阅读说明：本技术 空中风能系统 (Aerial wind energy system ) 是由 T·L·鲍恩 P·林德霍斯特 于 2018-05-04 设计创作，主要内容包括：本发明涉及一种用于拆卸风力涡轮机并架设风能产生系统的方法,其中,所述风力涡轮机包括放置在风力涡轮机场地的基座上的塔架以及具有安装在所述塔架上的转子的机舱。该方法包括以下步骤：从所述风力涡轮机去除所述转子,经由线缆将用于产生电力的空中风能系统安装在其余风力涡轮机的部分上以及经由输电线将所述空中风能系统电连接到电网。(The present invention relates to a method for disassembling a wind turbine and erecting a wind energy generating system, wherein the wind turbine comprises a tower placed on a foundation of a wind turbine site and a nacelle having a rotor mounted on the tower. The method comprises the following steps: the rotor is removed from the wind turbine, an aerial wind energy system for generating electrical power is mounted on a part of the remaining wind turbine via cables and the aerial wind energy system is electrically connected to the grid via power lines.)

1. A method for disassembling a wind turbine and erecting a wind energy generating system, said wind turbine comprising a tower placed on a foundation of a wind turbine site and a nacelle having a rotor mounted on said tower, the method comprising the steps of:

removing at least the rotor from the wind turbine;

installing an aerial wind energy system for generating electrical power on the remainder of the wind turbine via a cable; and

electrically connecting the airborne wind energy system to a power grid via a power transmission line.

2. The method of claim 1, wherein the step of installing the airborne wind energy system is performed by mechanically connecting the cable to a main shaft of the wind turbine.

3. The method of claim 1, further comprising removing at least the nacelle from the wind turbine and installing the airborne wind energy system on at least a portion of the wind turbine tower.

4. The method of claim 3, wherein the step of installing the airborne wind energy system is performed by installing a platform carrying the airborne wind energy system on a wind turbine yaw bearing.

5. The method of claim 3, further comprising the step of removing at least one tower section of the wind turbine tower, and wherein the step of installing the airborne wind energy system is performed by installing a platform carrying the airborne wind energy system on a tower flange.

6. The method of claim 1, further comprising removing at least the nacelle and the tower from the wind turbine and installing the airborne wind energy system on the base of the wind turbine tower.

7. The method according to any of the preceding claims, further comprising the step of electrically connecting the airborne wind energy system to a power line previously used for electrically connecting the wind turbine to the power grid.

8. The method of claim 7, wherein the step of connecting the airborne wind energy system to the power transmission line comprises electrically connecting the airborne wind energy system to a transformer of the wind turbine.

9. A method according to any of the preceding claims, wherein the airborne wind energy system is mounted to the part of the wind turbine via a mounting base, the mounting base being rotatably connected to the wind turbine tower.

10. The method according to any of the preceding claims, further comprising the step of positioning at least a part of the airborne wind energy system within the wind turbine tower and/or within the nacelle of the wind turbine.

11. The method of claim 10, wherein the portion of the airborne wind energy system is positioned within the wind turbine tower and/or within the nacelle of the wind turbine when not in operation.

12. A wind energy generating system comprising at least a portion of a wind turbine on a foundation on a wind turbine site and an airborne wind energy system for generating electrical energy for an electrical grid, the airborne wind energy system being coupled to the portion of the wind turbine via a cable and a wind turbine yaw bearing operated by a motor, the airborne wind energy system further being electrically connected to the electrical grid via a power transmission line.

13. The wind energy generating system of claim 12, further comprising a control system for controlling the electric motor.

14. The wind energy generating system of any one of claims 12 to 13, wherein the airborne wind energy system is electrically connected to a power line previously used for electrically connecting the wind turbine to the power grid.

15. The wind energy generating system of any one of claims 12 to 14, wherein the airborne wind energy system is electrically connected to the transmission line via a wind turbine transformer.

16. The wind energy generating system of any one of claims 12 to 15, wherein the airborne wind energy system comprises at least one airborne generator.

17. The wind energy generating system of any of claims 12 to 15, wherein the airborne wind energy system comprises at least one generator positioned at or near the wind turbine tower.

18. The wind energy generating system of any one of claims 12 to 17, further comprising a control structure configured to control movement of the portion of the airborne wind energy system that is launched to a higher elevation.

19. The wind energy generating system of claim 18, wherein the control structure is configured to execute a predetermined movement pattern that effects rotational movement of the airborne wind energy system.

