Wireless power transmitting apparatus and method thereof

Abstract

Disclosed are a wireless power transmitting apparatus and a method thereof. The wireless power transmitting apparatus wirelessly transmits power to a wireless power receiving apparatus. The wireless power transmitting apparatus detects a wireless power transmission state between the wireless power transmitting apparatus and the wireless power receiving apparatus, and generates a control signal to control transmit power based on the detected wireless power transmission state. The wireless power transmitting apparatus generates the transmit power by using first DC power based on the control signal, and transmits the transmit power to a transmission resonance coil through a transmission induction coil unit based on an electromagnetic induction scheme.

What is claimed is: 
     
       1. A wireless power transmitting apparatus wirelessly transmitting power to a wireless power receiving apparatus, the wireless power transmitting apparatus comprising:
 a detector detecting a wireless power transmission state between the wireless power transmitting apparatus and the wireless power receiving apparatus;   a transmit power controller generating a control signal to control transmit power based on the detected wireless power transmission state;   an AC power generator generating an AC power using a first DC power, wherein the generated AC power is determined based on the control signal; and   a transmission coil unit transmitting the AC power to the wireless power receiving apparatus;   wherein the AC power generator comprises:   a DC-DC converter converting the first DC power into a second DC power, wherein the second DC power is determined based on the control signal; and   a DC-AC converter converting the second DC power into the AC power;   wherein the detector detects the wireless power transmission state based on a level of an output current of the DC-DC converter, and   wherein the detector detects the wireless power transmission state based on a peak-to-peak level of the output current of the DC-DC converter.   
     
     
       2. The wireless power transmitting apparatus of  claim 1 , wherein the transmit power controller comprises a DC power generation controller generating a DC power generation control signal based on the detected wireless power transmission state, and
 wherein the second DC power is determined based on the DC power generation control signal.   
     
     
       3. The wireless power transmitting apparatus of  claim 2 , wherein the DC power generation controller changes a duty cycle of the DC power generation control signal based on the detected wireless power transmission state. 
     
     
       4. The wireless power transmitting apparatus of  claim 1 , wherein the DC-AC converter comprises a transistor circuit unit including a half-bridge structure. 
     
     
       5. The wireless power transmitting apparatus of  claim 1 , wherein the AC power generator comprises a full-bridge transistor circuit unit capable of operating at a half-bridge operating mode and a full-bridge operating mode,
 wherein the transmit power controller comprises an AC power generation controller selecting one of the half-bridge operating mode or the full-bridge operating mode based on the detected wireless power transmission state, and generating an AC power generation control signal corresponding to the selected operating mode, and   wherein the full-bridge transistor circuit unit converts the second DC power into the AC power based on the AC power generation control signal.   
     
     
       6. The wireless power transmitting apparatus of  claim 5 , wherein the full-bridge transistor circuit unit comprises:
 a first transistor comprising a drain electrode having DC power applied thereto and a source electrode connected to one terminal of the transmission coil unit;   a second transistor comprising a drain electrode connected to the source electrode of the first transistor and a source electrode connected to a ground;   a third transistor comprising a drain electrode having the DC power applied thereto and a source electrode connected to an opposite terminal of the transmission coil unit; and   a fourth transistor comprising a drain electrode connected to the source electrode of the third transistor and a source electrode connected to the ground.   
     
     
       7. The wireless power transmitting apparatus of  claim 6 , wherein, in the half-bridge operating mode, the transmit power controller turns off the third transistor, turns on the fourth transistor, turns on the first transistor, turns off the second transistor during one half period, and turns off the first transistor and turns on the second transistor during a remaining half period. 
     
     
       8. The wireless power transmitting apparatus of  claim 6 , wherein, in the full-bridge operating mode, the transmit power controller turns on the first and fourth transistors and turns off the second and third transistors during one half period, and turns off the first and fourth transistors and turns on the second and third transistors during a remaining half period. 
     
     
       9. The wireless power transmitting apparatus of  claim 1 , wherein the AC power is a rectangular-waveform power. 
     
     
       10. A method of controlling a wireless power transmitter, the method comprising:
 providing a DC power to an AC power generator;   generating, via the AC power generator, an AC power signal having a predetermined frequency to transmit wireless power;   detecting a variation of consumption of the wireless power;   determining state information of a wireless power receiver based on the variation;   in response to the determined state information indicating the variation is less than a reference value, transmitting, by the AC power generator, the wireless power to have a first waveform; and   in response to the determined state information indicating the variation is equal to or greater than the reference value, transmitting, by the AC power generator, the wireless power to have a second waveform different from the first waveform,   wherein the generating the AC power comprises:   converting, via a DC-DC converter included in the AC power generator, a first DC power into a second DC power determined based on a control signal; and   converting, via a DC-AC converter included in the AC power generator, the second DC power into the wireless power, and   wherein the detecting the variation of the consumption of the wireless power comprises detecting the variation based on a level of an output current of the DC-DC converter and based on an adjustment of a switch and a resistor included in the wireless power receiver.   
     
