Wireless energy transfer systems

• US 8,461,719 B2
• Filed: 09/25/2009
• Issued: 06/11/2013
• Est. Priority Date: 09/27/2008
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Kesler, Morris P., Karalis, Aristeidis, Kurs, Andre B., Campanella, Andrew J., Fiorello, Ron, Li, Qiang, Giler, Eric R., Pergal, Frank J., Schatz, David A., Hall, Katherine L., Soljacic, Marin, Kulikowski, Konrad
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US12/567,716
• Publication Number:
  US 20100141042A1
• Time in Patent Office: 1,355 Days
• Field of Search: 307/104
• US Class Current: 307/104
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2200/22 Microcars, e.g. golf cars
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 2260/28 Four wheel or all wheel drive
• CPC Class Codes: B60L 2260/32 Auto pilot mode
• CPC Class Codes: B60L 50/20 using propulsion power generated by humans or animals
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: B60L 53/51 Photovoltaic means
• CPC Class Codes: B60L 53/63 in response to network capacity
• CPC Class Codes: B60L 53/64 Optimising energy costs, e.g. responding to electricity rates
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 53/665 Methods related to measuring, billing or payment
• CPC Class Codes: B60L 55/00 : Arrangements for supplying energy stored within a vehicle to a power network, i.e. vehicle-to-grid [V2G] arrangements
• 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 2310/40 : The network being an on-board power network, i.e. within a vehicle
• CPC Class Codes: H02J 50/12 : of the resonant type
• CPC Class Codes: H02J 50/402 : the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• 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 7/00 : Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/35 : with light sensitive cells
• CPC Class Codes: H03H 7/40 : Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 5/266 : One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/79 : for data transfer in combination with power transfer
• CPC Class Codes: Y02E 60/00 : Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 10/126 : the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

Described herein are improved capabilities for a source resonator having a Q-factor Q₁>100 and a characteristic size x₁ coupled to an energy source, and a second resonator having a Q-factor Q₂>100 and a characteristic size x₂ coupled to an energy drain located a distance D from the source resonator, where the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator.

Claims

1. A system, comprising:

a source resonator having a Q-factor Q₁ and a characteristic size x₁, coupled to a power generator with direct electrical connections; and

a second resonator having a Q-factor Q₂ and a characteristic size x₂, coupled to a load with a second direct electrical connection, and located a distance D from the source resonator, wherein the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator in order to transmit power from the power generator to the load, wherein √

{square root over (Q₁Q₂)} is greater than 100, wherein at least one of the source resonator and the second resonator is a coil of at least one turn of a conducting material connected to a first network of capacitors, and wherein the direct electrical connections of at least one of the source resonator to the ground terminal of the power generator and the second resonator to the ground terminal of the load is made at a point on an axis of electrical symmetry of the first network of capacitors.

2. The system of claim 1, wherein the first network of capacitors includes at least one tunable butterfly-type capacitor, wherein the direct electrical connection to the ground terminal is made on a center terminal of the at least one tunable butterfly-type capacitor.

3. The system of claim 1, wherein the direct electrical connection of at least one of the source resonator to the power generator and the second resonator to the load is made via a second network of capacitors, wherein the first network of capacitors and the second network of capacitors form an impedance matching network.

4. The system of claim 3, wherein the impedance matching network is designed to match the coil to a characteristic impedance of the power generator or the load at a driving frequency of the power generator.

5. The system of claim 3, wherein at least one of the first network of capacitors and the second network of capacitors includes at least one tunable capacitor.

6. The system of claim 5, wherein the first network of capacitors and the second network of capacitors are adjustable to change an impedance of the impedance matching network at a driving frequency of the power generator.

7. The system of claim 5, wherein the first network of capacitors and the second network of capacitors are adjustable to match the coil to the characteristic impedance of the power generator or the load at a driving frequency of the power generator.

8. The system of claim 5, wherein at least one of the first network of capacitors and the second network of capacitors includes at least one fixed capacitor that reduces a voltage across the at least one tunable capacitor.

9. The system of claim 1, wherein the direct electrical connections of at least one of the source resonator to the power generator and the second resonator to the load are configured to substantially preserve a resonant mode.

10. The system of claim 1, wherein at least one of the source resonator and the second resonator is a tunable resonator.

11. The system of claim 1, wherein the source resonator is physically separated from the power generator and the second resonator is physically separated from the load.

12. The system of claim 1, wherein the second resonator is coupled to a power conversion circuit to deliver DC power to the load.

13. The system of claim 1, wherein the second resonator is coupled to a power conversion circuit to deliver AC power to the load.

14. The system of claim 1, wherein the second resonator is coupled to a power conversion circuit to deliver both AC and DC power to the load.

15. The system of claim 1, wherein the second resonator is coupled to a power conversion circuit to deliver power to a plurality of loads.

16. A system, comprising:

a source resonator having a Q-factor Q₁ and a characteristic size x₁, and a second resonator having a Q-factor Q₂ and a characteristic size x₂, and located a distance D from the source resonator;

wherein the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator; and

wherein √

{square root over (Q₁Q₂)} is greater than 100, and wherein at least one of the resonators is enclosed in a low loss tangent material.

17. A system, comprising:

a source resonator having a Q-factor Q₁ and a characteristic size x₁, and a second resonator having a Q-factor Q₂ and a characteristic size x₂, and located a distance D from the source resonator;

wherein the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator, and wherein √

{square root over (Q₁Q₂)} is greater than 100; and

wherein at least one of the resonators includes a coil of a plurality of turns of a conducting material connected to a network of capacitors, wherein the plurality of turns are in a common plane, and wherein a characteristic thickness of the at least one of the resonators is much less than a characteristic size of the at least one of the resonators.