WO2018065655A1

WO2018065655A1 - Rigid pedestal of a wind tower

Info

Publication number: WO2018065655A1
Application number: PCT/ES2017/070655
Authority: WO
Inventors: Juan Francisco DE LA TORRE CALVO
Original assignee: Deltacore Estudios Y Proyectos, S.L.
Priority date: 2016-10-06
Filing date: 2017-10-06
Publication date: 2018-04-12
Also published as: ES2662926B1; ES2662926A1

Abstract

The invention relates to a pedestal (1) of a wind tower, which is installed between a foundation and a previously designed wind tower to increase the height of said tower without varying the design thereof. Said pedestal comprises an optional shaft (2) comprising a plurality of horizontal structural elements (3) made of pre-tensioned reinforced concrete and connected to each other forming horizontal divisions, and dynamic modulators (6) made of pre-tensioned or post-tensioned concrete and connected by one end to the upper base surface (4) or to a horizontal structural element (3) of the shaft, and by the other end to the lower base surface (5) or to the foundation.

Description

RIGID PEDESTAL OF WIND TOWER D E S C R I P C I Ó N

OBJECT OF THE INVENTION

The present invention relates to a rigid wind tower pedestal that allows raising the starting height, and thereby the coronation height, of the wind tower that is installed on it without the need to make modifications to the design of said wind tower.

The foundation of the invention is to be able to take advantage of the existing technology of the wind turbine towers by applying it at heights higher than those towers themselves cannot reach, but without altering the design of the tower or the operating regime of the wind turbine .

This supposes an extension of the field of exploitation of the existing technology and allows to increase its use without the need to design new models of wind towers. That is to say, the proposed pedestal is universal and is capable of supplying what is necessary for the existing technology to remain valid at levels higher than those that until now have been the maximum of exploitation.

BACKGROUND OF THE INVENTION

Currently there are on the market towers for wind turbines of steel, and reinforced concrete, and a mixed hybrid version of steel and concrete. Each type has its advantages and disadvantages. In all cases, manufacturing, transportation and assembly possibilities impose clear limits on operating heights.

Steel towers are manufactured for heights between 80 and 100 m, as they are the most competitive in that range of heights. These towers can be hollow cylindrical or conical, like lattice bars. However, for higher heights the use of steel is impossible since the thickness dimensions of the steel needed to support more height raise the cost greatly. On the other hand, if you resort to Increases in the base diameter, the necessary dimensions make transportation from the factory to the wind farm unfeasible, due to the width dimensions of the tracks and the overpass roads. Therefore, it is not possible with this model to resort to higher operating heights economically. The advantage of steel wind towers is that it is a versatile, industrialized and efficient technology. Furthermore, this technology has been used for years and there is a wide and valuable technical development contrasted by thousands of installed towers.

As described previously, the technical problem of this solution is that it cannot be applied at great heights in itself, due to the insurmountable technological limit of steel referred to the dimensions of the pieces of said material. On the other hand there are concrete towers, which in no way benefit from technology linked to steel, and require a totally ad hoc technology, even if they can reach heights greater than steel. They also have the disadvantage that their designs must be specific for each wind turbine, canceling any possibility of universality of the solution. The main drawback of these towers lies in their execution, especially in the realization of divisions between sections. In addition, they are expensive to run and assemble, so much so that, despite being able to reach higher heights, they have not replaced steel ones. And so, the need to assemble in many pieces, of high weight, the enormous amount of divisions to be finished off in situ and the enormous amount of auxiliary means necessary for assembly - especially in the form of cranes - make them complex construction, laborious, slow and expensive.

Nor are they exempt from maintenance, although not so much for the environmental aggression as for the review and control of the correct behavior of the divisions between pieces. All this justifies that they are used basically in the range of heights inaccessible for steel solutions, that is, from about 100 m high.

Hybrid towers are an intermediate option that remains a viable alternative for great heights. These solutions are not versatile as they remain designs. specific for each wind turbine. They also require combining the construction of steel elements with concrete, making assembly difficult, and also requires a special technology that does not fully nourish either steel or concrete. The steel part of these wind turbines is completely new, it does not use designs already made.

