EP4157704A1

EP4157704A1 - Floating structure

Info

Publication number: EP4157704A1
Application number: EP21733860.7A
Authority: EP
Inventors: Renzo RIGHINI; Mirco Armando RAFFUZZI
Original assignee: F lli Righini Srl
Current assignee: F lli Righini Srl
Priority date: 2020-05-29
Filing date: 2021-05-28
Publication date: 2023-04-05
Also published as: WO2021240449A1

Abstract

A floating structure (1) provided with a hollow body (10) elongated according to a longitudinal axis (D), which is provided with a first end (12) delimited at the top by a base (121) prearranged to support an operating unit (20)(ET) and delimited, on the side opposite to the first end (12), by a second end (14) prearranged to operate submerged and to support at least two arms (102)(102'); an anchorage means (40) being associated with the hollow body (10) to fix it to the ground (F); the anchorage means (40) comprising a plurality of anchoring members (42)(42') and a connection member (44)(44') arranged between each said anchoring member (42)(42') and said hollow body (10); the connection members (44)(44') having the same longitudinal extension; means (100) for adjusting the distance being arranged between the first end (12) and each anchoring member (42) in order to vary the inclination of the hollow body (10) with respect to the ground (F).

Description

"FLOATING STRUCTURE"

DESCRIPTION

The present invention relates to a floating structure prearranged to support a wind generator. In particular, the present invention refers to a floating structure prearranged to support a wind generator and suitable to be installed in deep water. More in detail, the present invention refers to a floating structure prearranged to support a wind generator and suitable to be installed in deep water by a plurality of arms which can be stably connected to the ground by anchoring members.

DESCRIPTION OF THE STATE OF THE ART

In the field of structures that can be installed far away from the coast to be used in the power generation field, those provided with a base dedicated to support of an operating unit provided with a wind turbine are known. The correct functioning of these operating units is strongly conditioned by the maintenance of the correct absolute inclination of this base and, of course, of the wind turbine tower supported by the latter, which is provided with a current generator.

When the depth of the water allows it, the structures are provided with a plurality of legs that end with feet predesigned to stably engage the ground in a different way in relation to the morphological and physical characteristics of the seabed. In some cases, it may be feasible to permanently fix the feet by means of log bolts or pilings.

In other cases, when the water in the installation area is particularly deep, the types of floating structures most used are two, each specifically designed to keep its own base vertically stable. In particular, reaction stability structures (or systems) and intrinsic stability structures (or systems) are known.

Reaction stability systems are those in which the equilibrium of the structure is conditioned by the combined presence of wind, waves, currents for which positions are allowed in which the base is not temporarily horizontal but becomes so as soon as the external conditions allow it.

In some cases, these systems adopt the single-cylinder floating body anchored to the ground in various ways where said floating body carries the base transversal to its central axis. In this way the tower of the generator has its own axis coaxial with that of the floating body. In this case, the return of the floating body to the vertical position is therefore conditioned by the arrangement of the masses involved and by the conditions of wind, waves and currents. Therefore, the normal operating condition of a structure of this type is to be continuously oscillating. It is easy to understand that the continuous oscillation of the structure obviously entails the impossibility of taking advantage of the maximum efficiency of the generator installed on the respective base; moreover, in said dynamic regime all the components are continuously mechanically stressed. Therefore, these structures must be designed with great care, and with very high costs, if sudden structural and functional failures that can occur due to the tiring nature of the stresses need to be prevented, also because the load cycles are objectively difficult to be modelled a priori.

On the other hand, this type of platform requires the generator to be installed in the high seas after the supporting single-cylinder has been positioned and anchored. It is easy to understand that these installations are decidedly demanding considering that said generators must operate, therefore be installed, in areas with a high wind factor, therefore with perturbations and pronounced wave motion.

Similar problems are encountered in floating island-like systems, in which three floating cylinders are placed in a triangle arrangement and are connected by metal arms, which are also floating.

The wind turbine tower is commonly mounted above one of the three floating cylinders, which in this case could also be pre-mounted on the ground. This structure is more expensive than the first, but suffers from the same problems as it is also subject, albeit to a lesser extent, to the oscillation of the vertical axis (and therefore of the generator) due to wind, waves and currents.

