WIRELESS POWER TRANSMISSION APPARATUS AND TRANSMISSION METHOD THEREOF

• US 20120038220A1
• Filed: 08/11/2011
• Published: 02/16/2012
• Est. Priority Date: 08/13/2010
• Status: Active Grant

• Current Assignee: Wit Co., Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kim, Jeong Hoon, Lee, Kwang Du, Park, Chul Gyun, Yoon, Jung Ho, Kim, Eung Ju, Hwang, Sang Hoon
• Granted Patent: US 9,509,374 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Disclosed herein are a wireless power transmission apparatus and a transmission method thereof. The wireless power transmission apparatus is configured to include a wireless power transmitter generating a wireless power signal to be wireless transmitted, wirelessly transmitting the generated wireless power signal by a magnetic resonance manner, receiving a reflection wireless power signal to determine whether or not a load apparatus is presented, and supplying power to the load apparatus; and a wireless power receiver connected to the load apparatus and receiving the transmitted wireless power signal by the magnetic resonance manner and supplying it to the connected load apparatus and reflecting the remaining wireless power signal to the wireless power transmitter, whereby a transmission apparatus can recognize a receiving environment and resonance characteristics are improved, without a separate communication device or a system.

Claims

1. A wireless power transmission apparatus, comprising:

a wireless power transmitter receiving power input from the outside and generating a wireless power signal to be wirelessly transmitted, wireless transmitting the generated wireless power signal by a magnetic resonance manner, receiving a reflection wireless power signal to determine whether or not a load apparatus is presented, and if it is determined that the load apparatus is presented, wirelessly transmitting the wireless power signal by using an optimal impedance and a resonance frequency corresponding to the load apparatus in order to supply power to the load apparatus; and

a wireless power receiver connected to the load apparatus and receiving the wireless power signal transmitted from the wireless power transmitter by the magnetic resonance manner and supplying it to the connected load apparatus and reflecting the remaining wireless power signal, that is not consumed, to the wireless power transmitter.

2. The wireless power transmission apparatus as set forth in claim 1, wherein the wireless power transmitter includes:

a frequency oscillator receiving power input from the outside and generating a wireless power signal to be transmitted;

a power amplifier amplifying and outputting the wireless power signal generated from the frequency oscillator;

a first resonance antenna including a variable capacitor circuit and a variable inductor circuit, transmitting the wireless power signal by the magnetic resonance manner by using the optimal impedance and the resonance frequency searched by varying the inductance and capacitance of the variable capacitor circuit and the variable inductor circuit, and receiving and outputting the wireless power signal reflected from the wireless power receiver;

an impedance matching device positioned between the power amplifier and the first resonance antenna to provide the impedance matching between the power amplifier and the first resonance antenna;

a directional power coupler positioned between the power amplifier and the impedance matching device or between the impedance matching device and the first resonance antenna and having directivity to output the wireless power signal input through a first port from the power amplifier or the impedance matching device to the first resonance antenna through a second port and to output the reflection wireless power signal input through the second port from the first resonance antenna through a third port;

an output power detector detecting and outputting the output power of the wireless power signal output from the second port of the directional power coupler;

a reflection power detector detecting and outputting the reflection power of the reflection wireless power signal output from the third port of the directional power coupler; and

a transmitting controller calculating the ratio of the reflection power to the output power, determining whether or not the load apparatus is presented according to the calculated output-reflection power ratio, and controlling the first resonance antenna so as to transmit the wireless power signal by using the optimal impedance and the resonance frequency corresponding to the load apparatus.

3. The wireless power transmission apparatus as set forth in claim 2, wherein the impedance matching device includes:

a transformation module including a primary winding and a secondary winding;

a plurality of first switches mounted at the primary winding;

a plurality of second switches mounted at the secondary winding; and

a first switch controller connected to the plurality of first and second switches and controlling the plurality of first and second switches to vary the winding ratio of the primary winding to the secondary winding in order to control the real components of the impedance.

4. The wireless power transmission apparatus as set forth in claim 3, wherein the transmitting controller searches minimum turning points of the reflection wireless power signal received in the reflection power detector while changing the real components of the impedance of the impedance matching device to set the real components of impedance corresponding to the searched minimum turning points as the real components of the optimal impedance of the impedance matching device.

