CONTROL SYSTEM FOR OPERATING A FLOATING WIND TURBINE UNDER SEA ICE CONDITIONS

Abstract

Provided is a control system for operating a floating wind turbine under sea ice conditions. The control system includes a detection device configured for detecting a formation of ice in a critical zone around the floating wind turbine, and an ice inhibiting device configured for manipulating the floating wind turbine in such a manner that the critical zone is free of a threshold amount of the detected formation of ice. Furthermore, a floating wind turbine is provided which includes a wind rotor including a wind rotor including a blade, a tower, a floating foundation, and an above-described control system. Additionally, a method for operating a floating wind turbine under sea ice conditions is provided.

Claims

1. A control system for operating a floating wind turbine under sea ice conditions, the control system comprising a detection device configured for detecting a formation of ice in a critical zone around the floating wind turbine, and an ice inhibiting device configured for manipulating the floating wind turbine in such a manner that the critical zone is free of a threshold amount of the detected formation of ice.

2. The control system according to claim 1, wherein the detection device comprises a vision-based detection device, particularly at least one of the group consisting of a camera, a light detection and ranging device, and a radio detection and ranging device.

3. The control system according to claim 1, wherein the detection device comprises a device configured for analysing a change in a dynamics of the floating wind turbine, particularly a change in a damped natural frequency of the floating wind turbine, caused by a change in at least one of the group consisting of a change in a mass property, a change in a damping property and a stiffness property.

4. The control system according to claim 1, wherein the detection device is configured for linking the formation of ice to a substructure of the floating wind turbine.

5. The control system according to claim 1, wherein the ice inhibiting device is configured for steering the floating wind turbine away from the formation of ice along a planned trajectory.

6. The control system according to claim 1, wherein the ice inhibiting device comprises at least one of the group consisting of an underwater propeller, a mooring line actuator, and an automatous underwater vehicle.

7. The control system according to claim 1, wherein the ice inhibiting device melts the formation of ice.

8. The control system according to claim 7, wherein the ice inhibiting device melts the formation of ice by heating a part of a substructure and/or a surrounding of the floating wind turbine.

9. The control system according to claim 1, wherein the ice inhibiting device comprises at least one of the group of an immersion heater and a thermoelectric generator.

10. The control system according to claim 1, wherein the ice inhibiting device is configured for breaking the formation of ice.

11. The control system according to claim 1, wherein the ice inhibiting device is configured for manipulating the floating wind turbine by manipulating at least one of the group consisting of a pitch, a roll, a yaw, a surge, a sway, and a heave of the floating wind turbine.

12. The control system according to claim 11, wherein the ice inhibiting device comprises at least one of the group of a floater pitch angle actuator, a mooring line actuator, an automatous underwater vehicle, and a blade pitch actuator.

13. A floating wind turbine comprising a wind rotor comprising a blade, a tower, a floating foundation, and the control system according to claim 1.

14. A method for operating a floating wind turbine under sea ice conditions, the method comprising detecting a formation of ice in a critical zone around the floating wind turbine, and manipulating the floating wind turbine in such a manner that the critical zone is free of a threshold amount of the detected formation of ice.

Description

BRIEF DESCRIPTION

[0074] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0075] FIG. 1 shows a floating wind turbine according to an exemplary embodiment of the present invention; and

[0076] FIG. 2 shows a floating wind turbine according to a further exemplary embodiment of the present invention.

DETAILED DESCRIPTION

[0077] The illustration in the drawing is schematic. It is noted that in different figures, similar or identical elements or features are provided with the same reference signs or with reference signs, which are different from the corresponding reference signs only within the first digit. In order to avoid unnecessary repetitions elements or features which have already been elucidated with respect to a previously described embodiment are not elucidated again at a later position of the description.

[0078] FIG. 1 shows a floating wind turbine 100 according to an exemplary embodiment of the present invention. The floating wind turbine 100 comprises three blades 140 attached to a hub forming a rotor mounted to a nacelle 160, a tower 130 and a floating foundation 120. The floating wind turbine 100 further comprises a plurality of mooring lines. Only a first mooring line 151 and a second mooring line 154 are shown in FIG. 1 for clarity reasons. The first mooring line 151 is fixed to the floating foundation 120 by a first mooring line fixation 152 and to a sea ground 113 by a second mooring line fixation 153. Further, the second mooring line 154 is fixed to the floating foundation 120 by a further first mooring line fixation 155 and to a sea ground 113 by a further second mooring line fixation 156.

