Patent Application
20230184228
This application claims priority to EP Application No. 21214654.2, having a filing date of Dec. 15, 2021, the entire contents of which are hereby incorporated by reference.
The following relates to a wind turbine.
A wind turbine is an apparatus to convert the wind's kinetic energy into electrical energy. The wind turbine comprises, for example, a rotor having one or more blades, a nacelle including a generator, converter and transformer and a tower holding, at its top end, the nacelle. The tower of the wind turbine may be connected, via a transition piece, to a foundation of the wind turbine, such as, but not limited to, a monopile in a seabed.
The transformer in the nacelle and a further high voltage component, such as a switch gear, in the wind turbine tower bottom or foundation are connected via a high-voltage (HV) cable arrangement. So far, the HV cable arrangement has been installed in one piece constituting one full cable length. As the wind turbines and their towers are increasing their size, installation of a full-length cable after having erected the tower is becoming more complicated.
The tower of a wind turbine is nowadays composed of a plurality of tower sections. JP 2010-268 595 A suggests to divide the HV cable arrangement into a plurality of cable arrangement segments corresponding to the plurality of tower sections. Respective two of the cable arrangement segments are connected by a cable connection portion arranged near the connection portion of the adjacent tower sections. Such, the method for lying the HV cable in the tower of the wind turbine becomes easier.
An aspect relates to provide a wind turbine that enables an easy installation of a cable arrangement in a tower which where the cable connection portion has improved properties.
According to embodiments of the invention, a wind turbine is provided comprising a tower composed of a plurality of tower sections. The number of tower sections may be two or more but is, in general, arbitrary. An upper section on top of the tower has a nacelle and a rotor with rotor blades. The rotor is attached to the nacelle and the rotor blades are rotatable by wind around a horizontal rotor axis to drive a generator in the nacelle. The generator is connected to the transformer via a converter.
A high voltage (HV) cable arrangement is laid in the tower and connects a first HV component, such as the transformer, in the nacelle and a second HV component, such as a switch gear, in the wind turbine tower bottom or foundation. The HV cable arrangement is divided into a plurality of cable arrangement segments corresponding to the plurality of tower sections. Respective two of the cable arrangement segments are connected via a cable connection device such that a plurality of cable arrangement segments is connected in series to constitute the HV cable arrangement.
The phrase “the HV cable arrangement being divided into a plurality of cable arrangement segments corresponding to the plurality of tower sections” is to be understood that a cable arrangement segment is provided within a respective tower section. However, to connect the first HV component and the second HV component via the plurality of cable arrangement segments, the number of cable arrangement segments and the number of tower sections may vary by one to connect the first HV component in the nacelle to the cable connection device located in, but not limited to, the topmost of the tower sections.
According to embodiments of the invention, the cable connection device comprises a plate-based shielding.
According to embodiments of the invention, the wind turbine tower and the cable arrangement are divided into a respective number of tower sections allowing for pre-installation of the cable arrangement segments and thus enabling fast assembly when desired. The pre-assembled structures may then be transported to the final construction site, e.g. an offshore wind park consisting of a plurality of wind turbines. The final tower installation can then take place offshore, thereby connecting free ends of the cable arrangement segments to assigned cable connection devices.
One the one hand, the plate-based shielding facilitates the final installation of the cable arrangement segments. On the other hand, the plate-based shielding provides a safe shield in the event of an arc flash accident during operation. Though, the plate-based shielding enables access to the HV components inside the cable connection device and allows for controlling the effects of faults inside the cable connection device.
According to a preferred embodiment, the cable connection device has a cabinet composed of a bottom panel, at least one side wall, and a top panel. Thus, the cable connection device may be a metal plate-based box.
The cabinet is closed on all sides and has at least one maintenance door or flap for having access to its interior. The maintenance door may be realized at the top panel and/or at least one of the side walls.
According to a further preferred embodiment, the cabinet, though being a closed casing, comprises a pressure release mechanism. The pressure release mechanism may be in the bottom of the panel. Placing the pressure release mechanism in the bottom panel enables for an arc flash blast to be directed in a specified direction of the tower section being located below the cable connection device. Since no further platform is typically located below the platform on which the cabinet is provided, there is a huge volume of air in tower section below to which the energy can be released. Consequently, there is no or significantly reduced danger of injury for people being in the tower section below.
For example, the pressure release mechanism comprises a perforated plate and/or an explosion hatch and/or a relief of overpressure.
According to a further preferred embodiment, the cabinet of the cable connection device comprises a first cable bushing through which a first cable arrangement segment is guided into the interior of the cable connection device and a second cable bushing through which a second cable arrangement segment is guided into the interior of the cable connection device. The first cable arrangement segment and the second cable arrangement segment are vertically connected with each other using an end termination within the cable connection device. This embodiment allows to guide two cable segments to enter the interior of the cable connection device in a specified way. The connection between the free ends of the cable arrangement segments takes place inside the cable connection device by means of end terminations which can be of a conventional type.
The first and the second cable bushings may be provided in the same side panel of the cabinet. Alternatively, they may be provided in different side panels of the cabinet.
According to a further preferred embodiment, the HV cable arrangement and each of the cable arrangement segments comprises a multi-phase cable, where all phases of respective two of the multi-phase cables are connected via the cable connection device.
Alternatively, the HV cable arrangement and at least some of the cable arrangement segments comprise a plurality of single-phase cables, where each phase of respective two of the single-phase cables are connected via a respective cable connection device. According to this embodiment, one cable connection device per phase may be provided. Alternatively, respective bushings for each phase of the respective two of the single-phase cables are provided to a single cabinet.
