Airborne wind turbine electricity generating system

• US 7,582,981 B1
• Filed: 06/23/2008
• Issued: 09/01/2009
• Est. Priority Date: 05/19/2008
• Status: Expired due to Fees

• Current Assignee: Moshe Meller
• Original Assignee: Moshe Meller
• Inventors: Meller, Moshe
• Primary Examiner(s): Ponomarenko; Nicholas
• Application Number:
  US12/144,222
• Time in Patent Office: 435 Days
• Field of Search: 290/43, 290/44, 290/54, 290/55, 415/4.3, 415/7
• US Class Current: 290/44
• CPC Class Codes: F03D 1/025 coaxially arranged
• CPC Class Codes: F03D 13/20 Arrangements for mounting or supporting wind motors; Masts or towers for wind motors
• CPC Class Codes: F03D 15/10 using gearing not limited to rotary motion, e.g. with oscillating or reciprocating members
• CPC Class Codes: F03D 80/70 Bearing or lubricating arrangements
• CPC Class Codes: F03D 9/11 storing electrical energy
• CPC Class Codes: F03D 9/25 the apparatus being an electrical generator F03D9/22 takes precedence
• CPC Class Codes: F05B 2240/921 kept aloft due to aerodynamic effects
• CPC Class Codes: F05B 2240/922 kept aloft due to buoyancy effects
• CPC Class Codes: F05B 2240/923 which is a vehicle
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/728 Onshore wind turbines
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

An airborne system for producing electricity from wind energy includes a shaft, at least two turbines rotatably mounted to the shaft and arranged to rotate independent of one another and in opposite directions when subjected to the same wind, and generators which convert rotation of the turbines into electricity. The magnitude of electricity generation by the generators is related to the magnitude of torque induced by the generators on the shaft, and the electricity generation by the generators may be controlled such that torques induced on the shaft by the generators is controlled such that a sum of torques induced on the shaft is substantially zero. A lifting structure generates a lifting force to lift the turbines to a desires altitude, and an anchoring system anchors the turbines relative to the ground. Generated electricity is conducted to users, to electricity storage, or to processing components.

Claims

1. An airborne system for producing electricity from wind energy, comprising:

a turbine section comprising;

a shaft;

at least first and second turbines rotatably mounted to said shaft and arranged to rotate independently of one another and in opposite directions about said shaft when subjected to a same wind; and

at least first and second generators respectively coupled to said at least first and second turbines and arranged to convert rotation of said first and second turbines into electricity, said generators being mounted so as to be fixed relative to said shaft, the magnitude of electricity generation by said generators being related to a torque induced on said shaft by said generators responsive to rotation of said turbines relative to said shaft;

a lifting system coupled to said turbine section for generating a lifting force to cause said turbine section to be airborne at a desired altitude;

an anchoring section arranged to anchor said turbine section relative to the ground; and

said turbines having aerodynamic characteristics which provide in combination with the effect of the electricity generation by said generators a situation where a sum of torques acting on said shaft is substantially zero so that said turbine section is angularly stable when airborne;

wherein electricity generated by said generators is conducted to an energy utilization device for usage or to electricity storage.

2. The system of claim 1, further comprising an angular stability controller coupled to at least one of said generators for controlling the electricity generation by said at least one generator and thus the magnitude of the torque that each of said at least one generator induces on said shaft, said angular stability controller being adapted to control said at least one generator in order to achieve substantially zero resultant torque induced on said shaft by said first and second turbines through said generators and thereby enable continuous angular stability of the system.

3. The system of claim 2, comprising an angular stability controller coupled to each of said at least first and second generators.

4. The system of claim 2, further comprising at least one fin fixed relative to said shaft, and a controllable flap attached to each of said at least one fin, said controllable flap having a variable angular position relative to said fin to which it is attached, and said angular stability controller being arranged to control said variable angular position of said flap of each of said at least one fin to aid in maintaining angular stability of the system.

5. The system of claim 3, wherein said angular stability controllers are arranged to utilize an electronic artificial horizon as a reference in order to achieve continuous angular stability of the system relative to the horizon.

6. The system of claim 3, wherein said angular stability controllers are arranged to integrate electricity output from said generators to a common electricity output conduit.

7. The system of claim 3, wherein said first and second turbines comprise blades which have a controllable variable angle of attack, said angular stability controller being arranged to control the angle of attack of said blades of said first and second turbines to aid in maintaining the angular stability of the system.

8. The system of claim 1, wherein each of said at least first and second turbines comprise a plurality of blades.

9. The system of claim 1, wherein each of said first and second turbines comprises two blades.

10. The system of claim 1, further comprising a support structure for supporting said at least first and second generators in a fixed position relative to said shaft.

11. The system of claim 1, wherein each of said generators includes a rotatable shaft whose rotation causes generation of electricity, and further comprising a transmission system interposed between said turbines and said generators for transmitting rotation of said turbines into rotation of said shafts of said generators and thus generation of electricity by said generators.

