Wireless power transfer for stationary applications

• US 10,742,071 B2
• Filed: 01/19/2017
• Issued: 08/11/2020
• Est. Priority Date: 01/19/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: von Novak, III, William Henry
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Dominique, Emmanuel
• Application Number:
  US15/410,541
• Publication Number:
  US 20180205263A1
• Time in Patent Office: 1,300 Days
• 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 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• 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 7/35 with light sensitive cells
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

The present disclosure describes aspects of wireless power transfer for stationary applications. In some aspects, a system includes a transmitter and receiver separated by a wireless gap with a membrane. The transmitter has an inverter circuit to invert direct current (DC) power from a DC power source to alternating current (AC) power. The transmitter also has a transmitting circuit that includes a first resonant coil configured to resonate at a frequency of the AC power. The first resonant coil is also configured to wirelessly transmit the AC power across the wireless gap. The receiver has a receiving circuit that includes a second resonant coil configured to resonate based on resonance of the first resonant coil and to receive the wirelessly transmitted AC power. Additionally, the first and second resonant coils are configured as primary and secondary windings, respectively, of a transformer to transform the wirelessly transmitted AC power.

Claims

1. A system for wirelessly transferring and transforming power across a wireless gap that includes a membrane, the system comprising:

a transmitter having an inverter circuit and a transmitting circuit, the inverter circuit configured to invert direct current (DC) power obtained from a DC power source to alternating current (AC) power, the transmitter configured to convert the AC power to pulsing DC power, the transmitting circuit including;

a first resonant coil configured to resonate at a frequency of the pulsing DC power and to wirelessly transmit the pulsing DC power across the membrane of the wireless gap; and

a first tunable capacitor coupled to the first resonant coil, the first tunable capacitor being tunable to adjust a resonant frequency of the first resonant coil for wirelessly transmitting the pulsing DC power; and

a receiver separated from the transmitter by the wireless gap and having a receiving circuit with a second resonant coil, the second resonant coil configured to resonate based on resonance of the first resonant coil and to receive the wirelessly transmitted pulsing DC power, the receiving circuit including;

a second tunable capacitor coupled to the second resonant coil, the second tunable capacitor being tunable to adjust a resonant frequency of the second resonant coil,

the first and second resonant coils being further configured as primary and secondary windings, respectively, of a transformer to transform, across the wireless gap, the wirelessly transmitted pulsing DC power from a first voltage at the first resonant coil to a second voltage at the second resonant coil that is suitable for use by a power recipient.

2. The system as recited in claim 1, wherein the wirelessly transmitted pulsing DC power is transformed from the first voltage to the second voltage based at least in part on a ratio of turns between the first and second resonant coils.

3. The system as recited in claim 1, wherein the first and second resonant coils are configured with a first number of turns and a second number of turns, respectively, a ratio of the first and second number of turns configured to at least partially control an amount of voltage scaling achieved between the first and second voltages in connection with the transforming.

4. The system as recited in claim 1, wherein the DC power source comprises a solar panel.

5. The system as recited in claim 1, wherein the receiver further includes an output configured to supply a power grid with AC power having the second voltage.

6. The system as recited in claim 1, wherein:

the transmitter is located on an outside of a structure and the DC power source comprises a solar panel mounted on the outside of the structure;

the membrane of the wireless gap comprises at least one of a wall, a roof, a ceiling, a floor, or a window of the structure; and

the receiver is located within the structure.

7. The system as recited in claim 1, wherein the wireless gap corresponds to a fixed distance.

8. The system as recited in claim 1, wherein a size of the first resonant coil is based at least in part on a distance of the wireless gap.

9. The system as recited in claim 8, wherein the first resonant coil has a diameter at least twice as long as the distance of the wireless gap.

10. The system as recited in claim 1, wherein the transmitter is configured to generate a pulsing DC waveform of the pulsing DC power to shape an output current of the receiver.

11. The system as recited in claim 1, wherein the receiver further includes an inverter disposed between the receiving circuit and an output of the receiver, the inverter configured to invert the pulsing DC power to AC power suitable for use by the power recipient.

12. The system as recited in claim 11, wherein the power recipient is tied to a power grid or comprises the power grid.

13. The system as recited in claim 1, wherein the system is configured to adjust at least one of the first voltage at the transmitter or the second voltage at the receiver responsive to at least one communication between the transmitter and the receiver to attain a voltage level.

14. The system as recited in claim 13, wherein the system is configured to adjust at least one of the first voltage or the second voltage to attain the voltage level by adjusting at least one of the first tunable capacitor coupled to the first resonant coil or the second tunable capacitor coupled to the second resonant coil.

15. The system as recited in claim 1, wherein the second voltage corresponds to an open circuit voltage, the receiving circuit further includes a third tunable capacitor coupled to the second resonant coil, and the third tunable capacitor is tunable to adjust the second voltage to a third voltage.

16. A method for wirelessly transferring and transforming power across a wireless gap that includes a membrane, the method comprising:

converting, by a rectifier disposed in a transmitter, alternating current (AC) power to pulsing DC power;

supplying the pulsing DC power to a transmitting circuit disposed in the transmitter, the transmitting circuit including a first resonant coil coupled to a first tunable capacitor that is tunable to adjust a resonant frequency of the first resonant coil, the pulsing DC power causing the first resonant coil to resonate and to propagate a wireless field to a receiver located across the membrane of the wireless gap;

coupling to the wireless field by a second resonant coil of a receiving circuit disposed in the receiver, the receiving circuit including the second resonant coil coupled to a second tunable capacitor that is tunable to adjust a resonant frequency of the second resonant coil, said coupling causing the second resonant coil to resonate and to receive the pulsing DC power at the receiver; and

transforming the pulsing DC power across the wireless gap from a first voltage at the first resonant coil to a second voltage at the second resonant coil by using the first and second resonant coils as primary and secondary windings, respectively, of a transformer such that the pulsing DC power is suitable for use by a power recipient.