20. The wind energy generating system of claim 19, wherein the rotational movement is substantially circular.

Technical Field

The present invention relates to a method for disassembling a wind turbine and erecting a wind energy generating system comprising an airborne wind energy system. The invention also relates to an aerial wind energy system.

Background

Modern wind turbines are used to generate electrical energy for the grid. To this end, a set of wind turbine blades coupled to the rotor is aligned with the oncoming wind, and the wind turbine blades extract wind energy, which causes the rotor to rotate, thereby converting the energy of the wind into mechanical energy. The rotor is connected to a generator, either directly or via a gear arrangement, so that the mechanical energy at the rotating rotor is converted into electrical energy. The electrical energy is supplied to the grid via suitable components.

Over the years, the size and dimensions of wind turbines have generally increased in order to increase the amount of energy extracted from the wind and increase annual energy production. With significantly longer blades and larger generators, there is a corresponding higher wind turbine tower, larger and significantly heavier nacelle and larger bearings, etc. Thus, it is naturally necessary to dimension the tower and foundation to withstand the greater loads and vibrations caused by the wind acting on the larger and heavier systems.

Thus, in general, it is not possible to simply upgrade or upgrade an existing wind turbine to a version with a higher power output without replacing the foundation and tower and possibly the power line, which is essentially equivalent to erecting a completely new wind turbine. Thus, existing wind turbines are typically maintained as profitable as long as possible by servicing to the extent possible, and then eventually taken out of service. Typically, non-productive wind turbines are left on site because of the cost of disassembling and disposing of the wind turbines.

Other wind energy generating systems are known, such as various airborne wind energy systems, in addition to wind turbines, which are capable of capturing wind energy at a higher altitude than conventional wind turbines. Common to these systems is that parts of the system are launched to a high altitude, collecting wind energy at high altitudes. The collected energy is transferred to the ground station in the form of mechanical energy or in the form of electrical energy. Where the energy transferred is in the form of mechanical energy, a generator will typically be arranged at the ground station to convert the mechanical energy to electrical energy. In case the transferred energy takes the form of electrical energy, the airborne wind energy system comprises an airborne generator, i.e. the part of the system that is transmitted to a higher level comprises a generator. The part of the airborne wind energy system that is launched to a higher height may for example comprise a kite or glider.

The aerial wind energy system is typically launched from an attachment location on the ground, which requires a separate foundation and cable of sufficient length to allow the aerial wind energy system to be launched to the desired higher height.

A number of Airborne Wind Energy Systems are described by Cherubini et al in "air Wind Energy Systems: A review of the technologies" (Renewable and susteable Energy Reviews,51(2015) 1461-.

US 2007/0126241 discloses a wind driven device for an aircraft power generation system comprising a driven element and a controller. The driven element is configured and shaped to provide maximum force from lifting and towing during the downwind phase of operation and minimum force during the upwind phase. The driven element has a sail portion (fail portion) with a leading edge and a trailing edge. The controller changes the driven element between a high-force configuration for downwind operation and a low-force configuration for upwind operation, adjusts the pitch and azimuth angles of the driven element, and controls camber (camber). In one embodiment, the driven element is attached to a shaft that is rotatably mounted on the nacelle on top of the tower.

Disclosure of Invention

It is an object of embodiments of the present invention to provide a method of erecting a wind energy generating system that reuses components from previous wind turbines and/or wind turbine sites.

It is a further object of embodiments of the invention to provide a fast and simple method of establishing an airborne wind energy system coupled to an electrical grid at relatively low cost.

It is a further object of embodiments of the present invention to provide an airborne wind energy system that can be launched to a higher height without the need for a correspondingly long cable.

According to a first aspect, the present invention provides a method of disassembling a wind turbine and erecting a wind energy generating system, said wind turbine comprising a tower placed on a foundation of a wind turbine site and a nacelle having a rotor mounted on said tower, the method comprising the steps of:

removing at least the rotor from the wind turbine,

mounting an aerial wind energy system for generating electrical power on a portion of the wind turbine via a cable; and

electrically connecting the airborne wind energy system to a power grid via a power transmission line.

Thus, the wind turbine being dismantled comprises a tower on which the nacelle and the rotor are mounted and which is placed on the foundation of the wind turbine site. The rotor, including at least the blades of the wind turbine, is disassembled and removed. This may be due to, for example, blade wear or damage, or to insufficient energy output by the wind turbine. The method also includes connecting the airborne wind energy system to a portion of the wind turbine via a cable. For example, to a wind turbine tower, to a base frame of a nacelle, to a wind turbine foundation, etc. Thus, the airborne wind energy system is mechanically attached to the wind turbine by means of a cable. Further, the airborne wind energy system is electrically connected to the grid via a transmission line. Thus, an airborne wind energy system generates electrical energy for an electrical grid by converting the energy of the wind into electrical energy substantially in the manner described above.