Intrinsic stability systems, on the other hand, are based on articulated parallelogram constructions, in which the masses and anchors are arranged so as to allow the vertical axis of the wind tower to translate exclusively parallel to the vertical axis itself. Even if it is not possible to completely eliminate oscillatory situations, in these systems the base that carries the wind turbine tower is always kept substantially horizontal, thus successfully overcoming the efficiency problems of the previously discussed systems.

Constructively, these systems normally have three diverging arms, which start from the centre where a floating cylinder is located, delimited at the top by the base that carries the tower of the wind generator, and extend towards the vertices of an equilateral triangle. The anchors start from the vertices of the triangle to reach the ground/seabed, to which they are anchored by means of a suction head or dead weights or anchors. It is easy to understand that in order for the wind generator tower to be kept perpendicular to sea level, the anchors of the floating structure must be hooked to bodies lying on the bottom arranged on a substantially horizontal plane. Furthermore, since the anchors must remain perfectly tense, the respective length must be the same and remain unchanged over time.A variation of said length, typically due to different elastic settlements, would lead to the assumption of inclinations of the tower that are probably not functionally acceptable. It is easy to understand that the condition imposed on the hooks of the anchors on the bottom is so unusual that it is impractical, so this solution has been relegated to the last place among those tested, although potentially by far the most valid. As described above, the problem of making a floating structure installable in deep water and suitable for maintaining the respective base in a geographically determined and horizontally oriented position regardless of external, marine and atmospheric, conditions is currently unsolved and represents an interesting challenge for the applicant. In this way, the tower of the supported operating unit would be kept substantially vertical even in rough sea conditions, and the operation of any wind turbine supported by the base would be compatible with the optimal operating conditions.

In consideration of the situation described above, it would be desirable to have a floating structure provided with a base for an operating unit which, in addition to limiting and possibly overcoming the typical drawbacks of the prior art illustrated above, defines a new standard for the field, particularly suitable for high seas wind turbine installations . Floating structures according to the state of the art are known from the following patent documents: CN 102392796, EP 2877 739, EP 2685 093, US 2008/014025, KR 20130087129, WO 2017/157399.

SUMMARY OF THE PRESENT INVENTION

The present invention relates to a floating structure prearranged to support a wind generator. In particular, the present invention refers to a floating structure prearranged to support a wind generator and suitable to be installed in deep water. More in detail, the present invention relates to a floating structure prearranged to support a wind generator and suitable to be installed in deep water by a plurality of arms which can be stably connected to the ground by anchoring members.

The above problems are solved by the present invention according to at least one of the following claims. According to some embodiments of the present invention, a floating structure is provided with a hollow body which is elongated according to a longitudinal axis, is provided with a first end delimited at the top by a base prearranged to support an operating unit and is delimited on a side opposite to said first end, by a second end arranged to operate submerged and to support at least two arms; anchorage means being associated with said hollow body for fixing it to the ground; said anchorage means comprising an anchoring member for each said arm and a connection member arranged between each said anchoring member and a respective said arm; characterized in that said connection members have the same longitudinal extension; distance adjustment means being arranged between said first end and each said anchoring member in order to vary the inclination of the hollow body with respect to the ground. According to a possible constructional variation of the present invention, at least one said connection member comprises a tubular body or a flexible member comprising a cable or several cables.

According to one embodiment, an electronic device provided with a memory unit and a calculation unit electronically connected; at least one inclination sensor being associated with said hollow body and electronically connected to said electronic device in a wired way or remotely to measure deviations of a current position of said base with respect to a given reference position stored by said memory unit.

According to an embodiment, each said arm is hinged to said hollow body in said second end and has a respective free end; said adjustment means comprising a traction device having an adjustable length for each said arm, where each said traction device is arranged between said first end and one said free end to define, according to necessity, a first angle width between said arm and said hollow body.

