foundation units (1) can be four (such as Figure 1 as shown).

[0029] like Figure 2 As shown, the floating base unit (1) mainly includes a linear motor (1.1) and a pontoon (1.2). The linear motor (1.1) includes a first motor component (1.11) and a second motor component (1.12), wherein the first motor component (1.11) and the second motor component (1.12) can correspond to the primary (or stator) and the secondary (or mover) in a general linear motor (1.1) (or linear motor). Due to the particularity of the technical solution, the first motor component (1.11) and the second motor component (1.12) do not correspond one-to-one to the primary and the secondary, that is, in an actual embodiment, the first motor component (1.11) or the second motor component (1.12) can be the primary or the secondary. The specific configuration scheme is determined based on the overall design result of the system.

[0030] Since a linear motor (1.1) is used, the first motor component (1.11) and the second motor component (1.12) have the characteristic of being coaxial, and the first motor component (1.11) and the second motor component (1.12) generate electrical energy through relative linear motion. In particular, in this solution, only a portion of the first motor component (1.11) is located inside the second motor component (1.12). In other words, at any time when the first motor component (1.11) and the second motor component (1.12) undergo relative linear motion, only a portion of the first motor component (1.11) is located inside the second motor component (1.12).

[0031] The floating foundation unit (1) further comprises two piston discs (1.3). One of the piston discs (1.3) is located at the upper part of the floating foundation unit (1) and is directly fixedly connected to the wind turbine tower (such as Figure 3 As shown in the figure on the right, it is generally the case that the wind turbine adopts a lattice tower), or is fixedly connected to the wind turbine tower through a component (2.1) (such as Figure 3 As shown in the left figure, which is generally the case of a wind turbine using a steel cylindrical tower, another piston disc (1.3) is located at the bottom of the floating foundation unit (1), and both piston discs (1.3) are fixedly connected to the first component (1.11) of the motor.

[0032] The buoy (1.2) is close to and away from the two ends of the wind turbine tower, that is, Figure 2 The upper and lower ends of the buoy (1.2) shown in the figure are provided with a piston cylinder (1.21). One end of the piston cylinder (1.21) is an open structure, and the piston disc (1.3) can perform piston motion inside the piston cylinder (1.21) along the inner wall of the piston cylinder (1.21). It is worth noting that in this embodiment, the piston cylinder (1.21) is actually a part of the buoy (1.2), that is, the upper and lower ends of the buoy (1.2) are actually open structures. In other embodiments, the buoy (1.2) and the piston cylinder (1.21) can be two independent structures, but the piston cylinder (1.21) needs to be fixedly connected to the buoy (1.2).

[0033] The second motor component (1.12) is fixedly connected to the inner wall of the buoy (1.2) directly or through a connecting member. The second motor component (1.12) includes a motor outer cylinder (1.121) and a motor end cover (1.122), wherein the motor end cover (1.122) is connected to the motor outer cylinder (1.121) at both ends along the axial direction. In this embodiment, Figure 4 As shown, the second part of the motor is connected to the inner wall of the buoy (1.2) through the motor end cover (1.122). It is worth noting that in some embodiments, if a floating base unit (1) has only one linear motor (1.1), and the size of the motor meets the actual processing and manufacturing capabilities, it is entirely possible to combine the outer cylinder of the second part (1.12) of the motor in the linear motor and the wall of the buoy (1.2) into one in the design.

[0034] Through the above embodiments, it can be found that the novelties and advantages of the present invention are: The floating foundation is divided into at least three floating foundation units (1). These floating foundation units (1) are not rigidly connected together and can move independently in many degrees of freedom.