In this context, an "airborne wind energy system" is defined as a system comprising a ground station and a portion that is launched to a height higher than the ground station and capable of capturing wind energy. The ground station and the part transmitted to a higher level are connected by a cable. The collected energy is transferred to the ground station in the form of mechanical energy or in the form of electrical energy. The ground station need not be on the ground but rather closer to the ground than the portion to be launched to a higher elevation.

In this way, the erected wind energy generating system according to the invention comprises at least a part of the previous wind turbine in addition to the airborne wind energy system mounted to the wind turbine tower via cables. In this way, the airborne wind energy system has been retrofitted to a wind turbine from which at least the rotor has been removed.

Thereby, no new site for installing the airborne wind energy system is required. Alternatively, the site that has been allocated for the wind turbine is reused for accommodating the airborne wind energy system. In this way, energy production is maintained for the grid on the site after the wind turbine is shut down. Furthermore, by using an already existing wind turbine site, the energy generated by the airborne wind energy system can be built relatively quickly and at relatively low cost.

Thereby, at least the foundation of the previous wind turbine is advantageously reused. Since wind turbine towers and foundations used to ground the towers are typically generally sized to withstand greater loads and vibrations than the airborne wind energy system, the wind turbine towers and foundations may generally be reused directly for the airborne wind energy system without any significant modification or alteration. In certain situations, this may further result in that any regulatory or safety approval for the newly used tower may be obtained relatively easily and quickly.

Advantageously, only the rotor of the previous wind turbine is removed. Thereby, the dismantling and removal of components of previous wind turbines is reduced to a minimum, so that the aerial energy system can be installed ready for relatively fast operation at relatively low cost. In addition, this provides the possibility to reuse components of the wind turbine in the wind power system, for example for mechanically connecting or carrying the airborne wind energy system and/or for converting or otherwise handling the energy output from the airborne wind energy before being directed to the grid. This may include reusing one or more parts of, for example, a nacelle, a bedplate or main frame of the wind turbine, a wind turbine converter, a control system, a yaw system, different electrical components, a main shaft and a gearbox of the wind turbine. In an embodiment, the step of installing the airborne wind energy system is performed by mechanically connecting the cable to a main shaft of the wind turbine. Thus, according to this embodiment, the energy transferred from the part of the airborne wind energy system that is emitted to a higher level is in the form of mechanical energy. This mechanical energy is provided to the main shaft of the wind turbine and thereby supplied to the generator of the wind turbine, parts of which are thereby advantageously reused.

In other embodiments of the invention, the method further comprises removing at least the nacelle from the wind turbine and installing the airborne wind energy system on at least a portion of the wind turbine tower.

Generally, reusing at least a part or all of a wind turbine tower (with or without parts of the wind turbine nacelle) is advantageous, inter alia, in that hereby the nacelle wind energy system can be launched and operated from a considerable height. Conventional wind turbine towers are often in the order of about 80-120 meters or even higher for more modern wind turbine types, so that even if one or more tower sections are disassembled, a considerable height for operating the airborne wind energy system is achieved. In this way, when one end of the cable is mounted on the tower, the length of the cable required in order to position the launched part of the airborne wind energy system at a suitable height is substantially reduced compared to a situation where the cable is attached at a position at or near the ground. Since such cables are heavy in addition to being expensive, the weight is also reduced in addition to reducing the cost of the cable, particularly in the case where the cable needs to be electrically conductive in addition to being mechanically resistant.

Additionally, mounting one end of the cable at the wind turbine tower or nacelle improves launch and landing/recovery conditions of the airborne wind energy system. For example, the airborne wind energy system will quickly avoid any surrounding obstacles such as trees, buildings, etc., thereby reducing the risk of collision between the airborne energy system and any surrounding objects. In this way, the wind turbine tower provides a safer launch and landing site for the airborne wind energy system.