5. The wireless power transmission apparatus as set forth in claim 2, wherein the first resonance antenna includes:

a variable capacitor circuit varying capacitance by connecting a plurality of capacitors in parallel and connecting a plurality of third switches to each of the plurality of capacitors in series,

a variable inductor circuit varying inductance by connecting a plurality of inductors in series and connecting a plurality of fourth switches to each of the plurality of inductors in parallel; and

a second switch controller connected to the plurality of third and fourth switches and controlling the plurality of third and fourth switches to vary the capacitance and the inductance in order to search the imaginary components of the resonance frequency and the optimal impedance,

the variable capacitor circuit and the variable inductor circuit being connected in series or in parallel.

6. The wireless power transmission apparatus as set forth in claim 5, wherein the transmitting controller searches a minimum turning point of the reflection wireless power signal received in the reflection power detector while changing the imaginary components of the frequency and the impedance of the first resonance antenna, respectively, to set the imaginary components of the frequency and the impedance corresponding to each of the searched minimum turning points as the imaginary components of the resonance frequency and the optimal impedance of the first resonance antenna.

7. The wireless power transmission apparatus as set forth in claim 2, wherein the wireless power transmitter further includes a power pass switch providing a bypass path to connect between the frequency oscillator and the power amplifier or to connect the frequency oscillator to the impedance matching device or the directional power coupler according to whether or not the load apparatus is presented.

8. The wireless power transmission apparatus as set forth in claim 1, wherein the wireless power receiver includes:

a second resonance antenna including the variable capacitor circuit and the variable inductor circuit, receiving the wireless power signals transmitted from the wireless power transmitter by the magnetic resonance manner by using the optimal impedance and the resonance frequency searched by varying the inductance and the capacitance of the variable capacitor circuit and the inductor circuit and reflecting the remaining wireless power signal to the wireless power transmitter;

a rectifier rectifying the wireless power signal received by the second resonance antenna;

a power signal converter connected to the load apparatus and converting the wireless power signal rectified by the rectifier into the power signal according to a power supplying manner and supplying the converted power signal to the load apparatus; and

a receiving controller performing a control to receive the wireless power signal in the second resonance antenna by the magnetic resonance manner and supply power to the load apparatus and to reflect the remaining wireless power signal to the wireless power transmitter.

9. The wireless power transmission apparatus as set forth in claim 8, wherein the second resonance antenna includes:

a variable capacitor circuit varying capacitance by connecting a plurality of capacitors in parallel and connecting a plurality of fifth switches to each of the plurality of capacitors in series,

a variable inductor circuit varying inductance by connecting a plurality of inductors in series and connecting a plurality of sixth switches to each of the plurality of inductors in parallel; and

a third switch controller connected to the plurality of fifth and sixth switches and controlling the plurality of fifth and sixth switches to vary the capacitance and the inductance in order to search the imaginary components of the resonance frequency and the optimal impedance,

the variable capacitor circuit and the variable inductor circuit being connected in series or in parallel.

10. The wireless power transmission apparatus as set forth in claim 8, wherein the wireless power receiver further includes a switch positioned between the second resonance antenna and the rectifier to interrupt the wireless power transmission received in the second resonance antenna, and

the receiving controller controls the switch in the case where the connection of the load apparatus is disconnected to interrupt the power transmission received in the second resonance antenna.

11. A wireless power transmitter, comprising:

a frequency oscillator receiving power input from the outside and generating a wireless power signal to be transmitted;

a power amplifier amplifying and outputting the wireless power signal generated from the frequency oscillator;

a first resonance antenna including a variable capacitor circuit and a variable inductor circuit, transmitting the wireless power signal by the magnetic resonance manner by using the optimal impedance and the resonance frequency set by varying the inductance and capacitance of the variable capacitor circuit and the variable inductor circuit, and receiving and outputting the wireless power signal reflected from the wireless power receiver;

an impedance matching device positioned between the power amplifier and the first resonance antenna to provide the impedance matching between the power amplifier and the first resonance antenna;

