ENERGY HARVESTING SYSTEM USING SEVERAL ENERGY SOURCES

• US 20130342032A1
• Filed: 08/29/2013
• Published: 12/26/2013
• Est. Priority Date: 10/21/2011
• Status: Active Grant

• Current Assignee: Université de Liège
• Original Assignee: Université de Liège
• Inventors: LAURENT, Philippe
• Granted Patent: US 9,653,980 B2
• Time in Patent Office: Days
• US Class Current: 310/17
• CPC Class Codes: A61M 2205/8293 Solar
• CPC Class Codes: H02K 35/00 Generators with reciprocating, oscillating or vibrating coil system, magnet, armature or other part of the magnetic circuit arrangements for handling mechanical energy structurally associated with generators H02K7/00, e.g. H02K7/06
• CPC Class Codes: H02K 35/02 with moving magnets and stationary coil systems
• CPC Class Codes: H02K 35/04 with moving coil systems and stationary magnets
• CPC Class Codes: H02K 35/06 with moving flux distributors, and both coil systems and magnets stationary
• CPC Class Codes: H02K 7/00 Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
• CPC Class Codes: H02N 11/002 Generators

Abstract

An object of the invention is to provide a cheap, efficient and polyvalent energy harvesting system able to exploit several energy sources.

The invention proposes an energy harvesting system (100) comprising a frame, at least one permanent magnet (101) having a North/South direction, and at least one winding (107, 108) wound according to a winding direction around a core (103a-103b) comprising a high magnetic permeability material, at least said at least one permanent magnet being mounted on the frame to be able to oscillate relatively to the winding, characterized in that the system comprises a magnetic flux divider arranged between said at least one permanent magnet and said at least one winding in order to concentrate the magnetic flux at discrete positions of maximum magnetic flux then forming equilibrium positions where the winding faces one of the said discrete positions of maximum magnetic flux.

Claims

1. An energy harvesting system comprising a frame, at least one permanent magnet having a North/South direction, and at least one winding wound according to a winding direction around a core comprising a high magnetic permeability material, one permanent magnet being mounted on the frame to be able to oscillate relatively to the winding, wherein the system comprises a magnetic flux divider arranged between said at least one permanent magnet and said at least one winding in order to concentrate the magnetic flux at discrete positions of maximum magnetic flux then forming equilibrium positions where the winding faces one of the said discrete positions of maximum magnetic flux.

2. The energy harvesting system according to claim 1, wherein the magnetic flux divider comprises a stack of a plurality of permanent magnets separated from each other by a fixed spacing, the polarizations North/South of two consecutive magnet being alternated.

3. The energy harvesting system according to claim 1, wherein the magnetic flux divider comprises at least two magnetic guides made of a material having high magnetic permeability, separated by a magnetic and electric isolator made of non conductive and non magnetic material, the magnetic guides being arranged between said at least one permanent magnet and said at least one winding.

4. The energy harvesting system according to claim 1, wherein it comprises:

a cantilever beam with a clamped extremity to the frame and a free extremity, the beam having a beam core made of a material allowing an oscillating movement of the free extremity;

a high frequency mass mounted at the free extremity of the cantilever beam, the high frequency mass being formed by the winding wound around a mass core comprising a high magnetic permeability material,

at least two permanent magnets fixed and arranged to a magnet support made of high magnetic permeability material, such that

the North/South direction is perpendicular to the magnet support,

the permanent magnets are separated from each other by a fixed spacing,

that magnet polarizations are alternated,

and in that the winding faces the at least two permanent magnets such that the winding direction is parallel to the North/South direction and such that the winding is separated from the permanent magnets by a fixed spacing.

5. The energy harvesting system according to claim 4, wherein the magnet support is elastically mounted relatively to the frame.

6. An The energy harvesting system according to claim 4, wherein the beam core is made of a material chosen from a spring material, a shape-memory alloy, and a bimetallic assembly.

7. The energy harvesting system according to claim 4, wherein the beam further comprises an external layer made of piezoelectric material.

8. The energy harvesting system according to claim 1, wherein it comprises, in a rest position:

A permanent magnet elastically mounted on the frame, the permanent magnet further comprising, at each pole, spreaders made of a material having high magnetic permeability,

A magnetic circuit comprising magnetic plates alternatively stacked in a stack direction with plates made of non conductive and non magnetic material to electrically and magnetically insulate the magnetic plates from each other, the North/South direction of the magnet being perpendicular to the stack direction, the magnetic circuit facing both the North and South poles of the permanent magnet,

At least one winding wound around at least one part (103a) of the magnetic circuit located in a same side as the North Pole of the permanent magnet in a rest position,

At least one winding wound around at least one part of the magnetic circuit located in a same side as the South Pole of the permanent magnet in the rest position.

9. The energy harvesting system according to claim 8, wherein the frame is a housing comprising a container and a lid elastically mounted on each other via a spring.

10. The energy harvesting system according to claim 8, wherein the magnetic plates have a ring shape part, further comprising two cantilever arms extending along opposite internal directions of the ring shape part, such that, when positioned in the energy harvesting system, the cantilever arms are facing the poles of the permanent magnet, the ring part surrounding the cantilever arms and the magnet.

11. The energy harvesting system according to claim 10, wherein the ring shape is chosen from a rectangular ring shape, a square ring shape, an oval ring shape, and a circular ring shape.

12. The energy harvesting system according to claim 10, wherein the cantilever arms are symmetrical relative to a center of the ring shape.

13. The energy harvesting system according to claim 12, wherein consecutive magnetic plates are arranged such that their respective arms are in same positions.

14. The energy harvesting system according to claim 12, wherein consecutive magnetic plates are arranged such that their respective arms are in opposite positions.

15. The energy harvesting system according to claim 8, wherein the permanent magnet is elastically mounted on the frame by two opposite springs.

16. The energy harvesting system according to claim 15, wherein at least one of the springs is flat spiral spring comprising at least one spiral blade wider than thicker.

17. The energy harvesting system according to claim 16, wherein one of the springs is a thermoactuor able to move the permanent magnet when the thermoactuor is subjected to a temperature change.

18. The energy harvesting system according to claim 17, wherein the thermoactuator is chosen from a bimetallic element, a shape memory alloy, and an element comprising a phase change material.

19. A The energy harvesting system according to claim 8, wherein the permanent magnet and the spreaders are embedded in a holder fixed to the springs.

20. The energy harvesting system according to claim 8, wherein the magnetic circuit is fixed to the frame by the support of the magnetic circuit.

21. The energy harvesting system according to claim 9, wherein the support of the magnetic circuit is fixed on the container and the spring comprising the thermoactuator is fixed to the lid.

22. At The energy harvesting system according to claim 17, wherein the magnetic circuit support further comprises thermally conductive fingers arranged relative to the spring comprising the thermoactuator in order to contact and cool the thermoactuator when it is deformed in response to a given temperature change.