Cable with a flexible connectionMay be electrically conductive. In this case, the cable may be configured for transmitting power in the form of AC current or DC current and/or for transmitting communication signals. As an alternative, the cable may be configured only for mechanically attaching the airborne wind energy system to the wind turbine, and not for sending electrical current. In this case, the cable may for example take the form of a rope, wire or the like. The cable may be at least partially made of a durable material (e.g., such as

Such synthetic fiber materials). In this case, the cable may for example be able to handle the expected tensile loads from the airborne wind energy system. For example, the cable may comprise a conductive core surrounded by a synthetic fiber material, thereby providing a cable that is electrically conductive in addition to being durable. Furthermore, the wind energy production system according to the invention is advantageous in that at least some of the facilities of the wind turbine, in particular the foundation and the power lines connecting the site to the grid, are reused. This may also include, for example, roads, service equipment, etc.

In an embodiment, the method further comprises removing at least the nacelle and the tower from the wind turbine and mounting the airborne wind energy system on the base of the wind turbine tower. Thereby, as mentioned above, the foundation dimensioned to support the wind turbine and thereby certainly being able to withstand loads from the airborne wind energy system is advantageously reused. Thereby, the wind turbine foundation does not need to be removed. In addition, the infrastructure and surroundings that are already ready for the wind energy system are advantageously reused. In particular, the connection to the grid is already in place for the wind turbine site and the connection of the airborne wind energy system to the grid can be established quickly and at low cost. Furthermore, it is ensured that there are no obstacles around or remain free for the wind energy system and that the infrastructure is in place for maintenance or repair.

According to an embodiment of the invention, the step of mounting the airborne wind energy system is performed by mounting a platform carrying the airborne wind energy system on a wind turbine yaw bearing. Thereby, the airborne wind energy system is mounted on the wind turbine via the yaw bearing of the wind turbine. Thus, the airborne wind energy system is reused and re-adapted to the yaw system of the previous wind turbine, which may always be used to orient the wind energy generating system with respect to the oncoming wind, thereby directing the airborne wind energy system into the wind. This may be obtained, for example, by mounting the cables on some kind of platform mounted on a yaw bearing, the cables thus being mounted on an airborne wind energy system, thereby rotating together with the platform as it performs a yaw movement. Thereby, the risk of severe damage of the cables is reduced, since the cables are automatically guided from the platform at an optimal or near optimal angle with respect to the wind.

The platform may be any kind of structure adapted to connect cables of the airborne wind energy system and optionally for carrying the airborne parts of the airborne wind energy system when not in operation.

In an embodiment, the method according to the invention further comprises the step of removing at least one tower section of the wind turbine tower. Further, the step of installing the airborne wind energy system is performed by mounting a platform carrying the airborne wind energy system on the tower flange. Thereby, only parts of the wind turbine tower or some of the tower sections are reused for the airborne wind energy system. In this way it is ensured that the remaining tower can withstand higher loads and is less sensitive to vibrations from the airborne wind energy system than the original wind turbine tower of greater height. In addition, the complexity and time required to install the airborne wind energy system is thereby reduced. The tower flange advantageously provides a suitable means of coupling and mounting the platform using, for example, bolt shafts or threaded openings of the tower flange.

In an embodiment, the method further comprises the step of electrically connecting the airborne wind energy system to a power line previously used for electrically connecting the wind turbine to the grid. According to this embodiment, the electrical energy generated by the airborne wind energy system is supplied to the grid via the power lines of the wind turbine, thereby reusing the power lines already in place and putting the wind turbine into operation. Thereby, there is no need to establish new transmission lines for the aerial wind energy system to generate electricity for the grid, whereby the production of the aerial wind energy system can be made significantly faster and at a significantly lower cost.

The airborne wind energy system may comprise at least one airborne generator, i.e. the airborne generator is comprised in the part of the airborne wind energy system that is launched to a higher altitude. Thus, the energy collected by the airborne wind energy system from the wind is converted into electrical energy at a higher altitude and transferred in the form of electrical energy towards the ground. Thus, an electrically conductive connection is required between the aerial part of the aerial wind energy system and the power transmission line. For example, the cable may be made of a conductive material. Alternatively, a separate electrically conductive cable may be provided.

Alternatively, the airborne wind energy system may comprise at least one generator arranged on a wind turbine tower. According to this embodiment, the energy collected by the airborne wind energy system from the wind is transferred in the form of mechanical energy towards the ground and supplied to a generator arranged on the tower of the wind turbine. As a further alternative, the individual generators of the airborne wind energy system may be provided at any other suitable location, such as within or near the tower of the wind turbine and/or within or near the foundation.

In an embodiment, the step of connecting the airborne wind energy system to the power transmission line comprises electrically connecting the airborne wind energy system to a transformer of the wind turbine. According to this embodiment, the electrical energy originating from the airborne wind energy system is provided to the power lines of the wind turbine via the transformer of the wind turbine. Thereby, the airborne wind energy system does not require a new transformer and the transformer of the wind turbine can be reused. This results in a reduction in installation costs.

