Calibration and assignment processes in wireless power transfer systems

• US 9,190,851 B2
• Filed: 03/30/2012
• Issued: 11/17/2015
• Est. Priority Date: 06/24/2011
• Status: Active Grant

• Current Assignee: Wit Co., Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Dukhyun, Lee, Yun Ho, Hur, Youngsik
• Primary Examiner(s): Berhanu, Samuel
• Application Number:
  US13/435,568
• Publication Number:
  US 20120326658A1
• Time in Patent Office: 1,327 Days
• Field of Search: 320/108
• US Class Current: 1/1
• CPC Class Codes: H02J 50/05 using capacitive coupling
• 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 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

Systems and methods pertaining to wireless power transfer are disclosed. Specifically, disclosed herein are calibration procedures that incorporate transmission of a reference power charge from a wireless power charger to permit determination of an optimized receiver circuitry configuration in one or more wirelessly chargeable devices. The result of the calibration procedures may then be used by the wireless charger to assign various frequencies to several wirelessly chargeable devices so as to optimally transfer a steady state power charge at one or more frequencies to the wirelessly chargeable devices.

Claims

1. A system comprising:

a wireless charger, comprising;

a first power charge transmitter; and

a controller unit operable to configure the first power charge transmitter to transmit a first reference wireless power charge at a first frequency, the first reference wireless power charge operative to permit one or more wirelessly chargeable devices to execute a calibration procedure; and

a first wirelessly chargeable device configured for executing the calibration procedure in the first wirelessly chargeable device, the first wirelessly chargeable device comprising;

a variable circuit element configured for executing a series of adjustments as a part of the calibration procedure to determine a first optimal setting whereby the first reference wireless power charge is optimally retrieved in the first wirelessly chargeable device; and

a storage device configured for storing a plurality of settings of the variable circuit element obtained during execution of the series of adjustments.

2. The system of claim 1, wherein the first wirelessly chargeable device further comprises:

a controller operable to access the storage device and identify the first optimal setting amongst the plurality of settings stored in the storage device.

3. The system of claim 2, wherein the variable circuit element is a capacitor and the plurality of settings stored in the storage device comprises a plurality of capacitance values.

4. The system of claim 1, wherein the wireless charger further comprises a second power charge transmitter;

and wherein the controller unit is further operable to configure the second power charge transmitter to transmit a second reference wireless power charge at a second frequency.

5. The system of claim 4, wherein the first wirelessly chargeable device is further configured to execute the calibration procedure for determining a second optimal setting of the variable circuit element whereby the second reference wireless power charge is optimally retrieved in the first wirelessly chargeable device.

6. The system of claim 5, wherein the wireless charger further comprises a wireless communication system configured to communicate with the first wirelessly chargeable device and direct the first wirelessly chargeable device to set the variable circuit element to one of the first or the second optimal setting based on at least one of:

a) calibration results data received in the wireless charger from the first wirelessly chargeable device or b) an assignment procedure implemented in the wireless charger.

7. The system of claim 6, wherein the wireless charger is configured to replace the first reference wireless power charge with a steady-state wireless power charge after a period of time, the steady-state wireless power charge using at least one of the first or the second frequency.

8. A method comprising:

transmitting from a wireless charger, a first reference wireless power charge at a first frequency for a first period of time, the first reference wireless power charge operative to permit one or more wirelessly chargeable devices to execute a calibration procedure associated with wireless power charging of the one or more wirelessly chargeable devices;

receiving the first reference wireless power charge in a first wirelessly chargeable device amongst the one or more wirelessly chargeable devices;

executing a calibration procedure for identifying an optimal retrieved power level in the first wirelessly chargeable device, the calibration procedure comprising;

manipulating a variable circuit element to provide “

N”

different impedances in a propagation path of the first reference wireless power charge;

obtaining “

N”

different retrieved power level measurements associated with providing the “

N”

different impedances in the propagation path of the first reference wireless power charge;

identifying the optimal retrieved power level measurement in the “

N”

different retrieved power level measurements; and

identifying a first impedance associated with the optimal retrieved power level measurement;

setting the variable circuit element to provide the first impedance in the propagation path of the steady-state wireless power charge received in the first wirelessly chargeable device after the first period of time;

discontinuing transmitting of the first reference wireless power charge after the first period of time; and

transmitting a steady-state wireless power charge at the first frequency for transferring power to the one or more wirelessly chargeable devices.

9. The method of claim 8, wherein providing the “

N”

different impedances in the propagation path of the first reference wireless power charge comprises providing the “

N”

different impedances in a tunable resonant circuit located in the first wirelessly chargeable device.

10. The method of claim 9, further comprising:

transmitting from the wireless charger, a second reference wireless power charge at a second frequency for a second period of time.

11. The method of claim 9, further comprising:

receiving the second reference wireless power charge in at least one of the first wirelessly chargeable device or a second wirelessly chargeable device amongst the one or more wirelessly chargeable devices; and

executing the calibration procedure in the at least one of the first or second wirelessly chargeable devices for identifying an optimal retrieved power level with reference to the second reference wireless power charge at the second frequency.

12. The method of claim 11, further comprising:

when the second reference wireless power charge is received in both the first and the second wirelessly chargeable devices, configuring one of the first or second wirelessly chargeable devices to prevent performing of the calibration procedure during execution of the calibration procedure in the other one of the first or the second wirelessly chargeable devices.

13. The method of claim 12, further comprising the wireless charger assigning the first frequency to the first wirelessly chargeable device and the second frequency to the second wirelessly chargeable device based on at least one of a) calibration results data received in the wireless charger from at least one of the first or second wirelessly chargeable devices or b) an assignment procedure implemented in the wireless charger.

14. The method of claim 13, further comprising the wireless charger defining a first group and a second group, the first group comprising the first wirelessly chargeable device, and the second group comprising the second wirelessly chargeable device.

15. The method of claim 14, wherein the wireless charger provides the steady-state wireless power charge at the first frequency and the steady-state wireless power charge at the second frequency in a time multiplexed format that is based on the defined first and second groups.

16. A system comprising:

a wireless charger configured to transmit a first reference wireless power charge at a first frequency, the first reference wireless power charge operative to permit one or more wirelessly chargeable devices to execute a calibration procedure prior to receiving a first steady-state wireless power charge from the wireless charger at the first frequency; and

further configured to transmit a second reference wireless power charge at a second frequency, the second reference wireless power charge operative to permit the one or more wirelessly chargeable devices to execute the calibration procedure prior to receiving a second steady-state wireless power charge from the wireless charger at the second frequency, wherein the first reference wireless power charge is transmitted during a first period of time that at least partially overlaps a second period of time during which the second reference wireless power charge is transmitted.