METHOD AND APPARATUS FOR WIRELESS POWER TRANSMISSION

• US 20140084688A1
• Filed: 09/16/2013
• Published: 03/27/2014
• Est. Priority Date: 09/21/2012
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Tzanidis, Ioannis, Rajagopal, Sridhar, Azad, Umar
• Application Number:
  US14/028,254
• Publication Number:
  US 20140084688A1
• Time in Patent Office: Days
• US Class Current: 307/42
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• 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

A method for wireless power transmission includes establishing respective wireless communication link between a coordinating transmitter and each receiver. The method further includes measuring respective mutual impedance between a coordinating transmitter and each receiver by applying a voltage to the coordinating transmitter and configuring each receiver to measure an induced current in response to the applied voltage. The method calculates respective matching impedance for the coordinating transmitter and each receiver based on corresponding mutual impedance. The method transmits the respective matching impedance to each receiver to enable each receiver to adjust to have the respective matching impedance. The method adjusts the coordinating transmitter to have the respective matching impedance.

Claims

1. A method for wireless power transmission, the method comprising:

establishing respective wireless communication link between a coordinating transmitter and each receiver;

measuring respective mutual impedance between a coordinating transmitter and each receiver by applying a voltage to the coordinating transmitter and configuring each receiver to measure an induced current in response to the applied voltage;

calculating respective matching impedance for the coordinating transmitter and each receiver based on corresponding mutual impedance;

transmitting the respective matching impedance to each receiver to enable each receiver to adjust to have the respective matching impedance; and

adjusting the coordinating transmitter to have the respective matching impedance.

2. The method of claim 1, the method further comprising:

configuring each receiver to apply a voltage to each receiver to measure respective self-impedance of each receiver.

3. The method of claim 1, wherein during measuring features on each self-impedance each receiver sequentially is configured to apply a voltage to its inductive resonator and measure a corresponding current, and the other devices are configured to disconnect their loads from their inductive resonators.

4. The method of claim 3, wherein the coordinating transmitter is configured to transmit signals for each device either to apply a voltage to its inductive resonator or to disconnect its load from its inductive resonator.

5. The method of claim 4, wherein the signals include sequence digits for each receiver or time slots assigned to each device for applying a voltage to its circuit or disconnecting its load from its inductive resonator.

6. The method of claim 1, wherein during measuring each mutual impedance the coordinating transmitter is configured to apply a voltage to its inductive resonator and each receiver is configured to sequentially measure a corresponding current while other devices disconnect their loads from their inductive resonators.

7. The method of claim 6, wherein the coordinating transmitter is configured to transmit signals for each receiver either to apply a voltage to its inductive resonator or to disconnect its load from its inductive resonator.

8. The method of claim 7, wherein the signals include sequence digits for each receiver or time slots assigned to each device for applying a voltage to its inductive resonator or disconnecting its load from its inductive resonator.

9. The method of claim 1, the method further comprising:

detecting at least one trigger event to initiate an impedance matching operation.

10. The method of claim 9, wherein the at least one trigger event includes that a new receiver enters the wireless power transfer network.

11. The method of claim 10, wherein the at least at least one trigger event includes that an amount of a change of a Voltage Standing Wave Ratio (VSWR) at the coordinating transmitter is greater than a threshold.

12. The method of claim 1, wherein the matching impedances are calculated to accomplish a required power transfer efficiency.

13. The method of claim 1, wherein a ratio of source resistance to source inductive resonator loss resistance of R_s/R_L1 and a ratio of load resistance to load inductive resonator loss resistance of R_n/R_Ln follows the following equation:

14. The method of claim 13, wherein an optimal power transfer efficiency is a sum of weighted individual power transferred efficiencies of each receiver.

15. The method of claim 1, wherein at least one receiver is a repeater located between the transmitter and the other receiver(s).

16. A coordinating transmitter for wireless power transmission, the coordinating transmitter comprising a processing circuitry configured to:

establish respective wireless communication link between the transmitter and each receiver;

measure respective mutual impedance between a coordinating transmitter and each receiver by applying a voltage to the coordinating transmitter and configuring each receiver to measure an induced current in response to the applied voltage;

calculate respective matching impedance for the coordinating transmitter and each receiver based on corresponding mutual impedance;

transmit the respective matching impedance to each receiver to enable each receiver to adjust to have the respective matching impedance; and

adjust the coordinating transmitter to have the respective matching impedance.

17. The coordinating transmitter of claim 16, wherein the processing circuitry configures each receiver to apply a voltage to each receiver to measure respective self-impedance of each receiver.

18. The coordinating transmitter of claim 16, wherein during measuring each internal-impedance each receiver is configured to sequentially apply a voltage to its circuit and measure currents corresponding to the voltage, and the other devices are configured to disconnect their loads from their inductive resonators.

19. The coordinating transmitter of claim 18, wherein the transmitter is configured to transmit signals for each device either to apply a voltage to its circuit or to disconnect its load from its inductive resonator.

20. The coordinating transmitter of claim 19, wherein the signals include sequence digits for each receiver or time slots assigned to each device for applying a voltage to their circuits or disconnecting their circuits.