In an embodiment, the aerial wind energy system is mounted to the wind turbine tower via a mounting base that is rotatably connected to a portion of the wind turbine. According to this embodiment, in addition to the movement of the wind turbine yaw system, the mounting base and thus the airborne wind energy system is allowed to perform small rotational movements relative to the tower. Thus, even if the airborne wind energy system is directed towards the oncoming wind, for example by means of the yaw system of the wind turbine, it may still be moved slightly away from this position by allowing the mounting base to rotate slightly. This is for example advantageous in case the airborne wind energy system belongs to the kind comprising kites, gliders or similar devices following a crosswind (crosswind) flight path (e.g. "figure 8") while generating electrical energy.

Alternatively, the cables may be mounted directly on the wind turbine tower or directly on the yaw bearing or nacelle.

In an embodiment, the method further comprises the step of positioning at least a part of the airborne wind energy system within the wind turbine tower and/or within the nacelle of the wind turbine (if not disassembled). The part of the airborne wind energy system may be located, for example, within the wind turbine tower and/or within the nacelle of the wind turbine when not in operation. Thus, the wind turbine tower and nacelle may also be used as a storage house for the airborne wind energy system, resulting in some protection of the system against the weather, thereby reducing wear on the system. When not in operation, the part of the airborne wind energy system that will be fully or partially within the tower or nacelle may for example comprise the airborne part of the system (i.e. kite, glider or similar) and optionally cables. In an embodiment, the entire nacelle wind energy system is positioned within a wind turbine tower wall, e.g. on a platform within the tower.

According to a second aspect, the present invention provides a wind energy generating system comprising at least a portion of a wind turbine on a foundation on a wind turbine site and an airborne wind energy system for generating electrical energy for an electrical grid, the airborne wind energy system being coupled to the portion of the wind turbine via a cable and a wind turbine yaw bearing operated by a motor, the airborne wind energy system further being electrically connected to the electrical grid via a power transmission line. Thus, the wind energy generating system comprises an airborne wind energy system coupled to and retrofitted to a portion of a previous wind turbine (or in other words, to a remaining portion of the previous wind turbine where at least the rotor has been dismounted or otherwise removed). The advantages of the above described method are described.

In an embodiment, the airborne wind energy system is coupled to at least a portion of a wind turbine tower via a platform.

The airborne wind energy system is coupled to the portion of the wind turbine via a wind turbine yaw bearing operated by a motor. The wind energy generating system may further comprise a control system for controlling the electric motor. By controlling the motor, the yaw bearing may be operated fully or partly as on previous wind turbines to perform a yaw movement, thereby rotating the attachment point of the cable in the direction of the wind. The attachment point may be anywhere above or on the nacelle or the yaw bearing, such that the attachment point is rotatable with respect to the tower.

In an embodiment, the airborne wind energy system is electrically connected to a power line previously used for electrically connecting the wind turbine to the grid.

In an embodiment, the airborne wind energy system is electrically connected to the transmission line via a wind turbine transformer.

In an embodiment, the airborne wind energy system comprises at least one airborne generator.

In an embodiment, the airborne wind energy system comprises at least one generator at or near the wind turbine tower.

In one embodiment, the wind energy generating system may comprise a control structure configured to control movement of the portion of the airborne wind energy system that is launched to a higher altitude.

It will be appreciated that the control system for controlling the electric motor and the control structure for controlling the airborne wind energy system described above may be two separate systems. However, in one embodiment, one of the control structure and the control system may be a subsystem of the other of the control structure and the control system. The control structure and control system may also be integrated in the same computer system. The control structure and the control system may operate independently of each other.

In one embodiment, the control structure may be configured to execute a predetermined movement pattern that effects rotational movement (i.e., 360 degree movement) of the airborne wind energy system. This rotational movement may be the same consistent meaning as the previous rotation, or it may be inconsistent; that is, each rotation may follow another path than the previous rotation. The rotation may be, for example, circular, elliptical, wavy, etc., while still creating rotational movement.

In one embodiment, the rotational movement may be substantially circular.

