Power cable arrangement for offshore wind farms

Abstract

A power cable arrangement, in particular marine power cable, for offshore wind farms, including at least one cable drum device with a cable drum. The power cable arrangement includes at least one power cable wound on the cable drum with at least one cable end configured to pre-installing at a cable connection of a wind energy device. The power cable is wound on the cable drum such that a first section of the power cable is wound inversely to a further section of the power cable.

Claims

1. A power cable arrangement for offshore wind farms, comprising: at least one cable drum device with a cable drum, and at least one power cable wound on the cable drum and comprising at least one cable end configured to pre-installing on a cable connection of a wind energy device, wherein the power cable is wound on the cable drum such that a first section of the power cable is wound inversely to a further section of the power cable; and wherein the power cable drum includes at least one cable deflecting unit positioned away from a surface of the cable drum so as to allow overlapping of the at least one power cable wound on the cable drum between the surface of the cable drum and the at least one cable deflecting unit.

2. The power cable arrangement according to claim 1, wherein the at least one cable deflecting unit is configured to deflect the power cable during winding onto the cable drum such that the first section of the power cable is windable inversely to the further section of the power cable.

3. The power cable arrangement according to claim 2, wherein the cable deflecting unit comprises an arcuate cable guide.

4. The power cable arrangement according to claim 3, wherein the arcuate cable guide is a semicircular cable guide.

5. The power cable arrangement according to claim 4, wherein the radius of the semicircular cable guide is at least seven times larger than the diameter of the power cable, and/or the radius of the semicircular cable guide is at least greater than 50% of the cable drum radius.

6. The power cable arrangement according to claim 5, wherein the radius of the semicircular cable guide is at least greater than 75% of the cable drum radius.

7. The power cable arrangement according to claim 6, wherein the radius of the semicircular cable guide is at least greater than 90% of the cable drum radius.

8. The power cable arrangement according to claim 2, wherein the cable deflecting unit is attached to the cable drum device such that an arcuate cable guide runs in a plane parallel to a cable drum axis.

9. The power cable arrangement according to claim 2, wherein the cable deflecting unit is attached to the cable drum device by an articulation mechanism, wherein the articulation mechanism is movable at least between a first position, in which an arcuate cable guide extends in a plane parallel to a cable drum axis, and a second position in which the arcuate cable guide runs in a plane which has an angle of at least 45° to that of the plane parallel to the cable drum axis.

10. The power cable arrangement according to claim 9 wherein the articulation mechanism is movable at least between a first position, in which the arcuate cable guide extends in the plane parallel to the cable drum axis, and a second position in which the arcuate cable guide runs in the plane which has an angle of at least 75° to that of the plane parallel to the cable drum axis.

11. The power cable arrangement according to claim 10 wherein the articulation mechanism is movable at least between a first position, in which the arcuate cable guide extends in the plane parallel to the cable drum axis, and a second position in which the arcuate cable guide runs in the plane which has an angle of 90° to that of the plane running parallel to the cable drum axis.

12. The power cable arrangement according to claim 1, wherein the cable drum comprises a first cable drum section and a second cable drum section, wherein the first and second cable drum sections are freely rotatable relative to each other, and the first section of the power cable is wound on the first cable drum section, and the second section of the power cable is wound on the second cable drum section.

13. The power cable arrangement according to claim 1, wherein the cable drum device is formed as a floatable cable drum device.

14. A wind energy system, comprising: at least one wind energy device with at least one cable connection; and at least one power cable arrangement according to any one of the preceding claims, wherein a cable end of the power cable of the power cable arrangement is connected to the cable connection.

15. The wind energy system according to claim 14, wherein the wind energy system is an offshore wind energy system.

16. A method of installing an offshore wind farm having at least one offshore wind energy device, comprising: connecting at least one cable end of a power cable of a power cable arrangement according to claim 1 to a cable connection of the at least one offshore wind energy device, transporting the offshore wind energy device together with the power cable arrangement to an installation position of the offshore wind energy device, and unwinding the power cable.

17. The power cable arrangement according to claim 1, wherein the power cable arrangement is a submarine power cable arrangement.

18. A method of manufacturing a power cable arrangement according to claim 1, comprising: winding a first section of a power cable onto a cable drum in a first direction of rotation in a first winding step, and winding a further section of the power cable onto the cable drum in a direction of rotation opposite to the first direction of rotation in a further winding step which is at least downstream of the first winding step.