According to an embodiment, each said traction device comprises a first body made of flexible material connected to said second end or to one said free end by means of the interposition of a first linear actuator electronically connected to said electronic device in a wired or remote way and in a hydraulically sealed manner to a second hydraulic feeding device carried by said base; said first linear actuator being equipped to transmit, in use, information regarding its own operating conditions to said electronic device.

According to an embodiment, each said traction device comprises a hoist provided with a first and a second transmission member connected to said first end and to one said free end of a said arm, respectively.

According to an embodiment, each said traction device comprises a first lever hinged to said first end transversally to said longitudinal axis and a second lever hinged to said free end transversally to the relative said arm.

According to an embodiment, said first lever and said second lever are hinged together by a kinematic pair having an axis transversal to said longitudinal axis; a second linear actuator is electronically connected to said electronic device being coupled to said hollow body in said second end as well as to at least one of said first and second levers; said second linear actuator being equipped to transmit, in use, information regarding its own operating conditions to said electronic device. According to an embodiment, said second linear actuator is coupled to said first and second levers concentrically to said kinematic pair.

According to an embodiment, at least one said connection member is connected to the respective said arm by means of one said free end.

According to an embodiment, said arms are substantially identical to one another and distributed evenly around said axis.

According to an embodiment, said arms are three in number and distributed evenly with respect to said hollow body. According to an embodiment, said arms are two in number and said second given angle has a width comprised within a range of 60° - 150°.

According to an embodiment, a further said connection member is connected to said hollow body in said second end. According to an embodiment, said second end rigidly supports two said arms, each being oriented transversally to said longitudinal axis and being delimited longitudinally by a cylindrical floating body; said adjustment means comprising a third linear actuator for each said anchoring member.

According to an embodiment, each said third linear actuator has an armature coupled in a hinge-like manner to a said connection member and a stem coupled to a said anchoring member; said adjustment means comprising a platform which integrally connects said armatures.

According to an embodiment, at least one said connection member is connected to the respective said arm by said cylindrical body; a further said connection member being connected to said hollow body in said second end. According to an embodiment, each said third linear actuator has an armature obtained in said cylindrical body or in said second end and a stem provided with a head coupled to a said connection member; said adjustment means comprising a platform which integrally connects said anchoring members .

According to an embodiment, the platform supports said electronic device and a first fluid-dynamic feeding device connected in a hydraulically sealed manner to each said third linear actuator and electronically to said electronic device to be operated.

According to an embodiment, each said anchoring member comprises a plate for fixing to the ground provided with a joint.

According to an embodiment, at least one said plate is flat and carries, at the bottom, a hollow tubular body transversal to said plate or a plurality of poles transversal to said plate. According to an embodiment, said base carries three said inclination sensors associated with said hollow body. According to an embodiment, said hollow body has a longitudinal extension sufficient to keep the respective said first end emerged.

According to an embodiment, said operating unit comprises a wind turbine.

According to an embodiment, an anemometer and a wind vane are provided connected to said electronic device in a wired or remote way.

BRIEF DESCRIPTION OF THE FIGURES

Further characteristics and advantages of the floating structure according to the present invention will become clearer from the following description, shown with reference to the attached figures which illustrate at least one non-limiting embodiment example thereof, in which identical or corresponding parts of said structure are identified by the same reference numbers for convenience. In particular:

- Figure 1 is a schematic perspective view, with parts not shown for clarity, of a first preferred embodiment of a floating structure according to the present invention implemented;

Figure 2 is a three-dimensional view of a first embodiment of a detail extracted from Figure 1;

- Figure 3 is a second preferred embodiment of Figure 1;

- Figure 4 is a third preferred embodiment of Figure 1;

- Figure 5 is a fourth preferred embodiment of Figure 1;

- Figure 6 is a variation of Figure 1;

- Figure 7 is a fifth preferred embodiment of Figure 1;

- Figure 8 is a sixth preferred embodiment of Figure 1; and - Figures 9 and 10 are three-dimensional views of details extracted from Figures 7 and 8.