Drawings

The invention will now be described in more detail with reference to the accompanying drawings, in which:

figure 1 is a sketch of a wind turbine being dismounted,

FIG. 2 is a sketch of an adaptation of an airborne wind energy system to a wind turbine tower according to an embodiment of the invention, FIGS. 3 and 4 are perspective views of two airborne wind energy systems for use in a wind energy generating system according to an embodiment of the invention,

figures 5 and 6 illustrate airborne wind energy generation systems according to two embodiments of the present invention,

figures 7 and 8 illustrate the operation of a wind energy generating system according to an embodiment of the present invention,

figure 9 illustrates mounting of an airborne wind energy system on a platform mounted on a wind turbine yaw bearing,

figure 10 illustrates the mounting of an airborne wind energy system on a wind turbine tower according to an embodiment of the present invention,

FIGS. 11 to 13 illustrate another embodiment of mounting an airborne wind energy system on a nacelle of a wind turbine, an

FIGS. 14-16 illustrate wind energy generating systems according to three embodiments of the present invention.

Detailed Description

Fig. 1 illustrates a wind turbine 1 partially disassembled in preparation for reuse of the wind turbine tower for retrofitting an airborne wind energy system. Here, the nacelle (not shown) has been removed, the first tower section 2a is being removed from the wind turbine (hanging from the crane 3), leaving in place two or more tower sections 2b arranged on the base of the wind turbine site. Thereby, the remaining one or more tower sections 2b terminate in a tower flange 4, which tower flange 4 can advantageously be used for mounting an airborne wind energy system. Alternatively, only the rotor of the wind turbine may be disassembled and the airborne wind energy system retrofitted to the rest of the wind turbine.

Fig. 2 illustrates a method for disassembling a wind turbine 1 and erecting a wind energy generation system 100 according to the invention. The wind energy generation system comprises at least a part of a wind turbine tower 2b arranged on a foundation 5 of a wind turbine site and an airborne wind energy system 200 mounted on the tower 2b or another part of the remaining wind turbines for generating electrical energy for a power grid. The airborne wind energy system 200 is electrically connected to the grid via a transmission line 201. The power line may be coupled to a transformer of the wind turbine, or to a power line of the wind turbine (previously used for electrically connecting the wind turbine to the grid), or may be separate therefrom. In this way, at least one or more of wind turbine foundation 5 and wind turbine tower section 2b have been reused for the erected wind energy generating system 100 comprising the airborne wind energy generating system 200. Other parts from the wind turbine may be reused and form part of the erected wind energy generation system 100 (such as the nacelle, the main frame, the main shaft, the yaw bearing, the converter, the transformer and/or the transmission line of the wind turbine).

In FIG. 2, the mounting of a platform 202 carrying an airborne wind energy system 200 to a wind turbine tower 2b is illustrated. The platform may for example be mounted on a wind turbine yaw bearing (not shown), on a main frame of a wind turbine nacelle (not shown) or on a tower flange 4.

In FIG. 2, an airborne wind energy system 200 for generating electrical energy is outlined as including a glider 13, sometimes also referred to as Makani. This will be described in more detail later. The airborne wind energy system 200 for generating electrical energy may likewise comprise a kite as described with respect to the following figures. In all embodiments, the airborne wind energy system 200 is mechanically coupled to the wind turbine tower and (for certain types of airborne wind energy systems) is also electrically coupled to the wind turbine tower via a cable 6 (see later figures).

Fig. 3 is a perspective view of an airborne wind energy system in the form of a kite 12 comprising a kite for use in a wind energy generation system according to an embodiment of the present invention. The kite 12 catches wind and moves thereby. This causes the cables 6 attached to the kite 12 to be extracted or retracted, thereby generating mechanical energy. This mechanical energy is transferred to a generator positioned on a ground station, which may be positioned at the top of the remaining wind turbine tower or on the ground, which in turn is electrically coupled to the transmission line and optionally to the grid via a wind turbine converter and/or transformer.

FIG. 4 is a perspective view of an alternative airborne wind energy system in the form of a glider 13, also sometimes referred to as Makani, for use in a wind energy generating system according to an embodiment of the present invention. The glider 13 is provided with a plurality of rotors 14, each of which is capable of extracting energy from the wind and producing electrical energy. The generated electrical energy is transferred from the glider by means of an electrically conductive cable 6. The cable 6 may be electrically connected to a transformer positioned on a ground station or near the wind turbine tower, which in turn is electrically coupled to the transmission line and optionally to the grid via a wind turbine converter and/or transformer.

