Adaptive Rectifier And Method Of Operation

• US 20160043562A1
• Filed: 03/13/2015
• Published: 02/11/2016
• Est. Priority Date: 08/08/2014
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Lisi, Gianpaolo, Subramonian, Rajaram, Socci, Gerard, Desai, Nachiket V., Arora, Sakshi, Du, Dingkun
• Granted Patent: US 9,831,684 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 wireless power transfer system includes a wireless power receiver having a rectifier. The rectifier includes switches. The wireless power receiver is operable to control the switches for ensuring a complex impedance at the input of the rectifier.

Claims

1. A wireless power transfer system, comprising:

a wireless power receiver having a rectifier, the rectifier including switches, and the wireless power receiver operable to control the switches for ensuring complex impedance at an input of the rectifier.

2. The wireless power transfer system of claim 1, wherein the wireless power receiver is operable to control the switches for ensuring complex impedance with variable phase into the rectifier.

3. The wireless power transfer system of claim 2, wherein the wireless power receiver is operable to control an output pulse width for control of a first parameter and to control the phase of the output pulse to adjust a second parameter.

4. The wireless power transfer system of claim 3, wherein the first parameter is output current to a load and the second parameter is efficiency of the wireless power receiver.

5. The wireless power transfer system of claim 3, wherein the first parameter is voltage to a load and the second parameter is efficiency of the wireless power receiver.

6. The wireless power transfer system of claim 2, wherein the wireless power receiver is operable to control the phase of the complex impedance to the rectifier so that the resistance of the input to the rectifier is negative.

7. The wireless power transfer system of claim 6, wherein the wireless power receiver is operable to transfer power to a wireless power transmitter when the resistance of the input to the rectifier is negative.

8. The wireless power transfer system of claim 1, further comprising:

a wireless power transmitter operable to sense current phase changes resulting from reflected impedance of the rectifier in the wireless power receiver;

wherein the wireless power transmitter is operable to control a parameter in the wireless power transmitter in response to the reflected impedance of the rectifier in the wireless power receiver.

9. The wireless power transfer system of claim 1, the wireless power receiver operable to encode information in the variable impedance of the rectifier.

10. The wireless power transfer system of claim 9, further comprising:

a wireless power transmitter operable to sense parameter changes resulting from reflected variable impedance of the rectifier in the wireless power receiver;

wherein the wireless power transmitter operable to decode information encoded in the parameter changes.

11. The wireless power transfer system of claim 1, further comprising:

circuitry operable to prevent the magnitude of the output voltage of the rectifier from exceeding a maximum value.

12. A resonant power conversion circuit, comprising:

a resonant circuit including an inductor, a capacitor, and a rectifier; and

a controller operable to control the impedance of the rectifier to dynamically tune the resonant circuit to a specific frequency.

13. The resonant power conversion circuit of claim 12, wherein the resonant circuit is part of a wireless power transmitter.

14. A method of controlling a wireless power transfer system, the method comprising:

controlling, by control circuitry in a wireless power receiver, switches in a rectifier, to ensure a complex impedance an the input of the rectifier.

15. The method of claim 14, further comprising:

controlling, by the control circuitry in the wireless power receiver, the switches in the rectifier, to control two different operating parameters of the wireless receiver.

16. The method of claim 14, further comprising:

controlling, by the control circuitry in the wireless power receiver, the switches in the rectifier, to control the phase of the impedance to the rectifier so that the resistance of the input to the rectifier is negative.

17. The method of claim 16, further comprising:

wirelessly transferring, by the wireless power receiver, power to a wireless power transmitter.

18. The method of claim 14, further comprising:

encoding, by the wireless power receiver, information in the variable impedance of the rectifier.

19. The method of claim 18, further comprising:

sensing, by a wireless power transmitter, impedance changes reflected from the wireless power receiver; and

decoding, by the wireless power transmitter, information encoded in the reflected impedance changes.

20. The method of claim 14, further comprising:

controlling, by the control circuitry in the wireless power receiver, the switches in the rectifier, to discharge a voltage at the output of the rectifier.