     
       11. The method of claim 10, wherein the AC power generator includes a full bridge transistor circuit for operating in a full bridge mode or a half bridge mode. 
     
     
       12. The method of claim 11, wherein the AC power generator operates in the half bridge mode for transmitting the first waveform. 
     
     
       13. The method of claim 12, wherein the AC power generator operates in the full bridge mode for transmitting the second waveform. 
     
     
       14. The method of claim 11, wherein the full bridge transistor circuit includes a first half bridge circuit and a second half bridge circuit. 
     
     
       15. The method of claim 14, wherein the AC power generator includes a controller operating the first half bridge circuit and stopping operation of the second half bridge circuit in the half bridge mode. 
     
     
       16. The method of claim 15, wherein the controller operates the first half bridge circuit and the second half bridge circuit in the full bridge mode. 
     
     
       17. The method of claim 11, wherein the detecting the variation of consumption of the wireless power comprises detecting a power consumption of the wireless power based on the switch being opened or closed and in series with the resistor, and
 wherein the power consumption is increased when the switch is closed and decreased when the switch is opened.   
     
     
       18. The method of claim 11, wherein the state information of the wireless power receiver includes a change of a charge quantity of the wireless power. 
     
     
       19. The method of claim 11, wherein the state information of the wireless power receiver includes a maximum power of the wireless power transmitter and an available power of the wireless power transmitter. 
     
     
       20. The method of claim 11, wherein the AC power has the first waveform or the second waveform different than the first waveform based on the state information of the wireless power receiver. 
     
     
       21. A wireless power transmitter wireless transmitting power to a wireless power receiver, the wireless power transmitter comprising:
 an AC power generator configured to generate an AC power signal having a predetermined frequency to transmit wireless power;   a detector configured to detect a variation of consumption of the wireless power; and   a controller configured to:   determine state information of the wireless power receiver based on the detected variation of the consumption of the transmitted power; and   in response to the determined state information indicating the variation is less than a reference value, control a transistor circuit of the AC power generator to transmit the wireless power to have a first waveform; and   in response to the determined state information indicating the variation is equal to or greater than the reference value, control the transistor circuit of the AC power generator to transmit the wireless power to have a second waveform different from the first waveform,   wherein the AC power generator comprises:   a DC-DC converter configured to convert a first DC power into a second DC power determined based on a control signal; and   a DC-AC converter configured to convert the second DC power into the wireless power, and   wherein the detector detects the variation of consumption of the wireless power based on a level of an output current of the DC-DC converter and based on an adjustment of a switch and a resistor included in the wireless power receiver.   
     
     
       22. The wireless power transmitter of claim 21, wherein the AC power generator includes a full bridge transistor circuit for operating in a full bridge mode or a half bridge mode. 
     
     
       23. The wireless power transmitter of claim 22, wherein the AC power generator operates in the half bridge mode for transmitting the first waveform. 
     
     
       24. The wireless power transmitter of claim 23, wherein the AC power generator operates in the full bridge mode for transmitting the second waveform. 
     
     
       25. The wireless power transmitter of claim 22, wherein the full bridge transistor circuit includes a first half bridge circuit and a second half bridge circuit. 
     
     
       26. The wireless power transmitter of claim 25, wherein the controller operates the first half bridge circuit and stops operation of the second half bridge circuit in the half bridge mode. 
     
     
       27. The wireless power transmitter of claim 26, wherein the controller operates the first half bridge circuit and the second half bridge circuit in the full bridge mode. 
     
     
       28. The wireless power transmitter of claim 22, wherein the controller detects the variation of consumption of the wireless power by detecting a power consumption of the wireless power based on the switch being opened or closed and in series with the resistor, and
 wherein the power consumption is increased when the switch is closed and decreased when the switch is opened.   
     
     
       29. The wireless power transmitter of claim 22, wherein the state information of the wireless power receiver includes a change of a charge quantity of the wireless power. 
     
     
       30. The wireless power transmitter of claim 22, wherein the state information of the wireless power receiver includes a maximum power of the wireless power transmitter and an available power of the wireless power transmitter. 
     
     
       31. The wireless power transmitter of claim 22, wherein the AC power has the first waveform or the second waveform different than the first waveform based on the state information of the wireless power receiver.