Wireless power transfer method, apparatus and system

• US 10,256,666 B2
• Filed: 02/06/2015
• Issued: 04/09/2019
• Est. Priority Date: 02/07/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Jung, Byungsang, Lee, Hyunbeom, Lee, Seonghun, Park, Yongcheol
• Primary Examiner(s): Deberadinis, Robert
• Application Number:
  US15/101,826
• Publication Number:
  US 20160308397A1
• Time in Patent Office: 1,523 Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

The present disclosure relates to a wireless power reception method, a wireless power reception apparatus, and a wireless charging system in a wireless power transmission and reception field, and the wireless power reception apparatus may include a power receiving unit configured to change a magnetic flux to a current to receive power in a wireless manner, and a power controller connected to the power receiving unit to change a resonant frequency to control power received from the power receiving unit, wherein the power controller includes a first capacitor, a second capacitor connected to the first capacitor in parallel, a first switch connected to the second capacitor in series to flow a current in a first direction, a second switch configured to flow a current in a second direction opposite to the first direction, and a switch controller configured to control the first and the second switch.

Claims

1. A wireless power transmitter for transmitting power in a wireless manner, the wireless power transmitter comprising:

a power transmission unit having a plurality of coils configured to change a current to a magnetic flux to transmit power in a wireless manner, a plurality of sub-half bridge inverters connected to the plurality of coils, respectively, and a main half bridge inverter connected to all the plurality of sub-half bridge inverters; and

a power transmission controller configured to control at least one coil to transmit power to a wireless power receiver using at least one of the plurality of coils,

wherein the power transmission controller performs a full bridge inverter control based on at least one sub-half bridge inverter connected to the at least one coil and the main half bridge inverter.

2. The wireless power transmitter of claim 1, wherein the power transmission controller controls power through a phase difference of voltage for the sub-half bridge inverter based on a reference voltage for the main half bridge inverter.

3. The wireless power transmitter of claim 2, wherein the power transmission controller transmits maximum power to the wireless power receiver when a voltage for the main half bridge inverter and a voltage for the sub-half bridge inverter have a phase difference of 180 degrees.

4. The wireless power transmitter of claim 2, wherein a voltage for the sub-half bridge inverter is determined by an amount of power transmitted from a coil connected to the sub-half bridge inverter.

5. The wireless power transmitter of claim 1, wherein the power transmission controller controls voltages for a plurality of sub-half bridge inverters connected to the at least one coil to have different voltages.

6. The wireless power transmitter of claim 1, wherein the power transmission controller controls a sub-half bridge inverter to allow a voltage for the sub-half bridge inverter connected to a coil that does not transmit power among the plurality of coils to have the same phase as a reference voltage for the main half bridge inverter.

7. The wireless power transmitter of claim 1, wherein the power transmission controller controls the main-half bridge inverter based on a first pulse with modulation (PWM), and controls the sub-half bridge inverter based on a second PWM whose phase is different from the first PWM.

8. The wireless power transmitter of claim 7, wherein the power transmission controller sets the second PWM as an initial PWM when the power transmission controller detects the wireless power receiver.

9. The wireless power transmitter of claim 8, wherein the power transmission controller sets the second PWM as a phase shifted PWM when the power transmission controller transmits power to the wireless power receiver.

10. A control method of wireless power transmitter for transmitting power, the wireless power transmitter including a plurality of coils configured to change a current to a magnetic flux to transmit power in a wireless manner, a plurality of sub-half bridge inverters connected to the plurality of coils, respectively, and a main half bridge inverter connected to all the plurality of sub-half bridge inverters, the method comprising:

performing a full bridge inverter control based on at least one sub-half bridge inverter connected to at least one coil and the main half bridge inverter; and

controlling the at least one coil to transmit power to a wireless power receiver using at least one of the plurality of coils.

11. The method of claim 10, wherein the full bridge inverter control includes controlling power through a phase difference of voltage for the sub-half bridge inverter based on a reference voltage for the main half bridge inverter.

12. The method of claim 11, further comprising:

transmitting maximum power to the wireless power receiver when a voltage for the main half bridge inverter and a voltage for the sub-half bridge inverter have a phase difference of 180 degrees.

13. The method of claim 11, wherein a voltage for the sub-half bridge inverter is determined by an amount of power transmitted from a coil connected to the sub-half bridge inverter.

14. The method of claim 10, wherein the full bridge inverter control includes controlling voltages for a plurality of sub-half bridge inverters connected to the at least one coil to have different voltages.

15. The method of claim 10, wherein the full bridge inverter control includes controlling a sub-half bridge inverter to allow a voltage for the sub-half bridge inverter connected to a coil that does not transmit power among the plurality of coils to have the same phase as a reference voltage for the main half bridge inverter.

16. The method of claim 10, wherein the full bridge inverter control includes controlling the main-half bridge inverter based on a first pulse with modulation (PWM), and controlling the sub-half bridge inverter based on a second PWM whose phase is different from the first PWM.

17. The method of claim 16, wherein the full bridge inverter control includes setting the second PWM as an initial PWM when the power transmission controller detects the wireless power receiver.

18. The method of claim 17, wherein the full bridge inverter control includes setting the second PWM as a phase shifted PWM when the power transmission controller transmits power to the wireless power receiver.