Fig. 5 illustrates the operation of the kite 12 of fig. 3. It can be seen that wind acts on the kite 12 and moves the kite along a movement pattern. For example, the kite 12 may be extracted along a substantially linear path, then retracted while moving along a movement pattern having a figure-of-eight shape as indicated by the dashed lines. During the linear movement of the kite 12, the mechanical energy may be transferred to elements arranged at the attachment points of the ground station 15 on the platform 202, thereby causing the generation of electrical energy, for example in the manner described above with reference to fig. 2 to 3. During the subsequent retraction of the kite 12, energy may be consumed. However, the energy consumed is expected to be less than the energy generated during the linear movement of the kite 12. The kite 12 is thus mechanically connected to the platform and to the tower 2b of the wind turbine, thereby advantageously being launched from and retracted to a height considerably above the ground.

Fig. 6 illustrates the operation of the glider 13 of fig. 4. It can be seen that wind acts on the glider 13 and causes the glider 13 to move along a generally circular pattern of movement as indicated by the dashed lines. This movement of the glider 13 causes the rotor 14 to rotate, thereby generating electrical energy. The electrical energy is transferred via the electrically conductive cable 6 to a suitable electrical component (e.g. a transformer or converter unit) arranged at the attachment point of the ground station 15 on the platform 202. Like the kite of fig. 5, the glider 13 is thus mechanically connected to the platform 202 and to the tower 2b of the wind turbine, thereby advantageously being launched from and retracted to a height considerably above the ground.

In an alternative embodiment, the airborne wind energy system is connected to the base of the wind turbine and the wind turbine tower has been dismantled.

FIG. 7 illustrates the operation of the wind energy generating system 100 according to an embodiment of the present invention. In fig. 7, a plurality of wind energy generating systems 100 are shown, each wind energy generating system 100 comprising a wind turbine tower 2b of one or more tower sections placed on a wind turbine foundation 5 on a wind turbine site. The nacelle of each wind turbine has been removed and an airborne wind energy system 200 in the form of a kite 12 has been retrofitted to the wind turbine tower 2 b. In embodiments where the airborne wind energy system 200 has been mounted to a wind turbine yaw bearing, the kite 12 rotates in the direction of the wind, similar to what was done with previous wind turbine nacelles, and performs a yaw movement relative to the respective tower 2 b. Thereby, it is ensured that the kite 12 is launched directly into the wind. This reduces wear on the cable 6 and reduces the risk of cable breakage.

Because the airborne wind energy system is mounted on top of at least a portion of the wind turbine tower, cables are used considerably less and the kite 12 is launched to the desired higher height in a considerably shorter time.

The kite 12 is able to move along a prescribed path of movement, for example, as described above with reference to fig. 5. Thereby, mechanical energy is generated and transferred to the respective generator positioned on the respective wind turbine tower 2 b. It can also be seen that the kites 12 are in different positions along their pattern of movement. Thus, the kites 12 need not operate in a synchronized manner.

FIG. 8 illustrates the operation of the wind energy generating system 100 according to an embodiment of the present invention. The system is similar to that described with respect to fig. 7, only here is the airborne wind energy system 200 in the form of a glider 13. The glider 13 is capable of moving along a prescribed path of movement, for example, as described above with reference to fig. 6. Thereby, the rotor 14 of the glider 13 generates electrical energy, and the generated electrical energy is transferred via the electrically conductive cable 6 to the ground station on the respective wind turbine tower 2 b. Here, the electrical energy is supplied to a transformer or converter unit, for example, in the manner described above with reference to fig. 6.

In an embodiment, the assembly or farm of more wind turbine towers is equipped with different types of airborne wind energy systems (such as, for example, kites on the wind turbine tower alongside the wind turbine tower with gliders).

FIG. 9 illustrates mounting of an airborne wind energy system 200 on a platform 202 positioned on the wind turbine yaw bearing 18. The wind energy generating system thus comprises a wind turbine tower 2b placed on a foundation 5 of a wind turbine site and an airborne wind energy system 200 coupled to the wind turbine tower 2b via cables 6 and via a wind turbine yaw bearing 18. The airborne wind energy system 200 is also electrically connected to the grid via power transmission lines (not shown). In this manner, the yaw bearing 18 of the previous wind turbine is reused with the new wind energy generation system 100. The yaw bearing may operate fully or partially as on previous wind turbines to perform yaw movements, thereby rotating the platform 202 in the direction of the wind as illustrated by arrow 19. In this way, the attachment point 15 for the cable 6 of the airborne wind energy system is automatically oriented such that during operation of the kite or glider the cable is oriented in the same or almost the same direction as the platform.

