WIRELESS POWER CONTROL

• US 20150207333A1
• Filed: 03/14/2013
• Published: 07/23/2015
• Est. Priority Date: 09/11/2012
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Baarman, David W., Moore, Colin J., Taylor, Joshua B., Norconk, Matthew J., Leppien, Thomas J., Mollema, Scott A., Schwannecke, Joshua K., Moes, Benjamin C., Umenei, A. Esai, Lord, John James, Gruich, Robert D.
• Granted Patent: US 9,912,166 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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 7/00308 Overvoltage protection

Abstract

A remote device in accordance with the present invention includes an adaptive power receiver that receives wireless power from the wireless power supply by induction. The adaptive power receiver may be switched among two or more modes of operation, including, for example, a high-Q mode and a low-Q mode. By controlling the switching between modes, the amount of energy received by the adaptive receiver may be controlled. This control is a form of adaptive resonance control or Q control.

Claims

1. A remote device for receiving wireless power from a wireless power supply, said remote device comprising:

an adaptive power receiver capable of receiving power from the wireless power supply through inductive coupling, said adaptive power receiver configurable to a first mode and configurable to a second mode;

a load for receiving electrical power generated in said adaptive power receiver, wherein in said first mode, said adaptive power receiver is capable of storing energy received from the wireless power supply, wherein said second mode, said adaptive power receiver releases said stored energy to said load; and

a controller operably coupled to the adaptive power receiver, said controller capable of controlling power received from the wireless power supply by selectively configuring the adaptive power receiver between said first mode and said second mode.

2. The remote device as claimed in claim 1 wherein said first mode is a high-Q mode and said second mode is a low-Q mode.

3. The remote device as claimed in claim 2 wherein said controller controls the duration at which said adaptive power receiver is in said high-Q mode in order to maintain the effective Q of the adaptive power receiver above or below a threshold, thereby improving efficiency of power transfer between the wireless power supply and said remote device.

4. The remote device as claimed in claim 1 wherein said adaptive power receiver includes adaptive control circuitry capable of both rectifying received power and switching the adaptive power receiver between said first mode and said second mode.

5. The remote device as claimed in claim 4 wherein said adaptive control circuitry is configurable for semi-synchronous rectification of received power.

6. The remote device as claimed in claim 4 wherein said adaptive power receiver includes a secondary tank circuit, and wherein said adaptive control circuitry includes at least two switches capable of selectively coupling said secondary tank circuit to a common reference;

wherein activating a first switch and a second switch of said at least two switches selectively couples said secondary tank circuit to said common reference through both said first switch and said second switch, thereby configuring said adaptive power receiver in said first mode as a high-Q resonator; and

wherein activating said first switch and leaving said second switch inactive enables semi-synchronous rectification of received power and configures said adaptive power receiver in said second mode as a low-Q resonator.

7. The remote device as claimed in claim 4 wherein said adaptive power receiver is configured from said first mode to said second mode twice per wavelength of said power.

8. The remote device as claimed in claim 4 wherein the controller controls power received by said adaptive power receiver by controlling the duty cycle of said first mode with respect to said second mode for each said wavelength, wherein increasing said duty cycle increases a duration of time over which said adaptive power receiver is in said first mode for each said wavelength, and wherein decreasing said duty cycle decreases said duration of time over which said adaptive power receiver is in said first mode for each said wavelength.

9. The remote device as claimed in claim 8 wherein said duty cycle is controlled to minimize ripple of said power provided to said load and to minimize a bulk capacitance used to buffer said power provided to said load.

10. The remote device as claimed in claim 1 wherein said first mode is resonant and said second mode is highly resonant.

11. The remote device as claimed in claim 1 wherein said power received from the wireless power supply has a power wavelength, and wherein said controller selectively configures the adaptive power receiver from said first mode to said second mode at least once per wavelength of said power.

12. The remote device as claimed in claim 1 further comprising a supplemental receiver capable of receiving power from the wireless power supply through inductive coupling, wherein in said first mode, said adaptive power receiver provides power to said supplemental receiver from said wireless power supply and bypasses providing power directly to said load, and wherein in said second mode, said adaptive power receiver provides power directly to said load.

13. The remote device as claimed in claim 1 wherein said adaptive power receiver has reduced equivalent series resistance in said first mode compared to said second mode.

14. The remote device as claimed in claim 1 wherein said controller controls said adaptive power receiver to increase an amount of power received in response to determining that power received is below a threshold.

15. The remote device as claimed in claim 1 wherein:

upon initialization, said controller determines whether said adaptive power receiver is tightly coupled to the wireless power supply or loosely coupled to the wireless power supply;

based on determining said adaptive power receiver is loosely coupled, said controller begins selectively switching the adaptive power receiver between said first and second modes; and

based on determining said adaptive power receiver is tightly coupled, said controller holds said adaptive power receiver in said second mode.