12. The system of claim 1, further comprising an electrical conductor system for conducting electricity from said generators to an electricity storage, usage or processing component.

13. The system of claim 1, wherein said anchoring section comprises a tether connected to said lifting structure or to said shaft, and a winch for adjusting a length of said tether relative to the ground.

14. The system of claim 1, wherein said lifting system comprises a first inflatable body arranged on one side of said turbine section and a second inflatable body arranged on an opposite side of said turbine section, said first and second inflatable bodies being receivable of a lighter-than-air gas.

15. The system of claim 14, wherein the lighter-than-air gas is helium.

16. The system of claim 1, wherein said lifting system comprises a single inflatable body coupled to said turbine section and receivable of a lighter-than-air gas, and said anchoring section comprises a tether connected to said turbine section.

17. The system of claim 1, wherein said lifting system comprises at least one independent lift-generating body spaced apart from said turbine section, and said at least one lift-generating body being connected to said turbine section to transfer a lifting force generated by said at least one lift-generating body to said turbine section.

18. The system of claim 17, further comprising:

a connecting device connecting said at least one lift-generating body to said shaft;

an angular stability controller coupled to said generators for controlling the electricity generation by said generators and thus the magnitude of the torque that each of said generators induces on said shaft, said angular stability controller being adapted to control said generators in order to achieve substantially zero resultant torque induced on said shaft by said first and second turbines through said generators and thereby enable continuous angular stability of the system; and

at least one fin coupled to said shaft and a controllable flap attached to each of said at least one fin, said controllable flap having a variable angular position relative to said fin to which it is attached, and said angular stability controller being arranged to control said flap of each of said at least one fin to aid in maintaining angular stability of the system.

19. The system of claim 17, wherein said at least one lift-generating body is receivable of a lighter-than-air gas.

20. The system of claim 17, wherein said at least one lift-generating body is non-inflatable and has aerodynamic characteristics which enable it to assume a position in which it generates and transfers sufficient lifting force to said turbine section when exposed to wind to enable said turbine section to remain airborne.

21. The system of claim 17, wherein said at least one lift-generating body comprises an unmanned helicopter driven by power drawn from a power source or from electricity generated by said turbine section.

22. The system of claim 1, wherein said first and second turbines each comprise rotatable blades, and wherein the blades of a turbine upwind of another turbine have a smaller diameter than the blades of the turbine which is downwind of the upwind turbine.

23. An airborne system for producing electricity from wind energy, comprising:

a turbine section comprising;

a shaft;

at least first and second turbines rotatably mounted to said shaft and arranged to rotate independently of one another and in opposite directions about said shaft when subjected to a same wind; and

at least first and second generators respectively coupled to said at least first and second turbines and arranged to convert rotation of said first and second turbines into electricity, said generators being mounted so as to be fixed relative to said shaft, the magnitude of electricity generation by said generators being related to a torque induced on said shaft by said generators responsive to rotation of said turbines relative to said shaft;

a lifting system coupled to said turbine section for generating a lifting force to cause said turbine section to be airborne at a desired altitude;

an anchoring section arranged to anchor said turbine section relative to the ground; and

said turbines having aerodynamic characteristics which provide in combination with the effect of the electricity generation by said generators a situation where a sum of torques acting on said shaft is substantially zero so that said turbine section is angularly stable when airborne;

wherein electricity generated by said generators is conducted to an energy utilization device for usage or to electricity storage.

24. An airborne system for producing electricity from wind energy, comprising:

a turbine section comprising;

a shaft;

at least first and second turbines rotatably mounted to said shaft and arranged to rotate independently of one another and in opposite directions about said shaft when subjected to a same wind; and

a generator coupled to said at least first and second turbines and arranged to convert rotation of said first and second turbines into electricity, said generator being mounted so as to be fixed relative to said shaft, the magnitude of electricity generation by said generator being related to a torque induced on said shaft by said generator responsive to rotation of said turbines relative to said shaft;

a lifting system coupled to said turbine section for generating a lifting force to cause said turbine section to be airborne at a desired altitude;

an anchoring section arranged to anchor said turbine section relative to the ground; and

said turbines having aerodynamic characteristics which provide in combination with the effect of the electricity generation by said generator a situation where a sum of torques acting on said shaft is substantially zero so that said turbine section is angularly stable when airborne;

wherein electricity generated by said generator is conducted to an energy utilization device for usage or to electricity storage.

25. The system of claim 24, further comprising a transmission structure for coupling both of said first and second turbines to said generator.

26. The system of claim 25, further comprising at least one fin fixed relative to said shaft and controllable flap attached to each of said at least one fin, said controllable flap having a variable angular position relative to said fin to which it is attached, and an angular stability controller arranged to control the angle of attack of blades of said first and second turbines and said variable angular position of said flap of each of said at least one fin to aid in maintaining angular stability of the system, and wherein said first and second turbines have predetermined aerodynamic characteristics that aid in maintaining angular stability of the system.