Wireless Power Transfer for Stationary Applications

• US 20180205263A1
• Filed: 01/19/2017
• Published: 07/19/2018
• Est. Priority Date: 01/19/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: von Novak, III, William Henry
• Granted Patent: US 10,742,071 B2
• Time in Patent Office: 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 transmitting circuit having a first resonant coil configured to resonate at a frequency of the AC power and to wirelessly transmit the AC power across the membrane of the wireless gap; 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 AC power,

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 AC 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 AC power is transformed from the first voltage to the second voltage based 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 coil are configured with a first and second ratio of turns, respectively, the first and second ratio of turns configured to 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 is 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 outside 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, roof, ceiling, floor, or 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 receiver further includes a rectifier disposed between the receiving circuit and an output of the receiver, the rectifier configured to rectify the wirelessly transmitted AC power to DC power.

11. The system as recited in claim 10, wherein the receiver further includes an inverter disposed between the rectifier and the output of the receiver, the rectifier configured to rectify the 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 transmitting circuit further includes a tunable capacitor coupled to the first resonant coil, the tunable capacitor being tunable to adjust a resonant frequency of the first resonant coil of the transmitting circuit for wirelessly transmitting the AC power.

14. The system as recited in claim 1, wherein the receiving circuit further includes a tunable capacitor coupled to the second resonant coil, the tunable capacitor being tunable to adjust a resonant frequency of 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 tunable capacitor coupled to the second resonant coil, and the 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:

inverting, by an inverter circuit disposed in a transmitter, direct current (DC) power to alternating current (AC) power;

supplying the AC power to a transmitting circuit disposed in the transmitter, the AC power causing a first resonant coil disposed in the transmitting circuit 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, said coupling causing the second resonant coil to resonate and to receive the AC power at the receiver; and

transforming the AC 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.

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

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

supplying the DC power to the inverter circuit. QUALCOMM Incorporated 45 Docket No.;

151871

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

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

rectifying, by a rectifier disposed in the transmitter, the obtained AC power to the DC power; and

supplying the DC power to the inverter circuit.

19. The method as recited in claim 16, further comprising rectifying, by a rectifier disposed in the receiver, the AC power received 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 a power recipient.

21. The method as recited in claim 20, wherein the power suitable for use by the power recipient is AC power 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 an inverter circuit in a transmitter to invert direct current (DC) power to generate alternating current (AC) power;

disposing a transmitting circuit in the transmitter to transmit the AC power generated by the inverter circuit, the transmitting circuit having a first resonant coil configured to resonate based on the AC power generated by the inverter circuit and to wirelessly transmit the AC power across the wireless gap;

disposing a receiving circuit in a receiver configured to be separated from the transmitter by the wireless gap, the receiving circuit having a second resonant coil configured to resonate based on resonance of the first resonant coil and to receive the wirelessly transmitted AC power at the receiver; and

tuning the transmitting circuit and 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 AC power from a first voltage at the first resonant coil to a second voltage at the second resonant coil.

23. The method as recited in claim 22, further comprising disposing a rectifier in the receiver downstream from the receiving circuit to rectify the received AC power to generate DC power.

24. The method as recited in claim 23, further comprising disposing an inverter in the receiver downstream from the rectifier to invert the DC power generated by the rectifier to AC power suitable for an AC power recipient.

25. The method as recited in claim 24, wherein the AC power recipient is a power grid operated by a utility company or is tied to the power grid.

26. The method as recited in claim 22, further comprising disposing a rectifier in the receiver between an input of the receiver and the inverter circuit, the rectifier configured to rectify power received via the input from an AC power source to the DC power.

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:

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

a transmitting means coupled to the inverting means and having a first resonant means for resonating near a frequency of the AC power generated by the inverting means to wirelessly transmit the AC power across the membrane of the wireless gap; and

a receiving means separated from the transmitting means by the wireless gap and having a second resonant means for resonating based on resonance of the first resonant means to receive the wirelessly transmitted AC power,

the first and second resonant means being further for transforming, across the wireless gap, the wirelessly transmitted AC 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 resonating means to change the frequency of the wirelessly transmitted AC power;

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

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 the adjustments in accordance with the communicating.