DISTRIBUTED CONTROL ADAPTIVE WIRELESS POWER TRANSFER SYSTEM

• US 20170317529A1
• Filed: 07/30/2015
• Published: 11/02/2017
• Est. Priority Date: 05/21/2012
• Status: Abandoned Application

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Smith, Joshua R., Waters, Benjamin
• Application Number:
  US15/503,711
• Publication Number:
  US 20170317529A1
• Time in Patent Office: Days
• 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A wireless power transfer system (100) includes a transmitter (110) configured to transmit power to a receiver (120), for example, through coupled resonators (111,121). The transmitter receives feedback from the receiver, and uses the feedback to control the power transmission, to control a parameter at the receiver, for example, a rectified voltage output by the receiver. The feedback to the transmitter may be provided, for example, by an out-of-band radio system (117, 126) between the transmitter and receiver, by a reflection coefficient at the transmitter (116), and/or by an encoded modulation of power in the receiver, for example, in an impedance matching module (121). The transmitter may control the transmitted power, for example, by controlling a transmitter signal generator voltage (V_SIG), a transmitter gate driver voltage (V_GD), a transmitter amplifier voltage (V_pA), and/or an impedance setting in a transmitter impedance matching module (111).

Claims

1. A wireless power transfer system comprising:

a power transmitter comprising a transmitter controller in signal communication with an amplifier and a transmitter-side impedance matching module, wherein the transmitter-side impedance matching module is configured to transfer power from the amplifier to a transmit resonator; and

a power receiver comprising a receiver controller in signal communication with a receiver-side impedance matching module and a rectifier that outputs a rectified voltage, wherein the receiver-side impedance matching module is configured to transfer power from a receive resonator to the rectifier;

wherein the transmitter controller is configured to receive feedback from the power receiver indicating a state of the power receiver, and to use the received feedback to adjust a parameter of the power transmitter to produce a target rectified voltage at the rectifier.

2. The wireless power transfer system of claim 1, wherein the power receiver does not have a voltage regulator component.

3. The wireless power transfer system of claim 1, wherein the power transmitter further comprises a first radio in signal communication with the transmitter controller and the power receiver further comprises a second radio in signal communication with the receiver controller, wherein the feedback received by the transmitter from the receiver is transmitted from the second radio to the first radio.

4. The wireless power transfer system of claim 3, wherein the feedback received by the transmitter comprises a value indicating a received power level.

5. The wireless power transfer system of claim 3, wherein the feedback received by the transmitter comprises the rectified voltage.

6. The wireless power transfer system of claim 1, wherein the power transmitter further comprises a sensor that detects a reflection signal in the transmitter, wherein the reflection signal indicates a state of the power receiver.

7. The wireless power transfer system of claim 6, wherein the reflection signal comprises a voltage reflection coefficient, S11.

8. The wireless power transfer system of claim 7, wherein the power transmitter further comprises a directional coupler, and the directional coupler detects the voltage reflection coefficient, S11.

9. The wireless power transfer system of claim 1, wherein the receiver controller is configured to monitor a parameter of the power receiver and to modulate the receiver-side impedance matching module to encode the monitored parameter, and further wherein the transmitter controller is configured to monitor a signal generated by the modulation of the receiver-side impedance matching module and to decode the encoded parameter, wherein the encoded parameter comprises the received feedback.

10. The wireless power transfer system of claim 9, wherein the monitored parameter is the rectified voltage.

11. The wireless power transfer system of claim 1, wherein the power transmitter further comprises a sensor to detect a human presence, the sensor in signal communication with the transmitter controller, and wherein the transmitter controller is configured to stop or reduce power transmission in response to a signal from the sensor.

12. The wireless power transfer system of claim 1, wherein the transmitter controller is configured to control the transmitter-side impedance matching module to produce the target rectifier voltage from the rectifier.

13. A wireless power transmitter comprising:

a transmitter controller in signal communication with an amplifier and an impedance matching module, wherein the impedance matching module receives alternating current from the amplifier and energizes a transmit resonator for wireless transmission, wherein the transmitter is configured to transmit radio frequency energy to a receiver having a receive resonator connected to a rectifier configured to produce a rectified voltage;

wherein the transmitter controller is configured to receive feedback from the receiver indicating the rectified voltage, and to use the received feedback to adjust a parameter of the power transmitter to produce a target rectified voltage at the rectifier.

14. The wireless power transmitter of claim 13, wherein the power transmitter receives the feedback through an out-of-band radio.

15. The wireless power transfer system of claim 13, wherein the power transmitter further comprises a sensor that detects a reflection signal in the transmitter, wherein the reflection signal comprises the received feedback.

16. The wireless power transmitter of claim 15, wherein the sensor comprises a directional coupler and the feedback comprises a voltage reflection coefficient, S11.

17. The wireless power transmitter of claim 15, wherein the sensor measures the power consumption of the amplifier.

18. A method of wireless power transmission comprising:

in a transmitter, generating an alternating current with a power amplifier, and using the alternating current to energize a transmit resonator;

in a receiver, receiving power from the transmit resonator with a receive resonator that is coupled to the transmit resonator, and generating a rectified voltage for a load;

providing feedback from the receiver to the transmitter that indicates the rectified voltage; and

using the feedback to adjust the transmitter such that the rectified voltage is maintained at a predetermined value.

19. The method of claim 18, further comprising providing a first impedance matching module between the power amplifier and the transmit resonator, and a second impedance matching module between the rectifier and the receive resonator.

20. The method of claim 18, wherein the transmitter further comprises a first radio, and the receiver further comprises a second radio, wherein the feedback from the receiver to the transmitter is communicated between the first and second radios.

21. The method of claim 18, wherein the transmitter further comprises a directional coupler, and the feedback comprises a reflection signal.