19. A cable drum device for a submarine power cable, comprising: a cable drum; and at least one cable deflecting unit configured to deflect the power cable during winding onto the cable drum such that a first section of the power cable is windable inversely to a further section of the power cable, the cable deflecting unit being positioned in a plane displaced from a surface of the cable drum to allow overlap of the power cable between the surface of the cable drum and the cable deflecting unit.

20. A method of manufacturing a power cable arrangement, comprising: winding a first section of a power cable onto a cable drum in a first direction of rotation in a first winding step, and winding a further section of the power cable onto the cable drum in a direction of rotation opposite to the first direction of rotation in a further winding step which is at least downstream of the first winding step, and wherein at least one of the steps of winding allows for an overlapping of the first section of the power cable and the second section of the power cable.

21. The method according to claim 20, wherein the method comprises: guiding the power cable over a cable deflecting unit mounted to the cable drum between the first winding step and the further winding step.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) There is now a multitude of possibilities for designing and further developing the power cable arrangement according to the application, the wind energy system according to the application, the cable drum device according to the application and the methods according to the application. For this purpose, reference is made on the one hand to the claims subordinate to the independent patent claims, and on the other hand to the description of embodiments in connection with the drawing. The drawing shows:

(2) FIG. 1 a schematic view of an embodiment of a power cable arrangement according to the present application,

(3) FIG. 2a a schematic view of a further embodiment of a power cable arrangement according to the present application,

(4) FIG. 2b a further schematic view of the embodiment of a power cable arrangement according to FIG. 2a,

(5) FIG. 3a a schematic view of a further embodiment of a power cable arrangement according to the present application with a cable deflecting unit in a second position,

(6) FIG. 3b a further schematic view of the embodiment of a power cable arrangement according to FIG. 3a with the cable deflecting unit in a first position,

(7) FIG. 4 a schematic view of a further embodiment of a power cable arrangement according to the present application,

(8) FIG. 5 a schematic view of an embodiment of an offshore wind energy system according to the present application,

(9) FIG. 6 a diagram of an embodiment of a method according to the present application, and

(10) FIG. 7 a diagram of an embodiment of a further method according to the present application.

(11) In the figures, the same reference signs are used for the same elements.

DETAILED DESCRIPTION OF THE INVENTION

(12) FIG. 1 shows a schematic view of an embodiment of a power cable arrangement 100 according to the present application comprising a cable drum device 102. In the present embodiment, the cable drum device 102 comprises a support member 106, for example in the form of a turntable 106, and a cable drum 104 supported thereon (for example rotatably).

(13) Furthermore, a wound up power cable 108, in particular a submarine power cable 108, is shown. It should be noted here that only a small number of windings are shown for the sake of clarity. In practice, a power cable may have a length of, for example, one kilometer.

(14) As can be seen, the power cable 108, preferably a medium voltage cable (e.g. for voltage between 10 kV and 155 kV) or a high voltage cable (for voltages up to 5 kV), comprises two (conventional) cable ends 110, 112. At least one cable end 110, 112, preferably both cable ends 110, 112, may be configured to pre-install the power cable 108 at a cable connection of a (not shown) wind energy device. Pre-installation means in particular that one cable end 110, 112 of the power cable 108 has already been mechanically and electrically coupled to a cable connection of the wind energy device, for example in a port, i.e. the cable has been terminated.

(15) In the present embodiment, the power cable 108 is divided into two sub-parts 114 and 116. In other words, the illustrated power cable 108 comprises a first section 114 and a further respectively second section 116. Preferably, the two sections 114, 116 may be substantially equal in length. In particular, the total length of the power cable 108 corresponds to the laying distance between two wind energy devices to be connected.

(16) The power cable 108 is wound on the cable drum 104 such that the first section 114 of the power cable 108 is wound in the opposite direction to the further section 116 of the power cable 108. In particular, a transition region 118 formed by a portion of the first section 114 and/or a portion of the further section 116 can be seen where the run of the power cable 108 is deflected by approximately 180°.

(17) It should be noted that the cable drum axis (in the illustrated stable state of the cable drum device 102) extends in the y-direction. In the present example, the y-direction corresponds to the vertical direction.

(18) The FIGS. 2a and 2b show schematic views of a further embodiment of a power cable arrangement 200 according to the present application with an embodiment of a cable drum device 202 according to the present application. In order to avoid repetitions, substantially only the differences from the previous embodiment are described below, and otherwise reference is made to the previous embodiment.