21. The coordinating transmitter of claim 16, wherein during measuring respective mutual impedance the transmitter applies a voltage to its circuit and each receiver is configured to sequentially measure a corresponding current, and other devices are configured to disconnect their loads from their inductive resonators.

22. The coordinating transmitter of claim 21, wherein the transmitter is configured to transmit signals for each device either to apply a voltage to its circuit or to disconnect the circuit.

23. The coordinating transmitter of claim 22, wherein the signals include sequence digits for each receiver or time slots assigned to each device for applying a voltage to its circuit or disconnecting the circuit.

24. The coordinating transmitter of claim 16, the method further comprising:

detecting at least one trigger event to initiate matching impedances of the transmitter and each receiver.

25. The coordinating transmitter of claim 24, wherein the at least one trigger event includes that a new receiver enters the wireless power transfer network.

26. The coordinating transmitter of claim 25, wherein the at least at least one trigger event includes that an amount of a change of a Voltage Standing Wave Ratio (VSWR) at the transmitter is greater than a threshold.

27. The coordinating transmitter of claim 16, wherein each impedance for the transmitter and each receiver are calculated to accomplish an optimal resonant coupling efficiency.

28. The coordinating transmitter of claim 16, wherein a ratio of source resistance to source inductive resonator resistance of R_s/R_L1 and a ratio of load resistance to load inductive resonator resistance of R_n/R_Ln follow the following equation:

29. The coordinating transmitter of claim 16, wherein optimal resonant coupling efficiency is a sum of weighted individual resonant coupling efficiencies of each receiver.

30. The coordinating transmitter of claim 16, wherein at least one repeater is located between the transmitter and each receiver.

31. A receiver for wireless power transmission, the receiver comprising a processing circuitry configured to:

establish a wireless communication link with a coordinating transmitter;

obtain information relating to a mutual impedance by measuring an induced current when the coordinating transmitter applies a voltage to its circuit;

transmit information relating to the mutual impedance to the coordinate transmitter;

receive a matching impedance from the coordinating transmitter; and

adjust the receiver to have the matching impedance.

32. The receiver of claim 31, wherein the processing circuitry is configured to apply a voltage to the receiver to measure a self-impedance.

33. The receiver of claim 31, wherein the transmitter is configured to transmit a signal for the receiver either to apply a voltage to its circuit or to disconnect its load from its inductive resonator.

34. The receiver of claim 31, wherein the signal include sequence digits or time slots assigned to the receiver, for applying a voltage to its circuit or disconnecting its load from its inductive resonator.

35. The receiver of claim 31, wherein during measuring the mutual impedance the transmitter is configured to apply a voltage to its circuit and the receiver is configured to measure a corresponding current.

36. The receiver of claim 31, wherein the transmitter is configured to transmit signals for the receiver either to apply a voltage to its circuit or to disconnect its load from its inductive resonator.

37. The receiver of claim 31, wherein the signals include sequence digits for the receiver or time slots assigned to the receiver for applying a voltage to its circuit or disconnecting its load from its inductive resonator.

38. The receiver of claim 31, wherein the controller is configured to detect at least one trigger event to initiate an operation for matching impedances of the transmitter and each receiver.

39. The receiver of claim 38, wherein the at least one trigger event includes that a new receiver enters the wireless power transfer network.

40. The receiver of claim 39, wherein the at least at least one trigger event includes that an amount of a change of a Voltage Standing Wave Ratio (VSWR) at the transmitter is greater than a threshold.

41. The receiver of claim 31, wherein the impedances for the transmitter and the receiver are calculated to accomplish an optimal resonant coupling efficiency.

42. The receiver of claim 31, wherein a ratio of source resistance to source inductive resonator resistance of R_s/R_L1 and a ratio of load resistance to load inductive resonator resistance of R_L/R_L2 follow the following equation:

43. The receiver of claim 31, wherein optimal resonant coupling efficiency is a sum of weighted individual resonant coupling efficiencies of each receiver.

44. The receiver of claim 31, wherein at least one repeater is located between the transmitter and each receiver.

45. A method for wireless power transmission in a wireless power transfer network, the method comprising:

establishing respective wireless communication link between devices including a coordinating transmitter and at least one receiver;

measuring self-impedances of each device by configuring each device to switch to State-1, where the device applies a voltage to its inductive resonator and measure a respective current, and the other device(s) to switch to State-4, where its inductive resonator is open circuited;

measuring mutual impedances of the devices in pairs by switching one device of each pair to State-2, where the device applies a voltage to its inductive resonator, switching the other device of each pair is switched to State-3, where the device measures the current induced to its inductive resonator as a result of the voltage applied to the one device'"'"'s inductive resonator, while a non-paired device(s) in the wireless power transfer network is switched to State-4, where its inductive resonator is open circuited;

configuring the receivers to transmit the respective applied voltage and measured induced current to the coordinating transmitter;

receiving, by the coordinating transmitter, the respective voltage and measured current from each device via the wireless communication link;

calculating respective matching impedance for the coordinating transmitter and each receiver based on corresponding self impedance and mutual impedance;

transmitting the respective matching impedance to each receiver to enable each receiver to adjust to have the respective matching impedance; and

adjusting the coordinating transmitter to have the respective matching impedance.