Devices, systems, and method for power control of dynamic electric vehicle charging systems

• US 9,608,465 B2
• Filed: 08/29/2014
• Issued: 03/28/2017
• Est. Priority Date: 04/18/2014
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Keeling, Nicholas Athol, Camasca Ramirez, Claudio Armando, Beaver, Jonathan, Huang, Chang-Yu, Budhia, Mickel Bipin, Kissin, Michael Le Gallais
• Primary Examiner(s): Muralidar, Richard V
• Application Number:
  US14/472,856
• Publication Number:
  US 20150303714A1
• Time in Patent Office: 942 Days
• Field of Search: 320/108
• US Class Current: 1/1
• CPC Class Codes: B60L 53/00 Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
• 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 53/66 Data transfer between charging stations and vehicles
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• 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 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

Abstract

Systems, methods, and apparatus are disclosed for wirelessly charging an electric vehicle. In one aspect, a method of wirelessly charging an electric vehicle is provided. The method includes, obtaining a request from the electric vehicle for a level of charging power to be delivered from a power transmitter to the electric vehicle via a charging field. The method further includes controlling a current or voltage of the power transmitter based on a power efficiency factor and the requested level of charging power.

Claims

1. An apparatus for wirelessly charging an electric vehicle, comprising:

a communication receiver configured to obtain a request for a level of charging power, wherein the request indicates a level of charging power to be delivered from a power antenna circuit to the electric vehicle via a charging field; and

a controller operationally coupled to the communication receiver and configured to control a current or voltage generator of the power antenna circuit based on a power efficiency factor and the requested level of charging power, wherein the power efficiency factor during a first time period is determined without receiving an amount of power measurement at the electric vehicle during the first time period.

2. The apparatus of claim 1, wherein the power efficiency factor is based at least in part on a pre-programmed value retrievable by the controller.

3. The apparatus of claim 2, wherein the pre-programmed value comprises a value of a lookup table comprising different pre-programmed values for different charging power levels.

4. The apparatus of claim 1, wherein the power efficiency factor comprises a determination of an efficiency of at least the power delivered by the power antenna circuit to a receive antenna and a rectifier circuit of the electric vehicle.

5. The apparatus of claim 1, further comprising a sensor configured to measure a current or voltage of the power antenna circuit.

6. The apparatus of claim 5, wherein the controller is further configured to adjust the power efficiency factor based on the measured current or voltage of the power antenna circuit.

7. The apparatus of claim 1, wherein the communication receiver is further configured to receive an output power measurement or an output error value from the electric vehicle.

8. The apparatus of claim 7, wherein the controller is further configured to adjust the power efficiency factor based on the output power measurement or the output error value.

9. The apparatus of claim 7, wherein the controller is further configured to control the current or voltage generator based on the power efficiency factor during a first time period, and wherein the output power measurement is received after the first time period.

10. The apparatus of claim 7, wherein the output error value comprises a difference between the output power measurement of the electric vehicle and the requested level of charging power, and wherein the output power measurement comprises a measurement of a level of charging power delivered to a load of the electric vehicle from the power antenna circuit.

11. The apparatus of claim 7, wherein the controller is further configured to control the current or voltage generator of the power antenna circuit based on a ratio of an input power of the power antenna circuit and the output power measurement.

12. The apparatus of claim 11, wherein an initial value of the ratio comprises a pre-programmed value retrievable by the controller.

13. The apparatus of claim 11, wherein the controller is further configured to adjust the ratio based on the output power measurement or the output error value.

14. The apparatus of claim 1, wherein the controller is further configured to control the current or voltage generator of the power antenna circuit based on a change in an electrical characteristic of the power antenna circuit or a receive circuit of the electric vehicle.

15. The apparatus of claim 14, wherein the electrical characteristic comprises at least one of a current, or an impedance, or a voltage, or a resistance, or a inductance, or resonant frequency, or a phase, or any combination thereof.

16. A method for wirelessly charging an electric vehicle, comprising:

obtaining a request from the electric vehicle for a level of charging power, wherein the request indicates a level of charging power to be delivered from a power transmitter to the electric vehicle via a charging field; and

controlling a current or voltage of the power transmitter based on a power efficiency factor and the requested level of charging power, wherein the power efficiency factor during a first time period is determined without receiving an amount of power measurement at the electric vehicle during the first time period.

17. The method of claim 16, wherein the power efficiency factor is based at least in part on a pre-programmed value retrievable by the controller.

18. The method of claim 16, wherein the power efficiency factor comprises a determination of an efficiency of at least the power delivered by the power antenna circuit to a receive antenna and a rectifier circuit of the electric vehicle.

19. The method of claim 16, further comprising adjusting the power efficiency factor based on a measured current or voltage of the power transmitter.

20. The method of claim 16, further comprising receiving an output power measurement or an output error value from the electric vehicle.

21. The method of claim 20, further comprising adjusting the power efficiency factor based on the output power measurement or the output error value.

22. The method of claim 20, wherein controlling a current or voltage of the power transmitter comprises controlling a current or voltage of the power transmitter based on a ratio of an input power of the power antenna circuit and the output power measurement.

23. The method of claim 22, wherein controlling a current or voltage of the power transmitter comprises controlling a current or voltage of the power transmitter based on the output power measurement or the output error value.

24. The method of claim 16, wherein controlling a current or voltage of the power transmitter comprises controlling a current or voltage of the power transmitter based on a change in an electrical characteristic of the power transmitter or the electric vehicle.

25. The method of claim 24, wherein the electrical characteristic comprises at least one of a current, or an impedance, or a voltage, or a resistance, or a inductance, or resonant frequency, or a phase, or any combination thereof.

26. An apparatus for wirelessly charging an electric vehicle, comprising:

means for obtaining a request from the electric vehicle for a level of charging power, wherein the request indicates a level of charging power to be delivered from a power antenna circuit to the electric vehicle via a charging field; and

means for controlling a current or a voltage of the power antenna circuit based on a power efficiency factor and the requested level of charging power, wherein the power efficiency factor during a first time period is determined without receiving an amount of power measurement at the electric vehicle during the first time period.

27. The apparatus of claim 26, wherein the obtaining means comprises a receiver, wherein the controlling means comprises a controller.

28. The apparatus of claim 26, further comprising adjusting the power efficiency factor based on a measured current or voltage of the power antenna circuit.

29. The apparatus of claim 26, further comprising:

means for receiving an output power measurement or an output error value from the electric vehicle; and

means for adjusting the power efficiency factor based on the output power measurement or the output error value.