Wireless energy transfer to moving devices

• US 8,384,247 B2
• Filed: 01/13/2010
• Issued: 02/26/2013
• Est. Priority Date: 01/13/2010
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Yerazunis, William S., Iyer, Vishwanath, Huang, Da, Duan, Chunjie, Teo, Koon Hoo
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): VU, TOAN T
• Application Number:
  US12/686,497
• Publication Number:
  US 20110169336A1
• Time in Patent Office: 1,140 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: B66B 7/00 Other common features of elevators
• CPC Class Codes: H02J 5/005 with inductive power transfer for charging H02J7/025
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

A system exchanges energy wirelessly and includes a source configured to generate evanescent waves, in response to receiving the energy, on at least part of a surface of the source. The system also includes a sink configured to receive the energy wirelessly from the source via a coupling of the at least part of the evanescent waves and a load configured to receive the energy from the sink. The load and the sink are configured to move along the surface of the source such that the at least a part of the evanescent waves are coupled between the source and the sink within an energy transfer area.

Claims

1. A system configured to transfer energy wirelessly, comprising:

a source configured to generate evanescent waves, in response to receiving the energy, on at least part of a surface of the source;

a sink configured to receive the energy wirelessly from the source via a coupling of the at least part of the evanescent waves; and

a load configured to receive the energy from the sink, wherein the load and the sink are configured to move along the surface of the source such that the at least a part of the evanescent waves are coupled between the source and the sink within an energy transfer area.

2. The system of claim 1, wherein the source is a waveguide.

3. The system of claim 1, further comprising:

a driver configured to supply the energy to the source.

4. The system of claim 1, further comprising:

a negative index material (NIM) arranged within the energy transfer area such that the coupling is enhanced.

5. The system of claim 1, wherein the source and the sink are resonant structures.

6. The system of claim 2, wherein the NIM is arranged based on the predetermined location of the sink.

7. The system of claim 1, wherein the load is an elevator car.

8. The system of claim 1, wherein the load is a train.

9. The system of claim 1, wherein the sink is arranged based on an energy distribution pattern selected from a group of patterns consistent of an even butterfly pattern, an odd butterfly pattern, even crossing pattern, and an odd crossing pattern.

10. The system of claim 1, wherein the NIM has a negative permittivity property and a negative permeability property.

11. The system of claim 3, further comprising:

a power meter configured to supply at least part of the energy to the driver.

12. The system of claim 2, wherein the waveguide includes slots configured to generate the evanescent waves.

13. The system of claim 2, wherein the waveguide is an optical waveguide.

14. The system of claim 2, wherein the sink includes a loop, wherein the loop is rotated such that an axis of the loop is perpendicular to the waveguide.

15. A method for transferring energy wirelessly via a coupling of near-fields, comprising steps of:

providing a source configured to transfer an energy wirelessly to a sink via the coupling of near-fields of the source and the sink, wherein the source and the sink are non-radiative structures configured to generate EM near-fields in response to receiving the energy; and

moving the sink along a surface of the source such that the near-field of the source and the near-field of the sink are coupled within an energy transfer area.

16. The method of claim 15, further comprising:

implementing the source as a waveguide such that the near-field is generated on at least part of the surface of the waveguide.

17. The method of claim 15, further comprising:

supplying the energy from a driver to the source; and

supplying the energy from the sink to a load.

18. The method of claim 17, wherein the load is an elevator or a train.

19. The method of claim 15, further comprising:

supplying the energy, unused during the transferring of the energy from the source to the sink, to the driver.

20. The method of claim 15, further comprising:

determining an amount the energy unused during the transferring of the energy from the source to the sink;

transmitting a feedback control signal indicating the amount to a driver; and

controlling the energy of the driver such that to minimize the energy unused during the transferring.

21. The method of claim 17, further comprising:

increasing the coupling using negative index material (NIM).