[0079] The floating foundation 120 is fixed by the first mooring line 151 and the second mooring line 152 in such a manner that the floating foundation 120 is dunked in sea water 114 under a sea surface 112. Therefore, the floating foundation 120 is held under water by the mooring lines and/or the floating wind turbine's self-weight. A wind 111 acts on the three blades 140 of the rotor of the floating wind turbine 100 such that electrical energy may be generated by the floating wind turbine 100.

[0080] The floating wind turbine 100 floats in the sea water 114 and is held in position by the mooring lines, exemplarily illustrated by the first mooring line 151 and the second mooring line 154 in FIG. 1. Therefore, the floating wind turbine 100 has six individual degrees of freedom in which the floating wind turbine 100 may move. Namely, three translations a surge 103, a sway 102 and a heave 101, and three rotations a roll 106, a pitch 105 and a yaw 104.

[0081] Fixed to the nacelle 160 is a control system 170 which is a one-piece integrated control system 170. The control system 170 is shown schematically in FIG. 1 and is located in the nacelle 160.

[0082] FIG. 2 shows a floating wind turbine 200 according to a further exemplary embodiment of the present invention.

[0083] The floating wind turbine 200 comprises a floating foundation 220, a tower 230 mounted to the floating foundation 220, three blades 240 attached to a hub and mounted to a nacelle 260. The nacelle 260 is mounted to the tower 230 at the opposite end with respect to the floating foundation 220. The floating wind turbine 200 further comprises a plurality of mooring lines. Only a first mooring line 251 and a second mooring line 254 are shown in FIG. 2 for clarity reasons. The first mooring line 251 is fixed to the floating foundation 220 by a first mooring line fixation 252 and to a sea ground 213 by a second mooring line fixation 253. Further, the second mooring line 254 is fixed to the floating foundation 220 by a further first mooring line fixation 255 and to a sea ground 213 by a further second mooring line fixation 256.

[0084] The floating foundation 220 is fixed by the plurality of mooring lines, exemplarily illustrated as the first mooring line 251 and the second mooring line 252 in FIG. 2, in such a manner that the floating foundation 220 is dunked into the sea water 214 under a sea surface 212. A first formation of ice 271 and a second formation of ice 272 are each at least partially in a critical zone 205. The first formation of ice 271 and the second formation of ice 272 may for example each be an iceberg. The first formation of ice 271 comprises a first part 273 being located above the sea surface 212 and a second part 274 being located under the sea surface 212. Accordingly, the second formation of ice 272 comprises a further first part 275 being located above the sea surface 212 and a further second part 274 being located under the sea surface 212.

[0085] A detection device 281, particularly a vision-based detection device 281, particularly a camera 281, is mounted to the nacelle 260. The vision-based detection device 281 detects the first part 273 and the further first part 275 located above the sea surface 212 and being in the critical zone 205.

[0086] Additionally, a detection device 282, particularly a device 282 configured for analysing a change in a dynamic of the floating wind turbine 200, is mounted to the floating foundation 220. The detection device 282 may detect the second part 274 of the first formation of ice 271 and the further second part 276 of the second formation of ice 272 in the critical zone 205.

[0087] A first mooring line actuator 291 is mounted to the first mooring line 251 and a second mooring line actuator 294 is mounted to the second mooring line 294. As may be seen from FIG. 2 compared to FIG. 1, the floating foundation 220 is pulled deeper into the sea water 214 and hence farer away from the sea surface 212 and nearer to the sea ground 213 as compared to the floating foundation 120 shown in FIG. 1. The floating foundation 220 is moved along the heave 101 (shown in FIG. 1). However, it may be understood that the floating foundation 220 may also additionally or alternatively be moved in surge 103 and/or sway 102. Therefore, a collision with the first formation of ice 271 and the second formation of ice 272 is inhibited.

[0088] Further, an ice inhibiting device 292, particularly an underwater propeller 292 is mounted to the floating foundation 220. The underwater propeller 292 may support a movement of the floating foundation 220 and hence of the floating wind turbine 200.

[0089] A further ice inhibiting device 293, particularly an autonomous underwater vehicle 293, is shown on the sea ground 213.

[0090] As may be seen in FIG. 2, the control system is formed as a multi-piece control system comprising the vision-based detection device 281, the device 282 configured for analysing a change in a dynamics of the floating wind turbine 200, the first mooring line actuator 291, the second mooring line actuator 292, the underwater propeller 292 and the autonomous underwater vehicle 293.

[0091] 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.

[0092] 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.