DETAILED DESCRIPTION OF THE PRESENT INVENTION Before describing the preferred embodiments of the present description in detail, it is considered useful to specify that the scope of the present invention is not limited to the particular embodiments described in the following. The disclosure and description of the present text are illustrative and explanatory of one or more currently preferred embodiments and variations, and it will be clear, to those skilled in the art, that various changes in design, organization, order of operation, operating members, in the structures and position of the equipment, in the methodology and use of mechanical equivalent means can be made without thereby being extraneous to the spirit of the invention.

Furthermore, it is to be understood that the accompanying figures are intended to clearly illustrate and disclose embodiments currently preferred to one of the experts skilled in the art, but do not illustrate how said embodiments should be performed in reality or actual representations of final products; on the contrary, said figures may comprise simplified conceptual views to facilitate understanding or to allow an easier and faster explanation to be provided. Furthermore, the respective dimensions and arrangement of the components may differ from those shown and still function in the spirit of the invention.

On the other hand, it will be understood that various directions such as "lower", "upper", "left", "right", "front", "rear" and so on are performed only with respect to the explanation in combination with the figures and that the components can be oriented differently, for example during transport and production, as well as during operation. Since many different and distinct embodiments can be made within the concepts imparted herein, and since there are many changes that can be made to the embodiments described below, it is to be understood that the details given in the following are to be interpreted as illustrative and not limitative of the spirit of the invention.

In Figure 1, 1 denotes as a whole a floating structure 1 provided with a hollow body 10 which is elongated according to a longitudinal axis D. The hollow body 10 is delimited at the top by a first end 12, which, in turn, carries/is delimited at the top by a base 121 which is prearranged to support an operating unit 20, for example, but not limited, a wind turbine ET. Said turbine is schematized in the attached figures where it presents, in turn, a respective tower T which rests on the base 121 and extends vertically along the axis D, to keep the respective generator with its own axis substantially horizontal. The hollow body 10, moreover, is provided, in the lower part, with a second end 14 prearranged to operate submerged and support at least three, preferably floating, arms 102, which are hinged radially in the second end 14 of the body 10 by means of hinges 202, therefore inclinable at will with respect to the longitudinal axis D. In Figure 1 the arms 102 are substantially identical and evenly distributed around the axis D, so that each arm 102 is separated from the two adjacent arms by 120°. The first end 12 of the hollow body 10 has a coupling point 120 for each arm 102, the function of which will be better explained in the following.

It should be noted that the extension and the transversal dimension of the hollow body 10, therefore its internal volume, is sized taking into account the mass of the structure 1 and what must be supported by the base 121 in order to guarantee that the first end 12 maintains the same base 121 totally emerged, and thus the operating unit 20 associated with the same.

Again, with reference to Figure 1, the structure 1 comprises anchorage means 40 suitable for keeping the hollow body 10 fixed to the ground F in a stable manner. In this regard, the anchorage means 40 comprises a plurality of anchoring members 42 hooked to the seabed F, where each anchoring member 42 is coupled to the free end 1020 of each arm 102 by means of a connection member 44. Each connection member 44 is formed by a flexible member, such as a steel cable, possibly provided with a plurality of strands or a plurality of cables, or by a rigid tubular body without thereby limiting the scope of the present invention. The connection members 44 have the same original length with zero load.

Considering that the hollow body 10 is floating, Archimedes' thrust constantly pushes the structure 1 upwards, in addition to all that it supports, stressing each connection member 44 only in traction, a tension of a type that is absolutely compatible with the mechanics of the flexible members which under traction are substantially rectilinear, if the minimum curvature determined by the longitudinal distribution of the respective mass per unit of length is neglected, and therefore equivalent to tubular bodies under given operating conditions. Therefore, the use of any flexible organ is, for the type of use, a technical equivalent of the use of a tubular body.

Furthermore, the structure 1 comprises means 100 for adjusting the distance between each first end 12 and the respective anchoring member 42, the purpose of which is to vary, according to necessity, the inclination of the longitudinal axis D of the hollow body 10, and therefore the absolute orientation of the operative unit 20, therefore in the case in question, of the tower T of the wind turbine ET with respect to the ground F.