It is a poorly developed technology that has no signs of being the best solution for high-rise towers or with any wind turbines. To the problems of execution of the concrete part is added that the current development of steel is not directly applicable to this type of solution. They require a completely new load calculation because the dynamic behavior of the hybrid tower is different from that of the currently developed steel towers.

It also requires, on the one hand the design, calculation and certification of the concrete part, and on the other hand the design, calculation and certification of the steel sections. That is, they require the calculation of two new towers, a first part of concrete and the remaining part of completely new steel that does not take advantage of previous developments.

In the current state of the art several groups of inventions can be distinguished:

Thus, for example, patent ES-2524840 B1 refers to a foundation for towers, which is necessarily buried or partially buried, and which includes a completely buried flat slab. The soil in which the foundation is buried acts as a ballast to optimize the amount of material used in the foundation of large towers and high loads. It is intended to reduce the foundation costs of this type of towers.

Another group of inventions are those in which the shaft of the tower has lateral reinforcements up to a certain height. These are wind towers that have to be fully developed, including reinforcements, and are presented as an alternative to the wind towers currently developed. The reinforcement elements that are added to these shafts only allow to improve the resistant behavior of the shaft but do not allow to adapt the system's own frequency. Among these types of solutions, for example, patent EP-2444663 A2 is known, which refers to a wind turbine configured to be installed on land and which is composed of a wind turbine gondola mounted on a tower. The patent includes the gondola and a complete tower reinforced with leg-like elements.

JP2002122066 A describes a complete tower that connects to the foundation at its bottom and to the gondola at its top. Said complete tower is composed of cylindrical hollow concrete rings with T-shaped reinforcement elements that connect between the tower and the foundation.

A third group of current inventions refers to elements that are arranged in the lower part of a tower, such as those described in patent ES2369304 B2, in which a reinforcement base for wind tower shafts is presented. In this invention the shaft of the tower to be reinforced is directly attached to the foundation and the reinforcing elements are attached directly to the tower's shaft. This fact means that a modification of the original shaft of the tower must be made, thus canceling the calculation and design previously performed.

On the other hand, patent ES2438626 B1 refers to a support structure for wind turbines and mold for obtaining such structures. The structure is made without horizontal divisions between panels all of them equal in height to the total height of said support structure. The resulting structure has a truncated conical or truncated pyramid geometry. It requires a transition piece of mixed steel-concrete composition.

US patent application US2016 / 0215761 refers to a wind turbine tower, formed by two sections, a lower one consisting of concrete sections superimposed on each other and held by transition pieces from one piece to its immediately adjacent top and above which a section of superimposed steel pieces is installed, it being necessary to fasten the sections of the lower concrete section to the base, holding such braces in the transition pieces that join the pieces that make up the lower section of the wind tower. These braces have the mission of maintaining the integrity of the tower by exclusively reducing the bending moments in the concrete shaft, they are not designed to adjust the behavior dynamic tower but to optimize the structural design of the central concrete shaft. The patent does not raise at any point the possibility that the central shaft is not a resistant element. The braces are described as metallic elements and expressly cites that the solution eliminates the posts of the structure. This point cannot be met with wind towers if the central shaft is structural because the decompression hypotheses required by the design codes are not ensured.

Finally, the invention does not contemplate using the existing metal towers but instead opts for a complete tower design, even of the metal sections that rest on the concrete. It should be noted that although the inventor wanted to have a metal tower already designed on the concrete part, the system would not ensure the dynamic design conditions and therefore would require recalculation of the dynamic loads and the validity of the metal sections. Finally, it should be said that none of the current solutions is universal nor does it maintain the natural frequency of the system, so it is the purpose of the invention to seek a solution that maintains the natural frequency of the system.

DESCRIPTION OF THE INVENTION

The present invention presents a rigid wind tower pedestal that allows to increase the working height of the current metal wind towers without modifying its design, since this rigid structure of the pedestal reduces the bending moments in the concrete shaft, so the wind tower that is located superior to the shaft, without modifying its traditional design, since the shaft acts as a stable surface on which it sits.

Stiffness is a qualitative measure of the resistance to elastic deformations produced by a material, which contemplates the ability of a structural element to withstand stresses without acquiring large deformations. The stiffness coefficients are physical quantities that quantify the stiffness of a resistant element under various load configurations. Normally the rigidities are calculated as the ratio between an applied force and the displacement obtained by the application of that force. When we talk about a rigid pedestal we must understand that it is barely deforms before the application of forces in it. These deformations are evidently much less equal to the chosen tower and materials used than a cable-stayed solution such as those usually used. The pedestal is installed between a foundation (or an increase in it) and the wind tower.

