NO20230014A1

NO20230014A1 - A wind power plant

Info

Publication number: NO20230014A1
Application number: NO20230014A
Authority: NO
Inventors: Geir Lasse Kjersem
Original assignee: Tebina Energi As
Priority date: 2023-01-06
Filing date: 2023-01-06
Publication date: 2024-07-08
Also published as: WO2024147740A1; NO348101B1

Description

Title: A wind power plant

Field of the invention

The present invention relates to a wind power plant and a method for assembly of a wind power plant. The wind power plant comprises a rotor-nacelle assembly with blades, a tower, a substructure and a foundation.

Background of the invention

The increasing size of wind power plants and the need to reduce both investment and operational costs, as well as exploiting wind resources more efficiently, both on land and at offshore sites, are introducing new challenges for the wind industry.

Various configurations of wind power plants are known. Most modern wind power plants comprise a tubular tower structure, where the tubular structure may be made from steel and/or concrete, and may be made from a single segment or may comprise a larger or smaller number of various segments.

So-called monopile support structures introduce problems in terms of manufacturing, installation and sensitiveness towards soil structure interaction. The increasing heights of such structures increases investment cost and complicates access to nacelles, where mobilization of expensive mobile cranes, either floating units at sea or wheeled vehicles on land, will be required for maintenance and inspection.

An alternative solution is represented by so-called hybrid jacket tower concepts, comprising of a space-frame substructure supporting a tubular tower. A further alternative solution is a lattice support structure. These have some attractive features, but with the heavy and complex nacelle located high above ground or sea level, the access to the nacelle for maintenance will be as complex as for the monotower solutions.

Taller towers may exploit or utilize stronger wind resources that exist at higher heights, beyond the reach of today’s typical turbines. Higher hubs on wind turbines may also reduce interference from trees, buildings, and other topographical features and provide additional clearance needed for longer blades, all of which increases energy capture per turbine.

Size increases have led to greater output from turbines under ideal conditions, also known as the nameplate capacity, which has gone from 100 kW per turbine in the 1980s to approximately 2.2 MW per turbine in 2017. In that same time frame, the average U.S commercial wind turbines hub height increased from 20 m to 84 m and rotor diameter has expanded from 20 m to 108 m.

Key technology attributes enabling cost reductions realized to date include advancements that have resulted in the capture of turbine, balance of station (BOS), and operation and maintenance (O&M) economies of scale as well as increased energy production per turbine and per unit of installed capacity. More specifically, increased energy production has been realized with taller towers that place turbines into higher-quality resource regimes as well as larger rotors that enable more of the wind passing by the turbine to be converted into electricity.

However, the taller the wind power plant get, the harder the wind power plant will be to repair and/or maintain. Wind power plants occasionally need big parts, for instance, blades or generators, to be maintained and/or replaced. That is challenging on land, but on land a crane may be supported by the ground.

Floating wind power plants will however operate in water often too deep for jackup vessels to work, so the service vessel must remain floating and thus having two moving structures to shift load from and to. This is technically demanding and thus hard to do in a cost-effective way.

Hence, a challenge today by going taller is increased investments and cost, and possible loss of income due to difficult maintenance and downtime of the wind power plant.

A challenge is also the amount of weight of the steel used in a large mono tower wind power plant. For instance, a tall monopile construction will require a big and heavy foundation pile to penetrate the ground on land or the seabed at sea. The diameter of such holes for the foundation pile may be 6-8 meter in diameter and will require expensive soil preparations prior to installing the large monotower foundation pile and securing it to the soil, which is far more expensive than preparing the foundation based on a number of small diameter piles with conventional sizes and moderate weights enabling the use of traditional construction and support equipment A monopile construction at sea is also subject to higher hydrodynamic forces compared to a lattice type jacket structure, given the same topsides loads.

A lattice type jacket structure at sea is attractive to minimize environmental forces from waves, sea currents and wind. However, when a monopile structure is installed onto the top of such a lattice type jacket structure, as is the common technology today, a larger transition piece is required on top of the jacket structure, giving, together with a heavier substructure, a rather large total mass. In addition, when a monopile is installed onto the top of a preinstalled lattice type jacket structure at sea, an expensive heavy lift barge will be required to lift and support the installation of both the monotower structure and subsequently, the nacelle.

Jacket substructures/foundations are classically three-or four-legged triangulated structures all made of circular steel tubes. On top of the jacket structure is installed a transition piece, typically a plated structure, which is designed with a large center steel tube for connection with the tower. The jacket is typically anchored into the seabed by piles installed at each jacket leg.

Lattice towers are typically manufactured by means of welded or bolted tubular steel profiles or L-section steel profiles. The lattice towers are typically three-four-legged and consist of corner chords interconnected with bracings in a triangulated structure.

DE 10111 280 A relates to a wind power plant, where the wind power plant has a mast made up of segments each placed one above the other at least in part so that each new segment to be installed can be inserted beneath an existing segment which has previously been raised up by a lift mechanism. The mast sections are tensioned against the ground by cables or other traction means. The tensioning force can be adjusted by an electronic control device taking into account the increase in the height of the mast.

WO 2011/055021 A2 relates to a method and an apparatus for assembling a wind power plant, where the wind power plant is assembled from elements by placing these elements on top of each other and by connecting the elements placed on top of each other together. At the mounting site of the wind power plant, an installation construction is formed, which surrounds the wind power plant to be assembled at at least two points spaced from each other and whose height is at least the height of one single element of the mast of the wind power plant but is lower than the complete wind power plant, with at least one open location, through which at least the elements of the mast of the wind power plant can be transferred at least partly to the inside of the installation construction. Elements of the wind power plant in the installation construction are lifted with a lifting device upwards by at least the height of the next element of the mast to be brought into the installation construction; and the next lower element of the mast is always transferred and placed under each preceding element of the mast transferred into the installation construction. In the method according to the invention, at least one unit of the wind power plant that comes in the upper part or on the upper end of the uppermost element of the mast of the wind power plant is mounted on the uppermost element of the mast before the elements of the mast lower than the uppermost element of the mast are installed below the uppermost element of the mast.