The adjustment members 100 comprise a traction device 50 for each arm 102 arranged between the coupling point 120 and a free end 1020, where each traction device 50 comprises a first body 52 made of flexible material and directly connected to one of the two and to the other by means of a first linear actuator 70. For this reason, by means of the first linear actuator 70 it is possible to adjust a distance between the coupling point 120 and, precisely, the free end 1020, therefore the width of the first angles a, a', a'' and, thus, adjust the position of the base 121 according to necessity. Only for the sake of design economy it was decided to represent only one of the possible configurations in Figure 1, in which the first linear actuators 70 are connected to the coupling points 120 and the traction devices 50 are connected directly to the free ends 1020 of the arms 102. In reality, the first actuators 70 can be inserted in any point of the traction device 50. Naturally, each first actuator 70 can be equipped with sensors for the detection of static and dynamic parameters, in order to know, moment by moment, the state of operation, and the total longitudinal extension. Furthermore, the base 121 carries a power supply device 105 hydraulically connected to each first actuator 70. The function of said device, which, if necessary, could also be placed elsewhere on the structure 1 or even outside of the same, is to power each first actuator 70 to adjust the position of the respective arm 102 (each respective first angle a, a', a'') according to necessity.

With particular reference to Figures 1 and 2, the structure 1 comprises an electronic device 30, hereinafter more briefly indicated with one of the following terms "electronic control unit 30", "unit 30 for controlling" or more briefly "control unit 30", provided with a memory unit 31 and a data processing unit 31', carried by the base 121, as well as at least one inclination sensor 32, 32', 32'' (shown in figure in number of three places at 120°) placed on the base 121, without thereby limiting the scope of the present invention. For example, but not limited to, the electronic control unit 30 and the inclination sensors 32, 32' and 32'' can be located in any other significant point of the structure 1, including the operating unit 20 or the arms 102. Said inclination sensors 32, 32', 32’’ are adapted to detect and transmit to the control unit 30 data relating to the inclination of the bodies to which they are coupled, therefore in the case in question the base 121. The data processing unit 31' sets the control unit 30 in the condition of calculating any corrective actions to be applied and communicating the same, wired or wirelessly, to the power supply device 105 so as to activate each linear actuator 70 to adjust its total extension according to necessity, therefore, the width of each first angle a, a', a'' in order to constantly keep the orientation of the base 121 under control. Naturally, in the application in question, the aim is to contain the deviations as much as possible from the horizontal position of the base 121.

The control unit 30 is interfaced with a digital anemometer A and a digital wind vane B installed on board of the structure 1 or of the operating unit 20 as long as it is directly hit by the wind, and electronically connected with the control unit 30 to maximize its ability to adjust the positioning of the base 12 to the external conditions and to optimize the efficiency of the wind turbine.

For economy of design in the attached figures the hydraulic connections between linear actuators and digital devices described above and others that could be described in the following have not been shown, except in cases of elementary representability.

The use of the floating structure 1 is easily understood from what is described above and does not require further explanation. On the other hand, it may be useful to specify that each traction device 50 of the adjustment members 100 allows to adjust the distance between each first end 12 and the respective anchoring member 42 by adjusting the distance between the free end 1020 of each arm 102 and the corresponding coupling point 120.

As described above, it should be noted that each arm 102 is mechanically equivalent to a connecting rod of an articulated quadrilateral in which the connection members 44 are the rocker arms suited to rotate on substantially parallel planes, and the corresponding anchoring members 42, fixed to the ground, form the frame.

Finally, it is clear that modifications and variations can be made to the floating structure 1 described and illustrated here without thereby departing from the scope of the present invention.

For example, Figure 3 shows a variation of the structure 1 in which each traction device 50 comprises a first lever 522, hinged to the coupling point 120 of the hollow body 10 transversally to the axis D, and a second lever 524 hinged to the free end 1020 transversally to the respective arm 102. Each first lever 522 is hinged to a respective second lever 524 by means of a kinematic pair 526 having an axis transversal to the longitudinal axis D. Furthermore, for each traction device 50 a second linear actuator 72 is provided which is coupled to the hollow body 10 in the second end 14 as well as being coupled in a hinge-like manner to one of said first lever 522 or said second lever 524.