That is, the wind tower does not join the foundation directly as in the state of the art but joins the pedestal. In addition, the proposed pedestal is completely above the ground since at no time it acts as a foundation and therefore is not buried or partially buried.

An essential advantage of the present invention is that the pedestal allows to raise the height of coronation of the wind tower while maintaining the dynamic behavior of said invariable wind tower against the dynamic loads introduced by the turbine. That is, the height of the pedestal serves entirely as an increase in the total height of the tower.

Thus, it is a rigid wind tower pedestal that is universal and allows the use of currently known structural systems. The pedestal can be adapted to any wind tower regardless of its geometry and dimensions. It also allows the correct adaptation to the operating regime of any wind turbine currently known.

Other advantages of the present invention are:

- allows a perfect adaptation to conventional foundation systems,

- allows to increase the operating height without altering the technology of existing towers, and

- It is easy to produce since it is manufactured from horizontal structural elements and dynamic modulators obtainable with molds that are simple and easy to assemble. Also, the pedestal has great geometric and mechanical versatility to allow any increase in height in any type of wind tower with which it will be installed. Another advantage associated with the proposed pedestal is that the maintenance cost is very low. The pedestal is configured to be installed on a foundation and receive an already designed wind tower, as previously described, without the need to modify its design. It is made of reinforced and post-tensioned concrete and optionally comprises at least one shaft that comprises a plurality of horizontal structural elements joined together, although said shaft and a plurality of prestressed or post-tensioned dynamic modulators that can support the already designed wind tower can be avoided and adjusted the dynamic characteristics of the system, specifically the frequency of the system, so that loads do not vary.

These dynamic modulators, if the structural shaft is avoided, would collect 100% of the wind tower load and maintain the system frequency, although a pedestal with a central structural concrete shaft associated with the dynamic modulators could be used. Once the modulators were mounted, the system would be post-tensioned.

Post-tensioning cables, which include dynamic modulators, can be anchored at one end directly to the shaft or the wind tower and at the other end can be anchored to the bottom base surface of the shaft or to the foundation. For dynamic modulators the thickness measurements, the angle of inclination of the reinforcement cables inside, the height and length also depend on the tower to be installed on the pedestal.

The system of dynamic modulators in conjunction with the strength and tracing of the testing of the reinforcement cables makes it possible to adapt the frequency of the whole to any wind tower that you want to install on the pedestal, without altering its operating regime. This makes the pedestal totally versatile and can be used in conjunction with any wind tower already designed in the state of the art.

In an exemplary embodiment, the pedestal also comprises an outer platform that can be permanent or removable and which is preferably a perimeter steel platform. It is designed to allow operators access to the connection area between the steel tower and the pedestal to perform the relevant actions to carry out this connection and its maintenance. Also, in an exemplary embodiment, the shaft (or one of the lower cylinders thereof if it is formed by the union of cylinders) has a pedestal access door. On the other hand, the chump allows the passage of people, materials, equipment and lifting means between the pedestal and the steel tower.

Preferably the prestressed or post-tensioned dynamic modulators extend from the upper base surface of the pedestal shaft and not from an intermediate area of said shaft. However, in an exemplary embodiment, the shaft comprises at least one horizontal structural deflection element. This element is configured to allow the deviation of the path of the reinforcement cables that extend in the vertical direction through the shaft and that follow an inclined path in the dynamic modulators.

In the horizontal structural element of deviation there may be a curved deviation of the cable routing or a straight anchor of a reinforcement cable that runs through the dynamic modulator until it is anchored on the surface of the bottom base of the shaft or in the foundation to which it is joins the pedestal, and a straight anchor of the vertical tesado from the upper base surface of the shaft with high strength bars. In the exemplary embodiment in which the prestressed or post-tensioned dynamic modulators are attached to a horizontal structural element of the shaft that does not correspond to the upper base surface, there are always post-tensioned reinforcing cables that extend vertically from the base surface upper (at the junction with the tower) to the horizontal structural element to which the dynamic modulators are attached. This condition is necessary for the correct transfer of the dynamic forces of the metallic wind tower through the pedestal. That is, it is essential that the shaft is compressed between the tower connection and the start of the reinforcement cables in the foundation. This is why in the described pedestal the post-tensioning starts above or at the level of the tower connection, as previously explained. In this way the non-decompression condition is met under hypotheses dictated by calculation code.

