Wave power assembly with an electromagnetic dampning means

• US 7,355,293 B2
• Filed: 04/13/2004
• Issued: 04/08/2008
• Est. Priority Date: 04/14/2003
• Status: Expired due to Fees

• Current Assignee: Seabased AB
• Original Assignee: Seabased AB
• Inventors: Leijon, Mats, Bernhoff, Hans
• Primary Examiner(s): GONZALEZ, JULIO C
• Application Number:
  US10/552,329
• Publication Number:
  US 20070040384A1
• Time in Patent Office: 1,456 Days
• Field of Search: 290/53, 290/42, 415/7, 604/98, 417/332
• US Class Current: 290/42
• CPC Class Codes: F03B 13/14 using wave energy
• CPC Class Codes: F05B 2220/707 of the linear type
• CPC Class Codes: Y02E 10/30 Energy from the sea, e.g. using wave energy or salinity gradient

Abstract

A wave power assembly comprising a hull and a linear electric generator. The rotor is connected to the hull and the stator is arranged to be anchored at a sea/lake bottom. The generator is provided with an electromagnetic damping means in order to keep the pulsations of the axial force exerted by the stator on the rotor at a relatively low level, which damping means comprises geometric arrangement adapted herefor of at least some one of the stator winding, the stator slots and the rotor magnets. The invention also relates to a wave power plant built up from wave power assemblies according to the invention. Furthermore, the invention relates to a use of the wave power assembly and a method for generation of electric energy.

Claims

1. A wave power assembly comprising;

a hull;

a linear electric generator having a rotor and a stator, the rotor being configured with magnets and being connected to said hull, said stator having slots and windings and being adapted to be anchored to a sea/lake bottom; and

electromagnetic damping means, said damping means being configured to maintain at a relatively low level the pulsations of the axial force exerted by said stator on said rotor, said damping means comprising a geometric configuration of at least one of said stator windings in said stator slots, and said rotor magnets.

2. The wave power assembly according to claim 1, wherein said stator comprises multiphase winding, and said electromagnetic damping means comprises said stator winding configured as a fractional slot winding.

3. The wave power assembly according to claim 2, wherein said stator comprises a 3-phase winding.

4. The wave power assembly according to claim 2, wherein said fractional slot winding has a winding factor that is greater than one.

5. The wave power assembly according to claim 3, wherein said fractional slot winding has a winding factor that is greater than one.

6. The wave power assembly according to claim 2, wherein said fractional slot winding has a winding factor that is less than one.

7. The wave power assembly according to claim 3, wherein said fractional slot winding has a winding factor that is less than one.

8. The wave power assembly according to claim 1, wherein said stator comprises a plurality of stator packs evenly distributed around said rotor, each said stator pack having a winding that comprises a fractional slot winding.

9. The wave power assembly according to claim 1, wherein said magnets are configured as a plurality of magnetic poles, said electromagnetic damping means is so configured that at least some of said poles of said rotor, or some of said winding slots of said stator, or both, are oriented obliquely in relation to a plane perpendicular to the direction of motion of said rotor.

10. The wave power assembly according to claim 2, wherein said magnets are configured as a plurality of magnetic poles, said electromagnetic damping means is so configured that at least some of said poles of said rotor, or some of said winding slots of said stator, or both, are oriented obliquely in relation to a plane perpendicular to the direction of motion of said rotor.

11. The wave power assembly according to claim 8, wherein said magnets are configured as a plurality of magnetic poles, said electromagnetic damping means is so configured that at least some of said poles of said rotor, or some of said winding slots of said stator, or both, are oriented obliquely in relation to a plane perpendicular to the direction of motion of said rotor.

12. The wave power assembly according to claim 9, wherein said magnetic poles comprise magnets of an elongate shape having a longitudinal axis that forms an angle to a plane perpendicular to the direction of motion of said rotor.

13. The wave power assembly according to claim 10, wherein said magnetic poles comprise magnets of an elongate shape having a longitudinal axis that forms an angle to a plane perpendicular to the direction of motion of said rotor.

14. The wave power assembly according to claim 11, wherein said magnetic poles comprise magnets of an elongate shape having a longitudinal axis that forms an angle to a plane perpendicular to the direction of motion of said rotor.

15. The wave power assembly according to claim 9, wherein each of said magnetic poles comprises a group of a plurality of magnets, said magnets being axially displaced in relation to each other.

16. The wave power assembly according to claim 12, wherein each of said magnetic poles comprises a group of a plurality of magnets, said magnets being axially displaced in relation to each other.

17. The wave power assembly according to claim 9, wherein each of said winding slots forms an angle to a plane perpendicular to the direction of motion of said rotor.

18. The wave power assembly according to claim 12, wherein each of said winding slots forms an angle to a plane perpendicular to the direction of motion of said rotor.

19. The wave power assembly according to claim 15, wherein each of said winding slots forms an angle to a plane perpendicular to the direction of motion of said rotor.

20. The wave power assembly according to claim 1, wherein said rotor comprises a permanent magnetic.

21. A wave power plant comprising a plurality of wave power assemblies according to claim 1.

22. The use of a wave power assembly according to claim 1 in order to generate electric energy.

23. A method in order to generate electric energy by means of at least one wave power assembly according to claim 1.