US 2009/025304 A1 relates to a tower construction with an annular cross section, comprising one or more component tubes arranged concentrically one on top of the other, wherein at least one component tube is composed of at least three tube segments, the tube segments of at least one component tube are pretensioned relative to one another by means of tensioning devices, hereinafter referred to as segment tensioning devices, and the component tubes have tensioning devices, hereinafter referred to as component tube tensioning devices, which act at least in the axial direction and extend over at least one horizontal joint, the tube segments and the component tubes composed therefrom form, at their butting edges, joints having gaps, the gaps of the joints are filled at least partially with a joint-filling material, and the joints between the tube segments of the same component tube allow a certain, substantially constraint-free rotation of the adjoining tube segments about the joint axis.

US 2011/0239584 A1 relates to a method of building a hybrid tower, a metal mast is erected and connected to a foundation and a concrete structure having a plurality of superimposed concrete segments is built around the metal mast by using the metal mast as a support. Afterwards, the metal mast is disconnected from the foundation and lifted by telescoping and guiding the metal mast along concrete structure.

Finally, the lifted metal mast is connected to the concrete structure. Building of the concrete structure comprises: (a) installing at least one first segment of the concrete structure; (b) lifting the installed segment(s) of the concrete structure along the metal mast by guiding the lifted segments of the concrete structure using the metal mast, so as to clear a space having a sufficient height to receive a next segment of the concrete structure; (c) installing the next segment of the concrete structure in said space; and (d) repeating steps (b) and (c) until a last segment of the concrete structure is installed at a bottom part of the concrete structure.

Objects of the present invention

It is an object according to the present invention to minimize and possibly alleviate one or more of the disadvantages of the prior art, or to provide a useful alternative.

Yet an object according to the present invention is to be able to build higher wind power plants to reach higher altitudes where the wind resources are more stable and will give a higher capacity factor for the wind power plant, and hence better economics, without compromising the access to the nacelle for maintenance and repair.

It is also an object according to the present invention to utilize as best as possible the capacity of the steel used, particularly in a substructure of the wind power plant, both during assembly and during operation.

A further object according to the present invention is rendering use of mobile cranes superfluous for both construction and maintenance support, both on land and at sea.

It is also an object according to the present invention to provide onshore and offshore wind power plants, which are environmentally friendly.

Yet an object according to the present invention is to provide a modularized mast with the possibility of affordable, standardized modules.

An even further object according to the present invention is to provide a reinforcement arrangement for the wind power plant.

In medium sea water depth, regarding marine environment impact, the present invention may possibly present the following advantages. The substructure of the wind power plant according to the invention may be designed as a lattice structure and installed onto the seabed in moderate water depths, for instance down to 100 – 150 meters water depth, like traditional offshore steel jackets, and piled to a seabed. From an environmental perspective will lead to a small or moderate occupation of seabed area. Sea water will be free flowing, and the sea volume entrapped by the substructure could function as protected habitat for marine life.

In ultra-deep-water installation, regarding marine environment impact, the present invention may possibly present the following advantages. The substructure of the wind power plant may also be installed onto a floater designed for deep water installation, for instance in water depths down to 2,000 meters, using technologies well known from the offshore industries. Such a floater may, for instance, be of a semisubmersible design, as illustrated in figure 7 of the present application, or a SPAR buoy type floater, being catenary moored to the seabed. Alternatively, the floater may be designed as a tension leg platform (TLP) or a SPAR buoy with TLP mooring. From a marine environmental perspective, the TLP mooring has an advantage by occupying small areas of the seabed compared to the vast seabed areas occupied by catenary moorings.

Regarding foundation effects from substructure installed in shallow marine environment, the present invention may possibly present the following advantages. The substructure of the wind power plant according to the invention can be founded to the ground, or to a seabed, by using a number of moderately sized piles, driven into the ground taking advantage of well-known piling techniques. This allows the substructure of the invention to be installed or erected in most types of soils and terrain topographies. Compared to local blasting this foundation method has minimum local environmental impact compared to e.g. need for blasting or drilling huge holes to accommodate large monotower structures. These environmental aspects are especially important in shallow and sensitive sea water locations being breeding grounds for marine life.

The present invention may have a positive impact on local shallow water environment. The substructure of the wind power plant according to the present invention may be installed or erected in ultra-shallow waters, both in benign and harsh environments where water at times will be breaking the reefs, i.e. areas were water depths may vary from – 20 meters to 5 meters relative to sea level. These marine environments are often habitats fish and are also their breeding grounds. These splash zone areas are often located far from populated areas and therefore attractive to energy installations such as wind farms which does not inflict lasting damage to the marine life, as will the case with the present invention. A lattice structure of the substructure may become protective habitats for marine life and be fitted with small artificial reef structures which may improve hiding and breeding areas for local fish underneath the lower deck. The working deck areas of the substructure may also be vacant during remote operations of the wind turbines, allowing accommodation of research activities on the local wild life.

