WIRELESS POWER TRANSMITTER AND METHOD OF CONTROLLING THE SAME

• US 20130099734A1
• Filed: 10/24/2012
• Published: 04/25/2013
• Est. Priority Date: 10/24/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Kyung-Woo, Kim, Hong-Kweun
• Granted Patent: US 9,496,741 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• 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 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

A method and apparatus for controlling wireless transmission to a wireless power receiver in a wireless power transmitter is provided. The method includes transmitting charging power to the wireless power receiver; detecting whether a predetermined power tracking triggering event for adjusting an applied transmission power according to power information of the wireless power receiver occurs; and adjusting, upon determining that the predetermined triggering event has occurred, the applied transmission power.

Claims

1. A method of controlling wireless transmission to a wireless power receiver in a wireless power transmitter, the method comprising:

transmitting charging power to the wireless power receiver;

detecting whether a predetermined power tracking triggering event for adjusting an applied transmission power based on power information of the wireless power receiver occurs; and

adjusting, upon determining that the predetermined triggering event has occurred, the applied transmission power.

2. The method of claim 1, wherein adjusting the applied transmission power, comprises,

increasing the applied transmission power to a first power;

decrementing the first power step by step until a voltage at the wireless power receiver meets a predetermined threshold; and

when the voltage at the wireless power receiver meets the predetermined threshold, fixing the applied transmission power.

3. The method of claim 1, wherein the voltage at the wireless power receiver includes a voltage at an input end or an output end of a Direct Current (DC) to DC converter of the wireless power receiver.

4. The method of claim 3, wherein a predetermined threshold for the voltage at the input end of the DC to DC converter of the wireless power receiver ranges from 5.2V to 5.5V, and a predetermined threshold for the voltage at the output end of the DC to DC converter of the wireless power receiver is 5V.

5. The method of claim 3, further comprising:

transmitting a command signal to instruct the wireless power receiver to report the power information; and

receiving, from the wireless power receiver, a report signal including the power information of the wireless power receiver in response to the command signal.

6. The method of claim 5, wherein the command signal comprises at least one piece of information about a session IDentifier (ID) of the wireless power receiver, a sequence number, a network ID of the wireless power transmitter, a command type, and extra information of the command type.

7. The method of claim 6, wherein the command type indicates that the command signal is an instruction to report the power information of the wireless power receiver.

8. The method of claim 5, wherein the report signal includes at least one of a session IDentifier (ID) of the wireless power receiver, a sequence number, a network ID of the wireless power transmitter, a voltage applied at the input end of the DC to DC converter of the wireless power receiver, a voltage applied at the output end of the DC to DC converter of the wireless power receiver, and a current passing through the output end of the DC to DC converter of the wireless power receiver.

9. The method of claim 1, wherein the predetermined triggering event occurs when a new wireless power receiver is registered in the wireless power transmitter and the wireless power transmitter transmits a command signal to start charging to the new wireless power receiver.

10. The method of claim 1, wherein the predetermined triggering event occurs when the wireless power receiver is rearranged or withdrawn and a corresponding load change is detected by the wireless power transmitter.

11. The method of claim 1, wherein the predetermined triggering event occurs when the wireless power transmitter has a wireless power transmission efficiency with respect to the wireless power receiver that is less than a predetermined threshold.

12. The method of claim 1, wherein the predetermined triggering event occurs when a voltage at an input end or output end of a DC to DC converter of the wireless power receiver is less than a predetermined threshold.

13. The method of claim 2, wherein the decrementing of the first power step by step comprises,

maintaining an optimal wireless power transmission efficiency by performing impedance matching of the wireless power transmitter.

14. The method of claim 2, wherein the decrementing of the first power step by step comprises, decreasing power applied to an amplifier of the wireless power transmitter.

15. The method of claim 1, further comprising:

transmitting, for each cycle, a Notice signal to the wireless power receiver, the notice signal having at least one of information of a protocol version of the wireless power transmitter, a sequence number, a network IDentifier (ID), information about a wireless power receiver to do a report, and information about a number of managed wireless power receivers.

16. The method of claim 15, wherein the decrementing of the first power step by step comprises decrementing a voltage of the first power by a step for a predetermined period of time.

17. The method of claim 1, wherein a voltage of the first power is two steps higher than a voltage of the applied transmission power.

18. A wireless power transmitter for wirelessly transmitting power to a wireless power receiver, the wireless power transmitter comprising:

a power transmitter for transmitting charging power to the wireless power receiver;

a communication unit for receiving power information of the wireless power receiver; and

a controller for detecting whether a predetermined power tracking triggering event for adjusting an applied transmission power according to the power information of the wireless power receiver occurs, and adjusting, upon determining that the predetermined triggering event has occurred, the applied transmission power.

19. The wireless power transmitter of claim 18, wherein the controller increases the applied transmission power to a first power upon determining that the predetermined triggering event occurs, decrements a voltage at the first power step by step until a voltage of the wireless power receiver meets a predetermined threshold, and when the voltage at the wireless power receiver meets the predetermined threshold, fixes the decreased applied transmission power.

20. The wireless power transmitter of claim 19, wherein the voltage at the wireless power receiver comprises a voltage at an input end or an output end of a Direct Current (DC) to DC converter of the wireless power receiver.

21. The wireless power transmitter of claim 18, further comprising:

an impedance matching unit for maintaining an optimal wireless power transmission efficiency by performing impedance matching of the wireless power transmitter.

22. The wireless power transmitter of claim 21, wherein the impedance matching unit includes at least one of at least one switch, at least one coil, and at least one capacitor.

23. The wireless power transmitter of claim 18, further comprising:

a power supplier for supplying power; and

an amplifier for amplifying the power with a predetermined gain,

wherein the controller decreases a power applied to the amplifier.

24. The wireless power transmitter of claim 18, wherein the communication unit transmits, for each cycle, a Notice signal to the wireless power receiver, the notice signal having at least one of information of a protocol version of the wireless power transmitter, a sequence number, a network IDentifier (ID), information about a wireless power receiver to do a report, and information about a number of managed wireless power receivers.

25. The wireless power transmitter of claim 24, wherein the controller decrements a voltage of the first power by a step for each of a predetermined period of time.

26. The wireless power transmitter of claim 18, wherein a voltage of the first power is two steps higher than a voltage of the applied transmission power.