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; and
a communication unit configured to receive control data from the wireless power reception device via the primary coil; and
a control unit configured to:
control a transmission of the wireless power to the wireless power reception device based, at least in part, on the control data received from the wireless power reception device, and
set an operation point for the transmission of the wireless power via the primary coil based, at least in part, on a control error value when the control data comprises a control error packet (CEP) that includes the control error value.
2. The wireless power transmission device of claim 1 , wherein the control error value is received in the CEP from the wireless power reception device.
3. The wireless power transmission device of claim 2 , wherein the CEP is received via a received signal from the wireless power reception device, the wireless power transmission device further comprising:
the control unit configured to reset a CEP timer when the communication unit receives the CEP and to count an interrupt generated when decoding the received signal,
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 and the interrupt count.
4. The wireless power transmission device of claim 3 , wherein the CEP timer indicates whether the CEP is received within a predetermined period.
5. The wireless power transmission device of claim 3 ,
wherein the control unit stops the transmission of the wireless power when the CEP timer is expired and the interrupt count is not greater than a reference value,
wherein the control unit continues the transmission of the wireless power and resets the CEP timer when the CEP timer is expired and the interrupt count is greater than the reference value, and
wherein the control unit increases a CEP decoding failure count when the CEP timer is expired and the interrupt count is not greater than the reference value.
6. The wireless power transmission device of claim 1 , wherein the control unit is further configured to:
end the transmission of the wireless power via the primary coil when the control data comprises an 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 the 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; and
receiving control data from the wireless power reception device via the primary coil;
controlling a transmission of the wireless power to the wireless power reception device based, at least in part, on the control data received from the wireless power reception device; and
setting an operation point for the transmission of the wireless power via the primary coil based, at least in part, on a control error value when the control data comprises a control error packet (CEP) that includes the control error value.
10. The method of claim 9 , wherein the control error value is received in the CEP from the wireless power reception device.
11. The method of claim 10 , wherein the CEP is received via a received signal from the wireless power reception device, the method further comprising:
resetting a CEP timer when the wireless power transmission device receives the CEP and counting an interrupt generated when decoding the received signal; and
controlling or stopping the transmission of the wireless power to the wireless power reception device based on the CEP timer and the interrupt count.
12. The method of claim 11 , wherein the CEP timer indicates whether the CEP is received within a predetermined period.
13. The method of claim 11 , wherein controlling or stopping the transmission of the wireless power includes:
stopping the transmission of the wireless power when the CEP timer is expired and the interrupt count is not greater than a reference value;
continuing the transmission of the wireless power and resetting the CEP timer when the CEP timer is expired and the interrupt count is greater than the reference value; and
increasing a CEP decoding failure count when the CEP timer is expired and the interrupt count is not greater than the reference value.
14. The method of claim 9 , further comprising:
ending the transmission of the wireless power via the primary coil when the control data comprises an 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 the wireless power.
16. The method of claim 15 , wherein the reason includes at least one of charge complete, over temperature, over voltage, or over current.