The horizontal structural elements that make up the shaft, as well as the element Structural horizontal deviation, can be solid, hollow elements or with internal radial reinforcements to stiffen the section.

In the exemplary embodiment in which the dynamic modulators are attached to the bottom base surface of the shaft, this connection is made by means of lower anchors, which can be, for example, delta wedges. Said wedges are arranged on the lower base surface and dynamic modulators are supported therein. The reinforcement cables inside are attached to the lower base surface through the inside of the wedges.

The horizontal structural elements are bonded to each other with dry divisions. In embodiments where it is necessary to reinforce said divisions, the possibility of reinforcing them with mortar is contemplated. These horizontal structural elements, which can be cylindrical or polygonal, are as tall as the crane load allows, minimizing the number of horizontal divisions, limiting their slenderness to forty times their thickness. The key to ensuring dry horizontal divisions are the post-tensioned reinforcement cables that keep them compressed at all times during the life of the pedestal. The pedestal anchors to the tower are also overlapped with the post-tensioning of the pedestal reinforcement cables. Vertical tensions in service remain compression along the entire height of the pedestal. This aspect is necessary to guarantee the good behavior of the system (foundation, pedestal, tower and complete turbine) during the whole useful life before dynamic actions. The rest of the characteristics related to the dynamic behavior of the wind tower are regulated by the dimensioning of the dynamic modulators and the sections of the horizontal structural elements.

The upper base surface of the shaft is thick enough to support the weight of the wind turbine tower. It also has a sufficient radial offset between the anchor zone of the tower and the corresponding reinforcement cable heads (testing cables). Preferably, the design of the upper base of the shaft is carried out to allow the coupling of wind towers in which the inside diameter of the connection is greater than 2 m and the external diameter of the connection is less than 6 m. The dynamic radial modulators are made up of planes, bevels or beams, and are hoisted to their position with the maximum size that the cranes allow by weight, also minimizing the number of horizontal divisions.

Post-tensioning is determined, both in plot and in force, based on the wind tower to be installed. To do this, a compression is necessary in the horizontal divisions of the pedestal so that it is ensured that they are never opened by decompression in service.

In addition to this, the entire system of walkways, stairs and other elements necessary for the transit and assembly and maintenance operations of the operators is available internally.

The fundamental characteristic of the invention is that the combination of the dimensions of each element together with the strength and stiffness of the post-tensioning, which allows the joint dynamic behavior of the tower with the pedestal, with the foundation and with the turbine to present the same dynamic regime as the complete wind turbine of lower existing height (foundation, more tower, more turbine). This is an indispensable characteristic to be able to use the wind towers already known without having to modify their design.

Thus, it is achieved that the steel wind towers already developed can reach higher operating heights without the need for alterations in the manufacturing and operation regime of the wind turbine. In this way a very high versatility is achieved because with a unique design of current steel wind tower, the entire range of higher heights can be covered and all the technology currently developed and applied to this type of wind towers can continue to be used without alterations.

The design, geometry, materials and active tension state of the pedestal also allows it to be equipped with the mechanical characteristics necessary in each case so that the dynamic behavior regime of the wind turbine installed on it is not altered. That is, the pedestal allows to adapt the frequency of the system to continue using the wind towers developed for lower heights. In summary, the improvements proposed by the present invention can be grouped into: a) Faced with the steel towers of the prior art: the proposed pedestal allows the use of known steel towers without modifications for bushing heights above of 100m. b) In front of the concrete towers: it uses the technological development of the wind towers of lower heights and eliminates the need to perform an additional calculation of loads on the resulting structure. c) On the base reinforcement structures: it allows the use, without modifications, of the wind towers used for lower heights and eliminates the need to perform an additional calculation of loads on the complete structure (tower plus reinforcements).