(19) In the present embodiment, the cable drum device 202 comprises at least one cable deflecting unit 220 configured to deflect the power cable 208 in such a way that the first section 214 of the power cable 208 is windable inversely to the further section 216 of the power cable 208. In the present case, the cable deflecting unit 220 comprises a substantially arcuate, preferably substantially semi-circular (e.g. between 150° and 210°) cable guide 222, which is mounted, in particular, via a connecting element 224 to the cable drum device 202, in the present case, in particular, directly to the cable drum 204. It shall be understood that, in other variants, the cable guide may also have other shapes, such as semi-oval shape, quarter-circular shape, etc.

(20) In particular, the power cable 208 may be guided along the outer arc, which in particular, is in the form of a U-section, of the cable guide 222. As can be seen, the power cable 208 is deflected (in a plane parallel to the cable drum axis 219) by approximately 180°. By this, it can be achieved in a simple manner that in a winding process the power cable 208 can be wound onto the cable drum 204 in such a way that the first section 214 of the power cable 208 can be wound in the opposite direction to the further section 216 of the power cable 208.

(21) As can be seen, the radius 226 of a substantially semi-circular cable guide 222 may be at least seven times larger than the diameter of the power cable 208. Alternatively or additionally, the radius 226 of a substantially semicircular cable guide 222 may be at least greater than 50% of the cable drum radius 228, preferably at least greater than 75% of the cable drum radius 228, more preferably at least greater than 90% of the cable drum radius 228.

(22) The illustrated cable drum device 202 may be floatable. For example, at least one floating body may be integrated in and/or form the support element 206 and/or the cable drum 204.

(23) The FIGS. 3a and 3b show schematic views of a further embodiment of a power cable arrangement 300 according to the present application with an embodiment of a cable drum device 302 according to the present application. In order to avoid repetitions, substantially only the differences from the previous embodiments are described below, and otherwise reference is made to the previous embodiments. In addition, it should be noted that for the sake of clarity, a power cable is not shown.

(24) In particular, the FIGS. 3a and 3b show a cable drum device 302 with a (foldable) cable deflecting unit 320 in a first position and location, respectively, and in a second position and location, respectively.

(25) In order to be able to adjust the cable deflecting unit 320 between the at least two positions and location, respectively, the cable deflecting unit 320 comprises a hinge mechanism 340. In particular, the arcuate guide 322 is mounted to the cable drum device 302 via the hinge mechanism 340 (and presently via the connecting element 324, which may also be omitted). In the present case, the cable deflecting device 320 is directly or immediately attached to the cable drum 304.

(26) In FIG. 3b, the cable deflecting unit 320 (and the hinge mechanism 340, respectively) is set or is located in the first position. In this first position, the arcuate cable guide 322 is located in a plane 330 (in this case, a vertical plane 330) parallel to the cable drum axis 319. In this position, a power cable can be deflected in a particularly simple manner, as previously described. Moreover, this position is also advantageous during transportation (with or without a power cable), since the cable drum device 302 is formed compactly in this position.

(27) From this first position, the cable deflecting unit 320 (and the hinge mechanism 340, respectively) can be set into a second position. In particular, the cable deflecting unit 320 and the hinge mechanism 340, respectively, is movable into the second position in which the substantially arcuate, in particular substantially semicircular, cable guide 322 extends in a plane 332 having an angle 333 of at least 45° to the plane 330 extending parallel to the cable drum axis 319, preferably of at least 75°, in particular preferably of substantially 90°, as exemplified shown in FIG. 3a.

(28) In particular, in this position the cable deflecting unit 320 is folded away from the circumferential drum wall. The advantage of this position is that the winding of the power cable, in particular, of the first section, is not, or at least hardly, affected by the cable deflecting unit 320. The winding process can be facilitated.

(29) Furthermore, advantageously, at least one cable holder 346 is arranged on the cable drum 304 in the upper half of the cable drum 304 in order to be able to hold (and in particular guide) the deflected power cable 308 into the upper region of the cable drum 304.

(30) The FIG. 4 shows a schematic view of a further embodiment of a power cable arrangement 400 according to the present application with an embodiment of a cable drum device 402 according to the present application. In order to avoid repetitions, substantially only the differences from the previous embodiments are described below, and otherwise reference is made to the previous embodiments. In addition, it should be noted that for the sake of clarity, a power cable is not shown.

(31) The illustrated cable drum 404 comprises a first cable drum section 450 and a second respectively further cable drum section 452, wherein the first and second cable drum sections 450, 452 are freely rotatable relative to each other. The first section of the power cable may be wound on the first cable drum section 450. The second section of the power cable may be wound on the second cable drum section 452.