Wind turbines emits noise which affects the local environment. For reducing noise impact on the environment, both on land and at sea, by for instance insulation, the present invention may possibly present the following advantages. Compared to short term ship traffic, long term and almost continuous wind turbine noise, being transmitted to the seabed via the tower and support structures, may over time have negative impact on local marine life. The design of the substructure of the wind power plant according to the invention may be tailored/designed to significantly reduce or eliminate such structurally transmitted to the environment. This is obtained by implementing commercially available, flexible, sound absorbing material to the guide systems, such as stiff rubber, etc. By introducing also sound absorbing material to the bottom mast support and guide system, most of the noise transmitted from the wind turbines via the tower structure towards the seabed (or local land soil) environment, can be removed by the wind power plant according to the present invention.

For reducing noise and environmental impact, by for instance taller towers, the present invention may possibly present the following advantages. A feature of the present invention is that the wind turbines may be economically installed at taller heights than being possible today, e.g. up to 250 – 300 meters. Such an increased height will be positive for the local ground or seabed environment, due to increased distance from noise source. In addition, the local bird life will take advantages of less risk for birds colliding with the rotating turbine blades.

In building the wind power plant and the tower, guy lines pre-tensioning the tower may be used, and which follows the tower during building. Such guy lines may improve buckling length of the tower and could possibly also reduce the total weight of the tower structure.

Summary of the invention

According to an aspect of the invention, a self-elevating wind power plant is provided, where the self-elevating wind power plant comprises a rotor-nacelle assembly with blades, a tower and a foundation. The substructure comprises a first guide collar and a second guide collar for support of the tower, where the first guide collar may be located in a lower part of the substructure and the second guide collar may be located in an upper part of the substructure. Furthermore, the substructure comprises a support structure arranged between the first and second guide collars, a jacking system for lifting and lowering of said tower being suspended from said support structure, a reinforcement structure further being connected to the tower.

According to one aspect, the substructure may comprise at three upright elongated elements connected to each other through said first and second guide collars, where the elongated elements are arranged in a triangular form. The elongated elements may be arranged to extend substantially vertically upwards from the ground or the foundation, or the elongated elements may also be arranged to form an angle with the ground or foundation, for instance to provide a pyramidal form.

The jacking system may be any known hoisting or lifting mechanism capable of elevating the tower and tower segments during assembly of the tower, and to elevate assembled tower segments in a vertical direction at least to a height corresponding to one tower segment, thereby allowing assembly of a subsequent tower segment to a previously assembled and elevated tower segment.

According to one aspect, the jacking system may comprise a plurality of stepwise hydraulic cylinders arranged spaced apart around a periphery of the support structure, where each stepwise hydraulic cylinder, through one of its ends, is connected to the support structure. An opposite end of each stepwise hydraulic cylinder is connected to an end of a wire or chain in appropriate ways, each wire or chain being, through its opposite end, connected to a common yoke adapted for receipt of a tower segment.

According to another aspect, the jacking system may comprise a plurality of winch wheels arranged spaced apart around a periphery of the support structure, where each winch wheel through a wire or chain is connected to a common yoke adapted for receipt of a tower segment.

The jacking system may in one embodiment comprise hydraulic pressure cylinders attachable to the tower segment, said hydraulic pressure cylinders comprise lower and upper claws for gripping and locking onto T shaped vertical guide rails on the tower segment, and wherein the hydraulic pressure cylinders are activatable to force the tower segments upwards during assembly of the tower.

The jack-up assembly may in another embodiment comprise a rack and pinion system, said rack and pinion system being activatable to force the tower segments upwards during assembly of the tower.

The jack-up assembly may in a further embodiment comprise a winch system connected to a support platform, said winch system being activatable to force the platform and the tower segments upwards during assembly of the tower.

The first and/or second guide collar may further comprise elastic dampers in order to absorb vibration from the tower.

The substructure may possibly comprise a third guide collar located between the first guide collar and the second guide collar, wherein the third guide collar has a closable and openable aperture allowing through going axial movement of the tower segments. Similarly, the third guide collar may also comprise elastic damper(s).

Each of the first, second and the third guide collars may be provided with a closable and openable aperture, thereby allowing a through-going axial movement of the tower segments.

According to one aspect, the reinforcement device may comprise a plurality of modules, each module further comprising a number of beams, where the plurality of modules, when interconnected, form a structure in the form of a single or double pyramid. However, it should be understood that the reinforcement device also may have other shapes, for example a rectangular shape, an oval shape, a polygonal shape or the like.

Each end of the beam of the modules of the reinforcement device may be provided with a fastening arrangement in order to be able to connect two beams and/or an adjacent tower segment to each other.

The beams may have the same or different length, same or different thickness etc.

In one embodiment a number of wind turbines with vertical axis may be connected to the tower of the wind power plant.

Each tower segment may be a tubular pipe or a lattice section.

Furthermore, each end of the tower segment may be provided with a flange and/or vertical guide rails.

The tower and/or the tower segments may be provided with one or more attachment lugs for guy lines.

According to one aspect the substructure may be a lattice structure.

In one embodiment the substructure and the foundation may be integrated with each other.

The tower and/or the tower segments may comprise attachment lugs for guy lines.

The jack-up assembly can be located on or adjacent the first guide collar.

The foundation of the wind power plant may comprise a storage- and assembly room for unassembled tower segments.

The jacking system is arranged to elevate assembled tower segments in a vertical direction to a height corresponding to one tower segment, allowing assembly of a new tower segment to a previously assembled and elevated tower segment.

The foundation may comprise a downward directed conical support as a bearing point against a bearing structure.

The foundation may also be supported on an elastic bearing structure.

The foundation may in one embodiment comprises a crane.