The measurements of the pedestal are obtained for different technical and functional specifications of each metallic wind tower and according to the geotechnical characteristics of each terrain. The aspects of the dynamic behavior of the system (considering the system as the total set of the foundation, the pedestal, the tower and the complete turbine) that are controlled with the described pedestal are the proper frequency of the fundamental mode of vibration of the whole set, the frequencies of other suitable ways to avoid spurious vibrations of the pedestal itself, and the rotational and translational rigidities at the base of the metal tower attached to the pedestal. The total height of the pedestal is chosen in each case to achieve the desired total height of the wind energy collection system, without modifying the design of the metal tower to which it is to be attached.

DESCRIPTION OF THE DRAWINGS

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical implementation thereof, a set of drawings is attached as an integral part of said description. where illustrative and not limiting, The following has been represented:

Figures 1 a-a- Show perspective, elevation and top floor views of a wind tower pedestal with related and post-tensioned dynamic modulators.

Figures 2 a-a- They show perspective, elevation and top floor views of a wind tower pedestal with disconnected and post-dynamic dynamic modulators with the reinforcement cables embedded in the shaft.

Figures 3 a-a- They show perspective, elevation and top floor views of a wind tower pedestal with disconnected and post-dynamic dynamic modulators with the reinforcement cables arranged inside the shaft, not embedded in it.

Figure 4 a.- Shows a view of an embodiment of a horizontal cylindrical structural element.

Figure 4 b.- Shows a view of another embodiment of a horizontal cylindrical structural element.

Figure 5 a.- Shows a view of an embodiment of a hexagonal horizontal structural element.

Figure 5 b.- Shows a view of another embodiment of a hexagonal horizontal structural element.

Figure 6.- Shows a horizontal division

Figures 7 a-b.- Shows perspective views and section of a horizontal structural element of diversion.

Figures 8 a-b.- Shows perspective views and section of another horizontal deviation structural element.

Figure 9 a.- Shows a view of the union of the wind tower to the upper base surface of the shaft in an exemplary embodiment in which the connection is made inside the wind tower.

Figure 9 b.- Shows a view of the connection of the wind tower to the upper base surface of the shaft in an exemplary embodiment in which the connection is made outside the wind tower.

Figure 10.- Shows a view of the lower anchor PREFERRED EMBODIMENT OF THE INVENTION

Examples of embodiments of the present invention are described below with the aid of Figures 1 to 10.

The rigid wind tower pedestal of the present invention is configured to be installed between a foundation and a metal wind tower already designed without modifying its design. The pedestal (1) is disposed on the ground and is not buried or partially buried in it but arranged on a foundation or an extension of it. The rigid wind tower pedestal of the invention allows to increase the working height of the current metallic wind towers without modifying its design, since this rigid structure of the pedestal reduces the bending moments in the concrete shaft, so that the tower wind is located superior to the shaft, as just said, without changing its traditional design, since the shaft acts as a stable surface, as if it were the foundation on which it sits. Figures 1 a-c, 2 a-c and 3 a-c show some examples of realization of the proposed wind tower pedestal (1). In a preferred embodiment, the pedestal (1) is configured to be used with wind towers with a diameter between 2m and 6m.

It is a pedestal (1) that can be considered universal because, as previously described, it is applicable to different specifications of metal towers without modifying their design and for different types of terrain.

The pedestal (1) comprises at least one shaft (2) comprising a plurality of horizontal structural elements (3) joined together and comprises an upper base surface (4) to which the wind tower is attached and a lower base surface (5) that is attached to the foundation. Likewise, the pedestal (1) comprises pre-tensioned or post-tensioned dynamic modulators (6) extending from the upper base surface (4) or a horizontal structural element (3) of the shaft (2) to the bottom base surface (5) of the shaft or to the foundation to which the pedestal is attached in its final position. In an exemplary embodiment, the pedestal (1) comprises a horizontal structural deflection element (14) which is the element from which the dynamic modulators (6) start.

Said dynamic modulators (6) are configured to adjust the characteristics of the foundation set, the pedestal and the wind tower to the requirements of the already designed wind tower to be installed on the pedestal, without changing the design conditions of the Turbine and metal tower. That is, thanks to the dynamic modulators

(6) The previously described aspects of the dynamic and local behavior of the metallic wind tower are regulated.

An example of embodiment in which the dynamic modulators (6) are connected are shown in Figures 1 a-c. As can be seen in these figures, the dynamic modulators (6) are of the corbel type and are connected to the shaft (2) along its entire height.

