WIRELESS POWER TRANSMISSION DEVICE AND CONTROL METHOD THEREFOR

• US 20160241086A1
• Filed: 09/23/2014
• Published: 08/18/2016
• Est. Priority Date: 10/31/2013
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: JUNG, Byungsang, CHAE, Beomseok, PARK, Yongcheol, KIM, Kyunghwan
• Granted Patent: US 10,097,041 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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

Abstract

The present specification which relates to a wireless power transmission device and a control method, capable of transmitting and receiving power wirelessly comprises a power supply unit for supplying power to a receiving device to transmit power wirelessly; and a power transmission control unit for, periodically generating a waveform with a particular frequency, measuring an attenuation coefficient of the waveform at each cycle, measuring a variation in the attenuation coefficient at each cycle, and determining the type of an external material. The present invention has a technical feature wherein the power transmission control unit determines whether to transmit power wirelessly to the receiving device on the basis of the type of the external material.

Claims

1. A wireless power transmitter capable of transmitting and receiving power in a wireless manner, the wireless power transmitter comprising:

a power supply unit configured to supply power to transmit power to a receiver in a wireless manner; and

a power transmission control unit configured to periodically generate a waveform at a specific frequency to measure an attenuation factor of the waveform for each period, and measure a variation of the attenuation factor for the each period to determine the type of an external material,

wherein the power transmission control unit determines whether or not to transmit power to the receiver in the wireless manner based on the type of the external material.

2. The wireless power transmitter of claim 1, wherein the power transmission control unit detects a variation of an attenuation factor changed according to the period of the waveform, and determines the external material as a receiver that receives power in the wireless manner to transmit power to the receiver in a wireless manner when the variation of the attenuation factor corresponds to a preset reference variation.

3. The wireless power transmitter of claim 2, further comprising:

a wireless communication unit formed to perform communication with the receiver in a wireless manner,

wherein the power transmission control unit transmits a preset amount of power and control information associated with communication to the receiver to perform communication through the wireless communication unit when the external material is a receiver that receives the wireless power.

4. The wireless power transmitter of claim 3, wherein the power transmission control unit transmits power to the receiver in a wireless manner when one-to-one communication with the receiver is completed.

5. The wireless power transmitter of claim 4, wherein the power transmission control unit receives amount-of-power information on wireless power to be received from the receiver through the connected communication to control the power supply unit so as to supply power based on the amount-of-power information.

6. The wireless power transmitter of claim 5, wherein the power transmission control unit suspends power that has been supplied to the receiver upon receiving alignment state information indicating that the alignment state of the receiver has been changed from the receiver through the connected communication.

7. The wireless power transmitter of claim 1, wherein when a frequency different from a preset resonant frequency is detected subsequent to periodically generating the waveform at the specific frequency, the power transmission control unit determines the type of an external material based on the characteristics of the different frequency.

8. The wireless power transmitter of claim 7, wherein the power transmission control unit detects the type of the external material based on the characteristics of the different frequency, and determines an amount of power to be transmitted in a wireless manner based on the type of the external material.

9. The wireless power transmitter of claim 7, wherein the power transmission control unit detects a capacitance of the external material based on a variation of the attenuation factor of the different frequency.

10. A wireless charging system, comprising:

a transmitter formed to transmit power in a wireless manner; and

a receiver formed to receive wireless power from the transmitter,

wherein the transmitter comprises;

a power supply unit configured to supply power to transmit power to the receiver in a wireless manner; and

a power transmission control unit configured to periodically generate a waveform at a specific frequency to measure an attenuation factor of the waveform for each period, and measure a variation of the attenuation factor for the each period to determine whether or not to transmit power in a wireless manner to the receiver.

11. The wireless charging system of claim 10, further comprising:

a wireless communication unit formed to perform communication with the receiver in a wireless manner,

wherein the power transmission control unit transmits communication information and a preset amount of power to the receiver to perform communication with the receiver in a wireless manner prior to transmitting power to the receiver in a wireless manner.

12. The wireless charging system of claim 11, wherein the power transmission control unit transmits the communication information and preset amount of power using a frequency higher than a resonant frequency of the transmitter.

13. The wireless charging system of claim 11, wherein when communication is connected to the receiver based on the communication information, the power transmission control unit controls the power supply unit to transmit power based on an amount of power received from the receiver through the communication.

14. The wireless charging system of claim 13, wherein when a request signal for suspending power transmission is received from the receiver, the power transmission control unit controls the power supply unit to suspend the power being transmitted.

15. The wireless charging system of claim 14, wherein the receiver generates the request signal based on at least one of a voltage value, a voltage drop time and a current value of the receiver.

16. A wireless power transmission method of a wireless power transmitter for transmitting power in a wireless manner, the wireless power transmission method comprising:

periodically generating a waveform at a specific frequency;

sensing a power receiver that receives power in a wireless manner based on a variation of an attenuation factor for each period of the waveform at the specific frequency;

transferring communication connection information and power to be used for a communication module of a receiver to the power receiver to communicate with the transmitter when the power receiver is detected;

connecting communication to the receiver using the communication connection information; and

receiving amount-of-power information to be transmitted from the receiver in a wireless manner using the connected communication, and transmitting power in a wireless manner based on the received amount-of-power information,

wherein said sensing the power receiver periodically generates the waveform at the specific frequency, and measures an attenuation factor for the period to detect a receiver using a variation of a plurality of attenuation factors.

17. The wireless power transmission method of claim 16, wherein said sensing the power receiver determines an alignment state of the receiver using a waveform having a frequency different from a resonant frequency of the transmitter.

18. The wireless power transmission method of claim 16, wherein said transferring the communication connection information to the power receiver transfers the communication connection information using a frequency higher than that of a resonant frequency of the transmitter.

19. The wireless power transmission method of claim 16, wherein the transmitter communicates with the receiver in a one-to-one manner.

20. The wireless power transmission method of claim 16, wherein said transmitting power to the receiver in a wireless manner suspends the transmission of the power based on a request signal for suspending the transmission of power that is received from the receiver through the communication.