(32) In a particularly simple and reliable manner, unwinding of the power cable may be performed. For example, first the first section can be unwound by turning the first cable drum section 450 and then the further section can be unwound by turning the second cable drum section 452 (or vice versa). Simultaneous turning of the cable drum sections 450, 452 may also be performed.

(33) In particular, the cable drum 404 may be formed by a central tube structure 454 and two tube sections 450, 452 (e.g., in the form of two outer tubes 450, 452) arranged one above the other in the longitudinal axis direction 419 of the central tube structure 454 (e.g., in the form of an inner tube 454), which may be freely turned relative to each other. The power cable may be wound around the two outer tubes 450, 452 such that it winds around each tube 450, 452 with an opposite direction of rotation.

(34) Furthermore, a cable deflecting unit 420, for example according to FIG. 2 or FIG. 3, is arranged. In the present embodiment, the cable deflecting unit 420 is attached to the central tube structure 454.

(35) Preferably, the extension of the cable deflecting unit 420 in a direction along the cable drum axis 419 may substantially correspond to the length of the extension of a cable drum section 450, 452 (presently the first cable drum section 450) in the y-direction (presently the vertical direction). This further facilitates the winding process.

(36) The FIG. 5 shows a schematic view of an embodiment of an offshore wind energy system 560 according to the present application. In particular, the system 560 comprises a power cable arrangement 500, for example corresponding to an arrangement according to any of FIGS. 1 to 4.

(37) In addition to the power cable arrangement 500, the offshore wind energy system 560 in the present application comprises two offshore wind energy devices 562, 564 (e.g., two offshore wind turbines 562, 564). It shall be understood that in other variants of the application, only a single offshore wind energy device may be provided.

(38) The offshore wind energy system 560 is shown in a pre-installed state. In this state, at least a first cable end 510 is mechanically and electrically coupled to a cable connection 568 (e.g., a control cabinet) of the first offshore wind energy device 564. Furthermore, in the present embodiment, the further cable end 512 is mechanically and electrically coupled to a cable connection 566 (e.g., a control cabinet) of the further offshore wind energy device 562. Moreover, in this embodiment, the power cable 508 is wound on the cable drum 504.

(39) As can be further seen, the illustrated elements 500, 562, 564 are floatable. The reference sign 570 denotes the water surface.

(40) In this pre-installed state, the offshore wind energy system 560 can be transported to a specific installation location, for example by a tugboat. There, for example, the first offshore wind energy device 564 may first be anchored. Then, the second offshore wind energy device 562 can be transported to its installation location while simultaneously unwinding the power cable from the cable drum device 502. The installation process can be significantly simplified.

(41) The FIG. 6 shows a diagram of an embodiment of a method according to the present application. For example, the method may be used to manufacture a power cable arrangement according to any of FIGS. 1 to 4.

(42) In the method, in particular in the winding process, a first section of the power cable (of at most two sections) is wound onto the cable drum with a first direction of rotation and winding direction, respectively, in a first winding step 601. The further section of the power cable is wound onto the cable drum with a direction of rotation and winding direction, respectively, opposite to the first direction of rotation in a further winding step 603.

(43) In step 602, a deflecting of the power cable occurs, for example, using a previously described cable deflecting unit. It shall be understood that a part of the first section and/or a part of the further section can run over the cable deflecting unit.

(44) The FIG. 7 shows a diagram of an embodiment of a further method according to the present application. The method may be used for installing an offshore wind energy system, as exemplified shown in FIG. 5.

(45) In a first step 701, a connecting of at least one cable end of a power cable of a previously described power cable arrangement to a cable connection of the at least one offshore wind energy device is performed. In a further step 702, a transporting of the offshore wind energy device together with the power cable arrangement to an installation position of the offshore wind energy device is performed. In a further step 703, an unwinding of the power cable is performed.

(46) In particular, the method comprises a previously described pre-installing of an offshore wind energy device, wherein, for example, in a port, at least one cable end of a power cable of a previously described power cable arrangement is mechanically and electrically coupled to a cable connection of the at least one offshore wind energy device (step 701).

(47) After the pre-installation, the offshore wind energy device together with the (for example floatable power cable arrangement) can be transported, in particular towed, for example, by a ship, to the installation site (step 702).

(48) At the installation site, the power cable may then be unwound in the manner previously described (step 703), and, if the further cable end is not yet connected, in particular, pre-installed at a further wind energy device, the further cable can be connected to a cable connection of a further wind energy device.

(49) All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

(50) The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

(51) Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.