17. The method as recited in claim 16, further comprising:

obtaining, by the transmitter, DC power from a DC power source;

supplying the DC power to an inverter circuit disposed in the transmitter; and

inverting, by the inverter circuit, the DC power to the AC power.

18. The method as recited in claim 16, further comprising:

obtaining, by the transmitter, the AC power from an AC power source; and

supplying the AC power to the rectifier.

19. The method as recited in claim 16, further comprising rectifying, by a rectifier disposed in the receiver, AC power that is derived from the pulsing DC power at the receiver to DC power.

20. The method as recited in claim 16, further comprising outputting, by the receiver, power suitable for use by the power recipient by adjusting at least one of the first voltage at the transmitter or the second voltage at the receiver responsive to at least one communication between the transmitter and the receiver to attain a voltage level.

21. The method as recited in claim 20, wherein the power suitable for use by the power recipient comprises a voltage suitable for use by a grid-tied power recipient.

22. A method for configuring a system to wirelessly transfer and transform power across a wireless gap, the method comprising:

disposing a rectifier in a transmitter to convert alternating current (AC) power to pulsing DC power;

disposing a transmitting circuit in the transmitter to transmit the pulsing DC power produced by the rectifier, the transmitting circuit including;

a first resonant coil configured to resonate based on the pulsing DC power produced by the rectifier and to wirelessly transmit the pulsing DC power across the wireless gap; and

a first tunable capacitor coupled to the first resonant coil, the first tunable capacitor being tunable to adjust a resonant frequency of the first resonant coil for wirelessly transmitting the pulsing DC power;

disposing a receiving circuit in a receiver configured to be separated from the transmitter by the wireless gap, the receiving circuit including;

a second resonant coil configured to resonate based on resonance of the first resonant coil and to receive the wirelessly transmitted pulsing DC power at the receiver; and

a second tunable capacitor coupled to the second resonant coil, the second tunable capacitor being tunable to adjust a resonant frequency of the second resonant coil; and

tuning, using at least one of the first or second tunable capacitor, the transmitting circuit or the receiving circuit to enable the first and second resonant coils to serve as primary and secondary windings, respectively, of a transformer configured to transform the wirelessly transmitted pulsing DC power from a first voltage at the first resonant coil to a second voltage at the second resonant coil that is suitable for use by a power recipient.

23. The method as recited in claim 22, further comprising disposing an inverter circuit in the transmitter upstream from the rectifier to invert direct current (DC) power to generate the AC power.

24. The method as recited in claim 22, wherein the power recipient comprises an AC power recipient;

and further comprising disposing an inverter in the receiver downstream from the receiving circuit to invert the pulsing DC power received by the receiving circuit to AC power suitable for the AC power recipient.

25. The method as recited in claim 22, wherein the tuning comprises at least one of:

tuning the transmitting circuit using the first tunable capacitor responsive to at least one communication between the transmitter and the receiver that is indicative of a voltage level;

or

tuning the receiving circuit using the second tunable capacitor responsive to the at least one communication.

26. The method as recited in claim 25, wherein:

the receiving circuit includes a third tunable capacitor;

the second tunable capacitor is coupled to one side of the second resonant coil, and the third tunable capacitor is coupled to another side of the second resonant coil;

the one side of the second resonant coil corresponds to the second voltage, and the other side of the second resonant coil corresponds to a third voltage; and

the method further comprises adjusting the third voltage by tuning the third tunable capacitor.

27. The method as recited in claim 22, further comprising coupling an input of the transmitter to a power source to supply power for transfer from the transmitter to the receiver across the wireless gap.

28. An apparatus for wirelessly transferring and transforming power across a wireless gap that includes a membrane, the apparatus comprising:

inverting means for inverting direct current (DC) power obtained from a DC power source to alternating current (AC) power;

rectifying means for rectifying the AC power to pulsing DC power;

transmitting means coupled to the rectifying means and having first resonant means for resonating at least near a frequency of the pulsing DC power produced by the rectifying means to wirelessly transmit the pulsing DC power across the membrane of the wireless gap, the transmitting means including first capacitive means for tuning a first capacitance coupled to the first resonant means; and

receiving means separated from the transmitting means by the wireless gap and having second resonant means for resonating based on resonance of the first resonant means to receive the wirelessly transmitted pulsing DC power, the receiving means including second capacitive means for tuning a second capacitance coupled to the second resonant means,

the first and second resonant means being further for transforming, across the wireless gap, the wirelessly transmitted pulsing DC power from a first voltage at the first resonant means to a second voltage at the second resonant means that is suitable for use by a power recipient.

29. The apparatus as recited in claim 28, further comprising communication means integral with the transmitting means and the receiving means for communicating to adjust at least one of:

the resonance of the first resonant means to change the frequency of the wirelessly transmitted pulsing DC power using the first capacitive means;

the resonance of the first resonant means at which the second resonant means is configured to resonate using the second capacitive means;

the first voltage;

or

the second voltage.

30. The apparatus as recited in claim 29, further comprising controlling means integral with at least one of the transmitting means or the receiving means for handling at least one adjustment in accordance with at least one communication that is communicated by the communication means between the transmitting means and the receiving means.