[0035] Each floating base unit (1) can be divided into two parts from a structural point of view: the first part is composed of a piston disc (1.3) and a first motor component (1.11) of a linear motor, and the first part is fixedly connected to the tower of the wind turbine and moves together; the second part is composed of a piston cylinder (1.21), a buoy (1.2) and a second motor component (1.12) of the linear motor, and the three components of the second part are fixedly connected together and move together. At the same time, a linear relative motion (along the axial direction of the linear motor (1.1)) can occur between the first part and the second part, which can be said to be along a direction perpendicular to the sea level or vertical in this embodiment. From the perspective of the entire wind turbine, the object formed by the turbine tower or part of the tower, the piston disc (1.3) and the first motor component (1.11) connected to the current floating foundation unit (1), and the object formed by the piston cylinder (1.21), the buoy (1.2) and the second motor component (1.12) can undergo vertical relative movement, unlike the current technical solution where everything (the wind turbine tower, the buoy (1.2) and the damping device) are rigidly connected together. At the same time, the object formed by the piston cylinder (1.21), the buoy (1.2) and the second motor component (1.12) can move with multiple degrees of freedom relative to the ocean.

[0036] Each floating foundation unit (1) in the floating foundation can generate its own independent structural response according to the load from the ocean or the tower of the wind turbine - a linear motion is generated between the first motor component (1.11) and the second motor component (1.12) in the linear motor. Electric energy is generated in this process, which is equivalent to forming electromagnetic damping. This electromagnetic damping is very beneficial for suppressing the vertical swing of each floating foundation unit (1). In addition, each floating foundation unit (1) can respond independently according to the load from the surrounding ocean or the connected tower, so that multiple floating foundation units (1) as a whole can produce the effect of suppressing the amplitude of forced motion of more degrees of freedom, such as the forward and backward pitch and left and right swing of the unit (such as Figure 5 This is not possible with current technology.

[0037] At present, there are some technologies that rely on the removal or absorption of seawater to generate damping. Such technologies are overly dependent on seawater, and the damping they generate will obviously change with the characteristics of seawater (such as temperature, density and flow rate, etc.). Therefore, the actual damping generated is uncertain and not universal. In addition, the efficiency of the equipment to remove or absorb seawater may change over time (such as corrosion causing the cross-section to become smaller). The electromagnetic damping that each floating foundation unit (1) in this solution can provide is very clear during design (only related to parameters such as the power of the motor), and can be obtained in advance through calculation. And it will not change with changes in the external environment.

[0038] At present, the latest technology has a method of rigidly connecting the adjustable device to the floating foundation, and the adjustable device is in direct contact with the sea; there is also a method of arranging a damping device (such as a mass block and liquid damping, etc.) inside the buoy (1.2) of the floating foundation. The structure of the floating foundation in these technical solutions is summarized and compared with the solution proposed in this invention (such as Figure 6 As shown in the figure, it is not difficult to find that in the latest technology, the floating foundation, especially the buoy, is rigidly connected to the tower and the upper part of the wind turbine. If there are multiple buoys in the floating foundation, they are also rigidly connected. This shows that in the latest technical solutions, the floating foundation, the tower and the upper part can be regarded as an integral structure, and there is no degree of freedom between them. The solution proposed in the present invention is significantly different. Each buoy (1.2) independently provides vertical freedom relative to the tower and the upper part. The vertical movement amplitude of each buoy (1.2) (i.e., the floating foundation unit (1)) relative to the tower and the upper part can be different at any time and is adaptive.

[0039] In a further technical solution: The number of linear motors (1.1) provided in the floating base unit (1) can be only one, or a plurality of linear motors (1.1) can be provided to form a linear motor array. The number of linear motors (1.1) is determined by comprehensively considering the scale of the floating base unit (1), the damping value required to be provided by the linear motor (1.1) in the structural dynamics of the unit, the processing capacity of the linear motor (1.1), and the cost of the floating base unit (1). Specific calculations and analyses are required in each embodiment. In this embodiment, the number of linear motors (1.1) provided in the floating base unit (1) is only one, and the linear motor (1.1) is connected to the inner wall of the buoy (1.2) through two end covers.