When the wind power plant according to the invention is assembled, this can be done by the following steps: assembling the substructure with a first guide collar and a second guide collar for support of the tower, building the tower by assembling a plurality of tower segments using the jacking system, where the jacking system elevates assembled tower segments in a vertical direction through said first and second guide collars.

The method comprises stepwise building of the tower by elevating assembled tower segments in a vertical direction to a height corresponding to one tower segment, allowing assembly of a new tower segment to a previously assembled and elevated tower segment.

The method may further comprise the steps of mounting the rotor-nacelle assembly and blades on top of a first part of the tower extending above the substructure, and to assemble and elevate tower segments carrying the first part of the tower with the rotor-nacelle assembly and blades to a desired height.

The method may comprise the steps of assembling tower segments to construct said first part of the tower.

The method may comprise the step of inserting said first part of the tower in the substructure.

The method may comprise the step of assembling on site the substructure on the foundation using a crane mounted on the foundation.

The method may comprise the step of assembling the substructure as a lattice structure on the foundation.

The method may comprise the steps of transporting the wind power plant to an offshore platform, wherein the rotor-nacelle assembly and blades are preinstalled on top of a first part of the tower extending above the substructure, and to assemble and elevate tower segments carrying the first part of the tower with the rotor-nacelle assembly and blades to a desired height.

The method may comprise the step of connecting guy lines to the tower.

The method may also comprise the steps of connecting guy lines to one or more tower segments after the assembled tower segments are elevated in the vertical direction through and above said second guide collar, and to adjust tensioning of the guy lines during elevating of the tower.

Description of the figures

Embodiments of the present invention will now be described, by way of example only, with reference to the following figures, wherein:

Figure 1 shows a first embodiment of a wind power plant according to the present invention,

Figure 2 shows a second embodiment of a wind power plant according to the present invention,

Figure 3 shows a third embodiment of a wind power plant according to the present invention,

Figure 4 shows a fourth embodiment of a wind power plant according to the present invention,

Figure 5 shows a fifth embodiment of a wind power plant according to the present invention,

Figure 6 shows a sixth embodiment of a wind power plant according to the present invention,

Figure 7 illustrates a very tall wind power plant according to the present invention,

Figures 8 to 14B show further embodiments of the wind power plant according to the present invention, where a reinforcement device is connected to the tower of the wind power plant,

Figure 15 shows the reinforcement device in greater detail,

Figure 16 shows a tower segment which is used to assemble the tower of the wind power plant,

Figures 17 to 20 show additional embodiments of the wind power plant according to the present invention, where one or more wind turbines with vertical axis is/are connected to the assembled tower of the wind power plant,

Figure 21 illustrates sequentially building of a wind power plant according to the present invention,

Figure 22A illustrates building of a wind power plant according to the invention on an offshore platform,

Figure 22B illustrates a wind power plant according to the invention on a floating offshore platform, and

Figures 23 to 24 show an example of a jacking system used in the wind power plant according to the invention.

Description of preferred embodiments of the invention

The present invention relates to a wind power plant, such as a wind power plant 10 comprising a rotor-nacelle assembly (RNA) 12 with a number of blades 14, and a vertical, modular tower 16 supported by a substructure 20 and a foundation 22. The substructure 20 and the foundation 22 may be integrated with each other, and thus be viewed as one structure. The substructure 20 may, as shown in figure 6, be a lattice structure. The foundation 22 may also be a lattice structure, or a more traditional support structure. The wind power plant 10 is a jacked wind power plant, and may also be called a self-elevating wind power plant.

The vertical tower 16 comprises a number of assembled tower segments 18, where a new tower segment 18 is added and connected to the number of already assembled tower segments 18 as the height of the vertical mast 16 is increased.

The substructure 20 comprises a first guide collar 24 and a second guide collar 26 for support of the tower 16, as seen particularly in figures 1-5. The first guide collar 24 is located in a lower part of the substructure 20 and the second guide collar 26 is located in an upper part of the substructure 20, such that the first and second guide collars 24, 26 supports the tower 16 during erection and after the tower 16 is erected. The substructure 20 must therefore be a support structure erected to a sufficient height for the first and second guide collars 24, 26 to be spaced apart a vertical distance enough to provide lateral support to the tower 16.

As shown in figures 1-6, the substructure 20 may be a support structure having many shapes, for instance, a tapering shape (pyramid) over its height, a parallel shape (rectilinear shape), or the like, where the first and second guide collars 24, 26 are arranged to take up lateral forces.

The substructure 20 further comprises a jacking system 30 for receipt of modular tower segments 18, providing what can be called "a stepwise tower building block concept". The tower segments 18 are assembled in the substructure 20 and erectable by the jacking system 30 to provide an assembled tower 16. The jacking system 30 is preferably provided between the first and second guide collar 24, 26.

The first guide collar 24 and the second guide collar 26 comprises each an aperture allowing through going axial movement of the tower 16 or the tower segments 18, where said apertures may be being closable and openable. The first guide collar 24 and the second guide collar 26 may also comprise elastic dampers, such as elastic rubber parts, that can absorb vibration from the tower 16 and thus reduce background noise.

The foundation 22 may also be supported on an elastic bearing structure 64, for instance as seen in figures 26 to 29, to further provide noise reduction.

The substructure 20 of the wind power plant 10 may further comprise a third guide collar 28 located between the first guide collar 24 and the second guide collar 26, wherein the third guide collar 28 similarly has a closable and openable aperture allowing through going axial movement of the tower 16 or the tower segments 18. The third guide collar 28 may optionally comprise an elastic damper, such as elastic rubber parts, for reduction of background noise.

