Power control method and device in wireless power transmission system
The present invention relates to a power control method and device in a wireless power transmission system. According to the present invention, even if a CEP packet is not transmitted from a wireless power reception device over a certain period of time, a wireless power transmission device may additionally determine whether the wireless power reception device is located in a charging area and sustainably perform charging.
1. A wireless power transmission device comprising:
at least one primary coil configured to transmit wireless power to a wireless power reception device;
a communication unit configured to communicate a data packet message to the wireless power reception device via the primary coil or a radio frequency (RF) communication unit, the communication unit configured to receive a control error packet (CEP) including a control error value from the wireless power reception device via the at least one primary coil; and
a control unit configured to control an operation point for a transmission of wireless power to the wireless power reception device via the primary coil based, at least in part, on the control error value.
2. The wireless power transmission device of claim 1 , further comprising:
the control unit configured to reset a CEP timer when the communication unit receives the CEP,
the control unit configured to control or stop the transmission of the wireless power to the wireless power reception device based on the CEP timer.
3. The wireless power transmission device of claim 2 , wherein the CEP timer indicates whether the CEP is received within a predetermined period.
4. The wireless power transmission device of claim 3 ,
wherein the control unit is configured to stop the transmission of the wireless power when the CEP timer is expired, and
wherein the control unit is configured to continue the transmission of the wireless power and reset the CEP timer when a new CEP is received.
5. The wireless power transmission device of claim 4 ,
wherein the control unit is configured to count an interrupt generated when decoding a received signal from the wireless power reception device, and
wherein the control unit is configured to continue the transmission of the wireless power and reset the CEP timer when the CEP timer is expired and the interrupt count is greater than a reference value.
6. The wireless power transmission device of claim 1 ,
wherein the communication unit is further configured to receive and decode an end power transfer packet from the wireless power reception device, and
wherein the control unit is further configured to end the transmission of wireless power via the primary coil when the communication unit receives and decodes the end power transfer packet.
7. The wireless power transmission device of claim 6 , wherein the end power transfer packet includes information that indicates a reason for requesting an end of the transmission of wireless power.
8. The wireless power transmission device of claim 7 , wherein the reason includes at least one of charge complete, over temperature, over voltage, or over current.
9. A method performed by a wireless power transmission device, the method comprising:
transmitting wireless power to a wireless power reception device via at least one primary coil;
communicating a data packet message to the wireless power reception device via the primary coil or a radio frequency (RF) communication unit;
receiving a control error packet (CEP) including a control error value from the wireless power reception device via the at least one primary coil; and
controlling an operation point for a transmission of wireless power to the wireless power reception device via the primary coil based, at least in part, on the control error value.
10. The method of claim 9 , further comprising:
resetting a CEP timer when the CEP is received from the wireless power reception device; and
controlling or stopping the transmission of the wireless power to the wireless power reception device based on the CEP timer.
11. The method of claim 10 , wherein the CEP timer indicates whether the CEP is received within a predetermined period.
12. The method of claim 11 ,
stopping the transmission of the wireless power when the CEP timer is expired; and
continuing the transmission of the wireless power and resets the CEP timer when a new CEP is received.
13. The method of claim 12 , further comprising:
counting an interrupt generated when decoding a received signal from the wireless power reception device; and
continuing the transmission of the wireless power and reset the CEP timer when the CEP timer is expired and the interrupt count is greater than a reference value.
14. The method of claim 9 ,
receiving and decoding an end power transfer packet from the wireless power reception device, and
ending the transmission of wireless power via the primary coil when the communication unit receives and decodes the end power transfer packet.
15. The method of claim 14 , wherein the end power transfer packet includes information that indicates a reason for requesting an end of the transmission of wireless power.