Systems and methods for controlling wireless power transfer

Patent metadata

Field	Value
Publication number	US-2017237293-A1
Application number	US-201615043786-A
Country	US
Kind code	A1
Filing date	Feb 15, 2016
Priority date	Feb 15, 2016
Publication date	Aug 17, 2017
Grant date	—

Abstract

A system and method for wireless power transfer. The system includes a transmit coil having a first magnetic field having a first magnitude. The system also includes a receive coil, magnetically coupled to the transmit coil, having a second magnetic field having a second magnitude. The system also includes an electronic processor electrically coupled to the transmit coil and communicatively coupled to the receive coil. The electronic processor is configured to determine the first magnitude of the first magnetic field. The electronic processor is further configured to receive the second magnitude of the second magnetic field. The electronic processor is further configured to determine an efficiency based on the first magnitude and the second magnitude, and determine a power level for the transmit coil based on the efficiency.

First claim

We claim:

1 . A method for controlling a wireless power transfer system, the method comprising:
generating, with a transmit coil, a first magnetic field having a first magnitude; magnetically coupling a receive coil to the transmit coil to generate a second magnetic field having a second magnitude; determining, by an electronic processor electrically coupled to the transmit coil and communicatively coupled to the receiving coil, at least one selected from the group consisting of the first magnitude of the first magnetic field and a first current magnitude of a current in the transmit coil; receiving, by the electronic processor, at least one selected from the group consisting of the second magnitude of the second magnetic field and a second current magnitude of a current in the receive coil; determining, by the electronic processor, an efficiency based on at least one of the group consisting of the first magnitude, the second magnitude, the first current magnitude, and the second current magnitude; and determining, by the electronic processor, a power level for the transmit coil based on the efficiency.

2 . The method of claim 1 , wherein determining an efficiency includes determining a ratio based on the first magnitude and the second magnitude.

3 . The method of claim 1 , wherein determining an efficiency includes determining a ratio based on the first current magnitude and the second current magnitude.

4 . The method of claim 1 , further comprising:
generating, with a radiofrequency amplifier, a plurality of diagnostic current bursts.

5 . The method of claim 1 , further comprising:
adjusting, by the electronic processor, based on the efficiency, at least one of a group consisting of a first impedance for the transmit coil and a second impedance for the receive coil.

6 . The method of claim 1 , further comprising:
determining, by the electronic processor, a first phase of the first magnetic field; receiving, by the electronic processor, a second phase of the second magnetic field; determining, by the electronic processor, a phase difference based on the first and second phases; and determining, by the electronic processor, a coil alignment based on the phase difference.

7 . The method of claim 6 , further comprising:
determining, by the electronic processor, a power level for the transmit coil based on the coil alignment.

8 . The method of claim 6 , further comprising:
determining, by the electronic processor, a power level for the transmit coil based on the efficiency and the coil alignment.

9 . The method of claim 6 , further comprising:
adjusting, by the electronic processor, at least one of a group consisting of a first impedance for the transmit coil and a second impedance for the receive coil, based on the efficiency and the coil alignment.

10 . A wireless power transfer system, the system comprising:
a transmit coil having a first magnetic field having a first magnitude; a receive coil, magnetically coupled to the transmit coil, having a second magnetic field having a second magnitude; and an electronic processor electrically coupled to the transmit coil and communicatively coupled to the receive coil, and configured to determine at least one selected from the group consisting of the first magnitude of the first magnetic field and a first current magnitude of a current in the transmit coil; receive at least one selected from the group consisting of the second magnitude of the second magnetic field and a second current magnitude of a current in the receive coil; determine an efficiency based on at least one of the group consisting of the first magnitude, the second magnitude, the first current magnitude, and the second current magnitude; and determine a power level for the transmit coil based on the efficiency.

11 . The system of claim 10 , wherein the electronic processor is further configured to determine a ratio based on the first magnitude and the second magnitude.

12 . The system of claim 10 , wherein the electronic processor is further configured to determine a ratio based on the first current magnitude and the second current magnitude.

13 . The system of claim 10 , further comprising:
a radiofrequency amplifier electrically coupled to the electronic processor, wherein the electronic processor is further configured to generate, with the radiofrequency amplifier, a plurality of diagnostic current bursts.

14 . The system of claim 10 , further comprising:
a first impedance matching network electrically coupled to the electronic processor; and a second impedance matching network communicatively coupled to the electronic processor, wherein the electronic processor is further configured to adjust, based on the efficiency, at least one of a group consisting of a first impedance for first impedance matching network and a second impedance for the second impedance matching network.

15 . The system of claim 10 , wherein the electronic processor is further configured to
determine a first phase of the first magnetic field; receive a second phase of the second magnetic field; determine a phase difference based on the first and second phases; and determine a coil alignment based on the phase difference.

16 . The system of claim 15 , wherein the electronic processor is further configured to determine a power level for the transmit coil based on the coil alignment.

17 . The system of claim 15 , wherein the electronic processor is further configured to determine a power level for the transmit coil based on the efficiency and the coil alignment

18 . The system of claim 15 , further comprising:
a first impedance matching network electrically coupled to the electronic processor; and a second impedance matching network communicatively coupled to the electronic processor, wherein the electronic processor is further configured to adjust, based on the efficiency and the coil alignment, at least one of a group consisting of a first impedance for first impedance matching network and a second impedance for the second impedance matching network.

Assignees

• Motorola Solutions Inc

Inventors

• Faraone Antonio
• Bit-Babik Giorgi G
• Tran Chi T

Classifications

• H02J50/90 Primary

  involving detection or optimisation of position, e.g. alignment · CPC title

• H02J50/12 Primary

  of the resonant type · CPC title

• H02J50/80 Primary

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

• G06F1/26

  Power supply means, e.g. regulation thereof (for memories G11C) · CPC title