In another exemplary embodiment, shown in FIGS. 2 ac, a pedestal (1) is presented with dynamic modulators (6) disjointed in which the reinforcing cables (7) are as can be seen in FIG. 2c, embedded in the horizontal structural elements (3) of the shaft (2).

On the other hand, in Figures 3 a-c the preferred embodiment is shown in which the dynamic modulators (6) are disconnected and the reinforcement cables (7) are arranged inside the shaft (2). In this case the reinforcement cables (7) are not embedded in the shaft itself (2) as in the previous example.

The pedestal (1) is reinforced and post-tensioned concrete and therefore inside the shaft (2) and inside the dynamic modulators (6) are reinforcement cables (7) that are testing cables with which the transmission of loads from the wind tower to the ground is controlled. Thanks to this transfer of efforts it is possible to increase the height of the wind turbines without having to resize their resistance to loads or the rest of their measurements.

In an exemplary embodiment, the upper base surface (4), which is on which the wind tower is installed, has a determined thickness, sufficient to allow the fixing of a reinforcing cable (7) that crosses at least said upper base surface (4) and a dynamic modulator (6).

Preferably the radius and thickness of the shaft (2) are constant and depend on the measurements of the wind tower to be installed on the pedestal (1). The horizontal structural elements (3) that form the shaft (2) are arranged stacked together, forming horizontal and non-vertical divisions (9). In addition, said divisions (9) are preferably performed dry by means of bone or "dog's mouth" joints. The coupling of the horizontal structural elements (3) with each other is ensured by the post-tensioning of the reinforcement cables (7) of the pedestal.

The horizontal structural elements (3) can have a cylindrical configuration or have polygonal sections so that the outer face of the horizontal structural element (3) is shaped. This embodiment in which the horizontal structural elements (3) have flat faces makes it easier to adjust the dynamic modulators (6).

Figure 6 shows a horizontal division (9) that is the area of union between horizontal structural elements (3) of the shaft. The division (9) is designed to serve as a barrier to the entry of water from the outside of the pedestal (1), to function as a shear key between the horizontal structural elements (3), and to, in an emergency, be able to execute wet joint It is a joint with trough breast and internal inclined pour cannulas for injection of the filling mortar. In this case the upper face (10) of each horizontal structural element (3) comprises at least one recess (12) and the lower face (11) comprises a shoulder (13). In an exemplary embodiment, these are recesses (12) and projections (13) that extend along the entire section and in all cases the recesses (12) and the projections (13) are complementary. Thus, when a horizontal structural element (3) is placed on an equal horizontal structural element (3), the at least one shoulder (13) of the lower face (11) is housed in the at least one recess (12) of the upper face (10). This type of divisions (9) for dry joints are also applicable to the horizontal division between the horizontal structural deviation element (14) and the horizontal structural element (3) of the shaft to which it is attached in the embodiments in the that the shaft comprises said horizontal deflection structural element. In the exemplary embodiment in which the shaft (2) comprises at least one horizontal deflection structural element (14), it is arranged in contact with at least one of the horizontal structural elements (3) of the shaft (2). In the event that the dynamic modulators (6) do not extend to the upper base surface (4), they extend to said horizontal structural diverting element (14) in which the change of trajectory of the reinforcement cable (of trajectory) is made vertical from the upper base surface (4) to the horizontal deflection structural element (14) with an inclined path along the dynamic modulator (6).

As can be seen in figures 7 ab and 8 ab, the change of trajectory of the reinforcement cables (7) can be carried out directly inside the horizontal bypass structural element (14) (or the upper base surface (4) if The dynamic modulator (6) extends directly from it) or the same effect can be obtained using two reinforcing cables (7). In this second example, one of the reinforcing cables (7) extends vertically between the upper base surface (4), to which it is anchored, and the horizontal structural deflection element (14), to which it is anchored, and Another part cable extends the horizontal structural deflection element (14), to which it is anchored, with the corresponding inclination through the dynamic modulator (6).

For high-rise pedestals, the preferred option will be the reinforcement cable continuous (represented in figure 7a) because the bankruptcy angle is light. For small pedestals, the solution of several reinforcement cables (7) connected to the horizontal bypass structural element (14) (shown in Figure 7a) will preferably be carried out.