[0040] When there are multiple linear motors (1.1) in a floating base unit (1), the solutions that can be adopted are: 1) only two upper and lower connecting end covers are provided, the two connecting end covers are connected to the inner wall of the buoy (1.2), and all the motor outer cylinders (1.121) are connected to these two end covers; 2) an additional frame is used to connect to each linear motor (1.1), and the specific connection part can be the motor outer cylinder (1.121) or the motor end cover (1.122), and the end of the frame is connected to the inner wall of the buoy (1.2).

[0041] Based on the description of the above content: only part of the first motor component (1.11) is located inside the second motor component (1.12), and in fact, the axial length of the first motor component (1.11) (which is also the direction in which the first motor component (1.11) and the second motor component (1.12) of the linear motor move relative to each other) is greater than the axial length of the second motor component (1.12) (e.g. Figure 4 This arrangement takes into account the actual travel of the motor first component (1.11) and the piston disc (1.3) when they perform linear motion relative to the motor second component (1.12), the float (1.2) and the piston cylinder (1.21), as well as the need for the linear motor to generate electrical energy. Similarly, the axial length of the piston cylinder (1.21) is greater than the maximum distance (travel) required for relative linear motion between the motor first component (1.11) and the motor second component (1.12).

[0042] The piston disc (1.3) is a structure with an outward convex surface, and the side of one piston disc (1.3) close to the wind turbine tower is an outward convex surface, and the side of the other piston disc (1.3) close to the sea is an outward convex surface. Figure 7 As shown, in this embodiment, the piston disk (1.3) is an outwardly convex curved disk whose outer surface is a sphere or ellipsoid. In some other embodiments, the piston disk (1.3) may also be a conical disk or a disk of other structural forms. This design mainly considers that the axial bearing capacity of the outwardly convex curved disk in at least one direction is strong enough. Although one of the piston disks (1.3) is the uppermost end of the floating foundation unit (1), it is very likely to be located in the seawater in some working conditions. In this case, the vertical pressure of the seawater on the piston disk (1.3) also needs to be considered. At the same time, the piston disk (1.3) located at the bottom of the floating foundation unit (1) also adopts the same structure. In some embodiments, the upper and lower piston disks (1.3) in the same floating foundation unit (1) may have different outwardly convex curved surface structures. In some embodiments, in order to ensure the buoyancy of the floating foundation unit (1), the support tower (2) is set to a piston disk (1.3) of the floating foundation unit (1) (i.e., the piston disk at the bottom of the floating foundation unit (1)) of the wind turbine tower (2) as a hollow thin shell structure with a certain volume. Similar to the structure of the buoy (1.2), a damping type limit device composed of a wedge block and a spring can also be arranged between the piston cylinder (1.21) and the piston plate (1.3) to provide an auxiliary function for the floating foundation unit (1) to support the tower frame (2).

[0043] The piston disc (1.3) performs piston motion in the piston barrel. Since the piston disc (1.3) and the piston cylinder (1.21) may be located in seawater, a dynamic sealing device (1.31) is provided between the piston cylinder (1.21). At the same time, a limit device (1.211) is also provided at the upper and lower ends of the piston cylinder (1.21) to limit the relative motion distance between the piston disc (1.3) and the first motor component (1.11) and the second motor component (1.12), and between the buoy (1.2) and the piston cylinder (1.21). This also reflects, to a certain extent, the range of adjustment that each floating foundation unit (1) can make according to the load from the tower or the ocean.

[0044] The cooling of the linear motor is also a problem worthy of attention. In actual implementation, a water cooling system (such as a water cooling backpack) can be provided on the linear motor (1.1), and the water cooling system can be connected to the inner wall of the buoy (1.2) or the piston cylinder (1.21). Since the buoy (1.2) or the piston cylinder (1.21) is in direct contact with the ocean, the water cooling system provided on the linear motor (1.1) cools down the water and then returns again, forming circulating water cooling.