The first guide collar 24, the second guide collar 26 and possibly the third guide collar 28 may be a circular collar having an internal aperture. In one embodiment, the aperture may be closable by using one or more wedges in the aperture between the collar and the tower 16 or the tower segments 18, and openable by removing the wedges. In a second embodiment, the circular collar may be made up of two semicircular parts, each being connected to a pressure cylinder pushing or retracting the semi-circular parts to and from each other. The aperture is thus closable by pushing the semi-circular parts towards each other to clamp the tower 16 or the tower segments 18 in between them, and openable by retracting the semi-circular parts.

The jacking system 30 may be basically any known hoisting or lifting mechanism capable of elevating the tower 16 and the tower segments 18 during assembly, and to elevate assembled tower segments 18 in a vertical direction at least to a height corresponding to one tower segment 18, allowing assembly of a new tower segment 18 to a previously assembled and elevated tower segment 18.

Figure 1 shows a jacking system 30 comprising a winch system 52 connected to a support platform 54. The winch system 52 is activatable to force the platform 54 and the tower segments 18 upwards during assembly of the tower 16. The jacking system 30 comprises gripping members gripping and holding the lower tower segments 18 prior to being elevated and during assembly of a next tower segment 18 to a previously assembled and elevated tower segment 18.

Figure 2 shows another example of a jacking system 30 with gripping elements gripping and holding the lower tower segments 18 prior to being elevated and during assembly of a next tower segment 18 to a previously assembled and elevated tower segment 18.

Figures 3 to 5 show further embodiments of a jacking system 30 used when the vertical, modular tower 16 the wind power plant 10 according to the present invention is assembled.

Figure 3 shows an embodiment of the jacking system 30, where the jacking system 30 is mounted to the substructure 20 of the wind power plant 10. In this embodiment the substructure 20 comprises three elongated elements 103 arranged to form a triangular shape, where the three elongated elements 103 are fixedly connected to the foundation 22 and further connected to each other through the first and second guide collars 24, 26.

Furthermore, the substructure 20 comprises a support structure 100 for the jacking system 30, where the support structure 100 is arranged between the first and second guide collars 24, 26.

In the shown embodiment the support structure 100 for the jacking system 30 is arranged closer to the second guide collar 26, but it should be understood that the support structure 100 for the jacking system 30 also could be arranged closer to the first guide collar 24.

In this embodiment the jacking system 30 comprises a plurality of stepwise hydraulic cylinders 102 arranged spaced apart around a periphery of the support structure 100, where each stepwise hydraulic cylinder 102 is connected to a wire 103 or chain.

Each wire 103 or chain is then, in turn, connected to a common yoke 101, where the yoke is adapted for receipt of a tower segment 18. When the tower segment 18 is arranged within the common yoke 101, the flange 18a provided on an upper end of the tower segment 18 will be used to lift the tower segment 18.

The jacking system 30 is shown in its lowermost position, i.e. a position where a tower segment 18 is connected to the lowermost tower segment 18 of the previously connected tower segments 18 of the tower 16 and where the jacking system 30 is ready to lift up the tower 16 upwardly to a height above the foundation 22 where it is provided enough space between the lowermost connected tower segment 18 and the foundation 22 in order to be able to insert a new tower segment 18 on the floor of the foundation 22.

The above is shown in figure 4, where it can be seen that the jacking system 30 has been lifted to its uppermost position, whereby a new tower segment 18 has been arranged on the floor of the foundation 22. When the new tower segment 18 has been arranged on the floor of the foundation 22, the jacking system 30 will lower the tower 16 downwardly until the tower 16 abut against the upper side of the new tower segment 18, whereby the new tower segment 18 may be connected to the lowermost tower segment 18 of the assembled tower 16 in appropriate ways.

It is also seen that the tower 16 has a downwardly directed conical support 50 as a bearing point against the foundation 22.

Figure 5 shows yet an embodiment of a jacking system 30 according to the present invention, where the jacking system 30 comprises a plurality of winch wheels 104 arranged spaced apart around a periphery of said support structure 100, each winch wheel 104 further being connected to a common yoke 101 adapted for receipt of a tower segment 18. When the tower segment 18 is arranged within the common yoke 101, the flange 18a provided on an upper end of the tower segment 18 will be used to lift the tower segment 18.

The jacking system 30 according to figure 5 will also be able to lift up the tower 16 to a height that will allow a new tower segment 18 to be placed on the floor of the foundation 22. When the new tower segment 18 has been placed on the floor, the jacking system 30 will be used to lower the tower 16 downwardly until the tower 16 abut against the upper side of the new tower segment 18, whereby the new tower segment 18 may be connected to the lowermost tower segment 18 of the assembled tower 16 in appropriate ways. When the new tower segment 18 is connected to the lowermost tower segment 18 of the assembled tower 16, the steps of lifting up the tower 16 and the arrangement of a new tower segment 18 on he floor of the foundation 22 are repeated, until the tower 16 has reached the desired height.

Figures 23 and 24 show the jack-up assembly 30 as hydraulic pressure cylinders 32 attachable to the tower segment 18. The hydraulic pressure cylinders 32 comprise for instance upper and lower 34, 36 for gripping and locking onto T shaped vertical guide rails 38 provided around a circumference of the tower segment 18. The hydraulic pressure cylinders 32 are similarly activatable to force the tower segments 18 upwards during assembly of the tower 16, and to grip and hold the lower tower segments 18 prior to being elevated and during assembly of a next tower segment 18 to a previously assembled and elevated tower segment 18.