Each second actuator 72 is hydraulically connected to the feeding device 105 and is equipped to be operable in a dynamically and statically controllable manner; for this reason, every second actuator 72 is connected to the control unit 30, arranged to operate the latter according to necessity.

In particular, in Figure 3, each second linear actuator 72 is coupled in a hinge-like manner to the respective first lever 522 and second lever 524 coaxially with the kinematic pair 526. Alternatively, the hinge-like connection of each said second linear actuator 72 could also be located at any point along one of said first lever 522 or second lever 524. It is well understood that said configuration is functionally identical to a version in which the second linear actuator 72 and, optionally, one of the first levers 522 or one of the second levers 524, have changed places. Said versions have not been illustrated for design economy, since the explanation given above is clear enough to allow full understanding.

Figure 4 illustrates a further embodiment of the structure 1 object of the present invention, also provided with three arms 102 arranged at 120°. As can be seen in this figure, each traction device 50 comprises a hoist 525 provided with a first multiple block 5250 and a second multiple block 5251, connected together by a cable 5271 and carried, respectively, by a coupling point 120E and by a free end 1020 of an arm 102. The base 121 carries a device 73 for adjusting the length of the cables 5271, the purpose of which is to adjust the distance between each coupling point 120 and, precisely, the respective free end 1020, therefore the width of the first angles a, a', a'', always with the active control of the sensors 32, 32' and 32’’. For this reason, the adjustment device 73 for the length of the cables 5271 is electronically connected to the control unit 30 for the activation thereof.

With reference to Figure 5, a further variation of the structure 1 is shown, in which only two arms 102 are provided. Each arm 102 corresponds to a traction device 50 and to an anchoring member 42. Each anchoring member 42 is connected to the free end 1020 of an arm 102 by means of a connection member 44. A further anchoring member 42 is constrained to the lower part 14 of the hollow body 10 by means of a further connection member 44, so that the structure 1 is always hooked to three points of the seabed F. Also in this case the connection members 44 have the same length.

Figure 6 shows a further embodiment of the present invention, which is a variation of Figure 1. In this case, each connection member 44 is connected to the free end 1020 of an arm 102 by means of a tubular body 45, whose function is to limit the extension of the cable necessary to construct the connection member 44. On the other hand, in practice, the tubular element 45 can be replaced by any functionally equivalent mechanical member. In this case, without limiting the scope of the present invention, the three anchoring members have been replaced by a circular base 42', which is more suitable for sandy bottoms.

In Figure 7, 1 denotes, as a whole, a variation of the structure 1 in which the arms 102 are radial and rigidly connected to the second end 14 of the hollow body 10, therefore transversal to the longitudinal axis D. Furthermore, the arms 102 are substantially identical and angled one relative to the other by an angle b (not shown in Figure 7) comprised within a range of 60° - 150°. Again, with reference to Figure 7, the free end 1020 of each arm 102 carries a floating cylindrical body 104. In this case, the anchorage means 40 comprises a connection member 44 arranged between each anchoring member 42 and a lower end 1040 of each cylindrical body 104 by means of the interposition of a known joint not illustrated.

It should be noted that each connection member 44 is actuated by a tubular body with a rectilinear axis and that all the connection members 44 of this embodiment of the structure 1 have the same longitudinal extension. However, for what has been said with reference to the application of Archimedes' principle, the same function performed by the tubular bodies used to form the connection members 44 of said version of the structure 1 could be performed by flexible members of the type described above with reference to Figures 1-6 without changing the performance of structure 1 during use.

The anchorage means 40 comprises a further tubular connection member 44 which connects the lower end 1041 of the lower portion 14 with a further anchoring member 42. According to this embodiment of the structure 1, the adjustment members 100 comprise a third linear actuator 101 for each anchoring member 42. Each third linear actuator 101 has an armature 107 coupled in a hinge-like manner to a connection member 44, by way of an articulation element 110, and a tubular stem 108 coupled to an anchoring member 42 by means of a joint 111. The adjustment members 100 comprise a platform 103 which integrally connects the armatures 107.

