Non-resonant and quasi-resonant system for wireless power transmission to multiple receivers

• US 9,088,307 B2
• Filed: 12/19/2011
• Issued: 07/21/2015
• Est. Priority Date: 12/29/2010
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Lisi, Gianpaolo, Socci, Gerard G., Djabbari, Ali, Mahmodieh, Kosha
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US13/329,924
• Publication Number:
  US 20120169136A1
• Time in Patent Office: 1,310 Days
• Field of Search: 307/104
• US Class Current: 1/1
• 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: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A wireless power transfer system includes: a non-resonant transmitter, or a transmitter with a resonant circuit; and a non-resonant receiver, or a receiver with a resonant circuit. In some implementations, a transmitter with a resonant circuit is operated away from its resonance frequency. In some implementations, a receiver with a resonant circuit is operated away from the transmitter resonance frequency and/or the transmitter operating frequency. In some implementations, the selection of receiver resonance frequency is based on receiver power requirements. Thus, wireless power transfer may be accomplished by operating away from resonance in a quasi-resonant or non-resonant mode, and further may be accomplished using a non-resonant transmitter and/or a non-resonant receiver. Effective power transfer may also be achieved between a transmitter and multiple receivers. A combination of resonant and non-resonant transmitter and receiver(s) may be used for power transfer.

Claims

1. A wireless power transfer system suitable for wirelessly supplying power from an alternating current (AC) power supply to multiple power receivers, comprising:

a power transmitter including a resonator circuit with a transmitter coil, and characterized by a resonance frequency, a quasi-resonant frequency band on either side of the resonance frequency, and upper and lower non-resonant frequency bands above and below the quasi-resonant frequency band, where the non-resonant frequency band is characterized by a coil voltage substantially equal to the Power supply voltage;

the transmitter circuit configured to transmit power from the power supply through the transmitter coil at a transmitter frequency within the non-resonant frequency band; and

multiple power receivers, each including a receiver circuit with a receiver coil, and configured to receive power through the receiver coil transmitted by the transmitter at the transmitter frequency;

wherein power is transferred to the multiple receivers substantially simultaneously.

2. The wireless power transfer system of claim 1, wherein the receiver includes a resonant receiver circuit, including the receiver coil, with a resonance frequency that corresponds to the transmitter frequency.

3. The wireless power transfer system of claim 1, wherein the AC power supply is configured to receive an input high voltage AC power, and includes an AC-DC converter stage for converting the high voltage AC power to high voltage direct current (DC) power, and a DC-AC converter stage for converting the DC power to AC power for input to the transmitter coil.

4. The wireless power transfer system of claim 1, further comprising a communications link between the transmitter and receiver.

5. The wireless power transfer system of claim 1, the receiver included in an electronic device, the receiver configured to provide transferred power to circuits in the electronic device, thereby functioning as the power source for the circuits during normal operation.

6. The wireless power transfer system of claim 1, the receiver included in an electronic device, the receiver configured to provide transferred power to a battery in the electronic device, thereby charging the battery.

7. The receiver of claim 1, further comprising a communications link between the transmitter and receiver.

8. The receiver of claim 1, the receiver included in an electronic device, the receiver configured to provide transferred power to circuits in the electronic device, thereby functioning as the power source for the circuits during normal operation.

9. The receiver of claim 1, the receiver included in an electronic device, the receiver configured to provide transferred power to a battery in the electronic device, thereby charging the battery.

10. A wireless power transfer transmitter suitable for use in a wireless power transfer system that wirelessly supplies power from an alternating current Power supply to multiple power receivers, the transmitter comprising:

a power transmitter circuit; and

a resonator circuit with a transmitter coil, and characterized by a resonance frequency, a quasi-resonant frequency band on either side of the resonance frequency, and upper and lower non-resonant frequency bands above and below the quasi-resonant frequency band, where the non-resonant frequency band is characterized by a coil voltage substantially equal to the power supply voltage;

the transmitter circuit and the resonator circuit are configured to transmit Power from the power supply through the transmitter coil at a transmitter frequency within the non-resonant frequency band; and

each of the multiple power receivers includes a receiver circuit with a receiver coil, and is configured to receive power through the receiver coil transmitted by the transmitter at the transmitter frequency;

wherein power is transferred to the multiple receivers substantially simultaneously.

11. The wireless power transfer transmitter of claim 10, wherein at least one of the multiple receivers includes a resonant circuit, including the receiver coil, with a resonance frequency that corresponds to the transmitter frequency.

12. The wireless power transfer transmitter of claim 11, further comprising a communication link between the transmitter and the multiple receivers.

13. The wireless power transfer transmitter of claim 11, wherein at least one of the receivers is incorporated with an electronic device, the receiver configured to provide transferred power to a battery in the electronic device, thereby charging the battery.

14. A wireless power transfer receiver suitable for use in a wireless power transfer system that wirelessly supplies power from an alternating current (AC) power supply to multiple power receivers, the system including a power transmitter that includes a transmitter coil, and is configured to transmit power from the power supply through the transmitter coil at a transmitter frequency, the power receiver comprising:

a receiver circuit; and

a receiver coil;

the receiver circuit configured to receive power through the receiver coil transmitted by the transmitter at the transmitter frequency;

wherein the power transmitter comprises a resonant transmitter circuit including the transmitter coil, and wherein

the resonant transmitter circuit is characterized by a resonance frequency, a quasi-resonant frequency band on either side of the resonance frequency, and upper and lower non-resonant frequency bands above and below the quasi-resonant frequency band, and where the non-resonant frequency band is characterized by a coil voltage substantially equal to the power supply voltage, and

the transmitter frequency is within the non-resonant frequency band; and

wherein power is transferred to the receiver substantially simultaneously with power transfer to the other receivers.

15. The receiver of claim 14, wherein the receiver comprises a resonant receiver circuit, including the receiver coil, the resonant receiver circuit characterized by a resonance frequency that corresponds to the transmitter frequency.