Figure 25 shows a further example of the jack-up assembly 30, comprising a rack and pinion system 40, 42. The rack and pinion system 40, 42 is activatable to force the tower segments 18 upwards during assembly of the tower 16, and to grip and hold the lower tower segments 18 prior to being elevated and during assembly of a next tower segment 18 to a previously assembled and elevated tower segment 18.

Figure 6 and 7 further illustrates that each tower segment 18 may be a tubular pipe section or lattice section of circular and cylindrical shape, for instance equipped with T shaped vertical guide rails 38 for connection to the jack-up assembly 30.

Furthermore, a flange 18a is provided on each end of the tower segment 18, the flanges 18a being used to connect two adjacent tower segments 18 to each other, and also to provide a support for the jack-up assembly 30 when the tower 16 is to be lifted.

The tower 16 may however also be built as a lattice structure with three to four vertical corners, for instance with a similar shape as a traditional jack-ups, which often is triangular, or the tower may be built with a similar shape as traditional tower crane, which often is square. Hence, the tower segments 18 may be of a multisided lattice structure, for instance with three or four sides.

The wind power plant 10 according to the invention may be placed onshore, as illustrated in figure 21 or offshore. Figure 22A illustrates building the wind power plant 10 on an offshore platform 72 with legs, and figure 22B illustrates the wind power plant 10 on a floating offshore platform 72'. A semi assembled wind power plant 10 according to the invention may be shipped to the offshore platform 72, 72' by a barge 74, or the wind power plant 10 may be fully assembled on the offshore platform 72, 72'.

Figure 7 illustrates a very tall wind power plant 10 according to the invention, for instance taller than 250 m. Such a height will improve noise influence and may also reduce bird collisions. To stabilize the tower 16, the tower 16 and/or the tower segments 18 may comprise attachment lugs 62 for guy lines 60 running down to the foundation 22 or to anchor points on the ground or on the seabed.

In this embodiment six guy lines 60 are used to stabilize and/or moor the tower 16 of the wind power plant 10 to the foundation 22 or to anchor points (not shown) on the ground, but it should be understood that a larger or smaller number of guy lines 60 may be used to achieve this purpose.

Furthermore, the tower 16 comprises a large number of assembled tower segments 18.

The wind power plant 10 may comprise a crane 70, for instance arranged on the foundation 22 as seen in figures 21 and 22B, thus rendering use of mobile cranes superfluous. The crane 70 may assist in building the substructure 20 of the wind power plant 10, as seen from top left in figure 21, and possibly also to mounting the rotor-nacelle assembly 12 with blades 14 on the tower 16 prior to starting to assemble the tower segments 18. The crane 70 may receive parts from a barge 74 or the like in case of building offshore or from a truck 76 in case of building onshore.

Figures 26 to 29 illustrates assembly and jack-up of modular tower segments 18 in the wind power plant 10 according to the invention.

As seen in figure 26, the lower part of the substructure 20 or the foundation 22 may comprise a storage and assembly room 44 for storage of tower segments 18 and for assembly of tower segments 18.

Furthermore, the foundation 22 comprises a downwardly directed conical support 50 as a bearing point against a bearing structure 64.

After assembling the substructure 20 with the first guide collar 24 and the second guide collar 26, the tower 16 is built by assembling the modular tower segments 18 using the jack-up assembly 30, wherein said jack-up assembly 30 elevates assembled tower segments 18 in a vertical direction through said first and second guide collars 24, 26.

The tower 16 may in one embodiment be built entirely of modular tower segments 18. When the first tower segments 18 are erected and guided through the second guide collar 26, the rotor-nacelle assembly 12 and blades 14 are mounted on top of the uppermost tower segment 18, and assembling and elevating of subsequent tower segments 18 commences to build the complete tower 16 of the wind power plant 10.

In another embodiment, a first part of the tower 16, being a conventional tower part, carrying the rotor-nacelle assembly 12 and blades 14 may be mounted on top of the uppermost tower segment 18 that has been erected above the second guide collar 26.

In a further embodiment, the first part of the tower 16, being a conventional tower part, carrying the rotor-nacelle assembly 12 and blades 14, is inserted in the substructure 20, for instance as seen in figure 6, and landed on a tower segment 18 erected above the first guide collar 24 in the lower part of the substructure 20.

Assembling and elevating of subsequent tower segments 18 commences thereafter to build the complete tower 16 of the wind power plant 10.

When the wind power plant 10 is to be placed offshore, the wind power plant 10 may be transported to an offshore platform 72, 72' with the rotor-nacelle assembly 12 and blades 14 preinstalled on top of the first part of the tower 16 extending above the substructure 20, and thereafter to assemble and elevate tower segments 18 carrying the first part of the tower 16 with the rotor-nacelle assembly 12 and blades 14 to a desired height.

Figures 27 to 29 illustrate stepwise building of the tower 16. In figure 27 the jack-up assembly 30 starts lifting previous build tower segments 18. In figure 28, the previous assembled tower segments 18 have been elevated in the vertical direction to at least a height corresponding to one tower segment 18, thus allowing assembly of a new tower segment 18 to a previously assembled and elevated tower segment 18, as seen in figure 29. The jack-up assembly 30 will thereafter repeat the process until desired tower 16 is reached.

Guy lines 60, as seen particularly in figure 7, may improve buckling length of the tower 16 and could possibly also reduce the total weight of the tower structure. The guy lines 60 are during assembly connected to one or more tower segments 18 after the assembled tower segments 18 have been elevated in the vertical direction through and above said second guide collar 26. During elevating of the tower 16 and tower segments 18, the tensioning of the guy lines 60 are adjusted. To tension the guy lines 60, one or more constant tension winch(es) (not shown) placed on the ground or placed on the foundation may be used. After final height of the tower 16 has been reached, the guy lines 60 are final tensioned and permanently anchored on the ground. The one or more winches may then be removed and be used on the next wind power plant.

