Processing

Please wait...

Settings

Settings

Goto Application

1. WO2020139444 - USE OF WAVE ENERGY BY ENERGY KITE AND FLOATING PLATFORM

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[ EN ]

CLAIMS

What is claimed is:

1. A method comprising:

determining, by a control system for an airborne wind turbine, wave data

corresponding to a floating ground station of the airborne wind turbine, wherein an aerial vehicle is coupled to the floating ground station via a tether;

determining, by the control system, based at least in part on the wave data, an oscillation profile of the floating ground station, wherein the oscillation profile indicates an oscillation period and phase for oscillation of the floating ground station; and

operating the aerial vehicle to fly in a closed path with: (a) a looping period that substantially matches the period of wave-influenced oscillation of the floating ground station, and (b) a looping phase that substantially aligns with the oscillation phase of the floating ground station such that movement of the aerial vehicle on a downstroke portion of the closed path corresponds to forward displacement of the floating ground station, and movement of the aerial vehicle on an upstroke portion the closed path corresponds to reverse displacement of the floating ground station.

2. The method of claim 1, wherein operating the aerial vehicle to fly in the closed path comprises:

aligning the looping phase of the aerial vehicle with the oscillation phase such that forward displacement of the floating ground station tends to decrease a ground- station tensioning force applied to the tether during downstroke movement of the aerial vehicle, and such that backward displacement of the floating ground station tends to increase the ground-station tensioning force applied to the tether during upstroke movement of the aerial vehicle.

3. The method of claim 1, wherein the floating airborne wind turbine ground station comprises a spar buoy, wherein the spar buoy is coupled to a mooring via a mooring line at a coupling point, and wherein the oscillation of the floating airborne wind turbine ground station corresponds to rotation of the spar buoy about the coupling point.

4. The method of claim 1, wherein the floating airborne wind turbine ground station comprises a spar buoy, wherein the spar buoy is coupled to a mooring via a mooring line at a coupling point, and wherein the oscillation of the floating airborne wind turbine ground station corresponds to rotation of the spar buoy, the mooring line, or both, about the mooring.

5. The method of claim 1, wherein determining the oscillation profile of the floating ground station comprises: using the wave data as a basis for determining wave force experienced by the floating ground station; and

based at least in part on the determined wave force over time, determining the period and phase for oscillation of the floating ground station.

6. The method of claim 1, further comprising:

determining wind data corresponding to the floating ground station; and

using the wind data as a further basis for determining the oscillation profile of the floating ground station.

7. The method of claim 1, further comprising:

initially determining, by the control system whether or not waves are present at the floating ground station’s location;

when waves are not present, operating the aerial vehicle to fly in a closed path with a looping period and phase that match a period and phase of natural oscillation for the ground station; and

when waves are present, implementing the steps of determining the wave data, determining the oscillation profile based on the wave data, and operating the aerial vehicle to fly in the closed path with: (a) the looping period that substantially matches the period of wave-influenced oscillation of the floating ground station, and (b) the looping phase that substantially aligns with the oscillation phase of the floating ground station such that movement of the aerial vehicle on the downstroke portion of the closed path corresponds to forward displacement of the floating ground station, and movement of the aerial vehicle on the upstroke portion the closed path corresponds to reverse displacement of the floating ground station.

8. The method of claim 7, wherein operating the aerial vehicle to fly in a closed path with a looping period and phase that match a period and phase of natural oscillation for the ground station comprises:

determining a period of natural oscillation of the floating ground station in the absence of waves, wherein each natural-oscillation period comprises a natural forward displacement and a natural backward displacement of the floating ground station with respect to the aerial vehicle;

determining a phase of the natural oscillation of the floating ground station; and operating the aerial vehicle to fly in a second closed path with: (a) a looping period that matches the natural-oscillation period of the floating ground station, and (b) a looping phase that aligns with the natural-oscillation phase of the floating ground station such that movement of the aerial vehicle on a downstroke portion the second closed path corresponds to natural forward displacement of the floating ground station, and movement of the aerial vehicle on an upstroke portion the circular path corresponds to natural backward displacement of the floating ground station.

9. The method of claim 7, wherein the natural oscillation of the floating airborne wind turbine ground station corresponds to current, wind, or both.

10. An airborne wind turbine (AWT) system comprising:

an aerial vehicle;

a floating ground station; and

a control system configured to:

determine wave data corresponding to a floating ground station of an airborne wind turbine, wherein an aerial vehicle is coupled to the floating ground station via a tether;

determine, based at least in part on the wave data, an oscillation profile of the floating ground station, wherein the oscillation profile indicates an oscillation period and phase for oscillation of the floating ground station; and operate the aerial vehicle to fly in a closed path with: (i) a looping period that substantially matches the period of wave-influenced oscillation of the floating ground station, and (ii) a looping phase that substantially aligns with the oscillation phase of the floating ground station such that movement of the aerial vehicle on a downstroke portion of the closed path corresponds to forward displacement of the floating ground station, and movement of the aerial vehicle on an upstroke portion the closed path corresponds to reverse displacement of the floating ground station.

11. The method of claim 10, wherein the closed path is substantially circular.

12. The system of claim 10, wherein operation of the aerial vehicle to fly in a closed path comprises:

alignment of the looping phase of the aerial vehicle with the oscillation phase such that forward displacement of the floating ground station decreases a ground-station tensioning force applied to the tether during downstroke movement of the aerial vehicle on the closed path, and such that backward displacement of the floating ground station increases the ground-station tensioning force applied to the tether during upstroke movement of the aerial vehicle on the closed path.

13. The system of claim 10, wherein the floating airborne wind turbine ground station comprises a spar buoy, wherein the spar buoy is coupled to a mooring via a mooring line at a coupling point, and wherein the oscillation of the floating airborne wind turbine ground station corresponds to rotation of the spar buoy about the coupling point.

14. The system of claim 11, wherein the oscillation of the floating airborne wind turbine ground station further corresponds to rotation of the spar buoy, the mooring line, or both, about the mooring.

15. The system of claim 10, further comprising one or more sensors operable to generate the wave data or data from which the wave data is derived.

16. The system of claim 15, wherein the floating ground station comprises one or more sensors operable to generate the wave data or data from which the wave data is derived.

17. The system of claim 15, wherein the one or more sensors comprise one or more of the following types of sensors: an inertial measurement unit, a motion sensor, a mechanical fluid sensor, a float sensor, an altimeter, a radar system, an acoustic wave sensor, or a pressure-based wave sensor.

18. The system of claim 10, further comprising a floating data collection device, wherein the floating data collection device comprises:

one or more sensors operable to generate sensor data comprising the wave data or data from which the wave data is derived; and

a communication interface for transmission of the sensor data.

19. The system of claim 18, wherein the floating data collection device is located near to the AWT system and is configured to generate wave data for the AWT system.

20. The system of claim 18, wherein the floating data collection device is further configured to generate wave data for a plurality of nearby AWT systems.