FIG. 10 illustrates the mounting of an airborne wind energy system 200 on a platform 202 on a wind turbine tower according to an embodiment of the present invention. FIG. 10 a is a side view of the wind energy generating system 100 and FIG. 10 b is a top view of the wind energy generating system 100. The airborne wind energy system 200 is mounted via a cable 6 on a platform 202 on a wind turbine tower. Thus, if the platform is mounted on a wind turbine yaw bearing, the airborne wind energy system typically rotates with the platform 3 when the airborne wind energy system performs a yaw movement due to the yaw system. However, the cable 6 is attached to a mounting base 24, which mounting base 24 is rotatably connected to the platform 202. Thus, the attachment point of the cable 6 is allowed to rotate slightly relative to the platform 202. This may for example be advantageous when the airborne wind energy system is moved along a movement pattern, for example as described above with reference to fig. 5 and 6. In an embodiment, the platform may be formed by all or part of the wind turbine nacelle.

Fig. 11 to 13 illustrate another embodiment of mounting the airborne wind energy system 200 on a nacelle 1100 of a wind turbine. FIGS. 10 and 13 are side views of the wind energy generating system 100, and FIG. 12 is a top view of the wind energy generating system 100 of FIG. 11. The airborne wind energy system 200 is mechanically connected to the main shaft 1102 of the wind turbine via a cable 6 wound on a wire drum 1101 and unwound from the wire drum 1101. During operation, the kite 12 is extracted along a substantially linear path and subsequently retracted while moving along a movement pattern having a figure-of-eight shape, as indicated in fig. 5. During the cable extraction, the mechanical energy is then transferred to the stranded cable drum 1101, thereby being transferred to the wind turbine main shaft 1101, which generates energy. In fig. 11 and 12, the nacelle 1100 is illustrated as yawing relative to the direction V of the wind, such that the wind direction is substantially transverse to the axial direction of the nacelle and the main shaft (preferably substantially 90 degrees relative to this axial direction). Thereby, wear on the cable 6 is reduced. Alternatively or additionally, the stranded cable drum 1101 includes a guide member 1300 for guiding the wire relative to the drum axis, such as to reduce wear on the cable 6. In this way, the nacelle does not need to be yawed with respect to the wind direction.

FIG. 14 illustrates other embodiments of a wind energy generating system 100 according to the present invention. Here, the wind turbine rotor has been disassembled. The rotor is connected to the main shaft 1102 and the rotational movement of the rotor is thereby transmitted to the main shaft 1102. The main shaft 1102 is coupled to a generator (not shown) via a gear system (not shown). Thereby, the rotational movement of the main shaft 5 is converted into electrical energy by the generator. In this embodiment, an airborne wind energy system (not shown) is coupled to the nacelle 1100 of the wind turbine 1 via a cable 6. Thereby, the airborne wind energy system also reuses the yaw system of the previous wind turbine. The cable 6 is mechanically coupled to the main shaft 1102 by winding the cable 6 on an element 7 arranged around the main shaft 1102. Thus, withdrawing or retracting the cable 6 causes the element 7 to rotate. This rotation may be transferred to the main shaft 1102 for the generator to produce energy. According to this embodiment, the energy generated by the airborne wind energy system is transferred to the wind energy generating system 100 in the form of mechanical energy.

FIG. 15 illustrates a wind energy generating system 100 according to other embodiments of the present invention. In this embodiment, the cable 6 is wound on an element 7 coupled to the wind turbine gear system 8 via a rotating shaft 10. Thereby, the rotational movement of the element 7 due to the extraction or retraction of the cable 6 is transferred to the gear system 8, whereby the rotational speed of the input shaft of the generator 9 is increased. Therefore, similarly to the case described above with reference to fig. 14, the energy generation of the generator 9 is increased. Thus, in the embodiment of FIG. 15, the energy generated by the airborne wind energy system is also transferred to the wind energy generating system 100 in the form of mechanical energy, and the wind energy generating system reuses portions of the previous wind turbine including the gear system and generator in addition to the nacelle, wind turbine tower and base.

FIG. 16 illustrates a wind energy generating system 100 according to yet another embodiment of the present invention. In the embodiment of fig. 16, the cable 6 is electrically connected to the transformer 11 of the previous wind turbine. The transformer 11 may be connected to the power lines (not shown) of the previous wind turbine. Thus, the energy generated by the airborne wind energy system is transferred in the form of electrical energy to the ground station formed by the transformer, and thus the cable 6 needs to be electrically conductive.

Thus, also in this embodiment, parts of the previous wind turbine comprising the nacelle and the wind turbine transformer and optionally the transmission lines in addition to the wind turbine tower and the foundation are reused.