a directional power coupler positioned between the power amplifier and the impedance matching device or between the impedance matching device and the first resonance antenna and having directivity to output the wireless power signal input through a first port from the power amplifier or the impedance matching device to the first resonance antenna through a second port and output the reflection wireless power signal input through the second port from the first resonance antenna through a third port;

an output power detector detecting and outputting the output power of the wireless power signal output from the second port of the directional power coupler;

a reflection power detector detecting and outputting the reflection power of the reflection wireless power signal output from the third port of the directional power coupler; and

a transmitting controller calculating the ratio of the reflection power to the output power, determining whether or not the load apparatus is presented according to the calculated output-reflection power ratio, and controlling the first resonance antenna so as to transmit the wireless power signal by using the optimal impedance and the resonance frequency corresponding to the load apparatus.

12. The wireless power transmitter as set forth in claim 11, wherein the impedance matching device includes:

a transformation module including a primary winding and a secondary winding;

a plurality of first switches mounted at the primary winding;

a plurality of second switches mounted at the secondary winding; and

a first switch controller connected to the plurality of first and second switches and controlling the plurality of first and second switches to vary the winding ratio of the primary winding to the second winding in order to control the real components of the impedance.

13. The wireless power transmitter as set forth in claim 12, wherein the transmitting controller searches minimum turning points of the reflection wireless power signal received in the reflection power detector while changing the real components of the impedance of the impedance matching device, to set the real components of impedance corresponding to the searched minimum turning points as the real components of the optimal impedance of the impedance matching device.

14. The wireless power transmitter as set forth in claim 11, wherein the first resonance antenna includes:

a variable capacitor circuit varying capacitance by connecting a plurality of capacitors in parallel and connecting a plurality of third switches to each of the plurality of capacitors in series;

a variable inductor circuit varying inductance by connecting a plurality of inductors in series and connecting a plurality of fourth switches to each of the plurality of inductors in parallel; and

a second switch controller connected to the plurality of third and fourth switches and controlling the plurality of third and fourth switches to vary the capacitance and the inductance in order to search the imaginary components of the resonance frequency and the optimal impedance,

the variable capacitor circuit and the variable inductor circuit being connected in series or in parallel.

15. The wireless power transmitter as set forth in claim 14, wherein the transmitting controller searches each of minimum turning points of the reflection wireless power signal received in the reflection power detector while changing the imaginary components of the frequency and the impedance of the first resonance antenna, respectively, to set the imaginary components of the frequency and the impedance corresponding to each of the searched minimum turning points as the imaginary components of the resonance frequency and the optimal impedance of the first resonance antenna.

16. The wireless power transmitter as set forth in claim 11, further comprising a power pass switch providing a bypass path to connect between the frequency oscillator and the power amplifier or to connect the frequency oscillator to the impedance matching device or the directional power coupler according to whether or not the load apparatus is presented.

17. The wireless power transmitter as set forth in claim 11, wherein the directional power coupler is a circulator.

18. A wireless power receiver connected to be a load apparatus, comprising:

a second resonance antenna including a variable capacitor circuit and a variable inductor circuit, receiving wireless power signals transmitted from a wireless power transmitter by a magnetic resonance manner by using optimal impedance and resonance frequency searched by varying the inductance and the capacitance of the variable capacitor circuit and the variable inductor circuit and reflecting the remaining wireless power signal to the wireless power transmitter;

a rectifier rectifying the wireless power signal received by a second resonance antenna;

a power signal converter connected to a load apparatus and converting the wireless power signal rectified by the rectifier into a power signal according to a power supplying manner and supplying the converted power signal to the load apparatus; and

a receiving controller performing a control to receive the wireless power signal in the second resonance antenna by the magnetic resonance manner and supply power to the load apparatus and to reflect the remaining wireless power signal to the wireless power transmitter.

19. The wireless power receiver as set forth in claim 18, further comprising a switch positioned between the second resonance antenna and the rectifier to interrupt the wireless power transmission received in the second resonance antenna, wherein the receiving controller controls the switch in the case where the connection of the load apparatus is disconnected to interrupt the power transmission received in the second resonance antenna.