According to a further preferred embodiment, each of the tower sections has an upper flange and a lower flange, the upper flange of a first tower section and the lower flange of a second tower section being fixed to each other thereby providing a platform in the tower, where a cable connection device is located on the platform. The platform may be placed adjacent to the upper flange thereby allowing a worker to bolt the corresponding tower sections to each other when assembling the tower. However, the platform may be located adjacent to the lower flange as well.
According to a further preferred embodiment, the platform has one or more openings corresponding to the pressure release mechanism of the bottom panel. This allows for an arc flash blast to be directed in a specified direction in the area below the cable connection device, i.e. the tower section below.
Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein
In the figures, like reference numerals designate like or functionally equivalent elements, unless otherwise indicated.
The tower 4 is erected on a monopile 6 or any other type of foundation which is driven into a seabed 7 and is partly above the level of seawater 8. The monopile 6 constitutes a foundation of the wind turbine. The tower 4 may be connected, via a transition piece (not shown), to the foundation of the wind turbine.
The tower 4 comprises a plurality of sections 11, 12, 13, 14. In the present example, the tower 4 comprises a bottom tower section 11, two middle tower sections 12, 13, and a top tower section 14. By way of example only, the number of tower section corresponds to four. However, the number of tower sections may be higher or lower. The tower sections 11, 12, 13, 14 include each one or more upper flanges 15u bolted to a corresponding lower flange 15l of another tower section 11, 12, 13, 14. Further, the bottom tower section 11 of the tower 4 includes a flange 16 connected with the monopile 6.
The tower 4 comprises inside one or more platforms 17, 18, 19, 20. The platforms 17, 18, 19, 20 may be bolt platforms configured for a worker to bolt the corresponding tower sections 11, 12, 13, 14 to each other, as well as to the nacelle 3 and the monopile 6 when assembling the tower 4.
The transformer 5 constituting a first high voltage (HV) component is electrically connected to a second high voltage (HV) component (not shown) in the tower bottom or foundation of the wind turbine 1 by means of a HV cable arrangement 21. The HV cable arrangement 21 is divided into a plurality of cable arrangement segments 22, 23, 24, 25, 26. In the present embodiment, the plurality of cable arrangement segments 22, 23, 24, 25, 26 corresponds to the plurality of tower sections 11, 12, 13, 14 plus one as the transformer is placed within the nacelle 3 on top of the tower 4. However, the plurality of cable arrangement segments 22, 23, 24, 25, 26 can be less than the plurality of tower sections 11, 12, 13, 14.
Respective two of the cable arrangement segments 22, 23, 24, 25, 26 are connected via a cable connection device 27, 28, 29, 30 to each other. Each of the cable connection devices 27, 28, 29, 30 is located on a respective platform of the platforms 17, 18, 19, 20 such that the plurality of cable arrangement segments 22, 23, 24, 25, 26 is connected in series to constitute the HV cable arrangement 21 within the tower 4.
In the present example, the HV cable arrangement 21 and each of the cable arrangement segments 22, 23, 24, 25, 26 are a multi-phase cable, where all phases of respective two of the multi-phase cables are connected via the cable connection device 27, 28, 29, 30. Alternatively, and not illustrated in the figures, the HV cable arrangement 21 and each or a number of the cable arrangement segments 22, 23, 24, 25, 26 may comprise a plurality of single-phase cables, where each phase of respective two of the single-phase cables are connected via one or more respective cable connection devices.
Each of the cable connection devices 27, 28, 29, 30 comprises a plate-based shielding shaped as a metal plate-based box as illustrated in
As can be seen from the perspective view of
The cabinet 31 comprises a first cable bushing 41 and a second cable bushing 42. The first and second cable bushings are, by way of example only, arranged in the side panel 34. As can be seen from the side view of
As can be seen from
The platform 17, 18, 19, 20 has one or more openings in the area where the cabinet 31 and its bottom plate 32, respectively, are arranged. The bottom panel 32 comprises a pressure release mechanism 40 which can be seen from the bottom view of
The pressure release mechanism 40 may be in the form of a perforated plate as shown in
In event of an arc flash blast, this can be directed in a direction below the cable connection device 27. As the platform 17 is in the upper portion of the tower section 11, there is enough space within the tower section 11 through which the energy can be released without damaging components or causing danger to people being within the tower section 11.
As can be seen from the perspective views of
The plate-based casing 31 facilitates the final installation of the HV cable arrangement 21 and provides a safe shield in the event of an arc flash accident during operation. The shielding of the cabinet 31 (casing) prevents access to the parts inside the cabinet 31, prevents against mechanical impact from the outside and controls the effects of faults inside the cabinet 31.
While the present embodiments have two cable arrangement segments entering the cabinet 31, the number of cable arrangement segments entering the casing 31 may be chosen different therefrom.
The described configuration enables pre-installing the HV cable arrangement segments in one or more pre-assembled structured tower sections and merge those at a given destination, i.e., at the offshore installation site. As an advantage from the ability to pre-manufacturing, assembly and test of the HV cable installation in the required tower sections may be made in an early part of the supply chain where these procedures are less costly than on the final wind turbine installation site. The pre-installed cable arrangement segments in the cable connection device allows for fast, safe, and easy assembly of the cable arrangement.
The cable connection device provides the advantage of a safe operational environment around the facility and controls the safety risk in the event of an arc flash scenario. The cable connection device can be installed on one or more locations in the wind turbine structure. The cable connection device covers cable end terminations, as well as the complete cable breakout (cable bushings). This greatly reduces the risk of damaging the equipment during installation.
Thus, installation flexibility and reduced costs are provided with the suggested wind turbine.
Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.
For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21214654.2 | Dec 2021 | EP | regional |