Each anchoring member 42 comprises a flat plate 109, better shown in Figures 9 and 10, for fixing to the ground which carries the joint 111 at the top.

In particular, in Figure 9 the same plate 109 carries a plurality of pegs 114 connected to it on the side of a respective lower face. Said pegs 114 are parallel and transversal to the plate 109.

Figure 10 shows a variation embodiment of the plate 109 which carries at the bottom a hollow tubular body 112 which extends transversally to the plate 109 itself.

Again, with reference to Figure 7, the platform 103 preferably but not limitedly supports the control unit 30 connected to the sensors 32, 32', 32'' and the power supply device 105 which, in this embodiment, is hydraulically connected to each third linear actuator and to the control unit 30 for the respective actuation.

In this case, the adjustment of the position of the base 121 is always carried out on the basis of the information on the orientation of the base 121 detected by the inclination sensors 32, 32', 32'', information which will be processed by the control unit 30 which, in turn, will act on the global longitudinal extension of the third linear actuators 101. Each of these actuators acts on a respective connection member 44 causing a variation in the inclination of the hollow body 10 and therefore of the base 121 and, ultimately, of the operating unit 20, which comprises the wind turbine ET. The adequate programming of the control unit 30 will allow to always keep the base 121 and the wind turbine ET oriented according to the optimal specifications provided by the manufacturer. Naturally, as the configuration of each third linear actuator 101 varies, the platform 103 will consequently change its orientation with respect to the ground F.

On the other hand, it may be useful to specify that each third linear actuator 101 can be, if deemed useful, electrically or pneumatically powered without thereby changing the scope of the present invention.

Figure 8 finally shows a further variation of the present invention, in which the third actuators 101 are housed inside the floating cylindrical bodies 104 and inside the second end of the hollow body 10 and therefore are adapted to level the base 121 directly, without the intermediation of the connection members 44.

On the other hand, considering that the longitudinal extension of the tubular bodies with which the connection members 44 of the versions of the structure shown in Figures 7 and 8 are formed, it should be noted that each arm 102 is mechanically equivalent to the connecting rod of a quadrilateral in which the tubular bodies 44 are the rocker arms adapted to rotate on substantially parallel planes, and the corresponding anchoring members 42, fixed to the ground, form the frame of said articulated quadrilateral. The connecting rods of the two articulated quadrilaterals, or the two arms 102, are rigidly connected by means of the hollow body 10. The extension of the tubular bodies 44 can be even a few hundred meters. Due to the particular arrangement of the hinge-like hooking of the tubular bodies 44 to the anchoring members 42, and therefore to the ground, in particular at the vertices of a polygon having at least three sides, it is evident that the movement of the corresponding base 121 will actually be similar to that of a connecting rod of an articulated quadrilateral, but only in the range of very few fractions of a degree. On the other hand, this will in any case be sufficient to guarantee that the base 121 remains substantially parallel to itself under the control of the control unit 30 even in prohibitive conditions for the structure 1, with strong winds and rough seas and that it is possible to maintain the tower T of the wind turbine ET with a minimum verticality defect that does not affect the operation of the respective generator.

It should be noted that, in the case of a triangular arrangement of the anchoring members 42, the triangle at the vertices of which the anchoring members 42 are placed can also intentionally have slightly larger dimensions than the triangle formed by the upper coupling points 1040, while remaining said triangles similar one the other. This is valid for every constructive embodiment of the present invention and allows to obtain further advantages on the electrical efficiency of the generator.

On the basis of what is described above, it is easy to understand that all the versions of the structure 1 solve the problem of making a floating structure capable of maintaining a geographically determined position (by the ground connection cables) with the respective mobile platform according to the combination of the motions of articulated parallelograms which have respective connecting rods (the arms of the structure) rigidly connected to each other, as in Figure 1, or angularly movable with respect to a common reference formed by the hollow body 10 to face the different marine and atmospheric conditions, is currently solved both with two or three-arm structures, provided that the tie rods that connect the structure to the ground have a constant extension. This allows the respective base to move parallel to itself, as does the operating unit supported by the same. This is particularly useful when the operating unit 20 comprises the tower of a wind turbine which, notoriously, must be kept with the blades substantially transversal to the free water surface in which the structure 1 is partially submerged, therefore in the optimal conditions for producing electricity, even in conditions of very strong winds and, therefore, of particularly high waves.