20. The wireless power receiver as set forth in claim 18, wherein the second resonance antenna includes:

a variable capacitor circuit varying capacitance by connecting a plurality of capacitors in parallel and connecting a plurality of fifth switches to each of the plurality of capacitors in series;

a variable inductor circuit varying inductance by connecting a plurality of inductors in series and connecting a plurality of sixth switches to each of the plurality of inductors in parallel; and

a third switch controller connected to the plurality of fifth and sixth switches and controlling the plurality of fifth and sixth switches to vary the capacitance and the inductance in order to search the imaginary components of the resonance frequency and the optimal impedance,

the variable capacitor circuit and the variable inductor circuit being connected in series or in parallel.

21. The wireless power receiver as set forth in claim 18, wherein the power signal converter includes:

an AC converter converting the rectified wireless power signal into an alternating signal; and

an AC-DC converter converting the rectified wireless power signal into a DC signal.

22. A wireless power transmission method, comprising:

(A) detecting a reflected wireless power signal by transmitting a wireless power signal to a wireless power receiver by a wireless power transmitter according to a magnetic resonance manner to confirm whether or not a load apparatus is presented; and

(B) if it is determined that the load apparatus connected to the wireless power receiver is presented by the wireless power transmitter, searching a resonance frequency and an optimal impedance performing maximum power transmission and transmitting the wireless power signal by using the searched resonance frequency and optimal impedance.

23. The wireless power transmission method as set forth in claim 22, wherein step (A) includes:

(A-1) transmitting the wireless power signal to the wireless power receiver by the wireless power transmitter according to a magnetic resonance manner;

(A-2) receiving the transmitted wireless power signal by the wireless power receiver and reflecting the remaining wireless power signal; and

(A-3) receiving the reflection wireless power signal by the wireless power transmitter to detect the reflection power strength and then, confirming whether or not the load apparatus is connected to the wireless power receiver according to the reflection power strength.

24. The wireless power transmission method as set forth in claim 22, wherein step (B) includes:

(B-1) if it is determined that the load apparatus is connected to the wireless power receiver by the wireless power transmitter, searching minimum turning points of the reflection wireless power signal while varying a frequency and searching the minimum turning points of the reflection wireless power signal while varying impedance;

(B-2) setting a frequency and impedance corresponding to each of the minimum turning points searched by the wireless power transmitter as a resonance frequency and an optimal impedance performing maximum power transmission; and

(B-3) transmitting the wireless power signal in a state where the wireless power signal is matched to the optimal impedance in the resonance frequency.

25. A wireless power transmission method, comprising:

(A) transmitting the wireless power signal to the wireless power receiver by a wireless power transmitter according to a magnetic resonance manner;

(B) receiving the reflection wireless power signal reflected from the wireless power receiver by the wireless power transmitter to detect power strength and confirming whether or not a load apparatus is presented; and

(C) if it is determined that the load apparatus is presented by the wireless power transmitter, searching an optimal impedance and a resonance frequency performing maximum power transmission and transmitting the wireless power signal by using the searched optimal impedance and resonance frequency.

26. The wireless power transmission method as set forth in claim 25, wherein step (C) includes:

(C-1) if it is determined that the load apparatus is connected by the wireless power transmitter, searching minimum turning points of the reflection wireless power signal while varying a frequency and searching the minimum turning points of the reflection wireless power signal while varying impedance; and

(C-2) setting a frequency and impedance corresponding to each of the minimum turning points searched by the wireless power transmitter as a resonance frequency and an optimal impedance performing maximum power transmission, and transmitting the wireless power signal in a state where the wireless power signal is matched to the optimal impedance in the resonance frequency.

27. The wireless power transmission method as set forth in claim 26, wherein step (C-1) includes:

searching the minimum turning points of the reflection wireless power signal while varying the real component of the impedance; and

searching the minimum turning points of the reflection wireless power signal while varying the imaginary components of the impedance.

28. A wireless power receiving method, comprising:

(A) supplying wireless power remaining after a wireless power receiver receives and reflects a wireless power signal transmitted from a wireless power transmitter to a load apparatus connected to the wireless power receiver; and

(B) when the load apparatus connected to the wireless power receiver is disconnected, stopping receiving the wireless power signal transmitted from the wireless power transmitter.