Coil configurations for inductive power transfer

• US 9,054,542 B2
• Filed: 06/09/2011
• Issued: 06/09/2015
• Est. Priority Date: 06/10/2010
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Baarman, David W.
• Primary Examiner(s): AMAYA, CARLOS DAVID
• Application Number:
  US13/156,390
• Publication Number:
  US 20110304216A1
• Time in Patent Office: 1,461 Days
• Field of Search: 307/104
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection

Abstract

An inductive power supply system in which the receiving unit includes a secondary coil and a plurality of resonating circuits with different characteristics. Each of the resonating circuits may include a resonating coil and a resonating capacitor. The resonating coils may be inductively coupled to the secondary coil so that energy may be transferred from one or more of the resonating coils to said receiving unit. The plurality of resonating circuits are configured to provide improved power transfer efficiency or performance at different distances between the primary coil and secondary coil. The present invention may also provide a method for tuning the wireless power system including the general steps of measuring an operating characteristic in the primary unit, measuring an operating characteristic in the receiver unit and tuning one or more of the components in the primary unit and the secondary unit based on a comparison of the two measurements.

Claims

1. A inductive power supply system comprising:

a primary unit for transmitting wireless power, said primary unit including;

a primary circuit having a primary for producing a first field; and

a receiving unit separable from said primary unit and for receiving said wireless power from said primary unit, said receiving unit including;

two or more secondary resonating circuits configured to receive said wireless power over a range of distances from said primary unit, wherein each of said two or more secondary resonating circuits is configured to receive said wireless power at different distances between said primary unit and said receiving unit;

wherein one of said two or more secondary resonating circuits is configured for efficient energy transfer over a first portion of said range of distances and another of said two or more secondary resonating circuits is configured for efficient energy transfer over a second portion of said range of distances, wherein said first portion of said range of distances is different from said second portion of said range of distances;

a secondary circuit for receiving said wireless power by inductively coupling with at least one of (i) said primary circuit and (ii) one of said two or more secondary resonating circuits; and

wherein said two or more secondary resonating circuits are configured to inductively couple with said secondary circuit to transfer received wireless power to said secondary circuit.

2. The inductive power supply system of claim 1 wherein said two or more secondary resonating circuits are configured to account for an affect on mutual inductance with said primary unit at different locations of said receiving unit with respect to said primary unit.

3. The inductive power supply system of claim 1 wherein said secondary circuit is configured for efficient energy transfer at a first distance and one of said two or more secondary resonating circuits is configured for efficient energy transfer at a second distance, wherein said first distance is different from said second distance.

4. The inductive power supply system of claim 1 wherein each of said two or more secondary resonating circuits includes a resonating coil and a resonating capacitor, and wherein each of said two or more secondary resonating circuits is tuned to a different resonant frequency.

5. The inductive power supply system of claim 1 wherein at least one of said two or more secondary resonating circuits are configured to be selectively activated via a switch for transferring wireless power wirelessly between said primary unit and said receiving unit.

6. The inductive power supply system of claim 1 wherein said primary circuit includes a primary capacitor, wherein said primary circuit is configured to have a resonant frequency.

7. The inductive power supply system of claim 1 wherein at least one of said primary circuit and said two or more resonating circuits includes a variable capacitor capable of changing capacitance in order to achieve a desired tuning and a desired affect on mutual inductance between said primary unit and said receiving unit.

8. The inductive power supply system of claim 1 wherein said primary unit includes a primary resonating circuit having a primary resonator configured to receive power via said first field and configured to produce a second field;

wherein said secondary circuit for receiving said wireless power by inductively coupling with said primary resonator.

9. The inductive power supply system of claim 1 wherein said primary resonating circuit is selectively activated via a switch for transferring wireless power between said primary unit and said receiving unit such that (a) said primary resonating circuit transfers wireless power to said receiving unit via said second field in response to said primary resonating circuit being activated and (b) said primary transfers wireless power to said receiving unit via said first field in response to said primary resonating circuit being deactivated.

10. The inductive power supply system of claim 9 wherein said receiving unit is included in a remote device.

11. A remote device for receiving power from an inductive power supply, said remote device comprising:

two or more resonating circuits configured to inductively couple with said inductive power supply, each of said two or more resonating circuits receives power efficiently over a range of different distances between said remote device and said inductive power supply; and

a secondary circuit configured for inductively coupling with at least one of said two or more resonating circuits and said inductive power supply for receiving power wirelessly, said secondary circuit receives power efficiently at a distance less than said range of different distances at which each of said two or more resonating circuits receive power efficiently;

wherein one of said two or more secondary resonating circuits is configured for efficient energy transfer at a first distance portion of said range and another of said two or more secondary resonating circuits configured for efficient energy transfer at a second distance portion of said range, wherein said first distance portion is different from said second distance portion; and

wherein said two or more secondary resonating circuits are configured to inductively coupled with said secondary circuit to transfer received wireless power to said secondary circuit.

12. The remote device of claim 11 wherein overlap exists between said first distance portion of said range and said second distance portion of said range.

13. The remote device of claim 11 wherein said two or more resonating circuits and said secondary circuit are configured to account for an affect on mutual inductance at different locations between said remote device and said inductive power supply.

14. The remote device of claim 11 wherein at least one of said two or more resonating circuits are configured to be selectively activated via an associated switch for transferring power wirelessly between said inductive power supply and said remote device such that said at least one of said two or more resonating circuits receives power wirelessly from said inductive power supply in response to being activated.

15. The remote device of claim 11 wherein at least one of said two or more resonating circuits includes a variable capacitor capable of changing capacitance in order to achieve a desired tuning and a desired affect on mutual inductance between said remote device and said inductive power supply.

16. The remote device of claim 11

including an additional secondary resonating circuit configured for efficient energy transfer over a third distance portion of said range, and wherein overlap exists between at least two of said first distance portion of said range, said second distance portion of said range, and said third distance portion of said range.