[0045] A wind turbine using a damped floating foundation: The wind turbine is provided with a wind generator on the upper part of the tower. If it is a doubly-fed wind turbine, it is an asynchronous AC generator, and the stator is directly connected to the grid, and the rotor is connected to the grid through a converter. If it is a direct-drive or medium-speed wind turbine, it is a synchronous AC generator, and the stator is connected to the grid through a converter. If the linear motor (1.1) provided in the damped floating foundation is an AC generator, the linear motor (1.1) can be connected to the grid through a converter. The electric energy generated by the wind turbine and the electric energy generated by the linear motor (1.1) are combined and connected to the grid. A possible structural topology is as follows: Figure 8 As shown: the output cable (1.4) of the wind turbine and the output cable (1.5) of the linear motor can be connected to the transformer (4) located at the bottom of the tower (2) and connected to the power grid through the submarine cable (5).

[0046] The mooring system in the wind turbine generator set can be connected to one or more floating foundation units (1), and the mooring rope (6) in the mooring system can be non-tensioned. When the mooring rope (6) is connected to one of the floating foundation units (1), a single-point mooring (such as Fig. 9 as shown).

[0047] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "up, down, front, back, left and right" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0048] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or 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 according to specific circumstances.

[0049] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A damping floating foundation, characterized in that: It is composed of at least three floating base units (1); The floating base unit (1) comprises a linear motor (1.1) and a buoy (1.2); The linear motor (1.1) comprises a first motor component (1.11) and a second motor component (1.12), the first motor component (1.11) and the second motor component (1.12) being coaxial, and a portion of the first motor component (1.11) being arranged inside the second motor component (1.12); and the first motor component (1.11) and the second motor component (1.12) are capable of generating electric energy through relative linear motion; The floating foundation unit (1) further comprises two piston discs (1.3), one of which is directly fixedly connected to the wind turbine tower, or fixedly connected to the wind turbine tower via a component (2.1), and both of which are fixedly connected to the first motor component (1.11); piston cylinders (1.21) are provided at both ends of the buoy (1.2) close to and away from the wind turbine tower, one end of the piston cylinder (1.21) is an open structure, the piston disc (1.3) is provided inside the piston cylinder (1.21), and the piston disc (1.3) can perform piston motion along the inner wall of the piston cylinder (1.21); The second motor component (1.12) is fixedly connected to the inner wall of the buoy (1.2) directly or through a connecting member.

2. A damping floating foundation according to claim 1, characterized in that: The second motor component (1.12) comprises a motor outer cylinder (1.121) and a motor end cover (1.122), and the motor end covers (1.122) are arranged at both ends of the motor outer cylinder (1.121) along the axial direction; the inner wall of the buoy (1.2) is connected to the motor outer cylinder (1.121) or the motor end cover (1.122) directly or through a frame.

3. A damping floating foundation according to claim 1, characterized in that: The number of the linear motor (1.1) arranged in the floating base unit (1) is one, or a plurality of the linear motors (1.1) are arranged to form a linear motor array.

4. A damping floating foundation according to claim 1, characterized in that: The axial length of the first motor component (1.11) is greater than the axial length of the second motor component (1.12).

5. The damping floating foundation according to claim 1, characterized in that: The piston disc (1.3) is a structure having an outer convex curved surface, and the outer convex curved surface of the piston disc (1.3) faces the outside of the floating base unit (1).

6. The damping floating foundation according to claim 1, characterized in that: A dynamic sealing device (1.31) is provided between the piston disc (1.3) and the piston cylinder (1.21).

7. The damping floating foundation according to claim 1, characterized in that: The axial length of the piston cylinder (1.21) is greater than the maximum distance of relative linear motion between the first motor component (1.11) and the second motor component (1.12).

8. The damping floating foundation according to claim 1, characterized in that: The floating foundation units (1) are connected via cables.

9. A wind turbine generator set, characterized in that: Comprising a damped floating foundation as claimed in any one of claims 1 to 8; the wind turbine set is provided with an AC generator, and the electric energy generated by the AC generator and the linear motor (1.1) in the damped floating foundation is collected and then connected to a power grid.

10. A wind turbine generator set according to claim 9, characterized in that: The wind turbine generator set comprises a mooring system, wherein the mooring system is connected to at least one of the floating foundation units (1).

Images