WIRELESS POWER TRANSMITTER AND METHOD OF CONTROLLING POWER THEREOF

• US 20140084701A1
• Filed: 09/26/2013
• Published: 03/27/2014
• Est. Priority Date: 09/26/2012
• Status: Active Grant

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: BAE, Su Ho
• Granted Patent: US 10,163,564 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

Disclosed are a wireless power transmitter and a method of controlling power thereof. A wireless power transmitter includes a power supply device to supply AC power to the wireless power transmitter; and a transmission coil to transmit the AC power to a reception coil of a wireless power receiver by resonance. The wireless power transmitter controls transmission power to be transmitted to the wireless power receiver based on a coupling state between the transmission coil and the reception coil.

Claims

1. A wireless power transmitter comprising:

a power supply unit to supply AC power to the wireless power transmitter; and

a transmission coil to transmit the AC power to a reception coil of a wireless power receiver by resonance,

wherein the wireless power transmitter controls transmission power to be transmitted to the wireless power receiver based on a coupling state between the transmission coil and the reception coil.

2. The wireless power transmitter of claim 1, wherein the wireless power transmitter decides a first reception power to be received by a load according to the coupling state and controls the transmission power such that the decided first reception power is transmitted to the load.

3. The wireless power transmitter of claim 2, wherein the wireless power transmitter determines a second reception power, which is presently received by the load, and controls the transmission power such that the first reception power is transmitted to the load if the second reception power is different from the first reception power.

4. The wireless power transmitter of claim 3, wherein the coupling state is a coupling coefficient between the transmission coil and the reception coil, and the wireless power transmitter determines the second reception power by detecting the coupling coefficient.

5. The wireless power transmitter of claim 4, wherein the wireless power transmitter determines the second reception power through in-band communication or out-of-band communication with the wireless power receiver.

6. The wireless power transmitter of claim 1, further comprising a detection unit to detect a coupling state between the wireless power transmitter and the wireless power receiver.

7. The wireless power transmitter of claim 6, wherein the coupling state is a coupling coefficient between the transmission coil and the reception coil, and

the detection unit measures an input impedance obtained when viewed from the power supply device to the wireless power transmitter and detects the coupling coefficient based on the measured input impedance.

8. The wireless power transmitter of claim 7, wherein the detection unit detects the coupling state by measuring an input impedance of the wireless power transmitter after fixing an output impedance of the wireless power receiver.

9. The wireless power transmitter of claim 7, further comprising a storage unit to store the coupling coefficient and the transmission power corresponding to each other, wherein the wireless power transmitter searches for the transmission power corresponding to the detected coupling coefficient to transmit the searched transmission power to the wireless power receiver.

10. The wireless power transmitter of claim 1, wherein the power supply unit receives DC power from a power supply unit to output the AC power, and the wireless power transmitter controls the transmission power by adjusting the AC power output from the power supply unit.

11. The wireless power transmitter of claim 10, wherein the power supply unit transmits a power control signal to control the DC power output from the power supply unit through power line communication.

12. The wireless power transmitter of claim 1, wherein the power supply unit comprises an AC power generating unit to generate the AC power by receiving the DC power from the power supply unit, and

the wireless power transmitter determines the coupling state based on an intensity of current input to the AC power generating unit or output from the AC power generating unit and controls the transmission power according to the determined coupling state.

13. A method of controlling power of a wireless power transmitter, the method comprising:

detecting a coupling state between the wireless power transmitter and a wireless power receiver;

adjusting transmission power based on the coupling state; and

transmitting the adjusted transmission power to a load by resonance.

14. The method of claim 13, wherein the adjusting of the transmission power comprises:

determining a first reception power to be received by the load corresponding to the coupling state; and

adjusting the transmission power such that the determined first reception power is transmitted to the load.

15. The method of claim 14, wherein the adjusting of the transmission power such that the determined first reception power is transmitted to the load comprises,

determining a second reception power presently received by the load,

comparing the first reception power with the second reception power and,

adjusting the transmission power such that the first reception power is transmitted to the load if the first reception power is different from the second reception power as a comparison result.

16. The method of claim 15, wherein the determining of the second reception power, which is presently received by the load, comprises determining the second reception power through in-band communication or out-of-band communication with the wireless power receiver.

17. The method of claim 15, wherein the determining of the second reception power presently received by the load comprises determining the second reception power by measuring an intensity of current flowing inside the power supply device.

18. The method of claim 13, wherein the detecting of the coupling state comprises detecting a coupling coefficient between a transmission coil of the wireless power transmitter and a reception coil of the wireless power receiver.

19. The method of claim 18, wherein the adjusting of the transmission power comprises determining the transmission power by searching a storage unit to store the coupling coefficient and the transmission power corresponding to the coupling coefficient.

20. The method of claim 13, wherein the detecting of the coupling state comprises detecting the coupling state by using an input impedance of the wireless power transmitter.