Wireless power transfer

Patent metadata

Field	Value
Publication number	US-9800076-B2
Application number	US-201414502191-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Feb 14, 2014
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A method includes determining, by a base station including a number of transmitting coils, a first number of mutual magnetic parameters, each mutual magnetic parameter being associated with one of the transmitting coils and a receiving coil of at least one receiving coil associated with at least one electronic device remotely located from and to be remotely charged by the base station, determining a plurality of control signals based on the first number of mutual magnetic parameters, each control signal being associated with a corresponding one of the transmitting coils, providing each control signal to a driving circuit coupled to the control signal's corresponding transmitting coil, and using each control signal to cause the driving circuit coupled to the control signal's corresponding transmitting coil to cause a current with a magnitude and phase determined from the control signal to flow in the corresponding transmitting coil.

First claim

What is claimed is:

1. A method, comprising:
determining, by a base station comprising a plurality of transmitting coils, a first plurality of mutual magnetic parameters, each mutual magnetic parameter of the first plurality of mutual magnetic parameters being associated with a transmitting coil of the plurality of transmitting coils and a receiving coil of at least one receiving coil associated with at least one electronic device remotely located from and to be remotely charged by the base station;
determining, by the base station, a second plurality of mutual magnetic parameters, each mutual magnetic parameter of the second plurality of mutual magnetic parameters being associated with a different pair of transmitting coils of the plurality of transmitting coils;
determining, by the base station, a plurality of control signals based on the first plurality of mutual magnetic parameters and the second plurality of mutual magnetic parameters, each control signal of the plurality of control signals being associated with a corresponding transmitting coil of the plurality of transmitting coils;
providing each control signal of the plurality of control signals to a driving circuit coupled to the control signal's corresponding transmitting coil; and
using each control signal of the plurality of control signals to cause the driving circuit coupled to the control signal's corresponding transmitting coil to cause a current with a magnitude and phase determined from the control signal to flow in the corresponding transmitting coil.

2. The method of claim 1 wherein the at least one receiving coil includes a plurality of receiving coils.

3. The method of claim 2 further comprising determining, by the base station, a third plurality of mutual magnetic parameters, each mutual magnetic parameter of the third plurality of mutual magnetic parameters being associated with a different pair of receiving coils of the plurality of receiving coils, wherein determining the plurality of control signals if further based on the third plurality of mutual magnetic parameters.

4. The method of claim 1 wherein the plurality of control signals is determined to achieve a maximum wireless energy transfer to the at least one of the receiving coils subject to a power constraint at the base station.

5. The method of claim 1 further comprising receiving an indication of a power requirement at the base station from the electronic device, wherein determining the plurality of control signals is further based on the indication.

6. The method of claim 5 wherein the plurality of control signals is determined such that the power requirement is achieved at the receiver.

7. The method of claim 1 further comprising receiving an indication of an impedance at the receiver from the receiver, wherein determining the plurality of control signals is further based on the indication of the impedance at the receiver.

8. The method of claim 7 wherein the plurality of control signals is determined such that a power requirement is achieved at the receiver.

9. The method of claim 1 , wherein each mutual magnetic parameter comprises a mutual inductance.

10. The method of claim 1 , wherein each control signal of the plurality of control signals includes at least one of a coil current magnitude, a coil current phase, a coil voltage magnitude, and a coil voltage phase.

11. The method of claim 1 , further comprising receiving an indication that the electronic device is in a range for charging and needs to be charged from the electronic device prior to determining the mutual magnetic parameters.

12. The method of claim 11 , wherein said indication is based at least in part on the value of a load of the at least one receiving coil of the at least one electronic device.

13. The method of claim 1 , wherein the determining, providing, and using are repeated in a predefined time interval.

14. The method of claim 13 , wherein the predefined time interval is between two and ten seconds.

15. The method of claim 1 , wherein the determining, providing, and using are performed for any orientation of the electronic device relative to the base station.

16. The method of claim 1 , wherein the electronic device is a mobile phone, a smart phone, a tablet, a camera-phone or a portable computer.

17. A wireless energy transfer apparatus comprising:
a base station including a plurality of transmitting coils;
a plurality of driving circuits, each driving circuit of the plurality of driving circuits being coupled to a corresponding transmitting coil of the plurality of transmitting coils; and
a controller configured to:
determine a first plurality of mutual magnetic parameters, each mutual magnetic parameter of the first plurality of mutual magnetic parameters being associated with a transmitting coil of the plurality of transmitting coils and a receiving coil of at least one receiving coil associated with at least one electronic device remotely located from and to be remotely charged by the base station;
determine a second plurality of mutual magnetic parameters, each mutual magnetic parameter of the second plurality of mutual magnetic parameters being associated with a different pair of transmitting coils of the plurality of transmitting coils;
determine a plurality of control signals based on the first plurality of mutual magnetic parameters and the second plurality of mutual magnetic parameters, each control signal of the plurality of control signals being associated with a corresponding transmitting coil of the plurality of transmitting coils;
provide each control signal of the plurality of control signals to the driving circuit coupled to the control signal's corresponding transmitting coil; and
use each control signal of the plurality of control signals to cause the driving circuit coupled to the control signal's corresponding transmitting coil to cause a current with a magnitude and phase determined from the control signal to flow in the corresponding transmitting coil.

18. The wireless energy transfer apparatus of claim 17 wherein the at least one receiving coil includes a plurality of receiving coils.

19. The wireless energy transfer apparatus of claim 18 wherein the controller is further configured to determine a third plurality of mutual magnetic parameters, each mutual magnetic parameter of the third plurality of mutual magnetic parameters being associated with a different pair of receiving coils of the plurality of receiving coils, wherein determining the plurality of control signals if further based on the third plurality of mutual magnetic parameters.

20. The wireless energy transfer apparatus of claim 17 wherein the controller determines the plurality of control signals to achieve a maximum wireless energy transfer to the at least one of the receiving coils subject to a power constraint at the base station.

21. The wireless energy transfer apparatus of claim 17 wherein the controller receives an indication of a power requirement at the base station from the electronic device and determines the plurality of control signals based at least in part on the indication.

22. The wireless energy transfer apparatus of claim 21 wherein the controller determines the plurality of control signals such that the power requirement is achieved at the receiver.

23. The wireless energy transfer apparatus of claim 17 wherein the controller receives an indication of an impedance at the receiver from the receiver and the controller dete

Assignees

• Massachusetts Inst Technology

Inventors

• Jadidian Jouya
• Katabi Dina

Classifications

• H02J7/42

  with electronic devices having internal batteries, e.g. mobile phones · CPC title

• H02J7/90 Primary

  Regulation of charging or discharging current or voltage · CPC title

• H02J50/12

  of the resonant type · CPC title

• H02J50/10

  using inductive coupling · CPC title

• H02J50/80

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title