Claims

1. A floating structure (1) provided with a hollow body (10) which is elongated according to a longitudinal axis (D), is provided with a first end (12) delimited at the top by a base (121) prearranged to support an operating unit (20)(ET) and is delimited, on the side opposite to said first end (12), by a second end (14) prearranged to operate submerged; said second end (14) supporting at least two arms (102); anchorage means (40) being associated with said hollow body (10) to fix it to the ground (F); said anchorage means (40) comprising an anchoring member (42) for each said arm and a connection member (44) arranged between each said anchoring member (42) and a respective said arm (102); means (100) for adjusting the distance, being arranged between said first end (12) and each said anchoring member (42) in order to vary the inclination of the hollow body (10) with respect to the ground (F); characterised in that each said arm (102) is hinged to said hollow body (10) in said second end (14); each said arm (102) having a respective free end (1020); said adjustment means (100) comprising a traction device (50) having an adjustable length for each said arm (102), wherein each said traction device (50) is arranged between said first end (12) and one said free end (1020) to define, according to the need, a first angle width (a) between said arm (102) and said hollow body (10).

2. The structure according to claim 1, characterised in that said connection members (44) have the same longitudinal extension; at least one said connection member (44) comprising a tubular body or a flexible member comprising a cable or several cables.

3. The structure according to claim 1 or 2, characterised in that it comprises an electronic device (30) provided with a memory unit (31) and a calculation unit (31') electronically connected to one another; at least one inclination sensor (32) being associated with said hollow body (10) and electronically connected to said electronic device (30) in a wired or remote manner in order to measure deviations of a current position of said base (121) with respect to a given reference position stored by said memory unit (31).

4. The structure according to claim 1, characterised in that each said traction device (50) comprises a first body (52) made of a flexible material connected to said second end (14) or to one said free end (1020) through the interposition of a first linear actuator (70) electronically connected to said electronic device (30), in a wired or remote manner and hydraulically sealed, to a second hydraulic supply device (105) carried by said base (121); said first linear actuator (70) being equipped to transmit, in use, information regarding its own operating conditions to said electronic device (30).

5. The structure according to claim 1, characterised in that each said traction device (50) comprises a hoist (35) provided with a first and a second relay member (525) (5250)(5251) connected respectively to said first end and to one said free end (1020) of a said arm (102).

6. The structure according to claim 1, characterised in that each said traction device (50) comprises a first lever (522) hinged to said first end (12) transversally to said longitudinal axis (D) and a second lever (524) hinged to said free end (1020) transversally with respect to said arm (102).

7. The structure according to claim 6, characterised in that said first lever (522) and said second lever (524) are hinged together by a kinematic pair (526) having an axis transversal to said longitudinal axis (D); a second linear actuator (72) electronically connected to said electronic device (30) being coupled to said hollow body (10) in said second end (14) as well as to at least one of said first lever (522) and said second lever (524); said second linear actuator (72) being equipped to transmit, in use, information regarding its own operating conditions to said electronic device (30).

8. The structure according to claim 7, characterised in that said second linear actuator (72) is coupled to said first lever (522) and to said second lever (524) concentrically to said kinematic pair (526).

9. The structure according to any one of the claims from 1 to 8, characterised in that at least one said connection member (44) is connected to the respective said arm (102), through one said free end (1020).

10. The structure according to any one of the claims from 1 to 9, characterised in that said arms (102) are substantially identical to one another and distributed evenly around said axis (D).

11. The structure according to claim 10, characterised in that said arms (102) are three in number and distributed evenly with respect to said hollow body (10).

12. The structure according to claim 10, characterised in that said arms (102) are two in number and said second determined angle (b) has a width comprised within a range of 60°- 150°.

13. The structure according to claim 12, characterised in that a further said connection member (44) is connected to said hollow body (10) in said second end (14).