Figures 9a and 9b represent two alternatives to the connection between metallic wind tower (8) and pedestal (1). In the embodiment of figure 9 a, the reinforcement cables (7) of the pedestal (1) go inside the section of the wind tower (8), and in the embodiment of figure 9b, the reinforcement cables (7 ) go outside the wind tower (8). The choice of one embodiment or another depends on the diameter of the metallic wind tower. In general, the reinforcement cables (7) are arranged inside the wind tower (8), but in the case of very narrow towers, said cables are arranged outside.

Figure 10 shows a lower anchor (15) that can be arranged at the lower end of the dynamic modulators (6) and configured to join to join the lower base surface (5) or the foundation. It is a delta-shaped reinforced concrete element that is configured to connect the dynamic modulators (6) to the foundation and to pass the reinforcement cable (7) that runs through the dynamic modulator (6) to the foundation. Said lower anchor (15) also comprises registration for the testing mechanism.

Although no representative figure of a preferred embodiment of the invention is provided, the invention also encompasses a rigid pedestal that does not physically incorporate the shaft (2), since the dynamic modulators (6) of post-tensioned reinforced concrete are joined together by making the function of the shaft (2) and these modulators are attached to the upper base (4) where the wind tower is fixed.

Claims

1. - Rigid wind tower pedestal configured to be installed between a foundation and a wind tower already designed without modifying its design, and is characterized by comprising at least:

- an optional structural shaft (2) comprising a plurality of horizontal structural elements (3) of prestressed reinforced concrete, joined together forming horizontal divisions and comprising an upper base surface (4) to which the wind tower is attached and a lower base surface (5) that is attached to the foundation;

-a dynamic modulators (6), of prestressed or post-tensioned reinforced concrete, which are connected at one end to the upper base surface (4) or to a horizontal structural element (3) of the shaft and at the other end are connected to the base surface bottom (5) or to the foundation, and said dynamic modulators (6) adjust the dynamic characteristics, such as the frequency of the system so that loads do not vary.

2. - Rigid wind tower pedestal according to claim 1 characterized in that the dynamic modulators (6) joined together to the upper base (4) where the wind tower is attached, act as a shaft (2) of the pedestal (1)

3. - Rigid wind tower pedestal according to claim 1 characterized in that it comprises at least one horizontal bypass structural element (14) disposed in the shaft (2) attached to at least one of the horizontal structural elements (3) thereof and It is configured to join one end of the dynamic modulators (6).

4. - Rigid wind tower pedestal according to claim 3 characterized in that in the horizontal diverting structural element (14) a reinforcement cable (7) is anchored extending from the upper base surface (4) in the vertical direction and a reinforcing cable (7) that extends along the dynamic modulator.

5. - Rigid wind tower pedestal according to claim 3 characterized in that the horizontal diverting structural element (14) is crossed by a reinforcement cable (7) that changes trajectory inside the horizontal diverting structure passing from a vertical path to an inclined path.

6. - Rigid wind tower pedestal according to claim 1 characterized in that the horizontal structural elements have a configuration that can be cylindrical or polygonal.

7. - Rigid wind tower pedestal according to claim 1 characterized in that the horizontal divisions are dry joints and the horizontal structural elements are held together by the reinforcement cables.

8. - Rigid wind tower pedestal according to claim 1 characterized in that the horizontal structural elements (3) have an upper face (10) and a lower face (11) and comprise at least one recess (12) in the upper face ( 10) and a protrusion (13) on the underside (11).

9. - Rigid wind tower pedestal according to claim 8 characterized in that the at least one recess (12) and the at least one shoulder (13) are complementary so that when joining two equal horizontal structural elements the at least one shoulder (13 ) of the lower face (11) of one of the horizontal structural elements (3) is housed in the at least one recess (12) of the upper face (10) of the other horizontal structural element (3).

10. - Rigid wind tower pedestal according to claim 8 characterized in that the recesses (12) and projections (13) extend along the entire section of the upper face (10) and the lower face (11) respectively.

11. - Rigid wind tower pedestal according to claims 1 and 2 characterized in that it additionally comprises a lower anchor (15) attached to one end of the dynamic modulators (6) and configured to join the lower base surface (5) or the foundation, and inside the end of the reinforcement cable (7) that extends along the dynamic modulator (6).