Offshore it is possible to use lump weights connected to the end of the guy lines 60, and which are lifted up from the ocean floor during elevating of the tower 16 and tower segments 18.

The guy lines 60 may, for instance, be wires, tubulars, synthetic fiber cables or similar that can be tensioned.

The present invention also relates to a reinforcement device 200 for the tower 16 of the wind power plant 10, where one or more of such reinforcement devices 200 may be connected to the tower 16 in order to reinforce and/or stabilize the tower 16 of the wind power plant 10, especially when the tower 16 is very high, and/or when the substructure 20 for some reason must is to be removed away from the tower 16.

Figures 8 to 14B show different embodiments of the wind power plant 10 according to the present invention, where such a reinforcement device 200 is connected to the tower 16 of the wind power plant 10, and where the reinforcement device 200 is assembled in accordance with the height of the tower 16 being increased, i.e. in connection with that a new tower segment 18 is connected to a previously assembled and elevated tower segment 18.

The reinforcement device 200 may, in one embodiment, comprise a plurality of beams 201A, 201B, where each beam 201A, 201B, at each of its end, is provided with fastening means 201C in order to be able to connect one beam 201A, 201B to other beams 201A, 201B and/or the tower segments 18.

Figure 8 shows how a first module of the reinforcement device 200 is assembled/built on top of the support structure 100 of the substructure, and connected to the tower 16 of the wind power plant 10.

The first module of the reinforcement device 200 comprises four beams 201A, 201B (i.e. two beams 201A and two beams 201B), where two beams 201A, through their first ends, are connected to flanges 18a of two adjacent and assembled tower segments 18 extending up from the substructure 20 of the wind power plant 10, and where the two beams 201A, from their first ends, are arranged to form an angle with the tower 16. Each of the two beams 201A are furthermore, through their opposite ends (i.e. second ends) connected to an end of a shorter beam 201B, where this shorter beam 201B, is arranged to extend substantially horizontally out from the tower 16. Each shorter beam 201B is furthermore, through its opposite end, connected to the flanges 18a of the two adjacent and assembled tower segments 18 extending a certain distance above the support structure 100 or the substructure 20 of the wind power plant 10 (see for instance figure 1 for this embodiment).

When the four beams 201A, 201B of the first module of the reinforcement device 200 are connected to each other and the tower segment 18, a new tower segment 18 is arranged in the space between the foundation 22 and the lowermost tower segment 18 of the assembled tower 16, whereafter the jacking system 30 is used to lift up the tower 16 to a height where another tower segment 18 may be placed beneath the lowermost tower segment 18, as explained in accordance with figures 28 and 29.

Figure 9 shows how a second module of the reinforcement device 200 is built/assembled to the first module of the reinforcement device 200, where the second module of the reinforcement device 200 also comprises four beams 201A, 201B. Two beams 201A will then, through their first ends and the fastening means 201C, be connected to the beams 201A, 201B of the preceding first module of the reinforcement device 200, i.e. the beams 201A forming an angle with the tower 16 and the substantially horizontal beams 201B.

When the second module of the reinforcement device 200 is built/assembled, the steps of lifting up the tower 16 with the jacking system 30 is repeated once again.

Figure 10 shows how a fourth module of the reinforcement device 200 is built/assembled, while figure 11 shows the completed reinforcement device 200.

During the building/assembling of the reinforcement device 200, the support structure 100 is held taut with the guy lines 60, as seen in figures 8 to 10.

In the embodiment shown in figures 8 to 11, the reinforcement device 200 will have a pyramidal form. However, it should be understood that reinforcement device 200 also could have other shapes or forms, for instance, a square, polygonal form or similar shapes or forms.

Furthermore, it should be understood that plates, girders, braces and the like, or even a combination of such may be used to provide the reinforcement device 200.

Figures 12 to 14B show another embodiment of a reinforcement device 200, where the reinforcement device 200 in this embodiment have a double pyramidal form or shape. It can also be seen that guy lines 60 are connected to the reinforcement device 200, where the guy lines 60 are tightened when the tower 16 reaches its final height, as shown in figure 13.

Figure 14A also shows that the reinforcement device 200 has such a form that it will not prevent the blades 14 of the rotor-nacelle assembly 12 to rotate, even if the reinforcement device 200 is arranged so high up towards the rotor-nacelle assembly 12 that it will lie within the rotation diameter of the blades 14.

Figure 14B shows an embodiment where two reinforcement devices 200 are connected to the tower 16, where the reinforcement devices 200 are arranged spaced apart a distance. Furthermore, in this embodiment, after the tower 16 has been assembled to its desired height, the substructure 20 is removed and the tower 16 is moored or anchored by a plurality of guy lines 60 which are in appropriate ways connected to the reinforcement devices 200.

Figure 15 shows how the beams 201 of a module of the reinforcement device 200 are connected to each other and the tower segment 18. Each beam 201A,201B is, at each of its ends, provided with fastening means 201C, such that each beam 201A, 201B may be connected to, for instance, four adjacent beams 201A, 201B, or to two beams 201A and to flanges 18A of two assembled tower segments 18. One beam 201A (i.e. a beam forming an angle with the tower 16) can therefore be connected or joined to another beam 201A and a beam 201B (i.e. a beam being arranged substantially horizontally) through each of its ends. In a similar way, each beam 201B can be connected or joined to two beams 201A (i.e. the beams forming an angle with the tower 16) and to two assembled tower segments 18A through the flanges 18A of the tower segments 18.