16. The remote device as claimed in claim 15 wherein said adaptive power receiver becomes loosely coupled at greater distance between the wireless power supply and said remote device, and said adaptive power receiver becomes tightly coupled at closer proximity between the wireless power supply and said remote device.

17. The remote device as claimed in claim 1 wherein said adaptive power receiver includes a single inductor capable of inductively coupling with the wireless power supply.

18. A method for controlling power received from a wireless power supply in a remote device, said method comprising:

receiving power in an adaptive power receiver via inductive coupling with the wireless power supply;

selectively configuring the adaptive power receiver in a first mode in which the adaptive power receiver is capable of storing energy received from the wireless power supply; and

selectively configuring the adaptive power receiver in a second mode in which the adaptive power receiver releases stored energy to a load.

19. The method of claim 18 wherein the first mode is a high-Q mode and the second mode is a low-Q mode.

20. The method of claim 18 further comprising cycling between the first mode and the second mode at a duty cycle to control the amount of power received by the adaptive power receiver.

21. The method of claim 20 wherein the power received from the wireless power supply has a power wavelength, and wherein said cycling occurs at least once per power wavelength.

22. The method of claim 21 further comprising cycling from the first mode to the second mode twice per power wavelength.

23. The method of claim 20 further comprising increasing the duty cycle of said cycling in order to increase an effective Q of the adaptive power receiver.

24. The method of claim 20 further comprising decreasing the duty cycle of said cycling in order to decrease an effective Q of the adaptive power receiver.

25. A wireless power transmitter for transmitting wireless power to a remote device, said wireless power transmitter comprising:

an adaptive power transmitter capable of transmitting wireless power to the remote device, said adaptive power transmitter configurable to a first mode and configurable to a second mode;

wherein in said first mode, said adaptive power transmitter has a first resonant frequency, wherein in said second mode, said adaptive power transmitter has a second, different, resonant frequency; and

a controller operably coupled to the adaptive power receiver, said controller capable of controlling power transmitted by the wireless power supply by selectively configuring the adaptive power transmitter between said first mode and said second mode.

26. The wireless power transmitter of claim 25 wherein said adaptive power transmitter includes an impedance element and a switch, wherein in said first mode said switch is closed and said impedance element is electrically connected to said adaptive power transmitter, wherein in said second mode said switch is open and said impedance element is electrically disconnected from said adaptive power transmitter.

27. The wireless power transmitter of claim 26 wherein said controller is capable of controlling power transmitted to the remote by selectively configuring the adaptive power transmitter between the first mode and the second mode by selectively configuring the adaptive power transmitter from the first mode to the second mode at least once per wavelength of the power transmitted.

28. The wireless power transmitter of claim 26 wherein said controller is capable of controlling power transmitted to the remote by selectively configuring the adaptive power transmitter between the first mode and the second mode by selectively configuring the adaptive power transmitter from the first mode to the second mode at least twice per wavelength of the power transmitted.

29. The wireless power transmitter of claim 26 wherein said controller changes the resonant frequency by changing the duration of time over which the adaptive power transmitter is in the first mode relative to the duration of time over which the adaptive power transmitter is in the second mode.

30. A wireless power transmitter for transmitting wireless power to a remote device, said wireless power transmitter comprising:

an adaptive power transmitter capable of transmitting wireless power to the remote device, said adaptive power transmitter configurable to a first mode and configurable to a second mode;

wherein in said first mode, said adaptive power transmitter has a lower Q factor, wherein in said second mode, said adaptive power transmitter has a higher Q factor; and

a controller operably coupled to said adaptive power receiver, said controller capable of controlling power transmitted by the wireless power supply by selectively configuring said adaptive power transmitter between said first mode and said second mode.

31. The wireless power transmitter of claim 30 wherein said adaptive power transmitter includes a resistor and a switch, wherein in said first mode said switch is closed and said resistor is electrically connected to said adaptive power transmitter, wherein in said second mode said switch is open and said resistor is electrically disconnected from said adaptive power transmitter.

32. The wireless power transmitter of claim 30 wherein said controller is capable of controlling power transmitted to the remote by selectively configuring the adaptive power transmitter between the first mode and the second mode by selectively configuring the adaptive power transmitter from the first mode to the second mode at least once per wavelength of the power transmitted.

33. The wireless power transmitter of claim 30 wherein said controller is capable of controlling power transmitted to the remote by selectively configuring the adaptive power transmitter between the first mode and the second mode by selectively configuring the adaptive power transmitter from the first mode to the second mode at least twice per wavelength of the power transmitted.

34. The wireless power transmitter of claim 30 wherein said controller changes the resonant frequency by changing the duration of time over which the adaptive power transmitter is in the first mode relative to the duration of time over which the adaptive power transmitter is in the second mode.