The fastening means 201C provided on each end of the beams 201A, 201B may be one or more flange elements provided with a number of holes (not shown), whereby two adjacent beams 201A, 201B may be connected to each other through the flange elements and bolt and nuts. However, it could be envisaged that the fastening means 201C also can be designed in other way as long as they allow a fastening of the beams 201A, 201B and the tower segments 18 as described above.

Figure 16 shows a tower segment 18 of the tower 16, where it can be seen that the tower segment 18 at each end is provided with a flange 18a, where the flange 18a is used to connect two adjacent tower segments 18 to each other. The flange 18a is also used as a support when the jacking system 30 is used to lift up the tower segment 18 and/or to lift up the tower 16 of the wind power plant 10.

Each flange 18a may be provided with a plurality of holes 30 around its periphery, whereby bolts and nuts may be used when assembling two adjacent tower segments 18.

The flange 18a will also act like a reinforcement for the tower segment 18 and the assembled tower 16

Furthermore, each tower segment 18 is provided with a plurality of vertical reinforcement elements 38 arranged around a circumference of the tower segment 18, where the reinforcement elements 38 may be arranged on an outside, an inside or both an outside and an inside of the tower segment 18.

The tower segment 18 is shown having a same diameter over it length. However, it should be understood that the tower segment 18 also could have a varying diameter over it height.

Figures 17 to 20 show additional embodiments of the wind power plant 10 according to the present invention, where it can be seen that one or more wind turbines 300 with vertical axis may be connected to the tower 16, where the one or more wind turbines 300 may be connected to a top of the tower 16, between the rotor-nacelle assembly 12 and the reinforcement device 200, or below the reinforcement device 200.

Through the wind power plant 10 according to the present invention, a slender tower 16 with low steel weight may be achieved, which is therefore less expensive to manufacture.

The tower 16 will be virtually momentum free at the ground or foundation, which will also result in a reduced steel weight for the entire tower 16.

There will also be substantially pure vertical forces against the ground or foundation, which thus entails a simpler foundation for the tower 16.

Jacking system and substructure may be modular and removed and refitted with inexpensive, commercial crane systems.

The invention is now explained with several non-limiting embodiments. A person skilled in the art will understand that a number of variations and modifications may be made to the wind power plant as described within the scope of the invention as defined in the appended claims.

Claims

1. A wind power plant (10), comprising:

- a rotor-nacelle assembly (12) with blades (14),

- a tower (16),

- a substructure (20), and

- a foundation (22),

wherein the substructure (20) comprises a first guide collar (24) and a second guide collar (26) for support of the tower (16), said first guide collar (24) being located in a lower part of the substructure (20) and said second guide collar (26) being located in an upper part of the substructure (20), the substructure (20) further comprising a support structure (100) arranged between said first and second guide collar (24, 26), and a reinforcement structure (200) connected to the tower (16).

2. The wind power plant (10) according to claim 1, wherein said substructure (20) comprises at least three elongated elements (103) connected to each other through said first and second guide collar (24, 26).

3. The wind power plant (10) according to claim 1, wherein said jacking system (30) comprises a plurality of stepwise hydraulic cylinders (102) arranged spaced around a periphery of said support structure (100), each hydraulic cylinder (102) being connected to a wire (103) or chain, each wire (103) or chain further being connected to a common yoke (101) adapted for receipt of a tower segment (18).

4. The wind power plant (10) according to claim 1, wherein said jacking system (30) comprises a plurality of winch wheels (104) arranged spaced apart around a periphery of said support structure (100), each winch wheel (104) further being connected to a common yoke (101) adapted for receipt of a tower segment (18).

5. The wind power plant (10) according to claim 1, wherein the substructure (20) comprises a third guide collar (28) located between the first guide collar (24) and the second guide collar (26), wherein the third guide collar (28) has a closable and openable aperture allowing through going axial movement of the tower segments

6. The wind power plant (10) according to claim 1, wherein the reinforcement device (200) comprises a plurality of beams (201A, 201B) interconnected to form a structure in form of a single or double pyramidal shape.

7. The wind power plant (10) according to claim 6, wherein each end of the beam (201A, 201B) is provided with fastening means (201C) in order to be able to connect beams (201A, 201B) and/or the tower segment (18) to each other.

8. The wind power plant (10) according to any of claims 6 and 7, wherein the beams (201A, 201B) have same or different length, same or different thickness etc.

9. The wind power plant (10) according to claim 1, wherein a number of wind turbines (300) with vertical axis is/are connected to the mast (16).

9. The wind power plant (10) according to claim 1, wherein each tower segment (18) is a tubular pipe section or a lattice section.

10. The wind power plant (10) according to claim 1, wherein each end of said tower segment (18) is provided with a flange (18a).

11. The wind power plant (10) according to any of the preceding claims, wherein each tower segment (18) is a tubular section equipped with vertical guide rails (38).

12. The wind power plant (10) according to claim 1, wherein the tower (16) and/or the tower segments (18) comprises attachment lugs (62) for guy lines (60).

13. The wind power plant (10) according to claim 1, wherein the foundation (22) comprises a storage- and assembly room (44) for unassembled tower segments (18).

14. The wind power plant (10) according to claim 1, wherein the foundation (22) comprises a downward directed conical support (50) as a bearing point against a bearing structure (64).

15. The wind power plant (10) according to claim 1, wherein the foundation (22) is supported on an elastic bearing structure (64).

16. The wind power plant (10) according to claim 1, wherein the foundation (22) comprises a crane (70).

17. The wind power plant (10) according to claim 1, wherein the first and/or second guide collars (24, 26) comprises elastic dampers.